Fix initializer list initialization for GCC-15 (#5443)

- Specification: XRPLF/XRPL-Standards#239
- Amendment: `SingleAssetVault`
- Implements a vault feature used to store a fungible asset (XRP, IOU, or MPT, but not NFT) and to receive shares in the vault (an MPT) in exchange.
- A vault can be private or public.
- A private vault can use permissioned domains, subject to the `PermissionedDomains` amendment.
- Shares can be exchanged back into asset with `VaultWithdraw`.
- Permissions on the asset in the vault are transitively applied on shares in the vault.
- Issuer of the asset in the vault can clawback with `VaultClawback`.
- Extended `MPTokenIssuance` with `DomainID`, used by the permissioned domain on the vault shares.

Co-authored-by: John Freeman <jfreeman08@gmail.com>

.clang-format

@@ -44,6 +44,7 @@ DerivePointerAlignment: false
 DisableFormat:   false
 ExperimentalAutoDetectBinPacking: false
 ForEachMacros:   [ Q_FOREACH,  BOOST_FOREACH ]
+IncludeBlocks:   Regroup
 IncludeCategories:
   - Regex:           '^<(test)/'
     Priority:        0
@@ -53,8 +54,12 @@ IncludeCategories:
     Priority:        2
   - Regex:           '^<(boost)/'
     Priority:        3
-  - Regex:           '.*'
+  - Regex:           '^.*/'
     Priority:        4
+  - Regex:           '^.*\.h'
+    Priority:        5
+  - Regex:           '.*'
+    Priority:        6
 IncludeIsMainRegex: '$'
 IndentCaseLabels: true
 IndentFunctionDeclarationAfterType: false
@@ -89,3 +94,4 @@ SpacesInSquareBrackets: false
 Standard:        Cpp11
 TabWidth:        8
 UseTab:          Never
+QualifierAlignment: Right

.github/workflows/clang-format.yml

@@ -20,7 +20,7 @@ jobs:
         sudo apt-get update
         sudo apt-get install clang-format-${CLANG_VERSION}
     - name: Format first-party sources
-      run: find include src -type f \( -name '*.cpp' -o -name '*.hpp' -o -name '*.h' -o -name '*.ipp' \) -not -path "src/magic/magic_enum.h" -exec clang-format-${CLANG_VERSION} -i {} +
+      run: find include src tests -type f \( -name '*.cpp' -o -name '*.hpp' -o -name '*.h' -o -name '*.ipp' \) -not -path "src/magic/magic_enum.h" -exec clang-format-${CLANG_VERSION} -i {} +
     - name: Check for differences
       id: assert
       run: |

API-CHANGELOG.md

@@ -83,9 +83,17 @@ The [commandline](https://xrpl.org/docs/references/http-websocket-apis/api-conve
 
 The `network_id` field was added in the `server_info` response in version 1.5.0 (2019), but it is not returned in [reporting mode](https://xrpl.org/rippled-server-modes.html#reporting-mode). However, use of reporting mode is now discouraged, in favor of using [Clio](https://github.com/XRPLF/clio) instead.
 
+## XRP Ledger server version 2.5.0
+
+As of 2025-04-04, version 2.5.0 is in development. You can use a pre-release version by building from source or [using the `nightly` package](https://xrpl.org/docs/infrastructure/installation/install-rippled-on-ubuntu).
+
+### Additions and bugfixes in 2.5.0
+
+- `channel_authorize`: If `signing_support` is not enabled in the config, the RPC is disabled.
+
 ## XRP Ledger server version 2.4.0
 
-As of 2025-01-28, version 2.4.0 is in development. You can use a pre-release version by building from source or [using the `nightly` package](https://xrpl.org/docs/infrastructure/installation/install-rippled-on-ubuntu).
+[Version 2.4.0](https://github.com/XRPLF/rippled/releases/tag/2.4.0) was released on March 4, 2025.
 
 ### Additions and bugfixes in 2.4.0
 

Builds/levelization/results/loops.txt

@@ -29,7 +29,7 @@ Loop: xrpld.app xrpld.overlay
   xrpld.overlay ~= xrpld.app
 
 Loop: xrpld.app xrpld.peerfinder
-  xrpld.app > xrpld.peerfinder
+  xrpld.peerfinder ~= xrpld.app
 
 Loop: xrpld.app xrpld.rpc
   xrpld.rpc > xrpld.app
@@ -44,7 +44,7 @@ Loop: xrpld.core xrpld.perflog
   xrpld.perflog == xrpld.core
 
 Loop: xrpld.net xrpld.rpc
-  xrpld.rpc > xrpld.net
+  xrpld.rpc ~= xrpld.net
 
 Loop: xrpld.overlay xrpld.rpc
   xrpld.rpc ~= xrpld.overlay

Builds/levelization/results/ordering.txt

@@ -7,6 +7,7 @@ libxrpl.protocol > xrpl.hook
 libxrpl.protocol > xrpl.json
 libxrpl.protocol > xrpl.protocol
 libxrpl.resource > xrpl.basics
+libxrpl.resource > xrpl.json
 libxrpl.resource > xrpl.resource
 libxrpl.server > xrpl.basics
 libxrpl.server > xrpl.json
@@ -43,6 +44,7 @@ test.consensus > xrpld.app
 test.consensus > xrpld.consensus
 test.consensus > xrpld.core
 test.consensus > xrpld.ledger
+test.consensus > xrpl.json
 test.consensus > xrpl.protocol
 test.core > test.jtx
 test.core > test.toplevel
@@ -60,7 +62,6 @@ test.json > test.jtx
 test.json > xrpl.json
 test.jtx > xrpl.basics
 test.jtx > xrpld.app
-test.jtx > xrpld.consensus
 test.jtx > xrpld.core
 test.jtx > xrpld.ledger
 test.jtx > xrpld.net
@@ -167,7 +168,6 @@ xrpld.core > xrpl.basics
 xrpld.core > xrpl.json
 xrpld.core > xrpl.protocol
 xrpld.ledger > xrpl.basics
-xrpld.ledger > xrpld.core
 xrpld.ledger > xrpl.json
 xrpld.ledger > xrpl.protocol
 xrpld.net > xrpl.basics
@@ -192,7 +192,6 @@ xrpld.peerfinder > xrpld.core
 xrpld.peerfinder > xrpl.protocol
 xrpld.perflog > xrpl.basics
 xrpld.perflog > xrpl.json
-xrpld.perflog > xrpl.protocol
 xrpld.rpc > xrpl.basics
 xrpld.rpc > xrpld.core
 xrpld.rpc > xrpld.ledger
@@ -203,6 +202,5 @@ xrpld.rpc > xrpl.protocol
 xrpld.rpc > xrpl.resource
 xrpld.rpc > xrpl.server
 xrpld.shamap > xrpl.basics
-xrpld.shamap > xrpld.core
 xrpld.shamap > xrpld.nodestore
 xrpld.shamap > xrpl.protocol

CMakeLists.txt

@@ -21,6 +21,18 @@ endif()
 project (xrpl)
 set(Boost_NO_BOOST_CMAKE ON)
 
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU")
+    # GCC-specific fixes
+    add_compile_options(-Wno-unknown-pragmas -Wno-subobject-linkage)
+    # -Wno-subobject-linkage can be removed when we upgrade GCC version to at least 13.3
+elseif(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+    # Clang-specific fixes
+    add_compile_options(-Wno-unknown-warning-option) # Ignore unknown warning options
+elseif(MSVC)
+    # MSVC-specific fixes
+    add_compile_options(/wd4068) # Ignore unknown pragmas
+endif()
+
 # make GIT_COMMIT_HASH define available to all sources
 find_package(Git)
 if(Git_FOUND)

cmake/RippledCore.cmake

@@ -152,6 +152,9 @@ if(xrpld)
   add_executable(rippled)
   if(tests)
     target_compile_definitions(rippled PUBLIC ENABLE_TESTS)
+    target_compile_definitions(rippled PRIVATE
+                                       UNIT_TEST_REFERENCE_FEE=${UNIT_TEST_REFERENCE_FEE}
+    )
   endif()
   target_include_directories(rippled
     PRIVATE

cmake/RippledSettings.cmake

@@ -11,6 +11,12 @@ option(assert "Enables asserts, even in release builds" OFF)
 option(xrpld "Build xrpld" ON)
 
 option(tests "Build tests" ON)
+if(tests)
+  # This setting allows making a separate workflow to test fees other than default 10
+  if(NOT UNIT_TEST_REFERENCE_FEE)
+    set(UNIT_TEST_REFERENCE_FEE "10" CACHE STRING "")
+  endif()
+endif()
 
 option(unity "Creates a build using UNITY support in cmake. This is the default" ON)
 if(unity)

conanfile.py

@@ -123,7 +123,7 @@ class Xrpl(ConanFile):
         if self.options.jemalloc:
             self.requires('jemalloc/5.3.0')
         if self.options.rocksdb:
-            self.requires('rocksdb/6.29.5')
+            self.requires('rocksdb/9.7.3')
 
     exports_sources = (
         'CMakeLists.txt',

external/rocksdb/conandata.yml

@@ -1,27 +1,12 @@
 sources:
-  "6.29.5":
-    url: "https://github.com/facebook/rocksdb/archive/refs/tags/v6.29.5.tar.gz"
-    sha256: "ddbf84791f0980c0bbce3902feb93a2c7006f6f53bfd798926143e31d4d756f0"
-  "6.27.3":
-    url: "https://github.com/facebook/rocksdb/archive/refs/tags/v6.27.3.tar.gz"
-    sha256: "ee29901749b9132692b26f0a6c1d693f47d1a9ed8e3771e60556afe80282bf58"
-  "6.20.3":
-    url: "https://github.com/facebook/rocksdb/archive/refs/tags/v6.20.3.tar.gz"
-    sha256: "c6502c7aae641b7e20fafa6c2b92273d935d2b7b2707135ebd9a67b092169dca"
-  "8.8.1":
-    url: "https://github.com/facebook/rocksdb/archive/refs/tags/v8.8.1.tar.gz"
-    sha256: "056c7e21ad8ae36b026ac3b94b9d6e0fcc60e1d937fc80330921e4181be5c36e"
+  "9.7.3":
+    url: "https://github.com/facebook/rocksdb/archive/refs/tags/v9.7.3.tar.gz"
+    sha256: "acfabb989cbfb5b5c4d23214819b059638193ec33dad2d88373c46448d16d38b"
 patches:
-  "6.29.5":
-    - patch_file: "patches/6.29.5-0001-add-include-cstdint-for-gcc-13.patch"
-      patch_description: "Fix build with gcc 13 by including cstdint"
-      patch_type: "portability"
-      patch_source: "https://github.com/facebook/rocksdb/pull/11118"
-    - patch_file: "patches/6.29.5-0002-exclude-thirdparty.patch"
+  "9.7.3":
+    - patch_file: "patches/9.x.x-0001-exclude-thirdparty.patch"
       patch_description: "Do not include thirdparty.inc"
       patch_type: "portability"
-  "6.27.3":
-    - patch_file: "patches/6.27.3-0001-add-include-cstdint-for-gcc-13.patch"
-      patch_description: "Fix build with gcc 13 by including cstdint"
+    - patch_file: "patches/9.7.3-0001-memory-leak.patch"
+      patch_description: "Fix a leak of obsolete blob files left open until DB::Close()"
       patch_type: "portability"
-      patch_source: "https://github.com/facebook/rocksdb/pull/11118"

external/rocksdb/conanfile.py

@@ -15,10 +15,10 @@ required_conan_version = ">=1.53.0"
 
 class RocksDBConan(ConanFile):
     name = "rocksdb"
-    homepage = "https://github.com/facebook/rocksdb"
+    description = "A library that provides an embeddable, persistent key-value store for fast storage"
     license = ("GPL-2.0-only", "Apache-2.0")
     url = "https://github.com/conan-io/conan-center-index"
-    description = "A library that provides an embeddable, persistent key-value store for fast storage"
+    homepage = "https://github.com/facebook/rocksdb"
     topics = ("database", "leveldb", "facebook", "key-value")
     package_type = "library"
     settings = "os", "arch", "compiler", "build_type"
@@ -58,12 +58,12 @@ class RocksDBConan(ConanFile):
     @property
     def _compilers_minimum_version(self):
         return {} if self._min_cppstd == "11" else {
-                "apple-clang": "10",
-                "clang": "7",
-                "gcc": "7",
-                "msvc": "191",
-                "Visual Studio": "15",
-            }
+            "apple-clang": "10",
+            "clang": "7",
+            "gcc": "7",
+            "msvc": "191",
+            "Visual Studio": "15",
+        }
 
     def export_sources(self):
         export_conandata_patches(self)
@@ -115,9 +115,9 @@ class RocksDBConan(ConanFile):
         check_min_vs(self, "191")
 
         if self.version == "6.20.3" and \
-           self.settings.os == "Linux" and \
-           self.settings.compiler == "gcc" and \
-           Version(self.settings.compiler.version) < "5":
+                self.settings.os == "Linux" and \
+                self.settings.compiler == "gcc" and \
+                Version(self.settings.compiler.version) < "5":
             raise ConanInvalidConfiguration("Rocksdb 6.20.3 is not compilable with gcc <5.") # See https://github.com/facebook/rocksdb/issues/3522
 
     def source(self):
@@ -163,6 +163,8 @@ class RocksDBConan(ConanFile):
         if self.options.with_jemalloc:
             deps.set_property("jemalloc", "cmake_file_name", "JeMalloc")
             deps.set_property("jemalloc", "cmake_target_name", "JeMalloc::JeMalloc")
+        if self.options.with_zstd:
+            deps.set_property("zstd", "cmake_target_name", "zstd::zstd")
         deps.generate()
 
     def build(self):

external/rocksdb/patches/6.29.5-0001-add-include-cstdint-for-gcc-13.patch

@@ -1,30 +0,0 @@
---- a/include/rocksdb/utilities/checkpoint.h
-+++ b/include/rocksdb/utilities/checkpoint.h
-@@ -8,6 +8,7 @@
- #pragma once
- #ifndef ROCKSDB_LITE
- 
-+#include <cstdint>
- #include <string>
- #include <vector>
- #include "rocksdb/status.h"
---- a/table/block_based/data_block_hash_index.h
-+++ b/table/block_based/data_block_hash_index.h
-@@ -5,6 +5,7 @@
- 
- #pragma once
- 
-+#include <cstdint>
- #include <string>
- #include <vector>
- 
---- a/util/string_util.h
-+++ b/util/string_util.h
-@@ -6,6 +6,7 @@
- 
- #pragma once
- 
-+#include <cstdint>
- #include <sstream>
- #include <string>
- #include <unordered_map>

external/rocksdb/patches/6.29.5-0002-exclude-thirdparty.patch

@@ -1,16 +0,0 @@
-diff --git a/CMakeLists.txt b/CMakeLists.txt
-index ec59d4491..35577c998 100644
---- a/CMakeLists.txt
-+++ b/CMakeLists.txt
-@@ -101 +100,0 @@ if(MSVC)
--  option(WITH_GFLAGS "build with GFlags" OFF)
-@@ -103,2 +102,2 @@ if(MSVC)
--  include(${CMAKE_CURRENT_SOURCE_DIR}/thirdparty.inc)
--else()
-+endif()
-+
-@@ -117 +116 @@ else()
--  if(MINGW)
-+  if(MINGW OR MSVC)
-@@ -183 +181,0 @@ else()
--endif()

external/rocksdb/patches/9.7.3-0001-memory-leak.patch

@@ -0,0 +1,319 @@
+diff --git a/HISTORY.md b/HISTORY.md
+index 36d472229..05ad1a202 100644
+--- a/HISTORY.md
++++ b/HISTORY.md
+@@ -1,6 +1,10 @@
+ # Rocksdb Change Log
+ > NOTE: Entries for next release do not go here. Follow instructions in `unreleased_history/README.txt`
+ 
++## 9.7.4 (10/31/2024)
++### Bug Fixes
++* Fix a leak of obsolete blob files left open until DB::Close(). This bug was introduced in version 9.4.0.
++
+ ## 9.7.3 (10/16/2024)
+ ### Behavior Changes
+ * OPTIONS file to be loaded by remote worker is now preserved so that it does not get purged by the primary host. A similar technique as how we are preserving new SST files from getting purged is used for this. min_options_file_numbers_ is tracked like pending_outputs_ is tracked.
+diff --git a/db/blob/blob_file_cache.cc b/db/blob/blob_file_cache.cc
+index 5f340aadf..1b9faa238 100644
+--- a/db/blob/blob_file_cache.cc
++++ b/db/blob/blob_file_cache.cc
+@@ -42,6 +42,7 @@ Status BlobFileCache::GetBlobFileReader(
+   assert(blob_file_reader);
+   assert(blob_file_reader->IsEmpty());
+ 
++  // NOTE: sharing same Cache with table_cache
+   const Slice key = GetSliceForKey(&blob_file_number);
+ 
+   assert(cache_);
+@@ -98,4 +99,13 @@ Status BlobFileCache::GetBlobFileReader(
+   return Status::OK();
+ }
+ 
++void BlobFileCache::Evict(uint64_t blob_file_number) {
++  // NOTE: sharing same Cache with table_cache
++  const Slice key = GetSliceForKey(&blob_file_number);
++
++  assert(cache_);
++
++  cache_.get()->Erase(key);
++}
++
+ }  // namespace ROCKSDB_NAMESPACE
+diff --git a/db/blob/blob_file_cache.h b/db/blob/blob_file_cache.h
+index 740e67ada..6858d012b 100644
+--- a/db/blob/blob_file_cache.h
++++ b/db/blob/blob_file_cache.h
+@@ -36,6 +36,15 @@ class BlobFileCache {
+                            uint64_t blob_file_number,
+                            CacheHandleGuard<BlobFileReader>* blob_file_reader);
+ 
++  // Called when a blob file is obsolete to ensure it is removed from the cache
++  // to avoid effectively leaking the open file and assicated memory
++  void Evict(uint64_t blob_file_number);
++
++  // Used to identify cache entries for blob files (not normally useful)
++  static const Cache::CacheItemHelper* GetHelper() {
++    return CacheInterface::GetBasicHelper();
++  }
++
+  private:
+   using CacheInterface =
+       BasicTypedCacheInterface<BlobFileReader, CacheEntryRole::kMisc>;
+diff --git a/db/column_family.h b/db/column_family.h
+index e4b7adde8..86637736a 100644
+--- a/db/column_family.h
++++ b/db/column_family.h
+@@ -401,6 +401,7 @@ class ColumnFamilyData {
+                          SequenceNumber earliest_seq);
+ 
+   TableCache* table_cache() const { return table_cache_.get(); }
++  BlobFileCache* blob_file_cache() const { return blob_file_cache_.get(); }
+   BlobSource* blob_source() const { return blob_source_.get(); }
+ 
+   // See documentation in compaction_picker.h
+diff --git a/db/db_impl/db_impl.cc b/db/db_impl/db_impl.cc
+index 261593423..06573ac2e 100644
+--- a/db/db_impl/db_impl.cc
++++ b/db/db_impl/db_impl.cc
+@@ -659,8 +659,9 @@ Status DBImpl::CloseHelper() {
+   // We need to release them before the block cache is destroyed. The block
+   // cache may be destroyed inside versions_.reset(), when column family data
+   // list is destroyed, so leaving handles in table cache after
+-  // versions_.reset() may cause issues.
+-  // Here we clean all unreferenced handles in table cache.
++  // versions_.reset() may cause issues. Here we clean all unreferenced handles
++  // in table cache, and (for certain builds/conditions) assert that no obsolete
++  // files are hanging around unreferenced (leak) in the table/blob file cache.
+   // Now we assume all user queries have finished, so only version set itself
+   // can possibly hold the blocks from block cache. After releasing unreferenced
+   // handles here, only handles held by version set left and inside
+@@ -668,6 +669,9 @@ Status DBImpl::CloseHelper() {
+   // time a handle is released, we erase it from the cache too. By doing that,
+   // we can guarantee that after versions_.reset(), table cache is empty
+   // so the cache can be safely destroyed.
++#ifndef NDEBUG
++  TEST_VerifyNoObsoleteFilesCached(/*db_mutex_already_held=*/true);
++#endif  // !NDEBUG
+   table_cache_->EraseUnRefEntries();
+ 
+   for (auto& txn_entry : recovered_transactions_) {
+@@ -3227,6 +3231,8 @@ Status DBImpl::MultiGetImpl(
+       s = Status::Aborted();
+       break;
+     }
++    // This could be a long-running operation
++    ROCKSDB_THREAD_YIELD_HOOK();
+   }
+ 
+   // Post processing (decrement reference counts and record statistics)
+diff --git a/db/db_impl/db_impl.h b/db/db_impl/db_impl.h
+index 5e4fa310b..ccc0abfa7 100644
+--- a/db/db_impl/db_impl.h
++++ b/db/db_impl/db_impl.h
+@@ -1241,9 +1241,14 @@ class DBImpl : public DB {
+   static Status TEST_ValidateOptions(const DBOptions& db_options) {
+     return ValidateOptions(db_options);
+   }
+-
+ #endif  // NDEBUG
+ 
++  // In certain configurations, verify that the table/blob file cache only
++  // contains entries for live files, to check for effective leaks of open
++  // files. This can only be called when purging of obsolete files has
++  // "settled," such as during parts of DB Close().
++  void TEST_VerifyNoObsoleteFilesCached(bool db_mutex_already_held) const;
++
+   // persist stats to column family "_persistent_stats"
+   void PersistStats();
+ 
+diff --git a/db/db_impl/db_impl_debug.cc b/db/db_impl/db_impl_debug.cc
+index 790a50d7a..67f5b4aaf 100644
+--- a/db/db_impl/db_impl_debug.cc
++++ b/db/db_impl/db_impl_debug.cc
+@@ -9,6 +9,7 @@
+ 
+ #ifndef NDEBUG
+ 
++#include "db/blob/blob_file_cache.h"
+ #include "db/column_family.h"
+ #include "db/db_impl/db_impl.h"
+ #include "db/error_handler.h"
+@@ -328,5 +329,49 @@ size_t DBImpl::TEST_EstimateInMemoryStatsHistorySize() const {
+   InstrumentedMutexLock l(&const_cast<DBImpl*>(this)->stats_history_mutex_);
+   return EstimateInMemoryStatsHistorySize();
+ }
++
++void DBImpl::TEST_VerifyNoObsoleteFilesCached(
++    bool db_mutex_already_held) const {
++  // This check is somewhat expensive and obscure to make a part of every
++  // unit test in every build variety. Thus, we only enable it for ASAN builds.
++  if (!kMustFreeHeapAllocations) {
++    return;
++  }
++
++  std::optional<InstrumentedMutexLock> l;
++  if (db_mutex_already_held) {
++    mutex_.AssertHeld();
++  } else {
++    l.emplace(&mutex_);
++  }
++
++  std::vector<uint64_t> live_files;
++  for (auto cfd : *versions_->GetColumnFamilySet()) {
++    if (cfd->IsDropped()) {
++      continue;
++    }
++    // Sneakily add both SST and blob files to the same list
++    cfd->current()->AddLiveFiles(&live_files, &live_files);
++  }
++  std::sort(live_files.begin(), live_files.end());
++
++  auto fn = [&live_files](const Slice& key, Cache::ObjectPtr, size_t,
++                          const Cache::CacheItemHelper* helper) {
++    if (helper != BlobFileCache::GetHelper()) {
++      // Skip non-blob files for now
++      // FIXME: diagnose and fix the leaks of obsolete SST files revealed in
++      // unit tests.
++      return;
++    }
++    // See TableCache and BlobFileCache
++    assert(key.size() == sizeof(uint64_t));
++    uint64_t file_number;
++    GetUnaligned(reinterpret_cast<const uint64_t*>(key.data()), &file_number);
++    // Assert file is in sorted live_files
++    assert(
++        std::binary_search(live_files.begin(), live_files.end(), file_number));
++  };
++  table_cache_->ApplyToAllEntries(fn, {});
++}
+ }  // namespace ROCKSDB_NAMESPACE
+ #endif  // NDEBUG
+diff --git a/db/db_iter.cc b/db/db_iter.cc
+index e02586377..bf4749eb9 100644
+--- a/db/db_iter.cc
++++ b/db/db_iter.cc
+@@ -540,6 +540,8 @@ bool DBIter::FindNextUserEntryInternal(bool skipping_saved_key,
+     } else {
+       iter_.Next();
+     }
++    // This could be a long-running operation due to tombstones, etc.
++    ROCKSDB_THREAD_YIELD_HOOK();
+   } while (iter_.Valid());
+ 
+   valid_ = false;
+diff --git a/db/table_cache.cc b/db/table_cache.cc
+index 71fc29c32..8a5be75e8 100644
+--- a/db/table_cache.cc
++++ b/db/table_cache.cc
+@@ -164,6 +164,7 @@ Status TableCache::GetTableReader(
+ }
+ 
+ Cache::Handle* TableCache::Lookup(Cache* cache, uint64_t file_number) {
++  // NOTE: sharing same Cache with BlobFileCache
+   Slice key = GetSliceForFileNumber(&file_number);
+   return cache->Lookup(key);
+ }
+@@ -179,6 +180,7 @@ Status TableCache::FindTable(
+     size_t max_file_size_for_l0_meta_pin, Temperature file_temperature) {
+   PERF_TIMER_GUARD_WITH_CLOCK(find_table_nanos, ioptions_.clock);
+   uint64_t number = file_meta.fd.GetNumber();
++  // NOTE: sharing same Cache with BlobFileCache
+   Slice key = GetSliceForFileNumber(&number);
+   *handle = cache_.Lookup(key);
+   TEST_SYNC_POINT_CALLBACK("TableCache::FindTable:0",
+diff --git a/db/version_builder.cc b/db/version_builder.cc
+index ed8ab8214..c98f53f42 100644
+--- a/db/version_builder.cc
++++ b/db/version_builder.cc
+@@ -24,6 +24,7 @@
+ #include <vector>
+ 
+ #include "cache/cache_reservation_manager.h"
++#include "db/blob/blob_file_cache.h"
+ #include "db/blob/blob_file_meta.h"
+ #include "db/dbformat.h"
+ #include "db/internal_stats.h"
+@@ -744,12 +745,9 @@ class VersionBuilder::Rep {
+       return Status::Corruption("VersionBuilder", oss.str());
+     }
+ 
+-    // Note: we use C++11 for now but in C++14, this could be done in a more
+-    // elegant way using generalized lambda capture.
+-    VersionSet* const vs = version_set_;
+-    const ImmutableCFOptions* const ioptions = ioptions_;
+-
+-    auto deleter = [vs, ioptions](SharedBlobFileMetaData* shared_meta) {
++    auto deleter = [vs = version_set_, ioptions = ioptions_,
++                    bc = cfd_ ? cfd_->blob_file_cache()
++                              : nullptr](SharedBlobFileMetaData* shared_meta) {
+       if (vs) {
+         assert(ioptions);
+         assert(!ioptions->cf_paths.empty());
+@@ -758,6 +756,9 @@ class VersionBuilder::Rep {
+         vs->AddObsoleteBlobFile(shared_meta->GetBlobFileNumber(),
+                                 ioptions->cf_paths.front().path);
+       }
++      if (bc) {
++        bc->Evict(shared_meta->GetBlobFileNumber());
++      }
+ 
+       delete shared_meta;
+     };
+@@ -766,7 +767,7 @@ class VersionBuilder::Rep {
+         blob_file_number, blob_file_addition.GetTotalBlobCount(),
+         blob_file_addition.GetTotalBlobBytes(),
+         blob_file_addition.GetChecksumMethod(),
+-        blob_file_addition.GetChecksumValue(), deleter);
++        blob_file_addition.GetChecksumValue(), std::move(deleter));
+ 
+     mutable_blob_file_metas_.emplace(
+         blob_file_number, MutableBlobFileMetaData(std::move(shared_meta)));
+diff --git a/db/version_set.h b/db/version_set.h
+index 9336782b1..024f869e7 100644
+--- a/db/version_set.h
++++ b/db/version_set.h
+@@ -1514,7 +1514,6 @@ class VersionSet {
+   void GetLiveFilesMetaData(std::vector<LiveFileMetaData>* metadata);
+ 
+   void AddObsoleteBlobFile(uint64_t blob_file_number, std::string path) {
+-    // TODO: Erase file from BlobFileCache?
+     obsolete_blob_files_.emplace_back(blob_file_number, std::move(path));
+   }
+ 
+diff --git a/include/rocksdb/version.h b/include/rocksdb/version.h
+index 2a19796b8..0afa2cab1 100644
+--- a/include/rocksdb/version.h
++++ b/include/rocksdb/version.h
+@@ -13,7 +13,7 @@
+ // minor or major version number planned for release.
+ #define ROCKSDB_MAJOR 9
+ #define ROCKSDB_MINOR 7
+-#define ROCKSDB_PATCH 3
++#define ROCKSDB_PATCH 4
+ 
+ // Do not use these. We made the mistake of declaring macros starting with
+ // double underscore. Now we have to live with our choice. We'll deprecate these
+diff --git a/port/port.h b/port/port.h
+index 13aa56d47..141716e5b 100644
+--- a/port/port.h
++++ b/port/port.h
+@@ -19,3 +19,19 @@
+ #elif defined(OS_WIN)
+ #include "port/win/port_win.h"
+ #endif
++
++#ifdef OS_LINUX
++// A temporary hook into long-running RocksDB threads to support modifying their
++// priority etc. This should become a public API hook once the requirements
++// are better understood.
++extern "C" void RocksDbThreadYield() __attribute__((__weak__));
++#define ROCKSDB_THREAD_YIELD_HOOK() \
++  {                                 \
++    if (RocksDbThreadYield) {       \
++      RocksDbThreadYield();         \
++    }                               \
++  }
++#else
++#define ROCKSDB_THREAD_YIELD_HOOK() \
++  {}
++#endif

external/rocksdb/patches/9.x.x-0001-exclude-thirdparty.patch

@@ -0,0 +1,30 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 93b884d..b715cb6 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -106,14 +106,9 @@ endif()
+ include(CMakeDependentOption)
+
+ if(MSVC)
+-  option(WITH_GFLAGS "build with GFlags" OFF)
+   option(WITH_XPRESS "build with windows built in compression" OFF)
+-  option(ROCKSDB_SKIP_THIRDPARTY "skip thirdparty.inc" OFF)
+-
+-  if(NOT ROCKSDB_SKIP_THIRDPARTY)
+-    include(${CMAKE_CURRENT_SOURCE_DIR}/thirdparty.inc)
+-  endif()
+-else()
++endif()
++if(TRUE)
+   if(CMAKE_SYSTEM_NAME MATCHES "FreeBSD" AND NOT CMAKE_SYSTEM_NAME MATCHES "kFreeBSD")
+     # FreeBSD has jemalloc as default malloc
+     # but it does not have all the jemalloc files in include/...
+@@ -126,7 +121,7 @@ else()
+     endif()
+   endif()
+
+-  if(MINGW)
++  if(MSVC OR MINGW)
+     option(WITH_GFLAGS "build with GFlags" OFF)
+   else()
+     option(WITH_GFLAGS "build with GFlags" ON)

hook/hookapi.h

@@ -45,8 +45,8 @@
 
 #include "error.h"
 #include "extern.h"
-#include "sfcodes.h"
 #include "macro.h"
+#include "sfcodes.h"
 #include "tts.h"
 
 #endif

hook/sfcodes.h

@@ -9,6 +9,7 @@
 #define sfUNLModifyDisabling ((16U << 16U) + 17U)
 #define sfHookResult ((16U << 16U) + 18U)
 #define sfWasLockingChainSend ((16U << 16U) + 19U)
+#define sfWithdrawalPolicy ((16U << 16U) + 20U)
 #define sfLedgerEntryType ((1U << 16U) + 1U)
 #define sfTransactionType ((1U << 16U) + 2U)
 #define sfSignerWeight ((1U << 16U) + 3U)
@@ -72,6 +73,7 @@
 #define sfLockCount ((2U << 16U) + 49U)
 #define sfFirstNFTokenSequence ((2U << 16U) + 50U)
 #define sfOracleDocumentID ((2U << 16U) + 51U)
+#define sfPermissionValue ((2U << 16U) + 52U)
 #define sfStartTime ((2U << 16U) + 93U)
 #define sfRepeatCount ((2U << 16U) + 94U)
 #define sfDelaySeconds ((2U << 16U) + 95U)
@@ -115,6 +117,7 @@
 #define sfTakerGetsCurrency ((17U << 16U) + 3U)
 #define sfTakerGetsIssuer ((17U << 16U) + 4U)
 #define sfMPTokenIssuanceID ((21U << 16U) + 1U)
+#define sfShareMPTID ((21U << 16U) + 2U)
 #define sfLedgerHash ((5U << 16U) + 1U)
 #define sfParentHash ((5U << 16U) + 2U)
 #define sfTransactionHash ((5U << 16U) + 3U)
@@ -152,6 +155,7 @@
 #define sfEscrowID ((5U << 16U) + 35U)
 #define sfURITokenID ((5U << 16U) + 36U)
 #define sfDomainID ((5U << 16U) + 37U)
+#define sfVaultID ((5U << 16U) + 38U)
 #define sfHookOnOutgoing ((5U << 16U) + 93U)
 #define sfHookOnIncoming ((5U << 16U) + 94U)
 #define sfCron ((5U << 16U) + 95U)
@@ -160,6 +164,10 @@
 #define sfGovernanceMarks ((5U << 16U) + 98U)
 #define sfGovernanceFlags ((5U << 16U) + 99U)
 #define sfNumber ((9U << 16U) + 1U)
+#define sfAssetsAvailable ((9U << 16U) + 2U)
+#define sfAssetsMaximum ((9U << 16U) + 3U)
+#define sfAssetsTotal ((9U << 16U) + 4U)
+#define sfLossUnrealized ((9U << 16U) + 5U)
 #define sfAmount ((6U << 16U) + 1U)
 #define sfBalance ((6U << 16U) + 2U)
 #define sfLimitAmount ((6U << 16U) + 3U)
@@ -232,6 +240,7 @@
 #define sfNFTokenMinter ((8U << 16U) + 9U)
 #define sfEmitCallback ((8U << 16U) + 10U)
 #define sfHolder ((8U << 16U) + 11U)
+#define sfDelegate ((8U << 16U) + 12U)
 #define sfHookAccount ((8U << 16U) + 16U)
 #define sfOtherChainSource ((8U << 16U) + 18U)
 #define sfOtherChainDestination ((8U << 16U) + 19U)
@@ -269,6 +278,7 @@
 #define sfNFToken ((14U << 16U) + 12U)
 #define sfEmitDetails ((14U << 16U) + 13U)
 #define sfHook ((14U << 16U) + 14U)
+#define sfPermission ((14U << 16U) + 15U)
 #define sfSigner ((14U << 16U) + 16U)
 #define sfMajority ((14U << 16U) + 18U)
 #define sfDisabledValidator ((14U << 16U) + 19U)
@@ -315,6 +325,7 @@
 #define sfAuthorizeCredentials ((15U << 16U) + 26U)
 #define sfUnauthorizeCredentials ((15U << 16U) + 27U)
 #define sfAcceptedCredentials ((15U << 16U) + 28U)
+#define sfPermissions ((15U << 16U) + 29U)
 #define sfAmounts ((15U << 16U) + 92U)
 #define sfHookEmissions ((15U << 16U) + 93U)
 #define sfImportVLKeys ((15U << 16U) + 94U)

hook/tts.h

@@ -61,6 +61,13 @@
 #define ttNFTOKEN_MODIFY 70
 #define ttPERMISSIONED_DOMAIN_SET 71
 #define ttPERMISSIONED_DOMAIN_DELETE 72
+#define ttDELEGATE_SET 73
+#define ttVAULT_CREATE 74
+#define ttVAULT_SET 75
+#define ttVAULT_DELETE 76
+#define ttVAULT_DEPOSIT 77
+#define ttVAULT_WITHDRAW 78
+#define ttVAULT_CLAWBACK 79
 #define ttCRON 92
 #define ttCRON_SET 93
 #define ttREMARKS_SET 94

include/xrpl/basics/BasicConfig.h

@@ -27,7 +27,6 @@
 
 #include <algorithm>
 #include <optional>
-#include <ostream>
 #include <string>
 #include <unordered_map>
 #include <vector>
@@ -368,7 +367,7 @@ get(Section const& section,
 }
 
 inline std::string
-get(Section const& section, std::string const& name, const char* defaultValue)
+get(Section const& section, std::string const& name, char const* defaultValue)
 {
     try
     {

include/xrpl/basics/Buffer.h

@@ -22,10 +22,9 @@
 
 #include <xrpl/basics/Slice.h>
 #include <xrpl/beast/utility/instrumentation.h>
+
 #include <cstdint>
 #include <cstring>
-#include <memory>
-#include <utility>
 
 namespace ripple {
 

include/xrpl/basics/CompressionAlgorithms.h

@@ -21,9 +21,11 @@
 #define RIPPLED_COMPRESSIONALGORITHMS_H_INCLUDED
 
 #include <xrpl/basics/contract.h>
+
+#include <lz4.h>
+
 #include <algorithm>
 #include <cstdint>
-#include <lz4.h>
 #include <stdexcept>
 #include <vector>
 
@@ -53,7 +55,7 @@ lz4Compress(void const* in, std::size_t inSize, BufferFactory&& bf)
     auto compressed = bf(outCapacity);
 
     auto compressedSize = LZ4_compress_default(
-        reinterpret_cast<const char*>(in),
+        reinterpret_cast<char const*>(in),
         reinterpret_cast<char*>(compressed),
         inSize,
         outCapacity);
@@ -87,7 +89,7 @@ lz4Decompress(
         Throw<std::runtime_error>("lz4Decompress: integer overflow (output)");
 
     if (LZ4_decompress_safe(
-            reinterpret_cast<const char*>(in),
+            reinterpret_cast<char const*>(in),
             reinterpret_cast<char*>(decompressed),
             inSize,
             decompressedSize) != decompressedSize)

include/xrpl/basics/CountedObject.h

@@ -21,6 +21,7 @@
 #define RIPPLE_BASICS_COUNTEDOBJECT_H_INCLUDED
 
 #include <xrpl/beast/type_name.h>
+
 #include <atomic>
 #include <string>
 #include <utility>

include/xrpl/basics/Expected.h

@@ -24,9 +24,7 @@
 
 #include <boost/outcome.hpp>
 
-#include <concepts>
 #include <stdexcept>
-#include <type_traits>
 
 namespace ripple {
 
@@ -95,7 +93,7 @@ public:
     {
     }
 
-    constexpr const E&
+    constexpr E const&
     value() const&
     {
         return val_;
@@ -113,7 +111,7 @@ public:
         return std::move(val_);
     }
 
-    constexpr const E&&
+    constexpr E const&&
     value() const&&
     {
         return std::move(val_);

include/xrpl/basics/IntrusivePointer.h

@@ -0,0 +1,515 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2023 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_BASICS_INTRUSIVEPOINTER_H_INCLUDED
+#define RIPPLE_BASICS_INTRUSIVEPOINTER_H_INCLUDED
+
+#include <concepts>
+#include <cstdint>
+#include <type_traits>
+#include <utility>
+
+namespace ripple {
+
+//------------------------------------------------------------------------------
+
+/** Tag to create an intrusive pointer from another intrusive pointer by using a
+    static cast. This is useful to create an intrusive pointer to a derived
+    class from an intrusive pointer to a base class.
+*/
+struct StaticCastTagSharedIntrusive
+{
+};
+
+/** Tag to create an intrusive pointer from another intrusive pointer by using a
+    dynamic cast. This is useful to create an intrusive pointer to a derived
+    class from an intrusive pointer to a base class. If the cast fails an empty
+    (null) intrusive pointer is created.
+*/
+struct DynamicCastTagSharedIntrusive
+{
+};
+
+/** When creating or adopting a raw pointer, controls whether the strong count
+    is incremented or not. Use this tag to increment the strong count.
+*/
+struct SharedIntrusiveAdoptIncrementStrongTag
+{
+};
+
+/** When creating or adopting a raw pointer, controls whether the strong count
+    is incremented or not. Use this tag to leave the strong count unchanged.
+*/
+struct SharedIntrusiveAdoptNoIncrementTag
+{
+};
+
+//------------------------------------------------------------------------------
+//
+
+template <class T>
+concept CAdoptTag = std::is_same_v<T, SharedIntrusiveAdoptIncrementStrongTag> ||
+    std::is_same_v<T, SharedIntrusiveAdoptNoIncrementTag>;
+
+//------------------------------------------------------------------------------
+
+/** A shared intrusive pointer class that supports weak pointers.
+
+    This is meant to be used for SHAMapInnerNodes, but may be useful for other
+    cases. Since the reference counts are stored on the pointee, the pointee is
+    not destroyed until both the strong _and_ weak pointer counts go to zero.
+    When the strong pointer count goes to zero, the "partialDestructor" is
+    called. This can be used to destroy as much of the object as possible while
+    still retaining the reference counts. For example, for SHAMapInnerNodes the
+    children may be reset in that function. Note that std::shared_poiner WILL
+    run the destructor when the strong count reaches zero, but may not free the
+    memory used by the object until the weak count reaches zero. In rippled, we
+    typically allocate shared pointers with the `make_shared` function. When
+    that is used, the memory is not reclaimed until the weak count reaches zero.
+*/
+template <class T>
+class SharedIntrusive
+{
+public:
+    SharedIntrusive() = default;
+
+    template <CAdoptTag TAdoptTag>
+    SharedIntrusive(T* p, TAdoptTag) noexcept;
+
+    SharedIntrusive(SharedIntrusive const& rhs);
+
+    template <class TT>
+    // TODO: convertible_to isn't quite right. That include a static castable.
+    // Find the right concept.
+        requires std::convertible_to<TT*, T*>
+    SharedIntrusive(SharedIntrusive<TT> const& rhs);
+
+    SharedIntrusive(SharedIntrusive&& rhs);
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedIntrusive(SharedIntrusive<TT>&& rhs);
+
+    SharedIntrusive&
+    operator=(SharedIntrusive const& rhs);
+
+    bool
+    operator!=(std::nullptr_t) const;
+
+    bool
+    operator==(std::nullptr_t) const;
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedIntrusive&
+    operator=(SharedIntrusive<TT> const& rhs);
+
+    SharedIntrusive&
+    operator=(SharedIntrusive&& rhs);
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedIntrusive&
+    operator=(SharedIntrusive<TT>&& rhs);
+
+    /** Adopt the raw pointer. The strong reference may or may not be
+        incremented, depending on the TAdoptTag
+     */
+    template <CAdoptTag TAdoptTag = SharedIntrusiveAdoptIncrementStrongTag>
+    void
+    adopt(T* p);
+
+    ~SharedIntrusive();
+
+    /** Create a new SharedIntrusive by statically casting the pointer
+        controlled by the rhs param.
+    */
+    template <class TT>
+    SharedIntrusive(
+        StaticCastTagSharedIntrusive,
+        SharedIntrusive<TT> const& rhs);
+
+    /** Create a new SharedIntrusive by statically casting the pointer
+       controlled by the rhs param.
+    */
+    template <class TT>
+    SharedIntrusive(StaticCastTagSharedIntrusive, SharedIntrusive<TT>&& rhs);
+
+    /** Create a new SharedIntrusive by dynamically casting the pointer
+       controlled by the rhs param.
+    */
+    template <class TT>
+    SharedIntrusive(
+        DynamicCastTagSharedIntrusive,
+        SharedIntrusive<TT> const& rhs);
+
+    /** Create a new SharedIntrusive by dynamically casting the pointer
+       controlled by the rhs param.
+    */
+    template <class TT>
+    SharedIntrusive(DynamicCastTagSharedIntrusive, SharedIntrusive<TT>&& rhs);
+
+    T&
+    operator*() const noexcept;
+
+    T*
+    operator->() const noexcept;
+
+    explicit
+    operator bool() const noexcept;
+
+    /** Set the pointer to null, decrement the strong count, and run the
+        appropriate release action.
+      */
+    void
+    reset();
+
+    /** Get the raw pointer */
+    T*
+    get() const;
+
+    /** Return the strong count */
+    std::size_t
+    use_count() const;
+
+    template <class TT, class... Args>
+    friend SharedIntrusive<TT>
+    make_SharedIntrusive(Args&&... args);
+
+    template <class TT>
+    friend class SharedIntrusive;
+
+    template <class TT>
+    friend class SharedWeakUnion;
+
+    template <class TT>
+    friend class WeakIntrusive;
+
+private:
+    /** Return the raw pointer held by this object. */
+    T*
+    unsafeGetRawPtr() const;
+
+    /** Exchange the current raw pointer held by this object with the given
+        pointer. Decrement the strong count of the raw pointer previously held
+        by this object and run the appropriate release action.
+     */
+    void
+    unsafeReleaseAndStore(T* next);
+
+    /** Set the raw pointer directly. This is wrapped in a function so the class
+        can support both atomic and non-atomic pointers in a future patch.
+     */
+    void
+    unsafeSetRawPtr(T* p);
+
+    /** Exchange the raw pointer directly.
+        This sets the raw pointer to the given value and returns the previous
+        value. This is wrapped in a function so the class can support both
+        atomic and non-atomic pointers in a future patch.
+     */
+    T*
+    unsafeExchange(T* p);
+
+    /** pointer to the type with an intrusive count */
+    T* ptr_{nullptr};
+};
+
+//------------------------------------------------------------------------------
+
+/** A weak intrusive pointer class for the SharedIntrusive pointer class.
+
+Note that this weak pointer class asks differently from normal weak pointer
+classes. When the strong pointer count goes to zero, the "partialDestructor"
+is called. See the comment on SharedIntrusive for a fuller explanation.
+*/
+template <class T>
+class WeakIntrusive
+{
+public:
+    WeakIntrusive() = default;
+
+    WeakIntrusive(WeakIntrusive const& rhs);
+
+    WeakIntrusive(WeakIntrusive&& rhs);
+
+    WeakIntrusive(SharedIntrusive<T> const& rhs);
+
+    // There is no move constructor from a strong intrusive ptr because
+    // moving would be move expensive than copying in this case (the strong
+    // ref would need to be decremented)
+    WeakIntrusive(SharedIntrusive<T> const&& rhs) = delete;
+
+    // Since there are no current use cases for copy assignment in
+    // WeakIntrusive, we delete this operator to simplify the implementation. If
+    // a need arises in the future, we can reintroduce it with proper
+    // consideration."
+    WeakIntrusive&
+    operator=(WeakIntrusive const&) = delete;
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    WeakIntrusive&
+    operator=(SharedIntrusive<TT> const& rhs);
+
+    /** Adopt the raw pointer and increment the weak count. */
+    void
+    adopt(T* ptr);
+
+    ~WeakIntrusive();
+
+    /** Get a strong pointer from the weak pointer, if possible. This will
+       only return a seated pointer if the strong count on the raw pointer
+       is non-zero before locking.
+     */
+    SharedIntrusive<T>
+    lock() const;
+
+    /** Return true if the strong count is zero. */
+    bool
+    expired() const;
+
+    /** Set the pointer to null and decrement the weak count.
+
+    Note: This may run the destructor if the strong count is zero.
+    */
+    void
+    reset();
+
+private:
+    T* ptr_ = nullptr;
+
+    /** Decrement the weak count. This does _not_ set the raw pointer to
+    null.
+
+    Note: This may run the destructor if the strong count is zero.
+    */
+    void
+    unsafeReleaseNoStore();
+};
+
+//------------------------------------------------------------------------------
+
+/** A combination of a strong and a weak intrusive pointer stored in the
+    space of a single pointer.
+
+    This class is similar to a `std::variant<SharedIntrusive,WeakIntrusive>`
+    with some optimizations. In particular, it uses a low-order bit to
+    determine if the raw pointer represents a strong pointer or a weak
+    pointer. It can also be quickly switched between its strong pointer and
+    weak pointer representations. This class is useful for storing intrusive
+    pointers in tagged caches.
+  */
+
+template <class T>
+class SharedWeakUnion
+{
+    // Tagged pointer. Low bit determines if this is a strong or a weak
+    // pointer. The low bit must be masked to zero when converting back to a
+    // pointer. If the low bit is '1', this is a weak pointer.
+    static_assert(
+        alignof(T) >= 2,
+        "Bad alignment: Combo pointer requires low bit to be zero");
+
+public:
+    SharedWeakUnion() = default;
+
+    SharedWeakUnion(SharedWeakUnion const& rhs);
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedWeakUnion(SharedIntrusive<TT> const& rhs);
+
+    SharedWeakUnion(SharedWeakUnion&& rhs);
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedWeakUnion(SharedIntrusive<TT>&& rhs);
+
+    SharedWeakUnion&
+    operator=(SharedWeakUnion const& rhs);
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedWeakUnion&
+    operator=(SharedIntrusive<TT> const& rhs);
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedWeakUnion&
+    operator=(SharedIntrusive<TT>&& rhs);
+
+    ~SharedWeakUnion();
+
+    /** Return a strong pointer if this is already a strong pointer (i.e.
+       don't lock the weak pointer. Use the `lock` method if that's what's
+       needed)
+     */
+    SharedIntrusive<T>
+    getStrong() const;
+
+    /** Return true if this is a strong pointer and the strong pointer is
+        seated.
+     */
+    explicit
+    operator bool() const noexcept;
+
+    /** Set the pointer to null, decrement the appropriate ref count, and
+       run the appropriate release action.
+     */
+    void
+    reset();
+
+    /** If this is a strong pointer, return the raw pointer. Otherwise
+       return null.
+     */
+    T*
+    get() const;
+
+    /** If this is a strong pointer, return the strong count. Otherwise
+     * return 0
+     */
+    std::size_t
+    use_count() const;
+
+    /** Return true if there is a non-zero strong count. */
+    bool
+    expired() const;
+
+    /** If this is a strong pointer, return the strong pointer. Otherwise
+        attempt to lock the weak pointer.
+     */
+    SharedIntrusive<T>
+    lock() const;
+
+    /** Return true is this represents a strong pointer. */
+    bool
+    isStrong() const;
+
+    /** Return true is this represents a weak pointer. */
+    bool
+    isWeak() const;
+
+    /** If this is a weak pointer, attempt to convert it to a strong
+       pointer.
+
+        @return true if successfully converted to a strong pointer (or was
+                already a strong pointer). Otherwise false.
+      */
+    bool
+    convertToStrong();
+
+    /** If this is a strong pointer, attempt to convert it to a weak
+       pointer.
+
+        @return false if the pointer is null. Otherwise return true.
+      */
+    bool
+    convertToWeak();
+
+private:
+    // Tagged pointer. Low bit determines if this is a strong or a weak
+    // pointer. The low bit must be masked to zero when converting back to a
+    // pointer. If the low bit is '1', this is a weak pointer.
+    std::uintptr_t tp_{0};
+    static constexpr std::uintptr_t tagMask = 1;
+    static constexpr std::uintptr_t ptrMask = ~tagMask;
+
+private:
+    /** Return the raw pointer held by this object.
+     */
+    T*
+    unsafeGetRawPtr() const;
+
+    enum class RefStrength { strong, weak };
+    /** Set the raw pointer and tag bit directly.
+     */
+    void
+    unsafeSetRawPtr(T* p, RefStrength rs);
+
+    /** Set the raw pointer and tag bit to all zeros (strong null pointer).
+     */
+    void unsafeSetRawPtr(std::nullptr_t);
+
+    /** Decrement the appropriate ref count, and run the appropriate release
+        action. Note: this does _not_ set the raw pointer to null.
+     */
+    void
+    unsafeReleaseNoStore();
+};
+
+//------------------------------------------------------------------------------
+
+/** Create a shared intrusive pointer.
+
+    Note: unlike std::shared_ptr, where there is an advantage of allocating
+    the pointer and control block together, there is no benefit for intrusive
+    pointers.
+*/
+template <class TT, class... Args>
+SharedIntrusive<TT>
+make_SharedIntrusive(Args&&... args)
+{
+    auto p = new TT(std::forward<Args>(args)...);
+
+    static_assert(
+        noexcept(SharedIntrusive<TT>(
+            std::declval<TT*>(),
+            std::declval<SharedIntrusiveAdoptNoIncrementTag>())),
+        "SharedIntrusive constructor should not throw or this can leak "
+        "memory");
+
+    return SharedIntrusive<TT>(p, SharedIntrusiveAdoptNoIncrementTag{});
+}
+
+//------------------------------------------------------------------------------
+
+namespace intr_ptr {
+template <class T>
+using SharedPtr = SharedIntrusive<T>;
+
+template <class T>
+using WeakPtr = WeakIntrusive<T>;
+
+template <class T>
+using SharedWeakUnionPtr = SharedWeakUnion<T>;
+
+template <class T, class... A>
+SharedPtr<T>
+make_shared(A&&... args)
+{
+    return make_SharedIntrusive<T>(std::forward<A>(args)...);
+}
+
+template <class T, class TT>
+SharedPtr<T>
+static_pointer_cast(TT const& v)
+{
+    return SharedPtr<T>(StaticCastTagSharedIntrusive{}, v);
+}
+
+template <class T, class TT>
+SharedPtr<T>
+dynamic_pointer_cast(TT const& v)
+{
+    return SharedPtr<T>(DynamicCastTagSharedIntrusive{}, v);
+}
+}  // namespace intr_ptr
+}  // namespace ripple
+#endif

include/xrpl/basics/IntrusivePointer.ipp

@@ -0,0 +1,740 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2023 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_BASICS_INTRUSIVEPOINTER_IPP_INCLUDED
+#define RIPPLE_BASICS_INTRUSIVEPOINTER_IPP_INCLUDED
+
+#include <xrpl/basics/IntrusivePointer.h>
+#include <xrpl/basics/IntrusiveRefCounts.h>
+
+#include <utility>
+
+namespace ripple {
+
+template <class T>
+template <CAdoptTag TAdoptTag>
+SharedIntrusive<T>::SharedIntrusive(T* p, TAdoptTag) noexcept : ptr_{p}
+{
+    if constexpr (std::is_same_v<
+                      TAdoptTag,
+                      SharedIntrusiveAdoptIncrementStrongTag>)
+    {
+        if (p)
+            p->addStrongRef();
+    }
+}
+
+template <class T>
+SharedIntrusive<T>::SharedIntrusive(SharedIntrusive const& rhs)
+    : ptr_{[&] {
+        auto p = rhs.unsafeGetRawPtr();
+        if (p)
+            p->addStrongRef();
+        return p;
+    }()}
+{
+}
+
+template <class T>
+template <class TT>
+    requires std::convertible_to<TT*, T*>
+SharedIntrusive<T>::SharedIntrusive(SharedIntrusive<TT> const& rhs)
+    : ptr_{[&] {
+        auto p = rhs.unsafeGetRawPtr();
+        if (p)
+            p->addStrongRef();
+        return p;
+    }()}
+{
+}
+
+template <class T>
+SharedIntrusive<T>::SharedIntrusive(SharedIntrusive&& rhs)
+    : ptr_{rhs.unsafeExchange(nullptr)}
+{
+}
+
+template <class T>
+template <class TT>
+    requires std::convertible_to<TT*, T*>
+SharedIntrusive<T>::SharedIntrusive(SharedIntrusive<TT>&& rhs)
+    : ptr_{rhs.unsafeExchange(nullptr)}
+{
+}
+template <class T>
+SharedIntrusive<T>&
+SharedIntrusive<T>::operator=(SharedIntrusive const& rhs)
+{
+    if (this == &rhs)
+        return *this;
+    auto p = rhs.unsafeGetRawPtr();
+    if (p)
+        p->addStrongRef();
+    unsafeReleaseAndStore(p);
+    return *this;
+}
+
+template <class T>
+template <class TT>
+// clang-format off
+requires std::convertible_to<TT*, T*>
+// clang-format on
+SharedIntrusive<T>&
+SharedIntrusive<T>::operator=(SharedIntrusive<TT> const& rhs)
+{
+    if constexpr (std::is_same_v<T, TT>)
+    {
+        // This case should never be hit. The operator above will run instead.
+        // (The normal operator= is needed or it will be marked `deleted`)
+        if (this == &rhs)
+            return *this;
+    }
+    auto p = rhs.unsafeGetRawPtr();
+    if (p)
+        p->addStrongRef();
+    unsafeReleaseAndStore(p);
+    return *this;
+}
+
+template <class T>
+SharedIntrusive<T>&
+SharedIntrusive<T>::operator=(SharedIntrusive&& rhs)
+{
+    if (this == &rhs)
+        return *this;
+
+    unsafeReleaseAndStore(rhs.unsafeExchange(nullptr));
+    return *this;
+}
+
+template <class T>
+template <class TT>
+// clang-format off
+requires std::convertible_to<TT*, T*>
+// clang-format on
+SharedIntrusive<T>&
+SharedIntrusive<T>::operator=(SharedIntrusive<TT>&& rhs)
+{
+    static_assert(
+        !std::is_same_v<T, TT>,
+        "This overload should not be instantiated for T == TT");
+
+    unsafeReleaseAndStore(rhs.unsafeExchange(nullptr));
+    return *this;
+}
+
+template <class T>
+bool
+SharedIntrusive<T>::operator!=(std::nullptr_t) const
+{
+    return this->get() != nullptr;
+}
+
+template <class T>
+bool
+SharedIntrusive<T>::operator==(std::nullptr_t) const
+{
+    return this->get() == nullptr;
+}
+
+template <class T>
+template <CAdoptTag TAdoptTag>
+void
+SharedIntrusive<T>::adopt(T* p)
+{
+    if constexpr (std::is_same_v<
+                      TAdoptTag,
+                      SharedIntrusiveAdoptIncrementStrongTag>)
+    {
+        if (p)
+            p->addStrongRef();
+    }
+    unsafeReleaseAndStore(p);
+}
+
+template <class T>
+SharedIntrusive<T>::~SharedIntrusive()
+{
+    unsafeReleaseAndStore(nullptr);
+};
+
+template <class T>
+template <class TT>
+SharedIntrusive<T>::SharedIntrusive(
+    StaticCastTagSharedIntrusive,
+    SharedIntrusive<TT> const& rhs)
+    : ptr_{[&] {
+        auto p = static_cast<T*>(rhs.unsafeGetRawPtr());
+        if (p)
+            p->addStrongRef();
+        return p;
+    }()}
+{
+}
+
+template <class T>
+template <class TT>
+SharedIntrusive<T>::SharedIntrusive(
+    StaticCastTagSharedIntrusive,
+    SharedIntrusive<TT>&& rhs)
+    : ptr_{static_cast<T*>(rhs.unsafeExchange(nullptr))}
+{
+}
+
+template <class T>
+template <class TT>
+SharedIntrusive<T>::SharedIntrusive(
+    DynamicCastTagSharedIntrusive,
+    SharedIntrusive<TT> const& rhs)
+    : ptr_{[&] {
+        auto p = dynamic_cast<T*>(rhs.unsafeGetRawPtr());
+        if (p)
+            p->addStrongRef();
+        return p;
+    }()}
+{
+}
+
+template <class T>
+template <class TT>
+SharedIntrusive<T>::SharedIntrusive(
+    DynamicCastTagSharedIntrusive,
+    SharedIntrusive<TT>&& rhs)
+{
+    // This can be simplified without the `exchange`, but the `exchange` is kept
+    // in anticipation of supporting atomic operations.
+    auto toSet = rhs.unsafeExchange(nullptr);
+    if (toSet)
+    {
+        ptr_ = dynamic_cast<T*>(toSet);
+        if (!ptr_)
+            // need to set the pointer back or will leak
+            rhs.unsafeExchange(toSet);
+    }
+}
+
+template <class T>
+T&
+SharedIntrusive<T>::operator*() const noexcept
+{
+    return *unsafeGetRawPtr();
+}
+
+template <class T>
+T*
+SharedIntrusive<T>::operator->() const noexcept
+{
+    return unsafeGetRawPtr();
+}
+
+template <class T>
+SharedIntrusive<T>::operator bool() const noexcept
+{
+    return bool(unsafeGetRawPtr());
+}
+
+template <class T>
+void
+SharedIntrusive<T>::reset()
+{
+    unsafeReleaseAndStore(nullptr);
+}
+
+template <class T>
+T*
+SharedIntrusive<T>::get() const
+{
+    return unsafeGetRawPtr();
+}
+
+template <class T>
+std::size_t
+SharedIntrusive<T>::use_count() const
+{
+    if (auto p = unsafeGetRawPtr())
+        return p->use_count();
+    return 0;
+}
+
+template <class T>
+T*
+SharedIntrusive<T>::unsafeGetRawPtr() const
+{
+    return ptr_;
+}
+
+template <class T>
+void
+SharedIntrusive<T>::unsafeSetRawPtr(T* p)
+{
+    ptr_ = p;
+}
+
+template <class T>
+T*
+SharedIntrusive<T>::unsafeExchange(T* p)
+{
+    return std::exchange(ptr_, p);
+}
+
+template <class T>
+void
+SharedIntrusive<T>::unsafeReleaseAndStore(T* next)
+{
+    auto prev = unsafeExchange(next);
+    if (!prev)
+        return;
+
+    using enum ReleaseStrongRefAction;
+    auto action = prev->releaseStrongRef();
+    switch (action)
+    {
+        case noop:
+            break;
+        case destroy:
+            delete prev;
+            break;
+        case partialDestroy:
+            prev->partialDestructor();
+            partialDestructorFinished(&prev);
+            // prev is null and may no longer be used
+            break;
+    }
+}
+
+//------------------------------------------------------------------------------
+
+template <class T>
+WeakIntrusive<T>::WeakIntrusive(WeakIntrusive const& rhs) : ptr_{rhs.ptr_}
+{
+    if (ptr_)
+        ptr_->addWeakRef();
+}
+
+template <class T>
+WeakIntrusive<T>::WeakIntrusive(WeakIntrusive&& rhs) : ptr_{rhs.ptr_}
+{
+    rhs.ptr_ = nullptr;
+}
+
+template <class T>
+WeakIntrusive<T>::WeakIntrusive(SharedIntrusive<T> const& rhs)
+    : ptr_{rhs.unsafeGetRawPtr()}
+{
+    if (ptr_)
+        ptr_->addWeakRef();
+}
+
+template <class T>
+template <class TT>
+// clang-format off
+requires std::convertible_to<TT*, T*>
+// clang-format on
+WeakIntrusive<T>&
+WeakIntrusive<T>::operator=(SharedIntrusive<TT> const& rhs)
+{
+    unsafeReleaseNoStore();
+    auto p = rhs.unsafeGetRawPtr();
+    if (p)
+        p->addWeakRef();
+    return *this;
+}
+
+template <class T>
+void
+WeakIntrusive<T>::adopt(T* ptr)
+{
+    unsafeReleaseNoStore();
+    if (ptr)
+        ptr->addWeakRef();
+    ptr_ = ptr;
+}
+
+template <class T>
+WeakIntrusive<T>::~WeakIntrusive()
+{
+    unsafeReleaseNoStore();
+}
+
+template <class T>
+SharedIntrusive<T>
+WeakIntrusive<T>::lock() const
+{
+    if (ptr_ && ptr_->checkoutStrongRefFromWeak())
+    {
+        return SharedIntrusive<T>{ptr_, SharedIntrusiveAdoptNoIncrementTag{}};
+    }
+    return {};
+}
+
+template <class T>
+bool
+WeakIntrusive<T>::expired() const
+{
+    return (!ptr_ || ptr_->expired());
+}
+
+template <class T>
+void
+WeakIntrusive<T>::reset()
+{
+    unsafeReleaseNoStore();
+    ptr_ = nullptr;
+}
+
+template <class T>
+void
+WeakIntrusive<T>::unsafeReleaseNoStore()
+{
+    if (!ptr_)
+        return;
+
+    using enum ReleaseWeakRefAction;
+    auto action = ptr_->releaseWeakRef();
+    switch (action)
+    {
+        case noop:
+            break;
+        case destroy:
+            delete ptr_;
+            break;
+    }
+}
+
+//------------------------------------------------------------------------------
+
+template <class T>
+SharedWeakUnion<T>::SharedWeakUnion(SharedWeakUnion const& rhs) : tp_{rhs.tp_}
+{
+    auto p = rhs.unsafeGetRawPtr();
+    if (!p)
+        return;
+
+    if (rhs.isStrong())
+        p->addStrongRef();
+    else
+        p->addWeakRef();
+}
+
+template <class T>
+template <class TT>
+    requires std::convertible_to<TT*, T*>
+SharedWeakUnion<T>::SharedWeakUnion(SharedIntrusive<TT> const& rhs)
+{
+    auto p = rhs.unsafeGetRawPtr();
+    if (p)
+        p->addStrongRef();
+    unsafeSetRawPtr(p, RefStrength::strong);
+}
+
+template <class T>
+SharedWeakUnion<T>::SharedWeakUnion(SharedWeakUnion&& rhs) : tp_{rhs.tp_}
+{
+    rhs.unsafeSetRawPtr(nullptr);
+}
+
+template <class T>
+template <class TT>
+    requires std::convertible_to<TT*, T*>
+SharedWeakUnion<T>::SharedWeakUnion(SharedIntrusive<TT>&& rhs)
+{
+    auto p = rhs.unsafeGetRawPtr();
+    if (p)
+        unsafeSetRawPtr(p, RefStrength::strong);
+    rhs.unsafeSetRawPtr(nullptr);
+}
+
+template <class T>
+SharedWeakUnion<T>&
+SharedWeakUnion<T>::operator=(SharedWeakUnion const& rhs)
+{
+    if (this == &rhs)
+        return *this;
+    unsafeReleaseNoStore();
+
+    if (auto p = rhs.unsafeGetRawPtr())
+    {
+        if (rhs.isStrong())
+        {
+            p->addStrongRef();
+            unsafeSetRawPtr(p, RefStrength::strong);
+        }
+        else
+        {
+            p->addWeakRef();
+            unsafeSetRawPtr(p, RefStrength::weak);
+        }
+    }
+    else
+    {
+        unsafeSetRawPtr(nullptr);
+    }
+    return *this;
+}
+
+template <class T>
+template <class TT>
+// clang-format off
+requires std::convertible_to<TT*, T*>
+// clang-format on
+SharedWeakUnion<T>&
+SharedWeakUnion<T>::operator=(SharedIntrusive<TT> const& rhs)
+{
+    unsafeReleaseNoStore();
+    auto p = rhs.unsafeGetRawPtr();
+    if (p)
+        p->addStrongRef();
+    unsafeSetRawPtr(p, RefStrength::strong);
+    return *this;
+}
+
+template <class T>
+template <class TT>
+// clang-format off
+requires std::convertible_to<TT*, T*>
+// clang-format on
+SharedWeakUnion<T>&
+SharedWeakUnion<T>::operator=(SharedIntrusive<TT>&& rhs)
+{
+    unsafeReleaseNoStore();
+    unsafeSetRawPtr(rhs.unsafeGetRawPtr(), RefStrength::strong);
+    rhs.unsafeSetRawPtr(nullptr);
+    return *this;
+}
+
+template <class T>
+SharedWeakUnion<T>::~SharedWeakUnion()
+{
+    unsafeReleaseNoStore();
+};
+
+// Return a strong pointer if this is already a strong pointer (i.e. don't
+// lock the weak pointer. Use the `lock` method if that's what's needed)
+template <class T>
+SharedIntrusive<T>
+SharedWeakUnion<T>::getStrong() const
+{
+    SharedIntrusive<T> result;
+    auto p = unsafeGetRawPtr();
+    if (p && isStrong())
+    {
+        result.template adopt<SharedIntrusiveAdoptIncrementStrongTag>(p);
+    }
+    return result;
+}
+
+template <class T>
+SharedWeakUnion<T>::operator bool() const noexcept
+{
+    return bool(get());
+}
+
+template <class T>
+void
+SharedWeakUnion<T>::reset()
+{
+    unsafeReleaseNoStore();
+    unsafeSetRawPtr(nullptr);
+}
+
+template <class T>
+T*
+SharedWeakUnion<T>::get() const
+{
+    return isStrong() ? unsafeGetRawPtr() : nullptr;
+}
+
+template <class T>
+std::size_t
+SharedWeakUnion<T>::use_count() const
+{
+    if (auto p = get())
+        return p->use_count();
+    return 0;
+}
+
+template <class T>
+bool
+SharedWeakUnion<T>::expired() const
+{
+    auto p = unsafeGetRawPtr();
+    return (!p || p->expired());
+}
+
+template <class T>
+SharedIntrusive<T>
+SharedWeakUnion<T>::lock() const
+{
+    SharedIntrusive<T> result;
+    auto p = unsafeGetRawPtr();
+    if (!p)
+        return result;
+
+    if (isStrong())
+    {
+        result.template adopt<SharedIntrusiveAdoptIncrementStrongTag>(p);
+        return result;
+    }
+
+    if (p->checkoutStrongRefFromWeak())
+    {
+        result.template adopt<SharedIntrusiveAdoptNoIncrementTag>(p);
+        return result;
+    }
+    return result;
+}
+
+template <class T>
+bool
+SharedWeakUnion<T>::isStrong() const
+{
+    return !(tp_ & tagMask);
+}
+
+template <class T>
+bool
+SharedWeakUnion<T>::isWeak() const
+{
+    return tp_ & tagMask;
+}
+
+template <class T>
+bool
+SharedWeakUnion<T>::convertToStrong()
+{
+    if (isStrong())
+        return true;
+
+    auto p = unsafeGetRawPtr();
+    if (p && p->checkoutStrongRefFromWeak())
+    {
+        [[maybe_unused]] auto action = p->releaseWeakRef();
+        XRPL_ASSERT(
+            (action == ReleaseWeakRefAction::noop),
+            "ripple::SharedWeakUnion::convertToStrong : "
+            "action is noop");
+        unsafeSetRawPtr(p, RefStrength::strong);
+        return true;
+    }
+    return false;
+}
+
+template <class T>
+bool
+SharedWeakUnion<T>::convertToWeak()
+{
+    if (isWeak())
+        return true;
+
+    auto p = unsafeGetRawPtr();
+    if (!p)
+        return false;
+
+    using enum ReleaseStrongRefAction;
+    auto action = p->addWeakReleaseStrongRef();
+    switch (action)
+    {
+        case noop:
+            break;
+        case destroy:
+            // We just added a weak ref. How could we destroy?
+            UNREACHABLE(
+                "ripple::SharedWeakUnion::convertToWeak : destroying freshly "
+                "added ref");
+            delete p;
+            unsafeSetRawPtr(nullptr);
+            return true;  // Should never happen
+        case partialDestroy:
+            // This is a weird case. We just converted the last strong
+            // pointer to a weak pointer.
+            p->partialDestructor();
+            partialDestructorFinished(&p);
+            // p is null and may no longer be used
+            break;
+    }
+    unsafeSetRawPtr(p, RefStrength::weak);
+    return true;
+}
+
+template <class T>
+T*
+SharedWeakUnion<T>::unsafeGetRawPtr() const
+{
+    return reinterpret_cast<T*>(tp_ & ptrMask);
+}
+
+template <class T>
+void
+SharedWeakUnion<T>::unsafeSetRawPtr(T* p, RefStrength rs)
+{
+    tp_ = reinterpret_cast<std::uintptr_t>(p);
+    if (tp_ && rs == RefStrength::weak)
+        tp_ |= tagMask;
+}
+
+template <class T>
+void
+SharedWeakUnion<T>::unsafeSetRawPtr(std::nullptr_t)
+{
+    tp_ = 0;
+}
+
+template <class T>
+void
+SharedWeakUnion<T>::unsafeReleaseNoStore()
+{
+    auto p = unsafeGetRawPtr();
+    if (!p)
+        return;
+
+    if (isStrong())
+    {
+        using enum ReleaseStrongRefAction;
+        auto strongAction = p->releaseStrongRef();
+        switch (strongAction)
+        {
+            case noop:
+                break;
+            case destroy:
+                delete p;
+                break;
+            case partialDestroy:
+                p->partialDestructor();
+                partialDestructorFinished(&p);
+                // p is null and may no longer be used
+                break;
+        }
+    }
+    else
+    {
+        using enum ReleaseWeakRefAction;
+        auto weakAction = p->releaseWeakRef();
+        switch (weakAction)
+        {
+            case noop:
+                break;
+            case destroy:
+                delete p;
+                break;
+        }
+    }
+}
+
+}  // namespace ripple
+#endif

include/xrpl/basics/IntrusiveRefCounts.h

@@ -0,0 +1,502 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2023 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_BASICS_INTRUSIVEREFCOUNTS_H_INCLUDED
+#define RIPPLE_BASICS_INTRUSIVEREFCOUNTS_H_INCLUDED
+
+#include <xrpl/beast/utility/instrumentation.h>
+
+#include <atomic>
+#include <cstdint>
+
+namespace ripple {
+
+/** Action to perform when releasing a strong pointer.
+
+    noop: Do nothing. For example, a `noop` action will occur when a count is
+    decremented to a non-zero value.
+
+    partialDestroy: Run the `partialDestructor`. This action will happen when a
+    strong count is decremented to zero and the weak count is non-zero.
+
+    destroy: Run the destructor. This action will occur when either the strong
+    count or weak count is decremented and the other count is also zero.
+ */
+enum class ReleaseStrongRefAction { noop, partialDestroy, destroy };
+
+/** Action to perform when releasing a weak pointer.
+
+    noop: Do nothing. For example, a `noop` action will occur when a count is
+    decremented to a non-zero value.
+
+    destroy: Run the destructor. This action will occur when either the strong
+    count or weak count is decremented and the other count is also zero.
+ */
+enum class ReleaseWeakRefAction { noop, destroy };
+
+/** Implement the strong count, weak count, and bit flags for an intrusive
+    pointer.
+
+    A class can satisfy the requirements of a ripple::IntrusivePointer by
+    inheriting from this class.
+  */
+struct IntrusiveRefCounts
+{
+    virtual ~IntrusiveRefCounts() noexcept;
+
+    // This must be `noexcept` or the make_SharedIntrusive function could leak
+    // memory.
+    void
+    addStrongRef() const noexcept;
+
+    void
+    addWeakRef() const noexcept;
+
+    ReleaseStrongRefAction
+    releaseStrongRef() const;
+
+    // Same as:
+    // {
+    //   addWeakRef();
+    //   return releaseStrongRef;
+    // }
+    // done as one atomic operation
+    ReleaseStrongRefAction
+    addWeakReleaseStrongRef() const;
+
+    ReleaseWeakRefAction
+    releaseWeakRef() const;
+
+    // Returns true is able to checkout a strong ref. False otherwise
+    bool
+    checkoutStrongRefFromWeak() const noexcept;
+
+    bool
+    expired() const noexcept;
+
+    std::size_t
+    use_count() const noexcept;
+
+    // This function MUST be called after a partial destructor finishes running.
+    // Calling this function may cause other threads to delete the object
+    // pointed to by `o`, so `o` should never be used after calling this
+    // function. The parameter will be set to a `nullptr` after calling this
+    // function to emphasize that it should not be used.
+    // Note: This is intentionally NOT called at the end of `partialDestructor`.
+    // The reason for this is if new classes are written to support this smart
+    // pointer class, they need to write their own `partialDestructor` function
+    // and ensure `partialDestructorFinished` is called at the end. Putting this
+    // call inside the smart pointer class itself is expected to be less error
+    // prone.
+    // Note: The "two-star" programming is intentional. It emphasizes that `o`
+    // may be deleted and the unergonomic API is meant to signal the special
+    // nature of this function call to callers.
+    // Note: This is a template to support incompletely defined classes.
+    template <class T>
+    friend void
+    partialDestructorFinished(T** o);
+
+private:
+    // TODO: We may need to use a uint64_t for both counts. This will reduce the
+    // memory savings. We need to audit the code to make sure 16 bit counts are
+    // enough for strong pointers and 14 bit counts are enough for weak
+    // pointers. Use type aliases to make it easy to switch types.
+    using CountType = std::uint16_t;
+    static constexpr size_t StrongCountNumBits = sizeof(CountType) * 8;
+    static constexpr size_t WeakCountNumBits = StrongCountNumBits - 2;
+    using FieldType = std::uint32_t;
+    static constexpr size_t FieldTypeBits = sizeof(FieldType) * 8;
+    static constexpr FieldType one = 1;
+
+    /** `refCounts` consists of four fields that are treated atomically:
+
+         1. Strong count. This is a count of the number of shared pointers that
+         hold a reference to this object. When the strong counts goes to zero,
+         if the weak count is zero, the destructor is run. If the weak count is
+         non-zero when the strong count goes to zero then the partialDestructor
+         is run.
+
+         2. Weak count. This is a count of the number of weak pointer that hold
+         a reference to this object. When the weak count goes to zero and the
+         strong count is also zero, then the destructor is run.
+
+         3. Partial destroy started bit. This bit is set if the
+         `partialDestructor` function has been started (or is about to be
+         started). This is used to prevent the destructor from running
+         concurrently with the partial destructor. This can easily happen when
+         the last strong pointer release its reference in one thread and starts
+         the partialDestructor, while in another thread the last weak pointer
+         goes out of scope and starts the destructor while the partialDestructor
+         is still running. Both a start and finished bit is needed to handle a
+         corner-case where the last strong pointer goes out of scope, then then
+         last `weakPointer` goes out of scope, but this happens before the
+         `partialDestructor` bit is set. It would be possible to use a single
+         bit if it could also be set atomically when the strong count goes to
+         zero and the weak count is non-zero, but that would add complexity (and
+         likely slow down common cases as well).
+
+         4. Partial destroy finished bit. This bit is set when the
+         `partialDestructor` has finished running. See (3) above for more
+         information.
+
+         */
+
+    mutable std::atomic<FieldType> refCounts{strongDelta};
+
+    /**  Amount to change the strong count when adding or releasing a reference
+
+         Note: The strong count is stored in the low `StrongCountNumBits` bits
+       of refCounts
+      */
+    static constexpr FieldType strongDelta = 1;
+
+    /**  Amount to change the weak count when adding or releasing a reference
+
+         Note: The weak count is stored in the high `WeakCountNumBits` bits of
+         refCounts
+      */
+    static constexpr FieldType weakDelta = (one << StrongCountNumBits);
+
+    /**  Flag that is set when the partialDestroy function has started running
+         (or is about to start running).
+
+         See description of the `refCounts` field for a fuller description of
+         this field.
+      */
+    static constexpr FieldType partialDestroyStartedMask =
+        (one << (FieldTypeBits - 1));
+
+    /**  Flag that is set when the partialDestroy function has finished running
+
+         See description of the `refCounts` field for a fuller description of
+         this field.
+      */
+    static constexpr FieldType partialDestroyFinishedMask =
+        (one << (FieldTypeBits - 2));
+
+    /** Mask that will zero out all the `count` bits and leave the tag bits
+        unchanged.
+      */
+    static constexpr FieldType tagMask =
+        partialDestroyStartedMask | partialDestroyFinishedMask;
+
+    /** Mask that will zero out the `tag` bits and leave the count bits
+        unchanged.
+      */
+    static constexpr FieldType valueMask = ~tagMask;
+
+    /** Mask that will zero out everything except the strong count.
+     */
+    static constexpr FieldType strongMask =
+        ((one << StrongCountNumBits) - 1) & valueMask;
+
+    /** Mask that will zero out everything except the weak count.
+     */
+    static constexpr FieldType weakMask =
+        (((one << WeakCountNumBits) - 1) << StrongCountNumBits) & valueMask;
+
+    /** Unpack the count and tag fields from the packed atomic integer form. */
+    struct RefCountPair
+    {
+        CountType strong;
+        CountType weak;
+        /**  The `partialDestroyStartedBit` is set to on when the partial
+             destroy function is started. It is not a boolean; it is a uint32
+             with all bits zero with the possible exception of the
+             `partialDestroyStartedMask` bit. This is done so it can be directly
+             masked into the `combinedValue`.
+         */
+        FieldType partialDestroyStartedBit{0};
+        /**  The `partialDestroyFinishedBit` is set to on when the partial
+             destroy function has finished.
+         */
+        FieldType partialDestroyFinishedBit{0};
+        RefCountPair(FieldType v) noexcept;
+        RefCountPair(CountType s, CountType w) noexcept;
+
+        /** Convert back to the packed integer form. */
+        FieldType
+        combinedValue() const noexcept;
+
+        static constexpr CountType maxStrongValue =
+            static_cast<CountType>((one << StrongCountNumBits) - 1);
+        static constexpr CountType maxWeakValue =
+            static_cast<CountType>((one << WeakCountNumBits) - 1);
+        /**  Put an extra margin to detect when running up against limits.
+             This is only used in debug code, and is useful if we reduce the
+             number of bits in the strong and weak counts (to 16 and 14 bits).
+         */
+        static constexpr CountType checkStrongMaxValue = maxStrongValue - 32;
+        static constexpr CountType checkWeakMaxValue = maxWeakValue - 32;
+    };
+};
+
+inline void
+IntrusiveRefCounts::addStrongRef() const noexcept
+{
+    refCounts.fetch_add(strongDelta, std::memory_order_acq_rel);
+}
+
+inline void
+IntrusiveRefCounts::addWeakRef() const noexcept
+{
+    refCounts.fetch_add(weakDelta, std::memory_order_acq_rel);
+}
+
+inline ReleaseStrongRefAction
+IntrusiveRefCounts::releaseStrongRef() const
+{
+    // Subtract `strongDelta` from refCounts. If this releases the last strong
+    // ref, set the `partialDestroyStarted` bit. It is important that the ref
+    // count and the `partialDestroyStartedBit` are changed atomically (hence
+    // the loop and `compare_exchange` op). If this didn't need to be done
+    // atomically, the loop could be replaced with a `fetch_sub` and a
+    // conditional `fetch_or`. This loop will almost always run once.
+
+    using enum ReleaseStrongRefAction;
+    auto prevIntVal = refCounts.load(std::memory_order_acquire);
+    while (1)
+    {
+        RefCountPair const prevVal{prevIntVal};
+        XRPL_ASSERT(
+            (prevVal.strong >= strongDelta),
+            "ripple::IntrusiveRefCounts::releaseStrongRef : previous ref "
+            "higher than new");
+        auto nextIntVal = prevIntVal - strongDelta;
+        ReleaseStrongRefAction action = noop;
+        if (prevVal.strong == 1)
+        {
+            if (prevVal.weak == 0)
+            {
+                action = destroy;
+            }
+            else
+            {
+                nextIntVal |= partialDestroyStartedMask;
+                action = partialDestroy;
+            }
+        }
+
+        if (refCounts.compare_exchange_weak(
+                prevIntVal, nextIntVal, std::memory_order_acq_rel))
+        {
+            // Can't be in partial destroy because only decrementing the strong
+            // count to zero can start a partial destroy, and that can't happen
+            // twice.
+            XRPL_ASSERT(
+                (action == noop) || !(prevIntVal & partialDestroyStartedMask),
+                "ripple::IntrusiveRefCounts::releaseStrongRef : not in partial "
+                "destroy");
+            return action;
+        }
+    }
+}
+
+inline ReleaseStrongRefAction
+IntrusiveRefCounts::addWeakReleaseStrongRef() const
+{
+    using enum ReleaseStrongRefAction;
+
+    static_assert(weakDelta > strongDelta);
+    auto constexpr delta = weakDelta - strongDelta;
+    auto prevIntVal = refCounts.load(std::memory_order_acquire);
+    // This loop will almost always run once. The loop is needed to atomically
+    // change the counts and flags (the count could be atomically changed, but
+    // the flags depend on the current value of the counts).
+    //
+    // Note: If this becomes a perf bottleneck, the `partialDestoryStartedMask`
+    // may be able to be set non-atomically. But it is easier to reason about
+    // the code if the flag is set atomically.
+    while (1)
+    {
+        RefCountPair const prevVal{prevIntVal};
+        // Converted the last strong pointer to a weak pointer.
+        //
+        // Can't be in partial destroy because only decrementing the
+        // strong count to zero can start a partial destroy, and that
+        // can't happen twice.
+        XRPL_ASSERT(
+            (!prevVal.partialDestroyStartedBit),
+            "ripple::IntrusiveRefCounts::addWeakReleaseStrongRef : not in "
+            "partial destroy");
+
+        auto nextIntVal = prevIntVal + delta;
+        ReleaseStrongRefAction action = noop;
+        if (prevVal.strong == 1)
+        {
+            if (prevVal.weak == 0)
+            {
+                action = noop;
+            }
+            else
+            {
+                nextIntVal |= partialDestroyStartedMask;
+                action = partialDestroy;
+            }
+        }
+        if (refCounts.compare_exchange_weak(
+                prevIntVal, nextIntVal, std::memory_order_acq_rel))
+        {
+            XRPL_ASSERT(
+                (!(prevIntVal & partialDestroyStartedMask)),
+                "ripple::IntrusiveRefCounts::addWeakReleaseStrongRef : not "
+                "started partial destroy");
+            return action;
+        }
+    }
+}
+
+inline ReleaseWeakRefAction
+IntrusiveRefCounts::releaseWeakRef() const
+{
+    auto prevIntVal = refCounts.fetch_sub(weakDelta, std::memory_order_acq_rel);
+    RefCountPair prev = prevIntVal;
+    if (prev.weak == 1 && prev.strong == 0)
+    {
+        if (!prev.partialDestroyStartedBit)
+        {
+            // This case should only be hit if the partialDestroyStartedBit is
+            // set non-atomically (and even then very rarely). The code is kept
+            // in case we need to set the flag non-atomically for perf reasons.
+            refCounts.wait(prevIntVal, std::memory_order_acquire);
+            prevIntVal = refCounts.load(std::memory_order_acquire);
+            prev = RefCountPair{prevIntVal};
+        }
+        if (!prev.partialDestroyFinishedBit)
+        {
+            // partial destroy MUST finish before running a full destroy (when
+            // using weak pointers)
+            refCounts.wait(prevIntVal - weakDelta, std::memory_order_acquire);
+        }
+        return ReleaseWeakRefAction::destroy;
+    }
+    return ReleaseWeakRefAction::noop;
+}
+
+inline bool
+IntrusiveRefCounts::checkoutStrongRefFromWeak() const noexcept
+{
+    auto curValue = RefCountPair{1, 1}.combinedValue();
+    auto desiredValue = RefCountPair{2, 1}.combinedValue();
+
+    while (!refCounts.compare_exchange_weak(
+        curValue, desiredValue, std::memory_order_acq_rel))
+    {
+        RefCountPair const prev{curValue};
+        if (!prev.strong)
+            return false;
+
+        desiredValue = curValue + strongDelta;
+    }
+    return true;
+}
+
+inline bool
+IntrusiveRefCounts::expired() const noexcept
+{
+    RefCountPair const val = refCounts.load(std::memory_order_acquire);
+    return val.strong == 0;
+}
+
+inline std::size_t
+IntrusiveRefCounts::use_count() const noexcept
+{
+    RefCountPair const val = refCounts.load(std::memory_order_acquire);
+    return val.strong;
+}
+
+inline IntrusiveRefCounts::~IntrusiveRefCounts() noexcept
+{
+#ifndef NDEBUG
+    auto v = refCounts.load(std::memory_order_acquire);
+    XRPL_ASSERT(
+        (!(v & valueMask)),
+        "ripple::IntrusiveRefCounts::~IntrusiveRefCounts : count must be zero");
+    auto t = v & tagMask;
+    XRPL_ASSERT(
+        (!t || t == tagMask),
+        "ripple::IntrusiveRefCounts::~IntrusiveRefCounts : valid tag");
+#endif
+}
+
+//------------------------------------------------------------------------------
+
+inline IntrusiveRefCounts::RefCountPair::RefCountPair(
+    IntrusiveRefCounts::FieldType v) noexcept
+    : strong{static_cast<CountType>(v & strongMask)}
+    , weak{static_cast<CountType>((v & weakMask) >> StrongCountNumBits)}
+    , partialDestroyStartedBit{v & partialDestroyStartedMask}
+    , partialDestroyFinishedBit{v & partialDestroyFinishedMask}
+{
+    XRPL_ASSERT(
+        (strong < checkStrongMaxValue && weak < checkWeakMaxValue),
+        "ripple::IntrusiveRefCounts::RefCountPair(FieldType) : inputs inside "
+        "range");
+}
+
+inline IntrusiveRefCounts::RefCountPair::RefCountPair(
+    IntrusiveRefCounts::CountType s,
+    IntrusiveRefCounts::CountType w) noexcept
+    : strong{s}, weak{w}
+{
+    XRPL_ASSERT(
+        (strong < checkStrongMaxValue && weak < checkWeakMaxValue),
+        "ripple::IntrusiveRefCounts::RefCountPair(CountType, CountType) : "
+        "inputs inside range");
+}
+
+inline IntrusiveRefCounts::FieldType
+IntrusiveRefCounts::RefCountPair::combinedValue() const noexcept
+{
+    XRPL_ASSERT(
+        (strong < checkStrongMaxValue && weak < checkWeakMaxValue),
+        "ripple::IntrusiveRefCounts::RefCountPair::combinedValue : inputs "
+        "inside range");
+    return (static_cast<IntrusiveRefCounts::FieldType>(weak)
+            << IntrusiveRefCounts::StrongCountNumBits) |
+        static_cast<IntrusiveRefCounts::FieldType>(strong) |
+        partialDestroyStartedBit | partialDestroyFinishedBit;
+}
+
+template <class T>
+inline void
+partialDestructorFinished(T** o)
+{
+    T& self = **o;
+    IntrusiveRefCounts::RefCountPair p =
+        self.refCounts.fetch_or(IntrusiveRefCounts::partialDestroyFinishedMask);
+    XRPL_ASSERT(
+        (!p.partialDestroyFinishedBit && p.partialDestroyStartedBit &&
+         !p.strong),
+        "ripple::partialDestructorFinished : not a weak ref");
+    if (!p.weak)
+    {
+        // There was a weak count before the partial destructor ran (or we would
+        // have run the full destructor) and now there isn't a weak count. Some
+        // thread is waiting to run the destructor.
+        self.refCounts.notify_one();
+    }
+    // Set the pointer to null to emphasize that the object shouldn't be used
+    // after calling this function as it may be destroyed in another thread.
+    *o = nullptr;
+}
+//------------------------------------------------------------------------------
+
+}  // namespace ripple
+#endif

include/xrpl/basics/LocalValue.h

@@ -21,7 +21,7 @@
 #define RIPPLE_BASICS_LOCALVALUE_H_INCLUDED
 
 #include <boost/thread/tss.hpp>
-#include <chrono>
+
 #include <memory>
 #include <unordered_map>
 
@@ -34,16 +34,6 @@ struct LocalValues
     explicit LocalValues() = default;
 
     bool onCoro = true;
-    void* coroPtr = nullptr;  // Pointer to owning JobQueue::Coro (if any)
-
-    // When true, SHAMap::finishFetch() will poll-wait for missing nodes
-    // instead of returning empty. Only set by partial sync code paths.
-    bool partialSyncWait = false;
-
-    // Configurable timeout for SHAMap node fetching during partial sync.
-    // Zero means use the default (30s). RPC handlers can set this to
-    // customize poll-wait behavior.
-    std::chrono::milliseconds fetchTimeout{0};
 
     struct BasicValue
     {
@@ -138,57 +128,6 @@ LocalValue<T>::operator*()
             .emplace(this, std::make_unique<detail::LocalValues::Value<T>>(t_))
             .first->second->get());
 }
-
-// Returns pointer to current coroutine if running inside one, nullptr otherwise
-inline void*
-getCurrentCoroPtr()
-{
-    auto lvs = detail::getLocalValues().get();
-    if (lvs && lvs->onCoro)
-        return lvs->coroPtr;
-    return nullptr;
-}
-
-// Check if partial sync wait is enabled for the current coroutine context.
-inline bool
-isPartialSyncWaitEnabled()
-{
-    auto lvs = detail::getLocalValues().get();
-    if (lvs && lvs->onCoro)
-        return lvs->partialSyncWait;
-    return false;
-}
-
-// Enable/disable partial sync wait for the current coroutine context.
-inline void
-setPartialSyncWait(bool enabled)
-{
-    auto lvs = detail::getLocalValues().get();
-    if (lvs && lvs->onCoro)
-        lvs->partialSyncWait = enabled;
-}
-
-// Get the configured fetch timeout for current coroutine context.
-// Returns 0ms if not in a coroutine or no custom timeout set.
-inline std::chrono::milliseconds
-getCoroFetchTimeout()
-{
-    auto lvs = detail::getLocalValues().get();
-    if (lvs && lvs->onCoro)
-        return lvs->fetchTimeout;
-    return std::chrono::milliseconds{0};
-}
-
-// Set the fetch timeout for the current coroutine context.
-// Only works if called from within a coroutine.
-inline void
-setCoroFetchTimeout(std::chrono::milliseconds timeout)
-{
-    auto lvs = detail::getLocalValues().get();
-    if (lvs && lvs->onCoro)
-        lvs->fetchTimeout = timeout;
-}
-
 }  // namespace ripple
 
 #endif

include/xrpl/basics/Log.h

@@ -22,8 +22,10 @@
 
 #include <xrpl/basics/UnorderedContainers.h>
 #include <xrpl/beast/utility/Journal.h>
+
 #include <boost/beast/core/string.hpp>
 #include <boost/filesystem.hpp>
+
 #include <fstream>
 #include <map>
 #include <memory>

include/xrpl/basics/Resolver.h

@@ -20,11 +20,11 @@
 #ifndef RIPPLE_BASICS_RESOLVER_H_INCLUDED
 #define RIPPLE_BASICS_RESOLVER_H_INCLUDED
 
+#include <xrpl/beast/net/IPEndpoint.h>
+
 #include <functional>
 #include <vector>
 
-#include <xrpl/beast/net/IPEndpoint.h>
-
 namespace ripple {
 
 class Resolver

include/xrpl/basics/ResolverAsio.h

@@ -22,6 +22,7 @@
 
 #include <xrpl/basics/Resolver.h>
 #include <xrpl/beast/utility/Journal.h>
+
 #include <boost/asio/io_service.hpp>
 
 namespace ripple {

include/xrpl/basics/SharedWeakCachePointer.h

@@ -0,0 +1,135 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2023 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_BASICS_SHAREDWEAKCACHEPOINTER_H_INCLUDED
+#define RIPPLE_BASICS_SHAREDWEAKCACHEPOINTER_H_INCLUDED
+
+#include <memory>
+#include <variant>
+
+namespace ripple {
+
+/** A combination of a std::shared_ptr and a std::weak_pointer.
+
+
+This class is a wrapper to a `std::variant<std::shared_ptr,std::weak_ptr>`
+This class is useful for storing intrusive pointers in tagged caches using less
+memory than storing both pointers directly.
+*/
+
+template <class T>
+class SharedWeakCachePointer
+{
+public:
+    SharedWeakCachePointer() = default;
+
+    SharedWeakCachePointer(SharedWeakCachePointer const& rhs);
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedWeakCachePointer(std::shared_ptr<TT> const& rhs);
+
+    SharedWeakCachePointer(SharedWeakCachePointer&& rhs);
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedWeakCachePointer(std::shared_ptr<TT>&& rhs);
+
+    SharedWeakCachePointer&
+    operator=(SharedWeakCachePointer const& rhs);
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedWeakCachePointer&
+    operator=(std::shared_ptr<TT> const& rhs);
+
+    template <class TT>
+        requires std::convertible_to<TT*, T*>
+    SharedWeakCachePointer&
+    operator=(std::shared_ptr<TT>&& rhs);
+
+    ~SharedWeakCachePointer();
+
+    /** Return a strong pointer if this is already a strong pointer (i.e. don't
+        lock the weak pointer. Use the `lock` method if that's what's needed)
+     */
+    std::shared_ptr<T> const&
+    getStrong() const;
+
+    /** Return true if this is a strong pointer and the strong pointer is
+        seated.
+     */
+    explicit
+    operator bool() const noexcept;
+
+    /** Set the pointer to null, decrement the appropriate ref count, and run
+        the appropriate release action.
+     */
+    void
+    reset();
+
+    /** If this is a strong pointer, return the raw pointer. Otherwise return
+        null.
+     */
+    T*
+    get() const;
+
+    /** If this is a strong pointer, return the strong count. Otherwise return 0
+     */
+    std::size_t
+    use_count() const;
+
+    /** Return true if there is a non-zero strong count. */
+    bool
+    expired() const;
+
+    /** If this is a strong pointer, return the strong pointer. Otherwise
+        attempt to lock the weak pointer.
+     */
+    std::shared_ptr<T>
+    lock() const;
+
+    /** Return true is this represents a strong pointer. */
+    bool
+    isStrong() const;
+
+    /** Return true is this represents a weak pointer. */
+    bool
+    isWeak() const;
+
+    /** If this is a weak pointer, attempt to convert it to a strong pointer.
+
+        @return true if successfully converted to a strong pointer (or was
+                already a strong pointer). Otherwise false.
+      */
+    bool
+    convertToStrong();
+
+    /** If this is a strong pointer, attempt to convert it to a weak pointer.
+
+        @return false if the pointer is null. Otherwise return true.
+      */
+    bool
+    convertToWeak();
+
+private:
+    std::variant<std::shared_ptr<T>, std::weak_ptr<T>> combo_;
+};
+}  // namespace ripple
+#endif

include/xrpl/basics/SharedWeakCachePointer.ipp

@@ -0,0 +1,192 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of rippled: https://github.com/ripple/rippled
+    Copyright (c) 2023 Ripple Labs Inc.
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef RIPPLE_BASICS_SHAREDWEAKCACHEPOINTER_IPP_INCLUDED
+#define RIPPLE_BASICS_SHAREDWEAKCACHEPOINTER_IPP_INCLUDED
+
+#include <xrpl/basics/SharedWeakCachePointer.h>
+
+namespace ripple {
+template <class T>
+SharedWeakCachePointer<T>::SharedWeakCachePointer(
+    SharedWeakCachePointer const& rhs) = default;
+
+template <class T>
+template <class TT>
+    requires std::convertible_to<TT*, T*>
+SharedWeakCachePointer<T>::SharedWeakCachePointer(
+    std::shared_ptr<TT> const& rhs)
+    : combo_{rhs}
+{
+}
+
+template <class T>
+SharedWeakCachePointer<T>::SharedWeakCachePointer(
+    SharedWeakCachePointer&& rhs) = default;
+
+template <class T>
+template <class TT>
+    requires std::convertible_to<TT*, T*>
+SharedWeakCachePointer<T>::SharedWeakCachePointer(std::shared_ptr<TT>&& rhs)
+    : combo_{std::move(rhs)}
+{
+}
+
+template <class T>
+SharedWeakCachePointer<T>&
+SharedWeakCachePointer<T>::operator=(SharedWeakCachePointer const& rhs) =
+    default;
+
+template <class T>
+template <class TT>
+    requires std::convertible_to<TT*, T*>
+SharedWeakCachePointer<T>&
+SharedWeakCachePointer<T>::operator=(std::shared_ptr<TT> const& rhs)
+{
+    combo_ = rhs;
+    return *this;
+}
+
+template <class T>
+template <class TT>
+    requires std::convertible_to<TT*, T*>
+SharedWeakCachePointer<T>&
+SharedWeakCachePointer<T>::operator=(std::shared_ptr<TT>&& rhs)
+{
+    combo_ = std::move(rhs);
+    return *this;
+}
+
+template <class T>
+SharedWeakCachePointer<T>::~SharedWeakCachePointer() = default;
+
+// Return a strong pointer if this is already a strong pointer (i.e. don't
+// lock the weak pointer. Use the `lock` method if that's what's needed)
+template <class T>
+std::shared_ptr<T> const&
+SharedWeakCachePointer<T>::getStrong() const
+{
+    static std::shared_ptr<T> const empty;
+    if (auto p = std::get_if<std::shared_ptr<T>>(&combo_))
+        return *p;
+    return empty;
+}
+
+template <class T>
+SharedWeakCachePointer<T>::operator bool() const noexcept
+{
+    return !!std::get_if<std::shared_ptr<T>>(&combo_);
+}
+
+template <class T>
+void
+SharedWeakCachePointer<T>::reset()
+{
+    combo_ = std::shared_ptr<T>{};
+}
+
+template <class T>
+T*
+SharedWeakCachePointer<T>::get() const
+{
+    return std::get_if<std::shared_ptr<T>>(&combo_).get();
+}
+
+template <class T>
+std::size_t
+SharedWeakCachePointer<T>::use_count() const
+{
+    if (auto p = std::get_if<std::shared_ptr<T>>(&combo_))
+        return p->use_count();
+    return 0;
+}
+
+template <class T>
+bool
+SharedWeakCachePointer<T>::expired() const
+{
+    if (auto p = std::get_if<std::weak_ptr<T>>(&combo_))
+        return p->expired();
+    return !std::get_if<std::shared_ptr<T>>(&combo_);
+}
+
+template <class T>
+std::shared_ptr<T>
+SharedWeakCachePointer<T>::lock() const
+{
+    if (auto p = std::get_if<std::shared_ptr<T>>(&combo_))
+        return *p;
+
+    if (auto p = std::get_if<std::weak_ptr<T>>(&combo_))
+        return p->lock();
+
+    return {};
+}
+
+template <class T>
+bool
+SharedWeakCachePointer<T>::isStrong() const
+{
+    if (auto p = std::get_if<std::shared_ptr<T>>(&combo_))
+        return !!p->get();
+    return false;
+}
+
+template <class T>
+bool
+SharedWeakCachePointer<T>::isWeak() const
+{
+    return !isStrong();
+}
+
+template <class T>
+bool
+SharedWeakCachePointer<T>::convertToStrong()
+{
+    if (isStrong())
+        return true;
+
+    if (auto p = std::get_if<std::weak_ptr<T>>(&combo_))
+    {
+        if (auto s = p->lock())
+        {
+            combo_ = std::move(s);
+            return true;
+        }
+    }
+    return false;
+}
+
+template <class T>
+bool
+SharedWeakCachePointer<T>::convertToWeak()
+{
+    if (isWeak())
+        return true;
+
+    if (auto p = std::get_if<std::shared_ptr<T>>(&combo_))
+    {
+        combo_ = std::weak_ptr<T>(*p);
+        return true;
+    }
+
+    return false;
+}
+}  // namespace ripple
+#endif

include/xrpl/basics/Slice.h

@@ -23,6 +23,7 @@
 #include <xrpl/basics/contract.h>
 #include <xrpl/basics/strHex.h>
 #include <xrpl/beast/utility/instrumentation.h>
+
 #include <algorithm>
 #include <array>
 #include <cstdint>

include/xrpl/basics/TaggedCache.h

@@ -20,11 +20,14 @@
 #ifndef RIPPLE_BASICS_TAGGEDCACHE_H_INCLUDED
 #define RIPPLE_BASICS_TAGGEDCACHE_H_INCLUDED
 
+#include <xrpl/basics/IntrusivePointer.h>
 #include <xrpl/basics/Log.h>
+#include <xrpl/basics/SharedWeakCachePointer.ipp>
 #include <xrpl/basics/UnorderedContainers.h>
 #include <xrpl/basics/hardened_hash.h>
 #include <xrpl/beast/clock/abstract_clock.h>
 #include <xrpl/beast/insight/Insight.h>
+
 #include <atomic>
 #include <functional>
 #include <mutex>
@@ -50,6 +53,8 @@ template <
     class Key,
     class T,
     bool IsKeyCache = false,
+    class SharedWeakUnionPointerType = SharedWeakCachePointer<T>,
+    class SharedPointerType = std::shared_ptr<T>,
     class Hash = hardened_hash<>,
     class KeyEqual = std::equal_to<Key>,
     class Mutex = std::recursive_mutex>
@@ -60,6 +65,8 @@ public:
     using key_type = Key;
     using mapped_type = T;
     using clock_type = beast::abstract_clock<std::chrono::steady_clock>;
+    using shared_weak_combo_pointer_type = SharedWeakUnionPointerType;
+    using shared_pointer_type = SharedPointerType;
 
 public:
     TaggedCache(
@@ -69,231 +76,48 @@ public:
         clock_type& clock,
         beast::Journal journal,
         beast::insight::Collector::ptr const& collector =
-            beast::insight::NullCollector::New())
-        : m_journal(journal)
-        , m_clock(clock)
-        , m_stats(
-              name,
-              std::bind(&TaggedCache::collect_metrics, this),
-              collector)
-        , m_name(name)
-        , m_target_size(size)
-        , m_target_age(expiration)
-        , m_cache_count(0)
-        , m_hits(0)
-        , m_misses(0)
-    {
-    }
+            beast::insight::NullCollector::New());
 
 public:
     /** Return the clock associated with the cache. */
     clock_type&
-    clock()
-    {
-        return m_clock;
-    }
+    clock();
 
     /** Returns the number of items in the container. */
     std::size_t
-    size() const
-    {
-        std::lock_guard lock(m_mutex);
-        return m_cache.size();
-    }
-
-    void
-    setTargetSize(int s)
-    {
-        std::lock_guard lock(m_mutex);
-        m_target_size = s;
-
-        if (s > 0)
-        {
-            for (auto& partition : m_cache.map())
-            {
-                partition.rehash(static_cast<std::size_t>(
-                    (s + (s >> 2)) /
-                        (partition.max_load_factor() * m_cache.partitions()) +
-                    1));
-            }
-        }
-
-        JLOG(m_journal.debug()) << m_name << " target size set to " << s;
-    }
-
-    clock_type::duration
-    getTargetAge() const
-    {
-        std::lock_guard lock(m_mutex);
-        return m_target_age;
-    }
-
-    void
-    setTargetAge(clock_type::duration s)
-    {
-        std::lock_guard lock(m_mutex);
-        m_target_age = s;
-        JLOG(m_journal.debug())
-            << m_name << " target age set to " << m_target_age.count();
-    }
+    size() const;
 
     int
-    getCacheSize() const
-    {
-        std::lock_guard lock(m_mutex);
-        return m_cache_count;
-    }
+    getCacheSize() const;
 
     int
-    getTrackSize() const
-    {
-        std::lock_guard lock(m_mutex);
-        return m_cache.size();
-    }
+    getTrackSize() const;
 
     float
-    getHitRate()
-    {
-        std::lock_guard lock(m_mutex);
-        auto const total = static_cast<float>(m_hits + m_misses);
-        return m_hits * (100.0f / std::max(1.0f, total));
-    }
+    getHitRate();
 
     void
-    clear()
-    {
-        std::lock_guard lock(m_mutex);
-        m_cache.clear();
-        m_cache_count = 0;
-    }
+    clear();
 
     void
-    reset()
-    {
-        std::lock_guard lock(m_mutex);
-        m_cache.clear();
-        m_cache_count = 0;
-        m_hits = 0;
-        m_misses = 0;
-    }
+    reset();
 
     /** Refresh the last access time on a key if present.
         @return `true` If the key was found.
     */
     template <class KeyComparable>
     bool
-    touch_if_exists(KeyComparable const& key)
-    {
-        std::lock_guard lock(m_mutex);
-        auto const iter(m_cache.find(key));
-        if (iter == m_cache.end())
-        {
-            ++m_stats.misses;
-            return false;
-        }
-        iter->second.touch(m_clock.now());
-        ++m_stats.hits;
-        return true;
-    }
+    touch_if_exists(KeyComparable const& key);
 
-    using SweptPointersVector = std::pair<
-        std::vector<std::shared_ptr<mapped_type>>,
-        std::vector<std::weak_ptr<mapped_type>>>;
+    using SweptPointersVector = std::vector<SharedWeakUnionPointerType>;
 
     void
-    sweep()
-    {
-        // Keep references to all the stuff we sweep
-        // For performance, each worker thread should exit before the swept data
-        // is destroyed but still within the main cache lock.
-        std::vector<SweptPointersVector> allStuffToSweep(m_cache.partitions());
-
-        clock_type::time_point const now(m_clock.now());
-        clock_type::time_point when_expire;
-
-        auto const start = std::chrono::steady_clock::now();
-        {
-            std::lock_guard lock(m_mutex);
-
-            if (m_target_size == 0 ||
-                (static_cast<int>(m_cache.size()) <= m_target_size))
-            {
-                when_expire = now - m_target_age;
-            }
-            else
-            {
-                when_expire =
-                    now - m_target_age * m_target_size / m_cache.size();
-
-                clock_type::duration const minimumAge(std::chrono::seconds(1));
-                if (when_expire > (now - minimumAge))
-                    when_expire = now - minimumAge;
-
-                JLOG(m_journal.trace())
-                    << m_name << " is growing fast " << m_cache.size() << " of "
-                    << m_target_size << " aging at "
-                    << (now - when_expire).count() << " of "
-                    << m_target_age.count();
-            }
-
-            std::vector<std::thread> workers;
-            workers.reserve(m_cache.partitions());
-            std::atomic<int> allRemovals = 0;
-
-            for (std::size_t p = 0; p < m_cache.partitions(); ++p)
-            {
-                workers.push_back(sweepHelper(
-                    when_expire,
-                    now,
-                    m_cache.map()[p],
-                    allStuffToSweep[p],
-                    allRemovals,
-                    lock));
-            }
-            for (std::thread& worker : workers)
-                worker.join();
-
-            m_cache_count -= allRemovals;
-        }
-        // At this point allStuffToSweep will go out of scope outside the lock
-        // and decrement the reference count on each strong pointer.
-        JLOG(m_journal.debug())
-            << m_name << " TaggedCache sweep lock duration "
-            << std::chrono::duration_cast<std::chrono::milliseconds>(
-                   std::chrono::steady_clock::now() - start)
-                   .count()
-            << "ms";
-    }
+    sweep();
 
     bool
-    del(const key_type& key, bool valid)
-    {
-        // Remove from cache, if !valid, remove from map too. Returns true if
-        // removed from cache
-        std::lock_guard lock(m_mutex);
-
-        auto cit = m_cache.find(key);
-
-        if (cit == m_cache.end())
-            return false;
-
-        Entry& entry = cit->second;
-
-        bool ret = false;
-
-        if (entry.isCached())
-        {
-            --m_cache_count;
-            entry.ptr.reset();
-            ret = true;
-        }
-
-        if (!valid || entry.isExpired())
-            m_cache.erase(cit);
-
-        return ret;
-    }
+    del(key_type const& key, bool valid);
 
+public:
     /** Replace aliased objects with originals.
 
         Due to concurrency it is possible for two separate objects with
@@ -307,100 +131,23 @@ public:
 
         @return `true` If the key already existed.
     */
-public:
+    template <class R>
     bool
     canonicalize(
-        const key_type& key,
-        std::shared_ptr<T>& data,
-        std::function<bool(std::shared_ptr<T> const&)>&& replace)
-    {
-        // Return canonical value, store if needed, refresh in cache
-        // Return values: true=we had the data already
-        std::lock_guard lock(m_mutex);
-
-        auto cit = m_cache.find(key);
-
-        if (cit == m_cache.end())
-        {
-            m_cache.emplace(
-                std::piecewise_construct,
-                std::forward_as_tuple(key),
-                std::forward_as_tuple(m_clock.now(), data));
-            ++m_cache_count;
-            return false;
-        }
-
-        Entry& entry = cit->second;
-        entry.touch(m_clock.now());
-
-        if (entry.isCached())
-        {
-            if (replace(entry.ptr))
-            {
-                entry.ptr = data;
-                entry.weak_ptr = data;
-            }
-            else
-            {
-                data = entry.ptr;
-            }
-
-            return true;
-        }
-
-        auto cachedData = entry.lock();
-
-        if (cachedData)
-        {
-            if (replace(entry.ptr))
-            {
-                entry.ptr = data;
-                entry.weak_ptr = data;
-            }
-            else
-            {
-                entry.ptr = cachedData;
-                data = cachedData;
-            }
-
-            ++m_cache_count;
-            return true;
-        }
-
-        entry.ptr = data;
-        entry.weak_ptr = data;
-        ++m_cache_count;
-
-        return false;
-    }
+        key_type const& key,
+        SharedPointerType& data,
+        R&& replaceCallback);
 
     bool
     canonicalize_replace_cache(
-        const key_type& key,
-        std::shared_ptr<T> const& data)
-    {
-        return canonicalize(
-            key,
-            const_cast<std::shared_ptr<T>&>(data),
-            [](std::shared_ptr<T> const&) { return true; });
-    }
+        key_type const& key,
+        SharedPointerType const& data);
 
     bool
-    canonicalize_replace_client(const key_type& key, std::shared_ptr<T>& data)
-    {
-        return canonicalize(
-            key, data, [](std::shared_ptr<T> const&) { return false; });
-    }
+    canonicalize_replace_client(key_type const& key, SharedPointerType& data);
 
-    std::shared_ptr<T>
-    fetch(const key_type& key)
-    {
-        std::lock_guard<mutex_type> l(m_mutex);
-        auto ret = initialFetch(key, l);
-        if (!ret)
-            ++m_misses;
-        return ret;
-    }
+    SharedPointerType
+    fetch(key_type const& key);
 
     /** Insert the element into the container.
         If the key already exists, nothing happens.
@@ -409,26 +156,11 @@ public:
     template <class ReturnType = bool>
     auto
     insert(key_type const& key, T const& value)
-        -> std::enable_if_t<!IsKeyCache, ReturnType>
-    {
-        auto p = std::make_shared<T>(std::cref(value));
-        return canonicalize_replace_client(key, p);
-    }
+        -> std::enable_if_t<!IsKeyCache, ReturnType>;
 
     template <class ReturnType = bool>
     auto
-    insert(key_type const& key) -> std::enable_if_t<IsKeyCache, ReturnType>
-    {
-        std::lock_guard lock(m_mutex);
-        clock_type::time_point const now(m_clock.now());
-        auto [it, inserted] = m_cache.emplace(
-            std::piecewise_construct,
-            std::forward_as_tuple(key),
-            std::forward_as_tuple(now));
-        if (!inserted)
-            it->second.last_access = now;
-        return inserted;
-    }
+    insert(key_type const& key) -> std::enable_if_t<IsKeyCache, ReturnType>;
 
     // VFALCO NOTE It looks like this returns a copy of the data in
     //             the output parameter 'data'. This could be expensive.
@@ -436,50 +168,18 @@ public:
     //             simply return an iterator.
     //
     bool
-    retrieve(const key_type& key, T& data)
-    {
-        // retrieve the value of the stored data
-        auto entry = fetch(key);
-
-        if (!entry)
-            return false;
-
-        data = *entry;
-        return true;
-    }
+    retrieve(key_type const& key, T& data);
 
     mutex_type&
-    peekMutex()
-    {
-        return m_mutex;
-    }
+    peekMutex();
 
     std::vector<key_type>
-    getKeys() const
-    {
-        std::vector<key_type> v;
-
-        {
-            std::lock_guard lock(m_mutex);
-            v.reserve(m_cache.size());
-            for (auto const& _ : m_cache)
-                v.push_back(_.first);
-        }
-
-        return v;
-    }
+    getKeys() const;
 
     // CachedSLEs functions.
     /** Returns the fraction of cache hits. */
     double
-    rate() const
-    {
-        std::lock_guard lock(m_mutex);
-        auto const tot = m_hits + m_misses;
-        if (tot == 0)
-            return 0;
-        return double(m_hits) / tot;
-    }
+    rate() const;
 
     /** Fetch an item from the cache.
         If the digest was not found, Handler
@@ -487,73 +187,16 @@ public:
             std::shared_ptr<SLE const>(void)
     */
     template <class Handler>
-    std::shared_ptr<T>
-    fetch(key_type const& digest, Handler const& h)
-    {
-        {
-            std::lock_guard l(m_mutex);
-            if (auto ret = initialFetch(digest, l))
-                return ret;
-        }
-
-        auto sle = h();
-        if (!sle)
-            return {};
-
-        std::lock_guard l(m_mutex);
-        ++m_misses;
-        auto const [it, inserted] =
-            m_cache.emplace(digest, Entry(m_clock.now(), std::move(sle)));
-        if (!inserted)
-            it->second.touch(m_clock.now());
-        return it->second.ptr;
-    }
+    SharedPointerType
+    fetch(key_type const& digest, Handler const& h);
     // End CachedSLEs functions.
 
 private:
-    std::shared_ptr<T>
-    initialFetch(key_type const& key, std::lock_guard<mutex_type> const& l)
-    {
-        auto cit = m_cache.find(key);
-        if (cit == m_cache.end())
-            return {};
-
-        Entry& entry = cit->second;
-        if (entry.isCached())
-        {
-            ++m_hits;
-            entry.touch(m_clock.now());
-            return entry.ptr;
-        }
-        entry.ptr = entry.lock();
-        if (entry.isCached())
-        {
-            // independent of cache size, so not counted as a hit
-            ++m_cache_count;
-            entry.touch(m_clock.now());
-            return entry.ptr;
-        }
-
-        m_cache.erase(cit);
-        return {};
-    }
+    SharedPointerType
+    initialFetch(key_type const& key, std::lock_guard<mutex_type> const& l);
 
     void
-    collect_metrics()
-    {
-        m_stats.size.set(getCacheSize());
-
-        {
-            beast::insight::Gauge::value_type hit_rate(0);
-            {
-                std::lock_guard lock(m_mutex);
-                auto const total(m_hits + m_misses);
-                if (total != 0)
-                    hit_rate = (m_hits * 100) / total;
-            }
-            m_stats.hit_rate.set(hit_rate);
-        }
-    }
+    collect_metrics();
 
 private:
     struct Stats
@@ -599,36 +242,37 @@ private:
     class ValueEntry
     {
     public:
-        std::shared_ptr<mapped_type> ptr;
-        std::weak_ptr<mapped_type> weak_ptr;
+        shared_weak_combo_pointer_type ptr;
         clock_type::time_point last_access;
 
         ValueEntry(
             clock_type::time_point const& last_access_,
-            std::shared_ptr<mapped_type> const& ptr_)
-            : ptr(ptr_), weak_ptr(ptr_), last_access(last_access_)
+            shared_pointer_type const& ptr_)
+            : ptr(ptr_), last_access(last_access_)
         {
         }
 
         bool
         isWeak() const
         {
-            return ptr == nullptr;
+            if (!ptr)
+                return true;
+            return ptr.isWeak();
         }
         bool
         isCached() const
         {
-            return ptr != nullptr;
+            return ptr && ptr.isStrong();
         }
         bool
         isExpired() const
         {
-            return weak_ptr.expired();
+            return ptr.expired();
         }
-        std::shared_ptr<mapped_type>
+        SharedPointerType
         lock()
         {
-            return weak_ptr.lock();
+            return ptr.lock();
         }
         void
         touch(clock_type::time_point const& now)
@@ -657,72 +301,7 @@ private:
         typename KeyValueCacheType::map_type& partition,
         SweptPointersVector& stuffToSweep,
         std::atomic<int>& allRemovals,
-        std::lock_guard<std::recursive_mutex> const&)
-    {
-        return std::thread([&, this]() {
-            int cacheRemovals = 0;
-            int mapRemovals = 0;
-
-            // Keep references to all the stuff we sweep
-            // so that we can destroy them outside the lock.
-            stuffToSweep.first.reserve(partition.size());
-            stuffToSweep.second.reserve(partition.size());
-            {
-                auto cit = partition.begin();
-                while (cit != partition.end())
-                {
-                    if (cit->second.isWeak())
-                    {
-                        // weak
-                        if (cit->second.isExpired())
-                        {
-                            stuffToSweep.second.push_back(
-                                std::move(cit->second.weak_ptr));
-                            ++mapRemovals;
-                            cit = partition.erase(cit);
-                        }
-                        else
-                        {
-                            ++cit;
-                        }
-                    }
-                    else if (cit->second.last_access <= when_expire)
-                    {
-                        // strong, expired
-                        ++cacheRemovals;
-                        if (cit->second.ptr.use_count() == 1)
-                        {
-                            stuffToSweep.first.push_back(
-                                std::move(cit->second.ptr));
-                            ++mapRemovals;
-                            cit = partition.erase(cit);
-                        }
-                        else
-                        {
-                            // remains weakly cached
-                            cit->second.ptr.reset();
-                            ++cit;
-                        }
-                    }
-                    else
-                    {
-                        // strong, not expired
-                        ++cit;
-                    }
-                }
-            }
-
-            if (mapRemovals || cacheRemovals)
-            {
-                JLOG(m_journal.debug())
-                    << "TaggedCache partition sweep " << m_name
-                    << ": cache = " << partition.size() << "-" << cacheRemovals
-                    << ", map-=" << mapRemovals;
-            }
-
-            allRemovals += cacheRemovals;
-        });
-    }
+        std::lock_guard<std::recursive_mutex> const&);
 
     [[nodiscard]] std::thread
     sweepHelper(
@@ -731,45 +310,7 @@ private:
         typename KeyOnlyCacheType::map_type& partition,
         SweptPointersVector&,
         std::atomic<int>& allRemovals,
-        std::lock_guard<std::recursive_mutex> const&)
-    {
-        return std::thread([&, this]() {
-            int cacheRemovals = 0;
-            int mapRemovals = 0;
-
-            // Keep references to all the stuff we sweep
-            // so that we can destroy them outside the lock.
-            {
-                auto cit = partition.begin();
-                while (cit != partition.end())
-                {
-                    if (cit->second.last_access > now)
-                    {
-                        cit->second.last_access = now;
-                        ++cit;
-                    }
-                    else if (cit->second.last_access <= when_expire)
-                    {
-                        cit = partition.erase(cit);
-                    }
-                    else
-                    {
-                        ++cit;
-                    }
-                }
-            }
-
-            if (mapRemovals || cacheRemovals)
-            {
-                JLOG(m_journal.debug())
-                    << "TaggedCache partition sweep " << m_name
-                    << ": cache = " << partition.size() << "-" << cacheRemovals
-                    << ", map-=" << mapRemovals;
-            }
-
-            allRemovals += cacheRemovals;
-        });
-    };
+        std::lock_guard<std::recursive_mutex> const&);
 
     beast::Journal m_journal;
     clock_type& m_clock;
@@ -781,10 +322,10 @@ private:
     std::string m_name;
 
     // Desired number of cache entries (0 = ignore)
-    int m_target_size;
+    int const m_target_size;
 
     // Desired maximum cache age
-    clock_type::duration m_target_age;
+    clock_type::duration const m_target_age;
 
     // Number of items cached
     int m_cache_count;

include/xrpl/basics/UnorderedContainers.h

@@ -25,6 +25,7 @@
 #include <xrpl/beast/hash/hash_append.h>
 #include <xrpl/beast/hash/uhash.h>
 #include <xrpl/beast/hash/xxhasher.h>
+
 #include <unordered_map>
 #include <unordered_set>
 

include/xrpl/basics/base_uint.h

@@ -33,12 +33,13 @@
 #include <xrpl/basics/strHex.h>
 #include <xrpl/beast/utility/Zero.h>
 #include <xrpl/beast/utility/instrumentation.h>
+
 #include <boost/endian/conversion.hpp>
 #include <boost/functional/hash.hpp>
+
 #include <algorithm>
 #include <array>
 #include <cstring>
-#include <functional>
 #include <type_traits>
 
 namespace ripple {
@@ -385,7 +386,7 @@ public:
     }
 
     base_uint&
-    operator^=(const base_uint& b)
+    operator^=(base_uint const& b)
     {
         for (int i = 0; i < WIDTH; i++)
             data_[i] ^= b.data_[i];
@@ -394,7 +395,7 @@ public:
     }
 
     base_uint&
-    operator&=(const base_uint& b)
+    operator&=(base_uint const& b)
     {
         for (int i = 0; i < WIDTH; i++)
             data_[i] &= b.data_[i];
@@ -403,7 +404,7 @@ public:
     }
 
     base_uint&
-    operator|=(const base_uint& b)
+    operator|=(base_uint const& b)
     {
         for (int i = 0; i < WIDTH; i++)
             data_[i] |= b.data_[i];
@@ -426,11 +427,11 @@ public:
         return *this;
     }
 
-    const base_uint
+    base_uint const
     operator++(int)
     {
         // postfix operator
-        const base_uint ret = *this;
+        base_uint const ret = *this;
         ++(*this);
 
         return ret;
@@ -452,11 +453,11 @@ public:
         return *this;
     }
 
-    const base_uint
+    base_uint const
     operator--(int)
     {
         // postfix operator
-        const base_uint ret = *this;
+        base_uint const ret = *this;
         --(*this);
 
         return ret;
@@ -477,7 +478,7 @@ public:
     }
 
     base_uint&
-    operator+=(const base_uint& b)
+    operator+=(base_uint const& b)
     {
         std::uint64_t carry = 0;
 
@@ -522,7 +523,7 @@ public:
     }
 
     [[nodiscard]] constexpr bool
-    parseHex(const char* str)
+    parseHex(char const* str)
     {
         return parseHex(std::string_view{str});
     }

include/xrpl/basics/chrono.h

@@ -20,17 +20,16 @@
 #ifndef RIPPLE_BASICS_CHRONO_H_INCLUDED
 #define RIPPLE_BASICS_CHRONO_H_INCLUDED
 
-#include <date/date.h>
-
 #include <xrpl/beast/clock/abstract_clock.h>
 #include <xrpl/beast/clock/basic_seconds_clock.h>
 #include <xrpl/beast/clock/manual_clock.h>
 
+#include <date/date.h>
+
 #include <chrono>
 #include <cstdint>
 #include <ratio>
 #include <string>
-#include <type_traits>
 
 namespace ripple {
 

include/xrpl/basics/comparators.h

@@ -43,7 +43,7 @@ struct less
     using result_type = bool;
 
     constexpr bool
-    operator()(const T& left, const T& right) const
+    operator()(T const& left, T const& right) const
     {
         return std::less<T>()(left, right);
     }
@@ -55,7 +55,7 @@ struct equal_to
     using result_type = bool;
 
     constexpr bool
-    operator()(const T& left, const T& right) const
+    operator()(T const& left, T const& right) const
     {
         return std::equal_to<T>()(left, right);
     }

include/xrpl/basics/contract.h

@@ -21,9 +21,9 @@
 #define RIPPLE_BASICS_CONTRACT_H_INCLUDED
 
 #include <xrpl/beast/type_name.h>
+
 #include <exception>
 #include <string>
-#include <typeinfo>
 #include <utility>
 
 namespace ripple {

include/xrpl/basics/make_SSLContext.h

@@ -21,6 +21,7 @@
 #define RIPPLE_BASICS_MAKE_SSLCONTEXT_H_INCLUDED
 
 #include <boost/asio/ssl/context.hpp>
+
 #include <string>
 
 namespace ripple {

include/xrpl/basics/partitioned_unordered_map.h

@@ -22,6 +22,7 @@
 
 #include <xrpl/beast/hash/uhash.h>
 #include <xrpl/beast/utility/instrumentation.h>
+
 #include <functional>
 #include <optional>
 #include <string>
@@ -51,7 +52,7 @@ template <
     typename Value,
     typename Hash,
     typename Pred = std::equal_to<Key>,
-    typename Alloc = std::allocator<std::pair<const Key, Value>>>
+    typename Alloc = std::allocator<std::pair<Key const, Value>>>
 class partitioned_unordered_map
 {
     std::size_t partitions_;

include/xrpl/basics/random.h

@@ -22,9 +22,9 @@
 
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/beast/xor_shift_engine.h>
+
 #include <cstddef>
 #include <cstdint>
-#include <cstring>
 #include <limits>
 #include <mutex>
 #include <random>

include/xrpl/basics/spinlock.h

@@ -19,6 +19,7 @@
 #define RIPPLE_BASICS_SPINLOCK_H_INCLUDED
 
 #include <xrpl/beast/utility/instrumentation.h>
+
 #include <atomic>
 #include <limits>
 #include <type_traits>

include/xrpl/basics/tagged_integer.h

@@ -21,7 +21,9 @@
 #define BEAST_UTILITY_TAGGED_INTEGER_H_INCLUDED
 
 #include <xrpl/beast/hash/hash_append.h>
+
 #include <boost/operators.hpp>
+
 #include <functional>
 #include <iostream>
 #include <type_traits>
@@ -74,13 +76,13 @@ public:
     }
 
     bool
-    operator<(const tagged_integer& rhs) const noexcept
+    operator<(tagged_integer const& rhs) const noexcept
     {
         return m_value < rhs.m_value;
     }
 
     bool
-    operator==(const tagged_integer& rhs) const noexcept
+    operator==(tagged_integer const& rhs) const noexcept
     {
         return m_value == rhs.m_value;
     }
@@ -142,14 +144,14 @@ public:
     }
 
     tagged_integer&
-    operator<<=(const tagged_integer& rhs) noexcept
+    operator<<=(tagged_integer const& rhs) noexcept
     {
         m_value <<= rhs.m_value;
         return *this;
     }
 
     tagged_integer&
-    operator>>=(const tagged_integer& rhs) noexcept
+    operator>>=(tagged_integer const& rhs) noexcept
     {
         m_value >>= rhs.m_value;
         return *this;

include/xrpl/beast/asio/io_latency_probe.h

@@ -21,6 +21,7 @@
 #define BEAST_ASIO_IO_LATENCY_PROBE_H_INCLUDED
 
 #include <xrpl/beast/utility/instrumentation.h>
+
 #include <boost/asio/basic_waitable_timer.hpp>
 #include <boost/asio/io_service.hpp>
 

include/xrpl/beast/container/detail/aged_ordered_container.h

@@ -25,9 +25,11 @@
 #include <xrpl/beast/container/detail/aged_associative_container.h>
 #include <xrpl/beast/container/detail/aged_container_iterator.h>
 #include <xrpl/beast/container/detail/empty_base_optimization.h>
+
 #include <boost/intrusive/list.hpp>
 #include <boost/intrusive/set.hpp>
 #include <boost/version.hpp>
+
 #include <algorithm>
 #include <functional>
 #include <initializer_list>

include/xrpl/beast/container/detail/aged_unordered_container.h

@@ -25,8 +25,10 @@
 #include <xrpl/beast/container/detail/aged_associative_container.h>
 #include <xrpl/beast/container/detail/aged_container_iterator.h>
 #include <xrpl/beast/container/detail/empty_base_optimization.h>
+
 #include <boost/intrusive/list.hpp>
 #include <boost/intrusive/unordered_set.hpp>
+
 #include <algorithm>
 #include <cmath>
 #include <functional>

include/xrpl/beast/container/detail/empty_base_optimization.h

@@ -11,6 +11,7 @@
 #define BEAST_CONTAINER_DETAIL_EMPTY_BASE_OPTIMIZATION_H_INCLUDED
 
 #include <boost/type_traits/is_final.hpp>
+
 #include <type_traits>
 #include <utility>
 

include/xrpl/beast/core/LexicalCast.h

@@ -23,6 +23,7 @@
 #include <xrpl/beast/utility/instrumentation.h>
 
 #include <boost/core/detail/string_view.hpp>
+
 #include <algorithm>
 #include <cerrno>
 #include <charconv>

include/xrpl/beast/core/List.h

@@ -21,7 +21,6 @@
 #define BEAST_INTRUSIVE_LIST_H_INCLUDED
 
 #include <iterator>
-#include <type_traits>
 
 namespace beast {
 

include/xrpl/beast/hash/hash_append.h

@@ -23,6 +23,7 @@
 
 #include <boost/container/flat_set.hpp>
 #include <boost/endian/conversion.hpp>
+
 #include <array>
 #include <chrono>
 #include <cstdint>

include/xrpl/beast/hash/uhash.h

@@ -30,7 +30,7 @@ namespace beast {
 template <class Hasher = xxhasher>
 struct uhash
 {
-    explicit uhash() = default;
+    uhash() = default;
 
     using result_type = typename Hasher::result_type;
 

include/xrpl/beast/hash/xxhasher.h

@@ -21,6 +21,7 @@
 #define BEAST_HASH_XXHASHER_H_INCLUDED
 
 #include <boost/endian/conversion.hpp>
+
 #include <xxhash.h>
 
 #include <cstddef>

include/xrpl/beast/insight/Meter.h

@@ -20,10 +20,10 @@
 #ifndef BEAST_INSIGHT_METER_H_INCLUDED
 #define BEAST_INSIGHT_METER_H_INCLUDED
 
-#include <memory>
-
 #include <xrpl/beast/insight/MeterImpl.h>
 
+#include <memory>
+
 namespace beast {
 namespace insight {
 

include/xrpl/beast/insight/StatsDCollector.h

@@ -21,7 +21,6 @@
 #define BEAST_INSIGHT_STATSDCOLLECTOR_H_INCLUDED
 
 #include <xrpl/beast/insight/Collector.h>
-
 #include <xrpl/beast/net/IPEndpoint.h>
 #include <xrpl/beast/utility/Journal.h>
 

include/xrpl/beast/net/IPAddress.h

@@ -25,8 +25,10 @@
 #include <xrpl/beast/net/IPAddressV4.h>
 #include <xrpl/beast/net/IPAddressV6.h>
 #include <xrpl/beast/utility/instrumentation.h>
+
 #include <boost/asio/ip/address.hpp>
 #include <boost/functional/hash.hpp>
+
 #include <cstdint>
 #include <ios>
 #include <sstream>

include/xrpl/beast/net/IPAddressConversion.h

@@ -22,8 +22,6 @@
 
 #include <xrpl/beast/net/IPEndpoint.h>
 
-#include <sstream>
-
 #include <boost/asio.hpp>
 
 namespace beast {

include/xrpl/beast/net/IPAddressV4.h

@@ -21,7 +21,9 @@
 #define BEAST_NET_IPADDRESSV4_H_INCLUDED
 
 #include <xrpl/beast/hash/hash_append.h>
+
 #include <boost/asio/ip/address_v4.hpp>
+
 #include <cstdint>
 #include <functional>
 #include <ios>

include/xrpl/beast/net/IPAddressV6.h

@@ -21,7 +21,9 @@
 #define BEAST_NET_IPADDRESSV6_H_INCLUDED
 
 #include <xrpl/beast/utility/instrumentation.h>
+
 #include <boost/asio/ip/address_v6.hpp>
+
 #include <cstdint>
 #include <functional>
 #include <ios>

include/xrpl/beast/net/IPEndpoint.h

@@ -215,7 +215,7 @@ namespace std {
 template <>
 struct hash<::beast::IP::Endpoint>
 {
-    explicit hash() = default;
+    hash() = default;
 
     std::size_t
     operator()(::beast::IP::Endpoint const& endpoint) const
@@ -230,7 +230,7 @@ namespace boost {
 template <>
 struct hash<::beast::IP::Endpoint>
 {
-    explicit hash() = default;
+    hash() = default;
 
     std::size_t
     operator()(::beast::IP::Endpoint const& endpoint) const

include/xrpl/beast/rfc2616.h

@@ -20,10 +20,6 @@
 #ifndef BEAST_RFC2616_HPP
 #define BEAST_RFC2616_HPP
 
-// TODO: This include <cstdint> is a workaround for beast compilation bug.
-// Remove when fix https://github.com/boostorg/beast/pull/2682/ is available.
-#include <cstdint>
-
 #include <boost/beast/http/message.hpp>
 #include <boost/beast/http/rfc7230.hpp>
 #include <boost/range/algorithm/equal.hpp>
@@ -32,6 +28,7 @@
 
 #include <algorithm>
 #include <cctype>
+#include <cstdint>
 #include <iterator>
 #include <string>
 #include <utility>

include/xrpl/beast/test/yield_to.h

@@ -11,6 +11,7 @@
 #include <boost/asio/io_service.hpp>
 #include <boost/asio/spawn.hpp>
 #include <boost/optional.hpp>
+
 #include <condition_variable>
 #include <functional>
 #include <mutex>

include/xrpl/beast/unit_test/match.h

@@ -9,6 +9,7 @@
 #define BEAST_UNIT_TEST_MATCH_HPP
 
 #include <xrpl/beast/unit_test/suite_info.h>
+
 #include <string>
 
 namespace beast {

include/xrpl/beast/unit_test/reporter.h

@@ -10,8 +10,10 @@
 
 #include <xrpl/beast/unit_test/amount.h>
 #include <xrpl/beast/unit_test/recorder.h>
+
 #include <boost/lexical_cast.hpp>
 #include <boost/optional.hpp>
+
 #include <algorithm>
 #include <chrono>
 #include <functional>

include/xrpl/beast/unit_test/runner.h

@@ -9,7 +9,9 @@
 #define BEAST_UNIT_TEST_RUNNER_H_INCLUDED
 
 #include <xrpl/beast/unit_test/suite_info.h>
+
 #include <boost/assert.hpp>
+
 #include <mutex>
 #include <ostream>
 #include <string>

include/xrpl/beast/unit_test/suite.h

@@ -9,9 +9,11 @@
 #define BEAST_UNIT_TEST_SUITE_HPP
 
 #include <xrpl/beast/unit_test/runner.h>
+
 #include <boost/filesystem.hpp>
 #include <boost/lexical_cast.hpp>
 #include <boost/throw_exception.hpp>
+
 #include <ostream>
 #include <sstream>
 #include <string>

include/xrpl/beast/unit_test/suite_list.h

@@ -10,7 +10,9 @@
 
 #include <xrpl/beast/unit_test/detail/const_container.h>
 #include <xrpl/beast/unit_test/suite_info.h>
+
 #include <boost/assert.hpp>
+
 #include <set>
 #include <typeindex>
 #include <unordered_set>

include/xrpl/beast/unit_test/thread.h

@@ -9,6 +9,7 @@
 #define BEAST_UNIT_TEST_THREAD_HPP
 
 #include <xrpl/beast/unit_test/suite.h>
+
 #include <functional>
 #include <thread>
 #include <utility>

include/xrpl/beast/utility/EnhancedLogging.h

@@ -32,14 +32,14 @@ should_log_use_colors();
 
 // Get the log highlight color - can be overridden via
 // LOG_HIGHLIGHT_COLOR
-const char*
+char const*
 get_log_highlight_color();
 
 // Strip source root path from __FILE__ at compile time
 // IMPORTANT: This MUST stay in the header as constexpr for compile-time
 // evaluation!
-constexpr const char*
-strip_source_root(const char* file)
+constexpr char const*
+strip_source_root(char const* file)
 {
     // Handle relative paths from build/ directory (common with ccache)
     // e.g., "../src/ripple/..." -> "ripple/..."
@@ -50,15 +50,15 @@ strip_source_root(const char* file)
     }
 
 #ifdef SOURCE_ROOT_PATH
-    constexpr const char* sourceRoot = SOURCE_ROOT_PATH;
-    constexpr auto strlen_constexpr = [](const char* s) constexpr {
-        const char* p = s;
+    constexpr char const* sourceRoot = SOURCE_ROOT_PATH;
+    constexpr auto strlen_constexpr = [](char const* s) constexpr {
+        char const* p = s;
         while (*p)
             ++p;
         return p - s;
     };
     constexpr auto strncmp_constexpr =
-        [](const char* a, const char* b, size_t n) constexpr {
+        [](char const* a, char const* b, size_t n) constexpr {
             for (size_t i = 0; i < n; ++i)
             {
                 if (a[i] != b[i])
@@ -83,7 +83,7 @@ should_show_location();
 
 // Helper to write location string (no leading/trailing space)
 void
-log_write_location_string(std::ostream& os, const char* file, int line);
+log_write_location_string(std::ostream& os, char const* file, int line);
 
 }  // namespace detail
 }  // namespace beast

include/xrpl/beast/utility/Journal.h

@@ -21,6 +21,7 @@
 #define BEAST_UTILITY_JOURNAL_H_INCLUDED
 
 #include <xrpl/beast/utility/instrumentation.h>
+
 #include <sstream>
 
 namespace beast {
@@ -156,7 +157,7 @@ public:
         ScopedStream(Sink& sink, Severity level);
 
 #ifdef BEAST_ENHANCED_LOGGING
-        ScopedStream(Sink& sink, Severity level, const char* file, int line);
+        ScopedStream(Sink& sink, Severity level, char const* file, int line);
 #endif
 
         template <typename T>
@@ -187,7 +188,7 @@ public:
         Severity const m_level;
         std::ostringstream mutable m_ostream;
 #ifdef BEAST_ENHANCED_LOGGING
-        const char* file_ = nullptr;
+        char const* file_ = nullptr;
         int line_ = 0;
 #endif
     };
@@ -215,7 +216,7 @@ public:
     class StreamWithLocation
     {
     public:
-        StreamWithLocation(Stream const& stream, const char* file, int line)
+        StreamWithLocation(Stream const& stream, char const* file, int line)
             : file_(file), line_(line), stream_(stream)
         {
         }
@@ -229,9 +230,9 @@ public:
         operator<<(std::ostream& manip(std::ostream&)) const;
 
     private:
-        const char* file_;
+        char const* file_;
         int line_;
-        const Stream& stream_;
+        Stream const& stream_;
     };
 #endif
 
@@ -305,7 +306,7 @@ public:
 #ifdef BEAST_ENHANCED_LOGGING
         /** Create a StreamWithLocation that prepends file:line info */
         StreamWithLocation
-        withLocation(const char* file, int line) const
+        withLocation(char const* file, int line) const
         {
             return StreamWithLocation(*this, file, line);
         }

include/xrpl/beast/utility/PropertyStream.h

@@ -22,11 +22,9 @@
 
 #include <xrpl/beast/core/List.h>
 
-#include <cstdint>
 #include <mutex>
 #include <sstream>
 #include <string>
-#include <utility>
 
 namespace beast {
 

include/xrpl/beast/utility/rngfill.h

@@ -21,6 +21,7 @@
 #define BEAST_RANDOM_RNGFILL_H_INCLUDED
 
 #include <xrpl/beast/utility/instrumentation.h>
+
 #include <array>
 #include <cstdint>
 #include <cstring>

include/xrpl/beast/utility/temp_dir.h

@@ -21,6 +21,7 @@
 #define BEAST_UTILITY_TEMP_DIR_H_INCLUDED
 
 #include <boost/filesystem.hpp>
+
 #include <string>
 
 namespace beast {
@@ -36,9 +37,9 @@ class temp_dir
 
 public:
 #if !GENERATING_DOCS
-    temp_dir(const temp_dir&) = delete;
+    temp_dir(temp_dir const&) = delete;
     temp_dir&
-    operator=(const temp_dir&) = delete;
+    operator=(temp_dir const&) = delete;
 #endif
 
     /// Construct a temporary directory.

include/xrpl/crypto/csprng.h

@@ -21,8 +21,6 @@
 #define RIPPLE_CRYPTO_RANDOM_H_INCLUDED
 
 #include <mutex>
-#include <string>
-#include <type_traits>
 
 namespace ripple {
 

include/xrpl/hook/Enum.h

@@ -20,7 +20,7 @@ namespace hook_api {
 struct Rules
 {
     constexpr bool
-    enabled(const uint256& feature) const
+    enabled(uint256 const& feature) const
     {
         return true;
     }
@@ -393,12 +393,12 @@ enum ExitType : uint8_t {
     ACCEPT = 3,
 };
 
-const uint16_t max_state_modifications = 256;
-const uint8_t max_slots = 255;
-const uint8_t max_nonce = 255;
-const uint8_t max_emit = 255;
-const uint8_t max_params = 16;
-const double fee_base_multiplier = 1.1f;
+uint16_t const max_state_modifications = 256;
+uint8_t const max_slots = 255;
+uint8_t const max_nonce = 255;
+uint8_t const max_emit = 255;
+uint8_t const max_params = 16;
+double const fee_base_multiplier = 1.1f;
 
 using APIWhitelist = std::map<std::string, std::vector<uint8_t>>;
 

include/xrpl/hook/Guard.h

@@ -1,4 +1,5 @@
 #include "Enum.h"
+
 #include <functional>
 #include <iostream>
 #include <map>
@@ -204,7 +205,7 @@ struct WasmBlkInf
     }
 // compute worst case execution time
 inline uint64_t
-compute_wce(const WasmBlkInf* blk, int level, bool* recursion_limit_reached)
+compute_wce(WasmBlkInf const* blk, int level, bool* recursion_limit_reached)
 {
     if (level > 16)
     {
@@ -971,7 +972,7 @@ validateGuards(
                 }
 
                 if (std::string_view(
-                        (const char*)(wasm.data() + i), (size_t)mod_length) !=
+                        (char const*)(wasm.data() + i), (size_t)mod_length) !=
                     "env")
                 {
                     GUARDLOG(hook::log::IMPORT_MODULE_ENV)
@@ -999,7 +1000,7 @@ validateGuards(
                 }
 
                 std::string import_name{
-                    (const char*)(wasm.data() + i), (size_t)name_length};
+                    (char const*)(wasm.data() + i), (size_t)name_length};
 
                 i += name_length;
                 CHECK_SHORT_HOOK();

include/xrpl/hook/Misc.h

@@ -6,7 +6,7 @@ namespace ripple {
 // RH TODO: there's definitely a mucher nicer way to do this, but it involves
 // modifying the base_uint class and we don't want to do that yet.
 
-static const std::array<ripple::uint256, 256> UINT256_BIT = {
+static std::array<ripple::uint256, 256> const UINT256_BIT = {
     ripple::uint256(
         "0000000000000000000000000000000000000000000000000000000000000001"),
     ripple::uint256(

include/xrpl/hook/guard_checker.cpp

@@ -2,22 +2,21 @@
 #include "Enum.h"
 #include "Guard.h"
 #include <fcntl.h>
-#include <iostream>
-#include <optional>
-#include <ostream>
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>
-#include <string_view>
-#include <sys/ioctl.h>
-#include <sys/stat.h>
 #include <unistd.h>
+
+#include <iostream>
+#include <optional>
+#include <ostream>
+#include <string_view>
 #include <vector>
 
 int
 main(int argc, char** argv)
 {
-    const char* fin = 0;
+    char const* fin = 0;
 
     if (argc > 2)
         return fprintf(

include/xrpl/hook/xahau.h

@@ -2,7 +2,7 @@
 #define XAHAU_GENESIS_HOOKS
 #include <vector>
 
-static const std::vector<uint8_t> GovernanceHook = {
+static std::vector<uint8_t> const GovernanceHook = {
     0x00U, 0x61U, 0x73U, 0x6DU, 0x01U, 0x00U, 0x00U, 0x00U, 0x01U, 0x42U, 0x09U,
     0x60U, 0x02U, 0x7FU, 0x7FU, 0x01U, 0x7FU, 0x60U, 0x01U, 0x7FU, 0x01U, 0x7EU,
     0x60U, 0x04U, 0x7FU, 0x7FU, 0x7FU, 0x7FU, 0x01U, 0x7EU, 0x60U, 0x03U, 0x7FU,
@@ -813,7 +813,7 @@ static const std::vector<uint8_t> GovernanceHook = {
     0xB5U, 0xF7U, 0x62U, 0x79U, 0x8AU, 0x53U, 0xD5U, 0x43U, 0xA0U, 0x14U, 0xCAU,
     0xF8U, 0xB2U, 0x97U, 0xCFU, 0xF8U, 0xF2U, 0xF9U, 0x37U, 0xE8U};
 
-static const std::vector<uint8_t> RewardHook = {
+static std::vector<uint8_t> const RewardHook = {
     0x00U, 0x61U, 0x73U, 0x6DU, 0x01U, 0x00U, 0x00U, 0x00U, 0x01U, 0x61U, 0x0EU,
     0x60U, 0x01U, 0x7FU, 0x01U, 0x7EU, 0x60U, 0x02U, 0x7FU, 0x7FU, 0x01U, 0x7FU,
     0x60U, 0x00U, 0x01U, 0x7EU, 0x60U, 0x03U, 0x7FU, 0x7FU, 0x7EU, 0x01U, 0x7EU,

include/xrpl/json/Object.h

@@ -21,6 +21,7 @@
 #define RIPPLE_JSON_OBJECT_H_INCLUDED
 
 #include <xrpl/json/Writer.h>
+
 #include <memory>
 
 namespace Json {

include/xrpl/json/Output.h

@@ -21,6 +21,7 @@
 #define RIPPLE_JSON_OUTPUT_H_INCLUDED
 
 #include <boost/beast/core/string.hpp>
+
 #include <functional>
 #include <string>
 

include/xrpl/json/Writer.h

@@ -24,6 +24,7 @@
 #include <xrpl/basics/contract.h>
 #include <xrpl/json/Output.h>
 #include <xrpl/json/json_value.h>
+
 #include <memory>
 
 namespace Json {

include/xrpl/json/detail/json_assert.h

@@ -20,6 +20,7 @@
 #ifndef RIPPLE_JSON_JSON_ASSERT_H_INCLUDED
 #define RIPPLE_JSON_JSON_ASSERT_H_INCLUDED
 
+#include <xrpl/basics/contract.h>
 #include <xrpl/json/json_errors.h>
 
 #define JSON_ASSERT_MESSAGE(condition, message) \

include/xrpl/json/json_reader.h

@@ -24,7 +24,9 @@
 
 #include <xrpl/json/json_forwards.h>
 #include <xrpl/json/json_value.h>
+
 #include <boost/asio/buffer.hpp>
+
 #include <stack>
 
 namespace Json {
@@ -37,7 +39,7 @@ class Reader
 {
 public:
     using Char = char;
-    using Location = const Char*;
+    using Location = Char const*;
 
     /** \brief Constructs a Reader allowing all features
      * for parsing.
@@ -62,7 +64,7 @@ public:
      * error occurred.
      */
     bool
-    parse(const char* beginDoc, const char* endDoc, Value& root);
+    parse(char const* beginDoc, char const* endDoc, Value& root);
 
     /// \brief Parse from input stream.
     /// \see Json::operator>>(std::istream&, Json::Value&).
@@ -131,7 +133,7 @@ private:
     using Errors = std::deque<ErrorInfo>;
 
     bool
-    expectToken(TokenType type, Token& token, const char* message);
+    expectToken(TokenType type, Token& token, char const* message);
     bool
     readToken(Token& token);
     void

include/xrpl/json/json_value.h

@@ -20,10 +20,13 @@
 #ifndef RIPPLE_JSON_JSON_VALUE_H_INCLUDED
 #define RIPPLE_JSON_JSON_VALUE_H_INCLUDED
 
+#include <xrpl/basics/Number.h>
 #include <xrpl/json/json_forwards.h>
+
 #include <cstring>
 #include <map>
 #include <string>
+#include <utility>
 #include <vector>
 
 /** \brief JSON (JavaScript Object Notation).
@@ -60,24 +63,24 @@ enum ValueType {
 class StaticString
 {
 public:
-    constexpr explicit StaticString(const char* czstring) : str_(czstring)
+    constexpr explicit StaticString(char const* czstring) : str_(czstring)
     {
     }
 
     constexpr
-    operator const char*() const
+    operator char const*() const
     {
         return str_;
     }
 
-    constexpr const char*
+    constexpr char const*
     c_str() const
     {
         return str_;
     }
 
 private:
-    const char* str_;
+    char const* str_;
 };
 
 inline bool
@@ -155,10 +158,10 @@ public:
     using Int = Json::Int;
     using ArrayIndex = UInt;
 
-    static const Value null;
-    static const Int minInt;
-    static const Int maxInt;
-    static const UInt maxUInt;
+    static Value const null;
+    static Int const minInt;
+    static Int const maxInt;
+    static UInt const maxUInt;
 
 private:
     class CZString
@@ -170,24 +173,24 @@ private:
             duplicateOnCopy
         };
         CZString(int index);
-        CZString(const char* cstr, DuplicationPolicy allocate);
-        CZString(const CZString& other);
+        CZString(char const* cstr, DuplicationPolicy allocate);
+        CZString(CZString const& other);
         ~CZString();
         CZString&
-        operator=(const CZString& other) = delete;
+        operator=(CZString const& other) = delete;
         bool
-        operator<(const CZString& other) const;
+        operator<(CZString const& other) const;
         bool
-        operator==(const CZString& other) const;
+        operator==(CZString const& other) const;
         int
         index() const;
-        const char*
+        char const*
         c_str() const;
         bool
         isStaticString() const;
 
     private:
-        const char* cstr_;
+        char const* cstr_;
         int index_;
     };
 
@@ -214,7 +217,8 @@ public:
     Value(Int value);
     Value(UInt value);
     Value(double value);
-    Value(const char* value);
+    Value(char const* value);
+    Value(ripple::Number const& value);
     /** \brief Constructs a value from a static string.
 
      * Like other value string constructor but do not duplicate the string for
@@ -226,10 +230,10 @@ public:
      * Json::Value aValue( StaticString("some text") );
      * \endcode
      */
-    Value(const StaticString& value);
+    Value(StaticString const& value);
     Value(std::string const& value);
     Value(bool value);
-    Value(const Value& other);
+    Value(Value const& other);
     ~Value();
 
     Value&
@@ -246,7 +250,7 @@ public:
     ValueType
     type() const;
 
-    const char*
+    char const*
     asCString() const;
     /** Returns the unquoted string value. */
     std::string
@@ -316,12 +320,12 @@ public:
     /// Access an array element (zero based index )
     /// (You may need to say 'value[0u]' to get your compiler to distinguish
     ///  this from the operator[] which takes a string.)
-    const Value&
+    Value const&
     operator[](UInt index) const;
     /// If the array contains at least index+1 elements, returns the element
     /// value, otherwise returns defaultValue.
     Value
-    get(UInt index, const Value& defaultValue) const;
+    get(UInt index, Value const& defaultValue) const;
     /// Return true if index < size().
     bool
     isValidIndex(UInt index) const;
@@ -329,25 +333,25 @@ public:
     ///
     /// Equivalent to jsonvalue[jsonvalue.size()] = value;
     Value&
-    append(const Value& value);
+    append(Value const& value);
     Value&
     append(Value&& value);
 
     /// Access an object value by name, create a null member if it does not
     /// exist.
     Value&
-    operator[](const char* key);
+    operator[](char const* key);
     /// Access an object value by name, returns null if there is no member with
     /// that name.
-    const Value&
-    operator[](const char* key) const;
+    Value const&
+    operator[](char const* key) const;
     /// Access an object value by name, create a null member if it does not
     /// exist.
     Value&
     operator[](std::string const& key);
     /// Access an object value by name, returns null if there is no member with
     /// that name.
-    const Value&
+    Value const&
     operator[](std::string const& key) const;
     /** \brief Access an object value by name, create a null member if it does
      not exist.
@@ -363,14 +367,16 @@ public:
      * \endcode
      */
     Value&
-    operator[](const StaticString& key);
+    operator[](StaticString const& key);
+    Value const&
+    operator[](StaticString const& key) const;
 
     /// Return the member named key if it exist, defaultValue otherwise.
     Value
-    get(const char* key, const Value& defaultValue) const;
+    get(char const* key, Value const& defaultValue) const;
     /// Return the member named key if it exist, defaultValue otherwise.
     Value
-    get(std::string const& key, const Value& defaultValue) const;
+    get(std::string const& key, Value const& defaultValue) const;
 
     /// \brief Remove and return the named member.
     ///
@@ -379,14 +385,14 @@ public:
     /// \pre type() is objectValue or nullValue
     /// \post type() is unchanged
     Value
-    removeMember(const char* key);
+    removeMember(char const* key);
     /// Same as removeMember(const char*)
     Value
     removeMember(std::string const& key);
 
     /// Return true if the object has a member named key.
     bool
-    isMember(const char* key) const;
+    isMember(char const* key) const;
     /// Return true if the object has a member named key.
     bool
     isMember(std::string const& key) const;
@@ -413,13 +419,13 @@ public:
     end();
 
     friend bool
-    operator==(const Value&, const Value&);
+    operator==(Value const&, Value const&);
     friend bool
-    operator<(const Value&, const Value&);
+    operator<(Value const&, Value const&);
 
 private:
     Value&
-    resolveReference(const char* key, bool isStatic);
+    resolveReference(char const* key, bool isStatic);
 
 private:
     union ValueHolder
@@ -435,32 +441,38 @@ private:
     int allocated_ : 1;  // Notes: if declared as bool, bitfield is useless.
 };
 
+inline Value
+to_json(ripple::Number const& number)
+{
+    return to_string(number);
+}
+
 bool
-operator==(const Value&, const Value&);
+operator==(Value const&, Value const&);
 
 inline bool
-operator!=(const Value& x, const Value& y)
+operator!=(Value const& x, Value const& y)
 {
     return !(x == y);
 }
 
 bool
-operator<(const Value&, const Value&);
+operator<(Value const&, Value const&);
 
 inline bool
-operator<=(const Value& x, const Value& y)
+operator<=(Value const& x, Value const& y)
 {
     return !(y < x);
 }
 
 inline bool
-operator>(const Value& x, const Value& y)
+operator>(Value const& x, Value const& y)
 {
     return y < x;
 }
 
 inline bool
-operator>=(const Value& x, const Value& y)
+operator>=(Value const& x, Value const& y)
 {
     return !(x < y);
 }
@@ -481,11 +493,11 @@ public:
     virtual ~ValueAllocator() = default;
 
     virtual char*
-    makeMemberName(const char* memberName) = 0;
+    makeMemberName(char const* memberName) = 0;
     virtual void
     releaseMemberName(char* memberName) = 0;
     virtual char*
-    duplicateStringValue(const char* value, unsigned int length = unknown) = 0;
+    duplicateStringValue(char const* value, unsigned int length = unknown) = 0;
     virtual void
     releaseStringValue(char* value) = 0;
 };
@@ -502,16 +514,16 @@ public:
 
     ValueIteratorBase();
 
-    explicit ValueIteratorBase(const Value::ObjectValues::iterator& current);
+    explicit ValueIteratorBase(Value::ObjectValues::iterator const& current);
 
     bool
-    operator==(const SelfType& other) const
+    operator==(SelfType const& other) const
     {
         return isEqual(other);
     }
 
     bool
-    operator!=(const SelfType& other) const
+    operator!=(SelfType const& other) const
     {
         return !isEqual(other);
     }
@@ -527,7 +539,7 @@ public:
 
     /// Return the member name of the referenced Value. "" if it is not an
     /// objectValue.
-    const char*
+    char const*
     memberName() const;
 
 protected:
@@ -541,13 +553,13 @@ protected:
     decrement();
 
     difference_type
-    computeDistance(const SelfType& other) const;
+    computeDistance(SelfType const& other) const;
 
     bool
-    isEqual(const SelfType& other) const;
+    isEqual(SelfType const& other) const;
 
     void
-    copy(const SelfType& other);
+    copy(SelfType const& other);
 
 private:
     Value::ObjectValues::iterator current_;
@@ -565,8 +577,8 @@ class ValueConstIterator : public ValueIteratorBase
 public:
     using size_t = unsigned int;
     using difference_type = int;
-    using reference = const Value&;
-    using pointer = const Value*;
+    using reference = Value const&;
+    using pointer = Value const*;
     using SelfType = ValueConstIterator;
 
     ValueConstIterator() = default;
@@ -574,11 +586,11 @@ public:
 private:
     /*! \internal Use by Value to create an iterator.
      */
-    explicit ValueConstIterator(const Value::ObjectValues::iterator& current);
+    explicit ValueConstIterator(Value::ObjectValues::iterator const& current);
 
 public:
     SelfType&
-    operator=(const ValueIteratorBase& other);
+    operator=(ValueIteratorBase const& other);
 
     SelfType
     operator++(int)
@@ -631,17 +643,17 @@ public:
     using SelfType = ValueIterator;
 
     ValueIterator() = default;
-    ValueIterator(const ValueConstIterator& other);
-    ValueIterator(const ValueIterator& other);
+    ValueIterator(ValueConstIterator const& other);
+    ValueIterator(ValueIterator const& other);
 
 private:
     /*! \internal Use by Value to create an iterator.
      */
-    explicit ValueIterator(const Value::ObjectValues::iterator& current);
+    explicit ValueIterator(Value::ObjectValues::iterator const& current);
 
 public:
     SelfType&
-    operator=(const SelfType& other);
+    operator=(SelfType const& other);
 
     SelfType
     operator++(int)

include/xrpl/json/json_writer.h

@@ -22,6 +22,7 @@
 
 #include <xrpl/json/json_forwards.h>
 #include <xrpl/json/json_value.h>
+
 #include <ostream>
 #include <vector>
 
@@ -38,7 +39,7 @@ public:
     {
     }
     virtual std::string
-    write(const Value& root) = 0;
+    write(Value const& root) = 0;
 };
 
 /** \brief Outputs a Value in <a HREF="http://www.json.org">JSON</a> format
@@ -59,11 +60,11 @@ public:
 
 public:  // overridden from Writer
     std::string
-    write(const Value& root) override;
+    write(Value const& root) override;
 
 private:
     void
-    writeValue(const Value& value);
+    writeValue(Value const& value);
 
     std::string document_;
 };
@@ -100,15 +101,15 @@ public:  // overridden from Writer
      * JSON document that represents the root value.
      */
     std::string
-    write(const Value& root) override;
+    write(Value const& root) override;
 
 private:
     void
-    writeValue(const Value& value);
+    writeValue(Value const& value);
     void
-    writeArrayValue(const Value& value);
+    writeArrayValue(Value const& value);
     bool
-    isMultineArray(const Value& value);
+    isMultineArray(Value const& value);
     void
     pushValue(std::string const& value);
     void
@@ -167,15 +168,15 @@ public:
      * return a value.
      */
     void
-    write(std::ostream& out, const Value& root);
+    write(std::ostream& out, Value const& root);
 
 private:
     void
-    writeValue(const Value& value);
+    writeValue(Value const& value);
     void
-    writeArrayValue(const Value& value);
+    writeArrayValue(Value const& value);
     bool
-    isMultineArray(const Value& value);
+    isMultineArray(Value const& value);
     void
     pushValue(std::string const& value);
     void
@@ -206,12 +207,12 @@ valueToString(double value);
 std::string
 valueToString(bool value);
 std::string
-valueToQuotedString(const char* value);
+valueToQuotedString(char const* value);
 
 /// \brief Output using the StyledStreamWriter.
 /// \see Json::operator>>()
 std::ostream&
-operator<<(std::ostream&, const Value& root);
+operator<<(std::ostream&, Value const& root);
 
 //------------------------------------------------------------------------------
 

include/xrpl/json/to_string.h

@@ -37,7 +37,7 @@ pretty(Value const&);
 
 /** Output using the StyledStreamWriter. @see Json::operator>>(). */
 std::ostream&
-operator<<(std::ostream&, const Value& root);
+operator<<(std::ostream&, Value const& root);
 
 }  // namespace Json
 

include/xrpl/protocol/AMMCore.h

@@ -48,14 +48,6 @@ class STObject;
 class STAmount;
 class Rules;
 
-/** Calculate AMM account ID.
- */
-AccountID
-ammAccountID(
-    std::uint16_t prefix,
-    uint256 const& parentHash,
-    uint256 const& ammID);
-
 /** Calculate Liquidity Provider Token (LPT) Currency.
  */
 Currency

include/xrpl/protocol/AccountID.h

@@ -149,7 +149,7 @@ namespace std {
 template <>
 struct hash<ripple::AccountID> : ripple::AccountID::hasher
 {
-    explicit hash() = default;
+    hash() = default;
 };
 
 }  // namespace std

include/xrpl/protocol/Asset.h

@@ -20,6 +20,7 @@
 #ifndef RIPPLE_PROTOCOL_ASSET_H_INCLUDED
 #define RIPPLE_PROTOCOL_ASSET_H_INCLUDED
 
+#include <xrpl/basics/Number.h>
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/protocol/Issue.h>
 #include <xrpl/protocol/MPTIssue.h>
@@ -27,6 +28,7 @@
 namespace ripple {
 
 class Asset;
+class STAmount;
 
 template <typename TIss>
 concept ValidIssueType =
@@ -92,6 +94,9 @@ public:
     void
     setJson(Json::Value& jv) const;
 
+    STAmount
+    operator()(Number const&) const;
+
     bool
     native() const
     {
@@ -114,6 +119,14 @@ public:
     equalTokens(Asset const& lhs, Asset const& rhs);
 };
 
+inline Json::Value
+to_json(Asset const& asset)
+{
+    Json::Value jv;
+    asset.setJson(jv);
+    return jv;
+}
+
 template <ValidIssueType TIss>
 constexpr bool
 Asset::holds() const
@@ -219,9 +232,6 @@ validJSONAsset(Json::Value const& jv);
 Asset
 assetFromJson(Json::Value const& jv);
 
-Json::Value
-to_json(Asset const& asset);
-
 }  // namespace ripple
 
 #endif  // RIPPLE_PROTOCOL_ASSET_H_INCLUDED

include/xrpl/protocol/Book.h

@@ -22,6 +22,7 @@
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/Issue.h>
+
 #include <boost/utility/base_from_member.hpp>
 
 namespace ripple {
@@ -103,7 +104,7 @@ private:
         boost::base_from_member<std::hash<ripple::AccountID>, 1>;
 
 public:
-    explicit hash() = default;
+    hash() = default;
 
     using value_type = std::size_t;
     using argument_type = ripple::Issue;
@@ -130,7 +131,7 @@ private:
     hasher m_hasher;
 
 public:
-    explicit hash() = default;
+    hash() = default;
 
     using value_type = std::size_t;
     using argument_type = ripple::Book;
@@ -153,7 +154,7 @@ namespace boost {
 template <>
 struct hash<ripple::Issue> : std::hash<ripple::Issue>
 {
-    explicit hash() = default;
+    hash() = default;
 
     using Base = std::hash<ripple::Issue>;
     // VFALCO NOTE broken in vs2012
@@ -163,7 +164,7 @@ struct hash<ripple::Issue> : std::hash<ripple::Issue>
 template <>
 struct hash<ripple::Book> : std::hash<ripple::Book>
 {
-    explicit hash() = default;
+    hash() = default;
 
     using Base = std::hash<ripple::Book>;
     // VFALCO NOTE broken in vs2012

include/xrpl/protocol/ErrorCodes.h

@@ -61,12 +61,10 @@ enum error_code_i {
     rpcAMENDMENT_BLOCKED = 14,
 
     // Networking
-    //@@start network-error-codes
     rpcNO_CLOSED = 15,
     rpcNO_CURRENT = 16,
     rpcNO_NETWORK = 17,
     rpcNOT_SYNCED = 18,
-    //@@end network-error-codes
 
     // Ledger state
     rpcACT_NOT_FOUND = 19,
@@ -123,7 +121,7 @@ enum error_code_i {
     rpcSRC_ACT_MALFORMED = 65,
     rpcSRC_ACT_MISSING = 66,
     rpcSRC_ACT_NOT_FOUND = 67,
-    // unused                  68,
+    rpcDELEGATE_ACT_NOT_FOUND = 68,
     rpcSRC_CUR_MALFORMED = 69,
     rpcSRC_ISR_MALFORMED = 70,
     rpcSTREAM_MALFORMED = 71,

include/xrpl/protocol/Feature.h

@@ -21,7 +21,9 @@
 #define RIPPLE_PROTOCOL_FEATURE_H_INCLUDED
 
 #include <xrpl/basics/base_uint.h>
+
 #include <boost/container/flat_map.hpp>
+
 #include <array>
 #include <bitset>
 #include <map>
@@ -33,35 +35,39 @@
  *
  * Steps required to add new features to the code:
  *
- * 1) In this file, increment `numFeatures` and add a uint256 declaration
- *    for the feature at the bottom
- * 2) Add a uint256 definition for the feature to the corresponding source
- *    file (Feature.cpp). Use `registerFeature` to create the feature with
- *    the feature's name, `Supported::no`, and `VoteBehavior::DefaultNo`. This
- *    should be the only place the feature's name appears in code as a string.
- * 3) Use the uint256 as the parameter to `view.rules.enabled()` to
- *    control flow into new code that this feature limits.
- * 4) If the feature development is COMPLETE, and the feature is ready to be
- *    SUPPORTED, change the `registerFeature` parameter to Supported::yes.
- * 5) When the feature is ready to be ENABLED, change the `registerFeature`
- *    parameter to `VoteBehavior::DefaultYes`.
- * In general, any newly supported amendments (`Supported::yes`) should have
- * a `VoteBehavior::DefaultNo` for at least one full release cycle. High
- * priority bug fixes can be an exception to this rule of thumb.
+ * 1) Add the appropriate XRPL_FEATURE or XRPL_FIX macro definition for the
+ *    feature to features.macro with the feature's name, `Supported::no`, and
+ *    `VoteBehavior::DefaultNo`.
+ *
+ * 2) Use the generated variable name as the parameter to `view.rules.enabled()`
+ *    to control flow into new code that this feature limits. (featureName or
+ *    fixName)
+ *
+ * 3) If the feature development is COMPLETE, and the feature is ready to be
+ *    SUPPORTED, change the macro parameter in features.macro to Supported::yes.
+ *
+ * 4) In general, any newly supported amendments (`Supported::yes`) should have
+ *    a `VoteBehavior::DefaultNo` indefinitely so that external governance can
+ *    make the decision on when to activate it. High priority bug fixes can be
+ *    an exception to this rule. In such cases, ensure the fix has been
+ *    clearly communicated to the community using appropriate channels,
+ *    then change the macro parameter in features.macro to
+ *    `VoteBehavior::DefaultYes`. The communication process is beyond
+ *    the scope of these instructions.
+ *
  *
  * When a feature has been enabled for several years, the conditional code
  * may be removed, and the feature "retired". To retire a feature:
- * 1) Remove the uint256 declaration from this file.
- * 2) MOVE the uint256 definition in Feature.cpp to the "retired features"
- *    section at the end of the file.
- * 3) CHANGE the name of the variable to start with "retired".
- * 4) CHANGE the parameters of the `registerFeature` call to `Supported::yes`
- *    and `VoteBehavior::DefaultNo`.
+ *
+ * 1) MOVE the macro definition in features.macro to the "retired features"
+ *    section at the end of the file, and change the macro to XRPL_RETIRE.
+ *
  * The feature must remain registered and supported indefinitely because it
- * still exists in the ledger, but there is no need to vote for it because
- * there's nothing to vote for. If it is removed completely from the code, any
- * instances running that code will get amendment blocked. Removing the
- * feature from the ledger is beyond the scope of these instructions.
+ * may exist in the Amendments object on ledger. There is no need to vote
+ * for it because there's nothing to vote for. If the feature definition is
+ * removed completely from the code, any instances running that code will get
+ * amendment blocked. Removing the feature from the ledger is beyond the scope
+ * of these instructions.
  *
  */
 
@@ -76,11 +82,32 @@ allAmendments();
 
 namespace detail {
 
+#pragma push_macro("XRPL_FEATURE")
+#undef XRPL_FEATURE
+#pragma push_macro("XRPL_FIX")
+#undef XRPL_FIX
+#pragma push_macro("XRPL_RETIRE")
+#undef XRPL_RETIRE
+
+#define XRPL_FEATURE(name, supported, vote) +1
+#define XRPL_FIX(name, supported, vote) +1
+#define XRPL_RETIRE(name) +1
+
 // This value SHOULD be equal to the number of amendments registered in
 // Feature.cpp. Because it's only used to reserve storage, and determine how
 // large to make the FeatureBitset, it MAY be larger. It MUST NOT be less than
 // the actual number of amendments. A LogicError on startup will verify this.
-static constexpr std::size_t numFeatures = 113;
+static constexpr std::size_t numFeatures =
+    (0 +
+#include <xrpl/protocol/detail/features.macro>
+    );
+
+#undef XRPL_RETIRE
+#pragma pop_macro("XRPL_RETIRE")
+#undef XRPL_FIX
+#pragma pop_macro("XRPL_FIX")
+#undef XRPL_FEATURE
+#pragma pop_macro("XRPL_FEATURE")
 
 /** Amendments that this server supports and the default voting behavior.
    Whether they are enabled depends on the Rules defined in the validated
@@ -320,12 +347,17 @@ foreachFeature(FeatureBitset bs, F&& f)
 #undef XRPL_FEATURE
 #pragma push_macro("XRPL_FIX")
 #undef XRPL_FIX
+#pragma push_macro("XRPL_RETIRE")
+#undef XRPL_RETIRE
 
 #define XRPL_FEATURE(name, supported, vote) extern uint256 const feature##name;
 #define XRPL_FIX(name, supported, vote) extern uint256 const fix##name;
+#define XRPL_RETIRE(name)
 
 #include <xrpl/protocol/detail/features.macro>
 
+#undef XRPL_RETIRE
+#pragma pop_macro("XRPL_RETIRE")
 #undef XRPL_FIX
 #pragma pop_macro("XRPL_FIX")
 #undef XRPL_FEATURE

include/xrpl/protocol/FeeUnits.h

@@ -23,6 +23,7 @@
 #include <xrpl/beast/utility/Zero.h>
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/json/json_value.h>
+
 #include <boost/multiprecision/cpp_int.hpp>
 #include <boost/operators.hpp>
 
@@ -335,7 +336,7 @@ public:
 // Output Fees as just their numeric value.
 template <class Char, class Traits, class UnitTag, class T>
 std::basic_ostream<Char, Traits>&
-operator<<(std::basic_ostream<Char, Traits>& os, const TaggedFee<UnitTag, T>& q)
+operator<<(std::basic_ostream<Char, Traits>& os, TaggedFee<UnitTag, T> const& q)
 {
     return os << q.value();
 }

include/xrpl/protocol/HashPrefix.h

@@ -21,6 +21,7 @@
 #define RIPPLE_PROTOCOL_HASHPREFIX_H_INCLUDED
 
 #include <xrpl/beast/hash/hash_append.h>
+
 #include <cstdint>
 
 namespace ripple {

include/xrpl/protocol/IOUAmount.h

@@ -23,10 +23,11 @@
 #include <xrpl/basics/LocalValue.h>
 #include <xrpl/basics/Number.h>
 #include <xrpl/beast/utility/Zero.h>
+
 #include <boost/operators.hpp>
+
 #include <cstdint>
 #include <string>
-#include <utility>
 
 namespace ripple {
 

include/xrpl/protocol/Import.h

@@ -21,10 +21,12 @@
 #define RIPPLE_PROTOCOL_IMPORT_H_INCLUDED
 
 #include <xrpld/app/misc/Manifest.h>
+
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/StringUtilities.h>
 #include <xrpl/basics/base64.h>
 #include <xrpl/json/json_reader.h>
+
 #include <charconv>
 
 namespace ripple {
@@ -85,7 +87,7 @@ syntaxCheckProof(
                 << "XPOP.transaction.proof list should be exactly 16 entries";
             return false;
         }
-        for (const auto& entry : proof)
+        for (auto const& entry : proof)
         {
             if (entry.isString())
             {
@@ -130,7 +132,7 @@ syntaxCheckProof(
             return syntaxCheckProof(proof["children"], j, depth + 1);
         }
 
-        for (const auto& branch : proof.getMemberNames())
+        for (auto const& branch : proof.getMemberNames())
         {
             if (branch.size() != 1 || !isHex(branch))
             {
@@ -140,7 +142,7 @@ syntaxCheckProof(
                 return false;
             }
 
-            const auto& node = proof[branch];
+            auto const& node = proof[branch];
             if (!node.isObject() || !node["hash"].isString() ||
                 node["hash"].asString().size() != 64 ||
                 !node["key"].isString() ||
@@ -334,9 +336,9 @@ syntaxCheckXPOP(Blob const& blob, beast::Journal const& j)
             return {};
         }
 
-        for (const auto& key : xpop["validation"]["data"].getMemberNames())
+        for (auto const& key : xpop["validation"]["data"].getMemberNames())
         {
-            const auto& value = xpop["validation"]["data"][key];
+            auto const& value = xpop["validation"]["data"][key];
             if (!isBase58(key) || !value.isString() || !isHex(value.asString()))
             {
                 JLOG(j.warn()) << "XPOP.validation.data entry has wrong format "
@@ -347,9 +349,9 @@ syntaxCheckXPOP(Blob const& blob, beast::Journal const& j)
         }
 
         uint32_t found = 0;
-        for (const auto& key : xpop["validation"]["unl"].getMemberNames())
+        for (auto const& key : xpop["validation"]["unl"].getMemberNames())
         {
-            const auto& value = xpop["validation"]["unl"][key];
+            auto const& value = xpop["validation"]["unl"][key];
             if (key == "public_key")
             {
                 if (!value.isString() || !isHex(value.asString()))

include/xrpl/protocol/Indexes.h

@@ -316,6 +316,10 @@ amm(Asset const& issue1, Asset const& issue2) noexcept;
 Keylet
 amm(uint256 const& amm) noexcept;
 
+/** A keylet for Delegate object */
+Keylet
+delegate(AccountID const& account, AccountID const& authorizedAccount) noexcept;
+
 Keylet
 bridge(STXChainBridge const& bridge, STXChainBridge::ChainType chainType);
 
@@ -367,6 +371,15 @@ mptoken(uint256 const& mptokenKey)
 Keylet
 mptoken(uint256 const& issuanceKey, AccountID const& holder) noexcept;
 
+Keylet
+vault(AccountID const& owner, std::uint32_t seq) noexcept;
+
+inline Keylet
+vault(uint256 const& vaultKey)
+{
+    return {ltVAULT, vaultKey};
+}
+
 Keylet
 permissionedDomain(AccountID const& account, std::uint32_t seq) noexcept;
 

include/xrpl/protocol/KnownFormats.h

@@ -23,7 +23,9 @@
 #include <xrpl/basics/contract.h>
 #include <xrpl/beast/type_name.h>
 #include <xrpl/protocol/SOTemplate.h>
+
 #include <boost/container/flat_map.hpp>
+
 #include <algorithm>
 #include <forward_list>