// Copyright 2018 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 stream
import (
"context"
"strconv"
"time"
"github.com/ethereum/go-ethereum/metrics"
"github.com/ethereum/go-ethereum/swarm/log"
"github.com/ethereum/go-ethereum/swarm/storage"
)
const (
BatchSize = 128
)
// SwarmSyncerServer implements an Server for history syncing on bins
// offered streams:
// * live request delivery with or without checkback
// * (live/non-live historical) chunk syncing per proximity bin
type SwarmSyncerServer struct {
po uint8
store storage.SyncChunkStore
quit chan struct{}
}
// NewSwarmSyncerServer is constructor for SwarmSyncerServer
func NewSwarmSyncerServer(po uint8, syncChunkStore storage.SyncChunkStore) (*SwarmSyncerServer, error) {
return &SwarmSyncerServer{
po: po,
store: syncChunkStore,
quit: make(chan struct{}),
}, nil
}
func RegisterSwarmSyncerServer(streamer *Registry, syncChunkStore storage.SyncChunkStore) {
streamer.RegisterServerFunc("SYNC", func(_ *Peer, t string, _ bool) (Server, error) {
po, err := ParseSyncBinKey(t)
if err != nil {
return nil, err
}
return NewSwarmSyncerServer(po, syncChunkStore)
})
// streamer.RegisterServerFunc(stream, func(p *Peer) (Server, error) {
// return NewOutgoingProvableSwarmSyncer(po, db)
// })
}
// Close needs to be called on a stream server
func (s *SwarmSyncerServer) Close() {
close(s.quit)
}
// GetData retrieves the actual chunk from netstore
func (s *SwarmSyncerServer) GetData(ctx context.Context, key []byte) ([]byte, error) {
chunk, err := s.store.Get(ctx, storage.Address(key))
if err != nil {
return nil, err
}
return chunk.Data(), nil
}
// SessionIndex returns current storage bin (po) index.
func (s *SwarmSyncerServer) SessionIndex() (uint64, error) {
return s.store.BinIndex(s.po), nil
}
// GetBatch retrieves the next batch of hashes from the dbstore
func (s *SwarmSyncerServer) SetNextBatch(from, to uint64) ([]byte, uint64, uint64, *HandoverProof, error) {
var batch []byte
i := 0
var ticker *time.Ticker
defer func() {
if ticker != nil {
ticker.Stop()
}
}()
var wait bool
for {
if wait {
if ticker == nil {
ticker = time.NewTicker(1000 * time.Millisecond)
}
select {
case <-ticker.C:
case <-s.quit:
return nil, 0, 0, nil, nil
}
}
metrics.GetOrRegisterCounter("syncer.setnextbatch.iterator", nil).Inc(1)
err := s.store.Iterator(from, to, s.po, func(key storage.Address, idx uint64) bool {
batch = append(batch, key[:]...)
i++
to = idx
return i < BatchSize
})
if err != nil {
return nil, 0, 0, nil, err
}
if len(batch) > 0 {
break
}
wait = true
}
log.Trace("Swarm syncer offer batch", "po", s.po, "len", i, "from", from, "to", to, "current store count", s.store.BinIndex(s.po))
return batch, from, to, nil, nil
}
// SwarmSyncerClient
type SwarmSyncerClient struct {
sessionAt uint64
nextC chan struct{}
sessionRoot storage.Address
sessionReader storage.LazySectionReader
retrieveC chan *storage.Chunk
storeC chan *storage.Chunk
store storage.SyncChunkStore
// chunker storage.Chunker
currentRoot storage.Address
requestFunc func(chunk *storage.Chunk)
end, start uint64
peer *Peer
stream Stream
}
// NewSwarmSyncerClient is a contructor for provable data exchange syncer
func NewSwarmSyncerClient(p *Peer, store storage.SyncChunkStore, stream Stream) (*SwarmSyncerClient, error) {
return &SwarmSyncerClient{
store: store,
peer: p,
stream: stream,
}, nil
}
// // NewIncomingProvableSwarmSyncer is a contructor for provable data exchange syncer
// func NewIncomingProvableSwarmSyncer(po int, priority int, index uint64, sessionAt uint64, intervals []uint64, sessionRoot storage.Address, chunker *storage.PyramidChunker, store storage.ChunkStore, p Peer) *SwarmSyncerClient {
// retrieveC := make(storage.Chunk, chunksCap)
// RunChunkRequestor(p, retrieveC)
// storeC := make(storage.Chunk, chunksCap)
// RunChunkStorer(store, storeC)
// s := &SwarmSyncerClient{
// po: po,
// priority: priority,
// sessionAt: sessionAt,
// start: index,
// end: index,
// nextC: make(chan struct{}, 1),
// intervals: intervals,
// sessionRoot: sessionRoot,
// sessionReader: chunker.Join(sessionRoot, retrieveC),
// retrieveC: retrieveC,
// storeC: storeC,
// }
// return s
// }
// // StartSyncing is called on the Peer to start the syncing process
// // the idea is that it is called only after kademlia is close to healthy
// func StartSyncing(s *Streamer, peerId enode.ID, po uint8, nn bool) {
// lastPO := po
// if nn {
// lastPO = maxPO
// }
//
// for i := po; i <= lastPO; i++ {
// s.Subscribe(peerId, "SYNC", newSyncLabel("LIVE", po), 0, 0, High, true)
// s.Subscribe(peerId, "SYNC", newSyncLabel("HISTORY", po), 0, 0, Mid, false)
// }
// }
// RegisterSwarmSyncerClient registers the client constructor function for
// to handle incoming sync streams
func RegisterSwarmSyncerClient(streamer *Registry, store storage.SyncChunkStore) {
streamer.RegisterClientFunc("SYNC", func(p *Peer, t string, live bool) (Client, error) {
return NewSwarmSyncerClient(p, store, NewStream("SYNC", t, live))
})
}
// NeedData
func (s *SwarmSyncerClient) NeedData(ctx context.Context, key []byte) (wait func(context.Context) error) {
return s.store.FetchFunc(ctx, key)
}
// BatchDone
func (s *SwarmSyncerClient) BatchDone(stream Stream, from uint64, hashes []byte, root []byte) func() (*TakeoverProof, error) {
// TODO: reenable this with putter/getter refactored code
// if s.chunker != nil {
// return func() (*TakeoverProof, error) { return s.TakeoverProof(stream, from, hashes, root) }
// }
return nil
}
func (s *SwarmSyncerClient) TakeoverProof(stream Stream, from uint64, hashes []byte, root storage.Address) (*TakeoverProof, error) {
// for provable syncer currentRoot is non-zero length
// TODO: reenable this with putter/getter
// if s.chunker != nil {
// if from > s.sessionAt { // for live syncing currentRoot is always updated
// //expRoot, err := s.chunker.Append(s.currentRoot, bytes.NewReader(hashes), s.retrieveC, s.storeC)
// expRoot, _, err := s.chunker.Append(s.currentRoot, bytes.NewReader(hashes), s.retrieveC)
// if err != nil {
// return nil, err
// }
// if !bytes.Equal(root, expRoot) {
// return nil, fmt.Errorf("HandoverProof mismatch")
// }
// s.currentRoot = root
// } else {
// expHashes := make([]byte, len(hashes))
// _, err := s.sessionReader.ReadAt(expHashes, int64(s.end*HashSize))
// if err != nil && err != io.EOF {
// return nil, err
// }
// if !bytes.Equal(expHashes, hashes) {
// return nil, errors.New("invalid proof")
// }
// }
// return nil, nil
// }
s.end += uint64(len(hashes)) / HashSize
takeover := &Takeover{
Stream: stream,
Start: s.start,
End: s.end,
Root: root,
}
// serialise and sign
return &TakeoverProof{
Takeover: takeover,
Sig: nil,
}, nil
}
func (s *SwarmSyncerClient) Close() {}
// base for parsing and formating sync bin key
// it must be 2 <= base <= 36
const syncBinKeyBase = 36
// FormatSyncBinKey returns a string representation of
// Kademlia bin number to be used as key for SYNC stream.
func FormatSyncBinKey(bin uint8) string {
return strconv.FormatUint(uint64(bin), syncBinKeyBase)
}
// ParseSyncBinKey parses the string representation
// and returns the Kademlia bin number.
func ParseSyncBinKey(s string) (uint8, error) {
bin, err := strconv.ParseUint(s, syncBinKeyBase, 8)
if err != nil {
return 0, err
}
return uint8(bin), nil
}
