diff options
Diffstat (limited to 'src/libjpeg/jmemmgr.c')
| -rw-r--r-- | src/libjpeg/jmemmgr.c | 1118 |
1 files changed, 1118 insertions, 0 deletions
diff --git a/src/libjpeg/jmemmgr.c b/src/libjpeg/jmemmgr.c new file mode 100644 index 0000000..d801b32 --- /dev/null +++ b/src/libjpeg/jmemmgr.c @@ -0,0 +1,1118 @@ +/* + * jmemmgr.c + * + * Copyright (C) 1991-1997, Thomas G. Lane. + * This file is part of the Independent JPEG Group's software. + * For conditions of distribution and use, see the accompanying README file. + * + * This file contains the JPEG system-independent memory management + * routines. This code is usable across a wide variety of machines; most + * of the system dependencies have been isolated in a separate file. + * The major functions provided here are: + * * pool-based allocation and freeing of memory; + * * policy decisions about how to divide available memory among the + * virtual arrays; + * * control logic for swapping virtual arrays between main memory and + * backing storage. + * The separate system-dependent file provides the actual backing-storage + * access code, and it contains the policy decision about how much total + * main memory to use. + * This file is system-dependent in the sense that some of its functions + * are unnecessary in some systems. For example, if there is enough virtual + * memory so that backing storage will never be used, much of the virtual + * array control logic could be removed. (Of course, if you have that much + * memory then you shouldn't care about a little bit of unused code...) + */ + +#define JPEG_INTERNALS +#define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */ +#include "jinclude.h" +#include "jpeglib.h" +#include "jmemsys.h" /* import the system-dependent declarations */ + +#ifndef NO_GETENV +#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */ +extern char * getenv JPP((const char * name)); +#endif +#endif + + +/* + * Some important notes: + * The allocation routines provided here must never return NULL. + * They should exit to error_exit if unsuccessful. + * + * It's not a good idea to try to merge the sarray and barray routines, + * even though they are textually almost the same, because samples are + * usually stored as bytes while coefficients are shorts or ints. Thus, + * in machines where byte pointers have a different representation from + * word pointers, the resulting machine code could not be the same. + */ + + +/* + * Many machines require storage alignment: longs must start on 4-byte + * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc() + * always returns pointers that are multiples of the worst-case alignment + * requirement, and we had better do so too. + * There isn't any really portable way to determine the worst-case alignment + * requirement. This module assumes that the alignment requirement is + * multiples of sizeof(ALIGN_TYPE). + * By default, we define ALIGN_TYPE as double. This is necessary on some + * workstations (where doubles really do need 8-byte alignment) and will work + * fine on nearly everything. If your machine has lesser alignment needs, + * you can save a few bytes by making ALIGN_TYPE smaller. + * The only place I know of where this will NOT work is certain Macintosh + * 680x0 compilers that define double as a 10-byte IEEE extended float. + * Doing 10-byte alignment is counterproductive because longwords won't be + * aligned well. Put "#define ALIGN_TYPE long" in jconfig.h if you have + * such a compiler. + */ + +#ifndef ALIGN_TYPE /* so can override from jconfig.h */ +#define ALIGN_TYPE double +#endif + + +/* + * We allocate objects from "pools", where each pool is gotten with a single + * request to jpeg_get_small() or jpeg_get_large(). There is no per-object + * overhead within a pool, except for alignment padding. Each pool has a + * header with a link to the next pool of the same class. + * Small and large pool headers are identical except that the latter's + * link pointer must be FAR on 80x86 machines. + * Notice that the "real" header fields are union'ed with a dummy ALIGN_TYPE + * field. This forces the compiler to make SIZEOF(small_pool_hdr) a multiple + * of the alignment requirement of ALIGN_TYPE. + */ + +typedef union small_pool_struct * small_pool_ptr; + +typedef union small_pool_struct { + struct { + small_pool_ptr next; /* next in list of pools */ + size_t bytes_used; /* how many bytes already used within pool */ + size_t bytes_left; /* bytes still available in this pool */ + } hdr; + ALIGN_TYPE dummy; /* included in union to ensure alignment */ +} small_pool_hdr; + +typedef union large_pool_struct FAR * large_pool_ptr; + +typedef union large_pool_struct { + struct { + large_pool_ptr next; /* next in list of pools */ + size_t bytes_used; /* how many bytes already used within pool */ + size_t bytes_left; /* bytes still available in this pool */ + } hdr; + ALIGN_TYPE dummy; /* included in union to ensure alignment */ +} large_pool_hdr; + + +/* + * Here is the full definition of a memory manager object. + */ + +typedef struct { + struct jpeg_memory_mgr pub; /* public fields */ + + /* Each pool identifier (lifetime class) names a linked list of pools. */ + small_pool_ptr small_list[JPOOL_NUMPOOLS]; + large_pool_ptr large_list[JPOOL_NUMPOOLS]; + + /* Since we only have one lifetime class of virtual arrays, only one + * linked list is necessary (for each datatype). Note that the virtual + * array control blocks being linked together are actually stored somewhere + * in the small-pool list. + */ + jvirt_sarray_ptr virt_sarray_list; + jvirt_barray_ptr virt_barray_list; + + /* This counts total space obtained from jpeg_get_small/large */ + long total_space_allocated; + + /* alloc_sarray and alloc_barray set this value for use by virtual + * array routines. + */ + JDIMENSION last_rowsperchunk; /* from most recent alloc_sarray/barray */ +} my_memory_mgr; + +typedef my_memory_mgr * my_mem_ptr; + + +/* + * The control blocks for virtual arrays. + * Note that these blocks are allocated in the "small" pool area. + * System-dependent info for the associated backing store (if any) is hidden + * inside the backing_store_info struct. + */ + +struct jvirt_sarray_control { + JSAMPARRAY mem_buffer; /* => the in-memory buffer */ + JDIMENSION rows_in_array; /* total virtual array height */ + JDIMENSION samplesperrow; /* width of array (and of memory buffer) */ + JDIMENSION maxaccess; /* max rows accessed by access_virt_sarray */ + JDIMENSION rows_in_mem; /* height of memory buffer */ + JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */ + JDIMENSION cur_start_row; /* first logical row # in the buffer */ + JDIMENSION first_undef_row; /* row # of first uninitialized row */ + boolean pre_zero; /* pre-zero mode requested? */ + boolean dirty; /* do current buffer contents need written? */ + boolean b_s_open; /* is backing-store data valid? */ + jvirt_sarray_ptr next; /* link to next virtual sarray control block */ + backing_store_info b_s_info; /* System-dependent control info */ +}; + +struct jvirt_barray_control { + JBLOCKARRAY mem_buffer; /* => the in-memory buffer */ + JDIMENSION rows_in_array; /* total virtual array height */ + JDIMENSION blocksperrow; /* width of array (and of memory buffer) */ + JDIMENSION maxaccess; /* max rows accessed by access_virt_barray */ + JDIMENSION rows_in_mem; /* height of memory buffer */ + JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */ + JDIMENSION cur_start_row; /* first logical row # in the buffer */ + JDIMENSION first_undef_row; /* row # of first uninitialized row */ + boolean pre_zero; /* pre-zero mode requested? */ + boolean dirty; /* do current buffer contents need written? */ + boolean b_s_open; /* is backing-store data valid? */ + jvirt_barray_ptr next; /* link to next virtual barray control block */ + backing_store_info b_s_info; /* System-dependent control info */ +}; + + +#ifdef MEM_STATS /* optional extra stuff for statistics */ + +LOCAL(void) +print_mem_stats (j_common_ptr cinfo, int pool_id) +{ + my_mem_ptr mem = (my_mem_ptr) cinfo->mem; + small_pool_ptr shdr_ptr; + large_pool_ptr lhdr_ptr; + + /* Since this is only a debugging stub, we can cheat a little by using + * fprintf directly rather than going through the trace message code. + * This is helpful because message parm array can't handle longs. + */ + fprintf(stderr, "Freeing pool %d, total space = %ld\n", + pool_id, mem->total_space_allocated); + + for (lhdr_ptr = mem->large_list[pool_id]; lhdr_ptr != NULL; + lhdr_ptr = lhdr_ptr->hdr.next) { + fprintf(stderr, " Large chunk used %ld\n", + (long) lhdr_ptr->hdr.bytes_used); + } + + for (shdr_ptr = mem->small_list[pool_id]; shdr_ptr != NULL; + shdr_ptr = shdr_ptr->hdr.next) { + fprintf(stderr, " Small chunk used %ld free %ld\n", + (long) shdr_ptr->hdr.bytes_used, + (long) shdr_ptr->hdr.bytes_left); + } +} + +#endif /* MEM_STATS */ + + +LOCAL(void) +out_of_memory (j_common_ptr cinfo, int which) +/* Report an out-of-memory error and stop execution */ +/* If we compiled MEM_STATS support, report alloc requests before dying */ +{ +#ifdef MEM_STATS + cinfo->err->trace_level = 2; /* force self_destruct to report stats */ +#endif + ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, which); +} + + +/* + * Allocation of "small" objects. + * + * For these, we use pooled storage. When a new pool must be created, + * we try to get enough space for the current request plus a "slop" factor, + * where the slop will be the amount of leftover space in the new pool. + * The speed vs. space tradeoff is largely determined by the slop values. + * A different slop value is provided for each pool class (lifetime), + * and we also distinguish the first pool of a class from later ones. + * NOTE: the values given work fairly well on both 16- and 32-bit-int + * machines, but may be too small if longs are 64 bits or more. + */ + +static const size_t first_pool_slop[JPOOL_NUMPOOLS] = +{ + 1600, /* first PERMANENT pool */ + 16000 /* first IMAGE pool */ +}; + +static const size_t extra_pool_slop[JPOOL_NUMPOOLS] = +{ + 0, /* additional PERMANENT pools */ + 5000 /* additional IMAGE pools */ +}; + +#define MIN_SLOP 50 /* greater than 0 to avoid futile looping */ + + +METHODDEF(void *) +alloc_small (j_common_ptr cinfo, int pool_id, size_t sizeofobject) +/* Allocate a "small" object */ +{ + my_mem_ptr mem = (my_mem_ptr) cinfo->mem; + small_pool_ptr hdr_ptr, prev_hdr_ptr; + char * data_ptr; + size_t odd_bytes, min_request, slop; + + /* Check for unsatisfiable request (do now to ensure no overflow below) */ + if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(small_pool_hdr))) + out_of_memory(cinfo, 1); /* request exceeds malloc's ability */ + + /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */ + odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE); + if (odd_bytes > 0) + sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes; + + /* See if space is available in any existing pool */ + if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) + ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ + prev_hdr_ptr = NULL; + hdr_ptr = mem->small_list[pool_id]; + while (hdr_ptr != NULL) { + if (hdr_ptr->hdr.bytes_left >= sizeofobject) + break; /* found pool with enough space */ + prev_hdr_ptr = hdr_ptr; + hdr_ptr = hdr_ptr->hdr.next; + } + + /* Time to make a new pool? */ + if (hdr_ptr == NULL) { + /* min_request is what we need now, slop is what will be leftover */ + min_request = sizeofobject + SIZEOF(small_pool_hdr); + if (prev_hdr_ptr == NULL) /* first pool in class? */ + slop = first_pool_slop[pool_id]; + else + slop = extra_pool_slop[pool_id]; + /* Don't ask for more than MAX_ALLOC_CHUNK */ + if (slop > (size_t) (MAX_ALLOC_CHUNK-min_request)) + slop = (size_t) (MAX_ALLOC_CHUNK-min_request); + /* Try to get space, if fail reduce slop and try again */ + for (;;) { + hdr_ptr = (small_pool_ptr) jpeg_get_small(cinfo, min_request + slop); + if (hdr_ptr != NULL) + break; + slop /= 2; + if (slop < MIN_SLOP) /* give up when it gets real small */ + out_of_memory(cinfo, 2); /* jpeg_get_small failed */ + } + mem->total_space_allocated += min_request + slop; + /* Success, initialize the new pool header and add to end of list */ + hdr_ptr->hdr.next = NULL; + hdr_ptr->hdr.bytes_used = 0; + hdr_ptr->hdr.bytes_left = sizeofobject + slop; + if (prev_hdr_ptr == NULL) /* first pool in class? */ + mem->small_list[pool_id] = hdr_ptr; + else + prev_hdr_ptr->hdr.next = hdr_ptr; + } + + /* OK, allocate the object from the current pool */ + data_ptr = (char *) (hdr_ptr + 1); /* point to first data byte in pool */ + data_ptr += hdr_ptr->hdr.bytes_used; /* point to place for object */ + hdr_ptr->hdr.bytes_used += sizeofobject; + hdr_ptr->hdr.bytes_left -= sizeofobject; + + return (void *) data_ptr; +} + + +/* + * Allocation of "large" objects. + * + * The external semantics of these are the same as "small" objects, + * except that FAR pointers are used on 80x86. However the pool + * management heuristics are quite different. We assume that each + * request is large enough that it may as well be passed directly to + * jpeg_get_large; the pool management just links everything together + * so that we can free it all on demand. + * Note: the major use of "large" objects is in JSAMPARRAY and JBLOCKARRAY + * structures. The routines that create these structures (see below) + * deliberately bunch rows together to ensure a large request size. + */ + +METHODDEF(void FAR *) +alloc_large (j_common_ptr cinfo, int pool_id, size_t sizeofobject) +/* Allocate a "large" object */ +{ + my_mem_ptr mem = (my_mem_ptr) cinfo->mem; + large_pool_ptr hdr_ptr; + size_t odd_bytes; + + /* Check for unsatisfiable request (do now to ensure no overflow below) */ + if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr))) + out_of_memory(cinfo, 3); /* request exceeds malloc's ability */ + + /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */ + odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE); + if (odd_bytes > 0) + sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes; + + /* Always make a new pool */ + if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) + ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ + + hdr_ptr = (large_pool_ptr) jpeg_get_large(cinfo, sizeofobject + + SIZEOF(large_pool_hdr)); + if (hdr_ptr == NULL) + out_of_memory(cinfo, 4); /* jpeg_get_large failed */ + mem->total_space_allocated += sizeofobject + SIZEOF(large_pool_hdr); + + /* Success, initialize the new pool header and add to list */ + hdr_ptr->hdr.next = mem->large_list[pool_id]; + /* We maintain space counts in each pool header for statistical purposes, + * even though they are not needed for allocation. + */ + hdr_ptr->hdr.bytes_used = sizeofobject; + hdr_ptr->hdr.bytes_left = 0; + mem->large_list[pool_id] = hdr_ptr; + + return (void FAR *) (hdr_ptr + 1); /* point to first data byte in pool */ +} + + +/* + * Creation of 2-D sample arrays. + * The pointers are in near heap, the samples themselves in FAR heap. + * + * To minimize allocation overhead and to allow I/O of large contiguous + * blocks, we allocate the sample rows in groups of as many rows as possible + * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request. + * NB: the virtual array control routines, later in this file, know about + * this chunking of rows. The rowsperchunk value is left in the mem manager + * object so that it can be saved away if this sarray is the workspace for + * a virtual array. + */ + +METHODDEF(JSAMPARRAY) +alloc_sarray (j_common_ptr cinfo, int pool_id, + JDIMENSION samplesperrow, JDIMENSION numrows) +/* Allocate a 2-D sample array */ +{ + my_mem_ptr mem = (my_mem_ptr) cinfo->mem; + JSAMPARRAY result; + JSAMPROW workspace; + JDIMENSION rowsperchunk, currow, i; + long ltemp; + + /* Calculate max # of rows allowed in one allocation chunk */ + ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) / + ((long) samplesperrow * SIZEOF(JSAMPLE)); + if (ltemp <= 0) + ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); + if (ltemp < (long) numrows) + rowsperchunk = (JDIMENSION) ltemp; + else + rowsperchunk = numrows; + mem->last_rowsperchunk = rowsperchunk; + + /* Get space for row pointers (small object) */ + result = (JSAMPARRAY) alloc_small(cinfo, pool_id, + (size_t) (numrows * SIZEOF(JSAMPROW))); + + /* Get the rows themselves (large objects) */ + currow = 0; + while (currow < numrows) { + rowsperchunk = MIN(rowsperchunk, numrows - currow); + workspace = (JSAMPROW) alloc_large(cinfo, pool_id, + (size_t) ((size_t) rowsperchunk * (size_t) samplesperrow + * SIZEOF(JSAMPLE))); + for (i = rowsperchunk; i > 0; i--) { + result[currow++] = workspace; + workspace += samplesperrow; + } + } + + return result; +} + + +/* + * Creation of 2-D coefficient-block arrays. + * This is essentially the same as the code for sample arrays, above. + */ + +METHODDEF(JBLOCKARRAY) +alloc_barray (j_common_ptr cinfo, int pool_id, + JDIMENSION blocksperrow, JDIMENSION numrows) +/* Allocate a 2-D coefficient-block array */ +{ + my_mem_ptr mem = (my_mem_ptr) cinfo->mem; + JBLOCKARRAY result; + JBLOCKROW workspace; + JDIMENSION rowsperchunk, currow, i; + long ltemp; + + /* Calculate max # of rows allowed in one allocation chunk */ + ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) / + ((long) blocksperrow * SIZEOF(JBLOCK)); + if (ltemp <= 0) + ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); + if (ltemp < (long) numrows) + rowsperchunk = (JDIMENSION) ltemp; + else + rowsperchunk = numrows; + mem->last_rowsperchunk = rowsperchunk; + + /* Get space for row pointers (small object) */ + result = (JBLOCKARRAY) alloc_small(cinfo, pool_id, + (size_t) (numrows * SIZEOF(JBLOCKROW))); + + /* Get the rows themselves (large objects) */ + currow = 0; + while (currow < numrows) { + rowsperchunk = MIN(rowsperchunk, numrows - currow); + workspace = (JBLOCKROW) alloc_large(cinfo, pool_id, + (size_t) ((size_t) rowsperchunk * (size_t) blocksperrow + * SIZEOF(JBLOCK))); + for (i = rowsperchunk; i > 0; i--) { + result[currow++] = workspace; + workspace += blocksperrow; + } + } + + return result; +} + + +/* + * About virtual array management: + * + * The above "normal" array routines are only used to allocate strip buffers + * (as wide as the image, but just a few rows high). Full-image-sized buffers + * are handled as "virtual" arrays. The array is still accessed a strip at a + * time, but the memory manager must save the whole array for repeated + * accesses. The intended implementation is that there is a strip buffer in + * memory (as high as is possible given the desired memory limit), plus a + * backing file that holds the rest of the array. + * + * The request_virt_array routines are told the total size of the image and + * the maximum number of rows that will be accessed at once. The in-memory + * buffer must be at least as large as the maxaccess value. + * + * The request routines create control blocks but not the in-memory buffers. + * That is postponed until realize_virt_arrays is called. At that time the + * total amount of space needed is known (approximately, anyway), so free + * memory can be divided up fairly. + * + * The access_virt_array routines are responsible for making a specific strip + * area accessible (after reading or writing the backing file, if necessary). + * Note that the access routines are told whether the caller intends to modify + * the accessed strip; during a read-only pass this saves having to rewrite + * data to disk. The access routines are also responsible for pre-zeroing + * any newly accessed rows, if pre-zeroing was requested. + * + * In current usage, the access requests are usually for nonoverlapping + * strips; that is, successive access start_row numbers differ by exactly + * num_rows = maxaccess. This means we can get good performance with simple + * buffer dump/reload logic, by making the in-memory buffer be a multiple + * of the access height; then there will never be accesses across bufferload + * boundaries. The code will still work with overlapping access requests, + * but it doesn't handle bufferload overlaps very efficiently. + */ + + +METHODDEF(jvirt_sarray_ptr) +request_virt_sarray (j_common_ptr cinfo, int pool_id, boolean pre_zero, + JDIMENSION samplesperrow, JDIMENSION numrows, + JDIMENSION maxaccess) +/* Request a virtual 2-D sample array */ +{ + my_mem_ptr mem = (my_mem_ptr) cinfo->mem; + jvirt_sarray_ptr result; + + /* Only IMAGE-lifetime virtual arrays are currently supported */ + if (pool_id != JPOOL_IMAGE) + ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ + + /* get control block */ + result = (jvirt_sarray_ptr) alloc_small(cinfo, pool_id, + SIZEOF(struct jvirt_sarray_control)); + + result->mem_buffer = NULL; /* marks array not yet realized */ + result->rows_in_array = numrows; + result->samplesperrow = samplesperrow; + result->maxaccess = maxaccess; + result->pre_zero = pre_zero; + result->b_s_open = FALSE; /* no associated backing-store object */ + result->next = mem->virt_sarray_list; /* add to list of virtual arrays */ + mem->virt_sarray_list = result; + + return result; +} + + +METHODDEF(jvirt_barray_ptr) +request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero, + JDIMENSION blocksperrow, JDIMENSION numrows, + JDIMENSION maxaccess) +/* Request a virtual 2-D coefficient-block array */ +{ + my_mem_ptr mem = (my_mem_ptr) cinfo->mem; + jvirt_barray_ptr result; + + /* Only IMAGE-lifetime virtual arrays are currently supported */ + if (pool_id != JPOOL_IMAGE) + ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ + + /* get control block */ + result = (jvirt_barray_ptr) alloc_small(cinfo, pool_id, + SIZEOF(struct jvirt_barray_control)); + + result->mem_buffer = NULL; /* marks array not yet realized */ + result->rows_in_array = numrows; + result->blocksperrow = blocksperrow; + result->maxaccess = maxaccess; + result->pre_zero = pre_zero; + result->b_s_open = FALSE; /* no associated backing-store object */ + result->next = mem->virt_barray_list; /* add to list of virtual arrays */ + mem->virt_barray_list = result; + + return result; +} + + +METHODDEF(void) +realize_virt_arrays (j_common_ptr cinfo) +/* Allocate the in-memory buffers for any unrealized virtual arrays */ +{ + my_mem_ptr mem = (my_mem_ptr) cinfo->mem; + long space_per_minheight, maximum_space, avail_mem; + long minheights, max_minheights; + jvirt_sarray_ptr sptr; + jvirt_barray_ptr bptr; + + /* Compute the minimum space needed (maxaccess rows in each buffer) + * and the maximum space needed (full image height in each buffer). + * These may be of use to the system-dependent jpeg_mem_available routine. + */ + space_per_minheight = 0; + maximum_space = 0; + for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { + if (sptr->mem_buffer == NULL) { /* if not realized yet */ + space_per_minheight += (long) sptr->maxaccess * + (long) sptr->samplesperrow * SIZEOF(JSAMPLE); + maximum_space += (long) sptr->rows_in_array * + (long) sptr->samplesperrow * SIZEOF(JSAMPLE); + } + } + for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { + if (bptr->mem_buffer == NULL) { /* if not realized yet */ + space_per_minheight += (long) bptr->maxaccess * + (long) bptr->blocksperrow * SIZEOF(JBLOCK); + maximum_space += (long) bptr->rows_in_array * + (long) bptr->blocksperrow * SIZEOF(JBLOCK); + } + } + + if (space_per_minheight <= 0) + return; /* no unrealized arrays, no work */ + + /* Determine amount of memory to actually use; this is system-dependent. */ + avail_mem = jpeg_mem_available(cinfo, space_per_minheight, maximum_space, + mem->total_space_allocated); + + /* If the maximum space needed is available, make all the buffers full + * height; otherwise parcel it out with the same number of minheights + * in each buffer. + */ + if (avail_mem >= maximum_space) + max_minheights = 1000000000L; + else { + max_minheights = avail_mem / space_per_minheight; + /* If there doesn't seem to be enough space, try to get the minimum + * anyway. This allows a "stub" implementation of jpeg_mem_available(). + */ + if (max_minheights <= 0) + max_minheights = 1; + } + + /* Allocate the in-memory buffers and initialize backing store as needed. */ + + for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { + if (sptr->mem_buffer == NULL) { /* if not realized yet */ + minheights = ((long) sptr->rows_in_array - 1L) / sptr->maxaccess + 1L; + if (minheights <= max_minheights) { + /* This buffer fits in memory */ + sptr->rows_in_mem = sptr->rows_in_array; + } else { + /* It doesn't fit in memory, create backing store. */ + sptr->rows_in_mem = (JDIMENSION) (max_minheights * sptr->maxaccess); + jpeg_open_backing_store(cinfo, & sptr->b_s_info, + (long) sptr->rows_in_array * + (long) sptr->samplesperrow * + (long) SIZEOF(JSAMPLE)); + sptr->b_s_open = TRUE; + } + sptr->mem_buffer = alloc_sarray(cinfo, JPOOL_IMAGE, + sptr->samplesperrow, sptr->rows_in_mem); + sptr->rowsperchunk = mem->last_rowsperchunk; + sptr->cur_start_row = 0; + sptr->first_undef_row = 0; + sptr->dirty = FALSE; + } + } + + for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { + if (bptr->mem_buffer == NULL) { /* if not realized yet */ + minheights = ((long) bptr->rows_in_array - 1L) / bptr->maxaccess + 1L; + if (minheights <= max_minheights) { + /* This buffer fits in memory */ + bptr->rows_in_mem = bptr->rows_in_array; + } else { + /* It doesn't fit in memory, create backing store. */ + bptr->rows_in_mem = (JDIMENSION) (max_minheights * bptr->maxaccess); + jpeg_open_backing_store(cinfo, & bptr->b_s_info, + (long) bptr->rows_in_array * + (long) bptr->blocksperrow * + (long) SIZEOF(JBLOCK)); + bptr->b_s_open = TRUE; + } + bptr->mem_buffer = alloc_barray(cinfo, JPOOL_IMAGE, + bptr->blocksperrow, bptr->rows_in_mem); + bptr->rowsperchunk = mem->last_rowsperchunk; + bptr->cur_start_row = 0; + bptr->first_undef_row = 0; + bptr->dirty = FALSE; + } + } +} + + +LOCAL(void) +do_sarray_io (j_common_ptr cinfo, jvirt_sarray_ptr ptr, boolean writing) +/* Do backing store read or write of a virtual sample array */ +{ + long bytesperrow, file_offset, byte_count, rows, thisrow, i; + + bytesperrow = (long) ptr->samplesperrow * SIZEOF(JSAMPLE); + file_offset = ptr->cur_start_row * bytesperrow; + /* Loop to read or write each allocation chunk in mem_buffer */ + for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) { + /* One chunk, but check for short chunk at end of buffer */ + rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i); + /* Transfer no more than is currently defined */ + thisrow = (long) ptr->cur_start_row + i; + rows = MIN(rows, (long) ptr->first_undef_row - thisrow); + /* Transfer no more than fits in file */ + rows = MIN(rows, (long) ptr->rows_in_array - thisrow); + if (rows <= 0) /* this chunk might be past end of file! */ + break; + byte_count = rows * bytesperrow; + if (writing) + (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, + (void FAR *) ptr->mem_buffer[i], + file_offset, byte_count); + else + (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, + (void FAR *) ptr->mem_buffer[i], + file_offset, byte_count); + file_offset += byte_count; + } +} + + +LOCAL(void) +do_barray_io (j_common_ptr cinfo, jvirt_barray_ptr ptr, boolean writing) +/* Do backing store read or write of a virtual coefficient-block array */ +{ + long bytesperrow, file_offset, byte_count, rows, thisrow, i; + + bytesperrow = (long) ptr->blocksperrow * SIZEOF(JBLOCK); + file_offset = ptr->cur_start_row * bytesperrow; + /* Loop to read or write each allocation chunk in mem_buffer */ + for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) { + /* One chunk, but check for short chunk at end of buffer */ + rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i); + /* Transfer no more than is currently defined */ + thisrow = (long) ptr->cur_start_row + i; + rows = MIN(rows, (long) ptr->first_undef_row - thisrow); + /* Transfer no more than fits in file */ + rows = MIN(rows, (long) ptr->rows_in_array - thisrow); + if (rows <= 0) /* this chunk might be past end of file! */ + break; + byte_count = rows * bytesperrow; + if (writing) + (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info, + (void FAR *) ptr->mem_buffer[i], + file_offset, byte_count); + else + (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info, + (void FAR *) ptr->mem_buffer[i], + file_offset, byte_count); + file_offset += byte_count; + } +} + + +METHODDEF(JSAMPARRAY) +access_virt_sarray (j_common_ptr cinfo, jvirt_sarray_ptr ptr, + JDIMENSION start_row, JDIMENSION num_rows, + boolean writable) +/* Access the part of a virtual sample array starting at start_row */ +/* and extending for num_rows rows. writable is true if */ +/* caller intends to modify the accessed area. */ +{ + JDIMENSION end_row = start_row + num_rows; + JDIMENSION undef_row; + + /* debugging check */ + if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || + ptr->mem_buffer == NULL) + ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); + + /* Make the desired part of the virtual array accessible */ + if (start_row < ptr->cur_start_row || + end_row > ptr->cur_start_row+ptr->rows_in_mem) { + if (! ptr->b_s_open) + ERREXIT(cinfo, JERR_VIRTUAL_BUG); + /* Flush old buffer contents if necessary */ + if (ptr->dirty) { + do_sarray_io(cinfo, ptr, TRUE); + ptr->dirty = FALSE; + } + /* Decide what part of virtual array to access. + * Algorithm: if target address > current window, assume forward scan, + * load starting at target address. If target address < current window, + * assume backward scan, load so that target area is top of window. + * Note that when switching from forward write to forward read, will have + * start_row = 0, so the limiting case applies and we load from 0 anyway. + */ + if (start_row > ptr->cur_start_row) { + ptr->cur_start_row = start_row; + } else { + /* use long arithmetic here to avoid overflow & unsigned problems */ + long ltemp; + + ltemp = (long) end_row - (long) ptr->rows_in_mem; + if (ltemp < 0) + ltemp = 0; /* don't fall off front end of file */ + ptr->cur_start_row = (JDIMENSION) ltemp; + } + /* Read in the selected part of the array. + * During the initial write pass, we will do no actual read + * because the selected part is all undefined. + */ + do_sarray_io(cinfo, ptr, FALSE); + } + /* Ensure the accessed part of the array is defined; prezero if needed. + * To improve locality of access, we only prezero the part of the array + * that the caller is about to access, not the entire in-memory array. + */ + if (ptr->first_undef_row < end_row) { + if (ptr->first_undef_row < start_row) { + if (writable) /* writer skipped over a section of array */ + ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); + undef_row = start_row; /* but reader is allowed to read ahead */ + } else { + undef_row = ptr->first_undef_row; + } + if (writable) + ptr->first_undef_row = end_row; + if (ptr->pre_zero) { + size_t bytesperrow = (size_t) ptr->samplesperrow * SIZEOF(JSAMPLE); + undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */ + end_row -= ptr->cur_start_row; + while (undef_row < end_row) { + jzero_far((void FAR *) ptr->mem_buffer[undef_row], bytesperrow); + undef_row++; + } + } else { + if (! writable) /* reader looking at undefined data */ + ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); + } + } + /* Flag the buffer dirty if caller will write in it */ + if (writable) + ptr->dirty = TRUE; + /* Return address of proper part of the buffer */ + return ptr->mem_buffer + (start_row - ptr->cur_start_row); +} + + +METHODDEF(JBLOCKARRAY) +access_virt_barray (j_common_ptr cinfo, jvirt_barray_ptr ptr, + JDIMENSION start_row, JDIMENSION num_rows, + boolean writable) +/* Access the part of a virtual block array starting at start_row */ +/* and extending for num_rows rows. writable is true if */ +/* caller intends to modify the accessed area. */ +{ + JDIMENSION end_row = start_row + num_rows; + JDIMENSION undef_row; + + /* debugging check */ + if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess || + ptr->mem_buffer == NULL) + ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); + + /* Make the desired part of the virtual array accessible */ + if (start_row < ptr->cur_start_row || + end_row > ptr->cur_start_row+ptr->rows_in_mem) { + if (! ptr->b_s_open) + ERREXIT(cinfo, JERR_VIRTUAL_BUG); + /* Flush old buffer contents if necessary */ + if (ptr->dirty) { + do_barray_io(cinfo, ptr, TRUE); + ptr->dirty = FALSE; + } + /* Decide what part of virtual array to access. + * Algorithm: if target address > current window, assume forward scan, + * load starting at target address. If target address < current window, + * assume backward scan, load so that target area is top of window. + * Note that when switching from forward write to forward read, will have + * start_row = 0, so the limiting case applies and we load from 0 anyway. + */ + if (start_row > ptr->cur_start_row) { + ptr->cur_start_row = start_row; + } else { + /* use long arithmetic here to avoid overflow & unsigned problems */ + long ltemp; + + ltemp = (long) end_row - (long) ptr->rows_in_mem; + if (ltemp < 0) + ltemp = 0; /* don't fall off front end of file */ + ptr->cur_start_row = (JDIMENSION) ltemp; + } + /* Read in the selected part of the array. + * During the initial write pass, we will do no actual read + * because the selected part is all undefined. + */ + do_barray_io(cinfo, ptr, FALSE); + } + /* Ensure the accessed part of the array is defined; prezero if needed. + * To improve locality of access, we only prezero the part of the array + * that the caller is about to access, not the entire in-memory array. + */ + if (ptr->first_undef_row < end_row) { + if (ptr->first_undef_row < start_row) { + if (writable) /* writer skipped over a section of array */ + ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); + undef_row = start_row; /* but reader is allowed to read ahead */ + } else { + undef_row = ptr->first_undef_row; + } + if (writable) + ptr->first_undef_row = end_row; + if (ptr->pre_zero) { + size_t bytesperrow = (size_t) ptr->blocksperrow * SIZEOF(JBLOCK); + undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */ + end_row -= ptr->cur_start_row; + while (undef_row < end_row) { + jzero_far((void FAR *) ptr->mem_buffer[undef_row], bytesperrow); + undef_row++; + } + } else { + if (! writable) /* reader looking at undefined data */ + ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS); + } + } + /* Flag the buffer dirty if caller will write in it */ + if (writable) + ptr->dirty = TRUE; + /* Return address of proper part of the buffer */ + return ptr->mem_buffer + (start_row - ptr->cur_start_row); +} + + +/* + * Release all objects belonging to a specified pool. + */ + +METHODDEF(void) +free_pool (j_common_ptr cinfo, int pool_id) +{ + my_mem_ptr mem = (my_mem_ptr) cinfo->mem; + small_pool_ptr shdr_ptr; + large_pool_ptr lhdr_ptr; + size_t space_freed; + + if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS) + ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */ + +#ifdef MEM_STATS + if (cinfo->err->trace_level > 1) + print_mem_stats(cinfo, pool_id); /* print pool's memory usage statistics */ +#endif + + /* If freeing IMAGE pool, close any virtual arrays first */ + if (pool_id == JPOOL_IMAGE) { + jvirt_sarray_ptr sptr; + jvirt_barray_ptr bptr; + + for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) { + if (sptr->b_s_open) { /* there may be no backing store */ + sptr->b_s_open = FALSE; /* prevent recursive close if error */ + (*sptr->b_s_info.close_backing_store) (cinfo, & sptr->b_s_info); + } + } + mem->virt_sarray_list = NULL; + for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) { + if (bptr->b_s_open) { /* there may be no backing store */ + bptr->b_s_open = FALSE; /* prevent recursive close if error */ + (*bptr->b_s_info.close_backing_store) (cinfo, & bptr->b_s_info); + } + } + mem->virt_barray_list = NULL; + } + + /* Release large objects */ + lhdr_ptr = mem->large_list[pool_id]; + mem->large_list[pool_id] = NULL; + + while (lhdr_ptr != NULL) { + large_pool_ptr next_lhdr_ptr = lhdr_ptr->hdr.next; + space_freed = lhdr_ptr->hdr.bytes_used + + lhdr_ptr->hdr.bytes_left + + SIZEOF(large_pool_hdr); + jpeg_free_large(cinfo, (void FAR *) lhdr_ptr, space_freed); + mem->total_space_allocated -= space_freed; + lhdr_ptr = next_lhdr_ptr; + } + + /* Release small objects */ + shdr_ptr = mem->small_list[pool_id]; + mem->small_list[pool_id] = NULL; + + while (shdr_ptr != NULL) { + small_pool_ptr next_shdr_ptr = shdr_ptr->hdr.next; + space_freed = shdr_ptr->hdr.bytes_used + + shdr_ptr->hdr.bytes_left + + SIZEOF(small_pool_hdr); + jpeg_free_small(cinfo, (void *) shdr_ptr, space_freed); + mem->total_space_allocated -= space_freed; + shdr_ptr = next_shdr_ptr; + } +} + + +/* + * Close up shop entirely. + * Note that this cannot be called unless cinfo->mem is non-NULL. + */ + +METHODDEF(void) +self_destruct (j_common_ptr cinfo) +{ + int pool; + + /* Close all backing store, release all memory. + * Releasing pools in reverse order might help avoid fragmentation + * with some (brain-damaged) malloc libraries. + */ + for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { + free_pool(cinfo, pool); + } + + /* Release the memory manager control block too. */ + jpeg_free_small(cinfo, (void *) cinfo->mem, SIZEOF(my_memory_mgr)); + cinfo->mem = NULL; /* ensures I will be called only once */ + + jpeg_mem_term(cinfo); /* system-dependent cleanup */ +} + + +/* + * Memory manager initialization. + * When this is called, only the error manager pointer is valid in cinfo! + */ + +GLOBAL(void) +jinit_memory_mgr (j_common_ptr cinfo) +{ + my_mem_ptr mem; + long max_to_use; + int pool; + size_t test_mac; + + cinfo->mem = NULL; /* for safety if init fails */ + + /* Check for configuration errors. + * SIZEOF(ALIGN_TYPE) should be a power of 2; otherwise, it probably + * doesn't reflect any real hardware alignment requirement. + * The test is a little tricky: for X>0, X and X-1 have no one-bits + * in common if and only if X is a power of 2, ie has only one one-bit. + * Some compilers may give an "unreachable code" warning here; ignore it. + */ + if ((SIZEOF(ALIGN_TYPE) & (SIZEOF(ALIGN_TYPE)-1)) != 0) + ERREXIT(cinfo, JERR_BAD_ALIGN_TYPE); + /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be + * a multiple of SIZEOF(ALIGN_TYPE). + * Again, an "unreachable code" warning may be ignored here. + * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK. + */ + test_mac = (size_t) MAX_ALLOC_CHUNK; + if ((long) test_mac != MAX_ALLOC_CHUNK || + (MAX_ALLOC_CHUNK % SIZEOF(ALIGN_TYPE)) != 0) + ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK); + + max_to_use = jpeg_mem_init(cinfo); /* system-dependent initialization */ + + /* Attempt to allocate memory manager's control block */ + mem = (my_mem_ptr) jpeg_get_small(cinfo, SIZEOF(my_memory_mgr)); + + if (mem == NULL) { + jpeg_mem_term(cinfo); /* system-dependent cleanup */ + ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 0); + } + + /* OK, fill in the method pointers */ + mem->pub.alloc_small = alloc_small; + mem->pub.alloc_large = alloc_large; + mem->pub.alloc_sarray = alloc_sarray; + mem->pub.alloc_barray = alloc_barray; + mem->pub.request_virt_sarray = request_virt_sarray; + mem->pub.request_virt_barray = request_virt_barray; + mem->pub.realize_virt_arrays = realize_virt_arrays; + mem->pub.access_virt_sarray = access_virt_sarray; + mem->pub.access_virt_barray = access_virt_barray; + mem->pub.free_pool = free_pool; + mem->pub.self_destruct = self_destruct; + + /* Make MAX_ALLOC_CHUNK accessible to other modules */ + mem->pub.max_alloc_chunk = MAX_ALLOC_CHUNK; + + /* Initialize working state */ + mem->pub.max_memory_to_use = max_to_use; + + for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) { + mem->small_list[pool] = NULL; + mem->large_list[pool] = NULL; + } + mem->virt_sarray_list = NULL; + mem->virt_barray_list = NULL; + + mem->total_space_allocated = SIZEOF(my_memory_mgr); + + /* Declare ourselves open for business */ + cinfo->mem = & mem->pub; + + /* Check for an environment variable JPEGMEM; if found, override the + * default max_memory setting from jpeg_mem_init. Note that the + * surrounding application may again override this value. + * If your system doesn't support getenv(), define NO_GETENV to disable + * this feature. + */ +#ifndef NO_GETENV + { char * memenv; + + if ((memenv = getenv("JPEGMEM")) != NULL) { + char ch = 'x'; + + if (sscanf(memenv, "%ld%c", &max_to_use, &ch) > 0) { + if (ch == 'm' || ch == 'M') + max_to_use *= 1000L; + mem->pub.max_memory_to_use = max_to_use * 1000L; + } + } + } +#endif + +} |