cmd, eth: added light client and light server modes

eth/filters/filter.go

@@ -24,10 +24,23 @@ import (
 	"github.com/ethereum/go-ethereum/core"
 	"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"
+	"golang.org/x/net/context"
 )
 
+type Backend interface {
+	ChainDb() ethdb.Database
+	EventMux() *event.TypeMux
+	HeaderByNumber(ctx context.Context, blockNr rpc.BlockNumber) (*types.Header, error)
+	GetReceipts(ctx context.Context, blockHash common.Hash) (types.Receipts, error)
+}
+
 // Filter can be used to retrieve and filter logs
 type Filter struct {
+	backend   Backend
+	useMipMap bool
+
 	created time.Time
 
 	db         ethdb.Database
@@ -38,8 +51,12 @@ type Filter struct {
 
 // New creates a new filter which uses a bloom filter on blocks to figure out whether
 // a particular block is interesting or not.
-func New(db ethdb.Database) *Filter {
-	return &Filter{db: db}
+func New(backend Backend, useMipMap bool) *Filter {
+	return &Filter{
+		backend:   backend,
+		useMipMap: useMipMap,
+		db:        backend.ChainDb(),
+	}
 }
 
 // SetBeginBlock sets the earliest block for filtering.
@@ -66,30 +83,29 @@ func (f *Filter) SetTopics(topics [][]common.Hash) {
 }
 
 // Run filters logs with the current parameters set
-func (f *Filter) Find() []Log {
-	latestHash := core.GetHeadBlockHash(f.db)
-	latestBlock := core.GetBlock(f.db, latestHash, core.GetBlockNumber(f.db, latestHash))
-	if latestBlock == nil {
-		return []Log{}
+func (f *Filter) Find(ctx context.Context) ([]Log, error) {
+	head, _ := f.backend.HeaderByNumber(ctx, rpc.LatestBlockNumber)
+	if head == nil {
+		return nil, nil
 	}
+	headBlockNumber := head.Number.Uint64()
 
 	var beginBlockNo uint64 = uint64(f.begin)
 	if f.begin == -1 {
-		beginBlockNo = latestBlock.NumberU64()
+		beginBlockNo = headBlockNumber
 	}
-
-	endBlockNo := uint64(f.end)
+	var endBlockNo uint64 = uint64(f.end)
 	if f.end == -1 {
-		endBlockNo = latestBlock.NumberU64()
+		endBlockNo = headBlockNumber
 	}
 
 	// if no addresses are present we can't make use of fast search which
 	// uses the mipmap bloom filters to check for fast inclusion and uses
 	// higher range probability in order to ensure at least a false positive
-	if len(f.addresses) == 0 {
-		return f.getLogs(beginBlockNo, endBlockNo)
+	if !f.useMipMap || len(f.addresses) == 0 {
+		return f.getLogs(ctx, beginBlockNo, endBlockNo)
 	}
-	return f.mipFind(beginBlockNo, endBlockNo, 0)
+	return f.mipFind(beginBlockNo, endBlockNo, 0), nil
 }
 
 func (f *Filter) mipFind(start, end uint64, depth int) (logs []Log) {
@@ -107,7 +123,8 @@ func (f *Filter) mipFind(start, end uint64, depth int) (logs []Log) {
 				start := uint64(math.Max(float64(num), float64(start)))
 				end := uint64(math.Min(float64(num+level-1), float64(end)))
 				if depth+1 == len(core.MIPMapLevels) {
-					logs = append(logs, f.getLogs(start, end)...)
+					l, _ := f.getLogs(context.Background(), start, end)
+					logs = append(logs, l...)
 				} else {
 					logs = append(logs, f.mipFind(start, end, depth+1)...)
 				}
@@ -122,28 +139,22 @@ func (f *Filter) mipFind(start, end uint64, depth int) (logs []Log) {
 	return logs
 }
 
-func (f *Filter) getLogs(start, end uint64) (logs []Log) {
-	var block *types.Block
-
+func (f *Filter) getLogs(ctx context.Context, start, end uint64) (logs []Log, err error) {
 	for i := start; i <= end; i++ {
-		hash := core.GetCanonicalHash(f.db, i)
-		if hash != (common.Hash{}) {
-			block = core.GetBlock(f.db, hash, i)
-		} else { // block not found
-			return logs
-		}
-		if block == nil { // block not found/written
-			return logs
+		header, err := f.backend.HeaderByNumber(ctx, rpc.BlockNumber(i))
+		if header == nil || err != nil {
+			return logs, err
 		}
 
 		// Use bloom filtering to see if this block is interesting given the
 		// current parameters
-		if f.bloomFilter(block) {
+		if f.bloomFilter(header.Bloom) {
 			// Get the logs of the block
-			var (
-				receipts   = core.GetBlockReceipts(f.db, block.Hash(), i)
-				unfiltered []Log
-			)
+			receipts, err := f.backend.GetReceipts(ctx, header.Hash())
+			if err != nil {
+				return nil, err
+			}
+			var unfiltered []Log
 			for _, receipt := range receipts {
 				rl := make([]Log, len(receipt.Logs))
 				for i, l := range receipt.Logs {
@@ -155,7 +166,7 @@ func (f *Filter) getLogs(start, end uint64) (logs []Log) {
 		}
 	}
 
-	return logs
+	return logs, nil
 }
 
 func includes(addresses []common.Address, a common.Address) bool {
@@ -229,7 +240,7 @@ func bloomFilter(bloom types.Bloom, addresses []common.Address, topics [][]commo
 	for _, sub := range topics {
 		var included bool
 		for _, topic := range sub {
-			if (topic == common.Hash{}) || types.BloomLookup(block.Bloom(), topic) {
+			if (topic == common.Hash{}) || types.BloomLookup(bloom, topic) {
 				included = true
 				break
 			}