forked from apptainer/singularity
/
buffer.go
48 lines (40 loc) · 1.09 KB
/
buffer.go
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// Copyright (c) 2018, Sylabs Inc. All rights reserved.
// This software is licensed under a 3-clause BSD license. Please consult the
// LICENSE.md file distributed with the sources of this project regarding your
// rights to use or distribute this software.
package copy
import (
"bytes"
"sync"
)
// TerminalBuffer captures the last line displayed on terminal.
type TerminalBuffer struct {
data []byte
mutex sync.Mutex
}
// NewTerminalBuffer returns an instantiated TerminalBuffer.
func NewTerminalBuffer() *TerminalBuffer {
b := &TerminalBuffer{}
b.data = make([]byte, 0)
return b
}
// Write implements the write interface to store last terminal line.
func (b *TerminalBuffer) Write(p []byte) (n int, err error) {
b.mutex.Lock()
defer b.mutex.Unlock()
if bytes.IndexByte(p, '\n') >= 0 {
b.data = nil
} else {
b.data = append(b.data, p...)
}
return len(p), nil
}
// Line returns the last terminal line.
func (b *TerminalBuffer) Line() []byte {
b.mutex.Lock()
defer b.mutex.Unlock()
// return a copy to avoid lock exposure
tmp := make([]byte, len(b.data))
copy(tmp, b.data)
return tmp
}