core: extend code read statistics with cache and unique metrics

This extends the execution statistics infrastructure from #33442 with:

- Code cache hit/miss tracking (completing parity with account/storage)
- Code bytes read metric for I/O volume analysis
- Unique state access metrics (accounts, storage slots, contracts)

The slow block log now shows:

    Code read: 626ns(4, 1.07 KiB)

    Unique state access:
        Accounts: 6
        Storage slots: 11
        Contracts executed: 4

    Reader statistics
    account: hit: 4, miss: 6, rate: 40.00
    storage: hit: 0, miss: 11, rate: 0.00
    code: hit: 4, miss: 0, rate: 100.00

core/blockchain.go

@@ -87,6 +87,9 @@ var (
 	storageCacheHitPrefetchMeter  = metrics.NewRegisteredMeter("chain/storage/reads/cache/prefetch/hit", nil)
 	storageCacheMissPrefetchMeter = metrics.NewRegisteredMeter("chain/storage/reads/cache/prefetch/miss", nil)
 
+	codeCacheHitMeter  = metrics.NewRegisteredMeter("chain/code/reads/cache/hit", nil)
+	codeCacheMissMeter = metrics.NewRegisteredMeter("chain/code/reads/cache/miss", nil)
+
 	accountReadSingleTimer = metrics.NewRegisteredResettingTimer("chain/account/single/reads", nil)
 	storageReadSingleTimer = metrics.NewRegisteredResettingTimer("chain/storage/single/reads", nil)
 	codeReadSingleTimer    = metrics.NewRegisteredResettingTimer("chain/code/single/reads", nil)
@@ -2060,6 +2063,8 @@ func (bc *BlockChain) ProcessBlock(parentRoot common.Hash, block *types.Block, s
 			accountCacheMissMeter.Mark(rStat.AccountCacheMiss)
 			storageCacheHitMeter.Mark(rStat.StorageCacheHit)
 			storageCacheMissMeter.Mark(rStat.StorageCacheMiss)
+			codeCacheHitMeter.Mark(rStat.CodeCacheHit)
+			codeCacheMissMeter.Mark(rStat.CodeCacheMiss)
 
 			if result != nil {
 				result.stats.StatePrefetchCacheStats = pStat
@@ -2182,6 +2187,11 @@ func (bc *BlockChain) ProcessBlock(parentRoot common.Hash, block *types.Block, s
 	stats.StorageUpdated = int(statedb.StorageUpdated.Load())
 	stats.StorageDeleted = int(statedb.StorageDeleted.Load())
 	stats.CodeLoaded = statedb.CodeLoaded
+	stats.CodeBytesRead = statedb.CodeBytesRead
+
+	stats.UniqueAccountsAccessed = statedb.UniqueAccountsAccessed()
+	stats.UniqueStorageAccessed = statedb.UniqueStorageAccessed()
+	stats.UniqueCodeExecuted = statedb.UniqueCodeExecuted()
 
 	stats.Execution = ptime - (statedb.AccountReads + statedb.StorageReads + statedb.CodeReads)          // The time spent on EVM processing
 	stats.Validation = vtime - (statedb.AccountHashes + statedb.AccountUpdates + statedb.StorageUpdates) // The time spent on block validation

core/blockchain_stats.go

@@ -39,13 +39,19 @@ type ExecuteStats struct {
 	StorageCommits time.Duration // Time spent on the storage trie commit
 	CodeReads      time.Duration // Time spent on the contract code read
 
-	AccountLoaded  int // Number of accounts loaded
+	AccountLoaded  int   // Number of accounts loaded
-	AccountUpdated int // Number of accounts updated
+	AccountUpdated int   // Number of accounts updated
-	AccountDeleted int // Number of accounts deleted
+	AccountDeleted int   // Number of accounts deleted
-	StorageLoaded  int // Number of storage slots loaded
+	StorageLoaded  int   // Number of storage slots loaded
-	StorageUpdated int // Number of storage slots updated
+	StorageUpdated int   // Number of storage slots updated
-	StorageDeleted int // Number of storage slots deleted
+	StorageDeleted int   // Number of storage slots deleted
-	CodeLoaded     int // Number of contract code loaded
+	CodeLoaded     int   // Number of contract code loaded
+	CodeBytesRead  int64 // Total bytes of contract code read
+
+	// Unique access metrics
+	UniqueAccountsAccessed int // Number of unique accounts accessed
+	UniqueStorageAccessed  int // Number of unique storage slots accessed
+	UniqueCodeExecuted     int // Number of unique contracts executed
 
 	Execution       time.Duration // Time spent on the EVM execution
 	Validation      time.Duration // Time spent on the block validation
@@ -100,6 +106,8 @@ func (s *ExecuteStats) reportMetrics() {
 	accountCacheMissMeter.Mark(s.StateReadCacheStats.AccountCacheMiss)
 	storageCacheHitMeter.Mark(s.StateReadCacheStats.StorageCacheHit)
 	storageCacheMissMeter.Mark(s.StateReadCacheStats.StorageCacheMiss)
+	codeCacheHitMeter.Mark(s.StateReadCacheStats.CodeCacheHit)
+	codeCacheMissMeter.Mark(s.StateReadCacheStats.CodeCacheMiss)
 }
 
 // logSlow prints the detailed execution statistics if the block is regarded as slow.
@@ -119,7 +127,12 @@ Validation: %v
 State read: %v
     Account read: %v(%d)
     Storage read: %v(%d)
-    Code read: %v(%d)
+    Code read: %v(%d, %s)
+
+Unique state access:
+    Accounts: %d
+    Storage slots: %d
+    Contracts executed: %d
 
 State hash: %v
     Account hash: %v
@@ -140,7 +153,12 @@ DB write: %v
 		common.PrettyDuration(s.AccountReads+s.StorageReads+s.CodeReads),
 		common.PrettyDuration(s.AccountReads), s.AccountLoaded,
 		common.PrettyDuration(s.StorageReads), s.StorageLoaded,
-		common.PrettyDuration(s.CodeReads), s.CodeLoaded,
+		common.PrettyDuration(s.CodeReads), s.CodeLoaded, common.StorageSize(s.CodeBytesRead),
+
+		// Unique state access
+		s.UniqueAccountsAccessed,
+		s.UniqueStorageAccessed,
+		s.UniqueCodeExecuted,
 
 		// State hash
 		common.PrettyDuration(s.AccountHashes+s.AccountUpdates+s.StorageUpdates+max(s.AccountCommits, s.StorageCommits)),

core/state/database.go

@@ -226,7 +226,6 @@ func (db *CachingDB) Reader(stateRoot common.Hash) (Reader, error) {
 
 // ReadersWithCacheStats creates a pair of state readers sharing the same internal cache and
 // same backing Reader, but exposing separate statistics.
-// and statistics.
 func (db *CachingDB) ReadersWithCacheStats(stateRoot common.Hash) (ReaderWithStats, ReaderWithStats, error) {
 	reader, err := db.Reader(stateRoot)
 	if err != nil {

core/state/reader.go

@@ -98,6 +98,8 @@ type ReaderStats struct {
 	AccountCacheMiss int64
 	StorageCacheHit  int64
 	StorageCacheMiss int64
+	CodeCacheHit     int64
+	CodeCacheMiss    int64
 }
 
 // String implements fmt.Stringer, returning string format statistics.
@@ -105,6 +107,7 @@ func (s ReaderStats) String() string {
 	var (
 		accountCacheHitRate float64
 		storageCacheHitRate float64
+		codeCacheHitRate    float64
 	)
 	if s.AccountCacheHit > 0 {
 		accountCacheHitRate = float64(s.AccountCacheHit) / float64(s.AccountCacheHit+s.AccountCacheMiss) * 100
@@ -112,9 +115,13 @@ func (s ReaderStats) String() string {
 	if s.StorageCacheHit > 0 {
 		storageCacheHitRate = float64(s.StorageCacheHit) / float64(s.StorageCacheHit+s.StorageCacheMiss) * 100
 	}
+	if s.CodeCacheHit > 0 {
+		codeCacheHitRate = float64(s.CodeCacheHit) / float64(s.CodeCacheHit+s.CodeCacheMiss) * 100
+	}
 	msg := fmt.Sprintf("Reader statistics\n")
 	msg += fmt.Sprintf("account: hit: %d, miss: %d, rate: %.2f\n", s.AccountCacheHit, s.AccountCacheMiss, accountCacheHitRate)
 	msg += fmt.Sprintf("storage: hit: %d, miss: %d, rate: %.2f\n", s.StorageCacheHit, s.StorageCacheMiss, storageCacheHitRate)
+	msg += fmt.Sprintf("code: hit: %d, miss: %d, rate: %.2f\n", s.CodeCacheHit, s.CodeCacheMiss, codeCacheHitRate)
 	return msg
 }
 
@@ -146,32 +153,46 @@ func newCachingCodeReader(db ethdb.KeyValueReader, codeCache *lru.SizeConstraine
 	}
 }
 
-// Code implements ContractCodeReader, retrieving a particular contract's code.
+// code retrieves a particular contract's code along with a flag indicating
-// If the contract code doesn't exist, no error will be returned.
+// whether it was found in the cache.
-func (r *cachingCodeReader) Code(addr common.Address, codeHash common.Hash) ([]byte, error) {
+func (r *cachingCodeReader) code(addr common.Address, codeHash common.Hash) ([]byte, bool, error) {
-	code, _ := r.codeCache.Get(codeHash)
+	code, found := r.codeCache.Get(codeHash)
-	if len(code) > 0 {
+	if found && len(code) > 0 {
-		return code, nil
+		return code, true, nil
 	}
 	code = rawdb.ReadCode(r.db, codeHash)
 	if len(code) > 0 {
 		r.codeCache.Add(codeHash, code)
 		r.codeSizeCache.Add(codeHash, len(code))
 	}
-	return code, nil
+	return code, false, nil
+}
+
+// Code implements ContractCodeReader, retrieving a particular contract's code.
+// If the contract code doesn't exist, no error will be returned.
+func (r *cachingCodeReader) Code(addr common.Address, codeHash common.Hash) ([]byte, error) {
+	code, _, err := r.code(addr, codeHash)
+	return code, err
+}
+
+// codeSize retrieves a particular contract's code size along with a flag indicating
+// whether it was found in the cache.
+func (r *cachingCodeReader) codeSize(addr common.Address, codeHash common.Hash) (int, bool, error) {
+	if cached, ok := r.codeSizeCache.Get(codeHash); ok {
+		return cached, true, nil
+	}
+	code, _, err := r.code(addr, codeHash)
+	if err != nil {
+		return 0, false, err
+	}
+	return len(code), false, nil
 }
 
 // CodeSize implements ContractCodeReader, retrieving a particular contracts code's size.
 // If the contract code doesn't exist, no error will be returned.
 func (r *cachingCodeReader) CodeSize(addr common.Address, codeHash common.Hash) (int, error) {
-	if cached, ok := r.codeSizeCache.Get(codeHash); ok {
+	size, _, err := r.codeSize(addr, codeHash)
-		return cached, nil
+	return size, err
-	}
-	code, err := r.Code(addr, codeHash)
-	if err != nil {
-		return 0, err
-	}
-	return len(code), nil
 }
 
 // Has returns the flag indicating whether the contract code with
@@ -463,6 +484,28 @@ func newReader(codeReader ContractCodeReader, stateReader StateReader) *reader {
 	}
 }
 
+// code retrieves contract code with a flag indicating cache hit status.
+// Returns (code, incache, error). If the underlying code reader doesn't
+// support cache tracking, incache is always false.
+func (r *reader) code(addr common.Address, codeHash common.Hash) ([]byte, bool, error) {
+	if cr, ok := r.ContractCodeReader.(*cachingCodeReader); ok {
+		return cr.code(addr, codeHash)
+	}
+	code, err := r.ContractCodeReader.Code(addr, codeHash)
+	return code, false, err
+}
+
+// codeSize retrieves contract code size with a flag indicating cache hit status.
+// Returns (size, incache, error). If the underlying code reader doesn't
+// support cache tracking, incache is always false.
+func (r *reader) codeSize(addr common.Address, codeHash common.Hash) (int, bool, error) {
+	if cr, ok := r.ContractCodeReader.(*cachingCodeReader); ok {
+		return cr.codeSize(addr, codeHash)
+	}
+	size, err := r.ContractCodeReader.CodeSize(addr, codeHash)
+	return size, false, err
+}
+
 // readerWithCache is a wrapper around Reader that maintains additional state caches
 // to support concurrent state access.
 type readerWithCache struct {
@@ -573,6 +616,24 @@ func (r *readerWithCache) Storage(addr common.Address, slot common.Hash) (common
 	return value, err
 }
 
+// code retrieves contract code with a flag indicating cache hit status.
+func (r *readerWithCache) code(addr common.Address, codeHash common.Hash) ([]byte, bool, error) {
+	if rr, ok := r.Reader.(*reader); ok {
+		return rr.code(addr, codeHash)
+	}
+	code, err := r.Reader.Code(addr, codeHash)
+	return code, false, err
+}
+
+// codeSize retrieves contract code size with a flag indicating cache hit status.
+func (r *readerWithCache) codeSize(addr common.Address, codeHash common.Hash) (int, bool, error) {
+	if rr, ok := r.Reader.(*reader); ok {
+		return rr.codeSize(addr, codeHash)
+	}
+	size, err := r.Reader.CodeSize(addr, codeHash)
+	return size, false, err
+}
+
 type readerWithCacheStats struct {
 	*readerWithCache
 
@@ -580,6 +641,8 @@ type readerWithCacheStats struct {
 	accountCacheMiss atomic.Int64
 	storageCacheHit  atomic.Int64
 	storageCacheMiss atomic.Int64
+	codeCacheHit     atomic.Int64
+	codeCacheMiss    atomic.Int64
 }
 
 // newReaderWithCacheStats constructs the reader with additional statistics tracked.
@@ -624,6 +687,34 @@ func (r *readerWithCacheStats) Storage(addr common.Address, slot common.Hash) (c
 	return value, nil
 }
 
+// Code implements ContractCodeReader, retrieving a particular contract's code.
+func (r *readerWithCacheStats) Code(addr common.Address, codeHash common.Hash) ([]byte, error) {
+	code, incache, err := r.readerWithCache.code(addr, codeHash)
+	if err != nil {
+		return nil, err
+	}
+	if incache {
+		r.codeCacheHit.Add(1)
+	} else {
+		r.codeCacheMiss.Add(1)
+	}
+	return code, nil
+}
+
+// CodeSize implements ContractCodeReader, retrieving a particular contract's code size.
+func (r *readerWithCacheStats) CodeSize(addr common.Address, codeHash common.Hash) (int, error) {
+	size, incache, err := r.readerWithCache.codeSize(addr, codeHash)
+	if err != nil {
+		return 0, err
+	}
+	if incache {
+		r.codeCacheHit.Add(1)
+	} else {
+		r.codeCacheMiss.Add(1)
+	}
+	return size, nil
+}
+
 // GetStats implements ReaderWithStats, returning the statistics of state reader.
 func (r *readerWithCacheStats) GetStats() ReaderStats {
 	return ReaderStats{
@@ -631,5 +722,7 @@ func (r *readerWithCacheStats) GetStats() ReaderStats {
 		AccountCacheMiss: r.accountCacheMiss.Load(),
 		StorageCacheHit:  r.storageCacheHit.Load(),
 		StorageCacheMiss: r.storageCacheMiss.Load(),
+		CodeCacheHit:     r.codeCacheHit.Load(),
+		CodeCacheMiss:    r.codeCacheMiss.Load(),
 	}
 }

core/state/state_object.go

@@ -543,6 +543,7 @@ func (s *stateObject) Code() []byte {
 	if len(code) == 0 {
 		s.db.setError(fmt.Errorf("code is not found %x", s.CodeHash()))
 	}
+	s.db.CodeBytesRead += int64(len(code))
 	s.code = code
 	return code
 }

core/state/statedb.go

@@ -160,6 +160,10 @@ type StateDB struct {
 	StorageUpdated atomic.Int64 // Number of storage slots updated during the state transition
 	StorageDeleted atomic.Int64 // Number of storage slots deleted during the state transition
 	CodeLoaded     int          // Number of contract code loaded during the state transition
+	CodeBytesRead  int64        // Total bytes of contract code read during the state transition
+
+	// Unique contracts executed tracking (set of code hashes executed during the state transition)
+	executedCodes map[common.Hash]struct{}
 }
 
 // New creates a new state from a given trie.
@@ -186,6 +190,7 @@ func NewWithReader(root common.Hash, db Database, reader Reader) (*StateDB, erro
 		journal:              newJournal(),
 		accessList:           newAccessList(),
 		transientStorage:     newTransientStorage(),
+		executedCodes:        make(map[common.Hash]struct{}),
 	}
 	if db.TrieDB().IsVerkle() {
 		sdb.accessEvents = NewAccessEvents(db.PointCache())
@@ -379,6 +384,37 @@ func (s *StateDB) GetCodeHash(addr common.Address) common.Hash {
 	return common.Hash{}
 }
 
+// MarkCodeExecuted records that a contract's code was executed.
+// This is used for metrics tracking to count unique contracts executed.
+func (s *StateDB) MarkCodeExecuted(codeHash common.Hash) {
+	if codeHash == types.EmptyCodeHash || codeHash == (common.Hash{}) {
+		return
+	}
+	if s.executedCodes == nil {
+		return // Skip tracking for state copies (e.g., prefetcher)
+	}
+	s.executedCodes[codeHash] = struct{}{}
+}
+
+// UniqueCodeExecuted returns the number of unique contract codes executed.
+func (s *StateDB) UniqueCodeExecuted() int {
+	return len(s.executedCodes)
+}
+
+// UniqueAccountsAccessed returns the number of unique accounts accessed during the state transition.
+func (s *StateDB) UniqueAccountsAccessed() int {
+	return len(s.stateObjects)
+}
+
+// UniqueStorageAccessed returns the number of unique storage slots accessed during the state transition.
+func (s *StateDB) UniqueStorageAccessed() int {
+	count := 0
+	for _, obj := range s.stateObjects {
+		count += len(obj.originStorage)
+	}
+	return count
+}
+
 // GetState retrieves the value associated with the specific key.
 func (s *StateDB) GetState(addr common.Address, hash common.Hash) common.Hash {
 	stateObject := s.getStateObject(addr)

core/state/statedb_hooked.go

@@ -291,3 +291,13 @@ func (s *hookedStateDB) Finalise(deleteEmptyObjects bool) {
 		}
 	}
 }
+
+// Inner returns the underlying StateDB.
+func (s *hookedStateDB) Inner() *StateDB {
+	return s.inner
+}
+
+// MarkCodeExecuted records that a contract's code was executed.
+func (s *hookedStateDB) MarkCodeExecuted(codeHash common.Hash) {
+	s.inner.MarkCodeExecuted(codeHash)
+}

core/vm/evm.go

@@ -293,7 +293,10 @@ func (evm *EVM) Call(caller common.Address, addr common.Address, input []byte, g
 			// The contract is a scoped environment for this execution context only.
 			contract := NewContract(caller, addr, value, gas, evm.jumpDests)
 			contract.IsSystemCall = isSystemCall(caller)
-			contract.SetCallCode(evm.resolveCodeHash(addr), code)
+			codeHash := evm.resolveCodeHash(addr)
+			contract.SetCallCode(codeHash, code)
+			// Track unique contract execution for metrics
+			evm.StateDB.MarkCodeExecuted(codeHash)
 			ret, err = evm.Run(contract, input, false)
 			gas = contract.Gas
 		}
@@ -352,7 +355,10 @@ func (evm *EVM) CallCode(caller common.Address, addr common.Address, input []byt
 		// Initialise a new contract and set the code that is to be used by the EVM.
 		// The contract is a scoped environment for this execution context only.
 		contract := NewContract(caller, caller, value, gas, evm.jumpDests)
-		contract.SetCallCode(evm.resolveCodeHash(addr), evm.resolveCode(addr))
+		codeHash := evm.resolveCodeHash(addr)
+		contract.SetCallCode(codeHash, evm.resolveCode(addr))
+		// Track unique contract execution for metrics
+		evm.StateDB.MarkCodeExecuted(codeHash)
 		ret, err = evm.Run(contract, input, false)
 		gas = contract.Gas
 	}
@@ -396,7 +402,10 @@ func (evm *EVM) DelegateCall(originCaller common.Address, caller common.Address,
 		//
 		// Note: The value refers to the original value from the parent call.
 		contract := NewContract(originCaller, caller, value, gas, evm.jumpDests)
-		contract.SetCallCode(evm.resolveCodeHash(addr), evm.resolveCode(addr))
+		codeHash := evm.resolveCodeHash(addr)
+		contract.SetCallCode(codeHash, evm.resolveCode(addr))
+		// Track unique contract execution for metrics
+		evm.StateDB.MarkCodeExecuted(codeHash)
 		ret, err = evm.Run(contract, input, false)
 		gas = contract.Gas
 	}
@@ -447,7 +456,10 @@ func (evm *EVM) StaticCall(caller common.Address, addr common.Address, input []b
 		// Initialise a new contract and set the code that is to be used by the EVM.
 		// The contract is a scoped environment for this execution context only.
 		contract := NewContract(caller, addr, new(uint256.Int), gas, evm.jumpDests)
-		contract.SetCallCode(evm.resolveCodeHash(addr), evm.resolveCode(addr))
+		codeHash := evm.resolveCodeHash(addr)
+		contract.SetCallCode(codeHash, evm.resolveCode(addr))
+		// Track unique contract execution for metrics
+		evm.StateDB.MarkCodeExecuted(codeHash)
 
 		// When an error was returned by the EVM or when setting the creation code
 		// above we revert to the snapshot and consume any gas remaining. Additionally

core/vm/interface.go

@@ -101,4 +101,8 @@ type StateDB interface {
 
 	// Finalise must be invoked at the end of a transaction
 	Finalise(bool)
+
+	// MarkCodeExecuted records that a contract's code was executed.
+	// Used for metrics tracking to count unique contracts executed.
+	MarkCodeExecuted(codeHash common.Hash)
 }