Cache size optimizations

src/init.cpp

@@ -236,7 +236,6 @@ std::string HelpMessage()
         "  -gen=0                 " + _("Don't generate coins") + "\n" +
         "  -datadir=<dir>         " + _("Specify data directory") + "\n" +
         "  -dbcache=<n>           " + _("Set database cache size in megabytes (default: 25)") + "\n" +
-        "  -dblogsize=<n>         " + _("Set database disk log size in megabytes (default: 100)") + "\n" +
         "  -timeout=<n>           " + _("Specify connection timeout in milliseconds (default: 5000)") + "\n" +
         "  -proxy=<ip:port>       " + _("Connect through socks proxy") + "\n" +
         "  -socks=<n>             " + _("Select the version of socks proxy to use (4-5, default: 5)") + "\n" +
@@ -651,11 +650,23 @@ bool AppInit2()
         return InitError(msg);
     }
 
+    // cache size calculations
+    size_t nTotalCache = GetArg("-dbcache", 25) << 20;
+    if (nTotalCache < (1 << 22))
+        nTotalCache = (1 << 22); // total cache cannot be less than 4 MiB
+    size_t nBlockTreeDBCache = nTotalCache / 8;
+    if (nBlockTreeDBCache > (1 << 21))
+        nBlockTreeDBCache = (1 << 21); // block tree db cache shouldn't be larger than 2 MiB
+    nTotalCache -= nBlockTreeDBCache;
+    size_t nCoinDBCache = nTotalCache / 2; // use half of the remaining cache for coindb cache
+    nTotalCache -= nCoinDBCache;
+    nCoinCacheSize = nTotalCache / 300; // coins in memory require around 300 bytes
+
     uiInterface.InitMessage(_("Loading block index..."));
     printf("Loading block index...\n");
     nStart = GetTimeMillis();
-    pblocktree = new CBlockTreeDB();
+    pblocktree = new CBlockTreeDB(nBlockTreeDBCache);
-    pcoinsdbview = new CCoinsViewDB();
+    pcoinsdbview = new CCoinsViewDB(nCoinDBCache);
     pcoinsTip = new CCoinsViewCache(*pcoinsdbview);
 
     if (!LoadBlockIndex())

src/leveldb.cpp

@@ -12,22 +12,22 @@
 
 #include <boost/filesystem.hpp>
 
-static leveldb::Options GetOptions() {
+static leveldb::Options GetOptions(size_t nCacheSize) {
     leveldb::Options options;
-    int nCacheSizeMB = GetArg("-dbcache", 25);
+    options.block_cache = leveldb::NewLRUCache(nCacheSize / 2);
-    options.block_cache = leveldb::NewLRUCache(nCacheSizeMB * 1048576);
+    options.write_buffer_size = nCacheSize / 4; // up to two write buffers may be held in memory simultaneously
     options.filter_policy = leveldb::NewBloomFilterPolicy(10);
     options.compression = leveldb::kNoCompression;
     return options;
 }
 
-CLevelDB::CLevelDB(const boost::filesystem::path &path, bool fMemory) {
+CLevelDB::CLevelDB(const boost::filesystem::path &path, size_t nCacheSize, bool fMemory) {
     penv = NULL;
     readoptions.verify_checksums = true;
     iteroptions.verify_checksums = true;
     iteroptions.fill_cache = false;
     syncoptions.sync = true;
-    options = GetOptions();
+    options = GetOptions(nCacheSize);
     options.create_if_missing = true;
     if (fMemory) {
         penv = leveldb::NewMemEnv(leveldb::Env::Default());

src/leveldb.h

@@ -69,7 +69,7 @@ private:
     leveldb::DB *pdb;
 
 public:
-    CLevelDB(const boost::filesystem::path &path, bool fMemory = false);
+    CLevelDB(const boost::filesystem::path &path, size_t nCacheSize, bool fMemory = false);
     ~CLevelDB();
 
     template<typename K, typename V> bool Read(const K& key, V& value) {

src/main.cpp

@@ -41,6 +41,7 @@ CBlockIndex* pindexBest = NULL;
 set<CBlockIndex*, CBlockIndexWorkComparator> setBlockIndexValid; // may contain all CBlockIndex*'s that have validness >=BLOCK_VALID_TRANSACTIONS, and must contain those who aren't failed
 int64 nTimeBestReceived = 0;
 bool fImporting = false;
+unsigned int nCoinCacheSize = 5000;
 
 CMedianFilter<int> cPeerBlockCounts(5, 0); // Amount of blocks that other nodes claim to have
 
@@ -1735,7 +1736,7 @@ bool SetBestChain(CBlockIndex* pindexNew)
 
     // Make sure it's successfully written to disk before changing memory structure
     bool fIsInitialDownload = IsInitialBlockDownload();
-    if (!fIsInitialDownload || view.GetCacheSize()>5000) {
+    if (!fIsInitialDownload || view.GetCacheSize() > nCoinCacheSize) {
         FlushBlockFile();
         pblocktree->Sync();
         if (!view.Flush())

src/main.h

@@ -88,6 +88,7 @@ extern CCriticalSection cs_setpwalletRegistered;
 extern std::set<CWallet*> setpwalletRegistered;
 extern unsigned char pchMessageStart[4];
 extern bool fImporting;
+extern unsigned int nCoinCacheSize;
 
 // Settings
 extern int64 nTransactionFee;

src/txdb.cpp

@@ -19,7 +19,7 @@ void static BatchWriteHashBestChain(CLevelDBBatch &batch, const uint256 &hash) {
     batch.Write('B', hash);
 }
 
-CCoinsViewDB::CCoinsViewDB(bool fMemory) : db(GetDataDir() / "coins", fMemory) {
+CCoinsViewDB::CCoinsViewDB(size_t nCacheSize, bool fMemory) : db(GetDataDir() / "coins", nCacheSize, fMemory) {
 }
 
 bool CCoinsViewDB::GetCoins(uint256 txid, CCoins &coins) { 
@@ -64,7 +64,7 @@ bool CCoinsViewDB::BatchWrite(const std::map<uint256, CCoins> &mapCoins, CBlockI
     return db.WriteBatch(batch);
 }
 
-CBlockTreeDB::CBlockTreeDB(bool fMemory) : CLevelDB(GetDataDir() / "blktree", fMemory) {
+CBlockTreeDB::CBlockTreeDB(size_t nCacheSize, bool fMemory) : CLevelDB(GetDataDir() / "blktree", nCacheSize, fMemory) {
 }
 
 bool CBlockTreeDB::WriteBlockIndex(const CDiskBlockIndex& blockindex)

src/txdb.h

@@ -14,7 +14,7 @@ class CCoinsViewDB : public CCoinsView
 protected:
     CLevelDB db;
 public:
-    CCoinsViewDB(bool fMemory = false);
+    CCoinsViewDB(size_t nCacheSize, bool fMemory = false);
 
     bool GetCoins(uint256 txid, CCoins &coins);
     bool SetCoins(uint256 txid, const CCoins &coins);
@@ -29,7 +29,7 @@ public:
 class CBlockTreeDB : public CLevelDB
 {
 public:
-    CBlockTreeDB(bool fMemory = false);
+    CBlockTreeDB(size_t nCacheSize, bool fMemory = false);
 private:
     CBlockTreeDB(const CBlockTreeDB&);
     void operator=(const CBlockTreeDB&);