plugeth/les/odr.go

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// Copyright 2016 The go-ethereum Authors
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// 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/>.
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package les
import (
"context"
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"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/light"
"github.com/ethereum/go-ethereum/log"
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)
// LesOdr implements light.OdrBackend
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type LesOdr struct {
db ethdb.Database
stop chan struct{}
retriever *retrieveManager
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}
func NewLesOdr(db ethdb.Database, retriever *retrieveManager) *LesOdr {
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return &LesOdr{
db: db,
retriever: retriever,
stop: make(chan struct{}),
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}
}
func (odr *LesOdr) Stop() {
close(odr.stop)
}
func (odr *LesOdr) Database() ethdb.Database {
return odr.db
}
const (
MsgBlockBodies = iota
MsgCode
MsgReceipts
MsgProofs
MsgHeaderProofs
)
// 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 (self *LesOdr) Retrieve(ctx context.Context, req light.OdrRequest) (err error) {
lreq := LesRequest(req)
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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 = self.retriever.retrieve(ctx, reqID, rq, func(p distPeer, msg *Msg) error { return lreq.Validate(self.db, msg) }); err == nil {
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// retrieved from network, store in db
req.StoreResult(self.db)
} else {
log.Debug("Failed to retrieve data from network", "err", err)
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}
return
}