1 files changed, 129 insertions, 0 deletions
diff --git a/lds/odr.go b/lds/odr.go
new file mode 100644
index 000000000..40cbb9455
--- /dev/null
+++ b/lds/odr.go
@@ -0,0 +1,129 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package lds
+
+import (
+	"context"
+
+	"github.com/dexon-foundation/dexon/core"
+	"github.com/dexon-foundation/dexon/ethdb"
+	"github.com/dexon-foundation/dexon/light"
+	"github.com/dexon-foundation/dexon/log"
+)
+
+// LesOdr implements light.OdrBackend
+type LesOdr struct {
+	db                                         ethdb.Database
+	indexerConfig                              *light.IndexerConfig
+	chtIndexer, bloomTrieIndexer, bloomIndexer *core.ChainIndexer
+	retriever                                  *retrieveManager
+	stop                                       chan struct{}
+}
+
+func NewLesOdr(db ethdb.Database, config *light.IndexerConfig, retriever *retrieveManager) *LesOdr {
+	return &LesOdr{
+		db:            db,
+		indexerConfig: config,
+		retriever:     retriever,
+		stop:          make(chan struct{}),
+	}
+}
+
+// Stop cancels all pending retrievals
+func (odr *LesOdr) Stop() {
+	close(odr.stop)
+}
+
+// Database returns the backing database
+func (odr *LesOdr) Database() ethdb.Database {
+	return odr.db
+}
+
+// SetIndexers adds the necessary chain indexers to the ODR backend
+func (odr *LesOdr) SetIndexers(chtIndexer, bloomTrieIndexer, bloomIndexer *core.ChainIndexer) {
+	odr.chtIndexer = chtIndexer
+	odr.bloomTrieIndexer = bloomTrieIndexer
+	odr.bloomIndexer = bloomIndexer
+}
+
+// ChtIndexer returns the CHT chain indexer
+func (odr *LesOdr) ChtIndexer() *core.ChainIndexer {
+	return odr.chtIndexer
+}
+
+// BloomTrieIndexer returns the bloom trie chain indexer
+func (odr *LesOdr) BloomTrieIndexer() *core.ChainIndexer {
+	return odr.bloomTrieIndexer
+}
+
+// BloomIndexer returns the bloombits chain indexer
+func (odr *LesOdr) BloomIndexer() *core.ChainIndexer {
+	return odr.bloomIndexer
+}
+
+// IndexerConfig returns the indexer config.
+func (odr *LesOdr) IndexerConfig() *light.IndexerConfig {
+	return odr.indexerConfig
+}
+
+const (
+	MsgBlockBodies = iota
+	MsgCode
+	MsgReceipts
+	MsgProofsV1
+	MsgProofsV2
+	MsgHeaderProofs
+	MsgHelperTrieProofs
+)
+
+// Msg encodes a LES message that delivers reply data for a request
+type Msg struct {
+	MsgType int
+	ReqID   uint64
+	Obj     interface{}
+}
+
+// Retrieve tries to fetch an object from the LES network.
+// If the network retrieval was successful, it stores the object in local db.
+func (odr *LesOdr) Retrieve(ctx context.Context, req light.OdrRequest) (err error) {
+	lreq := LesRequest(req)
+
+	reqID := genReqID()
+	rq := &distReq{
+		getCost: func(dp distPeer) uint64 {
+			return lreq.GetCost(dp.(*peer))
+		},
+		canSend: func(dp distPeer) bool {
+			p := dp.(*peer)
+			return lreq.CanSend(p)
+		},
+		request: func(dp distPeer) func() {
+			p := dp.(*peer)
+			cost := lreq.GetCost(p)
+			p.fcServer.QueueRequest(reqID, cost)
+			return func() { lreq.Request(reqID, p) }
+		},
+	}
+
+	if err = odr.retriever.retrieve(ctx, reqID, rq, func(p distPeer, msg *Msg) error { return lreq.Validate(odr.db, msg) }, odr.stop); err == nil {
+		// retrieved from network, store in db
+		req.StoreResult(odr.db)
+	} else {
+		log.Debug("Failed to retrieve data from network", "err", err)
+	}
+	return
+}