1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2018 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
38extern "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 */
52typedef 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
153extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file,
154 const char *mode);
155
156#ifdef HAVE_STDIO_H
157extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp,
158 SDL_bool autoclose);
159#else
160extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(void * fp,
161 SDL_bool autoclose);
162#endif
163
164extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);
165extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem,
166 int size);
167
168/* @} *//* RWFrom functions */
169
170
171extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void);
172extern 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 * \name Read/write macros
180 *
181 * Macros to easily read and write from an SDL_RWops structure.
182 */
183/* @{ */
184#define SDL_RWsize(ctx) (ctx)->size(ctx)
185#define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence)
186#define SDL_RWtell(ctx) (ctx)->seek(ctx, 0, RW_SEEK_CUR)
187#define SDL_RWread(ctx, ptr, size, n) (ctx)->read(ctx, ptr, size, n)
188#define SDL_RWwrite(ctx, ptr, size, n) (ctx)->write(ctx, ptr, size, n)
189#define SDL_RWclose(ctx) (ctx)->close(ctx)
190/* @} *//* Read/write macros */
191
192
193/**
194 * Load all the data from an SDL data stream.
195 *
196 * The data is allocated with a zero byte at the end (null terminated)
197 *
198 * If \c datasize is not NULL, it is filled with the size of the data read.
199 *
200 * If \c freesrc is non-zero, the stream will be closed after being read.
201 *
202 * The data should be freed with SDL_free().
203 *
204 * \return the data, or NULL if there was an error.
205 */
206extern DECLSPEC void *SDLCALL SDL_LoadFile_RW(SDL_RWops * src, size_t *datasize,
207 int freesrc);
208
209/**
210 * Load an entire file.
211 *
212 * Convenience macro.
213 */
214#define SDL_LoadFile(file, datasize) SDL_LoadFile_RW(SDL_RWFromFile(file, "rb"), datasize, 1)
215
216/**
217 * \name Read endian functions
218 *
219 * Read an item of the specified endianness and return in native format.
220 */
221/* @{ */
222extern DECLSPEC Uint8 SDLCALL SDL_ReadU8(SDL_RWops * src);
223extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src);
224extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src);
225extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src);
226extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src);
227extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src);
228extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src);
229/* @} *//* Read endian functions */
230
231/**
232 * \name Write endian functions
233 *
234 * Write an item of native format to the specified endianness.
235 */
236/* @{ */
237extern DECLSPEC size_t SDLCALL SDL_WriteU8(SDL_RWops * dst, Uint8 value);
238extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);
239extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);
240extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);
241extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);
242extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);
243extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);
244/* @} *//* Write endian functions */
245
246/* Ends C function definitions when using C++ */
247#ifdef __cplusplus
248}
249#endif
250#include "close_code.h"
251
252#endif /* SDL_rwops_h_ */
253
254/* vi: set ts=4 sw=4 expandtab: */
255