libjpeg update

git-svn-id: http://svn.miranda-ng.org/main/trunk@5843 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c

1 files changed, 1119 insertions, 1119 deletions

diff --git a/plugins/AdvaImg/src/LibJPEG/jmemmgr.c b/plugins/AdvaImg/src/LibJPEG/jmemmgr.c
index f0e83fb950..ea9342022c 100644
--- a/plugins/AdvaImg/src/LibJPEG/jmemmgr.c
+++ b/plugins/AdvaImg/src/LibJPEG/jmemmgr.c
@@ -1,1119 +1,1119 @@
-/*
- * 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
-
-}
+/*

+ * jmemmgr.c

+ *

+ * Copyright (C) 1991-1997, Thomas G. Lane.

+ * Modified 2011-2012 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(noreturn_t)

+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

+

+}