github.com/vmware/govmomi@v0.37.2/toolbox/trace_channel.go (about)

     1  /*
     2  Copyright (c) 2017 VMware, Inc. All Rights Reserved.
     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 toolbox
    18  
    19  import (
    20  	"encoding/hex"
    21  	"flag"
    22  	"fmt"
    23  	"io"
    24  	"os"
    25  )
    26  
    27  var (
    28  	Trace = false
    29  
    30  	traceLog io.Writer = os.Stderr
    31  )
    32  
    33  func init() {
    34  	flag.BoolVar(&Trace, "toolbox.trace", Trace, "Enable toolbox trace")
    35  }
    36  
    37  type TraceChannel struct {
    38  	Channel
    39  	log io.Writer
    40  }
    41  
    42  func NewTraceChannel(c Channel) Channel {
    43  	if !Trace {
    44  		return c
    45  	}
    46  
    47  	return &TraceChannel{
    48  		Channel: c,
    49  		log:     traceLog,
    50  	}
    51  }
    52  
    53  func (d *TraceChannel) Start() error {
    54  	err := d.Channel.Start()
    55  
    56  	return err
    57  }
    58  
    59  func (d *TraceChannel) Stop() error {
    60  	err := d.Channel.Stop()
    61  
    62  	return err
    63  }
    64  
    65  func (d *TraceChannel) Send(buf []byte) error {
    66  	if len(buf) > 0 {
    67  		fmt.Fprintf(d.log, "SEND %d...\n%s\n", len(buf), hex.Dump(buf))
    68  	}
    69  
    70  	err := d.Channel.Send(buf)
    71  
    72  	return err
    73  }
    74  
    75  func (d *TraceChannel) Receive() ([]byte, error) {
    76  	buf, err := d.Channel.Receive()
    77  
    78  	if err == nil && len(buf) > 0 {
    79  		fmt.Fprintf(d.log, "RECV %d...\n%s\n", len(buf), hex.Dump(buf))
    80  	}
    81  
    82  	return buf, err
    83  }