/usr/share/gocode/src/github.com/weaveworks/mesh/gossip_channel.go is in golang-github-weaveworks-mesh-dev 0+git20161024.3dd75b1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | package mesh
import (
"bytes"
"encoding/gob"
"fmt"
)
// gossipChannel is a logical communication channel within a physical mesh.
type gossipChannel struct {
name string
ourself *localPeer
routes *routes
gossiper Gossiper
logger Logger
}
// newGossipChannel returns a named, usable channel.
// It delegates receiving duties to the passed Gossiper.
func newGossipChannel(channelName string, ourself *localPeer, r *routes, g Gossiper, logger Logger) *gossipChannel {
return &gossipChannel{
name: channelName,
ourself: ourself,
routes: r,
gossiper: g,
logger: logger,
}
}
func (c *gossipChannel) deliverUnicast(srcName PeerName, origPayload []byte, dec *gob.Decoder) error {
var destName PeerName
if err := dec.Decode(&destName); err != nil {
return err
}
if c.ourself.Name == destName {
var payload []byte
if err := dec.Decode(&payload); err != nil {
return err
}
return c.gossiper.OnGossipUnicast(srcName, payload)
}
if err := c.relayUnicast(destName, origPayload); err != nil {
c.logf("%v", err)
}
return nil
}
func (c *gossipChannel) deliverBroadcast(srcName PeerName, _ []byte, dec *gob.Decoder) error {
var payload []byte
if err := dec.Decode(&payload); err != nil {
return err
}
data, err := c.gossiper.OnGossipBroadcast(srcName, payload)
if err != nil || data == nil {
return err
}
c.relayBroadcast(srcName, data)
return nil
}
func (c *gossipChannel) deliver(srcName PeerName, _ []byte, dec *gob.Decoder) error {
var payload []byte
if err := dec.Decode(&payload); err != nil {
return err
}
update, err := c.gossiper.OnGossip(payload)
if err != nil || update == nil {
return err
}
c.relay(srcName, update)
return nil
}
// GossipUnicast implements Gossip, relaying msg to dst, which must be a
// member of the channel.
func (c *gossipChannel) GossipUnicast(dstPeerName PeerName, msg []byte) error {
return c.relayUnicast(dstPeerName, gobEncode(c.name, c.ourself.Name, dstPeerName, msg))
}
// GossipBroadcast implements Gossip, relaying update to all members of the
// channel.
func (c *gossipChannel) GossipBroadcast(update GossipData) {
c.relayBroadcast(c.ourself.Name, update)
}
// Send relays data into the channel topology via random neighbours.
func (c *gossipChannel) Send(data GossipData) {
c.relay(c.ourself.Name, data)
}
// SendDown relays data into the channel topology via conn.
func (c *gossipChannel) SendDown(conn Connection, data GossipData) {
c.senderFor(conn).Send(data)
}
func (c *gossipChannel) relayUnicast(dstPeerName PeerName, buf []byte) (err error) {
if relayPeerName, found := c.routes.UnicastAll(dstPeerName); !found {
err = fmt.Errorf("unknown relay destination: %s", dstPeerName)
} else if conn, found := c.ourself.ConnectionTo(relayPeerName); !found {
err = fmt.Errorf("unable to find connection to relay peer %s", relayPeerName)
} else {
err = conn.(protocolSender).SendProtocolMsg(protocolMsg{ProtocolGossipUnicast, buf})
}
return err
}
func (c *gossipChannel) relayBroadcast(srcName PeerName, update GossipData) {
c.routes.ensureRecalculated()
for _, conn := range c.ourself.ConnectionsTo(c.routes.BroadcastAll(srcName)) {
c.senderFor(conn).Broadcast(srcName, update)
}
}
func (c *gossipChannel) relay(srcName PeerName, data GossipData) {
c.routes.ensureRecalculated()
for _, conn := range c.ourself.ConnectionsTo(c.routes.randomNeighbours(srcName)) {
c.senderFor(conn).Send(data)
}
}
func (c *gossipChannel) senderFor(conn Connection) *gossipSender {
return conn.(gossipConnection).gossipSenders().Sender(c.name, c.makeGossipSender)
}
func (c *gossipChannel) makeGossipSender(sender protocolSender, stop <-chan struct{}) *gossipSender {
return newGossipSender(c.makeMsg, c.makeBroadcastMsg, sender, stop)
}
func (c *gossipChannel) makeMsg(msg []byte) protocolMsg {
return protocolMsg{ProtocolGossip, gobEncode(c.name, c.ourself.Name, msg)}
}
func (c *gossipChannel) makeBroadcastMsg(srcName PeerName, msg []byte) protocolMsg {
return protocolMsg{ProtocolGossipBroadcast, gobEncode(c.name, srcName, msg)}
}
func (c *gossipChannel) logf(format string, args ...interface{}) {
format = "[gossip " + c.name + "]: " + format
c.logger.Printf(format, args...)
}
// GobEncode gob-encodes each item and returns the resulting byte slice.
func gobEncode(items ...interface{}) []byte {
buf := new(bytes.Buffer)
enc := gob.NewEncoder(buf)
for _, i := range items {
if err := enc.Encode(i); err != nil {
panic(err)
}
}
return buf.Bytes()
}
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