51 lines
1009 B
Go
51 lines
1009 B
Go
package buflog
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import (
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"bytes"
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"strings"
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"sync"
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)
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// BufLog implements a simple log buffer that can be supplied to a std
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// log instance. It stores logs up to N lines.
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type BufLog struct {
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maxLines int
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buf *bytes.Buffer
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lines []string
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sync.RWMutex
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}
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// New returns a new log buffer that stores up to maxLines lines.
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func New(maxLines int) *BufLog {
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return &BufLog{
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maxLines: maxLines,
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buf: &bytes.Buffer{},
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lines: make([]string, 0, maxLines),
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}
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}
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// Write writes a log item to the buffer maintaining maxLines capacity
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// using LIFO.
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func (bu *BufLog) Write(b []byte) (n int, err error) {
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bu.Lock()
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if len(bu.lines) >= bu.maxLines {
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bu.lines[0] = ""
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bu.lines = bu.lines[1:len(bu.lines)]
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}
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bu.lines = append(bu.lines, strings.TrimSpace(string(b)))
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bu.Unlock()
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return len(b), nil
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}
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// Lines returns the log lines.
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func (bu *BufLog) Lines() []string {
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bu.RLock()
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defer bu.RUnlock()
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out := make([]string, len(bu.lines))
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copy(out[:], bu.lines[:])
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return out
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}
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