aboutsummaryrefslogtreecommitdiffstats
path: root/eth/sync.go
blob: 1a1cbdb47b37856cc9f611a0d0f1ae284cff63ae (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
package eth

import (
    "math"
    "sync/atomic"
    "time"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/eth/downloader"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
)

// blockAnnounce is the hash notification of the availability of a new block in
// the network.
type blockAnnounce struct {
    hash common.Hash
    peer *peer
    time time.Time
}

// fetcher is responsible for collecting hash notifications, and periodically
// checking all unknown ones and individually fetching them.
func (pm *ProtocolManager) fetcher() {
    announces := make(map[common.Hash]*blockAnnounce)
    request := make(map[*peer][]common.Hash)
    cycle := time.Tick(notifyCheckCycle)

    // Iterate the block fetching until a quit is requested
    for {
        select {
        case notifications := <-pm.newHashCh:
            // A batch of hashes the notified, schedule them for retrieval
            glog.V(logger.Detail).Infof("Scheduling %d hash announces from %s", len(notifications), notifications[0].peer.id)
            for _, announce := range notifications {
                announces[announce.hash] = announce
            }

        case <-cycle:
            // Check if any notified blocks failed to arrive
            for hash, announce := range announces {
                if time.Since(announce.time) > notifyArriveTimeout {
                    if !pm.chainman.HasBlock(hash) {
                        request[announce.peer] = append(request[announce.peer], hash)
                    }
                    delete(announces, hash)
                }
            }
            if len(request) == 0 {
                break
            }
            // Send out all block requests
            for peer, hashes := range request {
                glog.V(logger.Detail).Infof("Fetching specific %d blocks from %s", len(hashes), peer.id)
                peer.requestBlocks(hashes)
            }
            request = make(map[*peer][]common.Hash)

        case <-pm.quitSync:
            return
        }
    }
}

// syncer is responsible for periodically synchronising with the network, both
// downloading hashes and blocks as well as retrieving cached ones.
func (pm *ProtocolManager) syncer() {
    forceSync := time.Tick(forceSyncCycle)
    blockProc := time.Tick(blockProcCycle)
    blockProcPend := int32(0)

    for {
        select {
        case <-pm.newPeerCh:
            // Make sure we have peers to select from, then sync
            if pm.peers.Len() < minDesiredPeerCount {
                break
            }
            go pm.synchronise(pm.peers.BestPeer())

        case <-forceSync:
            // Force a sync even if not enough peers are present
            go pm.synchronise(pm.peers.BestPeer())

        case <-blockProc:
            // Try to pull some blocks from the downloaded
            if atomic.CompareAndSwapInt32(&blockProcPend, 0, 1) {
                go func() {
                    pm.processBlocks()
                    atomic.StoreInt32(&blockProcPend, 0)
                }()
            }

        case <-pm.quitSync:
            return
        }
    }
}

// processBlocks retrieves downloaded blocks from the download cache and tries
// to construct the local block chain with it. Note, since the block retrieval
// order matters, access to this function *must* be synchronized/serialized.
func (pm *ProtocolManager) processBlocks() error {
    pm.wg.Add(1)
    defer pm.wg.Done()

    // Short circuit if no blocks are available for insertion
    blocks := pm.downloader.TakeBlocks()
    if len(blocks) == 0 {
        return nil
    }
    glog.V(logger.Debug).Infof("Inserting chain with %d blocks (#%v - #%v)\n", len(blocks), blocks[0].RawBlock.Number(), blocks[len(blocks)-1].RawBlock.Number())

    for len(blocks) != 0 && !pm.quit {
        // Retrieve the first batch of blocks to insert
        max := int(math.Min(float64(len(blocks)), float64(blockProcAmount)))
        raw := make(types.Blocks, 0, max)
        for _, block := range blocks[:max] {
            raw = append(raw, block.RawBlock)
        }
        // Try to inset the blocks, drop the originating peer if there's an error
        index, err := pm.chainman.InsertChain(raw)
        if err != nil {
            glog.V(logger.Debug).Infoln("Downloaded block import failed:", err)
            pm.removePeer(blocks[index].OriginPeer)
            pm.downloader.Cancel()
            return err
        }
        blocks = blocks[max:]
    }
    return nil
}

// synchronise tries to sync up our local block chain with a remote peer, both
// adding various sanity checks as well as wrapping it with various log entries.
func (pm *ProtocolManager) synchronise(peer *peer) {
    // Short circuit if no peers are available
    if peer == nil {
        return
    }
    // Make sure the peer's TD is higher than our own. If not drop.
    if peer.td.Cmp(pm.chainman.Td()) <= 0 {
        return
    }
    // FIXME if we have the hash in our chain and the TD of the peer is
    // much higher than ours, something is wrong with us or the peer.
    // Check if the hash is on our own chain
    if pm.chainman.HasBlock(peer.recentHash) {
        glog.V(logger.Debug).Infoln("Synchronisation canceled: head already known")
        return
    }
    // Get the hashes from the peer (synchronously)
    glog.V(logger.Debug).Infof("Attempting synchronisation: %v, 0x%x", peer.id, peer.recentHash)

    err := pm.downloader.Synchronise(peer.id, peer.recentHash)
    switch err {
    case nil:
        glog.V(logger.Debug).Infof("Synchronisation completed")

    case downloader.ErrBusy:
        glog.V(logger.Debug).Infof("Synchronisation already in progress")

    case downloader.ErrTimeout, downloader.ErrBadPeer, downloader.ErrEmptyHashSet, downloader.ErrInvalidChain, downloader.ErrCrossCheckFailed:
        glog.V(logger.Debug).Infof("Removing peer %v: %v", peer.id, err)
        pm.removePeer(peer.id)

    case downloader.ErrPendingQueue:
        glog.V(logger.Debug).Infoln("Synchronisation aborted:", err)

    default:
        glog.V(logger.Warn).Infof("Synchronisation failed: %v", err)
    }
}