Abstract minimum maxmempool to maxmempoolMinimumBytes function (in txmempool)

Author: luke-jr

src/rpc/mempool.cpp

@@ -394,7 +394,7 @@ static RPCHelpMan maxmempool()
     CTxMemPool& mempool = EnsureAnyMemPool(request.context);
     LOCK(mempool.cs);
 
-    int64_t nMempoolSizeMin = mempool.m_opts.limits.descendant_size_vbytes * 40;
+    int64_t nMempoolSizeMin = maxmempoolMinimumBytes(mempool.m_opts.limits.descendant_size_vbytes);
     if (nMempoolSizeMax < 0 || nMempoolSizeMax < nMempoolSizeMin)
         throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("MaxMempool size %d is too small", nSize));
     mempool.m_opts.max_size_bytes = nSize;

src/txmempool.cpp

@@ -401,7 +401,7 @@ void CTxMemPoolEntry::UpdateAncestorState(int32_t modifySize, CAmount modifyFee,
 static CTxMemPool::Options&& Flatten(CTxMemPool::Options&& opts, bilingual_str& error)
 {
     opts.check_ratio = std::clamp<int>(opts.check_ratio, 0, 1'000'000);
-    int64_t descendant_limit_bytes = opts.limits.descendant_size_vbytes * 40;
+    int64_t descendant_limit_bytes = maxmempoolMinimumBytes(opts.limits.descendant_size_vbytes);
     if (opts.max_size_bytes < 0 || opts.max_size_bytes < descendant_limit_bytes) {
         error = strprintf(_("-maxmempool must be at least %d MB"), std::ceil(descendant_limit_bytes / 1'000'000.0));
     }

src/txmempool.h

@@ -48,6 +48,10 @@ struct bilingual_str;
 /** Fake height value used in Coin to signify they are only in the memory pool (since 0.8) */
 static const uint32_t MEMPOOL_HEIGHT = 0x7FFFFFFF;
 
+inline int64_t maxmempoolMinimumBytes(const int64_t descendant_size_vbytes) {
+    return descendant_size_vbytes * 40;
+}
+
 /**
  * Test whether the LockPoints height and time are still valid on the current chain
  */