From 59f11516840bd86925bcd187837f54681c60f431 Mon Sep 17 00:00:00 2001
From: Sina Mahmoodi <itz.s1na@gmail.com>
Date: Mon, 1 Aug 2022 16:13:43 +0200
Subject: [PATCH] core,eth: cache logs in blockchain

---
 core/blockchain.go        |  5 +++++
 core/blockchain_reader.go | 17 +++++++++++++++++
 eth/api_backend.go        | 12 +-----------
 eth/filters/filter.go     |  4 ++++
 4 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/core/blockchain.go b/core/blockchain.go
index 506034b539a76..22f6a97b1c11d 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -88,6 +88,7 @@ const (
 	bodyCacheLimit      = 256
 	blockCacheLimit     = 256
 	receiptsCacheLimit  = 32
+	logsCacheLimit      = 32
 	txLookupCacheLimit  = 1024
 	maxFutureBlocks     = 256
 	maxTimeFutureBlocks = 30
@@ -198,6 +199,7 @@ type BlockChain struct {
 	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
+	logsCache     *lru.Cache     // Cache for the most recent logs 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
@@ -225,6 +227,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
 	bodyCache, _ := lru.New(bodyCacheLimit)
 	bodyRLPCache, _ := lru.New(bodyCacheLimit)
 	receiptsCache, _ := lru.New(receiptsCacheLimit)
+	logsCache, _ := lru.New(logsCacheLimit)
 	blockCache, _ := lru.New(blockCacheLimit)
 	txLookupCache, _ := lru.New(txLookupCacheLimit)
 	futureBlocks, _ := lru.New(maxFutureBlocks)
@@ -244,6 +247,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
 		bodyCache:     bodyCache,
 		bodyRLPCache:  bodyRLPCache,
 		receiptsCache: receiptsCache,
+		logsCache:     logsCache,
 		blockCache:    blockCache,
 		txLookupCache: txLookupCache,
 		futureBlocks:  futureBlocks,
@@ -681,6 +685,7 @@ func (bc *BlockChain) setHeadBeyondRoot(head uint64, root common.Hash, repair bo
 	bc.bodyCache.Purge()
 	bc.bodyRLPCache.Purge()
 	bc.receiptsCache.Purge()
+	bc.logsCache.Purge()
 	bc.blockCache.Purge()
 	bc.txLookupCache.Purge()
 	bc.futureBlocks.Purge()
diff --git a/core/blockchain_reader.go b/core/blockchain_reader.go
index 96e9f80b6aac3..dc3fd5b22df87 100644
--- a/core/blockchain_reader.go
+++ b/core/blockchain_reader.go
@@ -222,6 +222,23 @@ func (bc *BlockChain) GetReceiptsByHash(hash common.Hash) types.Receipts {
 	return receipts
 }
 
+// GetLogsByHash retrieves the logs for all transactions in a given block.
+func (bc *BlockChain) GetLogsByHash(hash common.Hash) [][]*types.Log {
+	if logs, ok := bc.logsCache.Get(hash); ok {
+		return logs.([][]*types.Log)
+	}
+	number := rawdb.ReadHeaderNumber(bc.db, hash)
+	if number == nil {
+		return nil
+	}
+	logs := rawdb.ReadLogs(bc.db, hash, *number, bc.chainConfig)
+	if logs == nil {
+		return nil
+	}
+	bc.logsCache.Add(hash, logs)
+	return logs
+}
+
 // GetUnclesInChain retrieves all the uncles from a given block backwards until
 // a specific distance is reached.
 func (bc *BlockChain) GetUnclesInChain(block *types.Block, length int) []*types.Header {
diff --git a/eth/api_backend.go b/eth/api_backend.go
index 1d8ba8ea5cae0..eb312e89d8c91 100644
--- a/eth/api_backend.go
+++ b/eth/api_backend.go
@@ -19,7 +19,6 @@ package eth
 import (
 	"context"
 	"errors"
-	"fmt"
 	"math/big"
 	"time"
 
@@ -203,16 +202,7 @@ func (b *EthAPIBackend) GetReceipts(ctx context.Context, hash common.Hash) (type
 }
 
 func (b *EthAPIBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error) {
-	db := b.eth.ChainDb()
-	number := rawdb.ReadHeaderNumber(db, hash)
-	if number == nil {
-		return nil, fmt.Errorf("failed to get block number for hash %#x", hash)
-	}
-	logs := rawdb.ReadLogs(db, hash, *number, b.eth.blockchain.Config())
-	if logs == nil {
-		return nil, fmt.Errorf("failed to get logs for block #%d (0x%s)", *number, hash.TerminalString())
-	}
-	return logs, nil
+	return b.eth.blockchain.GetLogsByHash(hash), nil
 }
 
 func (b *EthAPIBackend) GetTd(ctx context.Context, hash common.Hash) *big.Int {
diff --git a/eth/filters/filter.go b/eth/filters/filter.go
index 9ff7ab7f55e1e..b009b90b5b0f6 100644
--- a/eth/filters/filter.go
+++ b/eth/filters/filter.go
@@ -19,6 +19,7 @@ package filters
 import (
 	"context"
 	"errors"
+	"fmt"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -266,6 +267,9 @@ func (f *Filter) checkMatches(ctx context.Context, header *types.Header) (logs [
 	if err != nil {
 		return nil, err
 	}
+	if logsList == nil {
+		return nil, fmt.Errorf("failed to get logs for block #%d (0x%s)", header.Number.Uint64(), header.Hash().TerminalString())
+	}
 	var unfiltered []*types.Log
 	for _, logs := range logsList {
 		unfiltered = append(unfiltered, logs...)