// 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 (
"errors"
"os"
"path/filepath"
"strings"
)
const all = ^Event(0)
const sep = string(os.PathSeparator)
var errDepth = errors.New("exceeded allowed iteration count (circular symlink?)")
func min(i, j int) int {
if i > j {
return j
}
return i
}
func max(i, j int) int {
if i < j {
return j
}
return i
}
// must panics if err is non-nil.
func must(err error) {
if err != nil {
panic(err)
}
}
// nonil gives first non-nil error from the given arguments.
func nonil(err ...error) error {
for _, err := range err {
if err != nil {
return err
}
}
return nil
}
func cleanpath(path string) (realpath string, isrec bool, err error) {
if strings.HasSuffix(path, "...") {
isrec = true
path = path[:len(path)-3]
}
if path, err = filepath.Abs(path); err != nil {
return "", false, err
}
if path, err = canonical(path); err != nil {
return "", false, err
}
return path, isrec, nil
}
// canonical resolves any symlink in the given path and returns it in a clean form.
// It expects the path to be absolute. It fails to resolve circular symlinks by
// maintaining a simple iteration limit.
func canonical(p string) (string, error) {
p, err := filepath.Abs(p)
if err != nil {
return "", err
}
for i, j, depth := 1, 0, 1; i < len(p); i, depth = i+1, depth+1 {
if depth > 128 {
return "", &os.PathError{Op: "canonical", Path: p, Err: errDepth}
}
if j = strings.IndexRune(p[i:], '/'); j == -1 {
j, i = i, len(p)
} else {
j, i = i, i+j
}
fi, err := os.Lstat(p[:i])
if err != nil {
return "", err
}
if fi.Mode()&os.ModeSymlink == os.ModeSymlink {
s, err := os.Readlink(p[:i])
if err != nil {
return "", err
}
if filepath.IsAbs(s) {
p = "/" + s + p[i:]
} else {
p = p[:j] + s + p[i:]
}
i = 1 // no guarantee s is canonical, start all over
}
}
return filepath.Clean(p), nil
}
func joinevents(events []Event) (e Event) {
if len(events) == 0 {
e = All
} else {
for _, event := range events {
e |= event
}
}
return
}
func split(s string) (string, string) {
if i := lastIndexSep(s); i != -1 {
return s[:i], s[i+1:]
}
return "", s
}
func base(s string) string {
if i := lastIndexSep(s); i != -1 {
return s[i+1:]
}
return s
}
func indexbase(root, name string) int {
if n, m := len(root), len(name); m >= n && name[:n] == root &&
(n == m || name[n] == os.PathSeparator) {
return min(n+1, m)
}
return -1
}
func indexSep(s string) int {
for i := 0; i < len(s); i++ {
if s[i] == os.PathSeparator {
return i
}
}
return -1
}
func lastIndexSep(s string) int {
for i := len(s) - 1; i >= 0; i-- {
if s[i] == os.PathSeparator {
return i
}
}
return -1
}
