mirror of
https://github.com/cwinfo/matterbridge.git
synced 2024-11-22 20:40:27 +00:00
86 lines
2.4 KiB
Go
86 lines
2.4 KiB
Go
/*
|
|
* MinIO Go Library for Amazon S3 Compatible Cloud Storage
|
|
* Copyright 2015-2017 MinIO, Inc.
|
|
*
|
|
* 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 minio
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
)
|
|
|
|
// hookReader hooks additional reader in the source stream. It is
|
|
// useful for making progress bars. Second reader is appropriately
|
|
// notified about the exact number of bytes read from the primary
|
|
// source on each Read operation.
|
|
type hookReader struct {
|
|
source io.Reader
|
|
hook io.Reader
|
|
}
|
|
|
|
// Seek implements io.Seeker. Seeks source first, and if necessary
|
|
// seeks hook if Seek method is appropriately found.
|
|
func (hr *hookReader) Seek(offset int64, whence int) (n int64, err error) {
|
|
// Verify for source has embedded Seeker, use it.
|
|
sourceSeeker, ok := hr.source.(io.Seeker)
|
|
if ok {
|
|
n, err = sourceSeeker.Seek(offset, whence)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
}
|
|
|
|
// Verify if hook has embedded Seeker, use it.
|
|
hookSeeker, ok := hr.hook.(io.Seeker)
|
|
if ok {
|
|
var m int64
|
|
m, err = hookSeeker.Seek(offset, whence)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
if n != m {
|
|
return 0, fmt.Errorf("hook seeker seeked %d bytes, expected source %d bytes", m, n)
|
|
}
|
|
}
|
|
return n, nil
|
|
}
|
|
|
|
// Read implements io.Reader. Always reads from the source, the return
|
|
// value 'n' number of bytes are reported through the hook. Returns
|
|
// error for all non io.EOF conditions.
|
|
func (hr *hookReader) Read(b []byte) (n int, err error) {
|
|
n, err = hr.source.Read(b)
|
|
if err != nil && err != io.EOF {
|
|
return n, err
|
|
}
|
|
// Progress the hook with the total read bytes from the source.
|
|
if _, herr := hr.hook.Read(b[:n]); herr != nil {
|
|
if herr != io.EOF {
|
|
return n, herr
|
|
}
|
|
}
|
|
return n, err
|
|
}
|
|
|
|
// newHook returns a io.ReadSeeker which implements hookReader that
|
|
// reports the data read from the source to the hook.
|
|
func newHook(source, hook io.Reader) io.Reader {
|
|
if hook == nil {
|
|
return source
|
|
}
|
|
return &hookReader{source, hook}
|
|
}
|