diff options
Diffstat (limited to 'plugins/FreeImage/Source/LibJPEG/jmemmgr.c')
| -rw-r--r-- | plugins/FreeImage/Source/LibJPEG/jmemmgr.c | 2237 | 
1 files changed, 1119 insertions, 1118 deletions
diff --git a/plugins/FreeImage/Source/LibJPEG/jmemmgr.c b/plugins/FreeImage/Source/LibJPEG/jmemmgr.c index b636f1be5c..f0e83fb950 100644 --- a/plugins/FreeImage/Source/LibJPEG/jmemmgr.c +++ b/plugins/FreeImage/Source/LibJPEG/jmemmgr.c @@ -1,1118 +1,1119 @@ -/*
 - * 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
 -
 -}
 +/* + * jmemmgr.c + * + * Copyright (C) 1991-1997, Thomas G. Lane. + * Modified 2011 by Guido Vollbeding. + * 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) { +	FMEMZERO((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) { +	FMEMZERO((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 + +}  | 
