Method DecodeAll

zstd/decoder.go:319–410

DecodeAll allows stateless decoding of a blob of bytes. Output will be appended to dst, so if the destination size is known you can pre-allocate the destination slice to avoid allocations. DecodeAll can be used concurrently. The Decoder concurrency limits will be respected.

(input, dst []byte)

// DecodeAll can be used concurrently.
// The Decoder concurrency limits will be respected.
func (d *Decoder) DecodeAll(input, dst []byte) ([]byte, error) {
	if d.decoders == nil {
		return dst, ErrDecoderClosed
	}

	// Grab a block decoder and frame decoder.
	block := <-d.decoders
	frame := block.localFrame
	initialSize := len(dst)
	defer func() {
		if debugDecoder {
			printf("re-adding decoder: %p", block)
		}
		frame.rawInput = nil
		frame.bBuf = nil
		if frame.history.decoders.br != nil {
			frame.history.decoders.br.in = nil
			frame.history.decoders.br.cursor = 0
		}
		d.decoders <- block
	}()
	frame.bBuf = input

	for {
		frame.history.reset()
		err := frame.reset(&frame.bBuf)
		if err != nil {
			if err == io.EOF {
				if debugDecoder {
					println("frame reset return EOF")
				}
				return dst, nil
			}
			return dst, err
		}
		if err = d.setDict(frame); err != nil {
			return nil, err
		}
		if frame.WindowSize > d.o.maxWindowSize {
			if debugDecoder {
				println("window size exceeded:", frame.WindowSize, ">", d.o.maxWindowSize)
			}
			return dst, ErrWindowSizeExceeded
		}
		if frame.FrameContentSize != fcsUnknown {
			if frame.FrameContentSize > d.o.maxDecodedSize-uint64(len(dst)-initialSize) {
				if debugDecoder {
					println("decoder size exceeded; fcs:", frame.FrameContentSize, "> mcs:", d.o.maxDecodedSize-uint64(len(dst)-initialSize), "len:", len(dst))
				}
				return dst, ErrDecoderSizeExceeded
			}
			if d.o.limitToCap && frame.FrameContentSize > uint64(cap(dst)-len(dst)) {
				if debugDecoder {
					println("decoder size exceeded; fcs:", frame.FrameContentSize, "> (cap-len)", cap(dst)-len(dst))
				}
				return dst, ErrDecoderSizeExceeded
			}
			if cap(dst)-len(dst) < int(frame.FrameContentSize) {