cog/Frameworks/OpenMPT.old/OpenMPT/libopenmpt/libopenmpt_stream_callbacks...

102 lines
2.2 KiB
C

/*
* libopenmpt_stream_callbacks_fd.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_FD_H
#define LIBOPENMPT_STREAM_CALLBACKS_FD_H
#include "libopenmpt.h"
#ifdef _MSC_VER
#include <io.h>
#endif
#include <limits.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#ifndef _MSC_VER
#include <unistd.h>
#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 fd crossing CRT boundaries. */
static size_t openmpt_stream_fd_read_func( void * stream, void * dst, size_t bytes ) {
int fd = 0;
#if defined(_MSC_VER)
size_t retval = 0;
int to_read = 0;
int ret_read = 0;
#else
ssize_t retval = 0;
#endif
fd = (int)(uintptr_t)stream;
if ( fd < 0 ) {
return 0;
}
#if defined(_MSC_VER)
retval = 0;
while ( bytes > 0 ) {
to_read = 0;
if ( bytes < (size_t)INT_MAX ) {
to_read = (int)bytes;
} else {
to_read = INT_MAX;
}
ret_read = _read( fd, dst, to_read );
if ( ret_read <= 0 ) {
return retval;
}
bytes -= ret_read;
retval += ret_read;
}
#else
retval = read( fd, dst, bytes );
#endif
if ( retval <= 0 ) {
return 0;
}
return retval;
}
/*! \brief Provide openmpt_stream_callbacks for standard POSIX file descriptors
*
* Fills openmpt_stream_callbacks suitable for passing a POSIX filer descriptor as a stream parameter to functions doing file input/output.
*
* \remarks The stream argument must be passed as `(void*)(uintptr_t)(int)fd`.
* \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_fd_callbacks(void) {
openmpt_stream_callbacks retval;
memset( &retval, 0, sizeof( openmpt_stream_callbacks ) );
retval.read = openmpt_stream_fd_read_func;
return retval;
}
#ifdef __cplusplus
}
#endif
/*!
* @}
*/
#endif /* LIBOPENMPT_STREAM_CALLBACKS_FD_H */