99 lines
2.1 KiB
Go
99 lines
2.1 KiB
Go
/*
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* Copyright (c) 2014 by Farsight Security, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package framestream
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import (
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"bufio"
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"encoding/binary"
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"io"
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)
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type EncoderOptions struct {
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ContentType []byte
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Bidirectional bool
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}
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type Encoder struct {
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writer *bufio.Writer
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reader *bufio.Reader
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opt EncoderOptions
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buf []byte
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}
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func NewEncoder(w io.Writer, opt *EncoderOptions) (enc *Encoder, err error) {
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if opt == nil {
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opt = &EncoderOptions{}
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}
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enc = &Encoder{
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writer: bufio.NewWriter(w),
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opt: *opt,
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}
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if opt.Bidirectional {
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r, ok := w.(io.Reader)
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if !ok {
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return nil, ErrType
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}
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enc.reader = bufio.NewReader(r)
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ready := ControlReady
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ready.SetContentType(opt.ContentType)
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if err = ready.EncodeFlush(enc.writer); err != nil {
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return
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}
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var accept ControlFrame
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if err = accept.DecodeTypeEscape(enc.reader, CONTROL_ACCEPT); err != nil {
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return
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}
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if !accept.MatchContentType(opt.ContentType) {
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return nil, ErrContentTypeMismatch
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}
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}
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// Write the start control frame.
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start := ControlStart
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start.SetContentType(opt.ContentType)
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err = start.Encode(enc.writer)
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if err != nil {
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return
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}
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return
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}
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func (enc *Encoder) Close() (err error) {
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err = ControlStop.EncodeFlush(enc.writer)
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if err != nil || !enc.opt.Bidirectional {
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return
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}
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var finish ControlFrame
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return finish.DecodeTypeEscape(enc.reader, CONTROL_FINISH)
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}
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func (enc *Encoder) Write(frame []byte) (n int, err error) {
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err = binary.Write(enc.writer, binary.BigEndian, uint32(len(frame)))
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if err != nil {
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return
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}
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return enc.writer.Write(frame)
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}
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func (enc *Encoder) Flush() error {
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return enc.writer.Flush()
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}
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