diff options
Diffstat (limited to 'plugins/FreeImage/Source/LibJPEG/jmemmgr.c')
| -rw-r--r-- | plugins/FreeImage/Source/LibJPEG/jmemmgr.c | 1118 | 
1 files changed, 1118 insertions, 0 deletions
diff --git a/plugins/FreeImage/Source/LibJPEG/jmemmgr.c b/plugins/FreeImage/Source/LibJPEG/jmemmgr.c new file mode 100644 index 0000000000..b636f1be5c --- /dev/null +++ b/plugins/FreeImage/Source/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
 +
 +}
  | 
