mirror of
https://github.com/rocky-linux/peridot.git
synced 2024-12-05 02:56:26 +00:00
138 lines
3.7 KiB
Go
138 lines
3.7 KiB
Go
|
/*
|
||
|
Copyright 2015 The Kubernetes 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 streaming implements encoder and decoder for streams
|
||
|
// of runtime.Objects over io.Writer/Readers.
|
||
|
package streaming
|
||
|
|
||
|
import (
|
||
|
"bytes"
|
||
|
"fmt"
|
||
|
"io"
|
||
|
|
||
|
"k8s.io/apimachinery/pkg/runtime"
|
||
|
"k8s.io/apimachinery/pkg/runtime/schema"
|
||
|
)
|
||
|
|
||
|
// Encoder is a runtime.Encoder on a stream.
|
||
|
type Encoder interface {
|
||
|
// Encode will write the provided object to the stream or return an error. It obeys the same
|
||
|
// contract as runtime.VersionedEncoder.
|
||
|
Encode(obj runtime.Object) error
|
||
|
}
|
||
|
|
||
|
// Decoder is a runtime.Decoder from a stream.
|
||
|
type Decoder interface {
|
||
|
// Decode will return io.EOF when no more objects are available.
|
||
|
Decode(defaults *schema.GroupVersionKind, into runtime.Object) (runtime.Object, *schema.GroupVersionKind, error)
|
||
|
// Close closes the underlying stream.
|
||
|
Close() error
|
||
|
}
|
||
|
|
||
|
// Serializer is a factory for creating encoders and decoders that work over streams.
|
||
|
type Serializer interface {
|
||
|
NewEncoder(w io.Writer) Encoder
|
||
|
NewDecoder(r io.ReadCloser) Decoder
|
||
|
}
|
||
|
|
||
|
type decoder struct {
|
||
|
reader io.ReadCloser
|
||
|
decoder runtime.Decoder
|
||
|
buf []byte
|
||
|
maxBytes int
|
||
|
resetRead bool
|
||
|
}
|
||
|
|
||
|
// NewDecoder creates a streaming decoder that reads object chunks from r and decodes them with d.
|
||
|
// The reader is expected to return ErrShortRead if the provided buffer is not large enough to read
|
||
|
// an entire object.
|
||
|
func NewDecoder(r io.ReadCloser, d runtime.Decoder) Decoder {
|
||
|
return &decoder{
|
||
|
reader: r,
|
||
|
decoder: d,
|
||
|
buf: make([]byte, 1024),
|
||
|
maxBytes: 16 * 1024 * 1024,
|
||
|
}
|
||
|
}
|
||
|
|
||
|
var ErrObjectTooLarge = fmt.Errorf("object to decode was longer than maximum allowed size")
|
||
|
|
||
|
// Decode reads the next object from the stream and decodes it.
|
||
|
func (d *decoder) Decode(defaults *schema.GroupVersionKind, into runtime.Object) (runtime.Object, *schema.GroupVersionKind, error) {
|
||
|
base := 0
|
||
|
for {
|
||
|
n, err := d.reader.Read(d.buf[base:])
|
||
|
if err == io.ErrShortBuffer {
|
||
|
if n == 0 {
|
||
|
return nil, nil, fmt.Errorf("got short buffer with n=0, base=%d, cap=%d", base, cap(d.buf))
|
||
|
}
|
||
|
if d.resetRead {
|
||
|
continue
|
||
|
}
|
||
|
// double the buffer size up to maxBytes
|
||
|
if len(d.buf) < d.maxBytes {
|
||
|
base += n
|
||
|
d.buf = append(d.buf, make([]byte, len(d.buf))...)
|
||
|
continue
|
||
|
}
|
||
|
// must read the rest of the frame (until we stop getting ErrShortBuffer)
|
||
|
d.resetRead = true
|
||
|
base = 0
|
||
|
return nil, nil, ErrObjectTooLarge
|
||
|
}
|
||
|
if err != nil {
|
||
|
return nil, nil, err
|
||
|
}
|
||
|
if d.resetRead {
|
||
|
// now that we have drained the large read, continue
|
||
|
d.resetRead = false
|
||
|
continue
|
||
|
}
|
||
|
base += n
|
||
|
break
|
||
|
}
|
||
|
return d.decoder.Decode(d.buf[:base], defaults, into)
|
||
|
}
|
||
|
|
||
|
func (d *decoder) Close() error {
|
||
|
return d.reader.Close()
|
||
|
}
|
||
|
|
||
|
type encoder struct {
|
||
|
writer io.Writer
|
||
|
encoder runtime.Encoder
|
||
|
buf *bytes.Buffer
|
||
|
}
|
||
|
|
||
|
// NewEncoder returns a new streaming encoder.
|
||
|
func NewEncoder(w io.Writer, e runtime.Encoder) Encoder {
|
||
|
return &encoder{
|
||
|
writer: w,
|
||
|
encoder: e,
|
||
|
buf: &bytes.Buffer{},
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// Encode writes the provided object to the nested writer.
|
||
|
func (e *encoder) Encode(obj runtime.Object) error {
|
||
|
if err := e.encoder.Encode(obj, e.buf); err != nil {
|
||
|
return err
|
||
|
}
|
||
|
_, err := e.writer.Write(e.buf.Bytes())
|
||
|
e.buf.Reset()
|
||
|
return err
|
||
|
}
|