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-rw-r--r--src/os/tempfile.go125
1 files changed, 125 insertions, 0 deletions
diff --git a/src/os/tempfile.go b/src/os/tempfile.go
new file mode 100644
index 0000000..1ad44f1
--- /dev/null
+++ b/src/os/tempfile.go
@@ -0,0 +1,125 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package os
+
+import "errors"
+
+// fastrand provided by runtime.
+// 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.
+func fastrand() uint32
+
+func nextRandom() string {
+ return uitoa(uint(fastrand()))
+}
+
+// CreateTemp creates a new temporary file in the directory dir,
+// opens the file for reading and writing, and returns the resulting file.
+// The filename is generated by taking pattern and adding a random string to the end.
+// If pattern includes a "*", the random string replaces the last "*".
+// If dir is the empty string, CreateTemp uses the default directory for temporary files, as returned by TempDir.
+// Multiple programs or goroutines calling CreateTemp simultaneously will not choose the same file.
+// The caller can use the file's Name method to find the pathname of the file.
+// It is the caller's responsibility to remove the file when it is no longer needed.
+func CreateTemp(dir, pattern string) (*File, error) {
+ if dir == "" {
+ dir = TempDir()
+ }
+
+ prefix, suffix, err := prefixAndSuffix(pattern)
+ if err != nil {
+ return nil, &PathError{Op: "createtemp", Path: pattern, Err: err}
+ }
+ prefix = joinPath(dir, prefix)
+
+ try := 0
+ for {
+ name := prefix + nextRandom() + suffix
+ f, err := OpenFile(name, O_RDWR|O_CREATE|O_EXCL, 0600)
+ if IsExist(err) {
+ if try++; try < 10000 {
+ continue
+ }
+ return nil, &PathError{Op: "createtemp", Path: dir + string(PathSeparator) + prefix + "*" + suffix, Err: ErrExist}
+ }
+ return f, err
+ }
+}
+
+var errPatternHasSeparator = errors.New("pattern contains path separator")
+
+// prefixAndSuffix splits pattern by the last wildcard "*", if applicable,
+// returning prefix as the part before "*" and suffix as the part after "*".
+func prefixAndSuffix(pattern string) (prefix, suffix string, err error) {
+ for i := 0; i < len(pattern); i++ {
+ if IsPathSeparator(pattern[i]) {
+ return "", "", errPatternHasSeparator
+ }
+ }
+ if pos := lastIndex(pattern, '*'); pos != -1 {
+ prefix, suffix = pattern[:pos], pattern[pos+1:]
+ } else {
+ prefix = pattern
+ }
+ return prefix, suffix, nil
+}
+
+// MkdirTemp creates a new temporary directory in the directory dir
+// and returns the pathname of the new directory.
+// The new directory's name is generated by adding a random string to the end of pattern.
+// If pattern includes a "*", the random string replaces the last "*" instead.
+// If dir is the empty string, MkdirTemp uses the default directory for temporary files, as returned by TempDir.
+// Multiple programs or goroutines calling MkdirTemp simultaneously will not choose the same directory.
+// It is the caller's responsibility to remove the directory when it is no longer needed.
+func MkdirTemp(dir, pattern string) (string, error) {
+ if dir == "" {
+ dir = TempDir()
+ }
+
+ prefix, suffix, err := prefixAndSuffix(pattern)
+ if err != nil {
+ return "", &PathError{Op: "mkdirtemp", Path: pattern, Err: err}
+ }
+ prefix = joinPath(dir, prefix)
+
+ try := 0
+ for {
+ name := prefix + nextRandom() + suffix
+ err := Mkdir(name, 0700)
+ if err == nil {
+ return name, nil
+ }
+ if IsExist(err) {
+ if try++; try < 10000 {
+ continue
+ }
+ return "", &PathError{Op: "mkdirtemp", Path: dir + string(PathSeparator) + prefix + "*" + suffix, Err: ErrExist}
+ }
+ if IsNotExist(err) {
+ if _, err := Stat(dir); IsNotExist(err) {
+ return "", err
+ }
+ }
+ return "", err
+ }
+}
+
+func joinPath(dir, name string) string {
+ if len(dir) > 0 && IsPathSeparator(dir[len(dir)-1]) {
+ return dir + name
+ }
+ return dir + string(PathSeparator) + name
+}
+
+// LastIndexByte from the strings package.
+func lastIndex(s string, sep byte) int {
+ for i := len(s) - 1; i >= 0; i-- {
+ if s[i] == sep {
+ return i
+ }
+ }
+ return -1
+}