Method Convert

zstd/snappy.go:82–282

Convert the Snappy stream supplied in 'in' and write the zStandard stream to 'w'. If any error is detected on the Snappy stream it is returned. The number of bytes written is returned.

(in io.Reader, w io.Writer)

// If any error is detected on the Snappy stream it is returned.
// The number of bytes written is returned.
func (r *SnappyConverter) Convert(in io.Reader, w io.Writer) (int64, error) {
	initPredefined()
	r.err = nil
	r.r = in
	if r.block == nil {
		r.block = &blockEnc{}
		r.block.init()
	}
	r.block.initNewEncode()
	if len(r.buf) != snappyMaxEncodedLenOfMaxBlockSize+snappyChecksumSize {
		r.buf = make([]byte, snappyMaxEncodedLenOfMaxBlockSize+snappyChecksumSize)
	}
	r.block.litEnc.Reuse = huff0.ReusePolicyNone
	var written int64
	var readHeader bool
	{
		header := frameHeader{WindowSize: snappyMaxBlockSize}.appendTo(r.buf[:0])

		var n int
		n, r.err = w.Write(header)
		if r.err != nil {
			return written, r.err
		}
		written += int64(n)
	}

	for {
		if !r.readFull(r.buf[:4], true) {
			// Add empty last block
			r.block.reset(nil)
			r.block.last = true
			err := r.block.encodeLits(r.block.literals, false)
			if err != nil {
				return written, err
			}
			n, err := w.Write(r.block.output)
			if err != nil {
				return written, err
			}
			written += int64(n)

			return written, r.err
		}
		chunkType := r.buf[0]
		if !readHeader {
			if chunkType != chunkTypeStreamIdentifier {
				println("chunkType != chunkTypeStreamIdentifier", chunkType)
				r.err = ErrSnappyCorrupt
				return written, r.err
			}
			readHeader = true
		}
		chunkLen := int(r.buf[1]) | int(r.buf[2])<<8 | int(r.buf[3])<<16
		if chunkLen > len(r.buf) {
			println("chunkLen > len(r.buf)", chunkType)
			r.err = ErrSnappyUnsupported
			return written, r.err
		}