github.com/cloudwego/kitex@v0.9.0/pkg/remote/trans/nphttp2/grpc/framer.go (about)

     1  /*
     2   * Copyright 2022 CloudWeGo Authors
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  package grpc
    18  
    19  import (
    20  	"io"
    21  	"net"
    22  
    23  	"github.com/cloudwego/netpoll"
    24  	"golang.org/x/net/http2/hpack"
    25  
    26  	"github.com/cloudwego/kitex/pkg/remote/trans/nphttp2/grpc/grpcframe"
    27  )
    28  
    29  type framer struct {
    30  	*grpcframe.Framer
    31  	reader netpoll.Reader
    32  	writer *bufWriter
    33  }
    34  
    35  func newFramer(conn net.Conn, writeBufferSize, readBufferSize, maxHeaderListSize uint32) *framer {
    36  	var r netpoll.Reader
    37  	if npConn, ok := conn.(interface{ Reader() netpoll.Reader }); ok {
    38  		r = npConn.Reader()
    39  	} else {
    40  		r = netpoll.NewReader(conn)
    41  	}
    42  	w := newBufWriter(conn, int(writeBufferSize))
    43  	fr := &framer{
    44  		reader: r,
    45  		writer: w,
    46  		Framer: grpcframe.NewFramer(w, r),
    47  	}
    48  	fr.SetMaxReadFrameSize(http2MaxFrameLen)
    49  	// Opt-in to Frame reuse API on framer to reduce garbage.
    50  	// Frames aren't safe to read from after a subsequent call to ReadFrame.
    51  	fr.SetReuseFrames()
    52  	fr.MaxHeaderListSize = maxHeaderListSize
    53  	fr.ReadMetaHeaders = hpack.NewDecoder(http2InitHeaderTableSize, nil)
    54  	return fr
    55  }
    56  
    57  type bufWriter struct {
    58  	writer    io.Writer
    59  	buf       []byte
    60  	offset    int
    61  	batchSize int
    62  	err       error
    63  }
    64  
    65  func newBufWriter(writer io.Writer, batchSize int) *bufWriter {
    66  	return &bufWriter{
    67  		buf:       make([]byte, batchSize*2),
    68  		batchSize: batchSize,
    69  		writer:    writer,
    70  	}
    71  }
    72  
    73  func (w *bufWriter) Write(b []byte) (n int, err error) {
    74  	if w.err != nil {
    75  		return 0, w.err
    76  	}
    77  	if w.batchSize == 0 { // buffer has been disabled.
    78  		return w.writer.Write(b)
    79  	}
    80  	for len(b) > 0 {
    81  		nn := copy(w.buf[w.offset:], b)
    82  		b = b[nn:]
    83  		w.offset += nn
    84  		n += nn
    85  		if w.offset >= w.batchSize {
    86  			err = w.Flush()
    87  		}
    88  	}
    89  	return n, err
    90  }
    91  
    92  func (w *bufWriter) Flush() error {
    93  	if w.err != nil {
    94  		return w.err
    95  	}
    96  	if w.offset == 0 {
    97  		return nil
    98  	}
    99  	_, w.err = w.writer.Write(w.buf[:w.offset])
   100  	w.offset = 0
   101  	return w.err
   102  }