54 lines
1.1 KiB
Go
54 lines
1.1 KiB
Go
package gexec
|
|
|
|
import (
|
|
"io"
|
|
"sync"
|
|
)
|
|
|
|
/*
|
|
PrefixedWriter wraps an io.Writer, emiting the passed in prefix at the beginning of each new line.
|
|
This can be useful when running multiple gexec.Sessions concurrently - you can prefix the log output of each
|
|
session by passing in a PrefixedWriter:
|
|
|
|
gexec.Start(cmd, NewPrefixedWriter("[my-cmd] ", GinkgoWriter), NewPrefixedWriter("[my-cmd] ", GinkgoWriter))
|
|
*/
|
|
type PrefixedWriter struct {
|
|
prefix []byte
|
|
writer io.Writer
|
|
lock *sync.Mutex
|
|
atStartOfLine bool
|
|
}
|
|
|
|
func NewPrefixedWriter(prefix string, writer io.Writer) *PrefixedWriter {
|
|
return &PrefixedWriter{
|
|
prefix: []byte(prefix),
|
|
writer: writer,
|
|
lock: &sync.Mutex{},
|
|
atStartOfLine: true,
|
|
}
|
|
}
|
|
|
|
func (w *PrefixedWriter) Write(b []byte) (int, error) {
|
|
w.lock.Lock()
|
|
defer w.lock.Unlock()
|
|
|
|
toWrite := []byte{}
|
|
|
|
for _, c := range b {
|
|
if w.atStartOfLine {
|
|
toWrite = append(toWrite, w.prefix...)
|
|
}
|
|
|
|
toWrite = append(toWrite, c)
|
|
|
|
w.atStartOfLine = c == '\n'
|
|
}
|
|
|
|
_, err := w.writer.Write(toWrite)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
return len(b), nil
|
|
}
|