initial commit

watcher.go

@@ -0,0 +1,140 @@
+// There is some dead code in here because I pulled out the parts I needed to get it working, deal with this later lol.
+
+package main
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/bmatcuk/doublestar"
+	"github.com/fsnotify/fsnotify"
+)
+
+type globList []string
+
+func (g *globList) Matches(value string) bool {
+	for _, v := range *g {
+		if match, err := filepath.Match(v, value); err != nil {
+			log.Fatalf("Bad pattern \"%s\": %s", v, err.Error())
+		} else if match {
+			return true
+		}
+	}
+	return false
+}
+
+func matchesPattern(pattern []string, path string) bool {
+	for _, p := range pattern {
+		if matched, _ := doublestar.Match(p, path); matched {
+			return true
+		}
+	}
+	return false
+}
+
+func directoryShouldBeTracked(cfg *WatcherConfig, path string) bool {
+	base := filepath.Dir(path)
+	return matchesPattern(cfg.pattern, path) && !cfg.excludedDirs.Matches(base)
+}
+
+func pathMatches(cfg *WatcherConfig, path string) bool {
+	return matchesPattern(cfg.pattern, path)
+}
+
+type WatcherConfig struct {
+	excludedDirs globList
+	pattern      globList
+}
+
+type FileWatcher interface {
+	Close() error
+	AddFiles() error
+	add(path string) error
+	Watch(jobs chan<- string)
+	getConfig() *WatcherConfig
+}
+
+type NotifyWatcher struct {
+	watcher *fsnotify.Watcher
+	cfg     *WatcherConfig
+}
+
+func (n NotifyWatcher) Close() error {
+	return n.watcher.Close()
+}
+
+func (n NotifyWatcher) AddFiles() error {
+	return addFiles(n)
+}
+
+func (n NotifyWatcher) Watch(jobs chan<- string) {
+	for {
+		select {
+		case ev := <-n.watcher.Events:
+			if ev.Op&fsnotify.Remove == fsnotify.Remove || ev.Op&fsnotify.Write == fsnotify.Write || ev.Op&fsnotify.Create == fsnotify.Create {
+				// Assume it is a directory and track it.
+				if directoryShouldBeTracked(n.cfg, ev.Name) {
+					n.watcher.Add(ev.Name)
+				}
+				if pathMatches(n.cfg, ev.Name) {
+					jobs <- ev.Name
+				}
+			}
+
+		case err := <-n.watcher.Errors:
+			if v, ok := err.(*os.SyscallError); ok {
+				if v.Err == syscall.EINTR {
+					continue
+				}
+				log.Fatal("watcher.Error: SyscallError:", v)
+			}
+			log.Fatal("watcher.Error:", err)
+		}
+	}
+}
+
+func (n NotifyWatcher) add(path string) error {
+	return n.watcher.Add(path)
+}
+
+func (n NotifyWatcher) getConfig() *WatcherConfig {
+	return n.cfg
+}
+
+func NewWatcher(cfg *WatcherConfig) (FileWatcher, error) {
+	if cfg == nil {
+		err := errors.New("no config specified")
+		return nil, err
+	}
+	w, err := fsnotify.NewWatcher()
+	if err != nil {
+		return nil, err
+	}
+	return NotifyWatcher{
+		watcher: w,
+		cfg:     cfg,
+	}, nil
+}
+
+func addFiles(fw FileWatcher) error {
+	cfg := fw.getConfig()
+	for _, pattern := range cfg.pattern {
+		matches, err := doublestar.Glob(pattern)
+		if err != nil {
+			log.Fatalf("Bad pattern \"%s\": %s", pattern, err.Error())
+		}
+		for _, match := range matches {
+			if directoryShouldBeTracked(cfg, match) {
+				if err := fw.add(match); err != nil {
+					return fmt.Errorf("FileWatcher.Add(): %v", err)
+				}
+			}
+		}
+
+	}
+	return nil
+}