cmd, core, eth: support disabling the concurrent state prefetcher

eth/backend.go

@@ -165,7 +165,13 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 			EWASMInterpreter:        config.EWASMInterpreter,
 			EVMInterpreter:          config.EVMInterpreter,
 		}
-		cacheConfig = &core.CacheConfig{Disabled: config.NoPruning, TrieCleanLimit: config.TrieCleanCache, TrieDirtyLimit: config.TrieDirtyCache, TrieTimeLimit: config.TrieTimeout}
+		cacheConfig = &core.CacheConfig{
+			TrieCleanLimit:      config.TrieCleanCache,
+			TrieCleanNoPrefetch: config.NoPrefetch,
+			TrieDirtyLimit:      config.TrieDirtyCache,
+			TrieDirtyDisabled:   config.NoPruning,
+			TrieTimeLimit:       config.TrieTimeout,
+		}
 	)
 	eth.blockchain, err = core.NewBlockChain(chainDb, cacheConfig, chainConfig, eth.engine, vmConfig, eth.shouldPreserve)
 	if err != nil {

eth/config.go

@@ -92,7 +92,9 @@ type Config struct {
 	// Protocol options
 	NetworkId uint64 // Network ID to use for selecting peers to connect to
 	SyncMode  downloader.SyncMode
-	NoPruning bool
+
+	NoPruning  bool // Whether to disable pruning and flush everything to disk
+	NoPrefetch bool // Whether to disable prefetching and only load state on demand
 
 	// Whitelist of required block number -> hash values to accept
 	Whitelist map[uint64]common.Hash `toml:"-"`