From b69942befeb9f1af55cad0f91953bdaea2ea3efb Mon Sep 17 00:00:00 2001
From: Ryan Schneider <ryanleeschneider@gmail.com>
Date: Sat, 29 Sep 2018 13:53:31 -0700
Subject: [PATCH] core, internal/ethapi: add and use LRU cache for receipts
 (#17610)

---
 core/blockchain.go | 24 ++++++++++++++++++------
 eth/api_backend.go | 12 ++----------
 2 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/core/blockchain.go b/core/blockchain.go
index fe961e0c4..f4a818f4c 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -55,6 +55,7 @@ var (
 const (
 	bodyCacheLimit      = 256
 	blockCacheLimit     = 256
+	receiptsCacheLimit  = 32
 	maxFutureBlocks     = 256
 	maxTimeFutureBlocks = 30
 	badBlockLimit       = 10
@@ -111,11 +112,12 @@ type BlockChain struct {
 	currentBlock     atomic.Value // Current head of the block chain
 	currentFastBlock atomic.Value // Current head of the fast-sync chain (may be above the block chain!)
 
-	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
-	blockCache   *lru.Cache     // Cache for the most recent entire blocks
-	futureBlocks *lru.Cache     // future blocks are blocks added for later processing
+	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
+	futureBlocks  *lru.Cache     // future blocks are blocks added for later processing
 
 	quit    chan struct{} // blockchain quit channel
 	running int32         // running must be called atomically
@@ -144,6 +146,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
 	}
 	bodyCache, _ := lru.New(bodyCacheLimit)
 	bodyRLPCache, _ := lru.New(bodyCacheLimit)
+	receiptsCache, _ := lru.New(receiptsCacheLimit)
 	blockCache, _ := lru.New(blockCacheLimit)
 	futureBlocks, _ := lru.New(maxFutureBlocks)
 	badBlocks, _ := lru.New(badBlockLimit)
@@ -158,6 +161,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
 		shouldPreserve: shouldPreserve,
 		bodyCache:      bodyCache,
 		bodyRLPCache:   bodyRLPCache,
+		receiptsCache:  receiptsCache,
 		blockCache:     blockCache,
 		futureBlocks:   futureBlocks,
 		engine:         engine,
@@ -280,6 +284,7 @@ func (bc *BlockChain) SetHead(head uint64) error {
 	// Clear out any stale content from the caches
 	bc.bodyCache.Purge()
 	bc.bodyRLPCache.Purge()
+	bc.receiptsCache.Purge()
 	bc.blockCache.Purge()
 	bc.futureBlocks.Purge()
 
@@ -603,11 +608,18 @@ func (bc *BlockChain) GetBlockByNumber(number uint64) *types.Block {
 
 // 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)
+	}
+
 	number := rawdb.ReadHeaderNumber(bc.db, hash)
 	if number == nil {
 		return nil
 	}
-	return rawdb.ReadReceipts(bc.db, hash, *number)
+
+	receipts := rawdb.ReadReceipts(bc.db, hash, *number)
+	bc.receiptsCache.Add(hash, receipts)
+	return receipts
 }
 
 // GetBlocksFromHash returns the block corresponding to hash and up to n-1 ancestors.
diff --git a/eth/api_backend.go b/eth/api_backend.go
index 03f6012d7..8748d444f 100644
--- a/eth/api_backend.go
+++ b/eth/api_backend.go
@@ -25,7 +25,6 @@ import (
 	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/bloombits"
-	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
@@ -107,18 +106,11 @@ func (b *EthAPIBackend) GetBlock(ctx context.Context, hash common.Hash) (*types.
 }
 
 func (b *EthAPIBackend) GetReceipts(ctx context.Context, hash common.Hash) (types.Receipts, error) {
-	if number := rawdb.ReadHeaderNumber(b.eth.chainDb, hash); number != nil {
-		return rawdb.ReadReceipts(b.eth.chainDb, hash, *number), nil
-	}
-	return nil, nil
+	return b.eth.blockchain.GetReceiptsByHash(hash), nil
 }
 
 func (b *EthAPIBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error) {
-	number := rawdb.ReadHeaderNumber(b.eth.chainDb, hash)
-	if number == nil {
-		return nil, nil
-	}
-	receipts := rawdb.ReadReceipts(b.eth.chainDb, hash, *number)
+	receipts := b.eth.blockchain.GetReceiptsByHash(hash)
 	if receipts == nil {
 		return nil, nil
 	}