From 8aa21e119b0289e5b5b6fb02e275690a284073f2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C5=91rinc?= <pap.lorinc@gmail.com>
Date: Thu, 23 Apr 2026 16:19:26 +0200
Subject: [PATCH] kernel, node: colocate dbcache bounds

Keep the total database cache bounds with `kernel::CacheSizes` so node and Kernel callers validate against the same range.
---
 src/kernel/caches.h       | 5 +++++
 src/node/caches.cpp       | 6 +-----
 src/node/caches.h         | 2 --
 src/test/caches_tests.cpp | 1 +
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/kernel/caches.h b/src/kernel/caches.h
index ad65b165c23..6bc10c92355 100644
--- a/src/kernel/caches.h
+++ b/src/kernel/caches.h
@@ -9,7 +9,12 @@
 
 #include <algorithm>
 #include <cstdint>
+#include <limits>
 
+//! Minimum total database cache (bytes)
+static constexpr uint64_t MIN_DBCACHE_BYTES{4_MiB};
+//! Maximum total database cache on current architecture (bytes)
+static constexpr uint64_t MAX_DBCACHE_BYTES{sizeof(void*) == 4 ? 1_GiB : std::numeric_limits<uint64_t>::max()};
 //! Suggested default amount of cache reserved for the kernel (bytes)
 static constexpr uint64_t DEFAULT_KERNEL_CACHE{450_MiB};
 //! Default LevelDB write batch size
diff --git a/src/node/caches.cpp b/src/node/caches.cpp
index 37b674fa918..c25b3e9a9a7 100644
--- a/src/node/caches.cpp
+++ b/src/node/caches.cpp
@@ -18,7 +18,6 @@
 
 #include <algorithm>
 #include <cstdint>
-#include <limits>
 #include <string>
 
 // Unlike for the UTXO database, for the txindex scenario the leveldb cache make
@@ -29,8 +28,6 @@ static constexpr uint64_t MAX_TX_INDEX_CACHE{1_GiB};
 static constexpr uint64_t MAX_FILTER_INDEX_CACHE{1_GiB};
 //! Max memory allocated to tx spenderindex DB specific cache in bytes.
 static constexpr uint64_t MAX_TXOSPENDER_INDEX_CACHE{1_GiB};
-//! Maximum dbcache size on 32-bit systems.
-static constexpr uint64_t MAX_32BIT_DBCACHE{1_GiB};
 //! Larger default dbcache on 64-bit systems with enough RAM.
 static constexpr uint64_t HIGH_DEFAULT_DBCACHE{1_GiB};
 //! Minimum detected RAM required for HIGH_DEFAULT_DBCACHE.
@@ -52,8 +49,7 @@ uint64_t CalculateDbCacheBytes(const ArgsManager& args)
     if (auto db_cache{args.GetIntArg("-dbcache")}) {
         if (*db_cache < 0) db_cache = 0;
         const uint64_t db_cache_bytes{SaturatingLeftShift<uint64_t>(*db_cache, 20)};
-        constexpr uint64_t max_db_cache{sizeof(void*) == 4 ? MAX_32BIT_DBCACHE : std::numeric_limits<uint64_t>::max()};
-        return std::max<uint64_t>(MIN_DBCACHE_BYTES, std::min<uint64_t>(db_cache_bytes, max_db_cache));
+        return std::max(MIN_DBCACHE_BYTES, std::min(db_cache_bytes, MAX_DBCACHE_BYTES));
     }
     return GetDefaultDBCache();
 }
diff --git a/src/node/caches.h b/src/node/caches.h
index 8bfd499b9ea..756dfa37874 100644
--- a/src/node/caches.h
+++ b/src/node/caches.h
@@ -14,8 +14,6 @@
 
 class ArgsManager;
 
-//! min. -dbcache (bytes)
-static constexpr uint64_t MIN_DBCACHE_BYTES{4_MiB};
 //! -dbcache default (bytes)
 static constexpr uint64_t DEFAULT_DB_CACHE{DEFAULT_KERNEL_CACHE};
 //! Reserved non-dbcache memory usage.
diff --git a/src/test/caches_tests.cpp b/src/test/caches_tests.cpp
index 8144aac00d5..15820a79746 100644
--- a/src/test/caches_tests.cpp
+++ b/src/test/caches_tests.cpp
@@ -2,6 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or https://opensource.org/license/mit.
 
+#include <kernel/caches.h>
 #include <node/caches.h>
 #include <util/byte_units.h>