--- /dev/null
+// Copyright ©2015 The Go Authors
+// Copyright ©2015 Steve Francia <spf@spf13.com>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+ "bytes"
+ "io"
+ "os"
+ "path/filepath"
+ "sort"
+ "strconv"
+ "sync"
+ "time"
+)
+
+// byName implements sort.Interface.
+type byName []os.FileInfo
+
+func (f byName) Len() int { return len(f) }
+func (f byName) Less(i, j int) bool { return f[i].Name() < f[j].Name() }
+func (f byName) Swap(i, j int) { f[i], f[j] = f[j], f[i] }
+
+// ReadDir reads the directory named by dirname and returns
+// a list of sorted directory entries.
+func (a Afero) ReadDir(dirname string) ([]os.FileInfo, error) {
+ return ReadDir(a.Fs, dirname)
+}
+
+func ReadDir(fs Fs, dirname string) ([]os.FileInfo, error) {
+ f, err := fs.Open(dirname)
+ if err != nil {
+ return nil, err
+ }
+ list, err := f.Readdir(-1)
+ f.Close()
+ if err != nil {
+ return nil, err
+ }
+ sort.Sort(byName(list))
+ return list, nil
+}
+
+// ReadFile reads the file named by filename and returns the contents.
+// A successful call returns err == nil, not err == EOF. Because ReadFile
+// reads the whole file, it does not treat an EOF from Read as an error
+// to be reported.
+func (a Afero) ReadFile(filename string) ([]byte, error) {
+ return ReadFile(a.Fs, filename)
+}
+
+func ReadFile(fs Fs, filename string) ([]byte, error) {
+ f, err := fs.Open(filename)
+ if err != nil {
+ return nil, err
+ }
+ defer f.Close()
+ // It's a good but not certain bet that FileInfo will tell us exactly how much to
+ // read, so let's try it but be prepared for the answer to be wrong.
+ var n int64
+
+ if fi, err := f.Stat(); err == nil {
+ // Don't preallocate a huge buffer, just in case.
+ if size := fi.Size(); size < 1e9 {
+ n = size
+ }
+ }
+ // As initial capacity for readAll, use n + a little extra in case Size is zero,
+ // and to avoid another allocation after Read has filled the buffer. The readAll
+ // call will read into its allocated internal buffer cheaply. If the size was
+ // wrong, we'll either waste some space off the end or reallocate as needed, but
+ // in the overwhelmingly common case we'll get it just right.
+ return readAll(f, n+bytes.MinRead)
+}
+
+// readAll reads from r until an error or EOF and returns the data it read
+// from the internal buffer allocated with a specified capacity.
+func readAll(r io.Reader, capacity int64) (b []byte, err error) {
+ buf := bytes.NewBuffer(make([]byte, 0, capacity))
+ // If the buffer overflows, we will get bytes.ErrTooLarge.
+ // Return that as an error. Any other panic remains.
+ defer func() {
+ e := recover()
+ if e == nil {
+ return
+ }
+ if panicErr, ok := e.(error); ok && panicErr == bytes.ErrTooLarge {
+ err = panicErr
+ } else {
+ panic(e)
+ }
+ }()
+ _, err = buf.ReadFrom(r)
+ return buf.Bytes(), err
+}
+
+// ReadAll reads from r until an error or EOF and returns the data it read.
+// A successful call returns err == nil, not err == EOF. Because ReadAll is
+// defined to read from src until EOF, it does not treat an EOF from Read
+// as an error to be reported.
+func ReadAll(r io.Reader) ([]byte, error) {
+ return readAll(r, bytes.MinRead)
+}
+
+// WriteFile writes data to a file named by filename.
+// If the file does not exist, WriteFile creates it with permissions perm;
+// otherwise WriteFile truncates it before writing.
+func (a Afero) WriteFile(filename string, data []byte, perm os.FileMode) error {
+ return WriteFile(a.Fs, filename, data, perm)
+}
+
+func WriteFile(fs Fs, filename string, data []byte, perm os.FileMode) error {
+ f, err := fs.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
+ if err != nil {
+ return err
+ }
+ n, err := f.Write(data)
+ if err == nil && n < len(data) {
+ err = io.ErrShortWrite
+ }
+ if err1 := f.Close(); err == nil {
+ err = err1
+ }
+ return err
+}
+
+// Random number state.
+// We generate random temporary file names so that there's a good
+// chance the file doesn't exist yet - keeps the number of tries in
+// TempFile to a minimum.
+var rand uint32
+var randmu sync.Mutex
+
+func reseed() uint32 {
+ return uint32(time.Now().UnixNano() + int64(os.Getpid()))
+}
+
+func nextSuffix() string {
+ randmu.Lock()
+ r := rand
+ if r == 0 {
+ r = reseed()
+ }
+ r = r*1664525 + 1013904223 // constants from Numerical Recipes
+ rand = r
+ randmu.Unlock()
+ return strconv.Itoa(int(1e9 + r%1e9))[1:]
+}
+
+// TempFile creates a new temporary file in the directory dir
+// with a name beginning with prefix, opens the file for reading
+// and writing, and returns the resulting *File.
+// If dir is the empty string, TempFile uses the default directory
+// for temporary files (see os.TempDir).
+// Multiple programs calling TempFile simultaneously
+// will not choose the same file. The caller can use f.Name()
+// to find the pathname of the file. It is the caller's responsibility
+// to remove the file when no longer needed.
+func (a Afero) TempFile(dir, prefix string) (f File, err error) {
+ return TempFile(a.Fs, dir, prefix)
+}
+
+func TempFile(fs Fs, dir, prefix string) (f File, err error) {
+ if dir == "" {
+ dir = os.TempDir()
+ }
+
+ nconflict := 0
+ for i := 0; i < 10000; i++ {
+ name := filepath.Join(dir, prefix+nextSuffix())
+ f, err = fs.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)
+ if os.IsExist(err) {
+ if nconflict++; nconflict > 10 {
+ randmu.Lock()
+ rand = reseed()
+ randmu.Unlock()
+ }
+ continue
+ }
+ break
+ }
+ return
+}
+
+// TempDir creates a new temporary directory in the directory dir
+// with a name beginning with prefix and returns the path of the
+// new directory. If dir is the empty string, TempDir uses the
+// default directory for temporary files (see os.TempDir).
+// Multiple programs calling TempDir simultaneously
+// will not choose the same directory. It is the caller's responsibility
+// to remove the directory when no longer needed.
+func (a Afero) TempDir(dir, prefix string) (name string, err error) {
+ return TempDir(a.Fs, dir, prefix)
+}
+func TempDir(fs Fs, dir, prefix string) (name string, err error) {
+ if dir == "" {
+ dir = os.TempDir()
+ }
+
+ nconflict := 0
+ for i := 0; i < 10000; i++ {
+ try := filepath.Join(dir, prefix+nextSuffix())
+ err = fs.Mkdir(try, 0700)
+ if os.IsExist(err) {
+ if nconflict++; nconflict > 10 {
+ randmu.Lock()
+ rand = reseed()
+ randmu.Unlock()
+ }
+ continue
+ }
+ if err == nil {
+ name = try
+ }
+ break
+ }
+ return
+}
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