60 lines
1.5 KiB
Go
60 lines
1.5 KiB
Go
// Copyright (C) 2015 The Syncthing Authors.
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this file,
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// You can obtain one at https://mozilla.org/MPL/2.0/.
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package fs
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import (
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"fmt"
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"path/filepath"
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"runtime"
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"strings"
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"github.com/syncthing/syncthing/lib/sha256"
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)
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const (
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WindowsTempPrefix = "~syncthing~"
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UnixTempPrefix = ".syncthing."
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)
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func tempPrefix() string {
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if runtime.GOOS == "windows" {
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return WindowsTempPrefix
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} else {
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return UnixTempPrefix
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}
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}
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// Real filesystems usually handle 255 bytes. encfs has varying and
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// confusing file name limits. We take a safe way out and switch to hashing
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// quite early.
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const maxFilenameLength = 160 - len(UnixTempPrefix) - len(".tmp")
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// IsTemporary is true if the file name has the temporary prefix. Regardless
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// of the normally used prefix, the standard Windows and Unix temp prefixes
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// are always recognized as temp files.
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func IsTemporary(name string) bool {
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name = filepath.Base(name)
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return strings.HasPrefix(name, WindowsTempPrefix) ||
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strings.HasPrefix(name, UnixTempPrefix)
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}
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func TempNameWithPrefix(name, prefix string) string {
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tdir := filepath.Dir(name)
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tbase := filepath.Base(name)
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var tname string
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if len(tbase) > maxFilenameLength {
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tname = fmt.Sprintf("%s%x.tmp", prefix, sha256.Sum256([]byte(tbase)))
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} else {
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tname = prefix + tbase + ".tmp"
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}
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return filepath.Join(tdir, tname)
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}
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func TempName(name string) string {
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return TempNameWithPrefix(name, tempPrefix())
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}
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