transport/grpchttp2: add http2.Framer bridge

internal/transport/grpchttp2/errors.go

@@ -70,3 +70,9 @@
 	}
 	return fmt.Sprintf("unknown error code %#x", uint32(err))
 }
+
+type connError ErrCode
+
+func (err connError) Error() string {
+	return fmt.Sprintf("connection error: %s", ErrCode(err))
+}

internal/transport/grpchttp2/framer.go

@@ -53,6 +53,10 @@
 	FlagContinuationEndHeaders Flag = 0x4
 )
 
+func (f Flag) Has(flag Flag) bool {
+	return f&flag != 0
+}
+
 // Setting represents the id and value pair of an HTTP/2 setting.
 // See [Setting Format].
 //
@@ -242,6 +246,8 @@
 	return f.hdr
 }
 
+func (f *WindowUpdateFrame) Free() {}
+
 // ContinuationFrame is the representation of a [CONTINUATION Frame]. The
 // CONTINUATION frame is used to continue a sequence of header block fragments.
 //

internal/transport/grpchttp2/http2bridge.go

@@ -0,0 +1,214 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpchttp2
+
+import (
+	"io"
+
+	"golang.org/x/net/http2"
+	"golang.org/x/net/http2/hpack"
+	"google.golang.org/grpc"
+)
+
+const (
+	initHeaderTableSize = 4096
+	maxFrameLen         = 16384
+)
+
+type HTTP2FramerBridge struct {
+	framer *http2.Framer
+	buf    [maxFrameLen]byte
+	pool   grpc.SharedBufferPool
+}
+
+func NewHTTP2FramerBridge(w io.Writer, r io.Reader, maxHeaderListSize uint32) *HTTP2FramerBridge {
+	fr := &HTTP2FramerBridge{
+		framer: http2.NewFramer(w, r),
+		pool:   grpc.NewSharedBufferPool(),
+	}
+
+	fr.framer.SetReuseFrames()
+	fr.framer.MaxHeaderListSize = maxHeaderListSize
+	fr.framer.ReadMetaHeaders = (hpack.NewDecoder(initHeaderTableSize, nil))
+
+	return fr
+}
+
+func (fr *HTTP2FramerBridge) ReadFrame() (Frame, error) {
+	f, err := fr.framer.ReadFrame()
+	if err != nil {
+		return nil, err
+	}
+
+	h := f.Header()
+	hdr := &FrameHeader{
+		Size:     h.Length,
+		Type:     FrameType(h.Type),
+		Flags:    Flag(h.Flags),
+		StreamID: h.StreamID,
+	}
+
+	switch f := f.(type) {
+	case *http2.DataFrame:
+		buf := fr.pool.Get(int(hdr.Size))
+		copy(buf, f.Data())
+		df := &DataFrame{
+			hdr:  hdr,
+			Data: buf,
+		}
+		df.free = func() {
+			fr.pool.Put(&buf)
+			df.Data = nil
+		}
+		return df, nil
+	case *http2.HeadersFrame:
+		buf := fr.pool.Get(int(hdr.Size))
+		copy(buf, f.HeaderBlockFragment())
+		hf := &HeadersFrame{
+			hdr:      hdr,
+			HdrBlock: buf,
+		}
+		hf.free = func() {
+			fr.pool.Put(&buf)
+			hf.HdrBlock = nil
+		}
+		return hf, nil
+	case *http2.RSTStreamFrame:
+		return &RSTStreamFrame{
+			hdr:  hdr,
+			Code: ErrCode(f.ErrCode),
+		}, nil
+	case *http2.SettingsFrame:
+		buf := make([]Setting, 0, f.NumSettings())
+		f.ForeachSetting(func(s http2.Setting) error {
+			buf = append(buf, Setting{
+				ID:    SettingID(s.ID),
+				Value: s.Val,
+			})
+			return nil
+		})
+		sf := &SettingsFrame{
+			hdr:      hdr,
+			Settings: buf,
+		}
+		return sf, nil
+	case *http2.PingFrame:
+		buf := fr.pool.Get(int(hdr.Size))
+		copy(buf, f.Data[:])
+		pf := &PingFrame{
+			hdr:  hdr,
+			Data: buf,
+		}
+		pf.free = func() {
+			fr.pool.Put(&buf)
+			pf.Data = nil
+		}
+		return pf, nil
+	case *http2.GoAwayFrame:
+		buf := fr.pool.Get(int(hdr.Size - 8))
+		copy(buf, f.DebugData())
+		gf := &GoAwayFrame{
+			hdr:          hdr,
+			DebugData:    buf,
+			Code:         ErrCode(f.ErrCode),
+			LastStreamID: f.LastStreamID,
+		}
+		gf.free = func() {
+			fr.pool.Put(&buf)
+			gf.DebugData = nil
+		}
+		return gf, nil
+	case *http2.WindowUpdateFrame:
+		return &WindowUpdateFrame{
+			hdr: hdr,
+			Inc: f.Increment,
+		}, nil
+	case *http2.ContinuationFrame:
+		buf := fr.pool.Get(int(hdr.Size))
+		copy(buf, f.HeaderBlockFragment())
+		return &ContinuationFrame{
+			hdr:      hdr,
+			HdrBlock: buf,
+		}, nil
+	case *http2.MetaHeadersFrame:
+		return &MetaHeadersFrame{
+			hdr:    hdr,
+			Fields: f.Fields,
+		}, nil
+	}
+
+	return nil, connError(ErrCodeProtocol)
+}
+
+func (fr *HTTP2FramerBridge) WriteData(streamID uint32, endStream bool, data ...[]byte) error {
+	off := 0
+
+	for _, s := range data {
+		off += copy(fr.buf[off:], s)
+	}
+
+	return fr.framer.WriteData(streamID, endStream, fr.buf[:off])
+}
+
+func (fr *HTTP2FramerBridge) WriteHeaders(streamID uint32, endStream, endHeaders bool, headerBlock []byte) error {
+	p := http2.HeadersFrameParam{
+		StreamID:      streamID,
+		EndStream:     endStream,
+		EndHeaders:    endHeaders,
+		BlockFragment: headerBlock,
+	}
+
+	return fr.framer.WriteHeaders(p)
+}
+
+func (fr *HTTP2FramerBridge) WriteRSTStream(streamID uint32, code ErrCode) error {
+	return fr.framer.WriteRSTStream(streamID, http2.ErrCode(code))
+}
+
+func (fr *HTTP2FramerBridge) WriteSettings(settings ...Setting) error {
+	ss := make([]http2.Setting, 0, len(settings))
+	for _, s := range settings {
+		ss = append(ss, http2.Setting{
+			ID:  http2.SettingID(s.ID),
+			Val: s.Value,
+		})
+	}
+
+	return fr.framer.WriteSettings(ss...)
+}
+
+func (fr *HTTP2FramerBridge) WriteSettingsAck() error {
+	return fr.framer.WriteSettingsAck()
+}
+
+func (fr *HTTP2FramerBridge) WritePing(ack bool, data [8]byte) error {
+	return fr.framer.WritePing(ack, data)
+}
+
+func (fr *HTTP2FramerBridge) WriteGoAway(maxStreamID uint32, code ErrCode, debugData []byte) error {
+	return fr.framer.WriteGoAway(maxStreamID, http2.ErrCode(code), debugData)
+}
+
+func (fr *HTTP2FramerBridge) WriteWindowUpdate(streamID, inc uint32) error {
+	return fr.framer.WriteWindowUpdate(streamID, inc)
+}
+
+func (fr *HTTP2FramerBridge) WriteContinuation(streamID uint32, endHeaders bool, headerBlock []byte) error {
+	return fr.framer.WriteContinuation(streamID, endHeaders, headerBlock)
+}