1 #if !defined(_FX_JPEG_TURBO_) 2 /* 3 * jmemmgr.c 4 * 5 * Copyright (C) 1991-1997, Thomas G. Lane. 6 * This file is part of the Independent JPEG Group's software. 7 * For conditions of distribution and use, see the accompanying README file. 8 * 9 * This file contains the JPEG system-independent memory management 10 * routines. This code is usable across a wide variety of machines; most 11 * of the system dependencies have been isolated in a separate file. 12 * The major functions provided here are: 13 * * pool-based allocation and freeing of memory; 14 * * policy decisions about how to divide available memory among the 15 * virtual arrays; 16 * * control logic for swapping virtual arrays between main memory and 17 * backing storage. 18 * The separate system-dependent file provides the actual backing-storage 19 * access code, and it contains the policy decision about how much total 20 * main memory to use. 21 * This file is system-dependent in the sense that some of its functions 22 * are unnecessary in some systems. For example, if there is enough virtual 23 * memory so that backing storage will never be used, much of the virtual 24 * array control logic could be removed. (Of course, if you have that much 25 * memory then you shouldn't care about a little bit of unused code...) 26 */ 27 28 #define JPEG_INTERNALS 29 #define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */ 30 #include "jinclude.h" 31 #include "jpeglib.h" 32 #include "jmemsys.h" /* import the system-dependent declarations */ 33 34 #define NO_GETENV /* XYQ: 2007-5-22 Don't use it */ 35 36 #ifndef NO_GETENV 37 #ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */ 38 extern char * getenv JPP((const char * name)); 39 #endif 40 #endif 41 42 43 /* 44 * Some important notes: 45 * The allocation routines provided here must never return NULL. 46 * They should exit to error_exit if unsuccessful. 47 * 48 * It's not a good idea to try to merge the sarray and barray routines, 49 * even though they are textually almost the same, because samples are 50 * usually stored as bytes while coefficients are shorts or ints. Thus, 51 * in machines where byte pointers have a different representation from 52 * word pointers, the resulting machine code could not be the same. 53 */ 54 55 56 /* 57 * Many machines require storage alignment: longs must start on 4-byte 58 * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc() 59 * always returns pointers that are multiples of the worst-case alignment 60 * requirement, and we had better do so too. 61 * There isn't any really portable way to determine the worst-case alignment 62 * requirement. This module assumes that the alignment requirement is 63 * multiples of sizeof(ALIGN_TYPE). 64 * By default, we define ALIGN_TYPE as double. This is necessary on some 65 * workstations (where doubles really do need 8-byte alignment) and will work 66 * fine on nearly everything. If your machine has lesser alignment needs, 67 * you can save a few bytes by making ALIGN_TYPE smaller. 68 * The only place I know of where this will NOT work is certain Macintosh 69 * 680x0 compilers that define double as a 10-byte IEEE extended float. 70 * Doing 10-byte alignment is counterproductive because longwords won't be 71 * aligned well. Put "#define ALIGN_TYPE long" in jconfig.h if you have 72 * such a compiler. 73 */ 74 75 #ifndef ALIGN_TYPE /* so can override from jconfig.h */ 76 #define ALIGN_TYPE double 77 #endif 78 79 80 /* 81 * We allocate objects from "pools", where each pool is gotten with a single 82 * request to jpeg_get_small() or jpeg_get_large(). There is no per-object 83 * overhead within a pool, except for alignment padding. Each pool has a 84 * header with a link to the next pool of the same class. 85 * Small and large pool headers are identical except that the latter's 86 * link pointer must be FAR on 80x86 machines. 87 * Notice that the "real" header fields are union'ed with a dummy ALIGN_TYPE 88 * field. This forces the compiler to make SIZEOF(small_pool_hdr) a multiple 89 * of the alignment requirement of ALIGN_TYPE. 90 */ 91 92 typedef union small_pool_struct * small_pool_ptr; 93 94 typedef union small_pool_struct { 95 struct { 96 small_pool_ptr next; /* next in list of pools */ 97 size_t bytes_used; /* how many bytes already used within pool */ 98 size_t bytes_left; /* bytes still available in this pool */ 99 } hdr; 100 ALIGN_TYPE dummy; /* included in union to ensure alignment */ 101 } small_pool_hdr; 102 103 typedef union large_pool_struct FAR * large_pool_ptr; 104 105 typedef union large_pool_struct { 106 struct { 107 large_pool_ptr next; /* next in list of pools */ 108 size_t bytes_used; /* how many bytes already used within pool */ 109 size_t bytes_left; /* bytes still available in this pool */ 110 } hdr; 111 ALIGN_TYPE dummy; /* included in union to ensure alignment */ 112 } large_pool_hdr; 113 114 115 /* 116 * Here is the full definition of a memory manager object. 117 */ 118 119 typedef struct { 120 struct jpeg_memory_mgr pub; /* public fields */ 121 122 /* Each pool identifier (lifetime class) names a linked list of pools. */ 123 small_pool_ptr small_list[JPOOL_NUMPOOLS]; 124 large_pool_ptr large_list[JPOOL_NUMPOOLS]; 125 126 /* Since we only have one lifetime class of virtual arrays, only one 127 * linked list is necessary (for each datatype). Note that the virtual 128 * array control blocks being linked together are actually stored somewhere 129 * in the small-pool list. 130 */ 131 jvirt_sarray_ptr virt_sarray_list; 132 jvirt_barray_ptr virt_barray_list; 133 134 /* This counts total space obtained from jpeg_get_small/large */ 135 long total_space_allocated; 136 137 /* alloc_sarray and alloc_barray set this value for use by virtual 138 * array routines. 139 */ 140 JDIMENSION last_rowsperchunk; /* from most recent alloc_sarray/barray */ 141 } my_memory_mgr; 142 143 typedef my_memory_mgr * my_mem_ptr; 144 145 146 /* 147 * The control blocks for virtual arrays. 148 * Note that these blocks are allocated in the "small" pool area. 149 * System-dependent info for the associated backing store (if any) is hidden 150 * inside the backing_store_info struct. 151 */ 152 153 struct jvirt_sarray_control { 154 JSAMPARRAY mem_buffer; /* => the in-memory buffer */ 155 JDIMENSION rows_in_array; /* total virtual array height */ 156 JDIMENSION samplesperrow; /* width of array (and of memory buffer) */ 157 JDIMENSION maxaccess; /* max rows accessed by access_virt_sarray */ 158 JDIMENSION rows_in_mem; /* height of memory buffer */ 159 JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */ 160 JDIMENSION cur_start_row; /* first logical row # in the buffer */ 161 JDIMENSION first_undef_row; /* row # of first uninitialized row */ 162 boolean pre_zero; /* pre-zero mode requested? */ 163 boolean dirty; /* do current buffer contents need written? */ 164 boolean b_s_open; /* is backing-store data valid? */ 165 jvirt_sarray_ptr next; /* link to next virtual sarray control block */ 166 backing_store_info b_s_info; /* System-dependent control info */ 167 }; 168 169 struct jvirt_barray_control { 170 JBLOCKARRAY mem_buffer; /* => the in-memory buffer */ 171 JDIMENSION rows_in_array; /* total virtual array height */ 172 JDIMENSION blocksperrow; /* width of array (and of memory buffer) */ 173 JDIMENSION maxaccess; /* max rows accessed by access_virt_barray */ 174 JDIMENSION rows_in_mem; /* height of memory buffer */ 175 JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */ 176 JDIMENSION cur_start_row; /* first logical row # in the buffer */ 177 JDIMENSION first_undef_row; /* row # of first uninitialized row */ 178 boolean pre_zero; /* pre-zero mode requested? */ 179 boolean dirty; /* do current buffer contents need written? */ 180 boolean b_s_open; /* is backing-store data valid? */ 181 jvirt_barray_ptr next; /* link to next virtual barray control block */ 182 backing_store_info b_s_info; /* System-dependent control info */ 183 }; 184 185 186 #ifdef MEM_STATS /* optional extra stuff for statistics */ 187 188 LOCAL(void) 189 print_mem_stats (j_common_ptr cinfo, int pool_id) 190 { 191 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 192 small_pool_ptr shdr_ptr; 193 large_pool_ptr lhdr_ptr; 194 195 /* Since this is only a debugging stub, we can cheat a little by using 196 * fprintf directly rather than going through the trace message code. 197 * This is helpful because message parm array can't handle longs. 198 */ 199 FXSYS_fprintf(stderr, "Freeing pool %d, total space = %ld\n", 200 pool_id, mem->total_space_allocated); 201 202 for (lhdr_ptr = mem->large_list[pool_id]; lhdr_ptr != NULL; 203 lhdr_ptr = lhdr_ptr->hdr.next) { 204 FXSYS_fprintf(stderr, " Large chunk used %ld\n", 205 (long) lhdr_ptr->hdr.bytes_used); 206 } 207 208 for (shdr_ptr = mem->small_list[pool_id]; shdr_ptr != NULL; 209 shdr_ptr = shdr_ptr->hdr.next) { 210 FXSYS_fprintf(stderr, " Small chunk used %ld free %ld\n", 211 (long) shdr_ptr->hdr.bytes_used, 212 (long) shdr_ptr->hdr.bytes_left); 213 } 214 } 215 216 #endif /* MEM_STATS */ 217 218 219 LOCAL(void) 220 out_of_memory (j_common_ptr cinfo, int which) 221 /* Report an out-of-memory error and stop execution */ 222 /* If we compiled MEM_STATS support, report alloc requests before dying */ 223 { 224 #ifdef MEM_STATS 225 cinfo->err->trace_level = 2; /* force self_destruct to report stats */ 226 #endif 227 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, which); 228 } 229 230 231 /* 232 * Allocation of "small" objects. 233 * 234 * For these, we use pooled storage. When a new pool must be created, 235 * we try to get enough space for the current request plus a "slop" factor, 236 * where the slop will be the amount of leftover space in the new pool. 237 * The speed vs. space tradeoff is largely determined by the slop values. 238 * A different slop value is provided for each pool class (lifetime), 239 * and we also distinguish the first pool of a class from later ones. 240 * NOTE: the values given work fairly well on both 16- and 32-bit-int 241 * machines, but may be too small if longs are 64 bits or more. 242 */ 243 244 static const size_t first_pool_slop[JPOOL_NUMPOOLS] = 245 { 246 1600, /* first PERMANENT pool */ 247 16000 /* first IMAGE pool */ 248 }; 249 250 static const size_t extra_pool_slop[JPOOL_NUMPOOLS] = 251 { 252 0, /* additional PERMANENT pools */ 253 5000 /* additional IMAGE pools */ 254 }; 255 256 #define MIN_SLOP 50 /* greater than 0 to avoid futile looping */ 257 258 259 METHODDEF(void *) 260 alloc_small (j_common_ptr cinfo, int pool_id, size_t sizeofobject) 261 /* Allocate a "small" object */ 262 { 263 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 264 small_pool_ptr hdr_ptr, prev_hdr_ptr; 265 char * data_ptr; 266 size_t odd_bytes, min_request, slop; 267 268 /* Check for unsatisfiable request (do now to ensure no overflow below) */ 269 if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(small_pool_hdr))) 270 out_of_memory(cinfo, 1); /* request exceeds malloc's ability */ 271 272 /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */ 273 odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE); 274 if (odd_bytes > 0) 275 sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes; 276 277 /* See if space is available in any existing pool */ 278 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 279 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 280 prev_hdr_ptr = NULL; 281 hdr_ptr = mem->small_list[pool_id]; 282 while (hdr_ptr != NULL) { 283 if (hdr_ptr->hdr.bytes_left >= sizeofobject) 284 break; /* found pool with enough space */ 285 prev_hdr_ptr = hdr_ptr; 286 hdr_ptr = hdr_ptr->hdr.next; 287 } 288 289 /* Time to make a new pool? */ 290 if (hdr_ptr == NULL) { 291 /* min_request is what we need now, slop is what will be leftover */ 292 min_request = sizeofobject + SIZEOF(small_pool_hdr); 293 if (prev_hdr_ptr == NULL) /* first pool in class? */ 294 slop = first_pool_slop[pool_id]; 295 else 296 slop = extra_pool_slop[pool_id]; 297 /* Don't ask for more than MAX_ALLOC_CHUNK */ 298 if (slop > (size_t) (MAX_ALLOC_CHUNK-min_request)) 299 slop = (size_t) (MAX_ALLOC_CHUNK-min_request); 300 /* Try to get space, if fail reduce slop and try again */ 301 for (;;) { 302 hdr_ptr = (small_pool_ptr) jpeg_get_small(cinfo, min_request + slop); 303 if (hdr_ptr != NULL) 304 break; 305 slop /= 2; 306 if (slop < MIN_SLOP) /* give up when it gets real small */ 307 out_of_memory(cinfo, 2); /* jpeg_get_small failed */ 308 } 309 mem->total_space_allocated += min_request + slop; 310 /* Success, initialize the new pool header and add to end of list */ 311 hdr_ptr->hdr.next = NULL; 312 hdr_ptr->hdr.bytes_used = 0; 313 hdr_ptr->hdr.bytes_left = sizeofobject + slop; 314 if (prev_hdr_ptr == NULL) /* first pool in class? */ 315 mem->small_list[pool_id] = hdr_ptr; 316 else 317 prev_hdr_ptr->hdr.next = hdr_ptr; 318 } 319 320 /* OK, allocate the object from the current pool */ 321 data_ptr = (char *) (hdr_ptr + 1); /* point to first data byte in pool */ 322 data_ptr += hdr_ptr->hdr.bytes_used; /* point to place for object */ 323 hdr_ptr->hdr.bytes_used += sizeofobject; 324 hdr_ptr->hdr.bytes_left -= sizeofobject; 325 326 return (void *) data_ptr; 327 } 328 329 330 /* 331 * Allocation of "large" objects. 332 * 333 * The external semantics of these are the same as "small" objects, 334 * except that FAR pointers are used on 80x86. However the pool 335 * management heuristics are quite different. We assume that each 336 * request is large enough that it may as well be passed directly to 337 * jpeg_get_large; the pool management just links everything together 338 * so that we can free it all on demand. 339 * Note: the major use of "large" objects is in JSAMPARRAY and JBLOCKARRAY 340 * structures. The routines that create these structures (see below) 341 * deliberately bunch rows together to ensure a large request size. 342 */ 343 344 METHODDEF(void FAR *) 345 alloc_large (j_common_ptr cinfo, int pool_id, size_t sizeofobject) 346 /* Allocate a "large" object */ 347 { 348 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 349 large_pool_ptr hdr_ptr; 350 size_t odd_bytes; 351 352 /* Check for unsatisfiable request (do now to ensure no overflow below) */ 353 if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr))) 354 out_of_memory(cinfo, 3); /* request exceeds malloc's ability */ 355 356 /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */ 357 odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE); 358 if (odd_bytes > 0) 359 sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes; 360 361 /* Always make a new pool */ 362 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 363 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 364 365 hdr_ptr = (large_pool_ptr) jpeg_get_large(cinfo, sizeofobject + 366 SIZEOF(large_pool_hdr)); 367 if (hdr_ptr == NULL) 368 out_of_memory(cinfo, 4); /* jpeg_get_large failed */ 369 mem->total_space_allocated += sizeofobject + SIZEOF(large_pool_hdr); 370 371 /* Success, initialize the new pool header and add to list */ 372 hdr_ptr->hdr.next = mem->large_list[pool_id]; 373 /* We maintain space counts in each pool header for statistical purposes, 374 * even though they are not needed for allocation. 375 */ 376 hdr_ptr->hdr.bytes_used = sizeofobject; 377 hdr_ptr->hdr.bytes_left = 0; 378 mem->large_list[pool_id] = hdr_ptr; 379 380 return (void FAR *) (hdr_ptr + 1); /* point to first data byte in pool */ 381 } 382 383 384 /* 385 * Creation of 2-D sample arrays. 386 * The pointers are in near heap, the samples themselves in FAR heap. 387 * 388 * To minimize allocation overhead and to allow I/O of large contiguous 389 * blocks, we allocate the sample rows in groups of as many rows as possible 390 * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request. 391 * NB: the virtual array control routines, later in this file, know about 392 * this chunking of rows. The rowsperchunk value is left in the mem manager 393 * object so that it can be saved away if this sarray is the workspace for 394 * a virtual array. 395 */ 396 397 METHODDEF(JSAMPARRAY) 398 alloc_sarray (j_common_ptr cinfo, int pool_id, 399 JDIMENSION samplesperrow, JDIMENSION numrows) 400 /* Allocate a 2-D sample array */ 401 { 402 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 403 JSAMPARRAY result; 404 JSAMPROW workspace; 405 JDIMENSION rowsperchunk, currow, i; 406 long ltemp; 407 408 /* Calculate max # of rows allowed in one allocation chunk */ 409 ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) / 410 ((long) samplesperrow * SIZEOF(JSAMPLE)); 411 if (ltemp <= 0) 412 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 413 if (ltemp < (long) numrows) 414 rowsperchunk = (JDIMENSION) ltemp; 415 else 416 rowsperchunk = numrows; 417 mem->last_rowsperchunk = rowsperchunk; 418 419 /* Get space for row pointers (small object) */ 420 result = (JSAMPARRAY) alloc_small(cinfo, pool_id, 421 (size_t) (numrows * SIZEOF(JSAMPROW))); 422 423 /* Get the rows themselves (large objects) */ 424 currow = 0; 425 while (currow < numrows) { 426 rowsperchunk = MIN(rowsperchunk, numrows - currow); 427 workspace = (JSAMPROW) alloc_large(cinfo, pool_id, 428 (size_t) ((size_t) rowsperchunk * (size_t) samplesperrow 429 * SIZEOF(JSAMPLE))); 430 for (i = rowsperchunk; i > 0; i--) { 431 result[currow++] = workspace; 432 workspace += samplesperrow; 433 } 434 } 435 436 return result; 437 } 438 439 440 /* 441 * Creation of 2-D coefficient-block arrays. 442 * This is essentially the same as the code for sample arrays, above. 443 */ 444 445 METHODDEF(JBLOCKARRAY) 446 alloc_barray (j_common_ptr cinfo, int pool_id, 447 JDIMENSION blocksperrow, JDIMENSION numrows) 448 /* Allocate a 2-D coefficient-block array */ 449 { 450 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 451 JBLOCKARRAY result; 452 JBLOCKROW workspace; 453 JDIMENSION rowsperchunk, currow, i; 454 long ltemp; 455 456 /* Calculate max # of rows allowed in one allocation chunk */ 457 ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) / 458 ((long) blocksperrow * SIZEOF(JBLOCK)); 459 if (ltemp <= 0) 460 ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); 461 if (ltemp < (long) numrows) 462 rowsperchunk = (JDIMENSION) ltemp; 463 else 464 rowsperchunk = numrows; 465 mem->last_rowsperchunk = rowsperchunk; 466 467 /* Get space for row pointers (small object) */ 468 result = (JBLOCKARRAY) alloc_small(cinfo, pool_id, 469 (size_t) (numrows * SIZEOF(JBLOCKROW))); 470 471 /* Get the rows themselves (large objects) */ 472 currow = 0; 473 while (currow < numrows) { 474 rowsperchunk = MIN(rowsperchunk, numrows - currow); 475 workspace = (JBLOCKROW) alloc_large(cinfo, pool_id, 476 (size_t) ((size_t) rowsperchunk * (size_t) blocksperrow 477 * SIZEOF(JBLOCK))); 478 for (i = rowsperchunk; i > 0; i--) { 479 result[currow++] = workspace; 480 workspace += blocksperrow; 481 } 482 } 483 484 return result; 485 } 486 487 488 /* 489 * About virtual array management: 490 * 491 * The above "normal" array routines are only used to allocate strip buffers 492 * (as wide as the image, but just a few rows high). Full-image-sized buffers 493 * are handled as "virtual" arrays. The array is still accessed a strip at a 494 * time, but the memory manager must save the whole array for repeated 495 * accesses. The intended implementation is that there is a strip buffer in 496 * memory (as high as is possible given the desired memory limit), plus a 497 * backing file that holds the rest of the array. 498 * 499 * The request_virt_array routines are told the total size of the image and 500 * the maximum number of rows that will be accessed at once. The in-memory 501 * buffer must be at least as large as the maxaccess value. 502 * 503 * The request routines create control blocks but not the in-memory buffers. 504 * That is postponed until realize_virt_arrays is called. At that time the 505 * total amount of space needed is known (approximately, anyway), so free 506 * memory can be divided up fairly. 507 * 508 * The access_virt_array routines are responsible for making a specific strip 509 * area accessible (after reading or writing the backing file, if necessary). 510 * Note that the access routines are told whether the caller intends to modify 511 * the accessed strip; during a read-only pass this saves having to rewrite 512 * data to disk. The access routines are also responsible for pre-zeroing 513 * any newly accessed rows, if pre-zeroing was requested. 514 * 515 * In current usage, the access requests are usually for nonoverlapping 516 * strips; that is, successive access start_row numbers differ by exactly 517 * num_rows = maxaccess. This means we can get good performance with simple 518 * buffer dump/reload logic, by making the in-memory buffer be a multiple 519 * of the access height; then there will never be accesses across bufferload 520 * boundaries. The code will still work with overlapping access requests, 521 * but it doesn't handle bufferload overlaps very efficiently. 522 */ 523 524 525 METHODDEF(jvirt_sarray_ptr) 526 request_virt_sarray (j_common_ptr cinfo, int pool_id, boolean pre_zero, 527 JDIMENSION samplesperrow, JDIMENSION numrows, 528 JDIMENSION maxaccess) 529 /* Request a virtual 2-D sample array */ 530 { 531 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 532 jvirt_sarray_ptr result; 533 534 /* Only IMAGE-lifetime virtual arrays are currently supported */ 535 if (pool_id != JPOOL_IMAGE) 536 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 537 538 /* get control block */ 539 result = (jvirt_sarray_ptr) alloc_small(cinfo, pool_id, 540 SIZEOF(struct jvirt_sarray_control)); 541 542 result->mem_buffer = NULL; /* marks array not yet realized */ 543 result->rows_in_array = numrows; 544 result->samplesperrow = samplesperrow; 545 result->maxaccess = maxaccess; 546 result->pre_zero = pre_zero; 547 result->b_s_open = FALSE; /* no associated backing-store object */ 548 result->next = mem->virt_sarray_list; /* add to list of virtual arrays */ 549 mem->virt_sarray_list = result; 550 551 return result; 552 } 553 554 555 METHODDEF(jvirt_barray_ptr) 556 request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero, 557 JDIMENSION blocksperrow, JDIMENSION numrows, 558 JDIMENSION maxaccess) 559 /* Request a virtual 2-D coefficient-block array */ 560 { 561 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 562 jvirt_barray_ptr result; 563 564 /* Only IMAGE-lifetime virtual arrays are currently supported */ 565 if (pool_id != JPOOL_IMAGE) 566 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 567 568 /* get control block */ 569 result = (jvirt_barray_ptr) alloc_small(cinfo, pool_id, 570 SIZEOF(struct jvirt_barray_control)); 571 572 result->mem_buffer = NULL; /* marks array not yet realized */ 573 result->rows_in_array = numrows; 574 result->blocksperrow = blocksperrow; 575 result->maxaccess = maxaccess; 576 result->pre_zero = pre_zero; 577 result->b_s_open = FALSE; /* no associated backing-store object */ 578 result->next = mem->virt_barray_list; /* add to list of virtual arrays */ 579 mem->virt_barray_list = result; 580 581 return result; 582 } 583 584 585 METHODDEF(void) 586 realize_virt_arrays (j_common_ptr cinfo) 587 /* Allocate the in-memory buffers for any unrealized virtual arrays */ 588 { 589 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 590 long space_per_minheight, maximum_space, avail_mem; 591 long minheights, max_minheights; 592 jvirt_sarray_ptr sptr; 593 jvirt_barray_ptr bptr; 594 595 /* Compute the minimum space needed (maxaccess rows in each buffer) 596 * and the maximum space needed (full image height in each buffer). 597 * These may be of use to the system-dependent jpeg_mem_available routine. 598 */ 599 space_per_minheight = 0; 600 maximum_space = 0; 601 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 602 if (sptr->mem_buffer == NULL) { /* if not realized yet */ 603 space_per_minheight += (long) sptr->maxaccess * 604 (long) sptr->samplesperrow * SIZEOF(JSAMPLE); 605 maximum_space += (long) sptr->rows_in_array * 606 (long) sptr->samplesperrow * SIZEOF(JSAMPLE); 607 } 608 } 609 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 610 if (bptr->mem_buffer == NULL) { /* if not realized yet */ 611 space_per_minheight += (long) bptr->maxaccess * 612 (long) bptr->blocksperrow * SIZEOF(JBLOCK); 613 maximum_space += (long) bptr->rows_in_array * 614 (long) bptr->blocksperrow * SIZEOF(JBLOCK); 615 } 616 } 617 618 if (space_per_minheight <= 0) 619 return; /* no unrealized arrays, no work */ 620 621 /* Determine amount of memory to actually use; this is system-dependent. */ 622 avail_mem = jpeg_mem_available(cinfo, space_per_minheight, maximum_space, 623 mem->total_space_allocated); 624 625 /* If the maximum space needed is available, make all the buffers full 626 * height; otherwise parcel it out with the same number of minheights 627 * in each buffer. 628 */ 629 if (avail_mem >= maximum_space) 630 max_minheights = 1000000000L; 631 else { 632 max_minheights = avail_mem / space_per_minheight; 633 /* If there doesn't seem to be enough space, try to get the minimum 634 * anyway. This allows a "stub" implementation of jpeg_mem_available(). 635 */ 636 if (max_minheights <= 0) 637 max_minheights = 1; 638 } 639 640 /* Allocate the in-memory buffers and initialize backing store as needed. */ 641 642 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 643 if (sptr->mem_buffer == NULL) { /* if not realized yet */ 644 minheights = ((long) sptr->rows_in_array - 1L) / sptr->maxaccess + 1L; 645 if (minheights <= max_minheights) { 646 /* This buffer fits in memory */ 647 sptr->rows_in_mem = sptr->rows_in_array; 648 } else { 649 /* It doesn't fit in memory, create backing store. */ 650 sptr->rows_in_mem = (JDIMENSION) (max_minheights * sptr->maxaccess); 651 jpeg_open_backing_store(cinfo, & sptr->b_s_info, 652 (long) sptr->rows_in_array * 653 (long) sptr->samplesperrow * 654 (long) SIZEOF(JSAMPLE)); 655 sptr->b_s_open = TRUE; 656 } 657 sptr->mem_buffer = alloc_sarray(cinfo, JPOOL_IMAGE, 658 sptr->samplesperrow, sptr->rows_in_mem); 659 sptr->rowsperchunk = mem->last_rowsperchunk; 660 sptr->cur_start_row = 0; 661 sptr->first_undef_row = 0; 662 sptr->dirty = FALSE; 663 } 664 } 665 666 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 667 if (bptr->mem_buffer == NULL) { /* if not realized yet */ 668 minheights = ((long) bptr->rows_in_array - 1L) / bptr->maxaccess + 1L; 669 if (minheights <= max_minheights) { 670 /* This buffer fits in memory */ 671 bptr->rows_in_mem = bptr->rows_in_array; 672 } else { 673 /* It doesn't fit in memory, create backing store. */ 674 bptr->rows_in_mem = (JDIMENSION) (max_minheights * bptr->maxaccess); 675 jpeg_open_backing_store(cinfo, & bptr->b_s_info, 676 (long) bptr->rows_in_array * 677 (long) bptr->blocksperrow * 678 (long) SIZEOF(JBLOCK)); 679 bptr->b_s_open = TRUE; 680 } 681 bptr->mem_buffer = alloc_barray(cinfo, JPOOL_IMAGE, 682 bptr->blocksperrow, bptr->rows_in_mem); 683 bptr->rowsperchunk = mem->last_rowsperchunk; 684 bptr->cur_start_row = 0; 685 bptr->first_undef_row = 0; 686 bptr->dirty = FALSE; 687 } 688 } 689 } 690 691 692 LOCAL(void) 693 do_sarray_io (j_common_ptr cinfo, jvirt_sarray_ptr ptr, boolean writing) 694 /* Do backing store read or write of a virtual sample array */ 695 { 696 long bytesperrow, file_offset, byte_count, rows, thisrow, i; 697 698 bytesperrow = (long) ptr->samplesperrow * SIZEOF(JSAMPLE); 699 file_offset = ptr->cur_start_row * bytesperrow; 700 /* Loop to read or write each allocation chunk in mem_buffer */ 701 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) { 702 /* One chunk, but check for short chunk at end of buffer */ 703 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i); 704 /* Transfer no more than is currently defined */ 705 thisrow = (long) ptr->cur_start_row + i; 706 rows = MIN(rows, (long) ptr->first_undef_row - thisrow); 707 /* Transfer no more than fits in file */ 708 rows = MIN(rows, (long) ptr->rows_in_array - thisrow); 709 if (rows <= 0) /* this chunk might be past end of file! */ 710 break; 711 byte_count = rows * bytesperrow; 712 if (writing) 713 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, 714 (void FAR *) ptr->mem_buffer[i], 715 file_offset, byte_count); 716 else 717 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, 718 (void FAR *) ptr->mem_buffer[i], 719 file_offset, byte_count); 720 file_offset += byte_count; 721 } 722 } 723 724 725 LOCAL(void) 726 do_barray_io (j_common_ptr cinfo, jvirt_barray_ptr ptr, boolean writing) 727 /* Do backing store read or write of a virtual coefficient-block array */ 728 { 729 long bytesperrow, file_offset, byte_count, rows, thisrow, i; 730 731 bytesperrow = (long) ptr->blocksperrow * SIZEOF(JBLOCK); 732 file_offset = ptr->cur_start_row * bytesperrow; 733 /* Loop to read or write each allocation chunk in mem_buffer */ 734 for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) { 735 /* One chunk, but check for short chunk at end of buffer */ 736 rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i); 737 /* Transfer no more than is currently defined */ 738 thisrow = (long) ptr->cur_start_row + i; 739 rows = MIN(rows, (long) ptr->first_undef_row - thisrow); 740 /* Transfer no more than fits in file */ 741 rows = MIN(rows, (long) ptr->rows_in_array - thisrow); 742 if (rows <= 0) /* this chunk might be past end of file! */ 743 break; 744 byte_count = rows * bytesperrow; 745 if (writing) 746 (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, 747 (void FAR *) ptr->mem_buffer[i], 748 file_offset, byte_count); 749 else 750 (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, 751 (void FAR *) ptr->mem_buffer[i], 752 file_offset, byte_count); 753 file_offset += byte_count; 754 } 755 } 756 757 758 METHODDEF(JSAMPARRAY) 759 access_virt_sarray (j_common_ptr cinfo, jvirt_sarray_ptr ptr, 760 JDIMENSION start_row, JDIMENSION num_rows, 761 boolean writable) 762 /* Access the part of a virtual sample array starting at start_row */ 763 /* and extending for num_rows rows. writable is true if */ 764 /* caller intends to modify the accessed area. */ 765 { 766 JDIMENSION end_row = start_row + num_rows; 767 JDIMENSION undef_row; 768 769 /* debugging check */ 770 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || 771 ptr->mem_buffer == NULL) 772 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 773 774 /* Make the desired part of the virtual array accessible */ 775 if (start_row < ptr->cur_start_row || 776 end_row > ptr->cur_start_row+ptr->rows_in_mem) { 777 if (! ptr->b_s_open) 778 ERREXIT(cinfo, JERR_VIRTUAL_BUG); 779 /* Flush old buffer contents if necessary */ 780 if (ptr->dirty) { 781 do_sarray_io(cinfo, ptr, TRUE); 782 ptr->dirty = FALSE; 783 } 784 /* Decide what part of virtual array to access. 785 * Algorithm: if target address > current window, assume forward scan, 786 * load starting at target address. If target address < current window, 787 * assume backward scan, load so that target area is top of window. 788 * Note that when switching from forward write to forward read, will have 789 * start_row = 0, so the limiting case applies and we load from 0 anyway. 790 */ 791 if (start_row > ptr->cur_start_row) { 792 ptr->cur_start_row = start_row; 793 } else { 794 /* use long arithmetic here to avoid overflow & unsigned problems */ 795 long ltemp; 796 797 ltemp = (long) end_row - (long) ptr->rows_in_mem; 798 if (ltemp < 0) 799 ltemp = 0; /* don't fall off front end of file */ 800 ptr->cur_start_row = (JDIMENSION) ltemp; 801 } 802 /* Read in the selected part of the array. 803 * During the initial write pass, we will do no actual read 804 * because the selected part is all undefined. 805 */ 806 do_sarray_io(cinfo, ptr, FALSE); 807 } 808 /* Ensure the accessed part of the array is defined; prezero if needed. 809 * To improve locality of access, we only prezero the part of the array 810 * that the caller is about to access, not the entire in-memory array. 811 */ 812 if (ptr->first_undef_row < end_row) { 813 if (ptr->first_undef_row < start_row) { 814 if (writable) /* writer skipped over a section of array */ 815 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 816 undef_row = start_row; /* but reader is allowed to read ahead */ 817 } else { 818 undef_row = ptr->first_undef_row; 819 } 820 if (writable) 821 ptr->first_undef_row = end_row; 822 if (ptr->pre_zero) { 823 size_t bytesperrow = (size_t) ptr->samplesperrow * SIZEOF(JSAMPLE); 824 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */ 825 end_row -= ptr->cur_start_row; 826 while (undef_row < end_row) { 827 jzero_far((void FAR *) ptr->mem_buffer[undef_row], bytesperrow); 828 undef_row++; 829 } 830 } else { 831 if (! writable) /* reader looking at undefined data */ 832 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 833 } 834 } 835 /* Flag the buffer dirty if caller will write in it */ 836 if (writable) 837 ptr->dirty = TRUE; 838 /* Return address of proper part of the buffer */ 839 return ptr->mem_buffer + (start_row - ptr->cur_start_row); 840 } 841 842 843 METHODDEF(JBLOCKARRAY) 844 access_virt_barray (j_common_ptr cinfo, jvirt_barray_ptr ptr, 845 JDIMENSION start_row, JDIMENSION num_rows, 846 boolean writable) 847 /* Access the part of a virtual block array starting at start_row */ 848 /* and extending for num_rows rows. writable is true if */ 849 /* caller intends to modify the accessed area. */ 850 { 851 JDIMENSION end_row = start_row + num_rows; 852 JDIMENSION undef_row; 853 854 /* debugging check */ 855 if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || 856 ptr->mem_buffer == NULL) 857 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 858 859 /* Make the desired part of the virtual array accessible */ 860 if (start_row < ptr->cur_start_row || 861 end_row > ptr->cur_start_row+ptr->rows_in_mem) { 862 if (! ptr->b_s_open) 863 ERREXIT(cinfo, JERR_VIRTUAL_BUG); 864 /* Flush old buffer contents if necessary */ 865 if (ptr->dirty) { 866 do_barray_io(cinfo, ptr, TRUE); 867 ptr->dirty = FALSE; 868 } 869 /* Decide what part of virtual array to access. 870 * Algorithm: if target address > current window, assume forward scan, 871 * load starting at target address. If target address < current window, 872 * assume backward scan, load so that target area is top of window. 873 * Note that when switching from forward write to forward read, will have 874 * start_row = 0, so the limiting case applies and we load from 0 anyway. 875 */ 876 if (start_row > ptr->cur_start_row) { 877 ptr->cur_start_row = start_row; 878 } else { 879 /* use long arithmetic here to avoid overflow & unsigned problems */ 880 long ltemp; 881 882 ltemp = (long) end_row - (long) ptr->rows_in_mem; 883 if (ltemp < 0) 884 ltemp = 0; /* don't fall off front end of file */ 885 ptr->cur_start_row = (JDIMENSION) ltemp; 886 } 887 /* Read in the selected part of the array. 888 * During the initial write pass, we will do no actual read 889 * because the selected part is all undefined. 890 */ 891 do_barray_io(cinfo, ptr, FALSE); 892 } 893 /* Ensure the accessed part of the array is defined; prezero if needed. 894 * To improve locality of access, we only prezero the part of the array 895 * that the caller is about to access, not the entire in-memory array. 896 */ 897 if (ptr->first_undef_row < end_row) { 898 if (ptr->first_undef_row < start_row) { 899 if (writable) /* writer skipped over a section of array */ 900 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 901 undef_row = start_row; /* but reader is allowed to read ahead */ 902 } else { 903 undef_row = ptr->first_undef_row; 904 } 905 if (writable) 906 ptr->first_undef_row = end_row; 907 if (ptr->pre_zero) { 908 size_t bytesperrow = (size_t) ptr->blocksperrow * SIZEOF(JBLOCK); 909 undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */ 910 end_row -= ptr->cur_start_row; 911 while (undef_row < end_row) { 912 jzero_far((void FAR *) ptr->mem_buffer[undef_row], bytesperrow); 913 undef_row++; 914 } 915 } else { 916 if (! writable) /* reader looking at undefined data */ 917 ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); 918 } 919 } 920 /* Flag the buffer dirty if caller will write in it */ 921 if (writable) 922 ptr->dirty = TRUE; 923 /* Return address of proper part of the buffer */ 924 return ptr->mem_buffer + (start_row - ptr->cur_start_row); 925 } 926 927 928 /* 929 * Release all objects belonging to a specified pool. 930 */ 931 932 METHODDEF(void) 933 free_pool (j_common_ptr cinfo, int pool_id) 934 { 935 my_mem_ptr mem = (my_mem_ptr) cinfo->mem; 936 small_pool_ptr shdr_ptr; 937 large_pool_ptr lhdr_ptr; 938 size_t space_freed; 939 940 if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) 941 ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ 942 943 #ifdef MEM_STATS 944 if (cinfo->err->trace_level > 1) 945 print_mem_stats(cinfo, pool_id); /* print pool's memory usage statistics */ 946 #endif 947 948 /* If freeing IMAGE pool, close any virtual arrays first */ 949 if (pool_id == JPOOL_IMAGE) { 950 jvirt_sarray_ptr sptr; 951 jvirt_barray_ptr bptr; 952 953 for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { 954 if (sptr->b_s_open) { /* there may be no backing store */ 955 sptr->b_s_open = FALSE; /* prevent recursive close if error */ 956 (*sptr->b_s_info.close_backing_store) (cinfo, & sptr->b_s_info); 957 } 958 } 959 mem->virt_sarray_list = NULL; 960 for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { 961 if (bptr->b_s_open) { /* there may be no backing store */ 962 bptr->b_s_open = FALSE; /* prevent recursive close if error */ 963 (*bptr->b_s_info.close_backing_store) (cinfo, & bptr->b_s_info); 964 } 965 } 966 mem->virt_barray_list = NULL; 967 } 968 969 /* Release large objects */ 970 lhdr_ptr = mem->large_list[pool_id]; 971 mem->large_list[pool_id] = NULL; 972 973 while (lhdr_ptr != NULL) { 974 large_pool_ptr next_lhdr_ptr = lhdr_ptr->hdr.next; 975 space_freed = lhdr_ptr->hdr.bytes_used + 976 lhdr_ptr->hdr.bytes_left + 977 SIZEOF(large_pool_hdr); 978 jpeg_free_large(cinfo, (void FAR *) lhdr_ptr, space_freed); 979 mem->total_space_allocated -= space_freed; 980 lhdr_ptr = next_lhdr_ptr; 981 } 982 983 /* Release small objects */ 984 shdr_ptr = mem->small_list[pool_id]; 985 mem->small_list[pool_id] = NULL; 986 987 while (shdr_ptr != NULL) { 988 small_pool_ptr next_shdr_ptr = shdr_ptr->hdr.next; 989 space_freed = shdr_ptr->hdr.bytes_used + 990 shdr_ptr->hdr.bytes_left + 991 SIZEOF(small_pool_hdr); 992 jpeg_free_small(cinfo, (void *) shdr_ptr, space_freed); 993 mem->total_space_allocated -= space_freed; 994 shdr_ptr = next_shdr_ptr; 995 } 996 } 997 998 999 /* 1000 * Close up shop entirely. 1001 * Note that this cannot be called unless cinfo->mem is non-NULL. 1002 */ 1003 1004 METHODDEF(void) 1005 self_destruct (j_common_ptr cinfo) 1006 { 1007 int pool; 1008 1009 /* Close all backing store, release all memory. 1010 * Releasing pools in reverse order might help avoid fragmentation 1011 * with some (brain-damaged) malloc libraries. 1012 */ 1013 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { 1014 free_pool(cinfo, pool); 1015 } 1016 1017 /* Release the memory manager control block too. */ 1018 jpeg_free_small(cinfo, (void *) cinfo->mem, SIZEOF(my_memory_mgr)); 1019 cinfo->mem = NULL; /* ensures I will be called only once */ 1020 1021 jpeg_mem_term(cinfo); /* system-dependent cleanup */ 1022 } 1023 1024 1025 /* 1026 * Memory manager initialization. 1027 * When this is called, only the error manager pointer is valid in cinfo! 1028 */ 1029 1030 GLOBAL(void) 1031 jinit_memory_mgr (j_common_ptr cinfo) 1032 { 1033 my_mem_ptr mem; 1034 long max_to_use; 1035 int pool; 1036 size_t test_mac; 1037 1038 cinfo->mem = NULL; /* for safety if init fails */ 1039 1040 /* Check for configuration errors. 1041 * SIZEOF(ALIGN_TYPE) should be a power of 2; otherwise, it probably 1042 * doesn't reflect any real hardware alignment requirement. 1043 * The test is a little tricky: for X>0, X and X-1 have no one-bits 1044 * in common if and only if X is a power of 2, ie has only one one-bit. 1045 * Some compilers may give an "unreachable code" warning here; ignore it. 1046 */ 1047 if ((SIZEOF(ALIGN_TYPE) & (SIZEOF(ALIGN_TYPE)-1)) != 0) 1048 ERREXIT(cinfo, JERR_BAD_ALIGN_TYPE); 1049 /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be 1050 * a multiple of SIZEOF(ALIGN_TYPE). 1051 * Again, an "unreachable code" warning may be ignored here. 1052 * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK. 1053 */ 1054 test_mac = (size_t) MAX_ALLOC_CHUNK; 1055 if ((long) test_mac != MAX_ALLOC_CHUNK || 1056 (MAX_ALLOC_CHUNK % SIZEOF(ALIGN_TYPE)) != 0) 1057 ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK); 1058 1059 max_to_use = jpeg_mem_init(cinfo); /* system-dependent initialization */ 1060 1061 /* Attempt to allocate memory manager's control block */ 1062 mem = (my_mem_ptr) jpeg_get_small(cinfo, SIZEOF(my_memory_mgr)); 1063 1064 if (mem == NULL) { 1065 jpeg_mem_term(cinfo); /* system-dependent cleanup */ 1066 ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 0); 1067 } 1068 1069 /* OK, fill in the method pointers */ 1070 mem->pub.alloc_small = alloc_small; 1071 mem->pub.alloc_large = alloc_large; 1072 mem->pub.alloc_sarray = alloc_sarray; 1073 mem->pub.alloc_barray = alloc_barray; 1074 mem->pub.request_virt_sarray = request_virt_sarray; 1075 mem->pub.request_virt_barray = request_virt_barray; 1076 mem->pub.realize_virt_arrays = realize_virt_arrays; 1077 mem->pub.access_virt_sarray = access_virt_sarray; 1078 mem->pub.access_virt_barray = access_virt_barray; 1079 mem->pub.free_pool = free_pool; 1080 mem->pub.self_destruct = self_destruct; 1081 1082 /* Make MAX_ALLOC_CHUNK accessible to other modules */ 1083 mem->pub.max_alloc_chunk = MAX_ALLOC_CHUNK; 1084 1085 /* Initialize working state */ 1086 mem->pub.max_memory_to_use = max_to_use; 1087 1088 for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { 1089 mem->small_list[pool] = NULL; 1090 mem->large_list[pool] = NULL; 1091 } 1092 mem->virt_sarray_list = NULL; 1093 mem->virt_barray_list = NULL; 1094 1095 mem->total_space_allocated = SIZEOF(my_memory_mgr); 1096 1097 /* Declare ourselves open for business */ 1098 cinfo->mem = & mem->pub; 1099 1100 /* Check for an environment variable JPEGMEM; if found, override the 1101 * default max_memory setting from jpeg_mem_init. Note that the 1102 * surrounding application may again override this value. 1103 * If your system doesn't support getenv(), define NO_GETENV to disable 1104 * this feature. 1105 */ 1106 #ifndef NO_GETENV 1107 { char * memenv; 1108 1109 if ((memenv = getenv("JPEGMEM")) != NULL) { 1110 char ch = 'x'; 1111 1112 if (sscanf(memenv, "%ld%c", &max_to_use, &ch) > 0) { 1113 if (ch == 'm' || ch == 'M') 1114 max_to_use *= 1000L; 1115 mem->pub.max_memory_to_use = max_to_use * 1000L; 1116 } 1117 } 1118 } 1119 #endif 1120 1121 } 1122 1123 #endif //_FX_JPEG_TURBO_ 1124
