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pdf-write.c
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pdf-write.c
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#include "mupdf/fitz.h"
#include "mupdf/pdf.h"
#include <zlib.h>
#include <assert.h>
#include <limits.h>
#include <string.h>
#include <stdio.h> /* for debug printing */
/* #define DEBUG_LINEARIZATION */
/* #define DEBUG_HEAP_SORT */
/* #define DEBUG_WRITING */
#define SIG_EXTRAS_SIZE (1024)
#define SLASH_BYTE_RANGE ("/ByteRange")
#define SLASH_CONTENTS ("/Contents")
#define SLASH_FILTER ("/Filter")
/*
As part of linearization, we need to keep a list of what objects are used
by what page. We do this by recording the objects used in a given page
in a page_objects structure. We have a list of these structures (one per
page) in the page_objects_list structure.
The page_objects structure maintains a heap in the object array, so
insertion takes log n time, and we can heapsort and dedupe at the end for
a total worse case n log n time.
The magic heap invariant is that:
entry[n] >= entry[(n+1)*2-1] & entry[n] >= entry[(n+1)*2]
or equivalently:
entry[(n-1)>>1] >= entry[n]
For a discussion of the heap data structure (and heapsort) see Kingston,
"Algorithms and Data Structures".
*/
typedef struct {
int num_shared;
int page_object_number;
int num_objects;
int min_ofs;
int max_ofs;
/* Extensible list of objects used on this page */
int cap;
int len;
int object[1];
} page_objects;
typedef struct {
int cap;
int len;
page_objects *page[1];
} page_objects_list;
typedef struct
{
fz_output *out;
int do_incremental;
int do_tight;
int do_ascii;
int do_expand;
int do_compress;
int do_compress_images;
int do_compress_fonts;
int do_garbage;
int do_linear;
int do_clean;
int do_encrypt;
int dont_regenerate_id;
int list_len;
int *use_list;
int64_t *ofs_list;
int *gen_list;
int *renumber_map;
/* The following extras are required for linearization */
int *rev_renumber_map;
int start;
int64_t first_xref_offset;
int64_t main_xref_offset;
int64_t first_xref_entry_offset;
int64_t file_len;
int hints_shared_offset;
int hintstream_len;
pdf_obj *linear_l;
pdf_obj *linear_h0;
pdf_obj *linear_h1;
pdf_obj *linear_o;
pdf_obj *linear_e;
pdf_obj *linear_n;
pdf_obj *linear_t;
pdf_obj *hints_s;
pdf_obj *hints_length;
int page_count;
page_objects_list *page_object_lists;
int crypt_object_number;
char opwd_utf8[128];
char upwd_utf8[128];
int permissions;
pdf_crypt *crypt;
} pdf_write_state;
/*
* Constants for use with use_list.
*
* If use_list[num] = 0, then object num is unused.
* If use_list[num] & PARAMS, then object num is the linearisation params obj.
* If use_list[num] & CATALOGUE, then object num is used by the catalogue.
* If use_list[num] & PAGE1, then object num is used by page 1.
* If use_list[num] & SHARED, then object num is shared between pages.
* If use_list[num] & PAGE_OBJECT then this must be the first object in a page.
* If use_list[num] & OTHER_OBJECTS then this must should appear in section 9.
* Otherwise object num is used by page (use_list[num]>>USE_PAGE_SHIFT).
*/
enum
{
USE_CATALOGUE = 2,
USE_PAGE1 = 4,
USE_SHARED = 8,
USE_PARAMS = 16,
USE_HINTS = 32,
USE_PAGE_OBJECT = 64,
USE_OTHER_OBJECTS = 128,
USE_PAGE_MASK = ~255,
USE_PAGE_SHIFT = 8
};
static void
expand_lists(fz_context *ctx, pdf_write_state *opts, int num)
{
int i;
/* objects are numbered 0..num and maybe two additional objects for linearization */
num += 3;
if (num <= opts->list_len)
return;
opts->use_list = fz_realloc_array(ctx, opts->use_list, num, int);
opts->ofs_list = fz_realloc_array(ctx, opts->ofs_list, num, int64_t);
opts->gen_list = fz_realloc_array(ctx, opts->gen_list, num, int);
opts->renumber_map = fz_realloc_array(ctx, opts->renumber_map, num, int);
opts->rev_renumber_map = fz_realloc_array(ctx, opts->rev_renumber_map, num, int);
for (i = opts->list_len; i < num; i++)
{
opts->use_list[i] = 0;
opts->ofs_list[i] = 0;
opts->gen_list[i] = 0;
opts->renumber_map[i] = i;
opts->rev_renumber_map[i] = i;
}
opts->list_len = num;
}
/*
* page_objects and page_object_list handling functions
*/
static page_objects_list *
page_objects_list_create(fz_context *ctx)
{
page_objects_list *pol = fz_calloc(ctx, 1, sizeof(*pol));
pol->cap = 1;
pol->len = 0;
return pol;
}
static void
page_objects_list_destroy(fz_context *ctx, page_objects_list *pol)
{
int i;
if (!pol)
return;
for (i = 0; i < pol->len; i++)
{
fz_free(ctx, pol->page[i]);
}
fz_free(ctx, pol);
}
static void
page_objects_list_ensure(fz_context *ctx, page_objects_list **pol, int newcap)
{
int oldcap = (*pol)->cap;
if (newcap <= oldcap)
return;
*pol = fz_realloc(ctx, *pol, sizeof(page_objects_list) + (newcap-1)*sizeof(page_objects *));
memset(&(*pol)->page[oldcap], 0, (newcap-oldcap)*sizeof(page_objects *));
(*pol)->cap = newcap;
}
static page_objects *
page_objects_create(fz_context *ctx)
{
int initial_cap = 8;
page_objects *po = fz_calloc(ctx, 1, sizeof(*po) + (initial_cap-1) * sizeof(int));
po->cap = initial_cap;
po->len = 0;
return po;
}
static void
page_objects_insert(fz_context *ctx, page_objects **ppo, int i)
{
page_objects *po;
/* Make a page_objects if we don't have one */
if (*ppo == NULL)
*ppo = page_objects_create(ctx);
po = *ppo;
/* page_objects insertion: extend the page_objects by 1, and put us on the end */
if (po->len == po->cap)
{
po = fz_realloc(ctx, po, sizeof(page_objects) + (po->cap*2 - 1)*sizeof(int));
po->cap *= 2;
*ppo = po;
}
po->object[po->len++] = i;
}
static void
page_objects_list_insert(fz_context *ctx, pdf_write_state *opts, int page, int object)
{
page_objects_list_ensure(ctx, &opts->page_object_lists, page+1);
if (object >= opts->list_len)
expand_lists(ctx, opts, object);
if (opts->page_object_lists->len < page+1)
opts->page_object_lists->len = page+1;
page_objects_insert(ctx, &opts->page_object_lists->page[page], object);
}
static void
page_objects_list_set_page_object(fz_context *ctx, pdf_write_state *opts, int page, int object)
{
page_objects_list_ensure(ctx, &opts->page_object_lists, page+1);
if (object >= opts->list_len)
expand_lists(ctx, opts, object);
opts->page_object_lists->page[page]->page_object_number = object;
}
static void
page_objects_sort(fz_context *ctx, page_objects *po)
{
int i, j;
int n = po->len;
/* Step 1: Make a heap */
/* Invariant: Valid heap in [0..i), unsorted elements in [i..n) */
for (i = 1; i < n; i++)
{
/* Now bubble backwards to maintain heap invariant */
j = i;
while (j != 0)
{
int tmp;
int k = (j-1)>>1;
if (po->object[k] >= po->object[j])
break;
tmp = po->object[k];
po->object[k] = po->object[j];
po->object[j] = tmp;
j = k;
}
}
/* Step 2: Heap sort */
/* Invariant: valid heap in [0..i), sorted list in [i..n) */
/* Initially: i = n */
for (i = n-1; i > 0; i--)
{
/* Swap the maximum (0th) element from the page_objects into its place
* in the sorted list (position i). */
int tmp = po->object[0];
po->object[0] = po->object[i];
po->object[i] = tmp;
/* Now, the page_objects is invalid because the 0th element is out
* of place. Bubble it until the page_objects is valid. */
j = 0;
while (1)
{
/* Children are k and k+1 */
int k = (j+1)*2-1;
/* If both children out of the page_objects, we're done */
if (k > i-1)
break;
/* If both are in the page_objects, pick the larger one */
if (k < i-1 && po->object[k] < po->object[k+1])
k++;
/* If j is bigger than k (i.e. both of its children),
* we're done */
if (po->object[j] > po->object[k])
break;
tmp = po->object[k];
po->object[k] = po->object[j];
po->object[j] = tmp;
j = k;
}
}
}
static int
order_ge(int ui, int uj)
{
/*
For linearization, we need to order the sections as follows:
Remaining pages (Part 7)
Shared objects (Part 8)
Objects not associated with any page (Part 9)
Any "other" objects
(Header)(Part 1)
(Linearization params) (Part 2)
(1st page Xref/Trailer) (Part 3)
Catalogue (and other document level objects) (Part 4)
First page (Part 6)
(Primary Hint stream) (*) (Part 5)
Any free objects
Note, this is NOT the same order they appear in
the final file!
(*) The PDF reference gives us the option of putting the hint stream
after the first page, and we take it, for simplicity.
*/
/* If the 2 objects are in the same section, then page object comes first. */
if (((ui ^ uj) & ~USE_PAGE_OBJECT) == 0)
return ((ui & USE_PAGE_OBJECT) == 0);
/* Put unused objects last */
else if (ui == 0)
return 1;
else if (uj == 0)
return 0;
/* Put the hint stream before that... */
else if (ui & USE_HINTS)
return 1;
else if (uj & USE_HINTS)
return 0;
/* Put page 1 before that... */
else if (ui & USE_PAGE1)
return 1;
else if (uj & USE_PAGE1)
return 0;
/* Put the catalogue before that... */
else if (ui & USE_CATALOGUE)
return 1;
else if (uj & USE_CATALOGUE)
return 0;
/* Put the linearization params before that... */
else if (ui & USE_PARAMS)
return 1;
else if (uj & USE_PARAMS)
return 0;
/* Put other objects before that */
else if (ui & USE_OTHER_OBJECTS)
return 1;
else if (uj & USE_OTHER_OBJECTS)
return 0;
/* Put shared objects before that... */
else if (ui & USE_SHARED)
return 1;
else if (uj & USE_SHARED)
return 0;
/* And otherwise, order by the page number on which
* they are used. */
return (ui>>USE_PAGE_SHIFT) >= (uj>>USE_PAGE_SHIFT);
}
static void
heap_sort(int *list, int n, const int *val, int (*ge)(int, int))
{
int i, j;
#ifdef DEBUG_HEAP_SORT
fprintf(stderr, "Initially:\n");
for (i=0; i < n; i++)
{
fprintf(stderr, "%d: %d %x\n", i, list[i], val[list[i]]);
}
#endif
/* Step 1: Make a heap */
/* Invariant: Valid heap in [0..i), unsorted elements in [i..n) */
for (i = 1; i < n; i++)
{
/* Now bubble backwards to maintain heap invariant */
j = i;
while (j != 0)
{
int tmp;
int k = (j-1)>>1;
if (ge(val[list[k]], val[list[j]]))
break;
tmp = list[k];
list[k] = list[j];
list[j] = tmp;
j = k;
}
}
#ifdef DEBUG_HEAP_SORT
fprintf(stderr, "Valid heap:\n");
for (i=0; i < n; i++)
{
int k;
fprintf(stderr, "%d: %d %x ", i, list[i], val[list[i]]);
k = (i+1)*2-1;
if (k < n)
{
if (ge(val[list[i]], val[list[k]]))
fprintf(stderr, "OK ");
else
fprintf(stderr, "BAD ");
}
if (k+1 < n)
{
if (ge(val[list[i]], val[list[k+1]]))
fprintf(stderr, "OK\n");
else
fprintf(stderr, "BAD\n");
}
else
fprintf(stderr, "\n");
}
#endif
/* Step 2: Heap sort */
/* Invariant: valid heap in [0..i), sorted list in [i..n) */
/* Initially: i = n */
for (i = n-1; i > 0; i--)
{
/* Swap the maximum (0th) element from the page_objects into its place
* in the sorted list (position i). */
int tmp = list[0];
list[0] = list[i];
list[i] = tmp;
/* Now, the page_objects is invalid because the 0th element is out
* of place. Bubble it until the page_objects is valid. */
j = 0;
while (1)
{
/* Children are k and k+1 */
int k = (j+1)*2-1;
/* If both children out of the page_objects, we're done */
if (k > i-1)
break;
/* If both are in the page_objects, pick the larger one */
if (k < i-1 && ge(val[list[k+1]], val[list[k]]))
k++;
/* If j is bigger than k (i.e. both of its children),
* we're done */
if (ge(val[list[j]], val[list[k]]))
break;
tmp = list[k];
list[k] = list[j];
list[j] = tmp;
j = k;
}
}
#ifdef DEBUG_HEAP_SORT
fprintf(stderr, "Sorted:\n");
for (i=0; i < n; i++)
{
fprintf(stderr, "%d: %d %x ", i, list[i], val[list[i]]);
if (i+1 < n)
{
if (ge(val[list[i+1]], val[list[i]]))
fprintf(stderr, "OK");
else
fprintf(stderr, "BAD");
}
fprintf(stderr, "\n");
}
#endif
}
static void
page_objects_dedupe(fz_context *ctx, page_objects *po)
{
int i, j;
int n = po->len-1;
for (i = 0; i < n; i++)
{
if (po->object[i] == po->object[i+1])
break;
}
j = i; /* j points to the last valid one */
i++; /* i points to the first one we haven't looked at */
for (; i < n; i++)
{
if (po->object[j] != po->object[i])
po->object[++j] = po->object[i];
}
po->len = j+1;
}
static void
page_objects_list_sort_and_dedupe(fz_context *ctx, page_objects_list *pol)
{
int i;
int n = pol->len;
for (i = 0; i < n; i++)
{
page_objects_sort(ctx, pol->page[i]);
page_objects_dedupe(ctx, pol->page[i]);
}
}
#ifdef DEBUG_LINEARIZATION
static void
page_objects_dump(pdf_write_state *opts)
{
page_objects_list *pol = opts->page_object_lists;
int i, j;
for (i = 0; i < pol->len; i++)
{
page_objects *p = pol->page[i];
fprintf(stderr, "Page %d\n", i+1);
for (j = 0; j < p->len; j++)
{
int o = p->object[j];
fprintf(stderr, "\tObject %d: use=%x\n", o, opts->use_list[o]);
}
fprintf(stderr, "Byte range=%d->%d\n", p->min_ofs, p->max_ofs);
fprintf(stderr, "Number of objects=%d, Number of shared objects=%d\n", p->num_objects, p->num_shared);
fprintf(stderr, "Page object number=%d\n", p->page_object_number);
}
}
static void
objects_dump(fz_context *ctx, pdf_document *doc, pdf_write_state *opts)
{
int i;
for (i=0; i < pdf_xref_len(ctx, doc); i++)
{
fprintf(stderr, "Object %d use=%x offset=%d\n", i, opts->use_list[i], (int)opts->ofs_list[i]);
}
}
#endif
/*
* Garbage collect objects not reachable from the trailer.
*/
/* Mark a reference. If it's been marked already, return NULL (as no further
* processing is required). If it's not, return the resolved object so
* that we can continue our recursive marking. If it's a duff reference
* return the fact so that we can remove the reference at source.
*/
static pdf_obj *markref(fz_context *ctx, pdf_document *doc, pdf_write_state *opts, pdf_obj *obj, int *duff)
{
int num = pdf_to_num(ctx, obj);
if (num <= 0 || num >= pdf_xref_len(ctx, doc))
{
*duff = 1;
return NULL;
}
*duff = 0;
if (opts->use_list[num])
return NULL;
opts->use_list[num] = 1;
/* Bake in /Length in stream objects */
fz_try(ctx)
{
if (pdf_obj_num_is_stream(ctx, doc, num))
{
pdf_obj *len = pdf_dict_get(ctx, obj, PDF_NAME(Length));
if (pdf_is_indirect(ctx, len))
{
opts->use_list[pdf_to_num(ctx, len)] = 0;
len = pdf_resolve_indirect(ctx, len);
pdf_dict_put(ctx, obj, PDF_NAME(Length), len);
}
}
}
fz_catch(ctx)
{
/* Leave broken */
}
obj = pdf_resolve_indirect(ctx, obj);
if (obj == NULL || pdf_is_null(ctx, obj))
{
*duff = 1;
opts->use_list[num] = 0;
}
return obj;
}
#ifdef DEBUG_MARK_AND_SWEEP
static int depth = 0;
static
void indent()
{
while (depth > 0)
{
int d = depth;
if (d > 16)
d = 16;
printf("%s", &" "[16-d]);
depth -= d;
}
}
#define DEBUGGING_MARKING(A) do { A; } while (0)
#else
#define DEBUGGING_MARKING(A) do { } while (0)
#endif
/* Recursively mark an object. If any references found are duff, then
* replace them with nulls. */
static int markobj(fz_context *ctx, pdf_document *doc, pdf_write_state *opts, pdf_obj *obj)
{
int i;
DEBUGGING_MARKING(depth++);
while (pdf_is_indirect(ctx, obj))
{
int duff;
DEBUGGING_MARKING(indent(); printf("Marking object %d\n", pdf_to_num(ctx, obj)));
obj = markref(ctx, doc, opts, obj, &duff);
if (duff)
{
DEBUGGING_MARKING(depth--);
return 1;
}
}
if (pdf_is_dict(ctx, obj))
{
int n = pdf_dict_len(ctx, obj);
for (i = 0; i < n; i++)
{
DEBUGGING_MARKING(indent(); printf("DICT[%d/%d] = %s\n", i, n, pdf_to_name(ctx, pdf_dict_get_key(ctx, obj, i))));
if (markobj(ctx, doc, opts, pdf_dict_get_val(ctx, obj, i)))
pdf_dict_put_val_null(ctx, obj, i);
}
}
else if (pdf_is_array(ctx, obj))
{
int n = pdf_array_len(ctx, obj);
for (i = 0; i < n; i++)
{
DEBUGGING_MARKING(indent(); printf("ARRAY[%d/%d]\n", i, n));
if (markobj(ctx, doc, opts, pdf_array_get(ctx, obj, i)))
pdf_array_put(ctx, obj, i, PDF_NULL);
}
}
DEBUGGING_MARKING(depth--);
return 0;
}
/*
* Scan for and remove duplicate objects (slow)
*/
static void removeduplicateobjs(fz_context *ctx, pdf_document *doc, pdf_write_state *opts)
{
int num, other, max_num;
int xref_len = pdf_xref_len(ctx, doc);
for (num = 1; num < xref_len; num++)
{
/* Only compare an object to objects preceding it */
for (other = 1; other < num; other++)
{
pdf_obj *a, *b;
int newnum, streama = 0, streamb = 0, differ = 0;
if (num == other || !opts->use_list[num] || !opts->use_list[other])
continue;
/* TODO: resolve indirect references to see if we can omit them */
/*
* Comparing stream objects data contents would take too long.
*
* pdf_obj_num_is_stream calls pdf_cache_object and ensures
* that the xref table has the objects loaded.
*/
fz_try(ctx)
{
streama = pdf_obj_num_is_stream(ctx, doc, num);
streamb = pdf_obj_num_is_stream(ctx, doc, other);
differ = streama || streamb;
if (streama && streamb && opts->do_garbage >= 4)
differ = 0;
}
fz_catch(ctx)
{
/* Assume different */
differ = 1;
}
if (differ)
continue;
a = pdf_get_xref_entry(ctx, doc, num)->obj;
b = pdf_get_xref_entry(ctx, doc, other)->obj;
if (pdf_objcmp(ctx, a, b))
continue;
if (streama && streamb)
{
/* Check to see if streams match too. */
fz_buffer *sa = NULL;
fz_buffer *sb = NULL;
fz_var(sa);
fz_var(sb);
differ = 1;
fz_try(ctx)
{
unsigned char *dataa, *datab;
size_t lena, lenb;
sa = pdf_load_raw_stream_number(ctx, doc, num);
sb = pdf_load_raw_stream_number(ctx, doc, other);
lena = fz_buffer_storage(ctx, sa, &dataa);
lenb = fz_buffer_storage(ctx, sb, &datab);
if (lena == lenb && memcmp(dataa, datab, lena) == 0)
differ = 0;
}
fz_always(ctx)
{
fz_drop_buffer(ctx, sa);
fz_drop_buffer(ctx, sb);
}
fz_catch(ctx)
{
fz_rethrow(ctx);
}
if (differ)
continue;
}
/* Keep the lowest numbered object */
newnum = fz_mini(num, other);
max_num = fz_maxi(num, other);
if (max_num >= opts->list_len)
expand_lists(ctx, opts, max_num);
opts->renumber_map[num] = newnum;
opts->renumber_map[other] = newnum;
opts->rev_renumber_map[newnum] = num; /* Either will do */
opts->use_list[fz_maxi(num, other)] = 0;
/* One duplicate was found, do not look for another */
break;
}
}
}
/*
* Renumber objects sequentially so the xref is more compact
*
* This code assumes that any opts->renumber_map[n] <= n for all n.
*/
static void compactxref(fz_context *ctx, pdf_document *doc, pdf_write_state *opts)
{
int num, newnum;
int xref_len = pdf_xref_len(ctx, doc);
/*
* Update renumber_map in-place, clustering all used
* objects together at low object ids. Objects that
* already should be renumbered will have their new
* object ids be updated to reflect the compaction.
*/
if (xref_len > opts->list_len)
expand_lists(ctx, opts, xref_len-1);
newnum = 1;
for (num = 1; num < xref_len; num++)
{
/* If it's not used, map it to zero */
if (!opts->use_list[opts->renumber_map[num]])
{
opts->renumber_map[num] = 0;
}
/* If it's not moved, compact it. */
else if (opts->renumber_map[num] == num)
{
opts->rev_renumber_map[newnum] = opts->rev_renumber_map[num];
opts->renumber_map[num] = newnum++;
}
/* Otherwise it's used, and moved. We know that it must have
* moved down, so the place it's moved to will be in the right
* place already. */
else
{
opts->renumber_map[num] = opts->renumber_map[opts->renumber_map[num]];
}
}
}
/*
* Update indirect objects according to renumbering established when
* removing duplicate objects and compacting the xref.
*/
static void renumberobj(fz_context *ctx, pdf_document *doc, pdf_write_state *opts, pdf_obj *obj)
{
int i;
int xref_len = pdf_xref_len(ctx, doc);
if (pdf_is_dict(ctx, obj))
{
int n = pdf_dict_len(ctx, obj);
for (i = 0; i < n; i++)
{
pdf_obj *key = pdf_dict_get_key(ctx, obj, i);
pdf_obj *val = pdf_dict_get_val(ctx, obj, i);
if (pdf_is_indirect(ctx, val))
{
int o = pdf_to_num(ctx, val);
if (o >= xref_len || o <= 0 || opts->renumber_map[o] == 0)
val = PDF_NULL;
else
val = pdf_new_indirect(ctx, doc, opts->renumber_map[o], 0);
pdf_dict_put_drop(ctx, obj, key, val);
}
else
{
renumberobj(ctx, doc, opts, val);
}
}
}
else if (pdf_is_array(ctx, obj))
{
int n = pdf_array_len(ctx, obj);
for (i = 0; i < n; i++)
{
pdf_obj *val = pdf_array_get(ctx, obj, i);
if (pdf_is_indirect(ctx, val))
{
int o = pdf_to_num(ctx, val);
if (o >= xref_len || o <= 0 || opts->renumber_map[o] == 0)
val = PDF_NULL;
else
val = pdf_new_indirect(ctx, doc, opts->renumber_map[o], 0);
pdf_array_put_drop(ctx, obj, i, val);
}
else
{
renumberobj(ctx, doc, opts, val);
}
}
}
}
static void renumberobjs(fz_context *ctx, pdf_document *doc, pdf_write_state *opts)
{
pdf_xref_entry *newxref = NULL;
int newlen;
int num;
int *new_use_list;
int xref_len = pdf_xref_len(ctx, doc);
new_use_list = fz_calloc(ctx, pdf_xref_len(ctx, doc)+3, sizeof(int));
fz_var(newxref);
fz_try(ctx)
{
/* Apply renumber map to indirect references in all objects in xref */
renumberobj(ctx, doc, opts, pdf_trailer(ctx, doc));
for (num = 0; num < xref_len; num++)
{
pdf_obj *obj;
int to = opts->renumber_map[num];
/* If object is going to be dropped, don't bother renumbering */
if (to == 0)
continue;
obj = pdf_get_xref_entry(ctx, doc, num)->obj;
if (pdf_is_indirect(ctx, obj))
{
obj = pdf_new_indirect(ctx, doc, to, 0);
fz_try(ctx)
pdf_update_object(ctx, doc, num, obj);
fz_always(ctx)
pdf_drop_obj(ctx, obj);
fz_catch(ctx)
fz_rethrow(ctx);
}
else
{
renumberobj(ctx, doc, opts, obj);
}
}
/* Create new table for the reordered, compacted xref */
newxref = Memento_label(fz_malloc_array(ctx, xref_len + 3, pdf_xref_entry), "pdf_xref_entries");
newxref[0] = *pdf_get_xref_entry(ctx, doc, 0);
/* Move used objects into the new compacted xref */
newlen = 0;
for (num = 1; num < xref_len; num++)
{
if (opts->use_list[num])
{
pdf_xref_entry *e;
if (newlen < opts->renumber_map[num])
newlen = opts->renumber_map[num];
e = pdf_get_xref_entry(ctx, doc, num);
newxref[opts->renumber_map[num]] = *e;
if (e->obj)
{
pdf_set_obj_parent(ctx, e->obj, opts->renumber_map[num]);
e->obj = NULL;
}
new_use_list[opts->renumber_map[num]] = opts->use_list[num];
}
else
{
pdf_xref_entry *e = pdf_get_xref_entry(ctx, doc, num);
pdf_drop_obj(ctx, e->obj);
e->obj = NULL;
fz_drop_buffer(ctx, e->stm_buf);
e->stm_buf = NULL;
}
}
pdf_replace_xref(ctx, doc, newxref, newlen + 1);
newxref = NULL;
}
fz_catch(ctx)
{
fz_free(ctx, newxref);
fz_free(ctx, new_use_list);
fz_rethrow(ctx);
}
fz_free(ctx, opts->use_list);
opts->use_list = new_use_list;
for (num = 1; num < xref_len; num++)
{
opts->renumber_map[num] = num;
}
}
static void page_objects_list_renumber(pdf_write_state *opts)
{
int i, j;
for (i = 0; i < opts->page_object_lists->len; i++)
{
page_objects *po = opts->page_object_lists->page[i];
for (j = 0; j < po->len; j++)
{
po->object[j] = opts->renumber_map[po->object[j]];
}
po->page_object_number = opts->renumber_map[po->page_object_number];
}
}
static void
swap_indirect_obj(fz_context *ctx, pdf_document *doc, pdf_write_state *opts, pdf_obj **obj)
{
pdf_obj *o = pdf_new_indirect(ctx, doc, opts->renumber_map[pdf_to_num(ctx, *obj)], 0);
pdf_drop_obj(ctx, *obj);
*obj = o;
}
static void
renumber_pages(fz_context *ctx, pdf_document *doc, pdf_write_state *opts)
{
fz_page *page;
for (page = doc->super.open; page != NULL; page = page->next)
{
pdf_page *ppage = (pdf_page *)page;
pdf_annot *annot;
swap_indirect_obj(ctx, doc, opts, &ppage->obj);
for (annot = ppage->annots; annot != NULL; annot = annot->next)