134 lines
2.8 KiB
Go
134 lines
2.8 KiB
Go
package store
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import (
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"path"
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"strconv"
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"strings"
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)
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//------------------------------------------------------------------------------
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//
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// Typedefs
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//
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//------------------------------------------------------------------------------
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// WatcherHub is where the client register its watcher
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type WatcherHub struct {
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watchers map[string][]*Watcher
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}
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// Currently watcher only contains a response channel
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type Watcher struct {
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C chan *Response
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}
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// Create a new watcherHub
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func newWatcherHub() *WatcherHub {
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w := new(WatcherHub)
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w.watchers = make(map[string][]*Watcher)
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return w
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}
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// Create a new watcher
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func NewWatcher() *Watcher {
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return &Watcher{C: make(chan *Response, 1)}
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}
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// Add a watcher to the watcherHub
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func (w *WatcherHub) addWatcher(prefix string, watcher *Watcher, sinceIndex uint64,
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responseStartIndex uint64, currentIndex uint64, resMap *map[string]*Response) error {
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prefix = path.Clean("/" + prefix)
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if sinceIndex != 0 && sinceIndex >= responseStartIndex {
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for i := sinceIndex; i <= currentIndex; i++ {
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if checkResponse(prefix, i, resMap) {
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watcher.C <- (*resMap)[strconv.FormatUint(i, 10)]
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return nil
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}
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}
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}
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_, ok := w.watchers[prefix]
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if !ok {
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w.watchers[prefix] = make([]*Watcher, 0)
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w.watchers[prefix] = append(w.watchers[prefix], watcher)
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} else {
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w.watchers[prefix] = append(w.watchers[prefix], watcher)
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}
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return nil
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}
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// Check if the response has what we are watching
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func checkResponse(prefix string, index uint64, resMap *map[string]*Response) bool {
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resp, ok := (*resMap)[strconv.FormatUint(index, 10)]
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if !ok {
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// not storage system command
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return false
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} else {
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path := resp.Key
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if strings.HasPrefix(path, prefix) {
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prefixLen := len(prefix)
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if len(path) == prefixLen || path[prefixLen] == '/' {
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return true
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}
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}
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}
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return false
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}
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// Notify the watcher a action happened
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func (w *WatcherHub) notify(resp Response) error {
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resp.Key = path.Clean(resp.Key)
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segments := strings.Split(resp.Key, "/")
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currPath := "/"
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// walk through all the pathes
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for _, segment := range segments {
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currPath = path.Join(currPath, segment)
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watchers, ok := w.watchers[currPath]
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if ok {
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newWatchers := make([]*Watcher, 0)
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// notify all the watchers
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for _, watcher := range watchers {
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watcher.C <- &resp
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}
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if len(newWatchers) == 0 {
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// we have notified all the watchers at this path
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// delete the map
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delete(w.watchers, currPath)
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} else {
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w.watchers[currPath] = newWatchers
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}
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}
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}
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return nil
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}
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// stopWatchers stops all the watchers
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// This function is used when the etcd recovery from a snapshot at runtime
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func (w *WatcherHub) stopWatchers() {
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for _, subWatchers := range w.watchers {
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for _, watcher := range subWatchers {
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watcher.C <- nil
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}
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}
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w.watchers = nil
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}
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