path: root/pdf/pdf_write.c

#include "fitz-internal.h"
#include "mupdf-internal.h"

/* #define DEBUG_LINEARIZATION */
/* #define DEBUG_HEAP_SORT */
/* #define DEBUG_WRITING */


typedef struct pdf_write_options_s pdf_write_options;

/*
	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;

struct pdf_write_options_s
{
	FILE *out;
	int do_ascii;
	int do_expand;
	int do_garbage;
	int do_linear;
	int *use_list;
	int *ofs_list;
	int *gen_list;
	int *renumber_map;
	int continue_on_error;
	int *errors;
	/* The following extras are required for linearization */
	int *rev_renumber_map;
	int *rev_gen_list;
	int start;
	int first_xref_offset;
	int main_xref_offset;
	int first_xref_entry_offset;
	int 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;
};

/*
 * 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.
 * 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_PAGE_MASK = ~127,
	USE_PAGE_SHIFT = 7
};

/*
 * 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_resize_array(ctx, *pol, 1, 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_resize_array(ctx, po, 1, 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_options *opts, int page, int object)
{
	page_objects_list_ensure(ctx, &opts->page_object_lists, page+1);
	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_options *opts, int page, int object)
{
	page_objects_list_ensure(ctx, &opts->page_object_lists, page+1);
	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 it's 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
		Shared objects
		Objects not associated with any page
		(Linearization params)
		Catalogue (and other document level objects)
		First page
		(Primary Hint stream) (*)
		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 calagoue 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 objects not associated with any page (anything
	 * not touched by the catalogue) before that... */
	else if (ui == 0)
		return 1;
	else if (uj == 0)
		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 it's 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_options *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(pdf_document *xref, pdf_write_options *opts)
{
	int i;

	for (i=0; i < xref->len; i++)
	{
		fprintf(stderr, "Object %d use=%x offset=%d\n", i, opts->use_list[i], opts->ofs_list[i]);
	}
}
#endif

/*
 * Garbage collect objects not reachable from the trailer.
 */

static pdf_obj *sweepref(pdf_document *xref, pdf_write_options *opts, pdf_obj *obj)
{
	int num = pdf_to_num(obj);
	int gen = pdf_to_gen(obj);
	fz_context *ctx = xref->ctx;

	if (num < 0 || num >= xref->len)
		return NULL;
	if (opts->use_list[num])
		return NULL;

	opts->use_list[num] = 1;

	/* Bake in /Length in stream objects */
	fz_try(ctx)
	{
		if (pdf_is_stream(xref, num, gen))
		{
			pdf_obj *len = pdf_dict_gets(obj, "Length");
			if (pdf_is_indirect(len))
			{
				opts->use_list[pdf_to_num(len)] = 0;
				len = pdf_resolve_indirect(len);
				pdf_dict_puts(obj, "Length", len);
			}
		}
	}
	fz_catch(ctx)
	{
		/* Leave broken */
	}

	return pdf_resolve_indirect(obj);
}

static void sweepobj(pdf_document *xref, pdf_write_options *opts, pdf_obj *obj)
{
	int i;

	if (pdf_is_indirect(obj))
		obj = sweepref(xref, opts, obj);

	if (pdf_is_dict(obj))
	{
		int n = pdf_dict_len(obj);
		for (i = 0; i < n; i++)
			sweepobj(xref, opts, pdf_dict_get_val(obj, i));
	}

	else if (pdf_is_array(obj))
	{
		int n = pdf_array_len(obj);
		for (i = 0; i < n; i++)
			sweepobj(xref, opts, pdf_array_get(obj, i));
	}
}

/*
 * Scan for and remove duplicate objects (slow)
 */

static void removeduplicateobjs(pdf_document *xref, pdf_write_options *opts)
{
	int num, other;
	fz_context *ctx = xref->ctx;

	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 differ, newnum;

			if (num == other || !opts->use_list[num] || !opts->use_list[other])
				continue;

			/*
			 * Comparing stream objects data contents would take too long.
			 *
			 * pdf_is_stream calls pdf_cache_object and ensures
			 * that the xref table has the objects loaded.
			 */
			fz_try(ctx)
			{
				differ = (pdf_is_stream(xref, num, 0) || pdf_is_stream(xref, other, 0));
			}
			fz_catch(ctx)
			{
				/* Assume different */
				differ = 1;
			}
			if (differ)
				continue;

			a = xref->table[num].obj;
			b = xref->table[other].obj;

			a = pdf_resolve_indirect(a);
			b = pdf_resolve_indirect(b);

			if (pdf_objcmp(a, b))
				continue;

			/* Keep the lowest numbered object */
			newnum = fz_mini(num, other);
			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(pdf_document *xref, pdf_write_options *opts)
{
	int num, newnum;

	/*
	 * 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.
	 */

	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->rev_gen_list[newnum] = opts->rev_gen_list[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(pdf_document *xref, pdf_write_options *opts, pdf_obj *obj)
{
	int i;
	fz_context *ctx = xref->ctx;

	if (pdf_is_dict(obj))
	{
		int n = pdf_dict_len(obj);
		for (i = 0; i < n; i++)
		{
			pdf_obj *key = pdf_dict_get_key(obj, i);
			pdf_obj *val = pdf_dict_get_val(obj, i);
			if (pdf_is_indirect(val))
			{
				val = pdf_new_indirect(ctx, opts->renumber_map[pdf_to_num(val)], 0, xref);
				pdf_dict_put(obj, key, val);
				pdf_drop_obj(val);
			}
			else
			{
				renumberobj(xref, opts, val);
			}
		}
	}

	else if (pdf_is_array(obj))
	{
		int n = pdf_array_len(obj);
		for (i = 0; i < n; i++)
		{
			pdf_obj *val = pdf_array_get(obj, i);
			if (pdf_is_indirect(val))
			{
				val = pdf_new_indirect(ctx, opts->renumber_map[pdf_to_num(val)], 0, xref);
				pdf_array_put(obj, i, val);
				pdf_drop_obj(val);
			}
			else
			{
				renumberobj(xref, opts, val);
			}
		}
	}
}

static void renumberobjs(pdf_document *xref, pdf_write_options *opts)
{
	pdf_xref_entry *oldxref;
	int newlen;
	int num;
	fz_context *ctx = xref->ctx;
	int *new_use_list;

	new_use_list = fz_calloc(ctx, xref->len+3, sizeof(int));

	fz_try(ctx)
	{
		/* Apply renumber map to indirect references in all objects in xref */
		renumberobj(xref, opts, xref->trailer);
		for (num = 0; num < xref->len; num++)
		{
			pdf_obj *obj = xref->table[num].obj;

			if (pdf_is_indirect(obj))
			{
				obj = pdf_new_indirect(ctx, opts->renumber_map[pdf_to_num(obj)], 0, xref);
				pdf_update_object(xref, num, obj);
				pdf_drop_obj(obj);
			}
			else
			{
				renumberobj(xref, opts, obj);
			}
		}

		/* Create new table for the reordered, compacted xref */
		oldxref = xref->table;
		xref->table = fz_malloc_array(ctx, xref->len + 3, sizeof(pdf_xref_entry));
		xref->table[0] = oldxref[0];

		/* Move used objects into the new compacted xref */
		newlen = 0;
		for (num = 1; num < xref->len; num++)
		{
			if (opts->use_list[num])
			{
				if (newlen < opts->renumber_map[num])
					newlen = opts->renumber_map[num];
				xref->table[opts->renumber_map[num]] = oldxref[num];
				new_use_list[opts->renumber_map[num]] = opts->use_list[num];
			}
			else
			{
				pdf_drop_obj(oldxref[num].obj);
			}
		}
	}
	fz_catch(ctx)
	{
		fz_free(ctx, new_use_list);
		fz_rethrow(ctx);
	}
	fz_free(ctx, oldxref);
	fz_free(ctx, opts->use_list);
	opts->use_list = new_use_list;

	/* Update the used objects count in compacted xref */
	xref->len = newlen + 1;

	for (num = 1; num < xref->len; num++)
	{
		opts->renumber_map[num] = num;
	}
}

static void page_objects_list_renumber(pdf_write_options *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
mark_all(pdf_document *xref, pdf_write_options *opts, pdf_obj *val, int flag, int page)
{
	fz_context *ctx = xref->ctx;

	if (pdf_dict_mark(val))
		return;

	fz_try(ctx)
	{
		if (pdf_is_indirect(val))
		{
			int num = pdf_to_num(val);
			if (flag >= 16 && (opts->use_list[num] & USE_PAGE_MASK))
				/* Already used */
				opts->use_list[num] |= USE_SHARED;
			else
				opts->use_list[num] |= flag;
			if (page >= 0)
				page_objects_list_insert(ctx, opts, page, num);
		}

		if (pdf_is_dict(val))
		{
			int i, n = pdf_dict_len(val);

			for (i = 0; i < n; i++)
			{
				mark_all(xref, opts, pdf_dict_get_val(val, i), flag, page);
			}
		}
		else if (pdf_is_array(val))
		{
			int i, n = pdf_array_len(val);

			for (i = 0; i < n; i++)
			{
				mark_all(xref, opts, pdf_array_get(val, i), flag, page);
			}
		}
	}
	fz_always(ctx)
	{
		pdf_dict_unmark(val);
	}
	fz_catch(ctx)
	{
		fz_rethrow(ctx);
	}
}

static int
mark_pages(pdf_document *xref, pdf_write_options *opts, pdf_obj *val, int pagenum)
{
	fz_context *ctx = xref->ctx;

	if (pdf_dict_mark(val))
		return pagenum;

	fz_try(ctx)
	{
		if (pdf_is_dict(val))
		{
			if (!strcmp("Page", pdf_to_name(pdf_dict_gets(val, "Type"))))
			{
				int num = pdf_to_num(val);
				pdf_dict_unmark(val);
				mark_all(xref, opts, val, pagenum == 0 ? USE_PAGE1 : (pagenum<<USE_PAGE_SHIFT), pagenum);
				page_objects_list_set_page_object(ctx, opts, pagenum, num);
				pagenum++;
				opts->use_list[num] |= USE_PAGE_OBJECT;
			}
			else
			{
				int i, n = pdf_dict_len(val);

				for (i = 0; i < n; i++)
				{
					pdf_obj *key = pdf_dict_get_key(val, i);
					pdf_obj *obj = pdf_dict_get_val(val, i);

					if (!strcmp("Kids", pdf_to_name(key)))
						pagenum = mark_pages(xref, opts, obj, pagenum);
					else
						mark_all(xref, opts, obj, USE_CATALOGUE, -1);
				}

				if (pdf_is_indirect(val))
				{
					int num = pdf_to_num(val);
					opts->use_list[num] |= USE_CATALOGUE;
				}
			}
		}
		else if (pdf_is_array(val))
		{
			int i, n = pdf_array_len(val);

			for (i = 0; i < n; i++)
			{
				pagenum = mark_pages(xref, opts, pdf_array_get(val, i), pagenum);
			}
			if (pdf_is_indirect(val))
			{
				int num = pdf_to_num(val);
				opts->use_list[num] |= USE_CATALOGUE;
			}
		}
	}
	fz_always(ctx)
	{
		pdf_dict_unmark(val);
	}
	fz_catch(ctx)
	{
		fz_rethrow(ctx);
	}
	return pagenum;
}

static void
mark_root(pdf_document *xref, pdf_write_options *opts, pdf_obj *dict)
{
	fz_context *ctx = xref->ctx;
	int i, n = pdf_dict_len(dict);

	if (pdf_dict_mark(dict))
		return;

	fz_try(ctx)
	{
		if (pdf_is_indirect(dict))
		{
			int num = pdf_to_num(dict);
			opts->use_list[num] |= USE_CATALOGUE;
		}

		for (i = 0; i < n; i++)
		{
			char *key = pdf_to_name(pdf_dict_get_key(dict, i));
			pdf_obj *val = pdf_dict_get_val(dict, i);

			if (!strcmp("Pages", key))
				opts->page_count = mark_pages(xref, opts, val, 0);
			else if (!strcmp("Outlines", key))
			{
				/* FIXME: Look at PageMode to decide whether to
				 * USE_OTHERPAGES or USE_PAGE1 here. */
				if (0 /* PageMode == "Outlines" */)
					mark_all(xref, opts, val, USE_PAGE1, -1);
			}
			else
				mark_all(xref, opts, val, USE_CATALOGUE, -1);
		}
	}
	fz_always(ctx)
	{
		pdf_dict_unmark(dict);
	}
	fz_catch(ctx)
	{
		fz_rethrow(ctx);
	}
}

static void
mark_trailer(pdf_document *xref, pdf_write_options *opts, pdf_obj *dict)
{
	fz_context *ctx = xref->ctx;
	int i, n = pdf_dict_len(dict);

	if (pdf_dict_mark(dict))
		return;

	fz_try(ctx)
	{
		for (i = 0; i < n; i++)
		{
			char *key = pdf_to_name(pdf_dict_get_key(dict, i));
			pdf_obj *val = pdf_dict_get_val(dict, i);

			if (!strcmp("Root", key))
				mark_root(xref, opts, val);
			else
				mark_all(xref, opts, val, USE_CATALOGUE, -1);
		}
	}
	fz_always(ctx)
	{
		pdf_dict_unmark(dict);
	}
	fz_catch(ctx)
	{
		fz_rethrow(ctx);
	}
}

static void
add_linearization_objs(pdf_document *xref, pdf_write_options *opts)
{
	pdf_obj *params_obj = NULL;
	pdf_obj *params_ref = NULL;
	pdf_obj *hint_obj = NULL;
	pdf_obj *hint_ref = NULL;
	pdf_obj *o = NULL;
	int params_num, hint_num;
	fz_context *ctx = xref->ctx;

	fz_var(params_obj);
	fz_var(params_ref);
	fz_var(hint_obj);
	fz_var(hint_ref);
	fz_var(o);

	fz_try(ctx)
	{
		/* Linearization params */
		params_obj = pdf_new_dict(ctx, 10);
		params_ref = pdf_new_ref(xref, params_obj);
		params_num = pdf_to_num(params_ref);

		opts->use_list[params_num] = USE_PARAMS;
		opts->renumber_map[params_num] = params_num;
		opts->rev_renumber_map[params_num] = params_num;
		opts->gen_list[params_num] = 0;
		opts->rev_gen_list[params_num] = 0;
		pdf_dict_puts_drop(params_obj, "Linearized", pdf_new_real(ctx, 1.0));
		opts->linear_l = pdf_new_int(ctx, INT_MIN);
		pdf_dict_puts(params_obj, "L", opts->linear_l);
		opts->linear_h0 = pdf_new_int(ctx, INT_MIN);
		o = pdf_new_array(ctx, 2);
		pdf_array_push(o, opts->linear_h0);
		opts->linear_h1 = pdf_new_int(ctx, INT_MIN);
		pdf_array_push(o, opts->linear_h1);
		pdf_dict_puts_drop(params_obj, "H", o);
		o = NULL;
		opts->linear_o = pdf_new_int(ctx, INT_MIN);
		pdf_dict_puts(params_obj, "O", opts->linear_o);
		opts->linear_e = pdf_new_int(ctx, INT_MIN);
		pdf_dict_puts(params_obj, "E", opts->linear_e);
		opts->linear_n = pdf_new_int(ctx, INT_MIN);
		pdf_dict_puts(params_obj, "N", opts->linear_n);
		opts->linear_t = pdf_new_int(ctx, INT_MIN);
		pdf_dict_puts(params_obj, "T", opts->linear_t);

		/* Primary hint stream */
		hint_obj = pdf_new_dict(ctx, 10);
		hint_ref = pdf_new_ref(xref, hint_obj);
		hint_num = pdf_to_num(hint_ref);

		opts->use_list[hint_num] = USE_HINTS;
		opts->renumber_map[hint_num] = hint_num;
		opts->rev_renumber_map[hint_num] = hint_num;
		opts->gen_list[hint_num] = 0;
		opts->rev_gen_list[hint_num] = 0;
		pdf_dict_puts_drop(hint_obj, "P", pdf_new_int(ctx, 0));
		opts->hints_s = pdf_new_int(ctx, INT_MIN);
		pdf_dict_puts(hint_obj, "S", opts->hints_s);
		/* FIXME: Do we have thumbnails? Do a T entry */
		/* FIXME: Do we have outlines? Do an O entry */
		/* FIXME: Do we have article threads? Do an A entry */
		/* FIXME: Do we have named destinations? Do a E entry */
		/* FIXME: Do we have interactive forms? Do a V entry */
		/* FIXME: Do we have document information? Do an I entry */
		/* FIXME: Do we have logical structure heirarchy? Do a C entry */
		/* FIXME: Do L, Page Label hint table */
		pdf_dict_puts_drop(hint_obj, "Filter", pdf_new_name(ctx, "FlateDecode"));
		opts->hints_length = pdf_new_int(ctx, INT_MIN);
		pdf_dict_puts(hint_obj, "Length", opts->hints_length);
		xref->table[hint_num].stm_ofs = -1;
	}
	fz_always(ctx)
	{
		pdf_drop_obj(params_obj);
		pdf_drop_obj(params_ref);
		pdf_drop_obj(hint_ref);
		pdf_drop_obj(hint_obj);
		pdf_drop_obj(o);
	}
	fz_catch(ctx)
	{
		fz_rethrow(ctx);
	}
}

static void
lpr_inherit_res_contents(fz_context *ctx, pdf_obj *res, pdf_obj *dict, char *text)
{
	pdf_obj *o, *r;
	int i, n;

	/* If the parent node doesn't have an entry of this type, give up. */
	o = pdf_dict_gets(dict, text);
	if (!o)
		return;

	/* If the resources dict we are building doesn't have an entry of this
	 * type yet, then just copy it (ensuring it's not a reference) */
	r = pdf_dict_gets(res, text);
	if (r == NULL)
	{
		o = pdf_resolve_indirect(o);
		if (pdf_is_dict(o))
			o = pdf_copy_dict(ctx, o);
		else if (pdf_is_array(o))
			o = pdf_copy_array(ctx, o);
		else
			o = NULL;
		if (o)
			pdf_dict_puts(res, text, o);
		return;
	}

	/* Otherwise we need to merge o into r */
	if (pdf_is_dict(o))
	{
		n = pdf_dict_len(o);
		for (i = 0; i < n; i++)
		{
			pdf_obj *key = pdf_dict_get_key(o, i);
			pdf_obj *val = pdf_dict_get_val(o, i);

			if (pdf_dict_gets(res, pdf_to_name(key)))
				continue;
			pdf_dict_puts(res, pdf_to_name(key), val);
		}
	}
}

static void
lpr_inherit_res(fz_context *ctx, pdf_obj *node, int depth, pdf_obj *dict)
{
	while (1)
	{
		pdf_obj *o;

		node = pdf_dict_gets(node, "Parent");
		depth--;
		if (!node || depth < 0)
			break;

		o = pdf_dict_gets(node, "Resources");
		if (o)
		{
			lpr_inherit_res_contents(ctx, dict, o, "ExtGState");
			lpr_inherit_res_contents(ctx, dict, o, "ColorSpace");
			lpr_inherit_res_contents(ctx, dict, o, "Pattern");
			lpr_inherit_res_contents(ctx, dict, o, "Shading");
			lpr_inherit_res_contents(ctx, dict, o, "XObject");
			lpr_inherit_res_contents(ctx, dict, o, "Font");
			lpr_inherit_res_contents(ctx, dict, o, "ProcSet");
			lpr_inherit_res_contents(ctx, dict, o, "Properties");
		}
	}
}

static pdf_obj *
lpr_inherit(fz_context *ctx, pdf_obj *node, char *text, int depth)
{
	do
	{
		pdf_obj *o = pdf_dict_gets(node, text);

		if (o)
			return pdf_resolve_indirect(o);
		node = pdf_dict_gets(node, "Parent");
		depth--;
	}
	while (depth >= 0 && node);

	return NULL;
}

static int
lpr(fz_context *ctx, pdf_obj *node, int depth, int page)
{
	pdf_obj *kids;
	pdf_obj *o = NULL;
	int i, n;

	if (pdf_dict_mark(node))
		return page;

	fz_var(o);

	fz_try(ctx)
	{
		if (!strcmp("Page", pdf_to_name(pdf_dict_gets(node, "Type"))))
		{
			pdf_obj *r; /* r is deliberately not cleaned up */

			/* Copy resources down to the child */
			o = pdf_keep_obj(pdf_dict_gets(node, "Resources"));
			if (!o)
			{
				o = pdf_keep_obj(pdf_new_dict(ctx, 2));
				pdf_dict_puts(node, "Resources", o);
			}
			lpr_inherit_res(ctx, node, depth, o);
			r = lpr_inherit(ctx, node, "MediaBox", depth);
			if (r)
				pdf_dict_puts(node, "MediaBox", r);
			r = lpr_inherit(ctx, node, "CropBox", depth);
			if (r)
				pdf_dict_puts(node, "CropBox", r);
			r = lpr_inherit(ctx, node, "BleedBox", depth);
			if (r)
				pdf_dict_puts(node, "BleedBox", r);
			r = lpr_inherit(ctx, node, "TrimBox", depth);
			if (r)
				pdf_dict_puts(node, "TrimBox", r);
			r = lpr_inherit(ctx, node, "ArtBox", depth);
			if (r)
				pdf_dict_puts(node, "ArtBox", r);
			r = lpr_inherit(ctx, node, "Rotate", depth);
			if (r)
				pdf_dict_puts(node, "Rotate", r);
			page++;
		}
		else
		{
			kids = pdf_dict_gets(node, "Kids");
			n = pdf_array_len(kids);
			for(i = 0; i < n; i++)
			{
				page = lpr(ctx, pdf_array_get(kids, i), depth+1, page);
			}
			pdf_dict_dels(node, "Resources");
			pdf_dict_dels(node, "MediaBox");
			pdf_dict_dels(node, "CropBox");
			pdf_dict_dels(node, "BleedBox");
			pdf_dict_dels(node, "TrimBox");
			pdf_dict_dels(node, "ArtBox");
			pdf_dict_dels(node, "Rotate");
		}
	}
	fz_always(ctx)
	{
		pdf_drop_obj(o);
	}
	fz_catch(ctx)
	{
		fz_rethrow(ctx);
	}

	pdf_dict_unmark(node);

	return page;
}

void
pdf_localise_page_resources(pdf_document *xref)
{
	fz_context *ctx = xref->ctx;

	if (xref->resources_localised)
		return;

	lpr(ctx, pdf_dict_getp(xref->trailer, "Root/Pages"), 0, 0);

	xref->resources_localised = 1;
}

static void
linearize(pdf_document *xref, pdf_write_options *opts)
{
	int i;
	int n = xref->len + 2;
	int *reorder;
	int *rev_renumber_map;
	int *rev_gen_list;
	fz_context *ctx = xref->ctx;

	opts->page_object_lists = page_objects_list_create(ctx);

	/* Ensure that every page has local references of its resources */
	/* FIXME: We could 'thin' the resources according to what is actually
	 * required for each page, but this would require us to run the page
	 * content streams. */
	pdf_localise_page_resources(xref);

	/* Walk the objects for each page, marking which ones are used, where */
	memset(opts->use_list, 0, n * sizeof(int));
	mark_trailer(xref, opts, xref->trailer);

	/* Add new objects required for linearization */
	add_linearization_objs(xref, opts);

#ifdef DEBUG_WRITING
	fprintf(stderr, "Usage calculated:\n");
	for (i=0; i < xref->len; i++)
	{
		fprintf(stderr, "%d: use=%d\n", i, opts->use_list[i]);
	}
#endif

	/* Allocate/init the structures used for renumbering the objects */
	reorder = fz_calloc(ctx, n, sizeof(int));
	rev_renumber_map = fz_calloc(ctx, n, sizeof(int));
	rev_gen_list = fz_calloc(ctx, n, sizeof(int));
	for (i = 0; i < n; i++)
	{
		reorder[i] = i;
	}

	/* Heap sort the reordering */
	heap_sort(reorder+1, n-1, opts->use_list, &order_ge);

#ifdef DEBUG_WRITING
	fprintf(stderr, "Reordered:\n");
	for (i=1; i < xref->len; i++)
	{
		fprintf(stderr, "%d: use=%d\n", i, opts->use_list[reorder[i]]);
	}
#endif

	/* Find the split point */
	for (i = 1; (opts->use_list[reorder[i]] & USE_PARAMS) == 0; i++);
	opts->start = i;

	/* Roll the reordering into the renumber_map */
	for (i = 0; i < n; i++)
	{
		opts->renumber_map[reorder[i]] = i;
		rev_renumber_map[i] = opts->rev_renumber_map[reorder[i]];
		rev_gen_list[i] = opts->rev_gen_list[reorder[i]];
	}
	fz_free(ctx, opts->rev_renumber_map);
	fz_free(ctx, opts->rev_gen_list);
	opts->rev_renumber_map = rev_renumber_map;
	opts->rev_gen_list = rev_gen_list;
	fz_free(ctx, reorder);

	/* Apply the renumber_map */
	page_objects_list_renumber(opts);
	renumberobjs(xref, opts);

	page_objects_list_sort_and_dedupe(ctx, opts->page_object_lists);
}

static void
update_linearization_params(pdf_document *xref, pdf_write_options *opts)
{
	int offset;
	pdf_set_int(opts->linear_l, opts->file_len);
	/* Primary hint stream offset (of object, not stream!) */
	pdf_set_int(opts->linear_h0, opts->ofs_list[xref->len-1]);
	/* Primary hint stream length (of object, not stream!) */
	offset = (opts->start == 1 ? opts->main_xref_offset : opts->ofs_list[1] + opts->hintstream_len);
	pdf_set_int(opts->linear_h1, offset - opts->ofs_list[xref->len-1]);
	/* Object number of first pages page object (the first object of page 0) */
	pdf_set_int(opts->linear_o, opts->page_object_lists->page[0]->object[0]);
	/* Offset of end of first page (first page is followed by primary
	 * hint stream (object n-1) then remaining pages (object 1...). The
	 * primary hint stream counts as part of the first pages data, I think.
	 */
	offset = (opts->start == 1 ? opts->main_xref_offset : opts->ofs_list[1] + opts->hintstream_len);
	pdf_set_int(opts->linear_e, offset);
	/* Number of pages in document */
	pdf_set_int(opts->linear_n, opts->page_count);
	/* Offset of first entry in main xref table */
	pdf_set_int(opts->linear_t, opts->first_xref_entry_offset + opts->hintstream_len);
	/* Offset of shared objects hint table in the primary hint stream */
	pdf_set_int(opts->hints_s, opts->hints_shared_offset);
	/* Primary hint stream length */
	pdf_set_int(opts->hints_length, opts->hintstream_len);
}


/*
 * Make sure we have loaded objects from object streams.
 */

static void preloadobjstms(pdf_document *xref)
{
	pdf_obj *obj;
	int num;

	for (num = 0; num < xref->len; num++)
	{
		if (xref->table[num].type == 'o')
		{
			obj = pdf_load_object(xref, num, 0);
			pdf_drop_obj(obj);
		}
	}
}

/*
 * Save streams and objects to the output
 */

static inline int isbinary(int c)
{
	if (c == '\n' || c == '\r' || c == '\t')
		return 0;
	return c < 32 || c > 127;
}

static int isbinarystream(fz_buffer *buf)
{
	int i;
	for (i = 0; i < buf->len; i++)
		if (isbinary(buf->data[i]))
			return 1;
	return 0;
}

static fz_buffer *hexbuf(fz_context *ctx, unsigned char *p, int n)
{
	static const char hex[16] = "0123456789abcdef";
	fz_buffer *buf;
	int x = 0;

	buf = fz_new_buffer(ctx, n * 2 + (n / 32) + 2);

	while (n--)
	{
		buf->data[buf->len++] = hex[*p >> 4];
		buf->data[buf->len++] = hex[*p & 15];
		if (++x == 32)
		{
			buf->data[buf->len++] = '\n';
			x = 0;
		}
		p++;
	}

	buf->data[buf->len++] = '>';
	buf->data[buf->len++] = '\n';

	return buf;
}

static void addhexfilter(pdf_document *xref, pdf_obj *dict)
{
	pdf_obj *f, *dp, *newf, *newdp;
	pdf_obj *ahx, *nullobj;
	fz_context *ctx = xref->ctx;

	ahx = pdf_new_name(ctx, "ASCIIHexDecode");
	nullobj = pdf_new_null(ctx);
	newf = newdp = NULL;

	f = pdf_dict_gets(dict, "Filter");
	dp = pdf_dict_gets(dict, "DecodeParms");

	if (pdf_is_name(f))
	{
		newf = pdf_new_array(ctx, 2);
		pdf_array_push(newf, ahx);
		pdf_array_push(newf, f);
		f = newf;
		if (pdf_is_dict(dp))
		{
			newdp = pdf_new_array(ctx, 2);
			pdf_array_push(newdp, nullobj);
			pdf_array_push(newdp, dp);
			dp = newdp;
		}
	}
	else if (pdf_is_array(f))
	{
		pdf_array_insert(f, ahx);
		if (pdf_is_array(dp))
			pdf_array_insert(dp, nullobj);
	}
	else
		f = ahx;

	pdf_dict_puts(dict, "Filter", f);
	if (dp)
		pdf_dict_puts(dict, "DecodeParms", dp);

	pdf_drop_obj(ahx);
	pdf_drop_obj(nullobj);
	pdf_drop_obj(newf);
	pdf_drop_obj(newdp);
}

static void copystream(pdf_document *xref, pdf_write_options *opts, pdf_obj *obj_orig, int num, int gen)
{
	fz_buffer *buf, *tmp;
	pdf_obj *newlen;
	pdf_obj *obj;
	fz_context *ctx = xref->ctx;
	int orig_num = opts->rev_renumber_map[num];
	int orig_gen = opts->rev_gen_list[num];

	buf = pdf_load_raw_renumbered_stream(xref, num, gen, orig_num, orig_gen);

	obj = pdf_copy_dict(ctx, obj_orig);
	if (opts->do_ascii && isbinarystream(buf))
	{
		tmp = hexbuf(ctx, buf->data, buf->len);
		fz_drop_buffer(ctx, buf);
		buf = tmp;

		addhexfilter(xref, obj);

		newlen = pdf_new_int(ctx, buf->len);
		pdf_dict_puts(obj, "Length", newlen);
		pdf_drop_obj(newlen);
	}

	fprintf(opts->out, "%d %d obj\n", num, gen);
	pdf_fprint_obj(opts->out, obj, opts->do_expand == 0);
	fprintf(opts->out, "stream\n");
	fwrite(buf->data, 1, buf->len, opts->out);
	fprintf(opts->out, "endstream\nendobj\n\n");

	fz_drop_buffer(ctx, buf);
	pdf_drop_obj(obj);
}

static void expandstream(pdf_document *xref, pdf_write_options *opts, pdf_obj *obj_orig, int num, int gen)
{
	fz_buffer *buf, *tmp;
	pdf_obj *newlen;
	pdf_obj *obj;
	fz_context *ctx = xref->ctx;
	int orig_num = opts->rev_renumber_map[num];
	int orig_gen = opts->rev_gen_list[num];
	int truncated = 0;

	buf = pdf_load_renumbered_stream(xref, num, gen, orig_num, orig_gen, (opts->continue_on_error ? &truncated : NULL));
	if (truncated && opts->errors)
		(*opts->errors)++;

	obj = pdf_copy_dict(ctx, obj_orig);
	pdf_dict_dels(obj, "Filter");
	pdf_dict_dels(obj, "DecodeParms");

	if (opts->do_ascii && isbinarystream(buf))
	{
		tmp = hexbuf(ctx, buf->data, buf->len);
		fz_drop_buffer(ctx, buf);
		buf = tmp;

		addhexfilter(xref, obj);
	}

	newlen = pdf_new_int(ctx, buf->len);
	pdf_dict_puts(obj, "Length", newlen);
	pdf_drop_obj(newlen);

	fprintf(opts->out, "%d %d obj\n", num, gen);
	pdf_fprint_obj(opts->out, obj, opts->do_expand == 0);
	fprintf(opts->out, "stream\n");
	fwrite(buf->data, 1, buf->len, opts->out);
	fprintf(opts->out, "endstream\nendobj\n\n");

	fz_drop_buffer(ctx, buf);
	pdf_drop_obj(obj);
}

static int is_image_filter(char *s)
{
	if (!strcmp(s, "CCITTFaxDecode") || !strcmp(s, "CCF") ||
		!strcmp(s, "DCTDecode") || !strcmp(s, "DCT") ||
		!strcmp(s, "RunLengthDecode") || !strcmp(s, "RL") ||
		!strcmp(s, "JBIG2Decode") ||
		!strcmp(s, "JPXDecode"))
		return 1;
	return 0;
}

static int filter_implies_image(pdf_document *xref, pdf_obj *o)
{
	if (!o)
		return 0;
	if (pdf_is_name(o))
		return is_image_filter(pdf_to_name(o));
	if (pdf_is_array(o))
	{
		int i, len;
		len = pdf_array_len(o);
		for (i = 0; i < len; i++)
			if (is_image_filter(pdf_to_name(pdf_array_get(o, i))))
				return 1;
	}
	return 0;
}

static void writeobject(pdf_document *xref, pdf_write_options *opts, int num, int gen)
{
	pdf_obj *obj;
	pdf_obj *type;
	fz_context *ctx = xref->ctx;

	fz_try(ctx)
	{
		obj = pdf_load_object(xref, num, gen);
	}
	fz_catch(ctx)
	{
		if (opts->continue_on_error)
		{
			fprintf(opts->out, "%d %d obj\nnull\nendobj\n", num, gen);
			if (opts->errors)
				(*opts->errors)++;
			fz_warn(ctx, "%s", fz_caught(ctx));
			return;
		}
		else
			fz_rethrow(ctx);
	}

	/* skip ObjStm and XRef objects */
	if (pdf_is_dict(obj))
	{
		type = pdf_dict_gets(obj, "Type");
		if (pdf_is_name(type) && !strcmp(pdf_to_name(type), "ObjStm"))
		{
			opts->use_list[num] = 0;
			pdf_drop_obj(obj);
			return;
		}
		if (pdf_is_name(type) && !strcmp(pdf_to_name(type), "XRef"))
		{
			opts->use_list[num] = 0;
			pdf_drop_obj(obj);
			return;
		}
	}

	if (!pdf_is_stream(xref, num, gen))
	{
		fprintf(opts->out, "%d %d obj\n", num, gen);
		pdf_fprint_obj(opts->out, obj, opts->do_expand == 0);
		fprintf(opts->out, "endobj\n\n");
	}
	else if (xref->table[num].stm_ofs < 0 && xref->table[num].stm_buf == NULL)
	{
		fprintf(opts->out, "%d %d obj\n", num, gen);
		pdf_fprint_obj(opts->out, obj, opts->do_expand == 0);
		fprintf(opts->out, "stream\nendstream\nendobj\n\n");
	}
	else
	{
		int dontexpand = 0;
		if (opts->do_expand != 0 && opts->do_expand != fz_expand_all)
		{
			pdf_obj *o;

			if ((o = pdf_dict_gets(obj, "Type"), !strcmp(pdf_to_name(o), "XObject")) &&
				(o = pdf_dict_gets(obj, "Subtype"), !strcmp(pdf_to_name(o), "Image")))
				dontexpand = !(opts->do_expand & fz_expand_images);
			if (o = pdf_dict_gets(obj, "Type"), !strcmp(pdf_to_name(o), "Font"))
				dontexpand = !(opts->do_expand & fz_expand_fonts);
			if (o = pdf_dict_gets(obj, "Type"), !strcmp(pdf_to_name(o), "FontDescriptor"))
				dontexpand = !(opts->do_expand & fz_expand_fonts);
			if ((o = pdf_dict_gets(obj, "Length1")) != NULL)
				dontexpand = !(opts->do_expand & fz_expand_fonts);
			if ((o = pdf_dict_gets(obj, "Length2")) != NULL)
				dontexpand = !(opts->do_expand & fz_expand_fonts);
			if ((o = pdf_dict_gets(obj, "Length3")) != NULL)
				dontexpand = !(opts->do_expand & fz_expand_fonts);
			if (o = pdf_dict_gets(obj, "Subtype"), !strcmp(pdf_to_name(o), "Type1C"))
				dontexpand = !(opts->do_expand & fz_expand_fonts);
			if (o = pdf_dict_gets(obj, "Subtype"), !strcmp(pdf_to_name(o), "CIDFontType0C"))
				dontexpand = !(opts->do_expand & fz_expand_fonts);
			if (o = pdf_dict_gets(obj, "Filter"), filter_implies_image(xref, o))
				dontexpand = !(opts->do_expand & fz_expand_images);
			if (pdf_dict_gets(obj, "Width") != NULL && pdf_dict_gets(obj, "Height") != NULL)
				dontexpand = !(opts->do_expand & fz_expand_images);
		}
		fz_try(ctx)
		{
			if (opts->do_expand && !dontexpand && !pdf_is_jpx_image(ctx, obj))
				expandstream(xref, opts, obj, num, gen);
			else
				copystream(xref, opts, obj, num, gen);
		}
		fz_catch(ctx)
		{
			if (opts->continue_on_error)
			{
				fprintf(opts->out, "%d %d obj\nnull\nendobj\n", num, gen);
				if (opts->errors)
					(*opts->errors)++;
				fz_warn(ctx, "%s", fz_caught(ctx));
			}
			else
			{
				pdf_drop_obj(obj);
				fz_rethrow(ctx);
			}
		}
	}

	pdf_drop_obj(obj);
}

static void writexref(pdf_document *xref, pdf_write_options *opts, int from, int to, int first, int main_xref_offset, int startxref)
{
	pdf_obj *trailer = NULL;
	pdf_obj *obj;
	pdf_obj *nobj = NULL;
	int num;
	fz_context *ctx = xref->ctx;

	fprintf(opts->out, "xref\n%d %d\n", from, to - from);
	opts->first_xref_entry_offset = ftell(opts->out);
	for (num = from; num < to; num++)
	{
		if (opts->use_list[num])
			fprintf(opts->out, "%010d %05d n \n", opts->ofs_list[num], opts->gen_list[num]);
		else
			fprintf(opts->out, "%010d %05d f \n", opts->ofs_list[num], opts->gen_list[num]);
	}
	fprintf(opts->out, "\n");

	fz_var(trailer);
	fz_var(nobj);

	fz_try(ctx)
	{
		trailer = pdf_new_dict(ctx, 5);

		nobj = pdf_new_int(ctx, to);
		pdf_dict_puts(trailer, "Size", nobj);
		pdf_drop_obj(nobj);
		nobj = NULL;

		if (first)
		{
			obj = pdf_dict_gets(xref->trailer, "Info");
			if (obj)
				pdf_dict_puts(trailer, "Info", obj);

			obj = pdf_dict_gets(xref->trailer, "Root");
			if (obj)
				pdf_dict_puts(trailer, "Root", obj);

			obj = pdf_dict_gets(xref->trailer, "ID");
			if (obj)
				pdf_dict_puts(trailer, "ID", obj);
		}
		if (main_xref_offset != 0)
		{
			nobj = pdf_new_int(ctx, main_xref_offset);
			pdf_dict_puts(trailer, "Prev", nobj);
			pdf_drop_obj(nobj);
			nobj = NULL;
		}
	}
	fz_always(ctx)
	{
		pdf_drop_obj(nobj);
	}
	fz_catch(ctx)
	{
		fz_rethrow(ctx);
	}

	fprintf(opts->out, "trailer\n");
	pdf_fprint_obj(opts->out, trailer, opts->do_expand == 0);
	fprintf(opts->out, "\n");

	pdf_drop_obj(trailer);

	fprintf(opts->out, "startxref\n%d\n%%%%EOF\n", startxref);
}

static void
padto(FILE *file, int target)
{
	int pos = ftell(file);

	assert(pos <= target);
	while (pos < target)
	{
		fputc('\n', file);
		pos++;
	}
}

static void
dowriteobject(pdf_document *xref, pdf_write_options *opts, int num, int pass)
{
	if (xref->table[num].type == 'f')
		opts->gen_list[num] = xref->table[num].gen;
	if (xref->table[num].type == 'n')
		opts->gen_list[num] = xref->table[num].gen;
	if (xref->table[num].type == 'o')
		opts->gen_list[num] = 0;

	/* If we are renumbering, then make sure all generation numbers are
	 * zero (except object 0 which must be free, and have a gen number of
	 * 65535). Changing the generation numbers (and indeed object numbers)
	 * will break encryption - so only do this if we are renumbering
	 * anyway. */
	if (opts->do_garbage >= 2)
		opts->gen_list[num] = (num == 0 ? 65535 : 0);

	if (opts->do_garbage && !opts->use_list[num])
		return;

	if (xref->table[num].type == 'n' || xref->table[num].type == 'o')
	{
		if (pass > 0)
			padto(opts->out, opts->ofs_list[num]);
		opts->ofs_list[num] = ftell(opts->out);
		writeobject(xref, opts, num, opts->gen_list[num]);
	}
	else
		opts->use_list[num] = 0;
}

static void
writeobjects(pdf_document *xref, pdf_write_options *opts, int pass)
{
	int num;

	fprintf(opts->out, "%%PDF-%d.%d\n", xref->version / 10, xref->version % 10);
	fprintf(opts->out, "%%\316\274\341\277\246\n\n");

	dowriteobject(xref, opts, opts->start, pass);

	if (opts->do_linear)
	{
		/* Write first xref */
		if (pass == 0)
			opts->first_xref_offset = ftell(opts->out);
		else
			padto(opts->out, opts->first_xref_offset);
		writexref(xref, opts, opts->start, xref->len, 1, opts->main_xref_offset, 0);
	}

	for (num = opts->start+1; num < xref->len; num++)
		dowriteobject(xref, opts, num, pass);
	if (opts->do_linear && pass == 1)
	{
		int offset = (opts->start == 1 ? opts->main_xref_offset : opts->ofs_list[1] + opts->hintstream_len);
		padto(opts->out, offset);
	}
	for (num = 1; num < opts->start; num++)
	{
		if (pass == 1)
			opts->ofs_list[num] += opts->hintstream_len;
		dowriteobject(xref, opts, num, pass);
	}
}

static int
my_log2(int x)
{
	int i = 0;

	if (x <= 0)
		return 0;

	while ((1<<i) <= x && (1<<i) > 0)
		i++;

	if ((1<<i) <= 0)
		return 0;

	return i;
}

static void
make_page_offset_hints(pdf_document *xref, pdf_write_options *opts, fz_buffer *buf)
{
	fz_context *ctx = xref->ctx;
	int i, j;
	int min_objs_per_page, max_objs_per_page;
	int min_page_length, max_page_length;
	int objs_per_page_bits;
	int min_shared_object, max_shared_object;
	int max_shared_object_refs;
	int min_shared_length, max_shared_length;
	page_objects **pop = &opts->page_object_lists->page[0];
	int page_len_bits, shared_object_bits, shared_object_id_bits;
	int shared_length_bits;

	min_shared_object = xref->len;
	max_shared_object = 1;
	min_shared_length = opts->file_len;
	max_shared_length = 0;
	for (i=1; i < xref->len; i++)
	{
		int min, max, page;

		min = opts->ofs_list[i];
		if (i == opts->start-1 || (opts->start == 1 && i == xref->len-1))
			max = opts->main_xref_offset;
		else if (i == xref->len-1)
			max = opts->ofs_list[1];
		else
			max = opts->ofs_list[i+1];

		assert(max > min);

		if (opts->use_list[i] & USE_SHARED)
		{
			page = -1;
			if (i < min_shared_object)
				min_shared_object = i;
			if (i > max_shared_object)
				max_shared_object = i;
			if (min_shared_length > max - min)
				min_shared_length = max - min;
			if (max_shared_length < max - min)
				max_shared_length = max - min;
		}
		else if (opts->use_list[i] & (USE_CATALOGUE | USE_HINTS | USE_PARAMS))
			page = -1;
		else if (opts->use_list[i] & USE_PAGE1)
		{
			page = 0;
			if (min_shared_length > max - min)
				min_shared_length = max - min;
			if (max_shared_length < max - min)
				max_shared_length = max - min;
		}
		else if (opts->use_list[i] == 0)
			page = -1;
		else
			page = opts->use_list[i]>>USE_PAGE_SHIFT;

		if (page >= 0)
		{
			pop[page]->num_objects++;
			if (pop[page]->min_ofs > min)
				pop[page]->min_ofs = min;
			if (pop[page]->max_ofs < max)
				pop[page]->max_ofs = max;
		}
	}

	min_objs_per_page = max_objs_per_page = pop[0]->num_objects;
	min_page_length = max_page_length = pop[0]->max_ofs - pop[0]->min_ofs;
	for (i=1; i < opts->page_count; i++)
	{
		int tmp;
		if (min_objs_per_page > pop[i]->num_objects)
			min_objs_per_page = pop[i]->num_objects;
		if (max_objs_per_page < pop[i]->num_objects)
			max_objs_per_page = pop[i]->num_objects;
		tmp = pop[i]->max_ofs - pop[i]->min_ofs;
		if (tmp < min_page_length)
			min_page_length = tmp;
		if (tmp > max_page_length)
			max_page_length = tmp;
	}

	for (i=0; i < opts->page_count; i++)
	{
		int count = 0;
		int j;
		page_objects *po = opts->page_object_lists->page[i];
		for (j = 0; j < po->len; j++)
		{
			if (i == 0 && opts->use_list[po->object[j]] & USE_PAGE1)
				count++;
			else if (i != 0 && opts->use_list[po->object[j]] & USE_SHARED)
				count++;
		}
		po->num_shared = count;
		if (i == 0 || count > max_shared_object_refs)
			max_shared_object_refs = count;
	}
	if (min_shared_object > max_shared_object)
		min_shared_object = max_shared_object = 0;

	/* Table F.3 - Header */
	/* Header Item 1: Least number of objects in a page */
	fz_write_buffer_bits(ctx, buf, min_objs_per_page, 32);
	/* Header Item 2: Location of first pages page object */
	fz_write_buffer_bits(ctx, buf, opts->ofs_list[pop[0]->page_object_number], 32);
	/* Header Item 3: Number of bits required to represent the difference
	 * between the greatest and least number of objects in a page. */
	objs_per_page_bits = my_log2(max_objs_per_page - min_objs_per_page);
	fz_write_buffer_bits(ctx, buf, objs_per_page_bits, 16);
	/* Header Item 4: Least length of a page. */
	fz_write_buffer_bits(ctx, buf, min_page_length, 32);
	/* Header Item 5: Number of bits needed to represent the difference
	 * between the greatest and least length of a page. */
	page_len_bits = my_log2(max_page_length - min_page_length);
	fz_write_buffer_bits(ctx, buf, page_len_bits, 16);
	/* Header Item 6: Least offset to start of content stream (Acrobat
	 * sets this to always be 0) */
	fz_write_buffer_bits(ctx, buf, 0, 32);
	/* Header Item 7: Number of bits needed to represent the difference
	 * between the greatest and least offset to content stream (Acrobat
	 * sets this to always be 0) */
	fz_write_buffer_bits(ctx, buf, 0, 16);
	/* Header Item 8: Least content stream length. (Acrobat
	 * sets this to always be 0) */
	fz_write_buffer_bits(ctx, buf, 0, 32);
	/* Header Item 9: Number of bits needed to represent the difference
	 * between the greatest and least content stream length (Acrobat
	 * sets this to always be the same as item 5) */
	fz_write_buffer_bits(ctx, buf, page_len_bits, 16);
	/* Header Item 10: Number of bits needed to represent the greatest
	 * number of shared object references. */
	shared_object_bits = my_log2(max_shared_object_refs);
	fz_write_buffer_bits(ctx, buf, shared_object_bits, 16);
	/* Header Item 11: Number of bits needed to represent the greatest
	 * shared object identifier. */
	shared_object_id_bits = my_log2(max_shared_object - min_shared_object + pop[0]->num_shared);
	fz_write_buffer_bits(ctx, buf, shared_object_id_bits, 16);
	/* Header Item 12: Number of bits needed to represent the numerator
	 * of the fractions. We always send 0. */
	fz_write_buffer_bits(ctx, buf, 0, 16);
	/* Header Item 13: Number of bits needed to represent the denominator
	 * of the fractions. We always send 0. */
	fz_write_buffer_bits(ctx, buf, 0, 16);

	/* Table F.4 - Page offset hint table (per page) */
	/* Item 1: A number that, when added to the least number of objects
	 * on a page, gives the number of objects in the page. */
	for (i = 0; i < opts->page_count; i++)
	{
		fz_write_buffer_bits(ctx, buf, pop[i]->num_objects - min_objs_per_page, objs_per_page_bits);
	}
	fz_write_buffer_pad(ctx, buf);
	/* Item 2: A number that, when added to the least page length, gives
	 * the length of the page in bytes. */
	for (i = 0; i < opts->page_count; i++)
	{
		fz_write_buffer_bits(ctx, buf, pop[i]->max_ofs - pop[i]->min_ofs - min_page_length, page_len_bits);
	}
	fz_write_buffer_pad(ctx, buf);
	/* Item 3: The number of shared objects referenced from the page. */
	for (i = 0; i < opts->page_count; i++)
	{
		fz_write_buffer_bits(ctx, buf, pop[i]->num_shared, shared_object_bits);
	}
	fz_write_buffer_pad(ctx, buf);
	/* Item 4: Shared object id for each shared object ref in every page.
	 * Spec says "not for page 1", but acrobat does send page 1's - all
	 * as zeros. */
	for (i = 0; i < opts->page_count; i++)
	{
		for (j = 0; j < pop[i]->len; j++)
		{
			int o = pop[i]->object[j];
			if (i == 0 && opts->use_list[o] & USE_PAGE1)
				fz_write_buffer_bits(ctx, buf, 0 /* o - pop[0]->page_object_number */, shared_object_id_bits);
			if (i != 0 && opts->use_list[o] & USE_SHARED)
				fz_write_buffer_bits(ctx, buf, o - min_shared_object + pop[0]->num_shared, shared_object_id_bits);
		}
	}
	fz_write_buffer_pad(ctx, buf);
	/* Item 5: Numerator of fractional position for each shared object reference. */
	/* We always send 0 in 0 bits */
	/* Item 6: A number that, when added to the least offset to the start
	 * of the content stream (F.3 Item 6), gives the offset in bytes of
	 * start of the pages content stream object relative to the beginning
	 * of the page. Always 0 in 0 bits. */
	/* Item 7: A number that, when added to the least content stream length
	 * (F.3 Item 8), gives the length of the pages content stream object.
	 * Always == Item 2 as least content stream length = least page stream
	 * length.
	 */
	for (i = 0; i < opts->page_count; i++)
	{
		fz_write_buffer_bits(ctx, buf, pop[i]->max_ofs - pop[i]->min_ofs - min_page_length, page_len_bits);
	}

	/* Pad, and then do shared object hint table */
	fz_write_buffer_pad(ctx, buf);
	opts->hints_shared_offset = buf->len;

	/* Table F.5: */
	/* Header Item 1: Object number of the first object in the shared
	 * objects section. */
	fz_write_buffer_bits(ctx, buf, min_shared_object, 32);
	/* Header Item 2: Location of first object in the shared objects
	 * section. */
	fz_write_buffer_bits(ctx, buf, opts->ofs_list[min_shared_object], 32);
	/* Header Item 3: The number of shared object entries for the first
	 * page. */
	fz_write_buffer_bits(ctx, buf, pop[0]->num_shared, 32);
	/* Header Item 4: The number of shared object entries for the shared
	 * objects section + first page. */
	fz_write_buffer_bits(ctx, buf, max_shared_object - min_shared_object + pop[0]->num_shared, 32);
	/* Header Item 5: The number of bits needed to represent the greatest
	 * number of objects in a shared object group (Always 0). */
	fz_write_buffer_bits(ctx, buf, 0, 16);
	/* Header Item 6: The least length of a shared object group in bytes. */
	fz_write_buffer_bits(ctx, buf, min_shared_length, 32);
	/* Header Item 7: The number of bits required to represent the
	 * difference between the greatest and least length of a shared object
	 * group. */
	shared_length_bits = my_log2(max_shared_length - min_shared_length);
	fz_write_buffer_bits(ctx, buf, shared_length_bits, 16);

	/* Table F.6 */
	/* Item 1: Shared object group length (page 1 objects) */
	for (j = 0; j < pop[0]->len; j++)
	{
		int o = pop[0]->object[j];
		int min, max;
		min = opts->ofs_list[o];
		if (o == opts->start-1)
			max = opts->main_xref_offset;
		else if (o < xref->len-1)
			max = opts->ofs_list[o+1];
		else
			max = opts->ofs_list[1];
		if (opts->use_list[o] & USE_PAGE1)
			fz_write_buffer_bits(ctx, buf, max - min - min_shared_length, shared_length_bits);
	}
	/* Item 1: Shared object group length (shared objects) */
	for (i = min_shared_object; i <= max_shared_object; i++)
	{
		int min, max;
		min = opts->ofs_list[i];
		if (i == opts->start-1)
			max = opts->main_xref_offset;
		else if (i < xref->len-1)
			max = opts->ofs_list[i+1];
		else
			max = opts->ofs_list[1];
		fz_write_buffer_bits(ctx, buf, max - min - min_shared_length, shared_length_bits);
	}
	fz_write_buffer_pad(ctx, buf);

	/* Item 2: MD5 presence flags */
	for (i = max_shared_object - min_shared_object + pop[0]->num_shared; i > 0; i--)
	{
		fz_write_buffer_bits(ctx, buf, 0, 1);
	}
	fz_write_buffer_pad(ctx, buf);
	/* Item 3: MD5 sums (not present) */
	fz_write_buffer_pad(ctx, buf);
	/* Item 4: Number of objects in the group (not present) */
}

static void
make_hint_stream(pdf_document *xref, pdf_write_options *opts)
{
	fz_context *ctx = xref->ctx;
	fz_buffer *buf = fz_new_buffer(ctx, 100);

	fz_try(ctx)
	{
		make_page_offset_hints(xref, opts, buf);
		pdf_update_stream(xref, xref->len-1, buf);
		opts->hintstream_len = buf->len;
		fz_drop_buffer(ctx, buf);
	}
	fz_catch(ctx)
	{
		fz_drop_buffer(ctx, buf);
		fz_rethrow(ctx);
	}
}

#ifdef DEBUG_WRITING
static void dump_object_details(pdf_document *xref, pdf_write_options *opts)
{
	int i;

	for (i = 0; i < xref->len; i++)
	{
		fprintf(stderr, "%d@%d: use=%d\n", i, opts->ofs_list[i], opts->use_list[i]);
	}
}
#endif


void pdf_write_document(pdf_document *xref, char *filename, fz_write_options *fz_opts)
{
	int lastfree;
	int num;
	pdf_write_options opts = { 0 };
	fz_context *ctx;

	if (!xref)
		return;

	ctx = xref->ctx;

	opts.out = fopen(filename, "wb");
	if (!opts.out)
		fz_throw(ctx, "cannot open output file '%s'", filename);

	fz_try(ctx)
	{
		opts.do_expand = fz_opts ? fz_opts->do_expand : 0;
		opts.do_garbage = fz_opts ? fz_opts->do_garbage : 0;
		opts.do_ascii = fz_opts ? fz_opts->do_ascii: 0;
		opts.do_linear = fz_opts ? fz_opts->do_linear: 0;
		opts.start = 0;
		opts.main_xref_offset = INT_MIN;
		/* We deliberately make these arrays long enough to cope with
		 * 1 to n access rather than 0..n-1, and add space for 2 new
		 * extra entries that may be required for linearization. */
		opts.use_list = fz_malloc_array(ctx, xref->len + 3, sizeof(int));
		opts.ofs_list = fz_malloc_array(ctx, xref->len + 3, sizeof(int));
		opts.gen_list = fz_calloc(ctx, xref->len + 3, sizeof(int));
		opts.renumber_map = fz_malloc_array(ctx, xref->len + 3, sizeof(int));
		opts.rev_renumber_map = fz_malloc_array(ctx, xref->len + 3, sizeof(int));
		opts.rev_gen_list = fz_malloc_array(ctx, xref->len + 3, sizeof(int));
		opts.continue_on_error = fz_opts->continue_on_error;
		opts.errors = fz_opts->errors;

		for (num = 0; num < xref->len; num++)
		{
			opts.use_list[num] = 0;
			opts.ofs_list[num] = 0;
			opts.renumber_map[num] = num;
			opts.rev_renumber_map[num] = num;
			opts.rev_gen_list[num] = xref->table[num].gen;
		}

		/* Make sure any objects hidden in compressed streams have been loaded */
		preloadobjstms(xref);

		/* Sweep & mark objects from the trailer */
		if (opts.do_garbage >= 1)
			sweepobj(xref, &opts, xref->trailer);
		else
			for (num = 0; num < xref->len; num++)
				opts.use_list[num] = 1;

		/* Coalesce and renumber duplicate objects */
		if (opts.do_garbage >= 3)
			removeduplicateobjs(xref, &opts);

		/* Compact xref by renumbering and removing unused objects */
		if (opts.do_garbage >= 2 || opts.do_linear)
			compactxref(xref, &opts);

		/* Make renumbering affect all indirect references and update xref */
		if (opts.do_garbage >= 2 || opts.do_linear)
			renumberobjs(xref, &opts);

		if (opts.do_linear)
		{
			linearize(xref, &opts);
		}

		writeobjects(xref, &opts, 0);

#ifdef DEBUG_WRITING
		dump_object_details(xref, &opts);
#endif

		/* Construct linked list of free object slots */
		lastfree = 0;
		for (num = 0; num < xref->len; num++)
		{
			if (!opts.use_list[num])
			{
				opts.gen_list[num]++;
				opts.ofs_list[lastfree] = num;
				lastfree = num;
			}
		}

		if (opts.do_linear)
		{
			opts.main_xref_offset = ftell(opts.out);
			writexref(xref, &opts, 0, opts.start, 0, 0, opts.first_xref_offset);
			opts.file_len = ftell(opts.out);

			make_hint_stream(xref, &opts);
			opts.file_len += opts.hintstream_len;
			opts.main_xref_offset += opts.hintstream_len;
			update_linearization_params(xref, &opts);
			fseek(opts.out, 0, 0);
			writeobjects(xref, &opts, 1);

			padto(opts.out, opts.main_xref_offset);
			writexref(xref, &opts, 0, opts.start, 0, 0, opts.first_xref_offset);
		}
		else
		{
			opts.first_xref_offset = ftell(opts.out);
			writexref(xref, &opts, 0, xref->len, 1, 0, opts.first_xref_offset);
		}

		xref->dirty = 0;
	}
	fz_always(ctx)
	{
#ifdef DEBUG_LINEARIZATION
		page_objects_dump(&opts);
		objects_dump(xref, &opts);
#endif
		fz_free(ctx, opts.use_list);
		fz_free(ctx, opts.ofs_list);
		fz_free(ctx, opts.gen_list);
		fz_free(ctx, opts.renumber_map);
		fz_free(ctx, opts.rev_renumber_map);
		fz_free(ctx, opts.rev_gen_list);
		pdf_drop_obj(opts.linear_l);
		pdf_drop_obj(opts.linear_h0);
		pdf_drop_obj(opts.linear_h1);
		pdf_drop_obj(opts.linear_o);
		pdf_drop_obj(opts.linear_e);
		pdf_drop_obj(opts.linear_n);
		pdf_drop_obj(opts.linear_t);
		pdf_drop_obj(opts.hints_s);
		pdf_drop_obj(opts.hints_length);
		page_objects_list_destroy(ctx, opts.page_object_lists);
		fclose(opts.out);
	}
	fz_catch(ctx)
	{
		fz_rethrow(ctx);
	}
}