framework/delibs/destream/deIOStream.h

#ifndef _DEIOSTREAM_H
#define _DEIOSTREAM_H
/*-------------------------------------------------------------------------
 * drawElements Stream Library
 * ---------------------------
 *
 * Copyright 2014 The Android Open Source Project
 *
 * 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.
 *
 *//*!
 * \file
 * \brief Input-output stream abstraction.
 *//*--------------------------------------------------------------------*/

#include "deDefs.h"

DE_BEGIN_EXTERN_C

/* Result of operation on stream */
typedef enum deStreamResult_e
{
	DE_STREAMRESULT_SUCCESS = 0,
	DE_STREAMRESULT_END_OF_STREAM,
	DE_STREAMRESULT_ERROR,

	DE_STREAMRESULT_LAST
} deStreamResult;

typedef enum deStreamStatus_e
{
	DE_STREAMSTATUS_GOOD = 0,
	DE_STREAMSTATUS_ERROR,

	DE_STREAMSTATUS_LAST
} deStreamStatus;

/* Type for pointer to internal stream psecifig data */
typedef void deStreamData;

/* Function types for v_table */
typedef deStreamResult	(*deIOStreamReadFunc)		(deStreamData* stream, void* buf, deInt32 bufSize, deInt32* numRead);
typedef deStreamResult	(*deIOStreamWriteFunc)		(deStreamData* stream, const void* buf, deInt32 bufSize, deInt32* numWritten);
typedef const char*		(*deIOStreamGetErrorFunc)	(deStreamData* stream);
typedef deStreamResult	(*deIOStreamFlushFunc)		(deStreamData* stream);
typedef deStreamResult	(*deIOStreamDeinitFunc)		(deStreamData* stream);
typedef deStreamStatus	(*deIOStreamStatusFunc)		(deStreamData* stream);

/* Virtual table type for specifying stream specifig behaviour */
typedef struct deIOStreamVFTable_s
{
	deIOStreamReadFunc		readFunc;
	deIOStreamWriteFunc		writeFunc;
	deIOStreamGetErrorFunc	getErrorFunc;
	deIOStreamFlushFunc		flushFunc;
	deIOStreamDeinitFunc	deinitFunc;
	deIOStreamStatusFunc	statusFunc;
} deIOStreamVFTable;

/* Generig IOStream struct */
typedef struct deIOStream_s
{
	deStreamData*				streamData;
	const deIOStreamVFTable*	vfTable;
} deIOStream;

DE_INLINE deStreamResult	deIOStream_read			(deIOStream* stream, void* buf, deInt32 bufSize, deInt32* numRead);
DE_INLINE deStreamResult	deIOStream_write		(deIOStream* stream, const void* buf, deInt32 bufSize, deInt32* numWritten);
DE_INLINE const char*		deIOStream_getError		(deIOStream* stream);
DE_INLINE deStreamStatus	deIOStream_getStatus	(deIOStream* stream);
DE_INLINE deStreamResult	deIOStream_flush		(deIOStream* stream);
DE_INLINE deStreamResult	deIOStream_deinit		(deIOStream* stream);



DE_INLINE deStreamResult deIOStream_write (deIOStream* stream, const void* buf, deInt32 bufSize, deInt32* numWritten)
{
	DE_ASSERT(stream);
	DE_ASSERT(stream->vfTable);
	DE_ASSERT(stream->vfTable->writeFunc);

	return stream->vfTable->writeFunc(stream->streamData, buf, bufSize, numWritten);
}

DE_INLINE deStreamResult deIOStream_read (deIOStream* stream, void* buf, deInt32 bufSize, deInt32* numRead)
{
	DE_ASSERT(stream);
	DE_ASSERT(stream->vfTable);
	DE_ASSERT(stream->vfTable->readFunc);

	return stream->vfTable->readFunc(stream->streamData, buf, bufSize, numRead);
}

DE_INLINE const char* deIOStream_getError (deIOStream* stream)
{
	DE_ASSERT(stream);
	DE_ASSERT(stream->vfTable);
	DE_ASSERT(stream->vfTable->getErrorFunc);

	return stream->vfTable->getErrorFunc(stream->streamData);
}

DE_INLINE deStreamResult deIOStream_flush (deIOStream* stream)
{
	DE_ASSERT(stream);
	DE_ASSERT(stream->vfTable);
	DE_ASSERT(stream->vfTable->flushFunc);

	return stream->vfTable->flushFunc(stream->streamData);
}

DE_INLINE deStreamResult deIOStream_deinit (deIOStream* stream)
{
	deStreamResult result = DE_STREAMRESULT_ERROR;
	DE_ASSERT(stream);
	DE_ASSERT(stream->vfTable);
	DE_ASSERT(stream->vfTable->deinitFunc);

	result = stream->vfTable->deinitFunc(stream->streamData);

	stream->vfTable		= DE_NULL;
	stream->streamData	= DE_NULL;

	return result;
}

DE_INLINE deStreamStatus deIOStream_getStatus (deIOStream* stream)
{
	DE_ASSERT(stream);
	DE_ASSERT(stream->vfTable);
	DE_ASSERT(stream->vfTable->statusFunc);

	return stream->vfTable->statusFunc(stream->streamData);
}

DE_END_EXTERN_C

#endif /* _DEIOSTREAM_H */