core/rawdb, core/state/snapshot: runtime snapshot generation

eth/backend.go

@@ -127,7 +127,8 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 		config.Miner.GasPrice = new(big.Int).Set(DefaultConfig.Miner.GasPrice)
 	}
 	if config.NoPruning && config.TrieDirtyCache > 0 {
-		config.TrieCleanCache += config.TrieDirtyCache
+		config.TrieCleanCache += config.TrieDirtyCache * 3 / 5
+		config.SnapshotCache += config.TrieDirtyCache * 3 / 5
 		config.TrieDirtyCache = 0
 	}
 	log.Info("Allocated trie memory caches", "clean", common.StorageSize(config.TrieCleanCache)*1024*1024, "dirty", common.StorageSize(config.TrieDirtyCache)*1024*1024)
@@ -184,6 +185,7 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 			TrieDirtyLimit:      config.TrieDirtyCache,
 			TrieDirtyDisabled:   config.NoPruning,
 			TrieTimeLimit:       config.TrieTimeout,
+			SnapshotLimit:       config.SnapshotCache,
 		}
 	)
 	eth.blockchain, err = core.NewBlockChain(chainDb, cacheConfig, chainConfig, eth.engine, vmConfig, eth.shouldPreserve)
@@ -204,7 +206,7 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 	eth.txPool = core.NewTxPool(config.TxPool, chainConfig, eth.blockchain)
 
 	// Permit the downloader to use the trie cache allowance during fast sync
-	cacheLimit := cacheConfig.TrieCleanLimit + cacheConfig.TrieDirtyLimit
+	cacheLimit := cacheConfig.TrieCleanLimit + cacheConfig.TrieDirtyLimit + cacheConfig.SnapshotLimit
 	checkpoint := config.Checkpoint
 	if checkpoint == nil {
 		checkpoint = params.TrustedCheckpoints[genesisHash]

eth/config.go

@@ -50,6 +50,7 @@ var DefaultConfig = Config{
 	TrieCleanCache:     256,
 	TrieDirtyCache:     256,
 	TrieTimeout:        60 * time.Minute,
+	SnapshotCache:      256,
 	Miner: miner.Config{
 		GasFloor: 8000000,
 		GasCeil:  8000000,
@@ -125,6 +126,7 @@ type Config struct {
 	TrieCleanCache int
 	TrieDirtyCache int
 	TrieTimeout    time.Duration
+	SnapshotCache  int
 
 	// Mining options
 	Miner miner.Config