/usr/share/gocode/src/github.com/coreos/go-etcd/etcd/watch.go is in golang-github-coreos-go-etcd-dev 2.0.0-4.
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 | package etcd
import (
"errors"
)
// Errors introduced by the Watch command.
var (
ErrWatchStoppedByUser = errors.New("Watch stopped by the user via stop channel")
)
// If recursive is set to true the watch returns the first change under the given
// prefix since the given index.
//
// If recursive is set to false the watch returns the first change to the given key
// since the given index.
//
// To watch for the latest change, set waitIndex = 0.
//
// If a receiver channel is given, it will be a long-term watch. Watch will block at the
//channel. After someone receives the channel, it will go on to watch that
// prefix. If a stop channel is given, the client can close long-term watch using
// the stop channel.
func (c *Client) Watch(prefix string, waitIndex uint64, recursive bool,
receiver chan *Response, stop chan bool) (*Response, error) {
logger.Debugf("watch %s [%s]", prefix, c.cluster.Leader)
if receiver == nil {
raw, err := c.watchOnce(prefix, waitIndex, recursive, stop)
if err != nil {
return nil, err
}
return raw.Unmarshal()
}
defer close(receiver)
for {
raw, err := c.watchOnce(prefix, waitIndex, recursive, stop)
if err != nil {
return nil, err
}
resp, err := raw.Unmarshal()
if err != nil {
return nil, err
}
waitIndex = resp.Node.ModifiedIndex + 1
receiver <- resp
}
}
func (c *Client) RawWatch(prefix string, waitIndex uint64, recursive bool,
receiver chan *RawResponse, stop chan bool) (*RawResponse, error) {
logger.Debugf("rawWatch %s [%s]", prefix, c.cluster.Leader)
if receiver == nil {
return c.watchOnce(prefix, waitIndex, recursive, stop)
}
for {
raw, err := c.watchOnce(prefix, waitIndex, recursive, stop)
if err != nil {
return nil, err
}
resp, err := raw.Unmarshal()
if err != nil {
return nil, err
}
waitIndex = resp.Node.ModifiedIndex + 1
receiver <- raw
}
}
// helper func
// return when there is change under the given prefix
func (c *Client) watchOnce(key string, waitIndex uint64, recursive bool, stop chan bool) (*RawResponse, error) {
options := Options{
"wait": true,
}
if waitIndex > 0 {
options["waitIndex"] = waitIndex
}
if recursive {
options["recursive"] = true
}
resp, err := c.getCancelable(key, options, stop)
if err == ErrRequestCancelled {
return nil, ErrWatchStoppedByUser
}
return resp, err
}
|