54 lines
927 B
Go
54 lines
927 B
Go
package ffiwrapper
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import (
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"io"
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"os"
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"sync"
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"golang.org/x/xerrors"
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)
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func toReadableFile(r io.Reader, n int64) (*os.File, func() error, error) {
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f, ok := r.(*os.File)
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if ok {
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return f, func() error { return nil }, nil
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}
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var w *os.File
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f, w, err := os.Pipe()
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if err != nil {
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return nil, nil, err
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}
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var wait sync.Mutex
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var werr error
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wait.Lock()
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go func() {
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defer wait.Unlock()
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var copied int64
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copied, werr = io.CopyN(w, r, n)
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if werr != nil {
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log.Warnf("toReadableFile: copy error: %+v", werr)
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}
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err := w.Close()
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if werr == nil && err != nil {
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werr = err
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log.Warnf("toReadableFile: close error: %+v", err)
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return
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}
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if copied != n {
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log.Warnf("copied different amount than expected: %d != %d", copied, n)
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werr = xerrors.Errorf("copied different amount than expected: %d != %d", copied, n)
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}
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}()
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return f, func() error {
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wait.Lock()
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return werr
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}, nil
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}
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