Macaron 1.5 (#12596)

* update macaron to v1.5 of fork

* update macaron to v1.5 of fork

* test gzip PR

* add push method impl to context_tests

* use proper gzip commit

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

vendor/github.com/klauspost/compress/zstd/decoder.go

@@ -23,17 +23,15 @@ type Decoder struct {
 	// Unreferenced decoders, ready for use.
 	decoders chan *blockDec
 
-	// Unreferenced decoders, ready for use.
-	frames chan *frameDec
-
 	// Streams ready to be decoded.
 	stream chan decodeStream
 
 	// Current read position used for Reader functionality.
 	current decoderState
 
-	// Custom dictionaries
-	dicts map[uint32]struct{}
+	// Custom dictionaries.
+	// Always uses copies.
+	dicts map[uint32]dict
 
 	// streamWg is the waitgroup for all streams
 	streamWg sync.WaitGroup
@@ -66,7 +64,7 @@ var (
 // A Decoder can be used in two modes:
 //
 // 1) As a stream, or
-// 2) For stateless decoding using DecodeAll or DecodeBuffer.
+// 2) For stateless decoding using DecodeAll.
 //
 // Only a single stream can be decoded concurrently, but the same decoder
 // can run multiple concurrent stateless decodes. It is even possible to
@@ -87,12 +85,19 @@ func NewReader(r io.Reader, opts ...DOption) (*Decoder, error) {
 	d.current.output = make(chan decodeOutput, d.o.concurrent)
 	d.current.flushed = true
 
+	// Transfer option dicts.
+	d.dicts = make(map[uint32]dict, len(d.o.dicts))
+	for _, dc := range d.o.dicts {
+		d.dicts[dc.id] = dc
+	}
+	d.o.dicts = nil
+
 	// Create decoders
 	d.decoders = make(chan *blockDec, d.o.concurrent)
-	d.frames = make(chan *frameDec, d.o.concurrent)
 	for i := 0; i < d.o.concurrent; i++ {
-		d.frames <- newFrameDec(d.o)
-		d.decoders <- newBlockDec(d.o.lowMem)
+		dec := newBlockDec(d.o.lowMem)
+		dec.localFrame = newFrameDec(d.o)
+		d.decoders <- dec
 	}
 
 	if r == nil {
@@ -169,7 +174,12 @@ func (d *Decoder) Reset(r io.Reader) error {
 			println("*bytes.Buffer detected, doing sync decode, len:", bb.Len())
 		}
 		b := bb.Bytes()
-		dst, err := d.DecodeAll(b, nil)
+		var dst []byte
+		if cap(d.current.b) > 0 {
+			dst = d.current.b
+		}
+
+		dst, err := d.DecodeAll(b, dst[:0])
 		if err == nil {
 			err = io.EOF
 		}
@@ -277,23 +287,31 @@ func (d *Decoder) DecodeAll(input, dst []byte) ([]byte, error) {
 	}
 
 	// Grab a block decoder and frame decoder.
-	block, frame := <-d.decoders, <-d.frames
+	block := <-d.decoders
+	frame := block.localFrame
 	defer func() {
 		if debug {
 			printf("re-adding decoder: %p", block)
 		}
-		d.decoders <- block
 		frame.rawInput = nil
 		frame.bBuf = nil
-		d.frames <- frame
+		d.decoders <- block
 	}()
 	frame.bBuf = input
 
 	for {
+		frame.history.reset()
 		err := frame.reset(&frame.bBuf)
 		if err == io.EOF {
 			return dst, nil
 		}
+		if frame.DictionaryID != nil {
+			dict, ok := d.dicts[*frame.DictionaryID]
+			if !ok {
+				return nil, ErrUnknownDictionary
+			}
+			frame.history.setDict(&dict)
+		}
 		if err != nil {
 			return dst, err
 		}
@@ -456,10 +474,19 @@ func (d *Decoder) startStreamDecoder(inStream chan decodeStream) {
 		br := readerWrapper{r: stream.r}
 	decodeStream:
 		for {
+			frame.history.reset()
 			err := frame.reset(&br)
 			if debug && err != nil {
 				println("Frame decoder returned", err)
 			}
+			if err == nil && frame.DictionaryID != nil {
+				dict, ok := d.dicts[*frame.DictionaryID]
+				if !ok {
+					err = ErrUnknownDictionary
+				} else {
+					frame.history.setDict(&dict)
+				}
+			}
 			if err != nil {
 				stream.output <- decodeOutput{
 					err: err,