SRB2/libs/libopenmpt/inc/libopenmpt/libopenmpt_stream_callbacks_file.h
2019-05-23 22:05:28 -04:00

132 lines
2.9 KiB
C

/*
* libopenmpt_stream_callbacks_file.h
* ----------------------------------
* Purpose: libopenmpt public c interface
* Notes : (currently none)
* Authors: OpenMPT Devs
* The OpenMPT source code is released under the BSD license. Read LICENSE for more details.
*/
#ifndef LIBOPENMPT_STREAM_CALLBACKS_FILE_H
#define LIBOPENMPT_STREAM_CALLBACKS_FILE_H
#include "libopenmpt.h"
#include <limits.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#ifdef _MSC_VER
#include <wchar.h> /* off_t */
#endif
/*! \addtogroup libopenmpt_c
* @{
*/
#ifdef __cplusplus
extern "C" {
#endif
/* This stuff has to be in a header file because of possibly different MSVC CRTs which cause problems for FILE * crossing CRT boundaries. */
static size_t openmpt_stream_file_read_func( void * stream, void * dst, size_t bytes ) {
FILE * f = 0;
size_t retval = 0;
f = (FILE*)stream;
if ( !f ) {
return 0;
}
retval = fread( dst, 1, bytes, f );
if ( retval <= 0 ) {
return 0;
}
return retval;
}
static int openmpt_stream_file_seek_func( void * stream, int64_t offset, int whence ) {
FILE * f = 0;
int fwhence = 0;
f = (FILE*)stream;
if ( !f ) {
return -1;
}
switch ( whence ) {
#if defined(SEEK_SET)
case OPENMPT_STREAM_SEEK_SET:
fwhence = SEEK_SET;
break;
#endif
#if defined(SEEK_CUR)
case OPENMPT_STREAM_SEEK_CUR:
fwhence = SEEK_CUR;
break;
#endif
#if defined(SEEK_END)
case OPENMPT_STREAM_SEEK_END:
fwhence = SEEK_END;
break;
#endif
default:
return -1;
break;
}
#if defined(_MSC_VER)
return _fseeki64( f, offset, fwhence ) ? -1 : 0;
#elif defined(_POSIX_SOURCE) && (_POSIX_SOURCE == 1)
return fseeko( f, offset, fwhence ) ? -1 : 0;
#else
return fseek( f, offset, fwhence ) ? -1 : 0;
#endif
}
static int64_t openmpt_stream_file_tell_func( void * stream ) {
FILE * f = 0;
int64_t retval = 0;
f = (FILE*)stream;
if ( !f ) {
return -1;
}
#if defined(_MSC_VER)
retval = _ftelli64( f );
#elif defined(_POSIX_SOURCE) && (_POSIX_SOURCE == 1)
retval = ftello( f );
#else
retval = ftell( f );
#endif
if ( retval < 0 ) {
return -1;
}
return retval;
}
/*! \brief Provide openmpt_stream_callbacks for standard C FILE objects
*
* Fills openmpt_stream_callbacks suitable for passing a standard C FILE object as a stream parameter to functions doing file input/output.
*
* \remarks The stream argument must be passed as `(void*)(FILE*)file`.
* \sa \ref libopenmpt_c_fileio
* \sa openmpt_stream_callbacks
* \sa openmpt_could_open_probability2
* \sa openmpt_probe_file_header_from_stream
* \sa openmpt_module_create2
*/
static openmpt_stream_callbacks openmpt_stream_get_file_callbacks(void) {
openmpt_stream_callbacks retval;
memset( &retval, 0, sizeof( openmpt_stream_callbacks ) );
retval.read = openmpt_stream_file_read_func;
retval.seek = openmpt_stream_file_seek_func;
retval.tell = openmpt_stream_file_tell_func;
return retval;
}
#ifdef __cplusplus
}
#endif
/*!
* @}
*/
#endif /* LIBOPENMPT_STREAM_CALLBACKS_FILE_H */