include/SDL_rwops.h
author Sam Lantinga <slouken@libsdl.org>
Tue, 22 Oct 2019 15:43:58 -0700
changeset 13161 b1e49319ec4c
parent 12799 302904fa669a
permissions -rw-r--r--
Fixed accidental whitespace
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 
    22 /**
    23  *  \file SDL_rwops.h
    24  *
    25  *  This file provides a general interface for SDL to read and write
    26  *  data streams.  It can easily be extended to files, memory, etc.
    27  */
    28 
    29 #ifndef SDL_rwops_h_
    30 #define SDL_rwops_h_
    31 
    32 #include "SDL_stdinc.h"
    33 #include "SDL_error.h"
    34 
    35 #include "begin_code.h"
    36 /* Set up for C function definitions, even when using C++ */
    37 #ifdef __cplusplus
    38 extern "C" {
    39 #endif
    40 
    41 /* RWops Types */
    42 #define SDL_RWOPS_UNKNOWN   0U  /**< Unknown stream type */
    43 #define SDL_RWOPS_WINFILE   1U  /**< Win32 file */
    44 #define SDL_RWOPS_STDFILE   2U  /**< Stdio file */
    45 #define SDL_RWOPS_JNIFILE   3U  /**< Android asset */
    46 #define SDL_RWOPS_MEMORY    4U  /**< Memory stream */
    47 #define SDL_RWOPS_MEMORY_RO 5U  /**< Read-Only memory stream */
    48 
    49 /**
    50  * This is the read/write operation structure -- very basic.
    51  */
    52 typedef struct SDL_RWops
    53 {
    54     /**
    55      *  Return the size of the file in this rwops, or -1 if unknown
    56      */
    57     Sint64 (SDLCALL * size) (struct SDL_RWops * context);
    58 
    59     /**
    60      *  Seek to \c offset relative to \c whence, one of stdio's whence values:
    61      *  RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END
    62      *
    63      *  \return the final offset in the data stream, or -1 on error.
    64      */
    65     Sint64 (SDLCALL * seek) (struct SDL_RWops * context, Sint64 offset,
    66                              int whence);
    67 
    68     /**
    69      *  Read up to \c maxnum objects each of size \c size from the data
    70      *  stream to the area pointed at by \c ptr.
    71      *
    72      *  \return the number of objects read, or 0 at error or end of file.
    73      */
    74     size_t (SDLCALL * read) (struct SDL_RWops * context, void *ptr,
    75                              size_t size, size_t maxnum);
    76 
    77     /**
    78      *  Write exactly \c num objects each of size \c size from the area
    79      *  pointed at by \c ptr to data stream.
    80      *
    81      *  \return the number of objects written, or 0 at error or end of file.
    82      */
    83     size_t (SDLCALL * write) (struct SDL_RWops * context, const void *ptr,
    84                               size_t size, size_t num);
    85 
    86     /**
    87      *  Close and free an allocated SDL_RWops structure.
    88      *
    89      *  \return 0 if successful or -1 on write error when flushing data.
    90      */
    91     int (SDLCALL * close) (struct SDL_RWops * context);
    92 
    93     Uint32 type;
    94     union
    95     {
    96 #if defined(__ANDROID__)
    97         struct
    98         {
    99             void *fileNameRef;
   100             void *inputStreamRef;
   101             void *readableByteChannelRef;
   102             void *readMethod;
   103             void *assetFileDescriptorRef;
   104             long position;
   105             long size;
   106             long offset;
   107             int fd;
   108         } androidio;
   109 #elif defined(__WIN32__)
   110         struct
   111         {
   112             SDL_bool append;
   113             void *h;
   114             struct
   115             {
   116                 void *data;
   117                 size_t size;
   118                 size_t left;
   119             } buffer;
   120         } windowsio;
   121 #endif
   122 
   123 #ifdef HAVE_STDIO_H
   124         struct
   125         {
   126             SDL_bool autoclose;
   127             FILE *fp;
   128         } stdio;
   129 #endif
   130         struct
   131         {
   132             Uint8 *base;
   133             Uint8 *here;
   134             Uint8 *stop;
   135         } mem;
   136         struct
   137         {
   138             void *data1;
   139             void *data2;
   140         } unknown;
   141     } hidden;
   142 
   143 } SDL_RWops;
   144 
   145 
   146 /**
   147  *  \name RWFrom functions
   148  *
   149  *  Functions to create SDL_RWops structures from various data streams.
   150  */
   151 /* @{ */
   152 
   153 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file,
   154                                                   const char *mode);
   155 
   156 #ifdef HAVE_STDIO_H
   157 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp,
   158                                                 SDL_bool autoclose);
   159 #else
   160 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(void * fp,
   161                                                 SDL_bool autoclose);
   162 #endif
   163 
   164 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);
   165 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem,
   166                                                       int size);
   167 
   168 /* @} *//* RWFrom functions */
   169 
   170 
   171 extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void);
   172 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area);
   173 
   174 #define RW_SEEK_SET 0       /**< Seek from the beginning of data */
   175 #define RW_SEEK_CUR 1       /**< Seek relative to current read point */
   176 #define RW_SEEK_END 2       /**< Seek relative to the end of data */
   177 
   178 /**
   179  *  Return the size of the file in this rwops, or -1 if unknown
   180  */
   181 extern DECLSPEC Sint64 SDLCALL SDL_RWsize(SDL_RWops *context);
   182 
   183 /**
   184  *  Seek to \c offset relative to \c whence, one of stdio's whence values:
   185  *  RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END
   186  *
   187  *  \return the final offset in the data stream, or -1 on error.
   188  */
   189 extern DECLSPEC Sint64 SDLCALL SDL_RWseek(SDL_RWops *context,
   190                                           Sint64 offset, int whence);
   191 
   192 /**
   193  *  Return the current offset in the data stream, or -1 on error.
   194  */
   195 extern DECLSPEC Sint64 SDLCALL SDL_RWtell(SDL_RWops *context);
   196 
   197 /**
   198  *  Read up to \c maxnum objects each of size \c size from the data
   199  *  stream to the area pointed at by \c ptr.
   200  *
   201  *  \return the number of objects read, or 0 at error or end of file.
   202  */
   203 extern DECLSPEC size_t SDLCALL SDL_RWread(SDL_RWops *context,
   204                                           void *ptr, size_t size, size_t maxnum);
   205 
   206 /**
   207  *  Write exactly \c num objects each of size \c size from the area
   208  *  pointed at by \c ptr to data stream.
   209  *
   210  *  \return the number of objects written, or 0 at error or end of file.
   211  */
   212 extern DECLSPEC size_t SDLCALL SDL_RWwrite(SDL_RWops *context,
   213                                            const void *ptr, size_t size, size_t num);
   214 
   215 /**
   216  *  Close and free an allocated SDL_RWops structure.
   217  *
   218  *  \return 0 if successful or -1 on write error when flushing data.
   219  */
   220 extern DECLSPEC int SDLCALL SDL_RWclose(SDL_RWops *context);
   221 
   222 /**
   223  *  Load all the data from an SDL data stream.
   224  *
   225  *  The data is allocated with a zero byte at the end (null terminated)
   226  *
   227  *  If \c datasize is not NULL, it is filled with the size of the data read.
   228  *
   229  *  If \c freesrc is non-zero, the stream will be closed after being read.
   230  *
   231  *  The data should be freed with SDL_free().
   232  *
   233  *  \return the data, or NULL if there was an error.
   234  */
   235 extern DECLSPEC void *SDLCALL SDL_LoadFile_RW(SDL_RWops * src, size_t *datasize,
   236                                                     int freesrc);
   237 
   238 /**
   239  *  Load an entire file.
   240  *
   241  *  The data is allocated with a zero byte at the end (null terminated)
   242  *
   243  *  If \c datasize is not NULL, it is filled with the size of the data read.
   244  *
   245  *  If \c freesrc is non-zero, the stream will be closed after being read.
   246  *
   247  *  The data should be freed with SDL_free().
   248  *
   249  *  \return the data, or NULL if there was an error.
   250  */
   251 extern DECLSPEC void *SDLCALL SDL_LoadFile(const char *file, size_t *datasize);
   252 
   253 /**
   254  *  \name Read endian functions
   255  *
   256  *  Read an item of the specified endianness and return in native format.
   257  */
   258 /* @{ */
   259 extern DECLSPEC Uint8 SDLCALL SDL_ReadU8(SDL_RWops * src);
   260 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src);
   261 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src);
   262 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src);
   263 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src);
   264 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src);
   265 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src);
   266 /* @} *//* Read endian functions */
   267 
   268 /**
   269  *  \name Write endian functions
   270  *
   271  *  Write an item of native format to the specified endianness.
   272  */
   273 /* @{ */
   274 extern DECLSPEC size_t SDLCALL SDL_WriteU8(SDL_RWops * dst, Uint8 value);
   275 extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);
   276 extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);
   277 extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);
   278 extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);
   279 extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);
   280 extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);
   281 /* @} *//* Write endian functions */
   282 
   283 /* Ends C function definitions when using C++ */
   284 #ifdef __cplusplus
   285 }
   286 #endif
   287 #include "close_code.h"
   288 
   289 #endif /* SDL_rwops_h_ */
   290 
   291 /* vi: set ts=4 sw=4 expandtab: */