eth/filters: add global block logs cache (#25459)

This adds a cache for block logs which is shared by all filters. The cache
size of is configurable using the `--cache.blocklogs` flag.

Co-authored-by: Felix Lange <fjl@twurst.com>

accounts/abi/bind/backends/simulated.go

@@ -68,7 +68,8 @@ type SimulatedBackend struct {
 	pendingState    *state.StateDB // Currently pending state that will be the active on request
 	pendingReceipts types.Receipts // Currently receipts for the pending block
 
-	events *filters.EventSystem // Event system for filtering log events live
+	events       *filters.EventSystem  // for filtering log events live
+	filterSystem *filters.FilterSystem // for filtering database logs
 
 	config *params.ChainConfig
 }
@@ -86,7 +87,11 @@ func NewSimulatedBackendWithDatabase(database ethdb.Database, alloc core.Genesis
 		blockchain: blockchain,
 		config:     genesis.Config,
 	}
-	backend.events = filters.NewEventSystem(&filterBackend{database, blockchain, backend}, false)
+
+	filterBackend := &filterBackend{database, blockchain, backend}
+	backend.filterSystem = filters.NewFilterSystem(filterBackend, filters.Config{})
+	backend.events = filters.NewEventSystem(backend.filterSystem, false)
+
 	backend.rollback(blockchain.CurrentBlock())
 	return backend
 }
@@ -689,7 +694,7 @@ func (b *SimulatedBackend) FilterLogs(ctx context.Context, query ethereum.Filter
 	var filter *filters.Filter
 	if query.BlockHash != nil {
 		// Block filter requested, construct a single-shot filter
-		filter = filters.NewBlockFilter(&filterBackend{b.database, b.blockchain, b}, *query.BlockHash, query.Addresses, query.Topics)
+		filter = b.filterSystem.NewBlockFilter(*query.BlockHash, query.Addresses, query.Topics)
 	} else {
 		// Initialize unset filter boundaries to run from genesis to chain head
 		from := int64(0)
@@ -701,7 +706,7 @@ func (b *SimulatedBackend) FilterLogs(ctx context.Context, query ethereum.Filter
 			to = query.ToBlock.Int64()
 		}
 		// Construct the range filter
-		filter = filters.NewRangeFilter(&filterBackend{b.database, b.blockchain, b}, from, to, query.Addresses, query.Topics)
+		filter = b.filterSystem.NewRangeFilter(from, to, query.Addresses, query.Topics)
 	}
 	// Run the filter and return all the logs
 	logs, err := filter.Logs(ctx)
@@ -828,6 +833,7 @@ type filterBackend struct {
 }
 
 func (fb *filterBackend) ChainDb() ethdb.Database { return fb.db }
+
 func (fb *filterBackend) EventMux() *event.TypeMux { panic("not supported") }
 
 func (fb *filterBackend) HeaderByNumber(ctx context.Context, block rpc.BlockNumber) (*types.Header, error) {
@@ -853,19 +859,8 @@ func (fb *filterBackend) GetReceipts(ctx context.Context, hash common.Hash) (typ
 	return rawdb.ReadReceipts(fb.db, hash, *number, fb.bc.Config()), nil
 }
 
-func (fb *filterBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error) {
+func (fb *filterBackend) GetLogs(ctx context.Context, hash common.Hash, number uint64) ([][]*types.Log, error) {
-	number := rawdb.ReadHeaderNumber(fb.db, hash)
+	logs := rawdb.ReadLogs(fb.db, hash, number, fb.bc.Config())
-	if number == nil {
-		return nil, nil
-	}
-	receipts := rawdb.ReadReceipts(fb.db, hash, *number, fb.bc.Config())
-	if receipts == nil {
-		return nil, nil
-	}
-	logs := make([][]*types.Log, len(receipts))
-	for i, receipt := range receipts {
-		logs[i] = receipt.Logs
-	}
 	return logs, nil
 }
 

cmd/geth/config.go

@@ -163,7 +163,9 @@ func makeFullNode(ctx *cli.Context) (*node.Node, ethapi.Backend) {
 		override := ctx.Bool(utils.OverrideTerminalTotalDifficultyPassed.Name)
 		cfg.Eth.OverrideTerminalTotalDifficultyPassed = &override
 	}
+
 	backend, eth := utils.RegisterEthService(stack, &cfg.Eth)
+
 	// Warn users to migrate if they have a legacy freezer format.
 	if eth != nil && !ctx.IsSet(utils.IgnoreLegacyReceiptsFlag.Name) {
 		firstIdx := uint64(0)
@@ -181,10 +183,15 @@ func makeFullNode(ctx *cli.Context) (*node.Node, ethapi.Backend) {
 			utils.Fatalf("Database has receipts with a legacy format. Please run `geth db freezer-migrate`.")
 		}
 	}
-	// Configure GraphQL if requested
+
+	// Configure log filter RPC API.
+	filterSystem := utils.RegisterFilterAPI(stack, backend, &cfg.Eth)
+
+	// Configure GraphQL if requested.
 	if ctx.IsSet(utils.GraphQLEnabledFlag.Name) {
-		utils.RegisterGraphQLService(stack, backend, cfg.Node)
+		utils.RegisterGraphQLService(stack, backend, filterSystem, &cfg.Node)
 	}
+
 	// Add the Ethereum Stats daemon if requested.
 	if cfg.Ethstats.URL != "" {
 		utils.RegisterEthStatsService(stack, backend, cfg.Ethstats.URL)

cmd/geth/main.go

@@ -117,6 +117,7 @@ var (
 		utils.CacheSnapshotFlag,
 		utils.CacheNoPrefetchFlag,
 		utils.CachePreimagesFlag,
+		utils.CacheLogSizeFlag,
 		utils.FDLimitFlag,
 		utils.ListenPortFlag,
 		utils.DiscoveryPortFlag,

cmd/utils/flags.go

@@ -43,6 +43,7 @@ import (
 	ethcatalyst "github.com/ethereum/go-ethereum/eth/catalyst"
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/ethconfig"
+	"github.com/ethereum/go-ethereum/eth/filters"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
 	"github.com/ethereum/go-ethereum/eth/tracers"
 	"github.com/ethereum/go-ethereum/ethdb"
@@ -64,6 +65,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/nat"
 	"github.com/ethereum/go-ethereum/p2p/netutil"
 	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/rpc"
 	pcsclite "github.com/gballet/go-libpcsclite"
 	gopsutil "github.com/shirou/gopsutil/mem"
 	"github.com/urfave/cli/v2"
@@ -491,6 +493,12 @@ var (
 		Usage:    "Enable recording the SHA3/keccak preimages of trie keys",
 		Category: flags.PerfCategory,
 	}
+	CacheLogSizeFlag = &cli.IntFlag{
+		Name:     "cache.blocklogs",
+		Usage:    "Size (in number of blocks) of the log cache for filtering",
+		Category: flags.PerfCategory,
+		Value:    ethconfig.Defaults.FilterLogCacheSize,
+	}
 	FDLimitFlag = &cli.IntFlag{
 		Name:     "fdlimit",
 		Usage:    "Raise the open file descriptor resource limit (default = system fd limit)",
@@ -1808,6 +1816,9 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 	if ctx.IsSet(CacheFlag.Name) || ctx.IsSet(CacheSnapshotFlag.Name) {
 		cfg.SnapshotCache = ctx.Int(CacheFlag.Name) * ctx.Int(CacheSnapshotFlag.Name) / 100
 	}
+	if ctx.IsSet(CacheLogSizeFlag.Name) {
+		cfg.FilterLogCacheSize = ctx.Int(CacheLogSizeFlag.Name)
+	}
 	if !ctx.Bool(SnapshotFlag.Name) {
 		// If snap-sync is requested, this flag is also required
 		if cfg.SyncMode == downloader.SnapSync {
@@ -2005,21 +2016,34 @@ func RegisterEthService(stack *node.Node, cfg *ethconfig.Config) (ethapi.Backend
 	return backend.APIBackend, backend
 }
 
-// RegisterEthStatsService configures the Ethereum Stats daemon and adds it to
+// RegisterEthStatsService configures the Ethereum Stats daemon and adds it to the node.
-// the given node.
 func RegisterEthStatsService(stack *node.Node, backend ethapi.Backend, url string) {
 	if err := ethstats.New(stack, backend, backend.Engine(), url); err != nil {
 		Fatalf("Failed to register the Ethereum Stats service: %v", err)
 	}
 }
 
-// RegisterGraphQLService is a utility function to construct a new service and register it against a node.
+// RegisterGraphQLService adds the GraphQL API to the node.
-func RegisterGraphQLService(stack *node.Node, backend ethapi.Backend, cfg node.Config) {
+func RegisterGraphQLService(stack *node.Node, backend ethapi.Backend, filterSystem *filters.FilterSystem, cfg *node.Config) {
-	if err := graphql.New(stack, backend, cfg.GraphQLCors, cfg.GraphQLVirtualHosts); err != nil {
+	err := graphql.New(stack, backend, filterSystem, cfg.GraphQLCors, cfg.GraphQLVirtualHosts)
+	if err != nil {
 		Fatalf("Failed to register the GraphQL service: %v", err)
 	}
 }
 
+// RegisterFilterAPI adds the eth log filtering RPC API to the node.
+func RegisterFilterAPI(stack *node.Node, backend ethapi.Backend, ethcfg *ethconfig.Config) *filters.FilterSystem {
+	isLightClient := ethcfg.SyncMode == downloader.LightSync
+	filterSystem := filters.NewFilterSystem(backend, filters.Config{
+		LogCacheSize: ethcfg.FilterLogCacheSize,
+	})
+	stack.RegisterAPIs([]rpc.API{{
+		Namespace: "eth",
+		Service:   filters.NewFilterAPI(filterSystem, isLightClient),
+	}})
+	return filterSystem
+}
+
 func SetupMetrics(ctx *cli.Context) {
 	if metrics.Enabled {
 		log.Info("Enabling metrics collection")

eth/api_backend.go

@@ -19,7 +19,6 @@ package eth
 import (
 	"context"
 	"errors"
-	"fmt"
 	"math/big"
 	"time"
 
@@ -202,17 +201,8 @@ func (b *EthAPIBackend) GetReceipts(ctx context.Context, hash common.Hash) (type
 	return b.eth.blockchain.GetReceiptsByHash(hash), nil
 }
 
-func (b *EthAPIBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error) {
+func (b *EthAPIBackend) GetLogs(ctx context.Context, hash common.Hash, number uint64) ([][]*types.Log, error) {
-	db := b.eth.ChainDb()
+	return rawdb.ReadLogs(b.eth.chainDb, hash, number, b.ChainConfig()), nil
-	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
 }
 
 func (b *EthAPIBackend) GetTd(ctx context.Context, hash common.Hash) *big.Int {

eth/backend.go

@@ -25,7 +25,6 @@ import (
 	"strings"
 	"sync"
 	"sync/atomic"
-	"time"
 
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
@@ -41,7 +40,6 @@ import (
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/eth/ethconfig"
-	"github.com/ethereum/go-ethereum/eth/filters"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
 	"github.com/ethereum/go-ethereum/eth/protocols/eth"
 	"github.com/ethereum/go-ethereum/eth/protocols/snap"
@@ -315,9 +313,6 @@ func (s *Ethereum) APIs() []rpc.API {
 		}, {
 			Namespace: "eth",
 			Service:   downloader.NewDownloaderAPI(s.handler.downloader, s.eventMux),
-		}, {
-			Namespace: "eth",
-			Service:   filters.NewFilterAPI(s.APIBackend, false, 5*time.Minute),
 		}, {
 			Namespace: "admin",
 			Service:   NewAdminAPI(s),

eth/ethconfig/config.go

@@ -83,6 +83,7 @@ var Defaults = Config{
 	TrieDirtyCache:          256,
 	TrieTimeout:             60 * time.Minute,
 	SnapshotCache:           102,
+	FilterLogCacheSize:      32,
 	Miner: miner.Config{
 		GasCeil:  30000000,
 		GasPrice: big.NewInt(params.GWei),
@@ -171,6 +172,9 @@ type Config struct {
 	SnapshotCache           int
 	Preimages               bool
 
+	// This is the number of blocks for which logs will be cached in the filter system.
+	FilterLogCacheSize int
+
 	// Mining options
 	Miner miner.Config
 

eth/ethconfig/gen_config.go

@@ -48,6 +48,7 @@ func (c Config) MarshalTOML() (interface{}, error) {
 		TrieTimeout                           time.Duration
 		SnapshotCache                         int
 		Preimages                             bool
+		FilterLogCacheSize                    int
 		Miner                                 miner.Config
 		Ethash                                ethash.Config
 		TxPool                                core.TxPoolConfig
@@ -93,6 +94,7 @@ func (c Config) MarshalTOML() (interface{}, error) {
 	enc.TrieTimeout = c.TrieTimeout
 	enc.SnapshotCache = c.SnapshotCache
 	enc.Preimages = c.Preimages
+	enc.FilterLogCacheSize = c.FilterLogCacheSize
 	enc.Miner = c.Miner
 	enc.Ethash = c.Ethash
 	enc.TxPool = c.TxPool
@@ -142,6 +144,7 @@ func (c *Config) UnmarshalTOML(unmarshal func(interface{}) error) error {
 		TrieTimeout                           *time.Duration
 		SnapshotCache                         *int
 		Preimages                             *bool
+		FilterLogCacheSize                    *int
 		Miner                                 *miner.Config
 		Ethash                                *ethash.Config
 		TxPool                                *core.TxPoolConfig
@@ -250,6 +253,9 @@ func (c *Config) UnmarshalTOML(unmarshal func(interface{}) error) error {
 	if dec.Preimages != nil {
 		c.Preimages = *dec.Preimages
 	}
+	if dec.FilterLogCacheSize != nil {
+		c.FilterLogCacheSize = *dec.FilterLogCacheSize
+	}
 	if dec.Miner != nil {
 		c.Miner = *dec.Miner
 	}

eth/filters/api.go

@@ -46,7 +46,7 @@ type filter struct {
 // FilterAPI offers support to create and manage filters. This will allow external clients to retrieve various
 // information related to the Ethereum protocol such als blocks, transactions and logs.
 type FilterAPI struct {
-	backend   Backend
+	sys       *FilterSystem
 	events    *EventSystem
 	filtersMu sync.Mutex
 	filters   map[rpc.ID]*filter
@@ -54,14 +54,14 @@ type FilterAPI struct {
 }
 
 // NewFilterAPI returns a new FilterAPI instance.
-func NewFilterAPI(backend Backend, lightMode bool, timeout time.Duration) *FilterAPI {
+func NewFilterAPI(system *FilterSystem, lightMode bool) *FilterAPI {
 	api := &FilterAPI{
-		backend: backend,
+		sys:     system,
-		events:  NewEventSystem(backend, lightMode),
+		events:  NewEventSystem(system, lightMode),
 		filters: make(map[rpc.ID]*filter),
-		timeout: timeout,
+		timeout: system.cfg.Timeout,
 	}
-	go api.timeoutLoop(timeout)
+	go api.timeoutLoop(system.cfg.Timeout)
 
 	return api
 }
@@ -320,7 +320,7 @@ func (api *FilterAPI) GetLogs(ctx context.Context, crit FilterCriteria) ([]*type
 	var filter *Filter
 	if crit.BlockHash != nil {
 		// Block filter requested, construct a single-shot filter
-		filter = NewBlockFilter(api.backend, *crit.BlockHash, crit.Addresses, crit.Topics)
+		filter = api.sys.NewBlockFilter(*crit.BlockHash, crit.Addresses, crit.Topics)
 	} else {
 		// Convert the RPC block numbers into internal representations
 		begin := rpc.LatestBlockNumber.Int64()
@@ -332,7 +332,7 @@ func (api *FilterAPI) GetLogs(ctx context.Context, crit FilterCriteria) ([]*type
 			end = crit.ToBlock.Int64()
 		}
 		// Construct the range filter
-		filter = NewRangeFilter(api.backend, begin, end, crit.Addresses, crit.Topics)
+		filter = api.sys.NewRangeFilter(begin, end, crit.Addresses, crit.Topics)
 	}
 	// Run the filter and return all the logs
 	logs, err := filter.Logs(ctx)
@@ -371,7 +371,7 @@ func (api *FilterAPI) GetFilterLogs(ctx context.Context, id rpc.ID) ([]*types.Lo
 	var filter *Filter
 	if f.crit.BlockHash != nil {
 		// Block filter requested, construct a single-shot filter
-		filter = NewBlockFilter(api.backend, *f.crit.BlockHash, f.crit.Addresses, f.crit.Topics)
+		filter = api.sys.NewBlockFilter(*f.crit.BlockHash, f.crit.Addresses, f.crit.Topics)
 	} else {
 		// Convert the RPC block numbers into internal representations
 		begin := rpc.LatestBlockNumber.Int64()
@@ -383,7 +383,7 @@ func (api *FilterAPI) GetFilterLogs(ctx context.Context, id rpc.ID) ([]*types.Lo
 			end = f.crit.ToBlock.Int64()
 		}
 		// Construct the range filter
-		filter = NewRangeFilter(api.backend, begin, end, f.crit.Addresses, f.crit.Topics)
+		filter = api.sys.NewRangeFilter(begin, end, f.crit.Addresses, f.crit.Topics)
 	}
 	// Run the filter and return all the logs
 	logs, err := filter.Logs(ctx)

eth/filters/bench_test.go

@@ -122,22 +122,27 @@ func benchmarkBloomBits(b *testing.B, sectionSize uint64) {
 
 	b.Log("Running filter benchmarks...")
 	start = time.Now()
-	var backend *testBackend
 
+	var (
+		backend *testBackend
+		sys     *FilterSystem
+	)
 	for i := 0; i < benchFilterCnt; i++ {
 		if i%20 == 0 {
 			db.Close()
 			db, _ = rawdb.NewLevelDBDatabase(benchDataDir, 128, 1024, "", false)
 			backend = &testBackend{db: db, sections: cnt}
+			sys = NewFilterSystem(backend, Config{})
 		}
 		var addr common.Address
 		addr[0] = byte(i)
 		addr[1] = byte(i / 256)
-		filter := NewRangeFilter(backend, 0, int64(cnt*sectionSize-1), []common.Address{addr}, nil)
+		filter := sys.NewRangeFilter(0, int64(cnt*sectionSize-1), []common.Address{addr}, nil)
 		if _, err := filter.Logs(context.Background()); err != nil {
-			b.Error("filter.Find error:", err)
+			b.Error("filter.Logs error:", err)
 		}
 	}
+
 	d = time.Since(start)
 	b.Log("Finished running filter benchmarks")
 	b.Log(" ", d, "total  ", d/time.Duration(benchFilterCnt), "per address", d*time.Duration(1000000)/time.Duration(benchFilterCnt*cnt*sectionSize), "per million blocks")
@@ -171,10 +176,11 @@ func BenchmarkNoBloomBits(b *testing.B) {
 
 	clearBloomBits(db)
 
+	_, sys := newTestFilterSystem(b, db, Config{})
+
 	b.Log("Running filter benchmarks...")
 	start := time.Now()
-	backend := &testBackend{db: db}
+	filter := sys.NewRangeFilter(0, int64(*headNum), []common.Address{{}}, nil)
-	filter := NewRangeFilter(backend, 0, int64(*headNum), []common.Address{{}}, nil)
 	filter.Logs(context.Background())
 	d := time.Since(start)
 	b.Log("Finished running filter benchmarks")

eth/filters/filter.go

@@ -22,37 +22,15 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/bloombits"
 	"github.com/ethereum/go-ethereum/core/types"
-	"github.com/ethereum/go-ethereum/ethdb"
-	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/rpc"
 )
 
-type Backend interface {
-	ChainDb() ethdb.Database
-	HeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Header, error)
-	HeaderByHash(ctx context.Context, blockHash common.Hash) (*types.Header, error)
-	GetReceipts(ctx context.Context, blockHash common.Hash) (types.Receipts, error)
-	GetLogs(ctx context.Context, blockHash common.Hash) ([][]*types.Log, error)
-	PendingBlockAndReceipts() (*types.Block, types.Receipts)
-
-	SubscribeNewTxsEvent(chan<- core.NewTxsEvent) event.Subscription
-	SubscribeChainEvent(ch chan<- core.ChainEvent) event.Subscription
-	SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription
-	SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription
-	SubscribePendingLogsEvent(ch chan<- []*types.Log) event.Subscription
-
-	BloomStatus() (uint64, uint64)
-	ServiceFilter(ctx context.Context, session *bloombits.MatcherSession)
-}
-
 // Filter can be used to retrieve and filter logs.
 type Filter struct {
-	backend Backend
+	sys *FilterSystem
 
-	db        ethdb.Database
 	addresses []common.Address
 	topics    [][]common.Hash
 
@@ -64,7 +42,7 @@ type Filter struct {
 
 // NewRangeFilter creates a new filter which uses a bloom filter on blocks to
 // figure out whether a particular block is interesting or not.
-func NewRangeFilter(backend Backend, begin, end int64, addresses []common.Address, topics [][]common.Hash) *Filter {
+func (sys *FilterSystem) NewRangeFilter(begin, end int64, addresses []common.Address, topics [][]common.Hash) *Filter {
 	// Flatten the address and topic filter clauses into a single bloombits filter
 	// system. Since the bloombits are not positional, nil topics are permitted,
 	// which get flattened into a nil byte slice.
@@ -83,10 +61,10 @@ func NewRangeFilter(backend Backend, begin, end int64, addresses []common.Addres
 		}
 		filters = append(filters, filter)
 	}
-	size, _ := backend.BloomStatus()
+	size, _ := sys.backend.BloomStatus()
 
 	// Create a generic filter and convert it into a range filter
-	filter := newFilter(backend, addresses, topics)
+	filter := newFilter(sys, addresses, topics)
 
 	filter.matcher = bloombits.NewMatcher(size, filters)
 	filter.begin = begin
@@ -97,21 +75,20 @@ func NewRangeFilter(backend Backend, begin, end int64, addresses []common.Addres
 
 // NewBlockFilter creates a new filter which directly inspects the contents of
 // a block to figure out whether it is interesting or not.
-func NewBlockFilter(backend Backend, block common.Hash, addresses []common.Address, topics [][]common.Hash) *Filter {
+func (sys *FilterSystem) NewBlockFilter(block common.Hash, addresses []common.Address, topics [][]common.Hash) *Filter {
 	// Create a generic filter and convert it into a block filter
-	filter := newFilter(backend, addresses, topics)
+	filter := newFilter(sys, addresses, topics)
 	filter.block = block
 	return filter
 }
 
 // newFilter creates a generic filter that can either filter based on a block hash,
 // or based on range queries. The search criteria needs to be explicitly set.
-func newFilter(backend Backend, addresses []common.Address, topics [][]common.Hash) *Filter {
+func newFilter(sys *FilterSystem, addresses []common.Address, topics [][]common.Hash) *Filter {
 	return &Filter{
-		backend:   backend,
+		sys:       sys,
 		addresses: addresses,
 		topics:    topics,
-		db:        backend.ChainDb(),
 	}
 }
 
@@ -120,14 +97,14 @@ func newFilter(backend Backend, addresses []common.Address, topics [][]common.Ha
 func (f *Filter) Logs(ctx context.Context) ([]*types.Log, error) {
 	// If we're doing singleton block filtering, execute and return
 	if f.block != (common.Hash{}) {
-		header, err := f.backend.HeaderByHash(ctx, f.block)
+		header, err := f.sys.backend.HeaderByHash(ctx, f.block)
 		if err != nil {
 			return nil, err
 		}
 		if header == nil {
 			return nil, errors.New("unknown block")
 		}
-		return f.blockLogs(ctx, header)
+		return f.blockLogs(ctx, header, false)
 	}
 	// Short-cut if all we care about is pending logs
 	if f.begin == rpc.PendingBlockNumber.Int64() {
@@ -137,7 +114,7 @@ func (f *Filter) Logs(ctx context.Context) ([]*types.Log, error) {
 		return f.pendingLogs()
 	}
 	// Figure out the limits of the filter range
-	header, _ := f.backend.HeaderByNumber(ctx, rpc.LatestBlockNumber)
+	header, _ := f.sys.backend.HeaderByNumber(ctx, rpc.LatestBlockNumber)
 	if header == nil {
 		return nil, nil
 	}
@@ -156,7 +133,7 @@ func (f *Filter) Logs(ctx context.Context) ([]*types.Log, error) {
 	var (
 		logs           []*types.Log
 		err            error
-		size, sections = f.backend.BloomStatus()
+		size, sections = f.sys.backend.BloomStatus()
 	)
 	if indexed := sections * size; indexed > uint64(f.begin) {
 		if indexed > end {
@@ -192,7 +169,7 @@ func (f *Filter) indexedLogs(ctx context.Context, end uint64) ([]*types.Log, err
 	}
 	defer session.Close()
 
-	f.backend.ServiceFilter(ctx, session)
+	f.sys.backend.ServiceFilter(ctx, session)
 
 	// Iterate over the matches until exhausted or context closed
 	var logs []*types.Log
@@ -211,11 +188,11 @@ func (f *Filter) indexedLogs(ctx context.Context, end uint64) ([]*types.Log, err
 			f.begin = int64(number) + 1
 
 			// Retrieve the suggested block and pull any truly matching logs
-			header, err := f.backend.HeaderByNumber(ctx, rpc.BlockNumber(number))
+			header, err := f.sys.backend.HeaderByNumber(ctx, rpc.BlockNumber(number))
 			if header == nil || err != nil {
 				return logs, err
 			}
-			found, err := f.checkMatches(ctx, header)
+			found, err := f.blockLogs(ctx, header, true)
 			if err != nil {
 				return logs, err
 			}
@@ -233,11 +210,11 @@ func (f *Filter) unindexedLogs(ctx context.Context, end uint64) ([]*types.Log, e
 	var logs []*types.Log
 
 	for ; f.begin <= int64(end); f.begin++ {
-		header, err := f.backend.HeaderByNumber(ctx, rpc.BlockNumber(f.begin))
+		header, err := f.sys.backend.HeaderByNumber(ctx, rpc.BlockNumber(f.begin))
 		if header == nil || err != nil {
 			return logs, err
 		}
-		found, err := f.blockLogs(ctx, header)
+		found, err := f.blockLogs(ctx, header, false)
 		if err != nil {
 			return logs, err
 		}
@@ -247,34 +224,34 @@ func (f *Filter) unindexedLogs(ctx context.Context, end uint64) ([]*types.Log, e
 }
 
 // blockLogs returns the logs matching the filter criteria within a single block.
-func (f *Filter) blockLogs(ctx context.Context, header *types.Header) (logs []*types.Log, err error) {
+func (f *Filter) blockLogs(ctx context.Context, header *types.Header, skipBloom bool) ([]*types.Log, error) {
-	if bloomFilter(header.Bloom, f.addresses, f.topics) {
+	// Fast track: no filtering criteria
-		found, err := f.checkMatches(ctx, header)
+	if len(f.addresses) == 0 && len(f.topics) == 0 {
+		list, err := f.sys.cachedGetLogs(ctx, header.Hash(), header.Number.Uint64())
 		if err != nil {
-			return logs, err
+			return nil, err
 		}
-		logs = append(logs, found...)
+		return flatten(list), nil
+	} else if skipBloom || bloomFilter(header.Bloom, f.addresses, f.topics) {
+		return f.checkMatches(ctx, header)
 	}
-	return logs, nil
+	return nil, nil
 }
 
 // checkMatches checks if the receipts belonging to the given header contain any log events that
 // match the filter criteria. This function is called when the bloom filter signals a potential match.
-func (f *Filter) checkMatches(ctx context.Context, header *types.Header) (logs []*types.Log, err error) {
+func (f *Filter) checkMatches(ctx context.Context, header *types.Header) ([]*types.Log, error) {
-	// Get the logs of the block
+	logsList, err := f.sys.cachedGetLogs(ctx, header.Hash(), header.Number.Uint64())
-	logsList, err := f.backend.GetLogs(ctx, header.Hash())
 	if err != nil {
 		return nil, err
 	}
-	var unfiltered []*types.Log
+
-	for _, logs := range logsList {
+	unfiltered := flatten(logsList)
-		unfiltered = append(unfiltered, logs...)
+	logs := filterLogs(unfiltered, nil, nil, f.addresses, f.topics)
-	}
-	logs = filterLogs(unfiltered, nil, nil, f.addresses, f.topics)
 	if len(logs) > 0 {
 		// We have matching logs, check if we need to resolve full logs via the light client
 		if logs[0].TxHash == (common.Hash{}) {
-			receipts, err := f.backend.GetReceipts(ctx, header.Hash())
+			receipts, err := f.sys.backend.GetReceipts(ctx, header.Hash())
 			if err != nil {
 				return nil, err
 			}
@@ -291,7 +268,7 @@ func (f *Filter) checkMatches(ctx context.Context, header *types.Header) (logs [
 
 // pendingLogs returns the logs matching the filter criteria within the pending block.
 func (f *Filter) pendingLogs() ([]*types.Log, error) {
-	block, receipts := f.backend.PendingBlockAndReceipts()
+	block, receipts := f.sys.backend.PendingBlockAndReceipts()
 	if bloomFilter(block.Bloom(), f.addresses, f.topics) {
 		var unfiltered []*types.Log
 		for _, r := range receipts {
@@ -376,3 +353,11 @@ func bloomFilter(bloom types.Bloom, addresses []common.Address, topics [][]commo
 	}
 	return true
 }
+
+func flatten(list [][]*types.Log) []*types.Log {
+	var flat []*types.Log
+	for _, logs := range list {
+		flat = append(flat, logs...)
+	}
+	return flat
+}

eth/filters/filter_system.go

@@ -27,13 +27,90 @@ import (
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/common"
 	"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/types"
+	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/rpc"
+	lru "github.com/hashicorp/golang-lru"
 )
 
+// Config represents the configuration of the filter system.
+type Config struct {
+	LogCacheSize int           // maximum number of cached blocks (default: 32)
+	Timeout      time.Duration // how long filters stay active (default: 5min)
+}
+
+func (cfg Config) withDefaults() Config {
+	if cfg.Timeout == 0 {
+		cfg.Timeout = 5 * time.Minute
+	}
+	if cfg.LogCacheSize == 0 {
+		cfg.LogCacheSize = 32
+	}
+	return cfg
+}
+
+type Backend interface {
+	ChainDb() ethdb.Database
+	HeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Header, error)
+	HeaderByHash(ctx context.Context, blockHash common.Hash) (*types.Header, error)
+	GetReceipts(ctx context.Context, blockHash common.Hash) (types.Receipts, error)
+	GetLogs(ctx context.Context, blockHash common.Hash, number uint64) ([][]*types.Log, error)
+	PendingBlockAndReceipts() (*types.Block, types.Receipts)
+
+	SubscribeNewTxsEvent(chan<- core.NewTxsEvent) event.Subscription
+	SubscribeChainEvent(ch chan<- core.ChainEvent) event.Subscription
+	SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription
+	SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription
+	SubscribePendingLogsEvent(ch chan<- []*types.Log) event.Subscription
+
+	BloomStatus() (uint64, uint64)
+	ServiceFilter(ctx context.Context, session *bloombits.MatcherSession)
+}
+
+// FilterSystem holds resources shared by all filters.
+type FilterSystem struct {
+	backend   Backend
+	logsCache *lru.Cache
+	cfg       *Config
+}
+
+// NewFilterSystem creates a filter system.
+func NewFilterSystem(backend Backend, config Config) *FilterSystem {
+	config = config.withDefaults()
+
+	cache, err := lru.New(config.LogCacheSize)
+	if err != nil {
+		panic(err)
+	}
+	return &FilterSystem{
+		backend:   backend,
+		logsCache: cache,
+		cfg:       &config,
+	}
+}
+
+// cachedGetLogs loads block logs from the backend and caches the result.
+func (sys *FilterSystem) cachedGetLogs(ctx context.Context, blockHash common.Hash, number uint64) ([][]*types.Log, error) {
+	cached, ok := sys.logsCache.Get(blockHash)
+	if ok {
+		return cached.([][]*types.Log), nil
+	}
+
+	logs, err := sys.backend.GetLogs(ctx, blockHash, number)
+	if err != nil {
+		return nil, err
+	}
+	if logs == nil {
+		return nil, fmt.Errorf("failed to get logs for block #%d (0x%s)", number, blockHash.TerminalString())
+	}
+	sys.logsCache.Add(blockHash, logs)
+	return logs, nil
+}
+
 // Type determines the kind of filter and is used to put the filter in to
 // the correct bucket when added.
 type Type byte
@@ -84,6 +161,7 @@ type subscription struct {
 // subscription which match the subscription criteria.
 type EventSystem struct {
 	backend   Backend
+	sys       *FilterSystem
 	lightMode bool
 	lastHead  *types.Header
 
@@ -110,9 +188,10 @@ type EventSystem struct {
 //
 // The returned manager has a loop that needs to be stopped with the Stop function
 // or by stopping the given mux.
-func NewEventSystem(backend Backend, lightMode bool) *EventSystem {
+func NewEventSystem(sys *FilterSystem, lightMode bool) *EventSystem {
 	m := &EventSystem{
-		backend:       backend,
+		sys:           sys,
+		backend:       sys.backend,
 		lightMode:     lightMode,
 		install:       make(chan *subscription),
 		uninstall:     make(chan *subscription),
@@ -405,7 +484,7 @@ func (es *EventSystem) lightFilterLogs(header *types.Header, addresses []common.
 		// Get the logs of the block
 		ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
 		defer cancel()
-		logsList, err := es.backend.GetLogs(ctx, header.Hash())
+		logsList, err := es.sys.cachedGetLogs(ctx, header.Hash(), header.Number.Uint64())
 		if err != nil {
 			return nil
 		}

eth/filters/filter_system_test.go

@@ -39,10 +39,6 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 )
 
-var (
-	deadline = 5 * time.Minute
-)
-
 type testBackend struct {
 	db              ethdb.Database
 	sections        uint64
@@ -91,17 +87,8 @@ func (b *testBackend) GetReceipts(ctx context.Context, hash common.Hash) (types.
 	return nil, nil
 }
 
-func (b *testBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error) {
+func (b *testBackend) GetLogs(ctx context.Context, hash common.Hash, number uint64) ([][]*types.Log, error) {
-	number := rawdb.ReadHeaderNumber(b.db, hash)
+	logs := rawdb.ReadLogs(b.db, hash, number, params.TestChainConfig)
-	if number == nil {
-		return nil, nil
-	}
-	receipts := rawdb.ReadReceipts(b.db, hash, *number, params.TestChainConfig)
-
-	logs := make([][]*types.Log, len(receipts))
-	for i, receipt := range receipts {
-		logs[i] = receipt.Logs
-	}
 	return logs, nil
 }
 
@@ -160,6 +147,12 @@ func (b *testBackend) ServiceFilter(ctx context.Context, session *bloombits.Matc
 	}()
 }
 
+func newTestFilterSystem(t testing.TB, db ethdb.Database, cfg Config) (*testBackend, *FilterSystem) {
+	backend := &testBackend{db: db}
+	sys := NewFilterSystem(backend, cfg)
+	return backend, sys
+}
+
 // TestBlockSubscription tests if a block subscription returns block hashes for posted chain events.
 // It creates multiple subscriptions:
 // - one at the start and should receive all posted chain events and a second (blockHashes)
@@ -170,8 +163,8 @@ func TestBlockSubscription(t *testing.T) {
 
 	var (
 		db           = rawdb.NewMemoryDatabase()
-		backend     = &testBackend{db: db}
+		backend, sys = newTestFilterSystem(t, db, Config{})
-		api         = NewFilterAPI(backend, false, deadline)
+		api          = NewFilterAPI(sys, false)
 		genesis      = (&core.Genesis{BaseFee: big.NewInt(params.InitialBaseFee)}).MustCommit(db)
 		chain, _     = core.GenerateChain(params.TestChainConfig, genesis, ethash.NewFaker(), db, 10, func(i int, gen *core.BlockGen) {})
 		chainEvents  = []core.ChainEvent{}
@@ -222,8 +215,8 @@ func TestPendingTxFilter(t *testing.T) {
 
 	var (
 		db           = rawdb.NewMemoryDatabase()
-		backend = &testBackend{db: db}
+		backend, sys = newTestFilterSystem(t, db, Config{})
-		api     = NewFilterAPI(backend, false, deadline)
+		api          = NewFilterAPI(sys, false)
 
 		transactions = []*types.Transaction{
 			types.NewTransaction(0, common.HexToAddress("0xb794f5ea0ba39494ce83a213fffba74279579268"), new(big.Int), 0, new(big.Int), nil),
@@ -277,8 +270,8 @@ func TestPendingTxFilter(t *testing.T) {
 func TestLogFilterCreation(t *testing.T) {
 	var (
 		db     = rawdb.NewMemoryDatabase()
-		backend = &testBackend{db: db}
+		_, sys = newTestFilterSystem(t, db, Config{})
-		api     = NewFilterAPI(backend, false, deadline)
+		api    = NewFilterAPI(sys, false)
 
 		testCases = []struct {
 			crit    FilterCriteria
@@ -324,8 +317,8 @@ func TestInvalidLogFilterCreation(t *testing.T) {
 
 	var (
 		db     = rawdb.NewMemoryDatabase()
-		backend = &testBackend{db: db}
+		_, sys = newTestFilterSystem(t, db, Config{})
-		api     = NewFilterAPI(backend, false, deadline)
+		api    = NewFilterAPI(sys, false)
 	)
 
 	// different situations where log filter creation should fail.
@@ -346,8 +339,8 @@ func TestInvalidLogFilterCreation(t *testing.T) {
 func TestInvalidGetLogsRequest(t *testing.T) {
 	var (
 		db        = rawdb.NewMemoryDatabase()
-		backend   = &testBackend{db: db}
+		_, sys    = newTestFilterSystem(t, db, Config{})
-		api       = NewFilterAPI(backend, false, deadline)
+		api       = NewFilterAPI(sys, false)
 		blockHash = common.HexToHash("0x1111111111111111111111111111111111111111111111111111111111111111")
 	)
 
@@ -371,8 +364,8 @@ func TestLogFilter(t *testing.T) {
 
 	var (
 		db           = rawdb.NewMemoryDatabase()
-		backend = &testBackend{db: db}
+		backend, sys = newTestFilterSystem(t, db, Config{})
-		api     = NewFilterAPI(backend, false, deadline)
+		api          = NewFilterAPI(sys, false)
 
 		firstAddr      = common.HexToAddress("0x1111111111111111111111111111111111111111")
 		secondAddr     = common.HexToAddress("0x2222222222222222222222222222222222222222")
@@ -485,8 +478,8 @@ func TestPendingLogsSubscription(t *testing.T) {
 
 	var (
 		db           = rawdb.NewMemoryDatabase()
-		backend = &testBackend{db: db}
+		backend, sys = newTestFilterSystem(t, db, Config{})
-		api     = NewFilterAPI(backend, false, deadline)
+		api          = NewFilterAPI(sys, false)
 
 		firstAddr      = common.HexToAddress("0x1111111111111111111111111111111111111111")
 		secondAddr     = common.HexToAddress("0x2222222222222222222222222222222222222222")
@@ -669,8 +662,8 @@ func TestPendingTxFilterDeadlock(t *testing.T) {
 
 	var (
 		db           = rawdb.NewMemoryDatabase()
-		backend = &testBackend{db: db}
+		backend, sys = newTestFilterSystem(t, db, Config{Timeout: timeout})
-		api     = NewFilterAPI(backend, false, timeout)
+		api          = NewFilterAPI(sys, false)
 		done         = make(chan struct{})
 	)
 

eth/filters/filter_test.go

@@ -44,7 +44,7 @@ func BenchmarkFilters(b *testing.B) {
 
 	var (
 		db, _   = rawdb.NewLevelDBDatabase(dir, 0, 0, "", false)
-		backend = &testBackend{db: db}
+		_, sys  = newTestFilterSystem(b, db, Config{})
 		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr1   = crypto.PubkeyToAddress(key1.PublicKey)
 		addr2   = common.BytesToAddress([]byte("jeff"))
@@ -89,7 +89,7 @@ func BenchmarkFilters(b *testing.B) {
 	}
 	b.ResetTimer()
 
-	filter := NewRangeFilter(backend, 0, -1, []common.Address{addr1, addr2, addr3, addr4}, nil)
+	filter := sys.NewRangeFilter(0, -1, []common.Address{addr1, addr2, addr3, addr4}, nil)
 
 	for i := 0; i < b.N; i++ {
 		logs, _ := filter.Logs(context.Background())
@@ -104,7 +104,7 @@ func TestFilters(t *testing.T) {
 
 	var (
 		db, _   = rawdb.NewLevelDBDatabase(dir, 0, 0, "", false)
-		backend = &testBackend{db: db}
+		_, sys  = newTestFilterSystem(t, db, Config{})
 		key1, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 		addr    = crypto.PubkeyToAddress(key1.PublicKey)
 
@@ -175,14 +175,14 @@ func TestFilters(t *testing.T) {
 		rawdb.WriteReceipts(db, block.Hash(), block.NumberU64(), receipts[i])
 	}
 
-	filter := NewRangeFilter(backend, 0, -1, []common.Address{addr}, [][]common.Hash{{hash1, hash2, hash3, hash4}})
+	filter := sys.NewRangeFilter(0, -1, []common.Address{addr}, [][]common.Hash{{hash1, hash2, hash3, hash4}})
 
 	logs, _ := filter.Logs(context.Background())
 	if len(logs) != 4 {
 		t.Error("expected 4 log, got", len(logs))
 	}
 
-	filter = NewRangeFilter(backend, 900, 999, []common.Address{addr}, [][]common.Hash{{hash3}})
+	filter = sys.NewRangeFilter(900, 999, []common.Address{addr}, [][]common.Hash{{hash3}})
 	logs, _ = filter.Logs(context.Background())
 	if len(logs) != 1 {
 		t.Error("expected 1 log, got", len(logs))
@@ -191,7 +191,7 @@ func TestFilters(t *testing.T) {
 		t.Errorf("expected log[0].Topics[0] to be %x, got %x", hash3, logs[0].Topics[0])
 	}
 
-	filter = NewRangeFilter(backend, 990, -1, []common.Address{addr}, [][]common.Hash{{hash3}})
+	filter = sys.NewRangeFilter(990, -1, []common.Address{addr}, [][]common.Hash{{hash3}})
 	logs, _ = filter.Logs(context.Background())
 	if len(logs) != 1 {
 		t.Error("expected 1 log, got", len(logs))
@@ -200,7 +200,7 @@ func TestFilters(t *testing.T) {
 		t.Errorf("expected log[0].Topics[0] to be %x, got %x", hash3, logs[0].Topics[0])
 	}
 
-	filter = NewRangeFilter(backend, 1, 10, nil, [][]common.Hash{{hash1, hash2}})
+	filter = sys.NewRangeFilter(1, 10, nil, [][]common.Hash{{hash1, hash2}})
 
 	logs, _ = filter.Logs(context.Background())
 	if len(logs) != 2 {
@@ -208,7 +208,7 @@ func TestFilters(t *testing.T) {
 	}
 
 	failHash := common.BytesToHash([]byte("fail"))
-	filter = NewRangeFilter(backend, 0, -1, nil, [][]common.Hash{{failHash}})
+	filter = sys.NewRangeFilter(0, -1, nil, [][]common.Hash{{failHash}})
 
 	logs, _ = filter.Logs(context.Background())
 	if len(logs) != 0 {
@@ -216,14 +216,14 @@ func TestFilters(t *testing.T) {
 	}
 
 	failAddr := common.BytesToAddress([]byte("failmenow"))
-	filter = NewRangeFilter(backend, 0, -1, []common.Address{failAddr}, nil)
+	filter = sys.NewRangeFilter(0, -1, []common.Address{failAddr}, nil)
 
 	logs, _ = filter.Logs(context.Background())
 	if len(logs) != 0 {
 		t.Error("expected 0 log, got", len(logs))
 	}
 
-	filter = NewRangeFilter(backend, 0, -1, nil, [][]common.Hash{{failHash}, {hash1}})
+	filter = sys.NewRangeFilter(0, -1, nil, [][]common.Hash{{failHash}, {hash1}})
 
 	logs, _ = filter.Logs(context.Background())
 	if len(logs) != 0 {

ethclient/gethclient/gethclient_test.go

@@ -31,6 +31,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth"
 	"github.com/ethereum/go-ethereum/eth/ethconfig"
+	"github.com/ethereum/go-ethereum/eth/filters"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/ethereum/go-ethereum/params"
@@ -60,6 +61,12 @@ func newTestBackend(t *testing.T) (*node.Node, []*types.Block) {
 	if err != nil {
 		t.Fatalf("can't create new ethereum service: %v", err)
 	}
+	filterSystem := filters.NewFilterSystem(ethservice.APIBackend, filters.Config{})
+	n.RegisterAPIs([]rpc.API{{
+		Namespace: "eth",
+		Service:   filters.NewFilterAPI(filterSystem, false),
+	}})
+
 	// Import the test chain.
 	if err := n.Start(); err != nil {
 		t.Fatalf("can't start test node: %v", err)

graphql/graphql.go

@@ -450,12 +450,36 @@ func (t *Transaction) CreatedContract(ctx context.Context, args BlockNumberArgs)
 }
 
 func (t *Transaction) Logs(ctx context.Context) (*[]*Log, error) {
-	receipt, err := t.getReceipt(ctx)
+	if _, err := t.resolve(ctx); err != nil {
-	if err != nil || receipt == nil {
 		return nil, err
 	}
-	ret := make([]*Log, 0, len(receipt.Logs))
+	if t.block == nil {
-	for _, log := range receipt.Logs {
+		return nil, nil
+	}
+	if _, ok := t.block.numberOrHash.Hash(); !ok {
+		header, err := t.r.backend.HeaderByNumberOrHash(ctx, *t.block.numberOrHash)
+		if err != nil {
+			return nil, err
+		}
+		hash := header.Hash()
+		t.block.numberOrHash.BlockHash = &hash
+	}
+	return t.getLogs(ctx)
+}
+
+// getLogs returns log objects for the given tx.
+// Assumes block hash is resolved.
+func (t *Transaction) getLogs(ctx context.Context) (*[]*Log, error) {
+	var (
+		hash, _   = t.block.numberOrHash.Hash()
+		filter    = t.r.filterSystem.NewBlockFilter(hash, nil, nil)
+		logs, err = filter.Logs(ctx)
+	)
+	if err != nil {
+		return nil, err
+	}
+	ret := make([]*Log, 0, len(logs))
+	for _, log := range logs {
 		ret = append(ret, &Log{
 			r:           t.r,
 			transaction: t,
@@ -978,7 +1002,7 @@ func (b *Block) Logs(ctx context.Context, args struct{ Filter BlockFilterCriteri
 		hash = header.Hash()
 	}
 	// Construct the range filter
-	filter := filters.NewBlockFilter(b.r.backend, hash, addresses, topics)
+	filter := b.r.filterSystem.NewBlockFilter(hash, addresses, topics)
 
 	// Run the filter and return all the logs
 	return runFilter(ctx, b.r, filter)
@@ -1138,6 +1162,7 @@ func (p *Pending) EstimateGas(ctx context.Context, args struct {
 // Resolver is the top-level object in the GraphQL hierarchy.
 type Resolver struct {
 	backend      ethapi.Backend
+	filterSystem *filters.FilterSystem
 }
 
 func (r *Resolver) Block(ctx context.Context, args struct {
@@ -1284,7 +1309,7 @@ func (r *Resolver) Logs(ctx context.Context, args struct{ Filter FilterCriteria
 		topics = *args.Filter.Topics
 	}
 	// Construct the range filter
-	filter := filters.NewRangeFilter(r.backend, begin, end, addresses, topics)
+	filter := r.filterSystem.NewRangeFilter(begin, end, addresses, topics)
 	return runFilter(ctx, r, filter)
 }
 

graphql/graphql_test.go

@@ -33,6 +33,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/eth"
 	"github.com/ethereum/go-ethereum/eth/ethconfig"
+	"github.com/ethereum/go-ethereum/eth/filters"
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/ethereum/go-ethereum/params"
 
@@ -50,7 +51,7 @@ func TestBuildSchema(t *testing.T) {
 	}
 	defer stack.Close()
 	// Make sure the schema can be parsed and matched up to the object model.
-	if err := newHandler(stack, nil, []string{}, []string{}); err != nil {
+	if err := newHandler(stack, nil, nil, []string{}, []string{}); err != nil {
 		t.Errorf("Could not construct GraphQL handler: %v", err)
 	}
 }
@@ -263,7 +264,8 @@ func createGQLService(t *testing.T, stack *node.Node) {
 		t.Fatalf("could not create import blocks: %v", err)
 	}
 	// create gql service
-	err = New(stack, ethBackend.APIBackend, []string{}, []string{})
+	filterSystem := filters.NewFilterSystem(ethBackend.APIBackend, filters.Config{})
+	err = New(stack, ethBackend.APIBackend, filterSystem, []string{}, []string{})
 	if err != nil {
 		t.Fatalf("could not create graphql service: %v", err)
 	}
@@ -348,7 +350,8 @@ func createGQLServiceWithTransactions(t *testing.T, stack *node.Node) {
 		t.Fatalf("could not create import blocks: %v", err)
 	}
 	// create gql service
-	err = New(stack, ethBackend.APIBackend, []string{}, []string{})
+	filterSystem := filters.NewFilterSystem(ethBackend.APIBackend, filters.Config{})
+	err = New(stack, ethBackend.APIBackend, filterSystem, []string{}, []string{})
 	if err != nil {
 		t.Fatalf("could not create graphql service: %v", err)
 	}

graphql/service.go

@@ -20,6 +20,7 @@ import (
 	"encoding/json"
 	"net/http"
 
+	"github.com/ethereum/go-ethereum/eth/filters"
 	"github.com/ethereum/go-ethereum/internal/ethapi"
 	"github.com/ethereum/go-ethereum/node"
 	"github.com/graph-gophers/graphql-go"
@@ -55,14 +56,14 @@ func (h handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 }
 
 // New constructs a new GraphQL service instance.
-func New(stack *node.Node, backend ethapi.Backend, cors, vhosts []string) error {
+func New(stack *node.Node, backend ethapi.Backend, filterSystem *filters.FilterSystem, cors, vhosts []string) error {
-	return newHandler(stack, backend, cors, vhosts)
+	return newHandler(stack, backend, filterSystem, cors, vhosts)
 }
 
 // newHandler returns a new `http.Handler` that will answer GraphQL queries.
 // It additionally exports an interactive query browser on the / endpoint.
-func newHandler(stack *node.Node, backend ethapi.Backend, cors, vhosts []string) error {
+func newHandler(stack *node.Node, backend ethapi.Backend, filterSystem *filters.FilterSystem, cors, vhosts []string) error {
-	q := Resolver{backend}
+	q := Resolver{backend, filterSystem}
 
 	s, err := graphql.ParseSchema(schema, &q)
 	if err != nil {

internal/ethapi/backend.go

@@ -27,10 +27,10 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus"
 	"github.com/ethereum/go-ethereum/core"
-	"github.com/ethereum/go-ethereum/core/bloombits"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
+	"github.com/ethereum/go-ethereum/eth/filters"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/params"
@@ -84,16 +84,12 @@ type Backend interface {
 	TxPoolContentFrom(addr common.Address) (types.Transactions, types.Transactions)
 	SubscribeNewTxsEvent(chan<- core.NewTxsEvent) event.Subscription
 
-	// Filter API
-	BloomStatus() (uint64, uint64)
-	GetLogs(ctx context.Context, blockHash common.Hash) ([][]*types.Log, error)
-	ServiceFilter(ctx context.Context, session *bloombits.MatcherSession)
-	SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription
-	SubscribePendingLogsEvent(ch chan<- []*types.Log) event.Subscription
-	SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription
-
 	ChainConfig() *params.ChainConfig
 	Engine() consensus.Engine
+
+	// eth/filters needs to be initialized from this backend type, so methods needed by
+	// it must also be included here.
+	filters.Backend
 }
 
 func GetAPIs(apiBackend Backend) []rpc.API {

les/api_backend.go

@@ -168,11 +168,8 @@ func (b *LesApiBackend) GetReceipts(ctx context.Context, hash common.Hash) (type
 	return nil, nil
 }
 
-func (b *LesApiBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types.Log, error) {
+func (b *LesApiBackend) GetLogs(ctx context.Context, hash common.Hash, number uint64) ([][]*types.Log, error) {
-	if number := rawdb.ReadHeaderNumber(b.eth.chainDb, hash); number != nil {
+	return light.GetBlockLogs(ctx, b.eth.odr, hash, number)
-		return light.GetBlockLogs(ctx, b.eth.odr, hash, *number)
-	}
-	return nil, nil
 }
 
 func (b *LesApiBackend) GetTd(ctx context.Context, hash common.Hash) *big.Int {

les/client.go

@@ -32,7 +32,6 @@ import (
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/eth/ethconfig"
-	"github.com/ethereum/go-ethereum/eth/filters"
 	"github.com/ethereum/go-ethereum/eth/gasprice"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/internal/ethapi"
@@ -298,9 +297,6 @@ func (s *LightEthereum) APIs() []rpc.API {
 		}, {
 			Namespace: "eth",
 			Service:   downloader.NewDownloaderAPI(s.handler.downloader, s.eventMux),
-		}, {
-			Namespace: "eth",
-			Service:   filters.NewFilterAPI(s.ApiBackend, true, 5*time.Minute),
 		}, {
 			Namespace: "net",
 			Service:   s.netRPCService,