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Regard whitespace Rev 4679 → Rev 4680

/contrib/media/updf/apps/pdfclean.c
0,0 → 1,775
/*
* PDF cleaning tool: general purpose pdf syntax washer.
*
* Rewrite PDF with pretty printed objects.
* Garbage collect unreachable objects.
* Inflate compressed streams.
* Create subset documents.
*
* TODO: linearize document for fast web view
*/
 
#include "fitz.h"
#include "mupdf.h"
 
static FILE *out = NULL;
 
static char *uselist = NULL;
static int *ofslist = NULL;
static int *genlist = NULL;
static int *renumbermap = NULL;
 
static int dogarbage = 0;
static int doexpand = 0;
static int doascii = 0;
 
static pdf_xref *xref = NULL;
 
void die(fz_error error)
{
fz_catch(error, "aborting");
if (xref)
pdf_free_xref(xref);
exit(1);
}
 
static void usage(void)
{
fprintf(stderr,
"usage: pdfclean [options] input.pdf [output.pdf] [pages]\n"
"\t-p -\tpassword\n"
"\t-g\tgarbage collect unused objects\n"
"\t-gg\tin addition to -g compact xref table\n"
"\t-ggg\tin addition to -gg merge duplicate objects\n"
"\t-d\tdecompress streams\n"
"\t-a\tascii hex encode binary streams\n"
"\tpages\tcomma separated list of ranges\n");
exit(1);
}
 
/*
* Garbage collect objects not reachable from the trailer.
*/
 
static void sweepref(fz_obj *ref);
 
static void sweepobj(fz_obj *obj)
{
int i;
 
if (fz_is_indirect(obj))
sweepref(obj);
 
else if (fz_is_dict(obj))
for (i = 0; i < fz_dict_len(obj); i++)
sweepobj(fz_dict_get_val(obj, i));
 
else if (fz_is_array(obj))
for (i = 0; i < fz_array_len(obj); i++)
sweepobj(fz_array_get(obj, i));
}
 
static void sweepref(fz_obj *obj)
{
int num = fz_to_num(obj);
int gen = fz_to_gen(obj);
 
if (num < 0 || num >= xref->len)
return;
if (uselist[num])
return;
 
uselist[num] = 1;
 
/* Bake in /Length in stream objects */
if (pdf_is_stream(xref, num, gen))
{
fz_obj *len = fz_dict_gets(obj, "Length");
if (fz_is_indirect(len))
{
uselist[fz_to_num(len)] = 0;
len = fz_resolve_indirect(len);
fz_dict_puts(obj, "Length", len);
}
}
 
sweepobj(fz_resolve_indirect(obj));
}
 
/*
* Scan for and remove duplicate objects (slow)
*/
 
static void removeduplicateobjs(void)
{
int num, other;
 
for (num = 1; num < xref->len; num++)
{
/* Only compare an object to objects preceeding it */
for (other = 1; other < num; other++)
{
fz_obj *a, *b;
 
if (num == other || !uselist[num] || !uselist[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.
*/
if (pdf_is_stream(xref, num, 0) || pdf_is_stream(xref, other, 0))
continue;
 
a = xref->table[num].obj;
b = xref->table[other].obj;
 
a = fz_resolve_indirect(a);
b = fz_resolve_indirect(b);
 
if (fz_objcmp(a, b))
continue;
 
/* Keep the lowest numbered object */
renumbermap[num] = MIN(num, other);
renumbermap[other] = MIN(num, other);
uselist[MAX(num, other)] = 0;
 
/* One duplicate was found, do not look for another */
break;
}
}
}
 
/*
* Renumber objects sequentially so the xref is more compact
*/
 
static void compactxref(void)
{
int num, newnum;
 
/*
* Update renumbermap 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 (uselist[num] && renumbermap[num] == num)
renumbermap[num] = newnum++;
else if (renumbermap[num] != num)
renumbermap[num] = renumbermap[renumbermap[num]];
}
}
 
/*
* Update indirect objects according to renumbering established when
* removing duplicate objects and compacting the xref.
*/
 
static void renumberobj(fz_obj *obj)
{
int i;
 
if (fz_is_dict(obj))
{
for (i = 0; i < fz_dict_len(obj); i++)
{
fz_obj *key = fz_dict_get_key(obj, i);
fz_obj *val = fz_dict_get_val(obj, i);
if (fz_is_indirect(val))
{
val = fz_new_indirect(renumbermap[fz_to_num(val)], 0, xref);
fz_dict_put(obj, key, val);
fz_drop_obj(val);
}
else
{
renumberobj(val);
}
}
}
 
else if (fz_is_array(obj))
{
for (i = 0; i < fz_array_len(obj); i++)
{
fz_obj *val = fz_array_get(obj, i);
if (fz_is_indirect(val))
{
val = fz_new_indirect(renumbermap[fz_to_num(val)], 0, xref);
fz_array_put(obj, i, val);
fz_drop_obj(val);
}
else
{
renumberobj(val);
}
}
}
}
 
static void renumberobjs(void)
{
pdf_xref_entry *oldxref;
int newlen;
int num;
 
/* Apply renumber map to indirect references in all objects in xref */
renumberobj(xref->trailer);
for (num = 0; num < xref->len; num++)
{
fz_obj *obj = xref->table[num].obj;
 
if (fz_is_indirect(obj))
{
obj = fz_new_indirect(renumbermap[fz_to_num(obj)], 0, xref);
pdf_update_object(xref, num, 0, obj);
fz_drop_obj(obj);
}
else
{
renumberobj(obj);
}
}
 
/* Create new table for the reordered, compacted xref */
oldxref = xref->table;
xref->table = fz_calloc(xref->len, 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 (uselist[num])
{
if (newlen < renumbermap[num])
newlen = renumbermap[num];
xref->table[renumbermap[num]] = oldxref[num];
}
else
{
if (oldxref[num].obj)
fz_drop_obj(oldxref[num].obj);
}
}
 
fz_free(oldxref);
 
/* Update the used objects count in compacted xref */
xref->len = newlen + 1;
 
/* Update list of used objects to fit with compacted xref */
for (num = 1; num < xref->len; num++)
uselist[num] = 1;
}
 
/*
* Recreate page tree to only retain specified pages.
*/
 
static void retainpages(int argc, char **argv)
{
fz_error error;
fz_obj *oldroot, *root, *pages, *kids, *countobj, *parent;
 
/* Load the old page tree */
error = pdf_load_page_tree(xref);
if (error)
die(fz_rethrow(error, "cannot load page tree"));
 
/* Keep only pages/type entry to avoid references to unretained pages */
oldroot = fz_dict_gets(xref->trailer, "Root");
pages = fz_dict_gets(oldroot, "Pages");
 
root = fz_new_dict(2);
fz_dict_puts(root, "Type", fz_dict_gets(oldroot, "Type"));
fz_dict_puts(root, "Pages", fz_dict_gets(oldroot, "Pages"));
 
pdf_update_object(xref, fz_to_num(oldroot), fz_to_gen(oldroot), root);
 
fz_drop_obj(root);
 
/* Create a new kids array with only the pages we want to keep */
parent = fz_new_indirect(fz_to_num(pages), fz_to_gen(pages), xref);
kids = fz_new_array(1);
 
/* Retain pages specified */
while (argc - fz_optind)
{
int page, spage, epage;
char *spec, *dash;
char *pagelist = argv[fz_optind];
 
spec = fz_strsep(&pagelist, ",");
while (spec)
{
dash = strchr(spec, '-');
 
if (dash == spec)
spage = epage = pdf_count_pages(xref);
else
spage = epage = atoi(spec);
 
if (dash)
{
if (strlen(dash) > 1)
epage = atoi(dash + 1);
else
epage = pdf_count_pages(xref);
}
 
if (spage > epage)
page = spage, spage = epage, epage = page;
 
if (spage < 1)
spage = 1;
if (epage > pdf_count_pages(xref))
epage = pdf_count_pages(xref);
 
for (page = spage; page <= epage; page++)
{
fz_obj *pageobj = xref->page_objs[page-1];
fz_obj *pageref = xref->page_refs[page-1];
 
fz_dict_puts(pageobj, "Parent", parent);
 
/* Store page object in new kids array */
fz_array_push(kids, pageref);
}
 
spec = fz_strsep(&pagelist, ",");
}
 
fz_optind++;
}
 
fz_drop_obj(parent);
 
/* Update page count and kids array */
countobj = fz_new_int(fz_array_len(kids));
fz_dict_puts(pages, "Count", countobj);
fz_drop_obj(countobj);
fz_dict_puts(pages, "Kids", kids);
fz_drop_obj(kids);
}
 
/*
* Make sure we have loaded objects from object streams.
*/
 
static void preloadobjstms(void)
{
fz_error error;
fz_obj *obj;
int num;
 
for (num = 0; num < xref->len; num++)
{
if (xref->table[num].type == 'o')
{
error = pdf_load_object(&obj, xref, num, 0);
if (error)
die(error);
fz_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(unsigned char *p, int n)
{
static const char hex[16] = "0123456789abcdef";
fz_buffer *buf;
int x = 0;
 
buf = fz_new_buffer(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(fz_obj *dict)
{
fz_obj *f, *dp, *newf, *newdp;
fz_obj *ahx, *nullobj;
 
ahx = fz_new_name("ASCIIHexDecode");
nullobj = fz_new_null();
newf = newdp = NULL;
 
f = fz_dict_gets(dict, "Filter");
dp = fz_dict_gets(dict, "DecodeParms");
 
if (fz_is_name(f))
{
newf = fz_new_array(2);
fz_array_push(newf, ahx);
fz_array_push(newf, f);
f = newf;
if (fz_is_dict(dp))
{
newdp = fz_new_array(2);
fz_array_push(newdp, nullobj);
fz_array_push(newdp, dp);
dp = newdp;
}
}
else if (fz_is_array(f))
{
fz_array_insert(f, ahx);
if (fz_is_array(dp))
fz_array_insert(dp, nullobj);
}
else
f = ahx;
 
fz_dict_puts(dict, "Filter", f);
if (dp)
fz_dict_puts(dict, "DecodeParms", dp);
 
fz_drop_obj(ahx);
fz_drop_obj(nullobj);
if (newf)
fz_drop_obj(newf);
if (newdp)
fz_drop_obj(newdp);
}
 
static void copystream(fz_obj *obj, int num, int gen)
{
fz_error error;
fz_buffer *buf, *tmp;
fz_obj *newlen;
 
error = pdf_load_raw_stream(&buf, xref, num, gen);
if (error)
die(error);
 
if (doascii && isbinarystream(buf))
{
tmp = hexbuf(buf->data, buf->len);
fz_drop_buffer(buf);
buf = tmp;
 
addhexfilter(obj);
 
newlen = fz_new_int(buf->len);
fz_dict_puts(obj, "Length", newlen);
fz_drop_obj(newlen);
}
 
fprintf(out, "%d %d obj\n", num, gen);
fz_fprint_obj(out, obj, !doexpand);
fprintf(out, "stream\n");
fwrite(buf->data, 1, buf->len, out);
fprintf(out, "endstream\nendobj\n\n");
 
fz_drop_buffer(buf);
}
 
static void expandstream(fz_obj *obj, int num, int gen)
{
fz_error error;
fz_buffer *buf, *tmp;
fz_obj *newlen;
 
error = pdf_load_stream(&buf, xref, num, gen);
if (error)
die(error);
 
fz_dict_dels(obj, "Filter");
fz_dict_dels(obj, "DecodeParms");
 
if (doascii && isbinarystream(buf))
{
tmp = hexbuf(buf->data, buf->len);
fz_drop_buffer(buf);
buf = tmp;
 
addhexfilter(obj);
}
 
newlen = fz_new_int(buf->len);
fz_dict_puts(obj, "Length", newlen);
fz_drop_obj(newlen);
 
fprintf(out, "%d %d obj\n", num, gen);
fz_fprint_obj(out, obj, !doexpand);
fprintf(out, "stream\n");
fwrite(buf->data, 1, buf->len, out);
fprintf(out, "endstream\nendobj\n\n");
 
fz_drop_buffer(buf);
}
 
static void writeobject(int num, int gen)
{
fz_error error;
fz_obj *obj;
fz_obj *type;
 
error = pdf_load_object(&obj, xref, num, gen);
if (error)
die(error);
 
/* skip ObjStm and XRef objects */
if (fz_is_dict(obj))
{
type = fz_dict_gets(obj, "Type");
if (fz_is_name(type) && !strcmp(fz_to_name(type), "ObjStm"))
{
uselist[num] = 0;
fz_drop_obj(obj);
return;
}
if (fz_is_name(type) && !strcmp(fz_to_name(type), "XRef"))
{
uselist[num] = 0;
fz_drop_obj(obj);
return;
}
}
 
if (!pdf_is_stream(xref, num, gen))
{
fprintf(out, "%d %d obj\n", num, gen);
fz_fprint_obj(out, obj, !doexpand);
fprintf(out, "endobj\n\n");
}
else
{
if (doexpand && !pdf_is_jpx_image(obj))
expandstream(obj, num, gen);
else
copystream(obj, num, gen);
}
 
fz_drop_obj(obj);
}
 
static void writexref(void)
{
fz_obj *trailer;
fz_obj *obj;
int startxref;
int num;
 
startxref = ftell(out);
 
fprintf(out, "xref\n0 %d\n", xref->len);
for (num = 0; num < xref->len; num++)
{
if (uselist[num])
fprintf(out, "%010d %05d n \n", ofslist[num], genlist[num]);
else
fprintf(out, "%010d %05d f \n", ofslist[num], genlist[num]);
}
fprintf(out, "\n");
 
trailer = fz_new_dict(5);
 
obj = fz_new_int(xref->len);
fz_dict_puts(trailer, "Size", obj);
fz_drop_obj(obj);
 
obj = fz_dict_gets(xref->trailer, "Info");
if (obj)
fz_dict_puts(trailer, "Info", obj);
 
obj = fz_dict_gets(xref->trailer, "Root");
if (obj)
fz_dict_puts(trailer, "Root", obj);
 
obj = fz_dict_gets(xref->trailer, "ID");
if (obj)
fz_dict_puts(trailer, "ID", obj);
 
fprintf(out, "trailer\n");
fz_fprint_obj(out, trailer, !doexpand);
fprintf(out, "\n");
 
fz_drop_obj(trailer);
 
fprintf(out, "startxref\n%d\n%%%%EOF\n", startxref);
}
 
static void writepdf(void)
{
int lastfree;
int num;
 
for (num = 0; num < xref->len; num++)
{
if (xref->table[num].type == 'f')
genlist[num] = xref->table[num].gen;
if (xref->table[num].type == 'n')
genlist[num] = xref->table[num].gen;
if (xref->table[num].type == 'o')
genlist[num] = 0;
 
if (dogarbage && !uselist[num])
continue;
 
if (xref->table[num].type == 'n' || xref->table[num].type == 'o')
{
uselist[num] = 1;
ofslist[num] = ftell(out);
writeobject(num, genlist[num]);
}
}
 
/* Construct linked list of free object slots */
lastfree = 0;
for (num = 0; num < xref->len; num++)
{
if (!uselist[num])
{
genlist[num]++;
ofslist[lastfree] = num;
lastfree = num;
}
}
 
writexref();
}
 
int main(int argc, char **argv)
{
fz_error error;
char *infile;
char *outfile = "out.pdf";
char *password = "";
int c, num;
int subset;
 
while ((c = fz_getopt(argc, argv, "adgp:")) != -1)
{
switch (c)
{
case 'p': password = fz_optarg; break;
case 'g': dogarbage ++; break;
case 'd': doexpand ++; break;
case 'a': doascii ++; break;
default: usage(); break;
}
}
 
if (argc - fz_optind < 1)
usage();
 
infile = argv[fz_optind++];
 
if (argc - fz_optind > 0 &&
(strstr(argv[fz_optind], ".pdf") || strstr(argv[fz_optind], ".PDF")))
{
outfile = argv[fz_optind++];
}
 
subset = 0;
if (argc - fz_optind > 0)
subset = 1;
 
error = pdf_open_xref(&xref, infile, password);
if (error)
die(fz_rethrow(error, "cannot open input file '%s'", infile));
 
out = fopen(outfile, "wb");
if (!out)
die(fz_throw("cannot open output file '%s'", outfile));
 
fprintf(out, "%%PDF-%d.%d\n", xref->version / 10, xref->version % 10);
fprintf(out, "%%\316\274\341\277\246\n\n");
 
uselist = fz_calloc(xref->len + 1, sizeof(char));
ofslist = fz_calloc(xref->len + 1, sizeof(int));
genlist = fz_calloc(xref->len + 1, sizeof(int));
renumbermap = fz_calloc(xref->len + 1, sizeof(int));
 
for (num = 0; num < xref->len; num++)
{
uselist[num] = 0;
ofslist[num] = 0;
genlist[num] = 0;
renumbermap[num] = num;
}
 
/* Make sure any objects hidden in compressed streams have been loaded */
preloadobjstms();
 
/* Only retain the specified subset of the pages */
if (subset)
retainpages(argc, argv);
 
/* Sweep & mark objects from the trailer */
if (dogarbage >= 1)
sweepobj(xref->trailer);
 
/* Coalesce and renumber duplicate objects */
if (dogarbage >= 3)
removeduplicateobjs();
 
/* Compact xref by renumbering and removing unused objects */
if (dogarbage >= 2)
compactxref();
 
/* Make renumbering affect all indirect references and update xref */
if (dogarbage >= 2)
renumberobjs();
 
writepdf();
 
if (fclose(out))
die(fz_throw("cannot close output file '%s'", outfile));
 
fz_free(uselist);
fz_free(ofslist);
fz_free(genlist);
fz_free(renumbermap);
 
pdf_free_xref(xref);
 
fz_flush_warnings();
 
return 0;
}