github.com/vmware/govmomi@v0.43.0/object/diagnostic_log.go (about)

     1  /*
     2  Copyright (c) 2015 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 object
    18  
    19  import (
    20  	"context"
    21  	"fmt"
    22  	"io"
    23  	"math"
    24  )
    25  
    26  // DiagnosticLog wraps DiagnosticManager.BrowseLog
    27  type DiagnosticLog struct {
    28  	m DiagnosticManager
    29  
    30  	Key  string
    31  	Host *HostSystem
    32  
    33  	Start int32
    34  }
    35  
    36  // Seek to log position starting at the last nlines of the log
    37  func (l *DiagnosticLog) Seek(ctx context.Context, nlines int32) error {
    38  	h, err := l.m.BrowseLog(ctx, l.Host, l.Key, math.MaxInt32, 0)
    39  	if err != nil {
    40  		return err
    41  	}
    42  
    43  	l.Start = h.LineEnd - nlines
    44  
    45  	return nil
    46  }
    47  
    48  // Copy log starting from l.Start to the given io.Writer
    49  // Returns on error or when end of log is reached.
    50  func (l *DiagnosticLog) Copy(ctx context.Context, w io.Writer) (int, error) {
    51  	const max = 500 // VC max == 500, ESX max == 1000
    52  	written := 0
    53  
    54  	for {
    55  		h, err := l.m.BrowseLog(ctx, l.Host, l.Key, l.Start, max)
    56  		if err != nil {
    57  			return 0, err
    58  		}
    59  
    60  		for _, line := range h.LineText {
    61  			n, err := fmt.Fprintln(w, line)
    62  			written += n
    63  			if err != nil {
    64  				return written, err
    65  			}
    66  		}
    67  
    68  		l.Start += int32(len(h.LineText))
    69  
    70  		if l.Start >= h.LineEnd {
    71  			break
    72  		}
    73  	}
    74  
    75  	return written, nil
    76  }