ai cooking
Fix file cache writes to avoid partial read race (#241)
authored by
Paul Miller
and committed by
GitHub
78228ebd
8f3666f3
+53
-16
+53
-16
internal/cache/file.go
+53
-16
internal/cache/file.go
···
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}
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if opts.Condition == PutIfNoneMatch {
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f, err := os.OpenFile(fullPath, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0644)
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if err != nil {
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if os.IsExist(err) {
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return ErrAlreadyExists
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}
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return err
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return writeIfNoneMatchAtomic(dir, fullPath, value)
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}
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+
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// TODO: IfMatch support (write only if etag matches).
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return writeAtomic(dir, fullPath, value)
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}
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+
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func writeAtomic(dir, targetPath, value string) error {
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tmpFile, err := os.CreateTemp(dir, ".tmp-*")
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if err != nil {
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return err
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}
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tmpPath := tmpFile.Name()
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defer func() {
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_ = os.Remove(tmpPath)
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}()
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+
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if _, err := tmpFile.WriteString(value); err != nil {
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if closeErr := tmpFile.Close(); closeErr != nil {
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return errors.Join(err, closeErr)
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}
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if _, err := f.WriteString(value); err != nil {
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if closeErr := f.Close(); closeErr != nil {
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return errors.Join(err, closeErr)
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}
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return err
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return err
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}
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if err := tmpFile.Close(); err != nil {
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return err
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}
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return os.Rename(tmpPath, targetPath)
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}
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+
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func writeIfNoneMatchAtomic(dir, targetPath, value string) error {
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tmpFile, err := os.CreateTemp(dir, ".tmp-*")
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if err != nil {
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return err
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}
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tmpPath := tmpFile.Name()
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defer func() {
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_ = os.Remove(tmpPath)
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}()
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+
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if _, err := tmpFile.WriteString(value); err != nil {
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if closeErr := tmpFile.Close(); closeErr != nil {
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return errors.Join(err, closeErr)
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}
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if err := f.Close(); err != nil {
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return err
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return err
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}
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if err := tmpFile.Close(); err != nil {
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return err
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}
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+
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if err := os.Link(tmpPath, targetPath); err != nil {
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if os.IsExist(err) {
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return ErrAlreadyExists
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}
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return nil
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return err
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}
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// TODO: IfMatch support (write only if etag matches).
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return os.WriteFile(fullPath, []byte(value), 0644)
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return nil
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}
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func (fc *FileCache) Delete(_ context.Context, key string) error {