godot/thirdparty/libktx/lib/filestream.c

/* -*- tab-width: 4; -*- */
/* vi: set sw=2 ts=4 expandtab: */

/*
 * Copyright 2010-2020 The Khronos Group Inc.
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @file
 * @~English
 *
 * @brief Implementation of ktxStream for FILE.
 *
 * @author Maksim Kolesin, Under Development
 * @author Georg Kolling, Imagination Technology
 * @author Mark Callow, HI Corporation
 */

#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <string.h>
/* I need these on Linux. Why? */
#define __USE_LARGEFILE
#define __USE_POSIX
#define _POSIX_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>     // For stat.h on Windows
#define __USE_MISC
#include <sys/stat.h>

#include "ktx.h"
#include "ktxint.h"
#include "filestream.h"

// Gotta love Windows :-(
#if defined(_MSC_VER)
  #if defined(_WIN64)
    #define ftello
    #define fseeko
  #else
    #define ftello
    #define fseeko
  #endif
  #define fileno
  #define fstat
  #define stat
  #define S_IFIFO
  #define S_IFSOCK
  typedef unsigned short mode_t;
#endif

#if defined(__MINGW32__)
    #define S_IFSOCK
#endif

#define KTX_FILE_STREAM_MAX

/**
 * @~English
 * @brief Read bytes from a ktxFileStream.
 *
 * @param [in]  str     pointer to the ktxStream from which to read.
 * @param [out] dst     pointer to a block of memory with a size
 *                      of at least @p size bytes, converted to a void*.
 * @param [in,out] count   pointer to total count of bytes to be read.
 *                         On completion set to number of bytes read.
 *
 * @return      KTX_SUCCESS on success, other KTX_* enum values on error.
 *
 * @exception KTX_INVALID_VALUE @p dst is @c NULL or @p src is @c NULL.
 * @exception KTX_FILE_READ_ERROR  an error occurred while reading the file.
 * @exception KTX_FILE_UNEXPECTED_EOF not enough data to satisfy the request.
 */
static
KTX_error_code ktxFileStream_read(ktxStream* str, void* dst, const ktx_size_t count)
{}

/**
 * @~English
 * @brief Skip bytes in a ktxFileStream.
 *
 * @param [in] str           pointer to a ktxStream object.
 * @param [in] count         number of bytes to be skipped.
 *
 * In order to support applications reading from stdin, read characters
 * rather than using seek functions.
 *
 * @return      KTX_SUCCESS on success, other KTX_* enum values on error.
 *
 * @exception KTX_INVALID_VALUE @p str is @c NULL or @p count is less than zero.
 * @exception KTX_INVALID_OPERATION skipping @p count bytes would go beyond EOF.
 * @exception KTX_FILE_READ_ERROR  an error occurred while reading the file.
 * @exception KTX_FILE_UNEXPECTED_EOF not enough data to satisfy the request.
 *                                    @p count is set to the number of bytes
 *                                    skipped.
 */
static
KTX_error_code ktxFileStream_skip(ktxStream* str, const ktx_size_t count)
{}

/**
 * @~English
 * @brief Write bytes to a ktxFileStream.
 *
 * @param [in] str      pointer to the ktxStream that is the destination of the
 *                      write.
 * @param [in] src      pointer to the array of elements to be written,
 *                      converted to a const void*.
 * @param [in] size     size in bytes of each element to be written.
 * @param [in] count    number of elements, each one with a @p size of size
 *                      bytes.
 *
 * @return      KTX_SUCCESS on success, other KTX_* enum values on error.
 *
 * @exception KTX_INVALID_VALUE @p str is @c NULL or @p src is @c NULL.
 * @exception KTX_FILE_OVERFLOW the requested write would caused the file to
 *                              exceed the maximum supported file size.
 * @exception KTX_FILE_WRITE_ERROR a system error occurred while writing the
 *                                 file.
 */
static
KTX_error_code ktxFileStream_write(ktxStream* str, const void *src,
                                   const ktx_size_t size,
                                   const ktx_size_t count)
{}

/**
 * @~English
 * @brief Get the current read/write position in a ktxFileStream.
 *
 * @param [in] str      pointer to the ktxStream to query.
 * @param [in,out] off  pointer to variable to receive the offset value.
 *
 * @return      KTX_SUCCESS on success, other KTX_* enum values on error.
 *
 * @exception KTX_FILE_ISPIPE file descriptor underlying stream is associated
 *                            with a pipe or FIFO so does not have a
 *                            file-position indicator.
 * @exception KTX_INVALID_VALUE @p str or @p pos is @c NULL.
 */
static
KTX_error_code ktxFileStream_getpos(ktxStream* str, ktx_off_t* pos)
{}

/**
 * @~English
 * @brief Set the current read/write position in a ktxFileStream.
 *
 * Offset of 0 is the start of the file. This function operates
 * like Linux > 3.1's @c lseek() when it is passed a @c whence
 * of @c SEEK_DATA as it returns an error if the seek would
 * go beyond the end of the file.
 *
 * @param [in] str    pointer to the ktxStream whose r/w position is to be set.
 * @param [in] off    pointer to the offset value to set.
 *
 * @return      KTX_SUCCESS on success, other KTX_* enum values on error.
 *
 * Throws the same exceptions as ktxFileStream_getsize() for the reasons given
 * there plus the following:
 *
 * @exception KTX_INVALID_VALUE @p str is @c NULL.
 * @exception KTX_INVALID_OPERATION @p pos is > the size of the file or an
 *                                  fseek error occurred.
 */
static
KTX_error_code ktxFileStream_setpos(ktxStream* str, ktx_off_t pos)
{}

/**
 * @~English
 * @brief Get the size of a ktxFileStream in bytes.
 *
 * @param [in] str       pointer to the ktxStream whose size is to be queried.
 * @param [in,out] size  pointer to a variable in which size will be written.
 *
 * @return    KTX_SUCCESS on success, other KTX_* enum values on error.
 *
 * @exception KTX_FILE_OVERFLOW size is too large to be returned in a
 *                              @c ktx_size_t.
 * @exception KTX_FILE_ISPIPE file descriptor underlying stream is associated
 *                            with a pipe or FIFO so does not have a
 *                            file-position indicator.
 * @exception KTX_FILE_READ_ERROR a system error occurred while getting the
 *                                size.
 * @exception KTX_INVALID_VALUE @p str or @p size is @c NULL.
 * @exception KTX_INVALID_OPERATION stream is a tty.
 */
static
KTX_error_code ktxFileStream_getsize(ktxStream* str, ktx_size_t* size)
{}

/**
 * @~English
 * @brief Initialize a ktxFileStream.
 *
 * @param [in] str      pointer to the ktxStream to initialize.
 * @param [in] file     pointer to the underlying FILE object.
 * @param [in] closeFileOnDestruct if not false, stdio file pointer will be closed when ktxStream
 *             is destructed.
 *
 * @return      KTX_SUCCESS on success, KTX_INVALID_VALUE on error.
 *
 * @exception KTX_INVALID_VALUE @p stream is @c NULL or @p file is @c NULL.
 */
KTX_error_code ktxFileStream_construct(ktxStream* str, FILE* file,
                                       ktx_bool_t closeFileOnDestruct)
{}

/**
 * @~English
 * @brief Destruct the stream, potentially closing the underlying FILE.
 *
 * This only closes the underyling FILE if the @c closeOnDestruct parameter to
 * ktxFileStream_construct() was not @c KTX_FALSE.
 *
 * @param [in] str pointer to the ktxStream whose FILE is to potentially
 *             be closed.
 */
void
ktxFileStream_destruct(ktxStream* str)
{}