Add pipe package

pipe/pipe.go

@@ -0,0 +1,101 @@
+package pipe
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+)
+
+type Entry struct {
+	Path   string
+	Info   os.FileInfo
+	Error  error
+	Result chan<- interface{}
+}
+
+type Dir struct {
+	Path  string
+	Error error
+
+	Entries [](<-chan interface{})
+	Result  chan<- interface{}
+}
+
+// readDirNames reads the directory named by dirname and returns
+// a sorted list of directory entries.
+// taken from filepath/path.go
+func readDirNames(dirname string) ([]string, error) {
+	f, err := os.Open(dirname)
+	if err != nil {
+		return nil, err
+	}
+	names, err := f.Readdirnames(-1)
+	f.Close()
+	if err != nil {
+		return nil, err
+	}
+	sort.Strings(names)
+	return names, nil
+}
+
+func isDir(fi os.FileInfo) bool {
+	return fi.IsDir()
+}
+
+func isFile(fi os.FileInfo) bool {
+	return fi.Mode()&(os.ModeType|os.ModeCharDevice) == 0
+}
+
+func walk(path string, done chan struct{}, entCh chan<- Entry, dirCh chan<- Dir, res chan<- interface{}) error {
+	info, err := os.Lstat(path)
+	if err != nil {
+		return err
+	}
+
+	if !info.IsDir() {
+		return fmt.Errorf("path is not a directory, cannot walk: %s", path)
+	}
+
+	names, err := readDirNames(path)
+	if err != nil {
+		dirCh <- Dir{Path: path, Error: err}
+		return err
+	}
+
+	entries := make([]<-chan interface{}, 0, len(names))
+
+	for _, name := range names {
+		subpath := filepath.Join(path, name)
+		ch := make(chan interface{}, 1)
+
+		fi, err := os.Lstat(subpath)
+		if err != nil {
+			entries = append(entries, ch)
+			entCh <- Entry{Info: fi, Error: err, Result: ch}
+			continue
+		}
+
+		if isFile(fi) {
+			ch := make(chan interface{}, 1)
+			entCh <- Entry{Info: fi, Path: subpath, Result: ch}
+		} else if isDir(fi) {
+			ch := make(chan interface{}, 1)
+			entries = append(entries, ch)
+			walk(subpath, done, entCh, dirCh, ch)
+		}
+	}
+
+	dirCh <- Dir{Path: path, Entries: entries, Result: res}
+	return nil
+}
+
+// Walk takes a path and sends a Job for each file and directory it finds below
+// the path. When the channel done is closed, processing stops.
+func Walk(path string, done chan struct{}, entCh chan<- Entry, dirCh chan<- Dir) (<-chan interface{}, error) {
+	resCh := make(chan interface{}, 1)
+	err := walk(path, done, entCh, dirCh, resCh)
+	close(entCh)
+	close(dirCh)
+	return resCh, err
+}