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-rw-r--r--pdf/mupdf-internal.h16
-rw-r--r--pdf/pdf_repair.c19
-rw-r--r--pdf/pdf_xref.c204
3 files changed, 185 insertions, 54 deletions
diff --git a/pdf/mupdf-internal.h b/pdf/mupdf-internal.h
index b7931e4f..a0c8f599 100644
--- a/pdf/mupdf-internal.h
+++ b/pdf/mupdf-internal.h
@@ -119,6 +119,13 @@ struct pdf_hotspot_s
typedef struct pdf_js_s pdf_js;
+typedef struct pdf_xref_s
+{
+ int len;
+ pdf_xref_entry *table;
+ pdf_obj *trailer;
+} pdf_xref;
+
struct pdf_document_s
{
fz_document super;
@@ -130,12 +137,12 @@ struct pdf_document_s
int startxref;
int file_size;
pdf_crypt *crypt;
- pdf_obj *trailer;
pdf_ocg_descriptor *ocg;
pdf_hotspot hotspot;
- int len;
- pdf_xref_entry *table;
+ int num_xref_sections;
+ pdf_xref *xref_sections;
+ int xref_altered;
int page_len;
int page_cap;
@@ -174,8 +181,9 @@ fz_buffer *pdf_load_renumbered_stream(pdf_document *doc, int num, int gen, int o
fz_stream *pdf_open_raw_renumbered_stream(pdf_document *doc, int num, int gen, int orig_num, int orig_gen);
pdf_obj *pdf_trailer(pdf_document *doc);
-void pdf_set_xref_trailer(pdf_document *doc, pdf_obj *trailer);
+void pdf_set_populating_xref_trailer(pdf_document *doc, pdf_obj *trailer);
int pdf_xref_len(pdf_document *doc);
+pdf_xref_entry *pdf_get_populating_xref_entry(pdf_document *doc, int i);
pdf_xref_entry *pdf_get_xref_entry(pdf_document *doc, int i);
void pdf_replace_xref(pdf_document *doc, pdf_xref_entry *entries, int n);
diff --git a/pdf/pdf_repair.c b/pdf/pdf_repair.c
index 1127fe1f..e5a1a8a9 100644
--- a/pdf/pdf_repair.c
+++ b/pdf/pdf_repair.c
@@ -182,7 +182,7 @@ pdf_repair_obj_stm(pdf_document *xref, int num, int gen)
continue;
}
- entry = pdf_get_xref_entry(xref, n);
+ entry = pdf_get_populating_xref_entry(xref, n);
entry->ofs = num;
entry->gen = i;
entry->stm_ofs = 0;
@@ -405,11 +405,11 @@ pdf_repair_xref(pdf_document *xref, pdf_lexbuf *buf)
Dummy access to entry to assure sufficient space in the xref table
and avoid repeated reallocs in the loop
*/
- (void)pdf_get_xref_entry(xref, maxnum);
+ (void)pdf_get_populating_xref_entry(xref, maxnum);
for (i = 0; i < listlen; i++)
{
- entry = pdf_get_xref_entry(xref, list[i].num);
+ entry = pdf_get_populating_xref_entry(xref, list[i].num);
entry->type = 'n';
entry->ofs = list[i].ofs;
entry->gen = list[i].gen;
@@ -429,7 +429,7 @@ pdf_repair_xref(pdf_document *xref, pdf_lexbuf *buf)
}
}
- entry = pdf_get_xref_entry(xref, 0);
+ entry = pdf_get_populating_xref_entry(xref, 0);
entry->type = 'f';
entry->ofs = 0;
entry->gen = 65535;
@@ -439,7 +439,7 @@ pdf_repair_xref(pdf_document *xref, pdf_lexbuf *buf)
next = 0;
for (i = pdf_xref_len(xref) - 1; i >= 0; i--)
{
- entry = pdf_get_xref_entry(xref, i);
+ entry = pdf_get_populating_xref_entry(xref, i);
if (entry->type == 'f')
{
entry->ofs = next;
@@ -452,7 +452,8 @@ pdf_repair_xref(pdf_document *xref, pdf_lexbuf *buf)
/* create a repaired trailer, Root will be added later */
obj = pdf_new_dict(ctx, 5);
- pdf_set_xref_trailer(xref, obj);
+ /* During repair there is only a single xref section */
+ pdf_set_populating_xref_trailer(xref, obj);
pdf_drop_obj(obj);
obj = NULL;
@@ -526,7 +527,7 @@ pdf_repair_obj_stms(pdf_document *xref)
for (i = 0; i < xref_len; i++)
{
- pdf_xref_entry *entry = pdf_get_xref_entry(xref, i);
+ pdf_xref_entry *entry = pdf_get_populating_xref_entry(xref, i);
if (entry->stm_ofs)
{
@@ -550,9 +551,9 @@ pdf_repair_obj_stms(pdf_document *xref)
/* Ensure that streamed objects reside inside a known non-streamed object */
for (i = 0; i < xref_len; i++)
{
- pdf_xref_entry *entry = pdf_get_xref_entry(xref, i);
+ pdf_xref_entry *entry = pdf_get_populating_xref_entry(xref, i);
- if (entry->type == 'o' && pdf_get_xref_entry(xref, entry->ofs)->type != 'n')
+ if (entry->type == 'o' && pdf_get_populating_xref_entry(xref, entry->ofs)->type != 'n')
fz_throw(xref->ctx, "invalid reference to non-object-stream: %d (%d 0 R)", entry->ofs, i);
}
}
diff --git a/pdf/pdf_xref.c b/pdf/pdf_xref.c
index 2675b0ce..14b8ee5b 100644
--- a/pdf/pdf_xref.c
+++ b/pdf/pdf_xref.c
@@ -12,11 +12,40 @@ static inline int iswhite(int ch)
* xref tables
*/
-static void pdf_resize_xref(pdf_document *xref, int newlen)
+static void pdf_free_xref_sections(pdf_document *doc)
+{
+ fz_context *ctx = doc->ctx;
+ int x, e;
+
+ for (x = 0; x < doc->num_xref_sections; x++)
+ {
+ pdf_xref *xref = &doc->xref_sections[x];
+
+ for (e = 0; e < xref->len; e++)
+ {
+ pdf_xref_entry *entry = &xref->table[e];
+
+ if (entry->obj)
+ {
+ pdf_drop_obj(entry->obj);
+ fz_drop_buffer(ctx, entry->stm_buf);
+ }
+ }
+
+ fz_free(ctx, xref->table);
+ pdf_drop_obj(xref->trailer);
+ }
+
+ fz_free(ctx, doc->xref_sections);
+ doc->xref_sections = NULL;
+ doc->num_xref_sections = 0;
+}
+
+static void pdf_resize_xref(fz_context *ctx, pdf_xref *xref, int newlen)
{
int i;
- xref->table = fz_resize_array(xref->ctx, xref->table, newlen, sizeof(pdf_xref_entry));
+ xref->table = fz_resize_array(ctx, xref->table, newlen, sizeof(pdf_xref_entry));
for (i = xref->len; i < newlen; i++)
{
xref->table[i].type = 0;
@@ -29,35 +58,140 @@ static void pdf_resize_xref(pdf_document *xref, int newlen)
xref->len = newlen;
}
+static void pdf_populate_next_xref_level(pdf_document *doc)
+{
+ pdf_xref *xref;
+ doc->xref_sections = fz_resize_array(doc->ctx, doc->xref_sections, doc->num_xref_sections + 1, sizeof(pdf_xref));
+ doc->num_xref_sections++;
+
+ xref = &doc->xref_sections[doc->num_xref_sections - 1];
+ xref->len = 0;
+ xref->table = NULL;
+ xref->trailer = NULL;
+}
+
pdf_obj *pdf_trailer(pdf_document *doc)
{
- return doc->trailer;
+ /* Return the document's final trailer */
+ pdf_xref *xref = &doc->xref_sections[0];
+
+ return xref->trailer;
}
-void pdf_set_xref_trailer(pdf_document *doc, pdf_obj *trailer)
+void pdf_set_populating_xref_trailer(pdf_document *doc, pdf_obj *trailer)
{
- pdf_drop_obj(doc->trailer);
- doc->trailer = pdf_keep_obj(trailer);
+ /* Update the trailer of the xref section being populated */
+ pdf_xref *xref = &doc->xref_sections[doc->num_xref_sections - 1];
+ pdf_drop_obj(xref->trailer);
+ xref->trailer = pdf_keep_obj(trailer);
}
int pdf_xref_len(pdf_document *doc)
{
- return doc->len;
+ /* Return the length of the document's final xref section */
+ pdf_xref *xref = &doc->xref_sections[0];
+
+ return xref->len;
}
+/* Used while reading the individual xref sections from a file */
+pdf_xref_entry *pdf_get_populating_xref_entry(pdf_document *doc, int i)
+{
+ /* Return an entry within the xref currently being populated */
+ pdf_xref *xref;
+
+ if (doc->num_xref_sections == 0)
+ {
+ doc->xref_sections = fz_calloc(doc->ctx, 1, sizeof(pdf_xref));
+ doc->num_xref_sections = 1;
+ }
+
+ xref = &doc->xref_sections[doc->num_xref_sections - 1];
+
+ if (i >= xref->len)
+ pdf_resize_xref(doc->ctx, xref, i+1);
+
+ return &xref->table[i];
+}
+
+/* Used after loading a document to access entries */
pdf_xref_entry *pdf_get_xref_entry(pdf_document *doc, int i)
{
- if (i >= doc->len)
- pdf_resize_xref(doc, i+1);
+ int j;
- return &doc->table[i];
+ /* Find the first xref section where the entry is defined. */
+ for (j = 0; j < doc->num_xref_sections; j++)
+ {
+ pdf_xref *xref = &doc->xref_sections[j];
+
+ if (i >= 0 && i < xref->len)
+ {
+ pdf_xref_entry *entry = &xref->table[i];
+
+ if (entry->type)
+ return entry;
+ }
+ }
+
+ /*
+ Didn't find the entry in any section. Return the entry from the final
+ section.
+ */
+ return &doc->xref_sections[0].table[i];
+}
+
+/* Used when altering a document */
+static pdf_xref_entry *pdf_get_new_xref_entry(pdf_document *doc, int i)
+{
+ fz_context *ctx = doc->ctx;
+ pdf_xref *xref;
+
+ /* Make a new final xref section if we haven't already */
+ if (!doc->xref_altered)
+ {
+ doc->xref_sections = fz_resize_array(ctx, doc->xref_sections, doc->num_xref_sections + 1, sizeof(pdf_xref));
+ memmove(&doc->xref_sections[1], &doc->xref_sections[0], doc->num_xref_sections * sizeof(pdf_xref));
+ doc->num_xref_sections++;
+ xref = &doc->xref_sections[0];
+ xref->len = 0;
+ xref->table = NULL;
+ xref->trailer = pdf_keep_obj(doc->xref_sections[1].trailer);
+ doc->xref_altered = 1;
+ }
+
+ xref = &doc->xref_sections[0];
+ if (i >= xref->len)
+ pdf_resize_xref(ctx, xref, i + 1);
+
+ return &xref->table[i];
}
void pdf_replace_xref(pdf_document *doc, pdf_xref_entry *entries, int n)
{
- fz_free(doc->ctx, doc->table);
- doc->table = entries;
- doc->len = n;
+ fz_context *ctx = doc->ctx;
+ pdf_xref *xref;
+ pdf_obj *trailer = pdf_keep_obj(pdf_trailer(doc));
+
+ /* The new table completely replaces the previous separate sections */
+ pdf_free_xref_sections(doc);
+
+ fz_var(trailer);
+ fz_try(ctx)
+ {
+ xref = fz_calloc(ctx, 1, sizeof(pdf_xref));
+ xref->table = entries;
+ xref->len = n;
+ xref->trailer = trailer;
+ trailer = NULL;
+
+ doc->xref_sections = xref;
+ doc->num_xref_sections = 1;
+ }
+ fz_catch(ctx)
+ {
+ pdf_drop_obj(trailer);
+ fz_rethrow(ctx);
+ }
}
/*
@@ -207,7 +341,7 @@ pdf_read_old_xref(pdf_document *xref, pdf_lexbuf *buf)
int xref_len = pdf_xref_size_from_old_trailer(xref, buf);
/* Access last entry to ensure xref size up front and avoid reallocs */
- (void)pdf_get_xref_entry(xref, xref_len - 1);
+ (void)pdf_get_populating_xref_entry(xref, xref_len - 1);
fz_read_line(xref->file, buf->scratch, buf->size);
if (strncmp(buf->scratch, "xref", 4) != 0)
@@ -239,12 +373,12 @@ pdf_read_old_xref(pdf_document *xref, pdf_lexbuf *buf)
{
fz_warn(xref->ctx, "broken xref section, proceeding anyway.");
/* Access last entry to ensure size */
- (void)pdf_get_xref_entry(xref, ofs + len - 1);
+ (void)pdf_get_populating_xref_entry(xref, ofs + len - 1);
}
for (i = ofs; i < ofs + len; i++)
{
- pdf_xref_entry *entry = pdf_get_xref_entry(xref, i);
+ pdf_xref_entry *entry = pdf_get_populating_xref_entry(xref, i);
n = fz_read(xref->file, (unsigned char *) buf->scratch, 20);
if (n < 0)
fz_throw(xref->ctx, "cannot read xref table");
@@ -296,7 +430,7 @@ pdf_read_new_xref_section(pdf_document *xref, fz_stream *stm, int i0, int i1, in
for (i = i0; i < i0 + i1; i++)
{
- pdf_xref_entry *entry = pdf_get_xref_entry(xref, i);
+ pdf_xref_entry *entry = pdf_get_populating_xref_entry(xref, i);
int a = 0;
int b = 0;
int c = 0;
@@ -342,7 +476,7 @@ pdf_read_new_xref(pdf_document *xref, pdf_lexbuf *buf)
pdf_xref_entry *entry;
int ofs = fz_tell(xref->file);
trailer = pdf_parse_ind_obj(xref, xref->file, buf, &num, &gen, &stm_ofs);
- entry = pdf_get_xref_entry(xref, num);
+ entry = pdf_get_populating_xref_entry(xref, num);
entry->ofs = ofs;
entry->gen = gen;
entry->stm_ofs = stm_ofs;
@@ -363,7 +497,7 @@ pdf_read_new_xref(pdf_document *xref, pdf_lexbuf *buf)
size = pdf_to_int(obj);
/* Access xref entry to assure table size */
- (void)pdf_get_xref_entry(xref, size-1);
+ (void)pdf_get_populating_xref_entry(xref, size-1);
if (num < 0 || num >= pdf_xref_len(xref))
fz_throw(ctx, "object id (%d %d R) out of range (0..%d)", num, gen, pdf_xref_len(xref) - 1);
@@ -490,9 +624,7 @@ read_xref_section(pdf_document *xref, int ofs, pdf_lexbuf *buf, ofs_list *offset
trailer = pdf_read_xref(xref, ofs, buf);
- /* Currently we only store the trailer most recently added to the doc */
- if (!pdf_trailer(xref))
- pdf_set_xref_trailer(xref, trailer);
+ pdf_set_populating_xref_trailer(xref, trailer);
/* FIXME: do we overwrite free entries properly? */
xrefstmofs = pdf_to_int(pdf_dict_gets(trailer, "XRefStm"));
@@ -537,7 +669,10 @@ pdf_read_xref_sections(pdf_document *xref, int ofs, pdf_lexbuf *buf)
fz_try(ctx)
{
while(ofs)
+ {
+ pdf_populate_next_xref_level(xref);
ofs = read_xref_section(xref, ofs, buf, &list);
+ }
}
fz_always(ctx)
{
@@ -775,8 +910,7 @@ pdf_init_document(pdf_document *xref)
}
fz_catch(ctx)
{
- pdf_replace_xref(xref, NULL, 0);
- pdf_set_xref_trailer(xref, NULL);
+ pdf_free_xref_sections(xref);
fz_warn(xref->ctx, "trying to repair broken xref");
repaired = 1;
}
@@ -871,7 +1005,7 @@ pdf_init_document(pdf_document *xref)
void
pdf_close_document(pdf_document *xref)
{
- int i, xref_len;
+ int i;
fz_context *ctx;
if (!xref)
@@ -880,18 +1014,7 @@ pdf_close_document(pdf_document *xref)
pdf_drop_js(xref->js);
- xref_len = pdf_xref_len(xref);
- for (i = 0; i < xref_len; i++)
- {
- pdf_xref_entry *entry = pdf_get_xref_entry(xref, i);
- if (entry->obj)
- {
- pdf_drop_obj(entry->obj);
- entry->obj = NULL;
- fz_drop_buffer(ctx, entry->stm_buf);
- }
- }
- pdf_replace_xref(xref, NULL, 0);
+ pdf_free_xref_sections(xref);
if (xref->page_objs)
{
@@ -911,7 +1034,6 @@ pdf_close_document(pdf_document *xref)
pdf_drop_obj(xref->focus_obj);
if (xref->file)
fz_close(xref->file);
- pdf_drop_obj(pdf_trailer(xref));
if (xref->crypt)
pdf_free_crypt(ctx, xref->crypt);
@@ -1192,7 +1314,7 @@ pdf_create_object(pdf_document *xref)
/* TODO: reuse free object slots by properly linking free object chains in the ofs field */
pdf_xref_entry *entry;
int num = pdf_xref_len(xref);
- entry = pdf_get_xref_entry(xref, num);
+ entry = pdf_get_new_xref_entry(xref, num);
entry->type = 'f';
entry->ofs = -1;
entry->gen = 0;
@@ -1213,7 +1335,7 @@ pdf_delete_object(pdf_document *xref, int num)
return;
}
- x = pdf_get_xref_entry(xref, num);
+ x = pdf_get_new_xref_entry(xref, num);
fz_drop_buffer(xref->ctx, x->stm_buf);
pdf_drop_obj(x->obj);
@@ -1237,7 +1359,7 @@ pdf_update_object(pdf_document *xref, int num, pdf_obj *newobj)
return;
}
- x = pdf_get_xref_entry(xref, num);
+ x = pdf_get_new_xref_entry(xref, num);
pdf_drop_obj(x->obj);
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-12 15:03:13 +0000