add vendor

vendor/github.com/siddontang/go/ioutil2/ioutil.go

@@ -0,0 +1,39 @@
+// Copyright 2012, Google Inc. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ioutil2
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+)
+
+// Write file to temp and atomically move when everything else succeeds.
+func WriteFileAtomic(filename string, data []byte, perm os.FileMode) error {
+	dir, name := path.Dir(filename), path.Base(filename) 
+	f, err := ioutil.TempFile(dir, name)
+	if err != nil {
+		return err
+	}
+	n, err := f.Write(data)
+	f.Close()
+	if err == nil && n < len(data) {
+		err = io.ErrShortWrite
+	} else {
+		err = os.Chmod(f.Name(), perm)
+	}
+	if err != nil {
+		os.Remove(f.Name())
+		return err
+	}
+	return os.Rename(f.Name(), filename)
+}
+
+// Check file exists or not
+func FileExists(name string) bool {
+	_, err := os.Stat(name)
+	return !os.IsNotExist(err)
+}

vendor/github.com/siddontang/go/ioutil2/sectionwriter.go

@@ -0,0 +1,69 @@
+package ioutil2
+
+import (
+	"errors"
+	"io"
+)
+
+var ErrExceedLimit = errors.New("write exceed limit")
+
+func NewSectionWriter(w io.WriterAt, off int64, n int64) *SectionWriter {
+	return &SectionWriter{w, off, off, off + n}
+}
+
+type SectionWriter struct {
+	w     io.WriterAt
+	base  int64
+	off   int64
+	limit int64
+}
+
+func (s *SectionWriter) Write(p []byte) (n int, err error) {
+	if s.off >= s.limit {
+		return 0, ErrExceedLimit
+	}
+
+	if max := s.limit - s.off; int64(len(p)) > max {
+		return 0, ErrExceedLimit
+	}
+
+	n, err = s.w.WriteAt(p, s.off)
+	s.off += int64(n)
+	return
+}
+
+var errWhence = errors.New("Seek: invalid whence")
+var errOffset = errors.New("Seek: invalid offset")
+
+func (s *SectionWriter) Seek(offset int64, whence int) (int64, error) {
+	switch whence {
+	default:
+		return 0, errWhence
+	case 0:
+		offset += s.base
+	case 1:
+		offset += s.off
+	case 2:
+		offset += s.limit
+	}
+	if offset < s.base {
+		return 0, errOffset
+	}
+	s.off = offset
+	return offset - s.base, nil
+}
+
+func (s *SectionWriter) WriteAt(p []byte, off int64) (n int, err error) {
+	if off < 0 || off >= s.limit-s.base {
+		return 0, errOffset
+	}
+	off += s.base
+	if max := s.limit - off; int64(len(p)) > max {
+		return 0, ErrExceedLimit
+	}
+
+	return s.w.WriteAt(p, off)
+}
+
+// Size returns the size of the section in bytes.
+func (s *SectionWriter) Size() int64 { return s.limit - s.base }