core: add reader statistics

core/blockchain.go

@@ -77,6 +77,11 @@ var (
 	storageUpdateTimer = metrics.NewRegisteredResettingTimer("chain/storage/updates", nil)
 	storageCommitTimer = metrics.NewRegisteredResettingTimer("chain/storage/commits", nil)
 
+	accountCacheHitMeter  = metrics.NewRegisteredMeter("chain/account/reads/cache/hit", nil)
+	accountCacheMissMeter = metrics.NewRegisteredMeter("chain/account/reads/cache/miss", nil)
+	storageCacheHitMeter  = metrics.NewRegisteredMeter("chain/storage/reads/cache/hit", nil)
+	storageCacheMissMeter = metrics.NewRegisteredMeter("chain/storage/reads/cache/miss", nil)
+
 	accountReadSingleTimer = metrics.NewRegisteredResettingTimer("chain/account/single/reads", nil)
 	storageReadSingleTimer = metrics.NewRegisteredResettingTimer("chain/storage/single/reads", nil)
 
@@ -1925,18 +1930,27 @@ func (bc *BlockChain) processBlock(parentRoot common.Hash, block *types.Block, s
 		//
 		// Note: the main processor and prefetcher share the same reader with a local
 		// cache for mitigating the overhead of state access.
-		reader, err := bc.statedb.ReaderWithCache(parentRoot)
+		prefetch, process, err := bc.statedb.ReaderWithCacheStats(parentRoot)
 		if err != nil {
 			return nil, err
 		}
-		throwaway, err := state.NewWithReader(parentRoot, bc.statedb, reader)
+		throwaway, err := state.NewWithReader(parentRoot, bc.statedb, prefetch)
 		if err != nil {
 			return nil, err
 		}
-		statedb, err = state.NewWithReader(parentRoot, bc.statedb, reader)
+		statedb, err = state.NewWithReader(parentRoot, bc.statedb, process)
 		if err != nil {
 			return nil, err
 		}
+		// Upload the statistics of reader at the end
+		defer func() {
+			stats := process.GetStats()
+			accountCacheHitMeter.Mark(stats.AccountHit)
+			accountCacheMissMeter.Mark(stats.AccountMiss)
+			storageCacheHitMeter.Mark(stats.StorageHit)
+			storageCacheMissMeter.Mark(stats.StorageMiss)
+		}()
+
 		go func(start time.Time, throwaway *state.StateDB, block *types.Block) {
 			// Disable tracing for prefetcher executions.
 			vmCfg := bc.vmConfig

core/state/database.go

@@ -209,13 +209,15 @@ func (db *CachingDB) Reader(stateRoot common.Hash) (Reader, error) {
 	return newReader(newCachingCodeReader(db.disk, db.codeCache, db.codeSizeCache), combined), nil
 }
 
-// ReaderWithCache creates a state reader with internal local cache.
-func (db *CachingDB) ReaderWithCache(stateRoot common.Hash) (Reader, error) {
+// ReaderWithCacheStats creates a pair of state readers with internal local cache
+// and statistics.
+func (db *CachingDB) ReaderWithCacheStats(stateRoot common.Hash) (ReaderWithStats, ReaderWithStats, error) {
 	reader, err := db.Reader(stateRoot)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
-	return newReaderWithCache(reader), nil
+	shared := newReaderWithCache(reader)
+	return newReaderWithCacheStats(shared), newReaderWithCacheStats(shared), nil
 }
 
 // OpenTrie opens the main account trie at a specific root hash.

core/state/reader.go

@@ -19,6 +19,7 @@ package state
 import (
 	"errors"
 	"sync"
+	"sync/atomic"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/lru"
@@ -82,6 +83,20 @@ type Reader interface {
 	StateReader
 }
 
+// ReaderStats wraps the statistics of reader.
+type ReaderStats struct {
+	AccountHit  int64
+	AccountMiss int64
+	StorageHit  int64
+	StorageMiss int64
+}
+
+// ReaderWithStats wraps the additional methods to retrieve the reader statistics from.
+type ReaderWithStats interface {
+	Reader
+	GetStats() ReaderStats
+}
+
 // cachingCodeReader implements ContractCodeReader, accessing contract code either in
 // local key-value store or the shared code cache.
 //
@@ -416,35 +431,43 @@ func newReaderWithCache(reader Reader) *readerWithCache {
 	return r
 }
 
-// Account implements StateReader, retrieving the account specified by the address.
-// The returned account might be nil if it's not existent.
+// account retrieves the account specified by the address along with a flag
+// indicating whether it's found in the cache or not. The returned account
+// might be nil if it's not existent.
 //
 // An error will be returned if the state is corrupted in the underlying reader.
-func (r *readerWithCache) Account(addr common.Address) (*types.StateAccount, error) {
+func (r *readerWithCache) account(addr common.Address) (*types.StateAccount, bool, error) {
 	// Try to resolve the requested account in the local cache
 	r.accountLock.RLock()
 	acct, ok := r.accounts[addr]
 	r.accountLock.RUnlock()
 	if ok {
-		return acct, nil
+		return acct, true, nil
 	}
 	// Try to resolve the requested account from the underlying reader
 	acct, err := r.Reader.Account(addr)
 	if err != nil {
-		return nil, err
+		return nil, false, err
 	}
 	r.accountLock.Lock()
 	r.accounts[addr] = acct
 	r.accountLock.Unlock()
-	return acct, nil
+	return acct, false, nil
 }
 
-// Storage implements StateReader, retrieving the storage slot specified by the
-// address and slot key. The returned storage slot might be empty if it's not
-// existent.
+// Account implements StateReader, retrieving the account specified by the address.
+// The returned account might be nil if it's not existent.
 //
 // An error will be returned if the state is corrupted in the underlying reader.
-func (r *readerWithCache) Storage(addr common.Address, slot common.Hash) (common.Hash, error) {
+func (r *readerWithCache) Account(addr common.Address) (*types.StateAccount, error) {
+	account, _, err := r.account(addr)
+	return account, err
+}
+
+// storage retrieves the storage slot specified by the address and slot key, along
+// with a flag indicating whether it's found in the cache or not. The returned
+// storage slot might be empty if it's not existent.
+func (r *readerWithCache) storage(addr common.Address, slot common.Hash) (common.Hash, bool, error) {
 	var (
 		value  common.Hash
 		ok     bool
@@ -458,12 +481,12 @@ func (r *readerWithCache) Storage(addr common.Address, slot common.Hash) (common
 	}
 	bucket.lock.RUnlock()
 	if ok {
-		return value, nil
+		return value, true, nil
 	}
 	// Try to resolve the requested storage slot from the underlying reader
 	value, err := r.Reader.Storage(addr, slot)
 	if err != nil {
-		return common.Hash{}, err
+		return common.Hash{}, false, err
 	}
 	bucket.lock.Lock()
 	slots, ok = bucket.storages[addr]
@@ -474,5 +497,75 @@ func (r *readerWithCache) Storage(addr common.Address, slot common.Hash) (common
 	slots[slot] = value
 	bucket.lock.Unlock()
 
+	return value, false, nil
+}
+
+// Storage implements StateReader, retrieving the storage slot specified by the
+// address and slot key. The returned storage slot might be empty if it's not
+// existent.
+//
+// An error will be returned if the state is corrupted in the underlying reader.
+func (r *readerWithCache) Storage(addr common.Address, slot common.Hash) (common.Hash, error) {
+	value, _, err := r.storage(addr, slot)
+	return value, err
+}
+
+type readerWithCacheStats struct {
+	*readerWithCache
+	accountHit  atomic.Int64
+	accountMiss atomic.Int64
+	storageHit  atomic.Int64
+	storageMiss atomic.Int64
+}
+
+// newReaderWithCacheStats constructs the reader with additional statistics tracked.
+func newReaderWithCacheStats(reader *readerWithCache) *readerWithCacheStats {
+	return &readerWithCacheStats{
+		readerWithCache: reader,
+	}
+}
+
+// Account implements StateReader, retrieving the account specified by the address.
+// The returned account might be nil if it's not existent.
+//
+// An error will be returned if the state is corrupted in the underlying reader.
+func (r *readerWithCacheStats) Account(addr common.Address) (*types.StateAccount, error) {
+	account, found, err := r.readerWithCache.account(addr)
+	if err != nil {
+		return nil, err
+	}
+	if found {
+		r.accountHit.Add(1)
+	} else {
+		r.accountMiss.Add(1)
+	}
+	return account, nil
+}
+
+// Storage implements StateReader, retrieving the storage slot specified by the
+// address and slot key. The returned storage slot might be empty if it's not
+// existent.
+//
+// An error will be returned if the state is corrupted in the underlying reader.
+func (r *readerWithCacheStats) Storage(addr common.Address, slot common.Hash) (common.Hash, error) {
+	value, found, err := r.readerWithCache.storage(addr, slot)
+	if err != nil {
+		return common.Hash{}, err
+	}
+	if found {
+		r.storageHit.Add(1)
+	} else {
+		r.storageMiss.Add(1)
+	}
 	return value, nil
 }
+
+// GetStats implements ReaderWithStats, returns the statistics of state reader.
+func (r *readerWithCacheStats) GetStats() ReaderStats {
+	return ReaderStats{
+		AccountHit:  r.accountHit.Load(),
+		AccountMiss: r.accountMiss.Load(),
+		StorageHit:  r.storageHit.Load(),
+		StorageMiss: r.storageMiss.Load(),
+	}
+}