mirror of
https://gitlab.com/pulsechaincom/erigon-pulse.git
synced 2024-12-24 12:37:16 +00:00
310 lines
9.1 KiB
Go
310 lines
9.1 KiB
Go
// Package fetcher contains the block announcement based synchonisation.
|
|
package fetcher
|
|
|
|
import (
|
|
"errors"
|
|
"math/rand"
|
|
"time"
|
|
|
|
"github.com/ethereum/go-ethereum/common"
|
|
"github.com/ethereum/go-ethereum/core/types"
|
|
"github.com/ethereum/go-ethereum/logger"
|
|
"github.com/ethereum/go-ethereum/logger/glog"
|
|
"gopkg.in/karalabe/cookiejar.v2/collections/prque"
|
|
)
|
|
|
|
const (
|
|
arriveTimeout = 500 * time.Millisecond // Time allowance before an announced block is explicitly requested
|
|
fetchTimeout = 5 * time.Second // Maximum alloted time to return an explicitly requested block
|
|
maxQueueDist = 256 // Maximum allowed distance from the chain head to queue
|
|
)
|
|
|
|
var (
|
|
errTerminated = errors.New("terminated")
|
|
)
|
|
|
|
// hashCheckFn is a callback type for verifying a hash's presence in the local chain.
|
|
type hashCheckFn func(common.Hash) bool
|
|
|
|
// blockRequesterFn is a callback type for sending a block retrieval request.
|
|
type blockRequesterFn func([]common.Hash) error
|
|
|
|
// blockImporterFn is a callback type for trying to inject a block into the local chain.
|
|
type blockImporterFn func(peer string, block *types.Block) error
|
|
|
|
// chainHeightFn is a callback type to retrieve the current chain height.
|
|
type chainHeightFn func() uint64
|
|
|
|
// announce is the hash notification of the availability of a new block in the
|
|
// network.
|
|
type announce struct {
|
|
hash common.Hash // Hash of the block being announced
|
|
time time.Time // Timestamp of the announcement
|
|
|
|
origin string // Identifier of the peer originating the notification
|
|
fetch blockRequesterFn // Fetcher function to retrieve
|
|
}
|
|
|
|
// inject represents a schedules import operation.
|
|
type inject struct {
|
|
origin string
|
|
block *types.Block
|
|
}
|
|
|
|
// Fetcher is responsible for accumulating block announcements from various peers
|
|
// and scheduling them for retrieval.
|
|
type Fetcher struct {
|
|
// Various event channels
|
|
notify chan *announce
|
|
insert chan *inject
|
|
filter chan chan []*types.Block
|
|
quit chan struct{}
|
|
|
|
// Callbacks
|
|
hasBlock hashCheckFn // Checks if a block is present in the chain
|
|
importBlock blockImporterFn // Injects a block from an origin peer into the chain
|
|
chainHeight chainHeightFn // Retrieves the current chain's height
|
|
}
|
|
|
|
// New creates a block fetcher to retrieve blocks based on hash announcements.
|
|
func New(hasBlock hashCheckFn, importBlock blockImporterFn, chainHeight chainHeightFn) *Fetcher {
|
|
return &Fetcher{
|
|
notify: make(chan *announce),
|
|
insert: make(chan *inject),
|
|
filter: make(chan chan []*types.Block),
|
|
quit: make(chan struct{}),
|
|
hasBlock: hasBlock,
|
|
importBlock: importBlock,
|
|
chainHeight: chainHeight,
|
|
}
|
|
}
|
|
|
|
// Start boots up the announcement based synchoniser, accepting and processing
|
|
// hash notifications and block fetches until termination requested.
|
|
func (f *Fetcher) Start() {
|
|
go f.loop()
|
|
}
|
|
|
|
// Stop terminates the announcement based synchroniser, canceling all pending
|
|
// operations.
|
|
func (f *Fetcher) Stop() {
|
|
close(f.quit)
|
|
}
|
|
|
|
// Notify announces the fetcher of the potential availability of a new block in
|
|
// the network.
|
|
func (f *Fetcher) Notify(peer string, hash common.Hash, time time.Time, fetcher blockRequesterFn) error {
|
|
block := &announce{
|
|
hash: hash,
|
|
time: time,
|
|
origin: peer,
|
|
fetch: fetcher,
|
|
}
|
|
select {
|
|
case f.notify <- block:
|
|
return nil
|
|
case <-f.quit:
|
|
return errTerminated
|
|
}
|
|
}
|
|
|
|
// Enqueue tries to fill gaps the the fetcher's future import queue.
|
|
func (f *Fetcher) Enqueue(peer string, block *types.Block) error {
|
|
op := &inject{
|
|
origin: peer,
|
|
block: block,
|
|
}
|
|
select {
|
|
case f.insert <- op:
|
|
return nil
|
|
case <-f.quit:
|
|
return errTerminated
|
|
}
|
|
}
|
|
|
|
// Filter extracts all the blocks that were explicitly requested by the fetcher,
|
|
// returning those that should be handled differently.
|
|
func (f *Fetcher) Filter(blocks types.Blocks) types.Blocks {
|
|
// Send the filter channel to the fetcher
|
|
filter := make(chan []*types.Block)
|
|
|
|
select {
|
|
case f.filter <- filter:
|
|
case <-f.quit:
|
|
return nil
|
|
}
|
|
// Request the filtering of the block list
|
|
select {
|
|
case filter <- blocks:
|
|
case <-f.quit:
|
|
return nil
|
|
}
|
|
// Retrieve the blocks remaining after filtering
|
|
select {
|
|
case blocks := <-filter:
|
|
return blocks
|
|
case <-f.quit:
|
|
return nil
|
|
}
|
|
}
|
|
|
|
// Loop is the main fetcher loop, checking and processing various notification
|
|
// events.
|
|
func (f *Fetcher) loop() {
|
|
announced := make(map[common.Hash][]*announce)
|
|
fetching := make(map[common.Hash]*announce)
|
|
|
|
// Create the priority queue and a matching presence set
|
|
queue := prque.New()
|
|
queued := make(map[common.Hash]struct{})
|
|
enqueue := func(peer string, block *types.Block) {
|
|
// Make sure the block isn't in some weird place
|
|
if f.chainHeight()+maxQueueDist < block.NumberU64() {
|
|
return
|
|
}
|
|
// If not, schedule the block for future import
|
|
hash := block.Hash()
|
|
if _, ok := queued[hash]; !ok {
|
|
queued[hash] = struct{}{}
|
|
queue.Push(&inject{origin: peer, block: block}, -float32(block.NumberU64()))
|
|
|
|
glog.V(logger.Detail).Infof("Peer %s: queued block %x, total %v", peer, hash.Bytes()[:4], queue.Size())
|
|
}
|
|
}
|
|
// Iterate the block fetching until a quit is requested
|
|
fetch := time.NewTimer(0)
|
|
done := make(chan common.Hash)
|
|
|
|
for {
|
|
// Clean up any expired block fetches
|
|
for hash, announce := range fetching {
|
|
if time.Since(announce.time) > fetchTimeout {
|
|
delete(announced, hash)
|
|
delete(fetching, hash)
|
|
}
|
|
}
|
|
// Import any queued blocks that could potentially fit
|
|
height := f.chainHeight()
|
|
for !queue.Empty() {
|
|
// If too high up the chain, continue later
|
|
op := queue.PopItem().(*inject)
|
|
if number := op.block.NumberU64(); number > height+1 {
|
|
queue.Push(op, -float32(op.block.NumberU64()))
|
|
break
|
|
}
|
|
// Otherwise if not known yet, try and import
|
|
hash := op.block.Hash()
|
|
delete(queued, hash)
|
|
if f.hasBlock(hash) {
|
|
continue
|
|
}
|
|
// Block may just fit, try to import it
|
|
glog.V(logger.Debug).Infof("Peer %s: importing block %x", op.origin, hash.Bytes()[:4])
|
|
go func() {
|
|
defer func() { done <- hash }()
|
|
|
|
if err := f.importBlock(op.origin, op.block); err != nil {
|
|
glog.V(logger.Detail).Infof("Peer %s: block %x import failed: %v", op.origin, hash.Bytes()[:4], err)
|
|
return
|
|
}
|
|
}()
|
|
}
|
|
// Wait for an outside event to occur
|
|
select {
|
|
case <-f.quit:
|
|
// Fetcher terminating, abort all operations
|
|
return
|
|
|
|
case notification := <-f.notify:
|
|
// A block was announced, schedule if it's not yet downloading
|
|
glog.V(logger.Debug).Infof("Peer %s: scheduling %x", notification.origin, notification.hash[:4])
|
|
if _, ok := fetching[notification.hash]; ok {
|
|
break
|
|
}
|
|
if len(announced) == 0 {
|
|
glog.V(logger.Detail).Infof("Scheduling fetch in %v, at %v", arriveTimeout-time.Since(notification.time), notification.time.Add(arriveTimeout))
|
|
fetch.Reset(arriveTimeout - time.Since(notification.time))
|
|
}
|
|
announced[notification.hash] = append(announced[notification.hash], notification)
|
|
|
|
case op := <-f.insert:
|
|
// A direct block insertion was requested, try and fill any pending gaps
|
|
enqueue(op.origin, op.block)
|
|
|
|
case hash := <-done:
|
|
// A pending import finished, remove all traces of the notification
|
|
delete(announced, hash)
|
|
delete(fetching, hash)
|
|
|
|
case <-fetch.C:
|
|
// At least one block's timer ran out, check for needing retrieval
|
|
request := make(map[string][]common.Hash)
|
|
|
|
for hash, announces := range announced {
|
|
if time.Since(announces[0].time) > arriveTimeout {
|
|
announce := announces[rand.Intn(len(announces))]
|
|
if !f.hasBlock(hash) {
|
|
request[announce.origin] = append(request[announce.origin], hash)
|
|
fetching[hash] = announce
|
|
}
|
|
delete(announced, hash)
|
|
}
|
|
}
|
|
// Send out all block requests
|
|
for peer, hashes := range request {
|
|
glog.V(logger.Debug).Infof("Peer %s: explicitly fetching %d blocks", peer, len(hashes))
|
|
go fetching[hashes[0]].fetch(hashes)
|
|
}
|
|
// Schedule the next fetch if blocks are still pending
|
|
if len(announced) > 0 {
|
|
nearest := time.Now()
|
|
for _, announces := range announced {
|
|
if nearest.After(announces[0].time) {
|
|
nearest = announces[0].time
|
|
}
|
|
}
|
|
glog.V(logger.Detail).Infof("Rescheduling fetch in %v, at %v", arriveTimeout-time.Since(nearest), nearest.Add(arriveTimeout))
|
|
fetch.Reset(arriveTimeout - time.Since(nearest))
|
|
}
|
|
|
|
case filter := <-f.filter:
|
|
// Blocks arrived, extract any explicit fetches, return all else
|
|
var blocks types.Blocks
|
|
select {
|
|
case blocks = <-filter:
|
|
case <-f.quit:
|
|
return
|
|
}
|
|
|
|
explicit, download := []*types.Block{}, []*types.Block{}
|
|
for _, block := range blocks {
|
|
hash := block.Hash()
|
|
|
|
// Filter explicitly requested blocks from hash announcements
|
|
if _, ok := fetching[hash]; ok {
|
|
// Discard if already imported by other means
|
|
if !f.hasBlock(hash) {
|
|
explicit = append(explicit, block)
|
|
} else {
|
|
delete(fetching, hash)
|
|
}
|
|
} else {
|
|
download = append(download, block)
|
|
}
|
|
}
|
|
|
|
select {
|
|
case filter <- download:
|
|
case <-f.quit:
|
|
return
|
|
}
|
|
// Schedule the retrieved blocks for ordered import
|
|
for _, block := range explicit {
|
|
if announce := fetching[block.Hash()]; announce != nil {
|
|
enqueue(announce.origin, block)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|