-
Notifications
You must be signed in to change notification settings - Fork 0
/
dirwatcher.go
260 lines (236 loc) · 5.68 KB
/
dirwatcher.go
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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
package wbgo
import (
"gopkg.in/fsnotify.v1"
"io/ioutil"
"log"
"os"
"path/filepath"
"regexp"
"sort"
"sync"
"time"
)
type dirWatcherOpType int
const (
RELOAD_DELAY = 1000 * time.Millisecond
DIRWATCHER_OP_LIST_CAPACITY = 128
DIRWATCHER_OP_CHANGE = dirWatcherOpType(iota)
DIRWATCHER_OP_REMOVE
)
type DirWatcherClient interface {
LoadFile(path string) error
LiveLoadFile(path string) error
LiveRemoveFile(path string) error
}
type dirWatcherFile struct {
explicit bool
}
type dirWatcherOp struct {
typ dirWatcherOpType
path string
}
type DirWatcher struct {
initMtx sync.Mutex
evMtx sync.Mutex
rx *regexp.Regexp
client DirWatcherClient
watcher *fsnotify.Watcher
started bool
quit chan struct{}
delay time.Duration
loaded map[string]*dirWatcherFile
opsByPath map[string]*dirWatcherOp
opList []*dirWatcherOp
timer *time.Timer
c <-chan time.Time
}
func NewDirWatcher(pattern string, client DirWatcherClient) *DirWatcher {
if rx, err := regexp.Compile(pattern); err != nil {
log.Panicf("invalid loader regexp: %s", pattern)
return nil
} else {
return &DirWatcher{
rx: rx,
client: client,
watcher: nil,
started: false,
quit: make(chan struct{}),
delay: RELOAD_DELAY,
loaded: make(map[string]*dirWatcherFile),
}
}
}
func (dw *DirWatcher) SetDelay(delay time.Duration) {
dw.delay = delay
}
func (dw *DirWatcher) resetOps() {
dw.opsByPath = make(map[string]*dirWatcherOp)
dw.opList = make([]*dirWatcherOp, 0, DIRWATCHER_OP_LIST_CAPACITY)
}
func (dw *DirWatcher) registerFSEvent(ev fsnotify.Event) {
opType := DIRWATCHER_OP_CHANGE
if ev.Op == fsnotify.Remove || ev.Op == fsnotify.Rename {
opType = DIRWATCHER_OP_REMOVE
}
op, found := dw.opsByPath[ev.Name]
if found {
op.typ = opType
} else {
op = &dirWatcherOp{opType, ev.Name}
dw.opsByPath[ev.Name] = op
dw.opList = append(dw.opList, op)
}
if dw.timer != nil {
dw.timer.Reset(dw.delay)
} else {
dw.timer = time.NewTimer(dw.delay)
dw.c = dw.timer.C
}
}
func (dw *DirWatcher) processOp(op *dirWatcherOp) {
dw.evMtx.Lock()
defer dw.evMtx.Unlock()
switch op.typ {
case DIRWATCHER_OP_CHANGE:
Debug.Printf("(re)load: %s", op.path)
// need to check whether the file that possibly doesn't
// satisfy the loader pattern was explicitly loaded
explicit := false
if entry, found := dw.loaded[op.path]; found {
explicit = entry.explicit
}
if err := dw.doLoad(op.path, explicit, true); err != nil {
Warn.Printf(
"warning: failed to load %s: %s", op.path, err)
}
case DIRWATCHER_OP_REMOVE:
Debug.Printf("file removed: %s", op.path)
dw.removePath(op.path)
default:
log.Panicf("invalid loader op %d", op.typ)
}
}
func (dw *DirWatcher) processEvents() {
for _, op := range dw.opList {
dw.processOp(op)
}
dw.resetOps()
}
func (dw *DirWatcher) startWatching() {
dw.initMtx.Lock()
defer dw.initMtx.Unlock()
if dw.started {
return
}
var err error
if dw.watcher, err = fsnotify.NewWatcher(); err != nil {
Warn.Printf("failed to create filesystem watcher: %s", err)
return
}
dw.started = true
dw.resetOps()
go func() {
for {
select {
case ev := <-dw.watcher.Events:
Debug.Printf("fs change event: %s", ev)
dw.registerFSEvent(ev)
case err := <-dw.watcher.Errors:
Error.Printf("watcher error: %s", err)
case <-dw.c:
Debug.Printf("reload timer fired")
dw.processEvents()
case <-dw.quit:
return
}
}
}()
}
func (dw *DirWatcher) shouldLoadFile(fileName string) bool {
return dw.rx.MatchString(fileName)
}
func (dw *DirWatcher) loadDir(filePath string, reloaded bool) error {
Debug.Printf("loadDir: %s", filePath)
entries, err := ioutil.ReadDir(filePath)
if err != nil {
return err
}
if err = dw.watcher.Add(filePath); err != nil {
Debug.Printf("loadDir: failed to watch %s: %s", filePath, err)
}
for _, fi := range entries {
fullPath := filepath.Join(filePath, fi.Name())
Debug.Printf("loadDir: entry: %s", fullPath)
var err error
switch {
case fi.IsDir():
err = dw.loadDir(fullPath, reloaded)
case dw.shouldLoadFile(fi.Name()):
err = dw.loadFile(fullPath, reloaded, false)
}
if err != nil {
Warn.Printf("couldn't load %s: %s", fullPath, err)
}
}
return nil
}
func (dw *DirWatcher) loadFile(filePath string, reloaded, explicit bool) error {
dw.loaded[filePath] = &dirWatcherFile{explicit}
if reloaded {
Info.Printf("reloading file: %s", filePath)
return dw.client.LiveLoadFile(filePath)
} else {
return dw.client.LoadFile(filePath)
}
}
func (dw *DirWatcher) doLoad(filePath string, explicit bool, reloaded bool) error {
dw.startWatching()
fi, err := os.Stat(filePath)
switch {
case err != nil:
return err
case fi.IsDir():
return dw.loadDir(filePath, reloaded)
case explicit:
dw.watcher.Add(filePath)
fallthrough
case dw.shouldLoadFile(fi.Name()):
return dw.loadFile(filePath, reloaded, explicit)
default:
Debug.Printf("skipping loading of non-matching file %s", filePath)
return nil
}
}
func (dw *DirWatcher) removePath(filePath string) {
if dw.loaded[filePath] != nil {
dw.client.LiveRemoveFile(filePath)
delete(dw.loaded, filePath)
return
}
// assume it's directory removal and try to find subpaths
pathList := make([]string, 0)
for p, _ := range dw.loaded {
if IsSubpath(filePath, p) {
pathList = append(pathList, p)
}
}
sort.Strings(pathList)
for _, p := range pathList {
dw.removePath(p)
}
}
func (dw *DirWatcher) Load(filePath string) error {
dw.evMtx.Lock()
defer dw.evMtx.Unlock()
return dw.doLoad(filePath, true, false)
}
func (dw *DirWatcher) Stop() {
dw.initMtx.Lock()
defer dw.initMtx.Unlock()
if !dw.started {
return
}
dw.quit <- struct{}{}
dw.watcher.Close()
dw.started = false
}