Wrap Go's awful decompressor routines to allow feeding them data in chunks. For example: sd := NewStreamDecompressor(zlib.NewReader, output) sd(chunk, false) ... sd(last_chunk, true) after this call, calling sd() further will just return io.EOF. To close the decompressor at any time, call sd(nil, tr
(constructor func(io.Reader) (io.ReadCloser, error), output io.Writer)
| 37 | // To close the decompressor at any time, call sd(nil, true). |
| 38 | // Note: output.Write() may be called from a different thread, but only while the main thread is in sd() |
| 39 | func NewStreamDecompressor(constructor func(io.Reader) (io.ReadCloser, error), output io.Writer) StreamDecompressor { |
| 40 | if constructor == nil { // identity decompressor |
| 41 | var err error |
| 42 | return func(chunk []byte, is_last bool) error { |
| 43 | if err != nil { |
| 44 | return err |
| 45 | } |
| 46 | if len(chunk) > 0 { |
| 47 | _, err = output.Write(chunk) |
| 48 | } |
| 49 | if is_last { |
| 50 | if err == nil { |
| 51 | err = io.EOF |
| 52 | return nil |
| 53 | } |
| 54 | } |
| 55 | return err |
| 56 | } |
| 57 | } |
| 58 | pipe_r, pipe_w := io.Pipe() |
| 59 | pr := pipe_reader{pr: pipe_r} |
| 60 | finished := make(chan error, 1) |
| 61 | finished_err := errors.New("finished") |
| 62 | go func() { |
| 63 | var err error |
| 64 | defer func() { |
| 65 | finished <- err |
| 66 | }() |
| 67 | var impl io.ReadCloser |
| 68 | impl, err = constructor(&pr) |
| 69 | if err != nil { |
| 70 | pipe_r.CloseWithError(err) |
| 71 | return |
| 72 | } |
| 73 | _, err = io.Copy(output, impl) |
| 74 | cerr := impl.Close() |
| 75 | if err == nil { |
| 76 | err = cerr |
| 77 | } |
| 78 | if err == nil { |
| 79 | err = finished_err |
| 80 | } |
| 81 | pipe_r.CloseWithError(err) |
| 82 | }() |
| 83 | |
| 84 | var iter_err error |
| 85 | return func(chunk []byte, is_last bool) error { |
| 86 | if iter_err != nil { |
| 87 | if iter_err == finished_err { |
| 88 | iter_err = io.EOF |
| 89 | } |
| 90 | return iter_err |
| 91 | } |
| 92 | if len(chunk) > 0 { |
| 93 | var n int |
| 94 | n, iter_err = pipe_w.Write(chunk) |
| 95 | if iter_err != nil && iter_err != finished_err { |
| 96 | return iter_err |