mirror of https://github.com/ethereum/go-ethereum
obscuren
10 years ago
parent
61db7a71dd
commit
acf8452c33
@ -0,0 +1,98 @@ |
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package downloader |
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import ( |
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"math" |
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"sync" |
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"time" |
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"github.com/ethereum/go-ethereum/core/types" |
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"gopkg.in/fatih/set.v0" |
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) |
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// queue represents hashes that are either need fetching or are being fetched
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type queue struct { |
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hashPool *set.Set |
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mu sync.Mutex |
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fetching map[string]*chunk |
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blocks []*types.Block |
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} |
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func newqueue() *queue { |
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return &queue{ |
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hashPool: set.New(), |
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fetching: make(map[string]*chunk), |
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} |
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} |
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// reserve a `max` set of hashes for `p` peer.
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func (c *queue) get(p *peer, max int) *chunk { |
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c.mu.Lock() |
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defer c.mu.Unlock() |
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// return nothing if the pool has been depleted
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if c.hashPool.Size() == 0 { |
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return nil |
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} |
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limit := int(math.Min(float64(max), float64(c.hashPool.Size()))) |
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// Create a new set of hashes
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hashes, i := set.New(), 0 |
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c.hashPool.Each(func(v interface{}) bool { |
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if i == limit { |
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return false |
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} |
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hashes.Add(v) |
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i++ |
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return true |
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}) |
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// remove the fetchable hashes from hash pool
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c.hashPool.Separate(hashes) |
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// Create a new chunk for the seperated hashes. The time is being used
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// to reset the chunk (timeout)
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chunk := &chunk{hashes, time.Now()} |
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// register as 'fetching' state
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c.fetching[p.id] = chunk |
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// create new chunk for peer
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return chunk |
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} |
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func (c *queue) deliver(id string, blocks []*types.Block) { |
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c.mu.Lock() |
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defer c.mu.Unlock() |
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chunk := c.fetching[id] |
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// If the chunk was never requested simply ignore it
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if chunk != nil { |
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delete(c.fetching, id) |
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// seperate the blocks and the hashes
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chunk.seperate(blocks) |
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// Add the blocks
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c.blocks = append(c.blocks, blocks...) |
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// Add back whatever couldn't be delivered
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c.hashPool.Merge(chunk.hashes) |
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} |
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} |
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func (c *queue) put(hashes *set.Set) { |
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c.mu.Lock() |
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defer c.mu.Unlock() |
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c.hashPool.Merge(hashes) |
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} |
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type chunk struct { |
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hashes *set.Set |
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itime time.Time |
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} |
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func (ch *chunk) seperate(blocks []*types.Block) { |
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for _, block := range blocks { |
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ch.hashes.Remove(block.Hash()) |
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} |
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} |
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@ -0,0 +1,328 @@ |
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package downloader |
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import ( |
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"math" |
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"math/big" |
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"sync" |
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"sync/atomic" |
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"time" |
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"github.com/ethereum/go-ethereum/common" |
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"github.com/ethereum/go-ethereum/core/types" |
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"github.com/ethereum/go-ethereum/logger" |
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"github.com/ethereum/go-ethereum/logger/glog" |
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"gopkg.in/fatih/set.v0" |
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) |
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const maxBlockFetch = 256 |
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type hashFetcherFn func(common.Hash) error |
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type blockFetcherFn func([]common.Hash) error |
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type hashCheckFn func(common.Hash) bool |
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type chainInsertFn func(types.Blocks) error |
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type hashIterFn func() (common.Hash, error) |
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// XXX make threadsafe!!!!
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type peers map[string]*peer |
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func (p peers) get(state int) []*peer { |
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var peers []*peer |
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for _, peer := range p { |
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peer.mu.RLock() |
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if peer.state == state { |
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peers = append(peers, peer) |
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} |
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peer.mu.RUnlock() |
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} |
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return peers |
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} |
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func (p peers) setState(id string, state int) { |
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if peer, exist := p[id]; exist { |
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peer.mu.Lock() |
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defer peer.mu.Unlock() |
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peer.state = state |
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} |
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} |
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type Downloader struct { |
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queue *queue |
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hasBlock hashCheckFn |
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insertChain chainInsertFn |
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mu sync.RWMutex |
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peers peers |
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currentPeer *peer |
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fetchingHashes int32 |
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downloadingBlocks int32 |
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newPeerCh chan *peer |
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selectPeerCh chan *peer |
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HashCh chan []common.Hash |
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blockCh chan blockPack |
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quit chan struct{} |
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} |
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type blockPack struct { |
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peerId string |
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blocks []*types.Block |
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} |
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func New(hasBlock hashCheckFn, insertChain chainInsertFn) *Downloader { |
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downloader := &Downloader{ |
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queue: newqueue(), |
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peers: make(peers), |
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hasBlock: hasBlock, |
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insertChain: insertChain, |
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newPeerCh: make(chan *peer, 1), |
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selectPeerCh: make(chan *peer, 1), |
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HashCh: make(chan []common.Hash, 1), |
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blockCh: make(chan blockPack, 1), |
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quit: make(chan struct{}), |
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} |
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go downloader.peerHandler() |
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go downloader.update() |
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return downloader |
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} |
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func (d *Downloader) RegisterPeer(id string, td *big.Int, hash common.Hash, getHashes hashFetcherFn, getBlocks blockFetcherFn) error { |
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d.mu.Lock() |
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defer d.mu.Unlock() |
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glog.V(logger.Detail).Infoln("Register peer", id) |
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// Create a new peer and add it to the list of known peers
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peer := newPeer(id, td, hash, getHashes, getBlocks) |
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// add peer to our peer set
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d.peers[id] = peer |
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// broadcast new peer
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d.newPeerCh <- peer |
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return nil |
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} |
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func (d *Downloader) UnregisterPeer(id string) { |
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d.mu.Lock() |
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defer d.mu.Unlock() |
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glog.V(logger.Detail).Infoln("Unregister peer", id) |
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delete(d.peers, id) |
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} |
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func (d *Downloader) peerHandler() { |
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// Fields defined here so we can reduce the amount of locking
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// that needs to be done
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var highestTd = new(big.Int) |
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out: |
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for { |
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select { |
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case newPeer := <-d.newPeerCh: |
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// Check if TD of peer is higher than our current
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if newPeer.td.Cmp(highestTd) > 0 { |
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glog.V(logger.Detail).Infoln("New peer with highest TD =", newPeer.td) |
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highestTd.Set(newPeer.td) |
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// select the peer for downloading
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d.selectPeerCh <- newPeer |
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} |
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case <-d.quit: |
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break out |
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} |
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} |
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} |
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func (d *Downloader) update() { |
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out: |
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for { |
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select { |
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case selectedPeer := <-d.selectPeerCh: |
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// Make sure it's doing neither. Once done we can restart the
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// downloading process if the TD is higher. For now just get on
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// with whatever is going on. This prevents unecessary switching.
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if !(d.isFetchingHashes() || d.isDownloadingBlocks()) { |
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glog.V(logger.Detail).Infoln("Selected new peer", selectedPeer.id) |
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// Start the fetcher. This will block the update entirely
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// interupts need to be send to the appropriate channels
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// respectively.
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if err := d.startFetchingHashes(selectedPeer); err != nil { |
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// handle error
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glog.V(logger.Debug).Infoln("Error fetching hashes:", err) |
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// Reset
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break |
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} |
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// Start fetching blocks in paralel. The strategy is simple
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// take any available peers, seserve a chunk for each peer available,
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// let the peer deliver the chunkn and periodically check if a peer
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// has timedout. When done downloading, process blocks.
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if err := d.startFetchingBlocks(selectedPeer); err != nil { |
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glog.V(logger.Debug).Infoln("Error downloading blocks:", err) |
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// reset
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break |
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} |
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// XXX this will move when optimised
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// Sort the blocks by number. This bit needs much improvement. Right now
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// it assumes full honesty form peers (i.e. it's not checked when the blocks
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// link). We should at least check whihc queue match. This code could move
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// to a seperate goroutine where it periodically checks for linked pieces.
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types.BlockBy(types.Number).Sort(d.queue.blocks) |
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blocks := d.queue.blocks |
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glog.V(logger.Debug).Infoln("Inserting chain with", len(blocks), "blocks") |
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// Loop untill we're out of queue
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for len(blocks) != 0 { |
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max := int(math.Min(float64(len(blocks)), 256)) |
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// TODO check for parent error. When there's a parent error we should stop
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// processing and start requesting the `block.hash` so that it's parent and
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// grandparents can be requested and queued.
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d.insertChain(blocks[:max]) |
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blocks = blocks[max:] |
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} |
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} |
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case <-d.quit: |
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break out |
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} |
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} |
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} |
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func (d *Downloader) startFetchingHashes(p *peer) error { |
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glog.V(logger.Debug).Infoln("Downloading hashes") |
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start := time.Now() |
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// Get the first batch of hashes
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p.getHashes(p.recentHash) |
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atomic.StoreInt32(&d.fetchingHashes, 1) |
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out: |
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for { |
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select { |
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case hashes := <-d.HashCh: |
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var done bool // determines whether we're done fetching hashes (i.e. common hash found)
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hashSet := set.New() |
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for _, hash := range hashes { |
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if d.hasBlock(hash) { |
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glog.V(logger.Debug).Infof("Found common hash %x\n", hash) |
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done = true |
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break |
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} |
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hashSet.Add(hash) |
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} |
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d.queue.put(hashSet) |
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// Add hashes to the chunk set
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// Check if we're done fetching
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if !done { |
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//fmt.Println("re-fetch. current =", d.queue.hashPool.Size())
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// Get the next set of hashes
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p.getHashes(hashes[len(hashes)-1]) |
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atomic.StoreInt32(&d.fetchingHashes, 1) |
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} else { |
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atomic.StoreInt32(&d.fetchingHashes, 0) |
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break out |
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} |
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} |
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} |
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glog.V(logger.Detail).Infoln("Download hashes: done. Took", time.Since(start)) |
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return nil |
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} |
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func (d *Downloader) DeliverBlocks(id string, block []*types.Block) { |
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d.blockCh <- blockPack{id, block} |
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} |
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func (d *Downloader) startFetchingBlocks(p *peer) error { |
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glog.V(logger.Detail).Infoln("Downloading", d.queue.hashPool.Size(), "blocks") |
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atomic.StoreInt32(&d.downloadingBlocks, 1) |
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start := time.Now() |
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// default ticker for re-fetching blocks everynow and then
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ticker := time.NewTicker(20 * time.Millisecond) |
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out: |
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for { |
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select { |
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case blockPack := <-d.blockCh: |
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//fmt.Println("get for", blockPack.peerId)
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d.queue.deliver(blockPack.peerId, blockPack.blocks) |
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d.peers.setState(blockPack.peerId, idleState) |
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case <-ticker.C: |
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// If there are unrequested hashes left start fetching
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// from the available peers.
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if d.queue.hashPool.Size() > 0 { |
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availablePeers := d.peers.get(idleState) |
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for _, peer := range availablePeers { |
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// Get a possible chunk. If nil is returned no chunk
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// could be returned due to no hashes available.
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chunk := d.queue.get(peer, maxBlockFetch) |
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if chunk != nil { |
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//fmt.Println("fetching for", peer.id)
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// Fetch the chunk.
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peer.fetch(chunk) |
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} |
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} |
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atomic.StoreInt32(&d.downloadingBlocks, 1) |
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} else if len(d.queue.fetching) == 0 { |
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// Whene there are no more queue and no more `fetching`. We can
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// safely assume we're done. Another part of the process will check
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// for parent errors and will re-request anything that's missing
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atomic.StoreInt32(&d.downloadingBlocks, 0) |
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// Break out so that we can process with processing blocks
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break out |
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} else { |
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// Check for bad peers. Bad peers may indicate a peer not responding
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// to a `getBlocks` message. A timeout of 5 seconds is set. Peers
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// that badly or poorly behave are removed from the peer set (not banned).
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// Bad peers are excluded from the available peer set and therefor won't be
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// reused. XXX We could re-introduce peers after X time.
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d.queue.mu.Lock() |
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var badPeers []string |
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for pid, chunk := range d.queue.fetching { |
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if time.Since(chunk.itime) > 5*time.Second { |
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badPeers = append(badPeers, pid) |
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// remove peer as good peer from peer list
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d.UnregisterPeer(pid) |
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} |
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} |
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d.queue.mu.Unlock() |
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for _, pid := range badPeers { |
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// A nil chunk is delivered so that the chunk's hashes are given
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// back to the queue objects. When hashes are put back in the queue
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// other (decent) peers can pick them up.
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// XXX We could make use of a reputation system here ranking peers
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// in their performance
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// 1) Time for them to respond;
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// 2) Measure their speed;
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// 3) Amount and availability.
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d.queue.deliver(pid, nil) |
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} |
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} |
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//fmt.Println(d.queue.hashPool.Size(), len(d.queue.fetching))
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} |
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} |
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glog.V(logger.Detail).Infoln("Download blocks: done. Took", time.Since(start)) |
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return nil |
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} |
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func (d *Downloader) isFetchingHashes() bool { |
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return atomic.LoadInt32(&d.fetchingHashes) == 1 |
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} |
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func (d *Downloader) isDownloadingBlocks() bool { |
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return atomic.LoadInt32(&d.downloadingBlocks) == 1 |
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} |
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@ -0,0 +1,128 @@ |
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package downloader |
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import ( |
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"encoding/binary" |
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"math/big" |
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"testing" |
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"time" |
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"github.com/ethereum/go-ethereum/common" |
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"github.com/ethereum/go-ethereum/core/types" |
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"github.com/ethereum/go-ethereum/logger" |
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"github.com/ethereum/go-ethereum/logger/glog" |
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) |
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var knownHash = common.Hash{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} |
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func createHashes(amount int) (hashes []common.Hash) { |
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hashes = make([]common.Hash, amount+1) |
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hashes[len(hashes)-1] = knownHash |
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for i := range hashes[:len(hashes)-1] { |
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binary.BigEndian.PutUint64(hashes[i][:8], uint64(i+2)) |
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} |
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return |
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} |
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func createBlocksFromHashes(hashes []common.Hash) map[common.Hash]*types.Block { |
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blocks := make(map[common.Hash]*types.Block) |
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for i, hash := range hashes { |
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header := &types.Header{Number: big.NewInt(int64(i))} |
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blocks[hash] = types.NewBlockWithHeader(header) |
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blocks[hash].HeaderHash = hash |
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} |
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return blocks |
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} |
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type downloadTester struct { |
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downloader *Downloader |
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hashes []common.Hash |
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blocks map[common.Hash]*types.Block |
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t *testing.T |
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pcount int |
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done chan bool |
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insertedBlocks int |
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} |
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func newTester(t *testing.T, hashes []common.Hash, blocks map[common.Hash]*types.Block) *downloadTester { |
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tester := &downloadTester{t: t, hashes: hashes, blocks: blocks, done: make(chan bool)} |
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downloader := New(tester.hasBlock, tester.insertChain) |
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tester.downloader = downloader |
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return tester |
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} |
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func (dl *downloadTester) hasBlock(hash common.Hash) bool { |
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if knownHash == hash { |
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return true |
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} |
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return false |
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} |
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func (dl *downloadTester) insertChain(blocks types.Blocks) error { |
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dl.insertedBlocks += len(blocks) |
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if len(dl.blocks)-1 <= dl.insertedBlocks { |
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dl.done <- true |
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} |
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return nil |
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} |
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func (dl *downloadTester) getHashes(hash common.Hash) error { |
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dl.downloader.HashCh <- dl.hashes |
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return nil |
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} |
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func (dl *downloadTester) getBlocks(id string) func([]common.Hash) error { |
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return func(hashes []common.Hash) error { |
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blocks := make([]*types.Block, len(hashes)) |
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for i, hash := range hashes { |
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blocks[i] = dl.blocks[hash] |
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} |
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go dl.downloader.DeliverBlocks(id, blocks) |
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return nil |
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} |
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} |
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func (dl *downloadTester) newPeer(id string, td *big.Int, hash common.Hash) { |
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dl.pcount++ |
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dl.downloader.RegisterPeer(id, td, hash, dl.getHashes, dl.getBlocks(id)) |
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} |
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func (dl *downloadTester) badBlocksPeer(id string, td *big.Int, hash common.Hash) { |
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dl.pcount++ |
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// This bad peer never returns any blocks
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dl.downloader.RegisterPeer(id, td, hash, dl.getHashes, func([]common.Hash) error { |
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return nil |
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}) |
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} |
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func TestDownload(t *testing.T) { |
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glog.SetV(logger.Detail) |
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glog.SetToStderr(true) |
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hashes := createHashes(1000) |
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blocks := createBlocksFromHashes(hashes) |
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tester := newTester(t, hashes, blocks) |
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tester.newPeer("peer1", big.NewInt(10000), hashes[len(hashes)-1]) |
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tester.newPeer("peer2", big.NewInt(0), common.Hash{}) |
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tester.badBlocksPeer("peer3", big.NewInt(0), common.Hash{}) |
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tester.badBlocksPeer("peer4", big.NewInt(0), common.Hash{}) |
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success: |
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select { |
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case <-tester.done: |
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break success |
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case <-time.After(10 * time.Second): // XXX this could actually fail on a slow computer
|
||||
t.Error("timout") |
||||
} |
||||
} |
||||
@ -0,0 +1,48 @@ |
||||
package downloader |
||||
|
||||
import ( |
||||
"math/big" |
||||
"sync" |
||||
|
||||
"github.com/ethereum/go-ethereum/common" |
||||
) |
||||
|
||||
const ( |
||||
workingState = 2 |
||||
idleState = 4 |
||||
) |
||||
|
||||
// peer represents an active peer
|
||||
type peer struct { |
||||
state int |
||||
|
||||
mu sync.RWMutex |
||||
id string |
||||
td *big.Int |
||||
recentHash common.Hash |
||||
|
||||
getHashes hashFetcherFn |
||||
getBlocks blockFetcherFn |
||||
} |
||||
|
||||
// create a new peer
|
||||
func newPeer(id string, td *big.Int, hash common.Hash, getHashes hashFetcherFn, getBlocks blockFetcherFn) *peer { |
||||
return &peer{id: id, td: td, recentHash: hash, getHashes: getHashes, getBlocks: getBlocks, state: idleState} |
||||
} |
||||
|
||||
// fetch a chunk using the peer
|
||||
func (p *peer) fetch(chunk *chunk) { |
||||
p.mu.Lock() |
||||
defer p.mu.Unlock() |
||||
|
||||
// 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 |
||||
}) |
||||
p.getBlocks(hashes) |
||||
} |
||||
Loading…
Reference in new issue