| 43 | } |
| 44 | |
| 45 | func (mb *MultiBufferByteGetter) rebuffer(newOffset int64) error { |
| 46 | partNum := int(newOffset / mb.BufSize) |
| 47 | partOffset := int64(partNum) * mb.BufSize |
| 48 | newBuf := make([]byte, mb.BufSize) |
| 49 | n, err := mb.File.ReadAt(newBuf, partOffset) |
| 50 | var isEOF bool |
| 51 | if err == io.EOF { |
| 52 | newBuf = newBuf[:n] |
| 53 | isEOF = true |
| 54 | } |
| 55 | if err != nil { |
| 56 | return err |
| 57 | } |
| 58 | var newBuffers [][]byte |
| 59 | if len(mb.Buffers) > 0 { |
| 60 | firstBufPartNum := int(mb.Offset / mb.BufSize) |
| 61 | lastBufPartNum := int((mb.Offset + int64(mb.bufSize())) / mb.BufSize) |
| 62 | if firstBufPartNum == partNum+1 { |
| 63 | newBuffers = [][]byte{newBuf, mb.Buffers[0]} |
| 64 | } else if lastBufPartNum == partNum-1 { |
| 65 | newBuffers = [][]byte{mb.Buffers[0], newBuf} |
| 66 | } else { |
| 67 | newBuffers = [][]byte{newBuf} |
| 68 | } |
| 69 | } else { |
| 70 | newBuffers = [][]byte{newBuf} |
| 71 | } |
| 72 | mb.Buffers = newBuffers |
| 73 | mb.Offset = partOffset |
| 74 | mb.EOF = isEOF |
| 75 | return nil |
| 76 | } |
| 77 | |
| 78 | func (mb *MultiBufferByteGetter) GetByte(offset int64) (byte, error) { |
| 79 | b, ok := mb.readFromBuffer(offset) |