diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/rjeczalik/notify/tree_nonrecursive.go')
-rw-r--r-- | Godeps/_workspace/src/github.com/rjeczalik/notify/tree_nonrecursive.go | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/rjeczalik/notify/tree_nonrecursive.go b/Godeps/_workspace/src/github.com/rjeczalik/notify/tree_nonrecursive.go new file mode 100644 index 000000000..dfa72d1d2 --- /dev/null +++ b/Godeps/_workspace/src/github.com/rjeczalik/notify/tree_nonrecursive.go @@ -0,0 +1,292 @@ +// Copyright (c) 2014-2015 The Notify Authors. All rights reserved. +// Use of this source code is governed by the MIT license that can be +// found in the LICENSE file. + +package notify + +import "sync" + +// nonrecursiveTree TODO(rjeczalik) +type nonrecursiveTree struct { + rw sync.RWMutex // protects root + root root + w watcher + c chan EventInfo + rec chan EventInfo +} + +// newNonrecursiveTree TODO(rjeczalik) +func newNonrecursiveTree(w watcher, c, rec chan EventInfo) *nonrecursiveTree { + if rec == nil { + rec = make(chan EventInfo, buffer) + } + t := &nonrecursiveTree{ + root: root{nd: newnode("")}, + w: w, + c: c, + rec: rec, + } + go t.dispatch(c) + go t.internal(rec) + return t +} + +// dispatch TODO(rjeczalik) +func (t *nonrecursiveTree) dispatch(c <-chan EventInfo) { + for ei := range c { + dbgprintf("dispatching %v on %q", ei.Event(), ei.Path()) + go func(ei EventInfo) { + var nd node + var isrec bool + dir, base := split(ei.Path()) + fn := func(it node, isbase bool) error { + isrec = isrec || it.Watch.IsRecursive() + if isbase { + nd = it + } else { + it.Watch.Dispatch(ei, recursive) + } + return nil + } + t.rw.RLock() + // Notify recursive watchpoints found on the path. + if err := t.root.WalkPath(dir, fn); err != nil { + dbgprint("dispatch did not reach leaf:", err) + t.rw.RUnlock() + return + } + // Notify parent watchpoint. + nd.Watch.Dispatch(ei, 0) + isrec = isrec || nd.Watch.IsRecursive() + // If leaf watchpoint exists, notify it. + if nd, ok := nd.Child[base]; ok { + isrec = isrec || nd.Watch.IsRecursive() + nd.Watch.Dispatch(ei, 0) + } + t.rw.RUnlock() + // If the event describes newly leaf directory created within + if !isrec || ei.Event() != Create { + return + } + if ok, err := ei.(isDirer).isDir(); !ok || err != nil { + return + } + t.rec <- ei + }(ei) + } +} + +// internal TODO(rjeczalik) +func (t *nonrecursiveTree) internal(rec <-chan EventInfo) { + for ei := range rec { + var nd node + var eset = internal + t.rw.Lock() + t.root.WalkPath(ei.Path(), func(it node, _ bool) error { + if e := it.Watch[t.rec]; e != 0 && e > eset { + eset = e + } + nd = it + return nil + }) + if eset == internal { + t.rw.Unlock() + continue + } + err := nd.Add(ei.Path()).AddDir(t.recFunc(eset)) + t.rw.Unlock() + if err != nil { + dbgprintf("internal(%p) error: %v", rec, err) + } + } +} + +// watchAdd TODO(rjeczalik) +func (t *nonrecursiveTree) watchAdd(nd node, c chan<- EventInfo, e Event) eventDiff { + if e&recursive != 0 { + diff := nd.Watch.Add(t.rec, e|Create|omit) + nd.Watch.Add(c, e) + return diff + } + return nd.Watch.Add(c, e) +} + +// watchDelMin TODO(rjeczalik) +func (t *nonrecursiveTree) watchDelMin(min Event, nd node, c chan<- EventInfo, e Event) eventDiff { + old, ok := nd.Watch[t.rec] + if ok { + nd.Watch[t.rec] = min + } + diff := nd.Watch.Del(c, e) + if ok { + switch old &^= diff[0] &^ diff[1]; { + case old|internal == internal: + delete(nd.Watch, t.rec) + if set, ok := nd.Watch[nil]; ok && len(nd.Watch) == 1 && set == 0 { + delete(nd.Watch, nil) + } + default: + nd.Watch.Add(t.rec, old|Create) + switch { + case diff == none: + case diff[1]|Create == diff[0]: + diff = none + default: + diff[1] |= Create + } + } + } + return diff +} + +// watchDel TODO(rjeczalik) +func (t *nonrecursiveTree) watchDel(nd node, c chan<- EventInfo, e Event) eventDiff { + return t.watchDelMin(0, nd, c, e) +} + +// Watch TODO(rjeczalik) +func (t *nonrecursiveTree) Watch(path string, c chan<- EventInfo, events ...Event) error { + if c == nil { + panic("notify: Watch using nil channel") + } + // Expanding with empty event set is a nop. + if len(events) == 0 { + return nil + } + path, isrec, err := cleanpath(path) + if err != nil { + return err + } + eset := joinevents(events) + t.rw.Lock() + defer t.rw.Unlock() + nd := t.root.Add(path) + if isrec { + return t.watchrec(nd, c, eset|recursive) + } + return t.watch(nd, c, eset) +} + +func (t *nonrecursiveTree) watch(nd node, c chan<- EventInfo, e Event) (err error) { + diff := nd.Watch.Add(c, e) + switch { + case diff == none: + return nil + case diff[1] == 0: + // TODO(rjeczalik): cleanup this panic after implementation is stable + panic("eset is empty: " + nd.Name) + case diff[0] == 0: + err = t.w.Watch(nd.Name, diff[1]) + default: + err = t.w.Rewatch(nd.Name, diff[0], diff[1]) + } + if err != nil { + nd.Watch.Del(c, diff.Event()) + return err + } + return nil +} + +func (t *nonrecursiveTree) recFunc(e Event) walkFunc { + return func(nd node) error { + switch diff := nd.Watch.Add(t.rec, e|omit|Create); { + case diff == none: + case diff[1] == 0: + // TODO(rjeczalik): cleanup this panic after implementation is stable + panic("eset is empty: " + nd.Name) + case diff[0] == 0: + t.w.Watch(nd.Name, diff[1]) + default: + t.w.Rewatch(nd.Name, diff[0], diff[1]) + } + return nil + } +} + +func (t *nonrecursiveTree) watchrec(nd node, c chan<- EventInfo, e Event) error { + var traverse func(walkFunc) error + // Non-recursive tree listens on Create event for every recursive + // watchpoint in order to automagically set a watch for every + // created directory. + switch diff := nd.Watch.dryAdd(t.rec, e|Create); { + case diff == none: + t.watchAdd(nd, c, e) + nd.Watch.Add(t.rec, e|omit|Create) + return nil + case diff[1] == 0: + // TODO(rjeczalik): cleanup this panic after implementation is stable + panic("eset is empty: " + nd.Name) + case diff[0] == 0: + // TODO(rjeczalik): BFS into directories and skip subtree as soon as first + // recursive watchpoint is encountered. + traverse = nd.AddDir + default: + traverse = nd.Walk + } + // TODO(rjeczalik): account every path that failed to be (re)watched + // and retry. + if err := traverse(t.recFunc(e)); err != nil { + return err + } + t.watchAdd(nd, c, e) + return nil +} + +type walkWatchpointFunc func(Event, node) error + +func (t *nonrecursiveTree) walkWatchpoint(nd node, fn walkWatchpointFunc) error { + type minode struct { + min Event + nd node + } + mnd := minode{nd: nd} + stack := []minode{mnd} +Traverse: + for n := len(stack); n != 0; n = len(stack) { + mnd, stack = stack[n-1], stack[:n-1] + // There must be no recursive watchpoints if the node has no watchpoints + // itself (every node in subtree rooted at recursive watchpoints must + // have at least nil (total) and t.rec watchpoints). + if len(mnd.nd.Watch) != 0 { + switch err := fn(mnd.min, mnd.nd); err { + case nil: + case errSkip: + continue Traverse + default: + return err + } + } + for _, nd := range mnd.nd.Child { + stack = append(stack, minode{mnd.nd.Watch[t.rec], nd}) + } + } + return nil +} + +// Stop TODO(rjeczalik) +func (t *nonrecursiveTree) Stop(c chan<- EventInfo) { + fn := func(min Event, nd node) error { + // TODO(rjeczalik): aggregate watcher errors and retry; in worst case + // forward to the user. + switch diff := t.watchDelMin(min, nd, c, all); { + case diff == none: + return nil + case diff[1] == 0: + t.w.Unwatch(nd.Name) + default: + t.w.Rewatch(nd.Name, diff[0], diff[1]) + } + return nil + } + t.rw.Lock() + err := t.walkWatchpoint(t.root.nd, fn) // TODO(rjeczalik): store max root per c + t.rw.Unlock() + dbgprintf("Stop(%p) error: %v\n", c, err) +} + +// Close TODO(rjeczalik) +func (t *nonrecursiveTree) Close() error { + err := t.w.Close() + close(t.c) + return err +} |