SDL  2.0
SDL_rwops.h
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2020 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 
94  union
95  {
96 #if defined(__ANDROID__)
97  struct
98  {
99  void *asset;
100  } androidio;
101 #elif defined(__WIN32__)
102  struct
103  {
105  void *h;
106  struct
107  {
108  void *data;
109  size_t size;
110  size_t left;
111  } buffer;
112  } windowsio;
113 #endif
114 
115 #ifdef HAVE_STDIO_H
116  struct
117  {
119  FILE *fp;
120  } stdio;
121 #endif
122  struct
123  {
127  } mem;
128  struct
129  {
130  void *data1;
131  void *data2;
132  } unknown;
133  } hidden;
134 
135 } SDL_RWops;
136 
137 
138 /**
139  * \name RWFrom functions
140  *
141  * Functions to create SDL_RWops structures from various data streams.
142  */
143 /* @{ */
144 
145 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file,
146  const char *mode);
147 
148 #ifdef HAVE_STDIO_H
149 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp,
151 #else
152 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(void * fp,
154 #endif
155 
156 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);
157 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem,
158  int size);
159 
160 /* @} *//* RWFrom functions */
161 
162 
163 extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void);
164 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area);
165 
166 #define RW_SEEK_SET 0 /**< Seek from the beginning of data */
167 #define RW_SEEK_CUR 1 /**< Seek relative to current read point */
168 #define RW_SEEK_END 2 /**< Seek relative to the end of data */
169 
170 /**
171  * Return the size of the file in this rwops, or -1 if unknown
172  */
173 extern DECLSPEC Sint64 SDLCALL SDL_RWsize(SDL_RWops *context);
174 
175 /**
176  * Seek to \c offset relative to \c whence, one of stdio's whence values:
177  * RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END
178  *
179  * \return the final offset in the data stream, or -1 on error.
180  */
181 extern DECLSPEC Sint64 SDLCALL SDL_RWseek(SDL_RWops *context,
182  Sint64 offset, int whence);
183 
184 /**
185  * Return the current offset in the data stream, or -1 on error.
186  */
187 extern DECLSPEC Sint64 SDLCALL SDL_RWtell(SDL_RWops *context);
188 
189 /**
190  * Read up to \c maxnum objects each of size \c size from the data
191  * stream to the area pointed at by \c ptr.
192  *
193  * \return the number of objects read, or 0 at error or end of file.
194  */
195 extern DECLSPEC size_t SDLCALL SDL_RWread(SDL_RWops *context,
196  void *ptr, size_t size, size_t maxnum);
197 
198 /**
199  * Write exactly \c num objects each of size \c size from the area
200  * pointed at by \c ptr to data stream.
201  *
202  * \return the number of objects written, or 0 at error or end of file.
203  */
204 extern DECLSPEC size_t SDLCALL SDL_RWwrite(SDL_RWops *context,
205  const void *ptr, size_t size, size_t num);
206 
207 /**
208  * Close and free an allocated SDL_RWops structure.
209  *
210  * \return 0 if successful or -1 on write error when flushing data.
211  */
212 extern DECLSPEC int SDLCALL SDL_RWclose(SDL_RWops *context);
213 
214 /**
215  * Load all the data from an SDL data stream.
216  *
217  * The data is allocated with a zero byte at the end (null terminated)
218  *
219  * If \c datasize is not NULL, it is filled with the size of the data read.
220  *
221  * If \c freesrc is non-zero, the stream will be closed after being read.
222  *
223  * The data should be freed with SDL_free().
224  *
225  * \return the data, or NULL if there was an error.
226  */
227 extern DECLSPEC void *SDLCALL SDL_LoadFile_RW(SDL_RWops * src, size_t *datasize,
228  int freesrc);
229 
230 /**
231  * Load an entire file.
232  *
233  * The data is allocated with a zero byte at the end (null terminated)
234  *
235  * If \c datasize is not NULL, it is filled with the size of the data read.
236  *
237  * If \c freesrc is non-zero, the stream will be closed after being read.
238  *
239  * The data should be freed with SDL_free().
240  *
241  * \return the data, or NULL if there was an error.
242  */
243 extern DECLSPEC void *SDLCALL SDL_LoadFile(const char *file, size_t *datasize);
244 
245 /**
246  * \name Read endian functions
247  *
248  * Read an item of the specified endianness and return in native format.
249  */
250 /* @{ */
251 extern DECLSPEC Uint8 SDLCALL SDL_ReadU8(SDL_RWops * src);
252 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src);
253 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src);
254 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src);
255 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src);
256 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src);
257 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src);
258 /* @} *//* Read endian functions */
259 
260 /**
261  * \name Write endian functions
262  *
263  * Write an item of native format to the specified endianness.
264  */
265 /* @{ */
266 extern DECLSPEC size_t SDLCALL SDL_WriteU8(SDL_RWops * dst, Uint8 value);
267 extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);
268 extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);
269 extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);
270 extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);
271 extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);
272 extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);
273 /* @} *//* Write endian functions */
274 
275 /* Ends C function definitions when using C++ */
276 #ifdef __cplusplus
277 }
278 #endif
279 #include "close_code.h"
280 
281 #endif /* SDL_rwops_h_ */
282 
283 /* vi: set ts=4 sw=4 expandtab: */
void * SDL_LoadFile(const char *file, size_t *datasize)
Uint32 SDL_ReadBE32(SDL_RWops *src)
FILE * fp
Definition: SDL_rwops.h:119
void * data
Definition: SDL_rwops.h:108
SDL_bool append
Definition: SDL_rwops.h:104
SDL_bool
Definition: SDL_stdinc.h:167
size_t left
Definition: SDL_rwops.h:110
size_t size
Definition: SDL_rwops.h:109
SDL_RWops * SDL_RWFromFP(FILE *fp, SDL_bool autoclose)
struct SDL_RWops::@2::@3::@7 buffer
size_t(* write)(struct SDL_RWops *context, const void *ptr, size_t size, size_t num)
Definition: SDL_rwops.h:83
Uint16 SDL_ReadBE16(SDL_RWops *src)
SDL_RWops * SDL_RWFromConstMem(const void *mem, int size)
Uint8 * stop
Definition: SDL_rwops.h:126
uint32_t Uint32
Definition: SDL_stdinc.h:209
size_t SDL_WriteLE32(SDL_RWops *dst, Uint32 value)
void * h
Definition: SDL_rwops.h:105
void * data2
Definition: SDL_rwops.h:131
void SDL_FreeRW(SDL_RWops *area)
uint64_t Uint64
Definition: SDL_stdinc.h:222
size_t SDL_WriteBE32(SDL_RWops *dst, Uint32 value)
SDL_bool autoclose
Definition: SDL_rwops.h:118
Uint32 type
Definition: SDL_rwops.h:93
size_t SDL_WriteU8(SDL_RWops *dst, Uint8 value)
Sint64(* seek)(struct SDL_RWops *context, Sint64 offset, int whence)
Definition: SDL_rwops.h:65
size_t SDL_RWwrite(SDL_RWops *context, const void *ptr, size_t size, size_t num)
uint16_t Uint16
Definition: SDL_stdinc.h:197
size_t SDL_WriteBE16(SDL_RWops *dst, Uint16 value)
void * SDL_LoadFile_RW(SDL_RWops *src, size_t *datasize, int freesrc)
Sint64 SDL_RWsize(SDL_RWops *context)
Sint64 SDL_RWtell(SDL_RWops *context)
Uint8 * base
Definition: SDL_rwops.h:124
SDL_RWops * SDL_AllocRW(void)
int(* close)(struct SDL_RWops *context)
Definition: SDL_rwops.h:91
Uint16 SDL_ReadLE16(SDL_RWops *src)
int SDL_RWclose(SDL_RWops *context)
struct SDL_RWops::@2::@4 stdio
Uint32 SDL_ReadLE32(SDL_RWops *src)
size_t SDL_WriteBE64(SDL_RWops *dst, Uint64 value)
Sint64(* size)(struct SDL_RWops *context)
Definition: SDL_rwops.h:57
struct SDL_RWops::@2::@5 mem
union SDL_RWops::@2 hidden
Uint8 SDL_ReadU8(SDL_RWops *src)
Sint64 SDL_RWseek(SDL_RWops *context, Sint64 offset, int whence)
struct SDL_RWops::@2::@3 windowsio
size_t(* read)(struct SDL_RWops *context, void *ptr, size_t size, size_t maxnum)
Definition: SDL_rwops.h:74
int64_t Sint64
Definition: SDL_stdinc.h:216
Uint64 SDL_ReadBE64(SDL_RWops *src)
size_t SDL_WriteLE64(SDL_RWops *dst, Uint64 value)
size_t SDL_WriteLE16(SDL_RWops *dst, Uint16 value)
size_t SDL_RWread(SDL_RWops *context, void *ptr, size_t size, size_t maxnum)
SDL_RWops * SDL_RWFromFile(const char *file, const char *mode)
void * data1
Definition: SDL_rwops.h:130
Uint8 * here
Definition: SDL_rwops.h:125
uint8_t Uint8
Definition: SDL_stdinc.h:185
SDL_RWops * SDL_RWFromMem(void *mem, int size)
struct SDL_RWops::@2::@6 unknown
Uint64 SDL_ReadLE64(SDL_RWops *src)
unsigned int size_t