add tests for fswatcher package

internal/fswatcher/fswatcher.go

@@ -0,0 +1,105 @@
+package fswatcher
+
+import (
+	"fmt"
+
+	"github.com/dominicbreuker/pspy/internal/fswatcher/inotify"
+	"github.com/dominicbreuker/pspy/internal/fswatcher/walker"
+)
+
+type Inotify interface {
+	Init() error
+	Watch(dir string) error
+	NumWatchers() int
+	Read(buf []byte) (int, error)
+	ParseNextEvent(buf []byte) (*inotify.Event, uint32, error)
+	Close() error
+}
+
+type Walker interface {
+	Walk(dir string, depth int) (chan string, chan error, chan struct{})
+}
+
+type FSWatcher struct {
+	i           Inotify
+	w           Walker
+	maxWatchers int
+}
+
+func NewFSWatcher() (*FSWatcher, error) {
+	return &FSWatcher{
+		i:           inotify.NewInotify(),
+		w:           walker.NewWalker(),
+		maxWatchers: inotify.MaxWatchers,
+	}, nil
+}
+
+func (iw *FSWatcher) Close() {
+	iw.i.Close()
+}
+
+func (fs *FSWatcher) Init(rdirs, dirs []string) (chan error, chan struct{}) {
+	errCh := make(chan error)
+	doneCh := make(chan struct{})
+
+	go func() {
+		err := fs.i.Init()
+		if err != nil {
+			errCh <- fmt.Errorf("setting up inotify: %v", err)
+		}
+		for _, dir := range rdirs {
+			addWatchers(dir, -1, fs.i, fs.maxWatchers, fs.w, errCh)
+		}
+		for _, dir := range dirs {
+			addWatchers(dir, 0, fs.i, fs.maxWatchers, fs.w, errCh)
+		}
+		close(doneCh)
+	}()
+
+	return errCh, doneCh
+}
+
+func addWatchers(dir string, depth int, i Inotify, maxWatchers int, w Walker, errCh chan error) {
+	dirCh, walkErrCh, doneCh := w.Walk(dir, depth)
+loop:
+	for {
+		if maxWatchers > 0 && i.NumWatchers() >= maxWatchers {
+			close(doneCh)
+			break loop
+		}
+		select {
+		case err := <-walkErrCh:
+			errCh <- fmt.Errorf("adding inotift watchers: %v", err)
+		case dir, ok := <-dirCh:
+			if !ok {
+				break loop
+			}
+			if err := i.Watch(dir); err != nil {
+				errCh <- fmt.Errorf("Can't create watcher: %v", err)
+			}
+		}
+	}
+}
+
+func (fs *FSWatcher) Start(rdirs, dirs []string, errCh chan error) (chan struct{}, chan string, error) {
+	err := fs.i.Init()
+	if err != nil {
+		return nil, nil, fmt.Errorf("setting up inotify: %v", err)
+	}
+
+	for _, dir := range rdirs {
+		addWatchers(dir, -1, fs.i, fs.maxWatchers, fs.w, errCh)
+	}
+	for _, dir := range dirs {
+		addWatchers(dir, 0, fs.i, fs.maxWatchers, fs.w, errCh)
+	}
+
+	triggerCh := make(chan struct{})
+	dataCh := make(chan []byte)
+	go Observe(fs.i, triggerCh, dataCh, errCh)
+
+	eventCh := make(chan string)
+	go parseEvents(fs.i, dataCh, eventCh, errCh)
+
+	return triggerCh, eventCh, nil
+}