#ifndef PA_STREAM_H#define PA_STREAM_H/* * $Id: pa_stream.h 1097 2006-08-26 08:27:53Z rossb $ * Portable Audio I/O Library * stream interface * * Based on the Open Source API proposed by Ross Bencina * Copyright (c) 1999-2002 Ross Bencina, Phil Burk * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files * (the "Software"), to deal in the Software without restriction, * including without limitation the rights to use, copy, modify, merge, * publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, * subject to the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. *//* * The text above constitutes the entire PortAudio license; however,  * the PortAudio community also makes the following non-binding requests: * * Any person wishing to distribute modifications to the Software is * requested to send the modifications to the original developer so that * they can be incorporated into the canonical version. It is also  * requested that these non-binding requests be included along with the  * license above. *//** @file @ingroup common_src @brief Interface used by pa_front to virtualize functions which operate on streams.*/#include "portaudio.h"#ifdef __cplusplusextern "C"{#endif /* __cplusplus */#define PA_STREAM_MAGIC (0x18273645)/** A structure representing an (abstract) interface to a host API. Contains pointers to functions which implement the interface. All PaStreamInterface functions are guaranteed to be called with a non-null, valid stream parameter.*/typedef struct {    PaError (*Close)( PaStream* stream );    PaError (*Start)( PaStream *stream );    PaError (*Stop)( PaStream *stream );    PaError (*Abort)( PaStream *stream );    PaError (*IsStopped)( PaStream *stream );    PaError (*IsActive)( PaStream *stream );    PaTime (*GetTime)( PaStream *stream );    double (*GetCpuLoad)( PaStream* stream );    PaError (*Read)( PaStream* stream, void *buffer, unsigned long frames );    PaError (*Write)( PaStream* stream, const void *buffer, unsigned long frames );    signed long (*GetReadAvailable)( PaStream* stream );    signed long (*GetWriteAvailable)( PaStream* stream );} PaUtilStreamInterface;/** Initialize the fields of a PaUtilStreamInterface structure.*/void PaUtil_InitializeStreamInterface( PaUtilStreamInterface *streamInterface,    PaError (*Close)( PaStream* ),    PaError (*Start)( PaStream* ),    PaError (*Stop)( PaStream* ),    PaError (*Abort)( PaStream* ),    PaError (*IsStopped)( PaStream* ),    PaError (*IsActive)( PaStream* ),    PaTime (*GetTime)( PaStream* ),    double (*GetCpuLoad)( PaStream* ),    PaError (*Read)( PaStream* stream, void *buffer, unsigned long frames ),    PaError (*Write)( PaStream* stream, const void *buffer, unsigned long frames ),    signed long (*GetReadAvailable)( PaStream* stream ),    signed long (*GetWriteAvailable)( PaStream* stream ) );/** Dummy Read function for use in interfaces to a callback based streams. Pass to the Read parameter of PaUtil_InitializeStreamInterface. @return An error code indicating that the function has no effect because the stream is a callback stream.*/PaError PaUtil_DummyRead( PaStream* stream,                       void *buffer,                       unsigned long frames );/** Dummy Write function for use in an interfaces to callback based streams. Pass to the Write parameter of PaUtil_InitializeStreamInterface. @return An error code indicating that the function has no effect because the stream is a callback stream.*/PaError PaUtil_DummyWrite( PaStream* stream,                       const void *buffer,                       unsigned long frames );/** Dummy GetReadAvailable function for use in interfaces to callback based streams. Pass to the GetReadAvailable parameter of PaUtil_InitializeStreamInterface. @return An error code indicating that the function has no effect because the stream is a callback stream.*/signed long PaUtil_DummyGetReadAvailable( PaStream* stream );/** Dummy GetWriteAvailable function for use in interfaces to callback based streams. Pass to the GetWriteAvailable parameter of PaUtil_InitializeStreamInterface. @return An error code indicating that the function has no effect because the stream is a callback stream.*/signed long PaUtil_DummyGetWriteAvailable( PaStream* stream );/** Dummy GetCpuLoad function for use in an interface to a read/write stream. Pass to the GetCpuLoad parameter of PaUtil_InitializeStreamInterface. @return Returns 0.*/double PaUtil_DummyGetCpuLoad( PaStream* stream );/** Non host specific data for a stream. This data is used by pa_front to forward to the appropriate functions in the streamInterface structure.*/typedef struct PaUtilStreamRepresentation {    unsigned long magic;    /**< set to PA_STREAM_MAGIC */    struct PaUtilStreamRepresentation *nextOpenStream; /**< field used by multi-api code */    PaUtilStreamInterface *streamInterface;    PaStreamCallback *streamCallback;    PaStreamFinishedCallback *streamFinishedCallback;    void *userData;    PaStreamInfo streamInfo;} PaUtilStreamRepresentation;/** Initialize a PaUtilStreamRepresentation structure. @see PaUtil_InitializeStreamRepresentation*/void PaUtil_InitializeStreamRepresentation(        PaUtilStreamRepresentation *streamRepresentation,        PaUtilStreamInterface *streamInterface,        PaStreamCallback *streamCallback,        void *userData );        /** Clean up a PaUtilStreamRepresentation structure previously initialized by a call to PaUtil_InitializeStreamRepresentation. @see PaUtil_InitializeStreamRepresentation*/void PaUtil_TerminateStreamRepresentation( PaUtilStreamRepresentation *streamRepresentation );/** Check that the stream pointer is valid. @return Returns paNoError if the stream pointer appears to be OK, otherwise returns an error indicating the cause of failure.*/PaError PaUtil_ValidateStreamPointer( PaStream *stream );/** Cast an opaque stream pointer into a pointer to a PaUtilStreamRepresentation. @see PaUtilStreamRepresentation*/#define PA_STREAM_REP( stream )\    ((PaUtilStreamRepresentation*) (stream) )/** Cast an opaque stream pointer into a pointer to a PaUtilStreamInterface. @see PaUtilStreamRepresentation, PaUtilStreamInterface*/#define PA_STREAM_INTERFACE( stream )\    PA_STREAM_REP( (stream) )->streamInterface    #ifdef __cplusplus}#endif /* __cplusplus */#endif /* PA_STREAM_H */