gaspersic/go-ethereum
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

eth/downloader: prioritize block fetch based on chain position, cap memory use

Browse Source
This commit is contained in:
Péter Szilágyi
2015-05-06 15:32:53 +03:00
parent 97c37356fd
commit 4800c94392
11 changed files with 808 additions and 283 deletions
Download Patch File Download Diff File Expand all files Collapse all files

190
eth/downloader/downloader.go
View File

@ -11,11 +11,10 @@ import (
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"gopkg.in/fatih/set.v0"
)
const (
maxBlockFetch = 256 // Amount of max blocks to be fetched per chunk
maxBlockFetch = 128 // Amount of max blocks to be fetched per chunk
peerCountTimeout = 12 * time.Second // Amount of time it takes for the peer handler to ignore minDesiredPeerCount
hashTtl = 20 * time.Second // The amount of time it takes for a hash request to time out
)
@ -80,7 +79,7 @@ type Downloader struct {
func New(hasBlock hashCheckFn, getBlock getBlockFn) *Downloader {
downloader := &Downloader{
queue: newqueue(),
queue: newQueue(),
peers: make(peers),
hasBlock: hasBlock,
getBlock: getBlock,
@ -93,7 +92,7 @@ func New(hasBlock hashCheckFn, getBlock getBlockFn) *Downloader {
}
func (d *Downloader) Stats() (current int, max int) {
return d.queue.blockHashes.Size(), d.queue.fetchPool.Size() + d.queue.hashPool.Size()
return d.queue.Size()
}
func (d *Downloader) RegisterPeer(id string, hash common.Hash, getHashes hashFetcherFn, getBlocks blockFetcherFn) error {
@ -111,7 +110,7 @@ func (d *Downloader) RegisterPeer(id string, hash common.Hash, getHashes hashFet
return nil
}
// UnregisterPeer unregister's a peer. This will prevent any action from the specified peer.
// UnregisterPeer unregisters a peer. This will prevent any action from the specified peer.
func (d *Downloader) UnregisterPeer(id string) {
d.mu.Lock()
defer d.mu.Unlock()
@ -121,20 +120,20 @@ func (d *Downloader) UnregisterPeer(id string) {
delete(d.peers, id)
}
// SynchroniseWithPeer will select the peer and use it for synchronising. If an empty string is given
// it will use the best peer possible and synchronise if it's TD is higher than our own. If any of the
// SynchroniseWithPeer will select the peer and use it for synchronizing. If an empty string is given
// it will use the best peer possible and synchronize if it's TD is higher than our own. If any of the
// checks fail an error will be returned. This method is synchronous
func (d *Downloader) Synchronise(id string, hash common.Hash) error {
// Make sure it's doing neither. Once done we can restart the
// downloading process if the TD is higher. For now just get on
// with whatever is going on. This prevents unecessary switching.
// with whatever is going on. This prevents unnecessary switching.
if d.isBusy() {
return errBusy
}
// When a synchronisation attempt is made while the queue stil
// When a synchronization attempt is made while the queue still
// contains items we abort the sync attempt
if d.queue.size() > 0 {
if done, pend := d.queue.Size(); done+pend > 0 {
return errPendingQueue
}
@ -157,56 +156,23 @@ func (d *Downloader) Synchronise(id string, hash common.Hash) error {
// are processed. If the block count reaches zero and done is called
// we reset the queue for the next batch of incoming hashes and blocks.
func (d *Downloader) Done() {
d.queue.mu.Lock()
defer d.queue.mu.Unlock()
if len(d.queue.blocks) == 0 {
d.queue.resetNoTS()
}
d.queue.Done()
}
// TakeBlocks takes blocks from the queue and yields them to the blockTaker handler
// it's possible it yields no blocks
func (d *Downloader) TakeBlocks() types.Blocks {
d.queue.mu.Lock()
defer d.queue.mu.Unlock()
var blocks types.Blocks
if len(d.queue.blocks) > 0 {
// Make sure the parent hash is known
if d.queue.blocks[0] != nil && !d.hasBlock(d.queue.blocks[0].ParentHash()) {
return nil
}
for _, block := range d.queue.blocks {
if block == nil {
break
}
blocks = append(blocks, block)
}
d.queue.blockOffset += len(blocks)
// delete the blocks from the slice and let them be garbage collected
// without this slice trick the blocks would stay in memory until nil
// would be assigned to d.queue.blocks
copy(d.queue.blocks, d.queue.blocks[len(blocks):])
for k, n := len(d.queue.blocks)-len(blocks), len(d.queue.blocks); k < n; k++ {
d.queue.blocks[k] = nil
}
d.queue.blocks = d.queue.blocks[:len(d.queue.blocks)-len(blocks)]
//d.queue.blocks = d.queue.blocks[len(blocks):]
if len(d.queue.blocks) == 0 {
d.queue.blocks = nil
}
// Check that there are blocks available and its parents are known
head := d.queue.GetHeadBlock()
if head == nil || !d.hasBlock(head.ParentHash()) {
return nil
}
return blocks
// Retrieve a full batch of blocks
return d.queue.TakeBlocks(head)
}
func (d *Downloader) Has(hash common.Hash) bool {
return d.queue.has(hash)
return d.queue.Has(hash)
}
func (d *Downloader) getFromPeer(p *peer, hash common.Hash, ignoreInitial bool) (err error) {
@ -214,7 +180,7 @@ func (d *Downloader) getFromPeer(p *peer, hash common.Hash, ignoreInitial bool)
defer func() {
// reset on error
if err != nil {
d.queue.reset()
d.queue.Reset()
}
}()
@ -244,7 +210,7 @@ func (d *Downloader) startFetchingHashes(p *peer, h common.Hash, ignoreInitial b
atomic.StoreInt32(&d.fetchingHashes, 1)
defer atomic.StoreInt32(&d.fetchingHashes, 0)
if d.queue.has(h) {
if d.queue.Has(h) { // TODO: Is this possible? Shouldn't queue be empty for startFetchingHashes to be even called?
return errAlreadyInPool
}
@ -256,7 +222,7 @@ func (d *Downloader) startFetchingHashes(p *peer, h common.Hash, ignoreInitial b
// In such circumstances we don't need to download the block so don't add it to the queue.
if !ignoreInitial {
// Add the hash to the queue first
d.queue.hashPool.Add(h)
d.queue.Insert([]common.Hash{h})
}
// Get the first batch of hashes
p.getHashes(h)
@ -273,7 +239,7 @@ out:
for {
select {
case hashPack := <-d.hashCh:
// make sure the active peer is giving us the hashes
// Make sure the active peer is giving us the hashes
if hashPack.peerId != activePeer.id {
glog.V(logger.Debug).Infof("Received hashes from incorrect peer(%s)\n", hashPack.peerId)
break
@ -281,43 +247,37 @@ out:
failureResponseTimer.Reset(hashTtl)
var (
hashes = hashPack.hashes
done bool // determines whether we're done fetching hashes (i.e. common hash found)
)
hashSet := set.New()
for _, hash = range hashes {
if d.hasBlock(hash) || d.queue.blockHashes.Has(hash) {
glog.V(logger.Debug).Infof("Found common hash %x\n", hash[:4])
// Make sure the peer actually gave something valid
if len(hashPack.hashes) == 0 {
glog.V(logger.Debug).Infof("Peer (%s) responded with empty hash set\n", activePeer.id)
d.queue.Reset()
return errEmptyHashSet
}
// Determine if we're done fetching hashes (queue up all pending), and continue if not done
done, index := false, 0
for index, hash = range hashPack.hashes {
if d.hasBlock(hash) || d.queue.GetBlock(hash) != nil {
glog.V(logger.Debug).Infof("Found common hash %x\n", hash[:4])
hashPack.hashes = hashPack.hashes[:index]
done = true
break
}
hashSet.Add(hash)
}
d.queue.put(hashSet)
d.queue.Insert(hashPack.hashes)
// Add hashes to the chunk set
if len(hashes) == 0 { // Make sure the peer actually gave you something valid
glog.V(logger.Debug).Infof("Peer (%s) responded with empty hash set\n", activePeer.id)
d.queue.reset()
return errEmptyHashSet
} else if !done { // Check if we're done fetching
// Get the next set of hashes
if !done {
activePeer.getHashes(hash)
} else { // we're done
// The offset of the queue is determined by the highest known block
var offset int
if block := d.getBlock(hash); block != nil {
offset = int(block.NumberU64() + 1)
}
// allocate proper size for the queueue
d.queue.alloc(offset, d.queue.hashPool.Size())
break out
continue
}
// We're done, allocate the download cache and proceed pulling the blocks
offset := 0
if block := d.getBlock(hash); block != nil {
offset = int(block.NumberU64() + 1)
}
d.queue.Alloc(offset)
break out
case <-failureResponseTimer.C:
glog.V(logger.Debug).Infof("Peer (%s) didn't respond in time for hash request\n", p.id)
@ -326,7 +286,7 @@ out:
// already fetched hash list. This can't guarantee 100% correctness but does
// a fair job. This is always either correct or false incorrect.
for id, peer := range d.peers {
if d.queue.hashPool.Has(peer.recentHash) && !attemptedPeers[id] {
if d.queue.Has(peer.recentHash) && !attemptedPeers[id] {
p = peer
break
}
@ -335,7 +295,7 @@ out:
// if all peers have been tried, abort the process entirely or if the hash is
// the zero hash.
if p == nil || (hash == common.Hash{}) {
d.queue.reset()
d.queue.Reset()
return errTimeout
}
@ -346,13 +306,14 @@ out:
glog.V(logger.Debug).Infof("Hash fetching switched to new peer(%s)\n", p.id)
}
}
glog.V(logger.Detail).Infof("Downloaded hashes (%d) in %v\n", d.queue.hashPool.Size(), time.Since(start))
glog.V(logger.Detail).Infof("Downloaded hashes (%d) in %v\n", d.queue.Pending(), time.Since(start))
return nil
}
func (d *Downloader) startFetchingBlocks(p *peer) error {
glog.V(logger.Detail).Infoln("Downloading", d.queue.hashPool.Size(), "block(s)")
glog.V(logger.Detail).Infoln("Downloading", d.queue.Pending(), "block(s)")
atomic.StoreInt32(&d.downloadingBlocks, 1)
defer atomic.StoreInt32(&d.downloadingBlocks, 0)
// Defer the peer reset. This will empty the peer requested set
@ -362,7 +323,7 @@ func (d *Downloader) startFetchingBlocks(p *peer) error {
start := time.Now()
// default ticker for re-fetching blocks everynow and then
// default ticker for re-fetching blocks every now and then
ticker := time.NewTicker(20 * time.Millisecond)
out:
for {
@ -371,7 +332,7 @@ out:
// If the peer was previously banned and failed to deliver it's pack
// in a reasonable time frame, ignore it's message.
if d.peers[blockPack.peerId] != nil {
err := d.queue.deliver(blockPack.peerId, blockPack.blocks)
err := d.queue.Deliver(blockPack.peerId, blockPack.blocks)
if err != nil {
glog.V(logger.Debug).Infof("deliver failed for peer %s: %v\n", blockPack.peerId, err)
// FIXME d.UnregisterPeer(blockPack.peerId)
@ -385,46 +346,49 @@ out:
d.peers.setState(blockPack.peerId, idleState)
}
case <-ticker.C:
// after removing bad peers make sure we actually have suffucient peer left to keep downlading
// after removing bad peers make sure we actually have sufficient peer left to keep downloading
if len(d.peers) == 0 {
d.queue.reset()
d.queue.Reset()
return errNoPeers
}
// If there are unrequested hashes left start fetching
// from the available peers.
if d.queue.hashPool.Size() > 0 {
if d.queue.Pending() > 0 {
// Throttle the download if block cache is full and waiting processing
if d.queue.Throttle() {
continue
}
availablePeers := d.peers.get(idleState)
for _, peer := range availablePeers {
// Get a possible chunk. If nil is returned no chunk
// could be returned due to no hashes available.
chunk := d.queue.get(peer, maxBlockFetch)
if chunk == nil {
request := d.queue.Reserve(peer, maxBlockFetch)
if request == nil {
continue
}
// XXX make fetch blocking.
// Fetch the chunk and check for error. If the peer was somehow
// already fetching a chunk due to a bug, it will be returned to
// the queue
if err := peer.fetch(chunk); err != nil {
if err := peer.fetch(request); err != nil {
// log for tracing
glog.V(logger.Debug).Infof("peer %s received double work (state = %v)\n", peer.id, peer.state)
d.queue.put(chunk.hashes)
d.queue.Cancel(request)
}
}
// make sure that we have peers available for fetching. If all peers have been tried
// and all failed throw an error
if len(d.queue.fetching) == 0 {
d.queue.reset()
if d.queue.InFlight() == 0 {
d.queue.Reset()
return fmt.Errorf("%v peers avaialable = %d. total peers = %d. hashes needed = %d", errPeersUnavailable, len(availablePeers), len(d.peers), d.queue.hashPool.Size())
return fmt.Errorf("%v peers avaialable = %d. total peers = %d. hashes needed = %d", errPeersUnavailable, len(availablePeers), len(d.peers), d.queue.Pending())
}
} else if len(d.queue.fetching) == 0 {
// When there are no more queue and no more `fetching`. We can
} else if d.queue.InFlight() == 0 {
// When there are no more queue and no more in flight, We can
// safely assume we're done. Another part of the process will check
// for parent errors and will re-request anything that's missing
break out
@ -434,27 +398,13 @@ out:
// that badly or poorly behave are removed from the peer set (not banned).
// Bad peers are excluded from the available peer set and therefor won't be
// reused. XXX We could re-introduce peers after X time.
d.queue.mu.Lock()
var badPeers []string
for pid, chunk := range d.queue.fetching {
if time.Since(chunk.itime) > blockTtl {
badPeers = append(badPeers, pid)
// remove peer as good peer from peer list
// FIXME d.UnregisterPeer(pid)
}
}
d.queue.mu.Unlock()
badPeers := d.queue.Expire(blockTtl)
for _, pid := range badPeers {
// A nil chunk is delivered so that the chunk's hashes are given
// back to the queue objects. When hashes are put back in the queue
// other (decent) peers can pick them up.
// XXX We could make use of a reputation system here ranking peers
// in their performance
// 1) Time for them to respond;
// 2) Measure their speed;
// 3) Amount and availability.
d.queue.deliver(pid, nil)
if peer := d.peers[pid]; peer != nil {
peer.demote()
peer.reset()
@ -486,7 +436,7 @@ func (d *Downloader) AddHashes(id string, hashes []common.Hash) error {
if glog.V(logger.Detail) && len(hashes) != 0 {
from, to := hashes[0], hashes[len(hashes)-1]
glog.Infof("adding %d (T=%d) hashes [ %x / %x ] from: %s\n", len(hashes), d.queue.hashPool.Size(), from[:4], to[:4], id)
glog.Infof("adding %d (T=%d) hashes [ %x / %x ] from: %s\n", len(hashes), d.queue.Pending(), from[:4], to[:4], id)
}
d.hashCh <- hashPack{id, hashes}

4
eth/downloader/downloader_test.go
View File

@ -128,7 +128,7 @@ func TestDownload(t *testing.T) {
t.Error("download error", err)
}
inqueue := len(tester.downloader.queue.blocks)
inqueue := len(tester.downloader.queue.blockCache)
if inqueue != targetBlocks {
t.Error("expected", targetBlocks, "have", inqueue)
}
@ -151,7 +151,7 @@ func TestMissing(t *testing.T) {
t.Error("download error", err)
}
inqueue := len(tester.downloader.queue.blocks)
inqueue := len(tester.downloader.queue.blockCache)
if inqueue != targetBlocks {
t.Error("expected", targetBlocks, "have", inqueue)
}

15
eth/downloader/peer.go
View File

@ -78,7 +78,7 @@ func newPeer(id string, hash common.Hash, getHashes hashFetcherFn, getBlocks blo
}
// fetch a chunk using the peer
func (p *peer) fetch(chunk *chunk) error {
func (p *peer) fetch(request *fetchRequest) error {
p.mu.Lock()
defer p.mu.Unlock()
@ -88,13 +88,12 @@ func (p *peer) fetch(chunk *chunk) error {
// set working state
p.state = workingState
// convert the set to a fetchable slice
hashes, i := make([]common.Hash, chunk.hashes.Size()), 0
chunk.hashes.Each(func(v interface{}) bool {
hashes[i] = v.(common.Hash)
i++
return true
})
// Convert the hash set to a fetchable slice
hashes := make([]common.Hash, 0, len(request.Hashes))
for hash, _ := range request.Hashes {
hashes = append(hashes, hash)
}
p.getBlocks(hashes)
return nil

436
eth/downloader/queue.go
View File

@ -1,201 +1,349 @@
package downloader
import (
"errors"
"fmt"
"math"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"gopkg.in/fatih/set.v0"
"gopkg.in/karalabe/cookiejar.v2/collections/prque"
)
const (
blockCacheLimit = 4096 // Maximum number of blocks to cache before throttling the download
)
// fetchRequest is a currently running block retrieval operation.
type fetchRequest struct {
Peer *peer // Peer to which the request was sent
Hashes map[common.Hash]int // Requested hashes with their insertion index (priority)
Time time.Time // Time when the request was made
}
// queue represents hashes that are either need fetching or are being fetched
type queue struct {
hashPool *set.Set
fetchPool *set.Set
blockHashes *set.Set
hashPool map[common.Hash]int // Pending hashes, mapping to their insertion index (priority)
hashQueue *prque.Prque // Priority queue of the block hashes to fetch
hashCounter int // Counter indexing the added hashes to ensure retrieval order
mu sync.Mutex
fetching map[string]*chunk
pendPool map[string]*fetchRequest // Currently pending block retrieval operations
pendCount int // Number of pending block fetches (to throttle the download)
blockOffset int
blocks []*types.Block
blockPool map[common.Hash]int // Hash-set of the downloaded data blocks, mapping to cache indexes
blockCache []*types.Block // Downloaded but not yet delivered blocks
blockOffset int // Offset of the first cached block in the block-chain
lock sync.RWMutex
}
func newqueue() *queue {
// newQueue creates a new download queue for scheduling block retrieval.
func newQueue() *queue {
return &queue{
hashPool: set.New(),
fetchPool: set.New(),
blockHashes: set.New(),
fetching: make(map[string]*chunk),
hashPool: make(map[common.Hash]int),
hashQueue: prque.New(),
pendPool: make(map[string]*fetchRequest),
blockPool: make(map[common.Hash]int),
}
}
func (c *queue) reset() {
c.mu.Lock()
defer c.mu.Unlock()
// Reset clears out the queue contents.
func (q *queue) Reset() {
q.lock.Lock()
defer q.lock.Unlock()
c.resetNoTS()
}
func (c *queue) resetNoTS() {
c.blockOffset = 0
c.hashPool.Clear()
c.fetchPool.Clear()
c.blockHashes.Clear()
c.blocks = nil
c.fetching = make(map[string]*chunk)
q.hashPool = make(map[common.Hash]int)
q.hashQueue.Reset()
q.hashCounter = 0
q.pendPool = make(map[string]*fetchRequest)
q.pendCount = 0
q.blockPool = make(map[common.Hash]int)
q.blockOffset = 0
q.blockCache = nil
}
func (c *queue) size() int {
return c.hashPool.Size() + c.blockHashes.Size() + c.fetchPool.Size()
}
// Done checks if all the downloads have been retrieved, wiping the queue.
func (q *queue) Done() {
q.lock.Lock()
defer q.lock.Unlock()
// reserve a `max` set of hashes for `p` peer.
func (c *queue) get(p *peer, max int) *chunk {
c.mu.Lock()
defer c.mu.Unlock()
// return nothing if the pool has been depleted
if c.hashPool.Size() == 0 {
return nil
if len(q.blockCache) == 0 {
q.Reset()
}
}
limit := int(math.Min(float64(max), float64(c.hashPool.Size())))
// Create a new set of hashes
hashes, i := set.New(), 0
c.hashPool.Each(func(v interface{}) bool {
// break on limit
if i == limit {
return false
}
// skip any hashes that have previously been requested from the peer
if p.ignored.Has(v) {
return true
}
// Size retrieves the number of hashes in the queue, returning separately for
// pending and already downloaded.
func (q *queue) Size() (int, int) {
q.lock.RLock()
defer q.lock.RUnlock()
hashes.Add(v)
i++
return len(q.hashPool), len(q.blockPool)
}
// Pending retrieves the number of hashes pending for retrieval.
func (q *queue) Pending() int {
q.lock.RLock()
defer q.lock.RUnlock()
return q.hashQueue.Size()
}
// InFlight retrieves the number of fetch requests currently in flight.
func (q *queue) InFlight() int {
q.lock.RLock()
defer q.lock.RUnlock()
return len(q.pendPool)
}
// Throttle checks if the download should be throttled (active block fetches
// exceed block cache).
func (q *queue) Throttle() bool {
q.lock.RLock()
defer q.lock.RUnlock()
return q.pendCount >= len(q.blockCache)-len(q.blockPool)
}
// Has checks if a hash is within the download queue or not.
func (q *queue) Has(hash common.Hash) bool {
q.lock.RLock()
defer q.lock.RUnlock()
if _, ok := q.hashPool[hash]; ok {
return true
})
// if no hashes can be requested return a nil chunk
if hashes.Size() == 0 {
return nil
}
// remove the fetchable hashes from hash pool
c.hashPool.Separate(hashes)
c.fetchPool.Merge(hashes)
// Create a new chunk for the seperated hashes. The time is being used
// to reset the chunk (timeout)
chunk := &chunk{p, hashes, time.Now()}
// register as 'fetching' state
c.fetching[p.id] = chunk
// create new chunk for peer
return chunk
if _, ok := q.blockPool[hash]; ok {
return true
}
return false
}
func (c *queue) has(hash common.Hash) bool {
return c.hashPool.Has(hash) || c.fetchPool.Has(hash) || c.blockHashes.Has(hash)
// Insert adds a set of hashes for the download queue for scheduling.
func (q *queue) Insert(hashes []common.Hash) {
q.lock.Lock()
defer q.lock.Unlock()
// Insert all the hashes prioritized in the arrival order
for i, hash := range hashes {
index := q.hashCounter + i
q.hashPool[hash] = index
q.hashQueue.Push(hash, float32(index)) // Highest gets schedules first
}
// Update the hash counter for the next batch of inserts
q.hashCounter += len(hashes)
}
func (c *queue) getBlock(hash common.Hash) *types.Block {
c.mu.Lock()
defer c.mu.Unlock()
// GetHeadBlock retrieves the first block from the cache, or nil if it hasn't
// been downloaded yet (or simply non existent).
func (q *queue) GetHeadBlock() *types.Block {
q.lock.RLock()
defer q.lock.RUnlock()
if !c.blockHashes.Has(hash) {
if len(q.blockCache) == 0 {
return nil
}
return q.blockCache[0]
}
for _, block := range c.blocks {
if block.Hash() == hash {
return block
}
// GetBlock retrieves a downloaded block, or nil if non-existent.
func (q *queue) GetBlock(hash common.Hash) *types.Block {
q.lock.RLock()
defer q.lock.RUnlock()
// Short circuit if the block hasn't been downloaded yet
index, ok := q.blockPool[hash]
if !ok {
return nil
}
// Return the block if it's still available in the cache
if q.blockOffset <= index && index < q.blockOffset+len(q.blockCache) {
return q.blockCache[index-q.blockOffset]
}
return nil
}
// deliver delivers a chunk to the queue that was requested of the peer
func (c *queue) deliver(id string, blocks []*types.Block) (err error) {
c.mu.Lock()
defer c.mu.Unlock()
// TakeBlocks retrieves and permanently removes a batch of blocks from the cache.
// The head parameter is required to prevent a race condition where concurrent
// takes may fail parent verifications.
func (q *queue) TakeBlocks(head *types.Block) types.Blocks {
q.lock.Lock()
defer q.lock.Unlock()
chunk := c.fetching[id]
// If the chunk was never requested simply ignore it
if chunk != nil {
delete(c.fetching, id)
// check the length of the returned blocks. If the length of blocks is 0
// we'll assume the peer doesn't know about the chain.
if len(blocks) == 0 {
// So we can ignore the blocks we didn't know about
chunk.peer.ignored.Merge(chunk.hashes)
// Short circuit if the head block's different
if len(q.blockCache) == 0 || q.blockCache[0] != head {
return nil
}
// Otherwise accumulate all available blocks
var blocks types.Blocks
for _, block := range q.blockCache {
if block == nil {
break
}
blocks = append(blocks, block)
delete(q.blockPool, block.Hash())
}
// Delete the blocks from the slice and let them be garbage collected
// without this slice trick the blocks would stay in memory until nil
// would be assigned to q.blocks
copy(q.blockCache, q.blockCache[len(blocks):])
for k, n := len(q.blockCache)-len(blocks), len(q.blockCache); k < n; k++ {
q.blockCache[k] = nil
}
q.blockOffset += len(blocks)
// Add the blocks
for i, block := range blocks {
// See (1) for future limitation
n := int(block.NumberU64()) - c.blockOffset
if n > len(c.blocks) || n < 0 {
// set the error and set the blocks which could be processed
// abort the rest of the blocks (FIXME this could be improved)
err = fmt.Errorf("received block which overflow (N=%v O=%v)", block.Number(), c.blockOffset)
blocks = blocks[:i]
break
return blocks
}
// Reserve reserves a set of hashes for the given peer, skipping any previously
// failed download.
func (q *queue) Reserve(p *peer, max int) *fetchRequest {
q.lock.Lock()
defer q.lock.Unlock()
// Short circuit if the pool has been depleted
if q.hashQueue.Empty() {
return nil
}
// Retrieve a batch of hashes, skipping previously failed ones
send := make(map[common.Hash]int)
skip := make(map[common.Hash]int)
for len(send) < max && !q.hashQueue.Empty() {
hash, priority := q.hashQueue.Pop()
if p.ignored.Has(hash) {
skip[hash.(common.Hash)] = int(priority)
} else {
send[hash.(common.Hash)] = int(priority)
}
}
// Merge all the skipped hashes back
for hash, index := range skip {
q.hashQueue.Push(hash, float32(index))
}
// Assemble and return the block download request
if len(send) == 0 {
return nil
}
request := &fetchRequest{
Peer: p,
Hashes: send,
Time: time.Now(),
}
q.pendPool[p.id] = request
q.pendCount += len(request.Hashes)
return request
}
// Cancel aborts a fetch request, returning all pending hashes to the queue.
func (q *queue) Cancel(request *fetchRequest) {
q.lock.Lock()
defer q.lock.Unlock()
for hash, index := range request.Hashes {
q.hashQueue.Push(hash, float32(index))
}
delete(q.pendPool, request.Peer.id)
q.pendCount -= len(request.Hashes)
}
// Expire checks for in flight requests that exceeded a timeout allowance,
// canceling them and returning the responsible peers for penalization.
func (q *queue) Expire(timeout time.Duration) []string {
q.lock.Lock()
defer q.lock.Unlock()
// Iterate over the expired requests and return each to the queue
peers := []string{}
for id, request := range q.pendPool {
if time.Since(request.Time) > timeout {
for hash, index := range request.Hashes {
q.hashQueue.Push(hash, float32(index))
}
c.blocks[n] = block
q.pendCount -= len(request.Hashes)
peers = append(peers, id)
}
// seperate the blocks and the hashes
blockHashes := chunk.fetchedHashes(blocks)
// merge block hashes
c.blockHashes.Merge(blockHashes)
// Add back whatever couldn't be delivered
c.hashPool.Merge(chunk.hashes)
// Remove the hashes from the fetch pool
c.fetchPool.Separate(chunk.hashes)
}
return
}
func (c *queue) alloc(offset, size int) {
c.mu.Lock()
defer c.mu.Unlock()
if c.blockOffset < offset {
c.blockOffset = offset
// Remove the expired requests from the pending pool
for _, id := range peers {
delete(q.pendPool, id)
}
return peers
}
// (1) XXX at some point we could limit allocation to memory and use the disk
// to store future blocks.
if len(c.blocks) < size {
c.blocks = append(c.blocks, make([]*types.Block, size)...)
// Deliver injects a block retrieval response into the download queue.
func (q *queue) Deliver(id string, blocks []*types.Block) (err error) {
q.lock.Lock()
defer q.lock.Unlock()
// Short circuit if the blocks were never requested
request := q.pendPool[id]
if request == nil {
return errors.New("no fetches pending")
}
}
delete(q.pendPool, id)
// puts puts sets of hashes on to the queue for fetching
func (c *queue) put(hashes *set.Set) {
c.mu.Lock()
defer c.mu.Unlock()
// Mark all the hashes in the request as non-pending
q.pendCount -= len(request.Hashes)
c.hashPool.Merge(hashes)
}
type chunk struct {
peer *peer
hashes *set.Set
itime time.Time
}
func (ch *chunk) fetchedHashes(blocks []*types.Block) *set.Set {
fhashes := set.New()
// If no blocks were retrieved, mark them as unavailable for the origin peer
if len(blocks) == 0 {
for hash, _ := range request.Hashes {
request.Peer.ignored.Add(hash)
}
}
// Iterate over the downloaded blocks and add each of them
errs := make([]error, 0)
for _, block := range blocks {
fhashes.Add(block.Hash())
}
ch.hashes.Separate(fhashes)
// Skip any blocks that fall outside the cache range
index := int(block.NumberU64()) - q.blockOffset
if index >= len(q.blockCache) || index < 0 {
//fmt.Printf("block cache overflown (N=%v O=%v, C=%v)", block.Number(), q.blockOffset, len(q.blockCache))
continue
}
// Skip any blocks that were not requested
hash := block.Hash()
if _, ok := request.Hashes[hash]; !ok {
errs = append(errs, fmt.Errorf("non-requested block %v", hash))
continue
}
// Otherwise merge the block and mark the hash block
q.blockCache[index] = block
return fhashes
delete(request.Hashes, hash)
delete(q.hashPool, hash)
q.blockPool[hash] = int(block.NumberU64())
}
// Return all failed fetches to the queue
for hash, index := range request.Hashes {
q.hashQueue.Push(hash, float32(index))
}
if len(errs) != 0 {
return fmt.Errorf("multiple failures: %v", errs)
}
return nil
}
// Alloc ensures that the block cache is the correct size, given a starting
// offset, and a memory cap.
func (q *queue) Alloc(offset int) {
q.lock.Lock()
defer q.lock.Unlock()
if q.blockOffset < offset {
q.blockOffset = offset
}
size := len(q.hashPool)
if size > blockCacheLimit {
size = blockCacheLimit
}
if len(q.blockCache) < size {
q.blockCache = append(q.blockCache, make([]*types.Block, size-len(q.blockCache))...)
}
}

17
eth/downloader/queue_test.go
View File

@ -32,31 +32,30 @@ func createBlocksFromHashSet(hashes *set.Set) []*types.Block {
}
func TestChunking(t *testing.T) {
queue := newqueue()
queue := newQueue()
peer1 := newPeer("peer1", common.Hash{}, nil, nil)
peer2 := newPeer("peer2", common.Hash{}, nil, nil)
// 99 + 1 (1 == known genesis hash)
hashes := createHashes(0, 99)
hashSet := createHashSet(hashes)
queue.put(hashSet)
queue.Insert(hashes)
chunk1 := queue.get(peer1, 99)
chunk1 := queue.Reserve(peer1, 99)
if chunk1 == nil {
t.Errorf("chunk1 is nil")
t.FailNow()
}
chunk2 := queue.get(peer2, 99)
chunk2 := queue.Reserve(peer2, 99)
if chunk2 == nil {
t.Errorf("chunk2 is nil")
t.FailNow()
}
if chunk1.hashes.Size() != 99 {
t.Error("expected chunk1 hashes to be 99, got", chunk1.hashes.Size())
if len(chunk1.Hashes) != 99 {
t.Error("expected chunk1 hashes to be 99, got", len(chunk1.Hashes))
}
if chunk2.hashes.Size() != 1 {
t.Error("expected chunk1 hashes to be 1, got", chunk2.hashes.Size())
if len(chunk2.Hashes) != 1 {
t.Error("expected chunk1 hashes to be 1, got", len(chunk2.Hashes))
}
}