1 /* 2 SDL - Simple DirectMedia Layer 3 Copyright (C) 1997-2006 Sam Lantinga 4 5 This library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 This library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with this library; if not, write to the Free Software 17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 18 19 Sam Lantinga 20 slouken (at) libsdl.org 21 */ 22 #include "SDL_config.h" 23 24 /* This file provides a general interface for SDL to read and write 25 data sources. It can easily be extended to files, memory, etc. 26 */ 27 28 #include "SDL_endian.h" 29 #include "SDL_rwops.h" 30 31 32 #if defined(__WIN32__) && !defined(__SYMBIAN32__) 33 34 /* Functions to read/write Win32 API file pointers */ 35 /* Will not use it on WinCE because stdio is buffered, it means 36 faster, and all stdio functions anyway are embedded in coredll.dll - 37 the main wince dll*/ 38 39 #define WINDOWS_LEAN_AND_MEAN 40 #include <windows.h> 41 42 #ifndef INVALID_SET_FILE_POINTER 43 #define INVALID_SET_FILE_POINTER 0xFFFFFFFF 44 #endif 45 46 #define READAHEAD_BUFFER_SIZE 1024 47 48 static int SDLCALL win32_file_open(SDL_RWops *context, const char *filename, const char *mode) 49 { 50 #ifndef _WIN32_WCE 51 UINT old_error_mode; 52 #endif 53 HANDLE h; 54 DWORD r_right, w_right; 55 DWORD must_exist, truncate; 56 int a_mode; 57 58 if (!context) 59 return -1; /* failed (invalid call) */ 60 61 context->hidden.win32io.h = INVALID_HANDLE_VALUE; /* mark this as unusable */ 62 context->hidden.win32io.buffer.data = NULL; 63 context->hidden.win32io.buffer.size = 0; 64 context->hidden.win32io.buffer.left = 0; 65 66 /* "r" = reading, file must exist */ 67 /* "w" = writing, truncate existing, file may not exist */ 68 /* "r+"= reading or writing, file must exist */ 69 /* "a" = writing, append file may not exist */ 70 /* "a+"= append + read, file may not exist */ 71 /* "w+" = read, write, truncate. file may not exist */ 72 73 must_exist = ( SDL_strchr(mode,'r') != NULL ) ? OPEN_EXISTING : 0; 74 truncate = ( SDL_strchr(mode,'w') != NULL ) ? CREATE_ALWAYS : 0; 75 r_right = ( SDL_strchr(mode,'+') != NULL || must_exist ) ? GENERIC_READ : 0; 76 a_mode = ( SDL_strchr(mode,'a') != NULL ) ? OPEN_ALWAYS : 0; 77 w_right = ( a_mode || SDL_strchr(mode,'+') || truncate ) ? GENERIC_WRITE : 0; 78 79 if (!r_right && !w_right) /* inconsistent mode */ 80 return -1; /* failed (invalid call) */ 81 82 context->hidden.win32io.buffer.data = (char *)SDL_malloc(READAHEAD_BUFFER_SIZE); 83 if (!context->hidden.win32io.buffer.data) { 84 SDL_OutOfMemory(); 85 return -1; 86 } 87 88 #ifdef _WIN32_WCE 89 { 90 size_t size = SDL_strlen(filename)+1; 91 wchar_t *filenameW = SDL_stack_alloc(wchar_t, size); 92 93 if ( MultiByteToWideChar(CP_UTF8, 0, filename, -1, filenameW, size) == 0 ) { 94 SDL_stack_free(filenameW); 95 SDL_free(context->hidden.win32io.buffer.data); 96 context->hidden.win32io.buffer.data = NULL; 97 SDL_SetError("Unable to convert filename to Unicode"); 98 return -1; 99 } 100 h = CreateFile(filenameW, (w_right|r_right), (w_right)? 0 : FILE_SHARE_READ, 101 NULL, (must_exist|truncate|a_mode), FILE_ATTRIBUTE_NORMAL,NULL); 102 SDL_stack_free(filenameW); 103 } 104 #else 105 /* Do not open a dialog box if failure */ 106 old_error_mode = SetErrorMode(SEM_NOOPENFILEERRORBOX|SEM_FAILCRITICALERRORS); 107 108 h = CreateFile(filename, (w_right|r_right), (w_right)? 0 : FILE_SHARE_READ, 109 NULL, (must_exist|truncate|a_mode), FILE_ATTRIBUTE_NORMAL,NULL); 110 111 /* restore old behaviour */ 112 SetErrorMode(old_error_mode); 113 #endif /* _WIN32_WCE */ 114 115 if (h==INVALID_HANDLE_VALUE) { 116 SDL_free(context->hidden.win32io.buffer.data); 117 context->hidden.win32io.buffer.data = NULL; 118 SDL_SetError("Couldn't open %s",filename); 119 return -2; /* failed (CreateFile) */ 120 } 121 context->hidden.win32io.h = h; 122 context->hidden.win32io.append = a_mode; 123 124 return 0; /* ok */ 125 } 126 static int SDLCALL win32_file_seek(SDL_RWops *context, int offset, int whence) 127 { 128 DWORD win32whence; 129 int file_pos; 130 131 if (!context || context->hidden.win32io.h == INVALID_HANDLE_VALUE) { 132 SDL_SetError("win32_file_seek: invalid context/file not opened"); 133 return -1; 134 } 135 136 /* FIXME: We may be able to satisfy the seek within buffered data */ 137 if (whence == RW_SEEK_CUR && context->hidden.win32io.buffer.left) { 138 offset -= context->hidden.win32io.buffer.left; 139 } 140 context->hidden.win32io.buffer.left = 0; 141 142 switch (whence) { 143 case RW_SEEK_SET: 144 win32whence = FILE_BEGIN; break; 145 case RW_SEEK_CUR: 146 win32whence = FILE_CURRENT; break; 147 case RW_SEEK_END: 148 win32whence = FILE_END; break; 149 default: 150 SDL_SetError("win32_file_seek: Unknown value for 'whence'"); 151 return -1; 152 } 153 154 file_pos = SetFilePointer(context->hidden.win32io.h,offset,NULL,win32whence); 155 156 if ( file_pos != INVALID_SET_FILE_POINTER ) 157 return file_pos; /* success */ 158 159 SDL_Error(SDL_EFSEEK); 160 return -1; /* error */ 161 } 162 static int SDLCALL win32_file_read(SDL_RWops *context, void *ptr, int size, int maxnum) 163 { 164 int total_need; 165 int total_read = 0; 166 int read_ahead; 167 DWORD byte_read; 168 169 total_need = size*maxnum; 170 171 if (!context || context->hidden.win32io.h == INVALID_HANDLE_VALUE || total_need<=0 || !size) 172 return 0; 173 174 if (context->hidden.win32io.buffer.left > 0) { 175 void *data = (char *)context->hidden.win32io.buffer.data + 176 context->hidden.win32io.buffer.size - 177 context->hidden.win32io.buffer.left; 178 read_ahead = SDL_min(total_need, context->hidden.win32io.buffer.left); 179 SDL_memcpy(ptr, data, read_ahead); 180 context->hidden.win32io.buffer.left -= read_ahead; 181 182 if (read_ahead == total_need) { 183 return maxnum; 184 } 185 ptr = (char *)ptr + read_ahead; 186 total_need -= read_ahead; 187 total_read += read_ahead; 188 } 189 190 if (total_need < READAHEAD_BUFFER_SIZE) { 191 if (!ReadFile(context->hidden.win32io.h,context->hidden.win32io.buffer.data,READAHEAD_BUFFER_SIZE,&byte_read,NULL)) { 192 SDL_Error(SDL_EFREAD); 193 return 0; 194 } 195 read_ahead = SDL_min(total_need, (int)byte_read); 196 SDL_memcpy(ptr, context->hidden.win32io.buffer.data, read_ahead); 197 context->hidden.win32io.buffer.size = byte_read; 198 context->hidden.win32io.buffer.left = byte_read-read_ahead; 199 total_read += read_ahead; 200 } else { 201 if (!ReadFile(context->hidden.win32io.h,ptr,total_need,&byte_read,NULL)) { 202 SDL_Error(SDL_EFREAD); 203 return 0; 204 } 205 total_read += byte_read; 206 } 207 return (total_read/size); 208 } 209 static int SDLCALL win32_file_write(SDL_RWops *context, const void *ptr, int size, int num) 210 { 211 212 int total_bytes; 213 DWORD byte_written,nwritten; 214 215 total_bytes = size*num; 216 217 if (!context || context->hidden.win32io.h==INVALID_HANDLE_VALUE || total_bytes<=0 || !size) 218 return 0; 219 220 if (context->hidden.win32io.buffer.left) { 221 SetFilePointer(context->hidden.win32io.h,-context->hidden.win32io.buffer.left,NULL,FILE_CURRENT); 222 context->hidden.win32io.buffer.left = 0; 223 } 224 225 /* if in append mode, we must go to the EOF before write */ 226 if (context->hidden.win32io.append) { 227 if ( SetFilePointer(context->hidden.win32io.h,0L,NULL,FILE_END) == INVALID_SET_FILE_POINTER ) { 228 SDL_Error(SDL_EFWRITE); 229 return 0; 230 } 231 } 232 233 if (!WriteFile(context->hidden.win32io.h,ptr,total_bytes,&byte_written,NULL)) { 234 SDL_Error(SDL_EFWRITE); 235 return 0; 236 } 237 238 nwritten = byte_written/size; 239 return nwritten; 240 } 241 static int SDLCALL win32_file_close(SDL_RWops *context) 242 { 243 244 if ( context ) { 245 if (context->hidden.win32io.h != INVALID_HANDLE_VALUE) { 246 CloseHandle(context->hidden.win32io.h); 247 context->hidden.win32io.h = INVALID_HANDLE_VALUE; /* to be sure */ 248 } 249 if (context->hidden.win32io.buffer.data) { 250 SDL_free(context->hidden.win32io.buffer.data); 251 context->hidden.win32io.buffer.data = NULL; 252 } 253 SDL_FreeRW(context); 254 } 255 return(0); 256 } 257 #endif /* __WIN32__ */ 258 259 #ifdef HAVE_STDIO_H 260 261 /* Functions to read/write stdio file pointers */ 262 263 static int SDLCALL stdio_seek(SDL_RWops *context, int offset, int whence) 264 { 265 if ( fseek(context->hidden.stdio.fp, offset, whence) == 0 ) { 266 return(ftell(context->hidden.stdio.fp)); 267 } else { 268 SDL_Error(SDL_EFSEEK); 269 return(-1); 270 } 271 } 272 static int SDLCALL stdio_read(SDL_RWops *context, void *ptr, int size, int maxnum) 273 { 274 size_t nread; 275 276 nread = fread(ptr, size, maxnum, context->hidden.stdio.fp); 277 if ( nread == 0 && ferror(context->hidden.stdio.fp) ) { 278 SDL_Error(SDL_EFREAD); 279 } 280 return(nread); 281 } 282 static int SDLCALL stdio_write(SDL_RWops *context, const void *ptr, int size, int num) 283 { 284 size_t nwrote; 285 286 nwrote = fwrite(ptr, size, num, context->hidden.stdio.fp); 287 if ( nwrote == 0 && ferror(context->hidden.stdio.fp) ) { 288 SDL_Error(SDL_EFWRITE); 289 } 290 return(nwrote); 291 } 292 static int SDLCALL stdio_close(SDL_RWops *context) 293 { 294 if ( context ) { 295 if ( context->hidden.stdio.autoclose ) { 296 /* WARNING: Check the return value here! */ 297 fclose(context->hidden.stdio.fp); 298 } 299 SDL_FreeRW(context); 300 } 301 return(0); 302 } 303 #endif /* !HAVE_STDIO_H */ 304 305 /* Functions to read/write memory pointers */ 306 307 static int SDLCALL mem_seek(SDL_RWops *context, int offset, int whence) 308 { 309 Uint8 *newpos; 310 311 switch (whence) { 312 case RW_SEEK_SET: 313 newpos = context->hidden.mem.base+offset; 314 break; 315 case RW_SEEK_CUR: 316 newpos = context->hidden.mem.here+offset; 317 break; 318 case RW_SEEK_END: 319 newpos = context->hidden.mem.stop+offset; 320 break; 321 default: 322 SDL_SetError("Unknown value for 'whence'"); 323 return(-1); 324 } 325 if ( newpos < context->hidden.mem.base ) { 326 newpos = context->hidden.mem.base; 327 } 328 if ( newpos > context->hidden.mem.stop ) { 329 newpos = context->hidden.mem.stop; 330 } 331 context->hidden.mem.here = newpos; 332 return(context->hidden.mem.here-context->hidden.mem.base); 333 } 334 static int SDLCALL mem_read(SDL_RWops *context, void *ptr, int size, int maxnum) 335 { 336 size_t total_bytes; 337 size_t mem_available; 338 339 total_bytes = (maxnum * size); 340 if ( (maxnum <= 0) || (size <= 0) || ((total_bytes / maxnum) != (size_t) size) ) { 341 return 0; 342 } 343 344 mem_available = (context->hidden.mem.stop - context->hidden.mem.here); 345 if (total_bytes > mem_available) { 346 total_bytes = mem_available; 347 } 348 349 SDL_memcpy(ptr, context->hidden.mem.here, total_bytes); 350 context->hidden.mem.here += total_bytes; 351 352 return (total_bytes / size); 353 } 354 static int SDLCALL mem_write(SDL_RWops *context, const void *ptr, int size, int num) 355 { 356 if ( (context->hidden.mem.here + (num*size)) > context->hidden.mem.stop ) { 357 num = (context->hidden.mem.stop-context->hidden.mem.here)/size; 358 } 359 SDL_memcpy(context->hidden.mem.here, ptr, num*size); 360 context->hidden.mem.here += num*size; 361 return(num); 362 } 363 static int SDLCALL mem_writeconst(SDL_RWops *context, const void *ptr, int size, int num) 364 { 365 SDL_SetError("Can't write to read-only memory"); 366 return(-1); 367 } 368 static int SDLCALL mem_close(SDL_RWops *context) 369 { 370 if ( context ) { 371 SDL_FreeRW(context); 372 } 373 return(0); 374 } 375 376 377 /* Functions to create SDL_RWops structures from various data sources */ 378 379 #ifdef __MACOS__ 380 /* 381 * translate unix-style slash-separated filename to mac-style colon-separated 382 * name; return malloced string 383 */ 384 static char *unix_to_mac(const char *file) 385 { 386 int flen = SDL_strlen(file); 387 char *path = SDL_malloc(flen + 2); 388 const char *src = file; 389 char *dst = path; 390 if(*src == '/') { 391 /* really depends on filesystem layout, hope for the best */ 392 src++; 393 } else { 394 /* Check if this is a MacOS path to begin with */ 395 if(*src != ':') 396 *dst++ = ':'; /* relative paths begin with ':' */ 397 } 398 while(src < file + flen) { 399 const char *end = SDL_strchr(src, '/'); 400 int len; 401 if(!end) 402 end = file + flen; /* last component */ 403 len = end - src; 404 if(len == 0 || (len == 1 && src[0] == '.')) { 405 /* remove repeated slashes and . */ 406 } else { 407 if(len == 2 && src[0] == '.' && src[1] == '.') { 408 /* replace .. with the empty string */ 409 } else { 410 SDL_memcpy(dst, src, len); 411 dst += len; 412 } 413 if(end < file + flen) 414 *dst++ = ':'; 415 } 416 src = end + 1; 417 } 418 *dst++ = '\0'; 419 return path; 420 } 421 #endif /* __MACOS__ */ 422 423 SDL_RWops *SDL_RWFromFile(const char *file, const char *mode) 424 { 425 SDL_RWops *rwops = NULL; 426 #ifdef HAVE_STDIO_H 427 FILE *fp = NULL; 428 #endif 429 if ( !file || !*file || !mode || !*mode ) { 430 SDL_SetError("SDL_RWFromFile(): No file or no mode specified"); 431 return NULL; 432 } 433 434 #if defined(__WIN32__) && !defined(__SYMBIAN32__) 435 rwops = SDL_AllocRW(); 436 if (!rwops) 437 return NULL; /* SDL_SetError already setup by SDL_AllocRW() */ 438 if (win32_file_open(rwops,file,mode) < 0) { 439 SDL_FreeRW(rwops); 440 return NULL; 441 } 442 rwops->seek = win32_file_seek; 443 rwops->read = win32_file_read; 444 rwops->write = win32_file_write; 445 rwops->close = win32_file_close; 446 447 #elif HAVE_STDIO_H 448 449 #ifdef __MACOS__ 450 { 451 char *mpath = unix_to_mac(file); 452 fp = fopen(mpath, mode); 453 SDL_free(mpath); 454 } 455 #else 456 fp = fopen(file, mode); 457 #endif 458 if ( fp == NULL ) { 459 SDL_SetError("Couldn't open %s", file); 460 } else { 461 rwops = SDL_RWFromFP(fp, 1); 462 } 463 #else 464 SDL_SetError("SDL not compiled with stdio support"); 465 #endif /* !HAVE_STDIO_H */ 466 467 return(rwops); 468 } 469 470 #ifdef HAVE_STDIO_H 471 SDL_RWops *SDL_RWFromFP(FILE *fp, int autoclose) 472 { 473 SDL_RWops *rwops = NULL; 474 475 rwops = SDL_AllocRW(); 476 if ( rwops != NULL ) { 477 rwops->seek = stdio_seek; 478 rwops->read = stdio_read; 479 rwops->write = stdio_write; 480 rwops->close = stdio_close; 481 rwops->hidden.stdio.fp = fp; 482 rwops->hidden.stdio.autoclose = autoclose; 483 } 484 return(rwops); 485 } 486 #endif /* HAVE_STDIO_H */ 487 488 SDL_RWops *SDL_RWFromMem(void *mem, int size) 489 { 490 SDL_RWops *rwops; 491 492 rwops = SDL_AllocRW(); 493 if ( rwops != NULL ) { 494 rwops->seek = mem_seek; 495 rwops->read = mem_read; 496 rwops->write = mem_write; 497 rwops->close = mem_close; 498 rwops->hidden.mem.base = (Uint8 *)mem; 499 rwops->hidden.mem.here = rwops->hidden.mem.base; 500 rwops->hidden.mem.stop = rwops->hidden.mem.base+size; 501 } 502 return(rwops); 503 } 504 505 SDL_RWops *SDL_RWFromConstMem(const void *mem, int size) 506 { 507 SDL_RWops *rwops; 508 509 rwops = SDL_AllocRW(); 510 if ( rwops != NULL ) { 511 rwops->seek = mem_seek; 512 rwops->read = mem_read; 513 rwops->write = mem_writeconst; 514 rwops->close = mem_close; 515 rwops->hidden.mem.base = (Uint8 *)mem; 516 rwops->hidden.mem.here = rwops->hidden.mem.base; 517 rwops->hidden.mem.stop = rwops->hidden.mem.base+size; 518 } 519 return(rwops); 520 } 521 522 SDL_RWops *SDL_AllocRW(void) 523 { 524 SDL_RWops *area; 525 526 area = (SDL_RWops *)SDL_malloc(sizeof *area); 527 if ( area == NULL ) { 528 SDL_OutOfMemory(); 529 } 530 return(area); 531 } 532 533 void SDL_FreeRW(SDL_RWops *area) 534 { 535 SDL_free(area); 536 } 537 538 /* Functions for dynamically reading and writing endian-specific values */ 539 540 Uint16 SDL_ReadLE16 (SDL_RWops *src) 541 { 542 Uint16 value; 543 544 SDL_RWread(src, &value, (sizeof value), 1); 545 return(SDL_SwapLE16(value)); 546 } 547 Uint16 SDL_ReadBE16 (SDL_RWops *src) 548 { 549 Uint16 value; 550 551 SDL_RWread(src, &value, (sizeof value), 1); 552 return(SDL_SwapBE16(value)); 553 } 554 Uint32 SDL_ReadLE32 (SDL_RWops *src) 555 { 556 Uint32 value; 557 558 SDL_RWread(src, &value, (sizeof value), 1); 559 return(SDL_SwapLE32(value)); 560 } 561 Uint32 SDL_ReadBE32 (SDL_RWops *src) 562 { 563 Uint32 value; 564 565 SDL_RWread(src, &value, (sizeof value), 1); 566 return(SDL_SwapBE32(value)); 567 } 568 Uint64 SDL_ReadLE64 (SDL_RWops *src) 569 { 570 Uint64 value; 571 572 SDL_RWread(src, &value, (sizeof value), 1); 573 return(SDL_SwapLE64(value)); 574 } 575 Uint64 SDL_ReadBE64 (SDL_RWops *src) 576 { 577 Uint64 value; 578 579 SDL_RWread(src, &value, (sizeof value), 1); 580 return(SDL_SwapBE64(value)); 581 } 582 583 int SDL_WriteLE16 (SDL_RWops *dst, Uint16 value) 584 { 585 value = SDL_SwapLE16(value); 586 return(SDL_RWwrite(dst, &value, (sizeof value), 1)); 587 } 588 int SDL_WriteBE16 (SDL_RWops *dst, Uint16 value) 589 { 590 value = SDL_SwapBE16(value); 591 return(SDL_RWwrite(dst, &value, (sizeof value), 1)); 592 } 593 int SDL_WriteLE32 (SDL_RWops *dst, Uint32 value) 594 { 595 value = SDL_SwapLE32(value); 596 return(SDL_RWwrite(dst, &value, (sizeof value), 1)); 597 } 598 int SDL_WriteBE32 (SDL_RWops *dst, Uint32 value) 599 { 600 value = SDL_SwapBE32(value); 601 return(SDL_RWwrite(dst, &value, (sizeof value), 1)); 602 } 603 int SDL_WriteLE64 (SDL_RWops *dst, Uint64 value) 604 { 605 value = SDL_SwapLE64(value); 606 return(SDL_RWwrite(dst, &value, (sizeof value), 1)); 607 } 608 int SDL_WriteBE64 (SDL_RWops *dst, Uint64 value) 609 { 610 value = SDL_SwapBE64(value); 611 return(SDL_RWwrite(dst, &value, (sizeof value), 1)); 612 } 613
