containerd/pkg/transfer/streaming/writer.go
Derek McGowan adfaeeff0d
Add binary stream functionality and helpers
Signed-off-by: Derek McGowan <derek@mcg.dev>
2022-11-30 12:56:53 -08:00

131 lines
3.1 KiB
Go

/*
Copyright The containerd 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
import (
"context"
"errors"
"io"
"sync/atomic"
transferapi "github.com/containerd/containerd/api/types/transfer"
"github.com/containerd/containerd/log"
"github.com/containerd/containerd/pkg/streaming"
"github.com/containerd/typeurl"
)
func WriteByteStream(ctx context.Context, stream streaming.Stream) io.WriteCloser {
wbs := &writeByteStream{
ctx: ctx,
stream: stream,
updated: make(chan struct{}, 1),
}
go func() {
for {
select {
case <-ctx.Done():
return
default:
}
any, err := stream.Recv()
if err != nil {
if !errors.Is(err, io.EOF) && !errors.Is(err, context.Canceled) {
log.G(ctx).WithError(err).Error("send byte stream ended without EOF")
}
return
}
i, err := typeurl.UnmarshalAny(any)
if err != nil {
log.G(ctx).WithError(err).Error("failed to unmarshal stream object")
continue
}
switch v := i.(type) {
case *transferapi.WindowUpdate:
atomic.AddInt32(&wbs.remaining, v.Update)
select {
case <-ctx.Done():
return
case wbs.updated <- struct{}{}:
default:
// Don't block if no writes are waiting
}
default:
log.G(ctx).Errorf("unexpected stream object of type %T", i)
}
}
}()
return wbs
}
type writeByteStream struct {
ctx context.Context
stream streaming.Stream
remaining int32
updated chan struct{}
}
func (wbs *writeByteStream) Write(p []byte) (n int, err error) {
for len(p) > 0 {
remaining := atomic.LoadInt32(&wbs.remaining)
if remaining == 0 {
// Don't wait for window update since there are remaining
select {
case <-wbs.ctx.Done():
// TODO: Send error message on stream before close to allow remote side to return error
err = io.ErrShortWrite
return
case <-wbs.updated:
continue
}
}
var max int32 = maxRead
if max > int32(len(p)) {
max = int32(len(p))
}
if max > remaining {
max = remaining
}
// TODO: continue
//remaining = remaining - int32(n)
data := &transferapi.Data{
Data: p[:max],
}
var any typeurl.Any
any, err = typeurl.MarshalAny(data)
if err != nil {
log.G(wbs.ctx).WithError(err).Errorf("failed to marshal data for send")
// TODO: Send error message on stream before close to allow remote side to return error
return
}
if err = wbs.stream.Send(any); err != nil {
log.G(wbs.ctx).WithError(err).Errorf("send failed")
return
}
n += int(max)
p = p[max:]
atomic.AddInt32(&wbs.remaining, -1*max)
}
return
}
func (wbs *writeByteStream) Close() error {
return wbs.stream.Close()
}