From c83bfe19878bf4b7b565a35360495cea7533fd4e Mon Sep 17 00:00:00 2001
From: tequ <git@tequ.dev>
Date: Mon, 6 Oct 2025 13:49:07 +0900
Subject: [PATCH] add slot_type API

---
 src/ripple/app/hook/HookAPI.h          |  3 ++-
 src/ripple/app/hook/impl/HookAPI.cpp   | 33 ++++++++++++++++++++++++-
 src/ripple/app/hook/impl/applyHook.cpp | 34 ++++++++------------------
 3 files changed, 44 insertions(+), 26 deletions(-)

diff --git a/src/ripple/app/hook/HookAPI.h b/src/ripple/app/hook/HookAPI.h
index 05c3f1cab..96f2d6df2 100644
--- a/src/ripple/app/hook/HookAPI.h
+++ b/src/ripple/app/hook/HookAPI.h
@@ -254,7 +254,8 @@ public:
     slot_subfield(uint32_t parent_slot, uint32_t field_id, uint32_t new_slot)
         const;
 
-    // slot_type
+    Expected<std::variant<STBase, STAmount>, HookReturnCode>
+    slot_type(uint32_t slot_no, uint32_t flags) const;
 
     Expected<uint64_t, HookReturnCode>
     slot_float(uint32_t slot_no) const;
diff --git a/src/ripple/app/hook/impl/HookAPI.cpp b/src/ripple/app/hook/impl/HookAPI.cpp
index f2f8f0a56..fc1cd1dd5 100644
--- a/src/ripple/app/hook/impl/HookAPI.cpp
+++ b/src/ripple/app/hook/impl/HookAPI.cpp
@@ -2353,7 +2353,38 @@ HookAPI::slot_subfield(
     }
 }
 
-// slot_type
+Expected<std::variant<STBase, STAmount>, HookReturnCode>
+HookAPI::slot_type(uint32_t slot_no, uint32_t flags) const
+{
+    if (hookCtx.slot.find(slot_no) == hookCtx.slot.end())
+        return Unexpected(DOESNT_EXIST);
+
+    if (hookCtx.slot[slot_no].entry == 0)
+        return Unexpected(INTERNAL_ERROR);
+    try
+    {
+        ripple::STBase& obj = const_cast<ripple::STBase&>(
+            *hookCtx.slot[slot_no].entry);  //.downcast<ripple::STBase>();
+        if (flags == 0)
+            return obj;
+
+        // this flag is for use with an amount field to determine if the amount
+        // is native (xrp)
+        if (flags == 1)
+        {
+            if (obj.getSType() != STI_AMOUNT)
+                return Unexpected(NOT_AN_AMOUNT);
+            return const_cast<ripple::STBase&>(*hookCtx.slot[slot_no].entry)
+                .downcast<ripple::STAmount>();
+        }
+
+        return Unexpected(INVALID_ARGUMENT);
+    }
+    catch (const std::bad_cast& e)
+    {
+        return Unexpected(INTERNAL_ERROR);
+    }
+}
 
 Expected<uint64_t, HookReturnCode>
 HookAPI::slot_float(uint32_t slot_no) const
diff --git a/src/ripple/app/hook/impl/applyHook.cpp b/src/ripple/app/hook/impl/applyHook.cpp
index 50466e2e9..dc4845b37 100644
--- a/src/ripple/app/hook/impl/applyHook.cpp
+++ b/src/ripple/app/hook/impl/applyHook.cpp
@@ -2131,34 +2131,20 @@ DEFINE_HOOK_FUNCTION(int64_t, slot_type, uint32_t slot_no, uint32_t flags)
     HOOK_SETUP();  // populates memory_ctx, memory, memory_length, applyCtx,
                    // hookCtx on current stack
 
-    if (hookCtx.slot.find(slot_no) == hookCtx.slot.end())
-        return DOESNT_EXIST;
+    hook::HookAPI api(hookCtx);
+    auto const result = api.slot_type(slot_no, flags);
+    if (!result)
+        return result.error();
 
-    if (hookCtx.slot[slot_no].entry == 0)
-        return INTERNAL_ERROR;
-    try
+    if (flags == 0)
     {
-        ripple::STBase& obj = const_cast<ripple::STBase&>(
-            *hookCtx.slot[slot_no].entry);  //.downcast<ripple::STBase>();
-        if (flags == 0)
-            return obj.getFName().fieldCode;
-
-        // this flag is for use with an amount field to determine if the amount
-        // is native (xrp)
-        if (flags == 1)
-        {
-            if (obj.getSType() != STI_AMOUNT)
-                return NOT_AN_AMOUNT;
-            return const_cast<ripple::STBase&>(*hookCtx.slot[slot_no].entry)
-                .downcast<ripple::STAmount>()
-                .native();
-        }
-
-        return INVALID_ARGUMENT;
+        auto const base = std::get<0>(*result);
+        return base.getFName().fieldCode;
     }
-    catch (const std::bad_cast& e)
+    else
     {
-        return INTERNAL_ERROR;
+        auto const amount = std::get<1>(*result);
+        return amount.native();
     }
 
     HOOK_TEARDOWN();