github.com/alejandroesc/spdy@v0.0.0-20200317064415-01a02f0eb389/spdy3/frames/ping.go (about)

     1  // Copyright 2014 Jamie Hall. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package frames
     6  
     7  import (
     8  	"bytes"
     9  	"fmt"
    10  	"io"
    11  
    12  	"github.com/SlyMarbo/spdy/common"
    13  )
    14  
    15  type PING struct {
    16  	PingID uint32
    17  }
    18  
    19  func (frame *PING) Compress(comp common.Compressor) error {
    20  	return nil
    21  }
    22  
    23  func (frame *PING) Decompress(decomp common.Decompressor) error {
    24  	return nil
    25  }
    26  
    27  func (frame *PING) Name() string {
    28  	return "PING"
    29  }
    30  
    31  func (frame *PING) ReadFrom(reader io.Reader) (int64, error) {
    32  	c := common.ReadCounter{R: reader}
    33  	data, err := common.ReadExactly(&c, 12)
    34  	if err != nil {
    35  		return c.N, err
    36  	}
    37  
    38  	err = controlFrameCommonProcessing(data[:5], _PING, 0)
    39  	if err != nil {
    40  		return c.N, err
    41  	}
    42  
    43  	// Get and check length.
    44  	length := int(common.BytesToUint24(data[5:8]))
    45  	if length != 4 {
    46  		return c.N, common.IncorrectDataLength(length, 4)
    47  	}
    48  
    49  	frame.PingID = common.BytesToUint32(data[8:12])
    50  
    51  	return c.N, nil
    52  }
    53  
    54  func (frame *PING) String() string {
    55  	buf := new(bytes.Buffer)
    56  
    57  	buf.WriteString("PING {\n\t")
    58  	buf.WriteString(fmt.Sprintf("Version:              3\n\t"))
    59  	buf.WriteString(fmt.Sprintf("Ping ID:              %d\n}\n", frame.PingID))
    60  
    61  	return buf.String()
    62  }
    63  
    64  func (frame *PING) WriteTo(writer io.Writer) (int64, error) {
    65  	c := common.WriteCounter{W: writer}
    66  	out := make([]byte, 12)
    67  
    68  	out[0] = 128                      // Control bit and Version
    69  	out[1] = 3                        // Version
    70  	out[2] = 0                        // Type
    71  	out[3] = 6                        // Type
    72  	out[4] = 0                        // common.Flags
    73  	out[5] = 0                        // Length
    74  	out[6] = 0                        // Length
    75  	out[7] = 4                        // Length
    76  	out[8] = byte(frame.PingID >> 24) // Ping ID
    77  	out[9] = byte(frame.PingID >> 16) // Ping ID
    78  	out[10] = byte(frame.PingID >> 8) // Ping ID
    79  	out[11] = byte(frame.PingID)      // Ping ID
    80  
    81  	err := common.WriteExactly(&c, out)
    82  	if err != nil {
    83  		return c.N, err
    84  	}
    85  
    86  	return c.N, nil
    87  }