41 lines
1.4 KiB
Go
41 lines
1.4 KiB
Go
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// +build windows
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package replacefile
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import (
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"os"
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"syscall"
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"golang.org/x/sys/windows"
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)
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// AtomicRename renames from the source path to the destination path,
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// atomically replacing any file that might already exist at the destination.
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//
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// Typically this operation can succeed only if the source and destination
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// are within the same physical filesystem, so this function is best reserved
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// for cases where the source and destination exist in the same directory and
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// only the local filename differs between them.
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func AtomicRename(source, destination string) error {
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// On Windows, renaming one file over another is not atomic and certain
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// error conditions can result in having only the source file and nothing
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// at the destination file. Instead, we need to call into the MoveFileEx
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// Windows API function, setting two flags to opt in to replacing an
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// existing file.
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srcPtr, err := syscall.UTF16PtrFromString(source)
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if err != nil {
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return &os.LinkError{"replace", source, destination, err}
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}
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destPtr, err := syscall.UTF16PtrFromString(destination)
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if err != nil {
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return &os.LinkError{"replace", source, destination, err}
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}
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flags := uint32(windows.MOVEFILE_REPLACE_EXISTING | windows.MOVEFILE_WRITE_THROUGH)
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err = windows.MoveFileEx(srcPtr, destPtr, flags)
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if err != nil {
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return &os.LinkError{"replace", source, destination, err}
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}
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return nil
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}
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