1490 lines
59 KiB
Go
1490 lines
59 KiB
Go
// Copyright 2015 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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// Package downloader contains the manual full chain synchronisation.
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package downloader
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import (
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"crypto/rand"
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"errors"
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"fmt"
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"math"
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"math/big"
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"strings"
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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/ethdb"
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"github.com/ethereum/go-ethereum/event"
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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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"github.com/ethereum/go-ethereum/params"
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"github.com/ethereum/go-ethereum/trie"
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"github.com/rcrowley/go-metrics"
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)
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var (
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MaxHashFetch = 512 // Amount of hashes to be fetched per retrieval request
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MaxBlockFetch = 128 // Amount of blocks to be fetched per retrieval request
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MaxHeaderFetch = 192 // Amount of block headers to be fetched per retrieval request
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MaxSkeletonSize = 128 // Number of header fetches to need for a skeleton assembly
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MaxBodyFetch = 128 // Amount of block bodies to be fetched per retrieval request
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MaxReceiptFetch = 256 // Amount of transaction receipts to allow fetching per request
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MaxStateFetch = 384 // Amount of node state values to allow fetching per request
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MaxForkAncestry = 3 * params.EpochDuration.Uint64() // Maximum chain reorganisation
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rttMinEstimate = 2 * time.Second // Minimum round-trip time to target for download requests
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rttMaxEstimate = 20 * time.Second // Maximum rount-trip time to target for download requests
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rttMinConfidence = 0.1 // Worse confidence factor in our estimated RTT value
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ttlScaling = 3 // Constant scaling factor for RTT -> TTL conversion
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ttlLimit = time.Minute // Maximum TTL allowance to prevent reaching crazy timeouts
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qosTuningPeers = 5 // Number of peers to tune based on (best peers)
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qosConfidenceCap = 10 // Number of peers above which not to modify RTT confidence
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qosTuningImpact = 0.25 // Impact that a new tuning target has on the previous value
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maxQueuedHeaders = 32 * 1024 // [eth/62] Maximum number of headers to queue for import (DOS protection)
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maxHeadersProcess = 2048 // Number of header download results to import at once into the chain
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maxResultsProcess = 2048 // Number of content download results to import at once into the chain
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fsHeaderCheckFrequency = 100 // Verification frequency of the downloaded headers during fast sync
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fsHeaderSafetyNet = 2048 // Number of headers to discard in case a chain violation is detected
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fsHeaderForceVerify = 24 // Number of headers to verify before and after the pivot to accept it
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fsPivotInterval = 512 // Number of headers out of which to randomize the pivot point
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fsMinFullBlocks = 1024 // Number of blocks to retrieve fully even in fast sync
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fsCriticalTrials = 10 // Number of times to retry in the cricical section before bailing
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)
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var (
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errBusy = errors.New("busy")
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errUnknownPeer = errors.New("peer is unknown or unhealthy")
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errBadPeer = errors.New("action from bad peer ignored")
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errStallingPeer = errors.New("peer is stalling")
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errNoPeers = errors.New("no peers to keep download active")
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errTimeout = errors.New("timeout")
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errEmptyHeaderSet = errors.New("empty header set by peer")
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errPeersUnavailable = errors.New("no peers available or all tried for download")
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errInvalidAncestor = errors.New("retrieved ancestor is invalid")
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errInvalidChain = errors.New("retrieved hash chain is invalid")
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errInvalidBlock = errors.New("retrieved block is invalid")
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errInvalidBody = errors.New("retrieved block body is invalid")
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errInvalidReceipt = errors.New("retrieved receipt is invalid")
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errCancelBlockFetch = errors.New("block download canceled (requested)")
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errCancelHeaderFetch = errors.New("block header download canceled (requested)")
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errCancelBodyFetch = errors.New("block body download canceled (requested)")
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errCancelReceiptFetch = errors.New("receipt download canceled (requested)")
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errCancelStateFetch = errors.New("state data download canceled (requested)")
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errCancelHeaderProcessing = errors.New("header processing canceled (requested)")
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errCancelContentProcessing = errors.New("content processing canceled (requested)")
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errNoSyncActive = errors.New("no sync active")
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errTooOld = errors.New("peer doesn't speak recent enough protocol version (need version >= 62)")
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)
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type Downloader struct {
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mode SyncMode // Synchronisation mode defining the strategy used (per sync cycle)
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mux *event.TypeMux // Event multiplexer to announce sync operation events
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queue *queue // Scheduler for selecting the hashes to download
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peers *peerSet // Set of active peers from which download can proceed
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fsPivotLock *types.Header // Pivot header on critical section entry (cannot change between retries)
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fsPivotFails int // Number of fast sync failures in the critical section
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rttEstimate uint64 // Round trip time to target for download requests
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rttConfidence uint64 // Confidence in the estimated RTT (unit: millionths to allow atomic ops)
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// Statistics
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syncStatsChainOrigin uint64 // Origin block number where syncing started at
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syncStatsChainHeight uint64 // Highest block number known when syncing started
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syncStatsStateDone uint64 // Number of state trie entries already pulled
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syncStatsLock sync.RWMutex // Lock protecting the sync stats fields
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// Callbacks
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hasHeader headerCheckFn // Checks if a header is present in the chain
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hasBlockAndState blockAndStateCheckFn // Checks if a block and associated state is present in the chain
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getHeader headerRetrievalFn // Retrieves a header from the chain
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getBlock blockRetrievalFn // Retrieves a block from the chain
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headHeader headHeaderRetrievalFn // Retrieves the head header from the chain
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headBlock headBlockRetrievalFn // Retrieves the head block from the chain
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headFastBlock headFastBlockRetrievalFn // Retrieves the head fast-sync block from the chain
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commitHeadBlock headBlockCommitterFn // Commits a manually assembled block as the chain head
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getTd tdRetrievalFn // Retrieves the TD of a block from the chain
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insertHeaders headerChainInsertFn // Injects a batch of headers into the chain
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insertBlocks blockChainInsertFn // Injects a batch of blocks into the chain
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insertReceipts receiptChainInsertFn // Injects a batch of blocks and their receipts into the chain
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rollback chainRollbackFn // Removes a batch of recently added chain links
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dropPeer peerDropFn // Drops a peer for misbehaving
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// Status
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synchroniseMock func(id string, hash common.Hash) error // Replacement for synchronise during testing
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synchronising int32
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notified int32
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// Channels
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newPeerCh chan *peer
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headerCh chan dataPack // [eth/62] Channel receiving inbound block headers
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bodyCh chan dataPack // [eth/62] Channel receiving inbound block bodies
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receiptCh chan dataPack // [eth/63] Channel receiving inbound receipts
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stateCh chan dataPack // [eth/63] Channel receiving inbound node state data
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bodyWakeCh chan bool // [eth/62] Channel to signal the block body fetcher of new tasks
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receiptWakeCh chan bool // [eth/63] Channel to signal the receipt fetcher of new tasks
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stateWakeCh chan bool // [eth/63] Channel to signal the state fetcher of new tasks
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headerProcCh chan []*types.Header // [eth/62] Channel to feed the header processor new tasks
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// Cancellation and termination
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cancelPeer string // Identifier of the peer currently being used as the master (cancel on drop)
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cancelCh chan struct{} // Channel to cancel mid-flight syncs
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cancelLock sync.RWMutex // Lock to protect the cancel channel and peer in delivers
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quitCh chan struct{} // Quit channel to signal termination
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quitLock sync.RWMutex // Lock to prevent double closes
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// Testing hooks
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syncInitHook func(uint64, uint64) // Method to call upon initiating a new sync run
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bodyFetchHook func([]*types.Header) // Method to call upon starting a block body fetch
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receiptFetchHook func([]*types.Header) // Method to call upon starting a receipt fetch
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chainInsertHook func([]*fetchResult) // Method to call upon inserting a chain of blocks (possibly in multiple invocations)
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}
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// New creates a new downloader to fetch hashes and blocks from remote peers.
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func New(stateDb ethdb.Database, mux *event.TypeMux, hasHeader headerCheckFn, hasBlockAndState blockAndStateCheckFn,
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getHeader headerRetrievalFn, getBlock blockRetrievalFn, headHeader headHeaderRetrievalFn, headBlock headBlockRetrievalFn,
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headFastBlock headFastBlockRetrievalFn, commitHeadBlock headBlockCommitterFn, getTd tdRetrievalFn, insertHeaders headerChainInsertFn,
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insertBlocks blockChainInsertFn, insertReceipts receiptChainInsertFn, rollback chainRollbackFn, dropPeer peerDropFn) *Downloader {
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dl := &Downloader{
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mode: FullSync,
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mux: mux,
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queue: newQueue(stateDb),
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peers: newPeerSet(),
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rttEstimate: uint64(rttMaxEstimate),
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rttConfidence: uint64(1000000),
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hasHeader: hasHeader,
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hasBlockAndState: hasBlockAndState,
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getHeader: getHeader,
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getBlock: getBlock,
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headHeader: headHeader,
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headBlock: headBlock,
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headFastBlock: headFastBlock,
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commitHeadBlock: commitHeadBlock,
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getTd: getTd,
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insertHeaders: insertHeaders,
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insertBlocks: insertBlocks,
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insertReceipts: insertReceipts,
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rollback: rollback,
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dropPeer: dropPeer,
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newPeerCh: make(chan *peer, 1),
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headerCh: make(chan dataPack, 1),
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bodyCh: make(chan dataPack, 1),
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receiptCh: make(chan dataPack, 1),
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stateCh: make(chan dataPack, 1),
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bodyWakeCh: make(chan bool, 1),
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receiptWakeCh: make(chan bool, 1),
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stateWakeCh: make(chan bool, 1),
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headerProcCh: make(chan []*types.Header, 1),
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quitCh: make(chan struct{}),
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}
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go dl.qosTuner()
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return dl
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}
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// Progress retrieves the synchronisation boundaries, specifically the origin
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// block where synchronisation started at (may have failed/suspended); the block
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// or header sync is currently at; and the latest known block which the sync targets.
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//
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// In addition, during the state download phase of fast synchronisation the number
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// of processed and the total number of known states are also returned. Otherwise
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// these are zero.
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func (d *Downloader) Progress() (uint64, uint64, uint64, uint64, uint64) {
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// Fetch the pending state count outside of the lock to prevent unforeseen deadlocks
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pendingStates := uint64(d.queue.PendingNodeData())
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// Lock the current stats and return the progress
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d.syncStatsLock.RLock()
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defer d.syncStatsLock.RUnlock()
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current := uint64(0)
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switch d.mode {
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case FullSync:
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current = d.headBlock().NumberU64()
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case FastSync:
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current = d.headFastBlock().NumberU64()
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case LightSync:
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current = d.headHeader().Number.Uint64()
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}
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return d.syncStatsChainOrigin, current, d.syncStatsChainHeight, d.syncStatsStateDone, d.syncStatsStateDone + pendingStates
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}
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// Synchronising returns whether the downloader is currently retrieving blocks.
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func (d *Downloader) Synchronising() bool {
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return atomic.LoadInt32(&d.synchronising) > 0
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}
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// RegisterPeer injects a new download peer into the set of block source to be
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// used for fetching hashes and blocks from.
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func (d *Downloader) RegisterPeer(id string, version int, currentHead currentHeadRetrievalFn,
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getRelHeaders relativeHeaderFetcherFn, getAbsHeaders absoluteHeaderFetcherFn, getBlockBodies blockBodyFetcherFn,
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getReceipts receiptFetcherFn, getNodeData stateFetcherFn) error {
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glog.V(logger.Detail).Infoln("Registering peer", id)
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if err := d.peers.Register(newPeer(id, version, currentHead, getRelHeaders, getAbsHeaders, getBlockBodies, getReceipts, getNodeData)); err != nil {
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glog.V(logger.Error).Infoln("Register failed:", err)
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return err
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}
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d.qosReduceConfidence()
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return nil
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}
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// UnregisterPeer remove a peer from the known list, preventing any action from
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// the specified peer. An effort is also made to return any pending fetches into
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// the queue.
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func (d *Downloader) UnregisterPeer(id string) error {
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// Unregister the peer from the active peer set and revoke any fetch tasks
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glog.V(logger.Detail).Infoln("Unregistering peer", id)
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if err := d.peers.Unregister(id); err != nil {
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glog.V(logger.Error).Infoln("Unregister failed:", err)
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return err
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}
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d.queue.Revoke(id)
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// If this peer was the master peer, abort sync immediately
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d.cancelLock.RLock()
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master := id == d.cancelPeer
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d.cancelLock.RUnlock()
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if master {
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d.cancel()
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}
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return nil
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}
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// Synchronise tries to sync up our local block chain with a remote peer, both
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// adding various sanity checks as well as wrapping it with various log entries.
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func (d *Downloader) Synchronise(id string, head common.Hash, td *big.Int, mode SyncMode) error {
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glog.V(logger.Detail).Infof("Attempting synchronisation: %v, head [%x…], TD %v", id, head[:4], td)
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err := d.synchronise(id, head, td, mode)
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switch err {
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case nil:
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glog.V(logger.Detail).Infof("Synchronisation completed")
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case errBusy:
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glog.V(logger.Detail).Infof("Synchronisation already in progress")
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case errTimeout, errBadPeer, errStallingPeer,
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errEmptyHeaderSet, errPeersUnavailable, errTooOld,
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errInvalidAncestor, errInvalidChain:
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glog.V(logger.Debug).Infof("Removing peer %v: %v", id, err)
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d.dropPeer(id)
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default:
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glog.V(logger.Warn).Infof("Synchronisation failed: %v", err)
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}
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return err
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}
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// synchronise will select the peer and use it for synchronising. If an empty string is given
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// it will use the best peer possible and synchronize if it's TD is higher than our own. If any of the
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// checks fail an error will be returned. This method is synchronous
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func (d *Downloader) synchronise(id string, hash common.Hash, td *big.Int, mode SyncMode) error {
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// Mock out the synchronisation if testing
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if d.synchroniseMock != nil {
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return d.synchroniseMock(id, hash)
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}
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// Make sure only one goroutine is ever allowed past this point at once
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if !atomic.CompareAndSwapInt32(&d.synchronising, 0, 1) {
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return errBusy
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}
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defer atomic.StoreInt32(&d.synchronising, 0)
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// Post a user notification of the sync (only once per session)
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if atomic.CompareAndSwapInt32(&d.notified, 0, 1) {
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glog.V(logger.Info).Infoln("Block synchronisation started")
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}
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// Reset the queue, peer set and wake channels to clean any internal leftover state
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d.queue.Reset()
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d.peers.Reset()
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for _, ch := range []chan bool{d.bodyWakeCh, d.receiptWakeCh, d.stateWakeCh} {
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select {
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case <-ch:
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default:
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}
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}
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for _, ch := range []chan dataPack{d.headerCh, d.bodyCh, d.receiptCh, d.stateCh} {
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for empty := false; !empty; {
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select {
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case <-ch:
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default:
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empty = true
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}
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}
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}
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for empty := false; !empty; {
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select {
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case <-d.headerProcCh:
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default:
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empty = true
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}
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}
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// Create cancel channel for aborting mid-flight and mark the master peer
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d.cancelLock.Lock()
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d.cancelCh = make(chan struct{})
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d.cancelPeer = id
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d.cancelLock.Unlock()
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defer d.cancel() // No matter what, we can't leave the cancel channel open
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// Set the requested sync mode, unless it's forbidden
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d.mode = mode
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if d.mode == FastSync && d.fsPivotFails >= fsCriticalTrials {
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d.mode = FullSync
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}
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// Retrieve the origin peer and initiate the downloading process
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p := d.peers.Peer(id)
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if p == nil {
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return errUnknownPeer
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}
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return d.syncWithPeer(p, hash, td)
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}
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// syncWithPeer starts a block synchronization based on the hash chain from the
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// specified peer and head hash.
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func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err error) {
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d.mux.Post(StartEvent{})
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defer func() {
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// reset on error
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if err != nil {
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d.mux.Post(FailedEvent{err})
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} else {
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d.mux.Post(DoneEvent{})
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}
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}()
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if p.version < 62 {
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return errTooOld
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}
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glog.V(logger.Debug).Infof("Synchronising with the network using: %s [eth/%d]", p.id, p.version)
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defer func(start time.Time) {
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glog.V(logger.Debug).Infof("Synchronisation terminated after %v", time.Since(start))
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}(time.Now())
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// Look up the sync boundaries: the common ancestor and the target block
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latest, err := d.fetchHeight(p)
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if err != nil {
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return err
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}
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height := latest.Number.Uint64()
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origin, err := d.findAncestor(p, height)
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if err != nil {
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return err
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}
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d.syncStatsLock.Lock()
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if d.syncStatsChainHeight <= origin || d.syncStatsChainOrigin > origin {
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d.syncStatsChainOrigin = origin
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}
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d.syncStatsChainHeight = height
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d.syncStatsLock.Unlock()
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// Initiate the sync using a concurrent header and content retrieval algorithm
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pivot := uint64(0)
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switch d.mode {
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case LightSync:
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pivot = height
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case FastSync:
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// Calculate the new fast/slow sync pivot point
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if d.fsPivotLock == nil {
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pivotOffset, err := rand.Int(rand.Reader, big.NewInt(int64(fsPivotInterval)))
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if err != nil {
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panic(fmt.Sprintf("Failed to access crypto random source: %v", err))
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}
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if height > uint64(fsMinFullBlocks)+pivotOffset.Uint64() {
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pivot = height - uint64(fsMinFullBlocks) - pivotOffset.Uint64()
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}
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} else {
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// Pivot point locked in, use this and do not pick a new one!
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pivot = d.fsPivotLock.Number.Uint64()
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}
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// If the point is below the origin, move origin back to ensure state download
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if pivot < origin {
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if pivot > 0 {
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origin = pivot - 1
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} else {
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origin = 0
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}
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}
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glog.V(logger.Debug).Infof("Fast syncing until pivot block #%d", pivot)
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}
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d.queue.Prepare(origin+1, d.mode, pivot, latest)
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if d.syncInitHook != nil {
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d.syncInitHook(origin, height)
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}
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return d.spawnSync(origin+1,
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func() error { return d.fetchHeaders(p, origin+1) }, // Headers are always retrieved
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func() error { return d.processHeaders(origin+1, td) }, // Headers are always retrieved
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func() error { return d.fetchBodies(origin + 1) }, // Bodies are retrieved during normal and fast sync
|
|
func() error { return d.fetchReceipts(origin + 1) }, // Receipts are retrieved during fast sync
|
|
func() error { return d.fetchNodeData() }, // Node state data is retrieved during fast sync
|
|
)
|
|
}
|
|
|
|
// spawnSync runs d.process and all given fetcher functions to completion in
|
|
// separate goroutines, returning the first error that appears.
|
|
func (d *Downloader) spawnSync(origin uint64, fetchers ...func() error) error {
|
|
var wg sync.WaitGroup
|
|
errc := make(chan error, len(fetchers)+1)
|
|
wg.Add(len(fetchers) + 1)
|
|
go func() { defer wg.Done(); errc <- d.processContent() }()
|
|
for _, fn := range fetchers {
|
|
fn := fn
|
|
go func() { defer wg.Done(); errc <- fn() }()
|
|
}
|
|
// Wait for the first error, then terminate the others.
|
|
var err error
|
|
for i := 0; i < len(fetchers)+1; i++ {
|
|
if i == len(fetchers) {
|
|
// Close the queue when all fetchers have exited.
|
|
// This will cause the block processor to end when
|
|
// it has processed the queue.
|
|
d.queue.Close()
|
|
}
|
|
if err = <-errc; err != nil {
|
|
break
|
|
}
|
|
}
|
|
d.queue.Close()
|
|
d.cancel()
|
|
wg.Wait()
|
|
return err
|
|
}
|
|
|
|
// cancel cancels all of the operations and resets the queue. It returns true
|
|
// if the cancel operation was completed.
|
|
func (d *Downloader) cancel() {
|
|
// Close the current cancel channel
|
|
d.cancelLock.Lock()
|
|
if d.cancelCh != nil {
|
|
select {
|
|
case <-d.cancelCh:
|
|
// Channel was already closed
|
|
default:
|
|
close(d.cancelCh)
|
|
}
|
|
}
|
|
d.cancelLock.Unlock()
|
|
}
|
|
|
|
// Terminate interrupts the downloader, canceling all pending operations.
|
|
// The downloader cannot be reused after calling Terminate.
|
|
func (d *Downloader) Terminate() {
|
|
// Close the termination channel (make sure double close is allowed)
|
|
d.quitLock.Lock()
|
|
select {
|
|
case <-d.quitCh:
|
|
default:
|
|
close(d.quitCh)
|
|
}
|
|
d.quitLock.Unlock()
|
|
|
|
// Cancel any pending download requests
|
|
d.cancel()
|
|
}
|
|
|
|
// fetchHeight retrieves the head header of the remote peer to aid in estimating
|
|
// the total time a pending synchronisation would take.
|
|
func (d *Downloader) fetchHeight(p *peer) (*types.Header, error) {
|
|
glog.V(logger.Debug).Infof("%v: retrieving remote chain height", p)
|
|
|
|
// Request the advertised remote head block and wait for the response
|
|
head, _ := p.currentHead()
|
|
go p.getRelHeaders(head, 1, 0, false)
|
|
|
|
timeout := time.After(d.requestTTL())
|
|
for {
|
|
select {
|
|
case <-d.cancelCh:
|
|
return nil, errCancelBlockFetch
|
|
|
|
case packet := <-d.headerCh:
|
|
// Discard anything not from the origin peer
|
|
if packet.PeerId() != p.id {
|
|
glog.V(logger.Debug).Infof("Received headers from incorrect peer(%s)", packet.PeerId())
|
|
break
|
|
}
|
|
// Make sure the peer actually gave something valid
|
|
headers := packet.(*headerPack).headers
|
|
if len(headers) != 1 {
|
|
glog.V(logger.Debug).Infof("%v: invalid number of head headers: %d != 1", p, len(headers))
|
|
return nil, errBadPeer
|
|
}
|
|
return headers[0], nil
|
|
|
|
case <-timeout:
|
|
glog.V(logger.Debug).Infof("%v: head header timeout", p)
|
|
return nil, errTimeout
|
|
|
|
case <-d.bodyCh:
|
|
case <-d.stateCh:
|
|
case <-d.receiptCh:
|
|
// Out of bounds delivery, ignore
|
|
}
|
|
}
|
|
}
|
|
|
|
// findAncestor tries to locate the common ancestor link of the local chain and
|
|
// a remote peers blockchain. In the general case when our node was in sync and
|
|
// on the correct chain, checking the top N links should already get us a match.
|
|
// In the rare scenario when we ended up on a long reorganisation (i.e. none of
|
|
// the head links match), we do a binary search to find the common ancestor.
|
|
func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
|
|
glog.V(logger.Debug).Infof("%v: looking for common ancestor (remote height %d)", p, height)
|
|
|
|
// Figure out the valid ancestor range to prevent rewrite attacks
|
|
floor, ceil := int64(-1), d.headHeader().Number.Uint64()
|
|
if d.mode == FullSync {
|
|
ceil = d.headBlock().NumberU64()
|
|
} else if d.mode == FastSync {
|
|
ceil = d.headFastBlock().NumberU64()
|
|
}
|
|
if ceil >= MaxForkAncestry {
|
|
floor = int64(ceil - MaxForkAncestry)
|
|
}
|
|
// Request the topmost blocks to short circuit binary ancestor lookup
|
|
head := ceil
|
|
if head > height {
|
|
head = height
|
|
}
|
|
from := int64(head) - int64(MaxHeaderFetch) + 1
|
|
if from < 0 {
|
|
from = 0
|
|
}
|
|
go p.getAbsHeaders(uint64(from), MaxHeaderFetch, 0, false)
|
|
|
|
// Wait for the remote response to the head fetch
|
|
number, hash := uint64(0), common.Hash{}
|
|
timeout := time.After(d.requestTTL())
|
|
|
|
for finished := false; !finished; {
|
|
select {
|
|
case <-d.cancelCh:
|
|
return 0, errCancelHeaderFetch
|
|
|
|
case packet := <-d.headerCh:
|
|
// Discard anything not from the origin peer
|
|
if packet.PeerId() != p.id {
|
|
glog.V(logger.Debug).Infof("Received headers from incorrect peer(%s)", packet.PeerId())
|
|
break
|
|
}
|
|
// Make sure the peer actually gave something valid
|
|
headers := packet.(*headerPack).headers
|
|
if len(headers) == 0 {
|
|
glog.V(logger.Warn).Infof("%v: empty head header set", p)
|
|
return 0, errEmptyHeaderSet
|
|
}
|
|
// Make sure the peer's reply conforms to the request
|
|
for i := 0; i < len(headers); i++ {
|
|
if number := headers[i].Number.Int64(); number != from+int64(i) {
|
|
glog.V(logger.Warn).Infof("%v: head header set (item %d) broke chain ordering: requested %d, got %d", p, i, from+int64(i), number)
|
|
return 0, errInvalidChain
|
|
}
|
|
if i > 0 && headers[i-1].Hash() != headers[i].ParentHash {
|
|
glog.V(logger.Warn).Infof("%v: head header set (item %d) broke chain ancestry: expected [%x], got [%x]", p, i, headers[i-1].Hash().Bytes()[:4], headers[i].ParentHash[:4])
|
|
return 0, errInvalidChain
|
|
}
|
|
}
|
|
// Check if a common ancestor was found
|
|
finished = true
|
|
for i := len(headers) - 1; i >= 0; i-- {
|
|
// Skip any headers that underflow/overflow our requested set
|
|
if headers[i].Number.Int64() < from || headers[i].Number.Uint64() > head {
|
|
continue
|
|
}
|
|
// Otherwise check if we already know the header or not
|
|
if (d.mode == FullSync && d.hasBlockAndState(headers[i].Hash())) || (d.mode != FullSync && d.hasHeader(headers[i].Hash())) {
|
|
number, hash = headers[i].Number.Uint64(), headers[i].Hash()
|
|
break
|
|
}
|
|
}
|
|
|
|
case <-timeout:
|
|
glog.V(logger.Debug).Infof("%v: head header timeout", p)
|
|
return 0, errTimeout
|
|
|
|
case <-d.bodyCh:
|
|
case <-d.stateCh:
|
|
case <-d.receiptCh:
|
|
// Out of bounds delivery, ignore
|
|
}
|
|
}
|
|
// If the head fetch already found an ancestor, return
|
|
if !common.EmptyHash(hash) {
|
|
if int64(number) <= floor {
|
|
glog.V(logger.Warn).Infof("%v: potential rewrite attack: #%d [%x…] <= #%d limit", p, number, hash[:4], floor)
|
|
return 0, errInvalidAncestor
|
|
}
|
|
glog.V(logger.Debug).Infof("%v: common ancestor: #%d [%x…]", p, number, hash[:4])
|
|
return number, nil
|
|
}
|
|
// Ancestor not found, we need to binary search over our chain
|
|
start, end := uint64(0), head
|
|
if floor > 0 {
|
|
start = uint64(floor)
|
|
}
|
|
for start+1 < end {
|
|
// Split our chain interval in two, and request the hash to cross check
|
|
check := (start + end) / 2
|
|
|
|
timeout := time.After(d.requestTTL())
|
|
go p.getAbsHeaders(uint64(check), 1, 0, false)
|
|
|
|
// Wait until a reply arrives to this request
|
|
for arrived := false; !arrived; {
|
|
select {
|
|
case <-d.cancelCh:
|
|
return 0, errCancelHeaderFetch
|
|
|
|
case packer := <-d.headerCh:
|
|
// Discard anything not from the origin peer
|
|
if packer.PeerId() != p.id {
|
|
glog.V(logger.Debug).Infof("Received headers from incorrect peer(%s)", packer.PeerId())
|
|
break
|
|
}
|
|
// Make sure the peer actually gave something valid
|
|
headers := packer.(*headerPack).headers
|
|
if len(headers) != 1 {
|
|
glog.V(logger.Debug).Infof("%v: invalid search header set (%d)", p, len(headers))
|
|
return 0, errBadPeer
|
|
}
|
|
arrived = true
|
|
|
|
// Modify the search interval based on the response
|
|
if (d.mode == FullSync && !d.hasBlockAndState(headers[0].Hash())) || (d.mode != FullSync && !d.hasHeader(headers[0].Hash())) {
|
|
end = check
|
|
break
|
|
}
|
|
header := d.getHeader(headers[0].Hash()) // Independent of sync mode, header surely exists
|
|
if header.Number.Uint64() != check {
|
|
glog.V(logger.Debug).Infof("%v: non requested header #%d [%x…], instead of #%d", p, header.Number, header.Hash().Bytes()[:4], check)
|
|
return 0, errBadPeer
|
|
}
|
|
start = check
|
|
|
|
case <-timeout:
|
|
glog.V(logger.Debug).Infof("%v: search header timeout", p)
|
|
return 0, errTimeout
|
|
|
|
case <-d.bodyCh:
|
|
case <-d.stateCh:
|
|
case <-d.receiptCh:
|
|
// Out of bounds delivery, ignore
|
|
}
|
|
}
|
|
}
|
|
// Ensure valid ancestry and return
|
|
if int64(start) <= floor {
|
|
glog.V(logger.Warn).Infof("%v: potential rewrite attack: #%d [%x…] <= #%d limit", p, start, hash[:4], floor)
|
|
return 0, errInvalidAncestor
|
|
}
|
|
glog.V(logger.Debug).Infof("%v: common ancestor: #%d [%x…]", p, start, hash[:4])
|
|
return start, nil
|
|
}
|
|
|
|
// fetchHeaders keeps retrieving headers concurrently from the number
|
|
// requested, until no more are returned, potentially throttling on the way. To
|
|
// facilitate concurrency but still protect against malicious nodes sending bad
|
|
// headers, we construct a header chain skeleton using the "origin" peer we are
|
|
// syncing with, and fill in the missing headers using anyone else. Headers from
|
|
// other peers are only accepted if they map cleanly to the skeleton. If no one
|
|
// can fill in the skeleton - not even the origin peer - it's assumed invalid and
|
|
// the origin is dropped.
|
|
func (d *Downloader) fetchHeaders(p *peer, from uint64) error {
|
|
glog.V(logger.Debug).Infof("%v: directing header downloads from #%d", p, from)
|
|
defer glog.V(logger.Debug).Infof("%v: header download terminated", p)
|
|
|
|
// Create a timeout timer, and the associated header fetcher
|
|
skeleton := true // Skeleton assembly phase or finishing up
|
|
request := time.Now() // time of the last skeleton fetch request
|
|
timeout := time.NewTimer(0) // timer to dump a non-responsive active peer
|
|
<-timeout.C // timeout channel should be initially empty
|
|
defer timeout.Stop()
|
|
|
|
getHeaders := func(from uint64) {
|
|
request = time.Now()
|
|
timeout.Reset(d.requestTTL())
|
|
|
|
if skeleton {
|
|
glog.V(logger.Detail).Infof("%v: fetching %d skeleton headers from #%d", p, MaxHeaderFetch, from)
|
|
go p.getAbsHeaders(from+uint64(MaxHeaderFetch)-1, MaxSkeletonSize, MaxHeaderFetch-1, false)
|
|
} else {
|
|
glog.V(logger.Detail).Infof("%v: fetching %d full headers from #%d", p, MaxHeaderFetch, from)
|
|
go p.getAbsHeaders(from, MaxHeaderFetch, 0, false)
|
|
}
|
|
}
|
|
// Start pulling the header chain skeleton until all is done
|
|
getHeaders(from)
|
|
|
|
for {
|
|
select {
|
|
case <-d.cancelCh:
|
|
return errCancelHeaderFetch
|
|
|
|
case packet := <-d.headerCh:
|
|
// Make sure the active peer is giving us the skeleton headers
|
|
if packet.PeerId() != p.id {
|
|
glog.V(logger.Debug).Infof("Received skeleton headers from incorrect peer (%s)", packet.PeerId())
|
|
break
|
|
}
|
|
headerReqTimer.UpdateSince(request)
|
|
timeout.Stop()
|
|
|
|
// If the skeleton's finished, pull any remaining head headers directly from the origin
|
|
if packet.Items() == 0 && skeleton {
|
|
skeleton = false
|
|
getHeaders(from)
|
|
continue
|
|
}
|
|
// If no more headers are inbound, notify the content fetchers and return
|
|
if packet.Items() == 0 {
|
|
glog.V(logger.Debug).Infof("%v: no available headers", p)
|
|
select {
|
|
case d.headerProcCh <- nil:
|
|
return nil
|
|
case <-d.cancelCh:
|
|
return errCancelHeaderFetch
|
|
}
|
|
}
|
|
headers := packet.(*headerPack).headers
|
|
|
|
// If we received a skeleton batch, resolve internals concurrently
|
|
if skeleton {
|
|
filled, proced, err := d.fillHeaderSkeleton(from, headers)
|
|
if err != nil {
|
|
glog.V(logger.Debug).Infof("%v: skeleton chain invalid: %v", p, err)
|
|
return errInvalidChain
|
|
}
|
|
headers = filled[proced:]
|
|
from += uint64(proced)
|
|
}
|
|
// Insert all the new headers and fetch the next batch
|
|
if len(headers) > 0 {
|
|
glog.V(logger.Detail).Infof("%v: schedule %d headers from #%d", p, len(headers), from)
|
|
select {
|
|
case d.headerProcCh <- headers:
|
|
case <-d.cancelCh:
|
|
return errCancelHeaderFetch
|
|
}
|
|
from += uint64(len(headers))
|
|
}
|
|
getHeaders(from)
|
|
|
|
case <-timeout.C:
|
|
// Header retrieval timed out, consider the peer bad and drop
|
|
glog.V(logger.Debug).Infof("%v: header request timed out", p)
|
|
headerTimeoutMeter.Mark(1)
|
|
d.dropPeer(p.id)
|
|
|
|
// Finish the sync gracefully instead of dumping the gathered data though
|
|
for _, ch := range []chan bool{d.bodyWakeCh, d.receiptWakeCh, d.stateWakeCh} {
|
|
select {
|
|
case ch <- false:
|
|
case <-d.cancelCh:
|
|
}
|
|
}
|
|
select {
|
|
case d.headerProcCh <- nil:
|
|
case <-d.cancelCh:
|
|
}
|
|
return errBadPeer
|
|
}
|
|
}
|
|
}
|
|
|
|
// fillHeaderSkeleton concurrently retrieves headers from all our available peers
|
|
// and maps them to the provided skeleton header chain.
|
|
//
|
|
// Any partial results from the beginning of the skeleton is (if possible) forwarded
|
|
// immediately to the header processor to keep the rest of the pipeline full even
|
|
// in the case of header stalls.
|
|
//
|
|
// The method returs the entire filled skeleton and also the number of headers
|
|
// already forwarded for processing.
|
|
func (d *Downloader) fillHeaderSkeleton(from uint64, skeleton []*types.Header) ([]*types.Header, int, error) {
|
|
glog.V(logger.Debug).Infof("Filling up skeleton from #%d", from)
|
|
d.queue.ScheduleSkeleton(from, skeleton)
|
|
|
|
var (
|
|
deliver = func(packet dataPack) (int, error) {
|
|
pack := packet.(*headerPack)
|
|
return d.queue.DeliverHeaders(pack.peerId, pack.headers, d.headerProcCh)
|
|
}
|
|
expire = func() map[string]int { return d.queue.ExpireHeaders(d.requestTTL()) }
|
|
throttle = func() bool { return false }
|
|
reserve = func(p *peer, count int) (*fetchRequest, bool, error) {
|
|
return d.queue.ReserveHeaders(p, count), false, nil
|
|
}
|
|
fetch = func(p *peer, req *fetchRequest) error { return p.FetchHeaders(req.From, MaxHeaderFetch) }
|
|
capacity = func(p *peer) int { return p.HeaderCapacity(d.requestRTT()) }
|
|
setIdle = func(p *peer, accepted int) { p.SetHeadersIdle(accepted) }
|
|
)
|
|
err := d.fetchParts(errCancelHeaderFetch, d.headerCh, deliver, d.queue.headerContCh, expire,
|
|
d.queue.PendingHeaders, d.queue.InFlightHeaders, throttle, reserve,
|
|
nil, fetch, d.queue.CancelHeaders, capacity, d.peers.HeaderIdlePeers, setIdle, "Header")
|
|
|
|
glog.V(logger.Debug).Infof("Skeleton fill terminated: %v", err)
|
|
|
|
filled, proced := d.queue.RetrieveHeaders()
|
|
return filled, proced, err
|
|
}
|
|
|
|
// fetchBodies iteratively downloads the scheduled block bodies, taking any
|
|
// available peers, reserving a chunk of blocks for each, waiting for delivery
|
|
// and also periodically checking for timeouts.
|
|
func (d *Downloader) fetchBodies(from uint64) error {
|
|
glog.V(logger.Debug).Infof("Downloading block bodies from #%d", from)
|
|
|
|
var (
|
|
deliver = func(packet dataPack) (int, error) {
|
|
pack := packet.(*bodyPack)
|
|
return d.queue.DeliverBodies(pack.peerId, pack.transactions, pack.uncles)
|
|
}
|
|
expire = func() map[string]int { return d.queue.ExpireBodies(d.requestTTL()) }
|
|
fetch = func(p *peer, req *fetchRequest) error { return p.FetchBodies(req) }
|
|
capacity = func(p *peer) int { return p.BlockCapacity(d.requestRTT()) }
|
|
setIdle = func(p *peer, accepted int) { p.SetBodiesIdle(accepted) }
|
|
)
|
|
err := d.fetchParts(errCancelBodyFetch, d.bodyCh, deliver, d.bodyWakeCh, expire,
|
|
d.queue.PendingBlocks, d.queue.InFlightBlocks, d.queue.ShouldThrottleBlocks, d.queue.ReserveBodies,
|
|
d.bodyFetchHook, fetch, d.queue.CancelBodies, capacity, d.peers.BodyIdlePeers, setIdle, "Body")
|
|
|
|
glog.V(logger.Debug).Infof("Block body download terminated: %v", err)
|
|
return err
|
|
}
|
|
|
|
// fetchReceipts iteratively downloads the scheduled block receipts, taking any
|
|
// available peers, reserving a chunk of receipts for each, waiting for delivery
|
|
// and also periodically checking for timeouts.
|
|
func (d *Downloader) fetchReceipts(from uint64) error {
|
|
glog.V(logger.Debug).Infof("Downloading receipts from #%d", from)
|
|
|
|
var (
|
|
deliver = func(packet dataPack) (int, error) {
|
|
pack := packet.(*receiptPack)
|
|
return d.queue.DeliverReceipts(pack.peerId, pack.receipts)
|
|
}
|
|
expire = func() map[string]int { return d.queue.ExpireReceipts(d.requestTTL()) }
|
|
fetch = func(p *peer, req *fetchRequest) error { return p.FetchReceipts(req) }
|
|
capacity = func(p *peer) int { return p.ReceiptCapacity(d.requestRTT()) }
|
|
setIdle = func(p *peer, accepted int) { p.SetReceiptsIdle(accepted) }
|
|
)
|
|
err := d.fetchParts(errCancelReceiptFetch, d.receiptCh, deliver, d.receiptWakeCh, expire,
|
|
d.queue.PendingReceipts, d.queue.InFlightReceipts, d.queue.ShouldThrottleReceipts, d.queue.ReserveReceipts,
|
|
d.receiptFetchHook, fetch, d.queue.CancelReceipts, capacity, d.peers.ReceiptIdlePeers, setIdle, "Receipt")
|
|
|
|
glog.V(logger.Debug).Infof("Receipt download terminated: %v", err)
|
|
return err
|
|
}
|
|
|
|
// fetchNodeData iteratively downloads the scheduled state trie nodes, taking any
|
|
// available peers, reserving a chunk of nodes for each, waiting for delivery and
|
|
// also periodically checking for timeouts.
|
|
func (d *Downloader) fetchNodeData() error {
|
|
glog.V(logger.Debug).Infof("Downloading node state data")
|
|
|
|
var (
|
|
deliver = func(packet dataPack) (int, error) {
|
|
start := time.Now()
|
|
return d.queue.DeliverNodeData(packet.PeerId(), packet.(*statePack).states, func(err error, delivered int) {
|
|
// If the peer returned old-requested data, forgive
|
|
if err == trie.ErrNotRequested {
|
|
glog.V(logger.Info).Infof("peer %s: replied to stale state request, forgiving", packet.PeerId())
|
|
return
|
|
}
|
|
if err != nil {
|
|
// If the node data processing failed, the root hash is very wrong, abort
|
|
glog.V(logger.Error).Infof("peer %d: state processing failed: %v", packet.PeerId(), err)
|
|
d.cancel()
|
|
return
|
|
}
|
|
// Processing succeeded, notify state fetcher of continuation
|
|
pending := d.queue.PendingNodeData()
|
|
if pending > 0 {
|
|
select {
|
|
case d.stateWakeCh <- true:
|
|
default:
|
|
}
|
|
}
|
|
d.syncStatsLock.Lock()
|
|
d.syncStatsStateDone += uint64(delivered)
|
|
d.syncStatsLock.Unlock()
|
|
|
|
// Log a message to the user and return
|
|
if delivered > 0 {
|
|
glog.V(logger.Info).Infof("imported %d state entries in %v: processed %d, pending at least %d", delivered, time.Since(start), d.syncStatsStateDone, pending)
|
|
}
|
|
})
|
|
}
|
|
expire = func() map[string]int { return d.queue.ExpireNodeData(d.requestTTL()) }
|
|
throttle = func() bool { return false }
|
|
reserve = func(p *peer, count int) (*fetchRequest, bool, error) {
|
|
return d.queue.ReserveNodeData(p, count), false, nil
|
|
}
|
|
fetch = func(p *peer, req *fetchRequest) error { return p.FetchNodeData(req) }
|
|
capacity = func(p *peer) int { return p.NodeDataCapacity(d.requestRTT()) }
|
|
setIdle = func(p *peer, accepted int) { p.SetNodeDataIdle(accepted) }
|
|
)
|
|
err := d.fetchParts(errCancelStateFetch, d.stateCh, deliver, d.stateWakeCh, expire,
|
|
d.queue.PendingNodeData, d.queue.InFlightNodeData, throttle, reserve, nil, fetch,
|
|
d.queue.CancelNodeData, capacity, d.peers.NodeDataIdlePeers, setIdle, "State")
|
|
|
|
glog.V(logger.Debug).Infof("Node state data download terminated: %v", err)
|
|
return err
|
|
}
|
|
|
|
// fetchParts iteratively downloads scheduled block parts, taking any available
|
|
// peers, reserving a chunk of fetch requests for each, waiting for delivery and
|
|
// also periodically checking for timeouts.
|
|
//
|
|
// As the scheduling/timeout logic mostly is the same for all downloaded data
|
|
// types, this method is used by each for data gathering and is instrumented with
|
|
// various callbacks to handle the slight differences between processing them.
|
|
//
|
|
// The instrumentation parameters:
|
|
// - errCancel: error type to return if the fetch operation is cancelled (mostly makes logging nicer)
|
|
// - deliveryCh: channel from which to retrieve downloaded data packets (merged from all concurrent peers)
|
|
// - deliver: processing callback to deliver data packets into type specific download queues (usually within `queue`)
|
|
// - wakeCh: notification channel for waking the fetcher when new tasks are available (or sync completed)
|
|
// - expire: task callback method to abort requests that took too long and return the faulty peers (traffic shaping)
|
|
// - pending: task callback for the number of requests still needing download (detect completion/non-completability)
|
|
// - inFlight: task callback for the number of in-progress requests (wait for all active downloads to finish)
|
|
// - throttle: task callback to check if the processing queue is full and activate throttling (bound memory use)
|
|
// - reserve: task callback to reserve new download tasks to a particular peer (also signals partial completions)
|
|
// - fetchHook: tester callback to notify of new tasks being initiated (allows testing the scheduling logic)
|
|
// - fetch: network callback to actually send a particular download request to a physical remote peer
|
|
// - cancel: task callback to abort an in-flight download request and allow rescheduling it (in case of lost peer)
|
|
// - capacity: network callback to retreive the estimated type-specific bandwidth capacity of a peer (traffic shaping)
|
|
// - idle: network callback to retrieve the currently (type specific) idle peers that can be assigned tasks
|
|
// - setIdle: network callback to set a peer back to idle and update its estimated capacity (traffic shaping)
|
|
// - kind: textual label of the type being downloaded to display in log mesages
|
|
func (d *Downloader) fetchParts(errCancel error, deliveryCh chan dataPack, deliver func(dataPack) (int, error), wakeCh chan bool,
|
|
expire func() map[string]int, pending func() int, inFlight func() bool, throttle func() bool, reserve func(*peer, int) (*fetchRequest, bool, error),
|
|
fetchHook func([]*types.Header), fetch func(*peer, *fetchRequest) error, cancel func(*fetchRequest), capacity func(*peer) int,
|
|
idle func() ([]*peer, int), setIdle func(*peer, int), kind string) error {
|
|
|
|
// Create a ticker to detect expired retrieval tasks
|
|
ticker := time.NewTicker(100 * time.Millisecond)
|
|
defer ticker.Stop()
|
|
|
|
update := make(chan struct{}, 1)
|
|
|
|
// Prepare the queue and fetch block parts until the block header fetcher's done
|
|
finished := false
|
|
for {
|
|
select {
|
|
case <-d.cancelCh:
|
|
return errCancel
|
|
|
|
case packet := <-deliveryCh:
|
|
// If the peer was previously banned and failed to deliver it's pack
|
|
// in a reasonable time frame, ignore it's message.
|
|
if peer := d.peers.Peer(packet.PeerId()); peer != nil {
|
|
// Deliver the received chunk of data and check chain validity
|
|
accepted, err := deliver(packet)
|
|
if err == errInvalidChain {
|
|
return err
|
|
}
|
|
// Unless a peer delivered something completely else than requested (usually
|
|
// caused by a timed out request which came through in the end), set it to
|
|
// idle. If the delivery's stale, the peer should have already been idled.
|
|
if err != errStaleDelivery {
|
|
setIdle(peer, accepted)
|
|
}
|
|
// Issue a log to the user to see what's going on
|
|
switch {
|
|
case err == nil && packet.Items() == 0:
|
|
glog.V(logger.Detail).Infof("%s: no %s delivered", peer, strings.ToLower(kind))
|
|
case err == nil:
|
|
glog.V(logger.Detail).Infof("%s: delivered %s %s(s)", peer, packet.Stats(), strings.ToLower(kind))
|
|
default:
|
|
glog.V(logger.Detail).Infof("%s: %s delivery failed: %v", peer, strings.ToLower(kind), err)
|
|
}
|
|
}
|
|
// Blocks assembled, try to update the progress
|
|
select {
|
|
case update <- struct{}{}:
|
|
default:
|
|
}
|
|
|
|
case cont := <-wakeCh:
|
|
// The header fetcher sent a continuation flag, check if it's done
|
|
if !cont {
|
|
finished = true
|
|
}
|
|
// Headers arrive, try to update the progress
|
|
select {
|
|
case update <- struct{}{}:
|
|
default:
|
|
}
|
|
|
|
case <-ticker.C:
|
|
// Sanity check update the progress
|
|
select {
|
|
case update <- struct{}{}:
|
|
default:
|
|
}
|
|
|
|
case <-update:
|
|
// Short circuit if we lost all our peers
|
|
if d.peers.Len() == 0 {
|
|
return errNoPeers
|
|
}
|
|
// Check for fetch request timeouts and demote the responsible peers
|
|
for pid, fails := range expire() {
|
|
if peer := d.peers.Peer(pid); peer != nil {
|
|
// If a lot of retrieval elements expired, we might have overestimated the remote peer or perhaps
|
|
// ourselves. Only reset to minimal throughput but don't drop just yet. If even the minimal times
|
|
// out that sync wise we need to get rid of the peer.
|
|
//
|
|
// The reason the minimum threshold is 2 is because the downloader tries to estimate the bandwidth
|
|
// and latency of a peer separately, which requires pushing the measures capacity a bit and seeing
|
|
// how response times reacts, to it always requests one more than the minimum (i.e. min 2).
|
|
if fails > 2 {
|
|
glog.V(logger.Detail).Infof("%s: %s delivery timeout", peer, strings.ToLower(kind))
|
|
setIdle(peer, 0)
|
|
} else {
|
|
glog.V(logger.Debug).Infof("%s: stalling %s delivery, dropping", peer, strings.ToLower(kind))
|
|
d.dropPeer(pid)
|
|
}
|
|
}
|
|
}
|
|
// If there's nothing more to fetch, wait or terminate
|
|
if pending() == 0 {
|
|
if !inFlight() && finished {
|
|
glog.V(logger.Debug).Infof("%s fetching completed", kind)
|
|
return nil
|
|
}
|
|
break
|
|
}
|
|
// Send a download request to all idle peers, until throttled
|
|
progressed, throttled, running := false, false, inFlight()
|
|
idles, total := idle()
|
|
|
|
for _, peer := range idles {
|
|
// Short circuit if throttling activated
|
|
if throttle() {
|
|
throttled = true
|
|
break
|
|
}
|
|
// Reserve a chunk of fetches for a peer. A nil can mean either that
|
|
// no more headers are available, or that the peer is known not to
|
|
// have them.
|
|
request, progress, err := reserve(peer, capacity(peer))
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if progress {
|
|
progressed = true
|
|
}
|
|
if request == nil {
|
|
continue
|
|
}
|
|
if glog.V(logger.Detail) {
|
|
if request.From > 0 {
|
|
glog.Infof("%s: requesting %s(s) from #%d", peer, strings.ToLower(kind), request.From)
|
|
} else if len(request.Headers) > 0 {
|
|
glog.Infof("%s: requesting %d %s(s), first at #%d", peer, len(request.Headers), strings.ToLower(kind), request.Headers[0].Number)
|
|
} else {
|
|
glog.Infof("%s: requesting %d %s(s)", peer, len(request.Hashes), strings.ToLower(kind))
|
|
}
|
|
}
|
|
// Fetch the chunk and make sure any errors return the hashes to the queue
|
|
if fetchHook != nil {
|
|
fetchHook(request.Headers)
|
|
}
|
|
if err := fetch(peer, request); err != nil {
|
|
// Although we could try and make an attempt to fix this, this error really
|
|
// means that we've double allocated a fetch task to a peer. If that is the
|
|
// case, the internal state of the downloader and the queue is very wrong so
|
|
// better hard crash and note the error instead of silently accumulating into
|
|
// a much bigger issue.
|
|
panic(fmt.Sprintf("%v: %s fetch assignment failed", peer, strings.ToLower(kind)))
|
|
}
|
|
running = true
|
|
}
|
|
// Make sure that we have peers available for fetching. If all peers have been tried
|
|
// and all failed throw an error
|
|
if !progressed && !throttled && !running && len(idles) == total && pending() > 0 {
|
|
return errPeersUnavailable
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// processHeaders takes batches of retrieved headers from an input channel and
|
|
// keeps processing and scheduling them into the header chain and downloader's
|
|
// queue until the stream ends or a failure occurs.
|
|
func (d *Downloader) processHeaders(origin uint64, td *big.Int) error {
|
|
// Calculate the pivoting point for switching from fast to slow sync
|
|
pivot := d.queue.FastSyncPivot()
|
|
|
|
// Keep a count of uncertain headers to roll back
|
|
rollback := []*types.Header{}
|
|
defer func() {
|
|
if len(rollback) > 0 {
|
|
// Flatten the headers and roll them back
|
|
hashes := make([]common.Hash, len(rollback))
|
|
for i, header := range rollback {
|
|
hashes[i] = header.Hash()
|
|
}
|
|
lastHeader, lastFastBlock, lastBlock := d.headHeader().Number, d.headFastBlock().Number(), d.headBlock().Number()
|
|
d.rollback(hashes)
|
|
glog.V(logger.Warn).Infof("Rolled back %d headers (LH: %d->%d, FB: %d->%d, LB: %d->%d)",
|
|
len(hashes), lastHeader, d.headHeader().Number, lastFastBlock, d.headFastBlock().Number(), lastBlock, d.headBlock().Number())
|
|
|
|
// If we're already past the pivot point, this could be an attack, thread carefully
|
|
if rollback[len(rollback)-1].Number.Uint64() > pivot {
|
|
// If we didn't ever fail, lock in te pivot header (must! not! change!)
|
|
if d.fsPivotFails == 0 {
|
|
for _, header := range rollback {
|
|
if header.Number.Uint64() == pivot {
|
|
glog.V(logger.Warn).Infof("Fast-sync critical section failure, locked pivot to header #%d [%x…]", pivot, header.Hash().Bytes()[:4])
|
|
d.fsPivotLock = header
|
|
}
|
|
}
|
|
}
|
|
d.fsPivotFails++
|
|
}
|
|
}
|
|
}()
|
|
|
|
// Wait for batches of headers to process
|
|
gotHeaders := false
|
|
|
|
for {
|
|
select {
|
|
case <-d.cancelCh:
|
|
return errCancelHeaderProcessing
|
|
|
|
case headers := <-d.headerProcCh:
|
|
// Terminate header processing if we synced up
|
|
if len(headers) == 0 {
|
|
// Notify everyone that headers are fully processed
|
|
for _, ch := range []chan bool{d.bodyWakeCh, d.receiptWakeCh, d.stateWakeCh} {
|
|
select {
|
|
case ch <- false:
|
|
case <-d.cancelCh:
|
|
}
|
|
}
|
|
// If no headers were retrieved at all, the peer violated it's TD promise that it had a
|
|
// better chain compared to ours. The only exception is if it's promised blocks were
|
|
// already imported by other means (e.g. fecher):
|
|
//
|
|
// R <remote peer>, L <local node>: Both at block 10
|
|
// R: Mine block 11, and propagate it to L
|
|
// L: Queue block 11 for import
|
|
// L: Notice that R's head and TD increased compared to ours, start sync
|
|
// L: Import of block 11 finishes
|
|
// L: Sync begins, and finds common ancestor at 11
|
|
// L: Request new headers up from 11 (R's TD was higher, it must have something)
|
|
// R: Nothing to give
|
|
if !gotHeaders && td.Cmp(d.getTd(d.headBlock().Hash())) > 0 {
|
|
return errStallingPeer
|
|
}
|
|
// If fast or light syncing, ensure promised headers are indeed delivered. This is
|
|
// needed to detect scenarios where an attacker feeds a bad pivot and then bails out
|
|
// of delivering the post-pivot blocks that would flag the invalid content.
|
|
//
|
|
// This check cannot be executed "as is" for full imports, since blocks may still be
|
|
// queued for processing when the header download completes. However, as long as the
|
|
// peer gave us something useful, we're already happy/progressed (above check).
|
|
if d.mode == FastSync || d.mode == LightSync {
|
|
if td.Cmp(d.getTd(d.headHeader().Hash())) > 0 {
|
|
return errStallingPeer
|
|
}
|
|
}
|
|
// Disable any rollback and return
|
|
rollback = nil
|
|
return nil
|
|
}
|
|
// Otherwise split the chunk of headers into batches and process them
|
|
gotHeaders = true
|
|
|
|
for len(headers) > 0 {
|
|
// Terminate if something failed in between processing chunks
|
|
select {
|
|
case <-d.cancelCh:
|
|
return errCancelHeaderProcessing
|
|
default:
|
|
}
|
|
// Select the next chunk of headers to import
|
|
limit := maxHeadersProcess
|
|
if limit > len(headers) {
|
|
limit = len(headers)
|
|
}
|
|
chunk := headers[:limit]
|
|
|
|
// In case of header only syncing, validate the chunk immediately
|
|
if d.mode == FastSync || d.mode == LightSync {
|
|
// Collect the yet unknown headers to mark them as uncertain
|
|
unknown := make([]*types.Header, 0, len(headers))
|
|
for _, header := range chunk {
|
|
if !d.hasHeader(header.Hash()) {
|
|
unknown = append(unknown, header)
|
|
}
|
|
}
|
|
// If we're importing pure headers, verify based on their recentness
|
|
frequency := fsHeaderCheckFrequency
|
|
if chunk[len(chunk)-1].Number.Uint64()+uint64(fsHeaderForceVerify) > pivot {
|
|
frequency = 1
|
|
}
|
|
if n, err := d.insertHeaders(chunk, frequency); err != nil {
|
|
// If some headers were inserted, add them too to the rollback list
|
|
if n > 0 {
|
|
rollback = append(rollback, chunk[:n]...)
|
|
}
|
|
glog.V(logger.Debug).Infof("invalid header #%d [%x…]: %v", chunk[n].Number, chunk[n].Hash().Bytes()[:4], err)
|
|
return errInvalidChain
|
|
}
|
|
// All verifications passed, store newly found uncertain headers
|
|
rollback = append(rollback, unknown...)
|
|
if len(rollback) > fsHeaderSafetyNet {
|
|
rollback = append(rollback[:0], rollback[len(rollback)-fsHeaderSafetyNet:]...)
|
|
}
|
|
}
|
|
// If we're fast syncing and just pulled in the pivot, make sure it's the one locked in
|
|
if d.mode == FastSync && d.fsPivotLock != nil && chunk[0].Number.Uint64() <= pivot && chunk[len(chunk)-1].Number.Uint64() >= pivot {
|
|
if pivot := chunk[int(pivot-chunk[0].Number.Uint64())]; pivot.Hash() != d.fsPivotLock.Hash() {
|
|
glog.V(logger.Warn).Infof("Pivot doesn't match locked in version: have #%v [%x…], want #%v [%x…]", pivot.Number, pivot.Hash().Bytes()[:4], d.fsPivotLock.Number, d.fsPivotLock.Hash().Bytes()[:4])
|
|
return errInvalidChain
|
|
}
|
|
}
|
|
// Unless we're doing light chains, schedule the headers for associated content retrieval
|
|
if d.mode == FullSync || d.mode == FastSync {
|
|
// If we've reached the allowed number of pending headers, stall a bit
|
|
for d.queue.PendingBlocks() >= maxQueuedHeaders || d.queue.PendingReceipts() >= maxQueuedHeaders {
|
|
select {
|
|
case <-d.cancelCh:
|
|
return errCancelHeaderProcessing
|
|
case <-time.After(time.Second):
|
|
}
|
|
}
|
|
// Otherwise insert the headers for content retrieval
|
|
inserts := d.queue.Schedule(chunk, origin)
|
|
if len(inserts) != len(chunk) {
|
|
glog.V(logger.Debug).Infof("stale headers")
|
|
return errBadPeer
|
|
}
|
|
}
|
|
headers = headers[limit:]
|
|
origin += uint64(limit)
|
|
}
|
|
// Signal the content downloaders of the availablility of new tasks
|
|
for _, ch := range []chan bool{d.bodyWakeCh, d.receiptWakeCh, d.stateWakeCh} {
|
|
select {
|
|
case ch <- true:
|
|
default:
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// processContent takes fetch results from the queue and tries to import them
|
|
// into the chain. The type of import operation will depend on the result contents.
|
|
func (d *Downloader) processContent() error {
|
|
pivot := d.queue.FastSyncPivot()
|
|
for {
|
|
results := d.queue.WaitResults()
|
|
if len(results) == 0 {
|
|
return nil // queue empty
|
|
}
|
|
if d.chainInsertHook != nil {
|
|
d.chainInsertHook(results)
|
|
}
|
|
// Actually import the blocks
|
|
if glog.V(logger.Debug) {
|
|
first, last := results[0].Header, results[len(results)-1].Header
|
|
glog.Infof("Inserting chain with %d items (#%d [%x…] - #%d [%x…])", len(results), first.Number, first.Hash().Bytes()[:4], last.Number, last.Hash().Bytes()[:4])
|
|
}
|
|
for len(results) != 0 {
|
|
// Check for any termination requests
|
|
select {
|
|
case <-d.quitCh:
|
|
return errCancelContentProcessing
|
|
default:
|
|
}
|
|
// Retrieve the a batch of results to import
|
|
var (
|
|
blocks = make([]*types.Block, 0, maxResultsProcess)
|
|
receipts = make([]types.Receipts, 0, maxResultsProcess)
|
|
)
|
|
items := int(math.Min(float64(len(results)), float64(maxResultsProcess)))
|
|
for _, result := range results[:items] {
|
|
switch {
|
|
case d.mode == FullSync:
|
|
blocks = append(blocks, types.NewBlockWithHeader(result.Header).WithBody(result.Transactions, result.Uncles))
|
|
case d.mode == FastSync:
|
|
blocks = append(blocks, types.NewBlockWithHeader(result.Header).WithBody(result.Transactions, result.Uncles))
|
|
if result.Header.Number.Uint64() <= pivot {
|
|
receipts = append(receipts, result.Receipts)
|
|
}
|
|
}
|
|
}
|
|
// Try to process the results, aborting if there's an error
|
|
var (
|
|
err error
|
|
index int
|
|
)
|
|
switch {
|
|
case len(receipts) > 0:
|
|
index, err = d.insertReceipts(blocks, receipts)
|
|
if err == nil && blocks[len(blocks)-1].NumberU64() == pivot {
|
|
glog.V(logger.Debug).Infof("Committing block #%d [%x…] as the new head", blocks[len(blocks)-1].Number(), blocks[len(blocks)-1].Hash().Bytes()[:4])
|
|
index, err = len(blocks)-1, d.commitHeadBlock(blocks[len(blocks)-1].Hash())
|
|
}
|
|
default:
|
|
index, err = d.insertBlocks(blocks)
|
|
}
|
|
if err != nil {
|
|
glog.V(logger.Debug).Infof("Result #%d [%x…] processing failed: %v", results[index].Header.Number, results[index].Header.Hash().Bytes()[:4], err)
|
|
return errInvalidChain
|
|
}
|
|
// Shift the results to the next batch
|
|
results = results[items:]
|
|
}
|
|
}
|
|
}
|
|
|
|
// DeliverHeaders injects a new batch of block headers received from a remote
|
|
// node into the download schedule.
|
|
func (d *Downloader) DeliverHeaders(id string, headers []*types.Header) (err error) {
|
|
return d.deliver(id, d.headerCh, &headerPack{id, headers}, headerInMeter, headerDropMeter)
|
|
}
|
|
|
|
// DeliverBodies injects a new batch of block bodies received from a remote node.
|
|
func (d *Downloader) DeliverBodies(id string, transactions [][]*types.Transaction, uncles [][]*types.Header) (err error) {
|
|
return d.deliver(id, d.bodyCh, &bodyPack{id, transactions, uncles}, bodyInMeter, bodyDropMeter)
|
|
}
|
|
|
|
// DeliverReceipts injects a new batch of receipts received from a remote node.
|
|
func (d *Downloader) DeliverReceipts(id string, receipts [][]*types.Receipt) (err error) {
|
|
return d.deliver(id, d.receiptCh, &receiptPack{id, receipts}, receiptInMeter, receiptDropMeter)
|
|
}
|
|
|
|
// DeliverNodeData injects a new batch of node state data received from a remote node.
|
|
func (d *Downloader) DeliverNodeData(id string, data [][]byte) (err error) {
|
|
return d.deliver(id, d.stateCh, &statePack{id, data}, stateInMeter, stateDropMeter)
|
|
}
|
|
|
|
// deliver injects a new batch of data received from a remote node.
|
|
func (d *Downloader) deliver(id string, destCh chan dataPack, packet dataPack, inMeter, dropMeter metrics.Meter) (err error) {
|
|
// Update the delivery metrics for both good and failed deliveries
|
|
inMeter.Mark(int64(packet.Items()))
|
|
defer func() {
|
|
if err != nil {
|
|
dropMeter.Mark(int64(packet.Items()))
|
|
}
|
|
}()
|
|
// Deliver or abort if the sync is canceled while queuing
|
|
d.cancelLock.RLock()
|
|
cancel := d.cancelCh
|
|
d.cancelLock.RUnlock()
|
|
if cancel == nil {
|
|
return errNoSyncActive
|
|
}
|
|
select {
|
|
case destCh <- packet:
|
|
return nil
|
|
case <-cancel:
|
|
return errNoSyncActive
|
|
}
|
|
}
|
|
|
|
// qosTuner is the quality of service tuning loop that occasionally gathers the
|
|
// peer latency statistics and updates the estimated request round trip time.
|
|
func (d *Downloader) qosTuner() {
|
|
for {
|
|
// Retrieve the current median RTT and integrate into the previoust target RTT
|
|
rtt := time.Duration(float64(1-qosTuningImpact)*float64(atomic.LoadUint64(&d.rttEstimate)) + qosTuningImpact*float64(d.peers.medianRTT()))
|
|
atomic.StoreUint64(&d.rttEstimate, uint64(rtt))
|
|
|
|
// A new RTT cycle passed, increase our confidence in the estimated RTT
|
|
conf := atomic.LoadUint64(&d.rttConfidence)
|
|
conf = conf + (1000000-conf)/2
|
|
atomic.StoreUint64(&d.rttConfidence, conf)
|
|
|
|
// Log the new QoS values and sleep until the next RTT
|
|
glog.V(logger.Debug).Infof("Quality of service: rtt %v, conf %.3f, ttl %v", rtt, float64(conf)/1000000.0, d.requestTTL())
|
|
select {
|
|
case <-d.quitCh:
|
|
return
|
|
case <-time.After(rtt):
|
|
}
|
|
}
|
|
}
|
|
|
|
// qosReduceConfidence is meant to be called when a new peer joins the downloader's
|
|
// peer set, needing to reduce the confidence we have in out QoS estimates.
|
|
func (d *Downloader) qosReduceConfidence() {
|
|
// If we have a single peer, confidence is always 1
|
|
peers := uint64(d.peers.Len())
|
|
if peers == 1 {
|
|
atomic.StoreUint64(&d.rttConfidence, 1000000)
|
|
return
|
|
}
|
|
// If we have a ton of peers, don't drop confidence)
|
|
if peers >= uint64(qosConfidenceCap) {
|
|
return
|
|
}
|
|
// Otherwise drop the confidence factor
|
|
conf := atomic.LoadUint64(&d.rttConfidence) * (peers - 1) / peers
|
|
if float64(conf)/1000000 < rttMinConfidence {
|
|
conf = uint64(rttMinConfidence * 1000000)
|
|
}
|
|
atomic.StoreUint64(&d.rttConfidence, conf)
|
|
|
|
rtt := time.Duration(atomic.LoadUint64(&d.rttEstimate))
|
|
glog.V(logger.Debug).Infof("Quality of service: rtt %v, conf %.3f, ttl %v", rtt, float64(conf)/1000000.0, d.requestTTL())
|
|
}
|
|
|
|
// requestRTT returns the current target round trip time for a download request
|
|
// to complete in.
|
|
//
|
|
// Note, the returned RTT is .9 of the actually estimated RTT. The reason is that
|
|
// the downloader tries to adapt queries to the RTT, so multiple RTT values can
|
|
// be adapted to, but smaller ones are preffered (stabler download stream).
|
|
func (d *Downloader) requestRTT() time.Duration {
|
|
return time.Duration(atomic.LoadUint64(&d.rttEstimate)) * 9 / 10
|
|
}
|
|
|
|
// requestTTL returns the current timeout allowance for a single download request
|
|
// to finish under.
|
|
func (d *Downloader) requestTTL() time.Duration {
|
|
var (
|
|
rtt = time.Duration(atomic.LoadUint64(&d.rttEstimate))
|
|
conf = float64(atomic.LoadUint64(&d.rttConfidence)) / 1000000.0
|
|
)
|
|
ttl := time.Duration(ttlScaling) * time.Duration(float64(rtt)/conf)
|
|
if ttl > ttlLimit {
|
|
ttl = ttlLimit
|
|
}
|
|
return ttl
|
|
}
|