43 lines
1018 B
Go
43 lines
1018 B
Go
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// Copyright (C) 2019 Storj Labs, Inc.
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// See LICENSE for copying information.
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package fpath
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import (
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"io/ioutil"
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"os"
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"path/filepath"
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"github.com/zeebo/errs"
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)
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// AtomicWriteFile is a helper to atomically write the data to the outfile.
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func AtomicWriteFile(outfile string, data []byte, mode os.FileMode) (err error) {
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// TODO: provide better atomicity guarantees, like fsyncing the parent
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// directory and, on windows, using MoveFileEx with MOVEFILE_WRITE_THROUGH.
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fh, err := ioutil.TempFile(filepath.Dir(outfile), filepath.Base(outfile))
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if err != nil {
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return errs.Wrap(err)
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}
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defer func() {
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if err != nil {
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err = errs.Combine(err, fh.Close())
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err = errs.Combine(err, os.Remove(fh.Name()))
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}
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}()
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if _, err := fh.Write(data); err != nil {
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return errs.Wrap(err)
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}
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if err := fh.Sync(); err != nil {
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return errs.Wrap(err)
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}
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if err := fh.Close(); err != nil {
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return errs.Wrap(err)
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}
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if err := os.Rename(fh.Name(), outfile); err != nil {
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return errs.Wrap(err)
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}
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return nil
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}
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