28e2075280
trunk/talk git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
98 lines
3.9 KiB
C++
98 lines
3.9 KiB
C++
/*
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* libjingle
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* Copyright 2004--2005, Google Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
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* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef TALK_BASE_TRANSFORMADAPTER_H__
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#define TALK_BASE_TRANSFORMADAPTER_H__
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#include "talk/base/stream.h"
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namespace talk_base {
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///////////////////////////////////////////////////////////////////////////////
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class TransformInterface {
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public:
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virtual ~TransformInterface() { }
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// Transform should convert the in_len bytes of input into the out_len-sized
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// output buffer. If flush is true, there will be no more data following
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// input.
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// After the transformation, in_len contains the number of bytes consumed, and
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// out_len contains the number of bytes ready in output.
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// Note: Transform should not return SR_BLOCK, as there is no asynchronous
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// notification available.
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virtual StreamResult Transform(const void * input, size_t * in_len,
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void * output, size_t * out_len,
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bool flush) = 0;
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};
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///////////////////////////////////////////////////////////////////////////////
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// TransformAdapter causes all data passed through to be transformed by the
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// supplied TransformInterface object, which may apply compression, encryption,
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// etc.
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class TransformAdapter : public StreamAdapterInterface {
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public:
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// Note that the transformation is unidirectional, in the direction specified
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// by the constructor. Operations in the opposite direction result in SR_EOS.
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TransformAdapter(StreamInterface * stream,
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TransformInterface * transform,
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bool direction_read);
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virtual ~TransformAdapter();
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virtual StreamResult Read(void * buffer, size_t buffer_len,
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size_t * read, int * error);
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virtual StreamResult Write(const void * data, size_t data_len,
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size_t * written, int * error);
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virtual void Close();
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// Apriori, we can't tell what the transformation does to the stream length.
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virtual bool GetAvailable(size_t* size) const { return false; }
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virtual bool ReserveSize(size_t size) { return true; }
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// Transformations might not be restartable
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virtual bool Rewind() { return false; }
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private:
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enum State { ST_PROCESSING, ST_FLUSHING, ST_COMPLETE, ST_ERROR };
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enum { BUFFER_SIZE = 1024 };
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TransformInterface * transform_;
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bool direction_read_;
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State state_;
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int error_;
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char buffer_[BUFFER_SIZE];
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size_t len_;
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};
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///////////////////////////////////////////////////////////////////////////////
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} // namespace talk_base
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#endif // TALK_BASE_TRANSFORMADAPTER_H__
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