compose/pkg/utils/writer.go

63 lines
1.5 KiB
Go

/*
Copyright 2020 Docker Compose CLI authors
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package utils
import (
"bytes"
"io"
)
// GetWriter creates an io.Writer that will actually split by line and format by LogConsumer
func GetWriter(consumer func(string)) io.WriteCloser {
return &splitWriter{
buffer: bytes.Buffer{},
consumer: consumer,
}
}
type splitWriter struct {
buffer bytes.Buffer
consumer func(string)
}
// Write implements io.Writer. joins all input, splits on the separator and yields each chunk
func (s *splitWriter) Write(b []byte) (int, error) {
n, err := s.buffer.Write(b)
if err != nil {
return n, err
}
for {
b = s.buffer.Bytes()
index := bytes.Index(b, []byte{'\n'})
if index < 0 {
break
}
line := s.buffer.Next(index + 1)
s.consumer(string(line[:len(line)-1]))
}
return n, nil
}
func (s *splitWriter) Close() error {
b := s.buffer.Bytes()
if len(b) == 0 {
return nil
}
s.consumer(string(b))
return nil
}