common/lru: add generic LRU implementation (#26162)

It seems there is no fully typed library implementation of an LRU cache.
So I wrote one. Method names are the same as github.com/hashicorp/golang-lru,
and the new type can be used as a drop-in replacement.

Two reasons to do this:

- It's much easier to understand what a cache is for when the types are right there.
- Performance: the new implementation is slightly faster and performs zero memory
   allocations in Add when the cache is at capacity. Overall, memory usage of the cache
   is much reduced because keys are values are no longer wrapped in interface.

core/blockchain.go

@@ -30,6 +30,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/lru"
 	"github.com/ethereum/go-ethereum/common/mclock"
 	"github.com/ethereum/go-ethereum/common/prque"
 	"github.com/ethereum/go-ethereum/consensus"
@@ -45,8 +46,8 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/trie"
-	lru "github.com/hashicorp/golang-lru"
 )
 
 var (
@@ -200,12 +201,14 @@ type BlockChain struct {
 	currentSafeBlock      atomic.Value // Current safe head
 
 	stateCache    state.Database // State database to reuse between imports (contains state cache)
-	bodyCache     *lru.Cache     // Cache for the most recent block bodies
-	bodyRLPCache  *lru.Cache     // Cache for the most recent block bodies in RLP encoded format
-	receiptsCache *lru.Cache     // Cache for the most recent receipts per block
-	blockCache    *lru.Cache     // Cache for the most recent entire blocks
-	txLookupCache *lru.Cache     // Cache for the most recent transaction lookup data.
-	futureBlocks  *lru.Cache     // future blocks are blocks added for later processing
+	bodyCache     *lru.Cache[common.Hash, *types.Body]
+	bodyRLPCache  *lru.Cache[common.Hash, rlp.RawValue]
+	receiptsCache *lru.Cache[common.Hash, []*types.Receipt]
+	blockCache    *lru.Cache[common.Hash, *types.Block]
+	txLookupCache *lru.Cache[common.Hash, *rawdb.LegacyTxLookupEntry]
+
+	// future blocks are blocks added for later processing
+	futureBlocks *lru.Cache[common.Hash, *types.Block]
 
 	wg            sync.WaitGroup //
 	quit          chan struct{}  // shutdown signal, closed in Stop.
@@ -227,12 +230,6 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, genesis *Genesis
 	if cacheConfig == nil {
 		cacheConfig = defaultCacheConfig
 	}
-	bodyCache, _ := lru.New(bodyCacheLimit)
-	bodyRLPCache, _ := lru.New(bodyCacheLimit)
-	receiptsCache, _ := lru.New(receiptsCacheLimit)
-	blockCache, _ := lru.New(blockCacheLimit)
-	txLookupCache, _ := lru.New(txLookupCacheLimit)
-	futureBlocks, _ := lru.New(maxFutureBlocks)
 
 	// Setup the genesis block, commit the provided genesis specification
 	// to database if the genesis block is not present yet, or load the
@@ -261,12 +258,12 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, genesis *Genesis
 		}),
 		quit:          make(chan struct{}),
 		chainmu:       syncx.NewClosableMutex(),
-		bodyCache:     bodyCache,
-		bodyRLPCache:  bodyRLPCache,
-		receiptsCache: receiptsCache,
-		blockCache:    blockCache,
-		txLookupCache: txLookupCache,
-		futureBlocks:  futureBlocks,
+		bodyCache:     lru.NewCache[common.Hash, *types.Body](bodyCacheLimit),
+		bodyRLPCache:  lru.NewCache[common.Hash, rlp.RawValue](bodyCacheLimit),
+		receiptsCache: lru.NewCache[common.Hash, []*types.Receipt](receiptsCacheLimit),
+		blockCache:    lru.NewCache[common.Hash, *types.Block](blockCacheLimit),
+		txLookupCache: lru.NewCache[common.Hash, *rawdb.LegacyTxLookupEntry](txLookupCacheLimit),
+		futureBlocks:  lru.NewCache[common.Hash, *types.Block](maxFutureBlocks),
 		engine:        engine,
 		vmConfig:      vmConfig,
 	}
@@ -957,7 +954,7 @@ func (bc *BlockChain) procFutureBlocks() {
 	blocks := make([]*types.Block, 0, bc.futureBlocks.Len())
 	for _, hash := range bc.futureBlocks.Keys() {
 		if block, exist := bc.futureBlocks.Peek(hash); exist {
-			blocks = append(blocks, block.(*types.Block))
+			blocks = append(blocks, block)
 		}
 	}
 	if len(blocks) > 0 {

core/blockchain_reader.go

@@ -96,8 +96,7 @@ func (bc *BlockChain) GetHeadersFrom(number, count uint64) []rlp.RawValue {
 func (bc *BlockChain) GetBody(hash common.Hash) *types.Body {
 	// Short circuit if the body's already in the cache, retrieve otherwise
 	if cached, ok := bc.bodyCache.Get(hash); ok {
-		body := cached.(*types.Body)
-		return body
+		return cached
 	}
 	number := bc.hc.GetBlockNumber(hash)
 	if number == nil {
@@ -117,7 +116,7 @@ func (bc *BlockChain) GetBody(hash common.Hash) *types.Body {
 func (bc *BlockChain) GetBodyRLP(hash common.Hash) rlp.RawValue {
 	// Short circuit if the body's already in the cache, retrieve otherwise
 	if cached, ok := bc.bodyRLPCache.Get(hash); ok {
-		return cached.(rlp.RawValue)
+		return cached
 	}
 	number := bc.hc.GetBlockNumber(hash)
 	if number == nil {
@@ -159,7 +158,7 @@ func (bc *BlockChain) HasFastBlock(hash common.Hash, number uint64) bool {
 func (bc *BlockChain) GetBlock(hash common.Hash, number uint64) *types.Block {
 	// Short circuit if the block's already in the cache, retrieve otherwise
 	if block, ok := bc.blockCache.Get(hash); ok {
-		return block.(*types.Block)
+		return block
 	}
 	block := rawdb.ReadBlock(bc.db, hash, number)
 	if block == nil {
@@ -211,7 +210,7 @@ func (bc *BlockChain) GetBlocksFromHash(hash common.Hash, n int) (blocks []*type
 // GetReceiptsByHash retrieves the receipts for all transactions in a given block.
 func (bc *BlockChain) GetReceiptsByHash(hash common.Hash) types.Receipts {
 	if receipts, ok := bc.receiptsCache.Get(hash); ok {
-		return receipts.(types.Receipts)
+		return receipts
 	}
 	number := rawdb.ReadHeaderNumber(bc.db, hash)
 	if number == nil {
@@ -255,7 +254,7 @@ func (bc *BlockChain) GetAncestor(hash common.Hash, number, ancestor uint64, max
 func (bc *BlockChain) GetTransactionLookup(hash common.Hash) *rawdb.LegacyTxLookupEntry {
 	// Short circuit if the txlookup already in the cache, retrieve otherwise
 	if lookup, exist := bc.txLookupCache.Get(hash); exist {
-		return lookup.(*rawdb.LegacyTxLookupEntry)
+		return lookup
 	}
 	tx, blockHash, blockNumber, txIndex := rawdb.ReadTransaction(bc.db, hash)
 	if tx == nil {

core/headerchain.go

@@ -27,6 +27,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/lru"
 	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
@@ -34,7 +35,6 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
-	lru "github.com/hashicorp/golang-lru"
 )
 
 const (
@@ -64,9 +64,9 @@ type HeaderChain struct {
 	currentHeader     atomic.Value // Current head of the header chain (may be above the block chain!)
 	currentHeaderHash common.Hash  // Hash of the current head of the header chain (prevent recomputing all the time)
 
-	headerCache *lru.Cache // Cache for the most recent block headers
-	tdCache     *lru.Cache // Cache for the most recent block total difficulties
-	numberCache *lru.Cache // Cache for the most recent block numbers
+	headerCache *lru.Cache[common.Hash, *types.Header]
+	tdCache     *lru.Cache[common.Hash, *big.Int] // most recent total difficulties
+	numberCache *lru.Cache[common.Hash, uint64]   // most recent block numbers
 
 	procInterrupt func() bool
 
@@ -77,10 +77,6 @@ type HeaderChain struct {
 // NewHeaderChain creates a new HeaderChain structure. ProcInterrupt points
 // to the parent's interrupt semaphore.
 func NewHeaderChain(chainDb ethdb.Database, config *params.ChainConfig, engine consensus.Engine, procInterrupt func() bool) (*HeaderChain, error) {
-	headerCache, _ := lru.New(headerCacheLimit)
-	tdCache, _ := lru.New(tdCacheLimit)
-	numberCache, _ := lru.New(numberCacheLimit)
-
 	// Seed a fast but crypto originating random generator
 	seed, err := crand.Int(crand.Reader, big.NewInt(math.MaxInt64))
 	if err != nil {
@@ -89,9 +85,9 @@ func NewHeaderChain(chainDb ethdb.Database, config *params.ChainConfig, engine c
 	hc := &HeaderChain{
 		config:        config,
 		chainDb:       chainDb,
-		headerCache:   headerCache,
-		tdCache:       tdCache,
-		numberCache:   numberCache,
+		headerCache:   lru.NewCache[common.Hash, *types.Header](headerCacheLimit),
+		tdCache:       lru.NewCache[common.Hash, *big.Int](tdCacheLimit),
+		numberCache:   lru.NewCache[common.Hash, uint64](numberCacheLimit),
 		procInterrupt: procInterrupt,
 		rand:          mrand.New(mrand.NewSource(seed.Int64())),
 		engine:        engine,
@@ -115,8 +111,7 @@ func NewHeaderChain(chainDb ethdb.Database, config *params.ChainConfig, engine c
 // from the cache or database
 func (hc *HeaderChain) GetBlockNumber(hash common.Hash) *uint64 {
 	if cached, ok := hc.numberCache.Get(hash); ok {
-		number := cached.(uint64)
-		return &number
+		return &cached
 	}
 	number := rawdb.ReadHeaderNumber(hc.chainDb, hash)
 	if number != nil {
@@ -442,7 +437,7 @@ func (hc *HeaderChain) GetAncestor(hash common.Hash, number, ancestor uint64, ma
 func (hc *HeaderChain) GetTd(hash common.Hash, number uint64) *big.Int {
 	// Short circuit if the td's already in the cache, retrieve otherwise
 	if cached, ok := hc.tdCache.Get(hash); ok {
-		return cached.(*big.Int)
+		return cached
 	}
 	td := rawdb.ReadTd(hc.chainDb, hash, number)
 	if td == nil {
@@ -458,7 +453,7 @@ func (hc *HeaderChain) GetTd(hash common.Hash, number uint64) *big.Int {
 func (hc *HeaderChain) GetHeader(hash common.Hash, number uint64) *types.Header {
 	// Short circuit if the header's already in the cache, retrieve otherwise
 	if header, ok := hc.headerCache.Get(hash); ok {
-		return header.(*types.Header)
+		return header
 	}
 	header := rawdb.ReadHeader(hc.chainDb, hash, number)
 	if header == nil {
@@ -525,10 +520,9 @@ func (hc *HeaderChain) GetHeadersFrom(number, count uint64) []rlp.RawValue {
 		if !ok {
 			break
 		}
-		h := header.(*types.Header)
-		rlpData, _ := rlp.EncodeToBytes(h)
+		rlpData, _ := rlp.EncodeToBytes(header)
 		headers = append(headers, rlpData)
-		hash = h.ParentHash
+		hash = header.ParentHash
 		count--
 		number--
 	}

core/state/database.go

@@ -21,12 +21,11 @@ import (
 	"fmt"
 
 	"github.com/ethereum/go-ethereum/common"
-	lru2 "github.com/ethereum/go-ethereum/common/lru"
+	"github.com/ethereum/go-ethereum/common/lru"
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/trie"
-	lru "github.com/hashicorp/golang-lru"
 )
 
 const (
@@ -130,20 +129,19 @@ func NewDatabase(db ethdb.Database) Database {
 // is safe for concurrent use and retains a lot of collapsed RLP trie nodes in a
 // large memory cache.
 func NewDatabaseWithConfig(db ethdb.Database, config *trie.Config) Database {
-	csc, _ := lru.New(codeSizeCacheSize)
 	return &cachingDB{
 		db:            trie.NewDatabaseWithConfig(db, config),
 		disk:          db,
-		codeSizeCache: csc,
-		codeCache:     lru2.NewSizeConstrainedLRU(codeCacheSize),
+		codeSizeCache: lru.NewCache[common.Hash, int](codeSizeCacheSize),
+		codeCache:     lru.NewSizeConstrainedCache[common.Hash, []byte](codeCacheSize),
 	}
 }
 
 type cachingDB struct {
 	db            *trie.Database
 	disk          ethdb.KeyValueStore
-	codeSizeCache *lru.Cache
-	codeCache     *lru2.SizeConstrainedLRU
+	codeSizeCache *lru.Cache[common.Hash, int]
+	codeCache     *lru.SizeConstrainedCache[common.Hash, []byte]
 }
 
 // OpenTrie opens the main account trie at a specific root hash.
@@ -176,10 +174,11 @@ func (db *cachingDB) CopyTrie(t Trie) Trie {
 
 // ContractCode retrieves a particular contract's code.
 func (db *cachingDB) ContractCode(addrHash, codeHash common.Hash) ([]byte, error) {
-	if code := db.codeCache.Get(codeHash); len(code) > 0 {
+	code, _ := db.codeCache.Get(codeHash)
+	if len(code) > 0 {
 		return code, nil
 	}
-	code := rawdb.ReadCode(db.disk, codeHash)
+	code = rawdb.ReadCode(db.disk, codeHash)
 	if len(code) > 0 {
 		db.codeCache.Add(codeHash, code)
 		db.codeSizeCache.Add(codeHash, len(code))
@@ -192,10 +191,11 @@ func (db *cachingDB) ContractCode(addrHash, codeHash common.Hash) ([]byte, error
 // code can't be found in the cache, then check the existence with **new**
 // db scheme.
 func (db *cachingDB) ContractCodeWithPrefix(addrHash, codeHash common.Hash) ([]byte, error) {
-	if code := db.codeCache.Get(codeHash); len(code) > 0 {
+	code, _ := db.codeCache.Get(codeHash)
+	if len(code) > 0 {
 		return code, nil
 	}
-	code := rawdb.ReadCodeWithPrefix(db.disk, codeHash)
+	code = rawdb.ReadCodeWithPrefix(db.disk, codeHash)
 	if len(code) > 0 {
 		db.codeCache.Add(codeHash, code)
 		db.codeSizeCache.Add(codeHash, len(code))
@@ -207,7 +207,7 @@ func (db *cachingDB) ContractCodeWithPrefix(addrHash, codeHash common.Hash) ([]b
 // ContractCodeSize retrieves a particular contracts code's size.
 func (db *cachingDB) ContractCodeSize(addrHash, codeHash common.Hash) (int, error) {
 	if cached, ok := db.codeSizeCache.Get(codeHash); ok {
-		return cached.(int), nil
+		return cached, nil
 	}
 	code, err := db.ContractCode(addrHash, codeHash)
 	return len(code), err