Squashed 'src/ripple/rocksdb/rocksdb/' content from commit 56589ab

git-subtree-dir: src/ripple/rocksdb/rocksdb
git-subtree-split: 56589ab81f6827ff7402e31b24a6d548f29a524f

db/table_cache.cc

@@ -0,0 +1,173 @@
+//  Copyright (c) 2013, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under the BSD-style license found in the
+//  LICENSE file in the root directory of this source tree. An additional grant
+//  of patent rights can be found in the PATENTS file in the same directory.
+//
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#include "db/table_cache.h"
+
+#include "db/filename.h"
+
+#include "rocksdb/statistics.h"
+#include "rocksdb/table.h"
+#include "util/coding.h"
+#include "util/stop_watch.h"
+
+namespace rocksdb {
+
+static void DeleteEntry(const Slice& key, void* value) {
+  TableReader* table_reader = reinterpret_cast<TableReader*>(value);
+  delete table_reader;
+}
+
+static void UnrefEntry(void* arg1, void* arg2) {
+  Cache* cache = reinterpret_cast<Cache*>(arg1);
+  Cache::Handle* h = reinterpret_cast<Cache::Handle*>(arg2);
+  cache->Release(h);
+}
+
+TableCache::TableCache(const std::string& dbname,
+                       const Options* options,
+                       const EnvOptions& storage_options,
+                       int entries)
+    : env_(options->env),
+      dbname_(dbname),
+      options_(options),
+      storage_options_(storage_options),
+      cache_(
+        NewLRUCache(entries, options->table_cache_numshardbits,
+                    options->table_cache_remove_scan_count_limit)) {
+}
+
+TableCache::~TableCache() {
+}
+
+Status TableCache::FindTable(const EnvOptions& toptions,
+                             uint64_t file_number, uint64_t file_size,
+                             Cache::Handle** handle, bool* table_io,
+                             const bool no_io) {
+  Status s;
+  char buf[sizeof(file_number)];
+  EncodeFixed64(buf, file_number);
+  Slice key(buf, sizeof(buf));
+  *handle = cache_->Lookup(key);
+  if (*handle == nullptr) {
+    if (no_io) { // Dont do IO and return a not-found status
+      return Status::Incomplete("Table not found in table_cache, no_io is set");
+    }
+    if (table_io != nullptr) {
+      *table_io = true;    // we had to do IO from storage
+    }
+    std::string fname = TableFileName(dbname_, file_number);
+    unique_ptr<RandomAccessFile> file;
+    unique_ptr<TableReader> table_reader;
+    s = env_->NewRandomAccessFile(fname, &file, toptions);
+    RecordTick(options_->statistics, NO_FILE_OPENS);
+    if (s.ok()) {
+      if (options_->advise_random_on_open) {
+        file->Hint(RandomAccessFile::RANDOM);
+      }
+      StopWatch sw(env_, options_->statistics, TABLE_OPEN_IO_MICROS);
+      s = options_->table_factory->GetTableReader(*options_, toptions,
+                                                  std::move(file), file_size,
+                                                  &table_reader);
+    }
+
+    if (!s.ok()) {
+      assert(table_reader == nullptr);
+      RecordTick(options_->statistics, NO_FILE_ERRORS);
+      // We do not cache error results so that if the error is transient,
+      // or somebody repairs the file, we recover automatically.
+    } else {
+      assert(file.get() == nullptr);
+      *handle = cache_->Insert(key, table_reader.release(), 1, &DeleteEntry);
+    }
+  }
+  return s;
+}
+
+Iterator* TableCache::NewIterator(const ReadOptions& options,
+                                  const EnvOptions& toptions,
+                                  uint64_t file_number,
+                                  uint64_t file_size,
+                                  TableReader** table_reader_ptr,
+                                  bool for_compaction) {
+  if (table_reader_ptr != nullptr) {
+    *table_reader_ptr = nullptr;
+  }
+
+  Cache::Handle* handle = nullptr;
+  Status s = FindTable(toptions, file_number, file_size, &handle,
+                       nullptr, options.read_tier == kBlockCacheTier);
+  if (!s.ok()) {
+    return NewErrorIterator(s);
+  }
+
+  TableReader* table_reader =
+    reinterpret_cast<TableReader*>(cache_->Value(handle));
+  Iterator* result = table_reader->NewIterator(options);
+  result->RegisterCleanup(&UnrefEntry, cache_.get(), handle);
+  if (table_reader_ptr != nullptr) {
+    *table_reader_ptr = table_reader;
+  }
+
+  if (for_compaction) {
+    table_reader->SetupForCompaction();
+  }
+
+  return result;
+}
+
+Status TableCache::Get(const ReadOptions& options,
+                       uint64_t file_number,
+                       uint64_t file_size,
+                       const Slice& k,
+                       void* arg,
+                       bool (*saver)(void*, const Slice&, const Slice&, bool),
+                       bool* table_io,
+                       void (*mark_key_may_exist)(void*)) {
+  Cache::Handle* handle = nullptr;
+  Status s = FindTable(storage_options_, file_number, file_size,
+                       &handle, table_io,
+                       options.read_tier == kBlockCacheTier);
+  if (s.ok()) {
+    TableReader* t =
+      reinterpret_cast<TableReader*>(cache_->Value(handle));
+    s = t->Get(options, k, arg, saver, mark_key_may_exist);
+    cache_->Release(handle);
+  } else if (options.read_tier && s.IsIncomplete()) {
+    // Couldnt find Table in cache but treat as kFound if no_io set
+    (*mark_key_may_exist)(arg);
+    return Status::OK();
+  }
+  return s;
+}
+
+bool TableCache::PrefixMayMatch(const ReadOptions& options,
+                                uint64_t file_number,
+                                uint64_t file_size,
+                                const Slice& internal_prefix,
+                                bool* table_io) {
+  Cache::Handle* handle = nullptr;
+  Status s = FindTable(storage_options_, file_number,
+                       file_size, &handle, table_io);
+  bool may_match = true;
+  if (s.ok()) {
+    TableReader* t =
+      reinterpret_cast<TableReader*>(cache_->Value(handle));
+    may_match = t->PrefixMayMatch(internal_prefix);
+    cache_->Release(handle);
+  }
+  return may_match;
+}
+
+void TableCache::Evict(uint64_t file_number) {
+  char buf[sizeof(file_number)];
+  EncodeFixed64(buf, file_number);
+  cache_->Erase(Slice(buf, sizeof(buf)));
+}
+
+}  // namespace rocksdb