github.com/vmware/govmomi@v0.43.0/vim25/progress/loger.go (about)

     1  /*
     2  Copyright (c) 2024-2024 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 progress
    18  
    19  import (
    20  	"fmt"
    21  	"io"
    22  	"sync"
    23  	"time"
    24  )
    25  
    26  type LogFunc func(msg string) (int, error)
    27  
    28  type ProgressLogger struct {
    29  	log    LogFunc
    30  	prefix string
    31  
    32  	wg sync.WaitGroup
    33  
    34  	sink chan chan Report
    35  	done chan struct{}
    36  }
    37  
    38  func NewProgressLogger(log LogFunc, prefix string) *ProgressLogger {
    39  	p := &ProgressLogger{
    40  		log:    log,
    41  		prefix: prefix,
    42  
    43  		sink: make(chan chan Report),
    44  		done: make(chan struct{}),
    45  	}
    46  
    47  	p.wg.Add(1)
    48  
    49  	go p.loopA()
    50  
    51  	return p
    52  }
    53  
    54  // loopA runs before Sink() has been called.
    55  func (p *ProgressLogger) loopA() {
    56  	var err error
    57  
    58  	defer p.wg.Done()
    59  
    60  	tick := time.NewTicker(100 * time.Millisecond)
    61  	defer tick.Stop()
    62  
    63  	called := false
    64  
    65  	for stop := false; !stop; {
    66  		select {
    67  		case ch := <-p.sink:
    68  			err = p.loopB(tick, ch)
    69  			stop = true
    70  			called = true
    71  		case <-p.done:
    72  			stop = true
    73  		case <-tick.C:
    74  			line := fmt.Sprintf("\r%s", p.prefix)
    75  			p.log(line)
    76  		}
    77  	}
    78  
    79  	if err != nil && err != io.EOF {
    80  		p.log(fmt.Sprintf("\r%sError: %s\n", p.prefix, err))
    81  	} else if called {
    82  		p.log(fmt.Sprintf("\r%sOK\n", p.prefix))
    83  	}
    84  }
    85  
    86  // loopA runs after Sink() has been called.
    87  func (p *ProgressLogger) loopB(tick *time.Ticker, ch <-chan Report) error {
    88  	var r Report
    89  	var ok bool
    90  	var err error
    91  
    92  	for ok = true; ok; {
    93  		select {
    94  		case r, ok = <-ch:
    95  			if !ok {
    96  				break
    97  			}
    98  			err = r.Error()
    99  		case <-tick.C:
   100  			line := fmt.Sprintf("\r%s", p.prefix)
   101  			if r != nil {
   102  				line += fmt.Sprintf("(%.0f%%", r.Percentage())
   103  				detail := r.Detail()
   104  				if detail != "" {
   105  					line += fmt.Sprintf(", %s", detail)
   106  				}
   107  				line += ")"
   108  			}
   109  			p.log(line)
   110  		}
   111  	}
   112  
   113  	return err
   114  }
   115  
   116  func (p *ProgressLogger) Sink() chan<- Report {
   117  	ch := make(chan Report)
   118  	p.sink <- ch
   119  	return ch
   120  }
   121  
   122  func (p *ProgressLogger) Wait() {
   123  	close(p.done)
   124  	p.wg.Wait()
   125  }