typedef struct pdf_xref pdf_xref
typedef struct pdf_ocg_descriptor pdf_ocg_descriptor
typedef struct pdf_page pdf_page
typedef struct pdf_annot pdf_annot
typedef struct pdf_js pdf_js
#define PDF_LEXBUF_SMALL 256
#define PDF_LEXBUF_LARGE 65536
struct pdf_lexbuf
{
size_t size;
size_t base_size;
size_t len;
int64_t i;
float f;
char *scratch;
char buffer[PDF_LEXBUF_SMALL];
}
struct pdf_lexbuf_large
{
pdf_lexbuf base;
char buffer[PDF_LEXBUF_LARGE - PDF_LEXBUF_SMALL];
}
typedef struct pdf_doc_event pdf_doc_event
Document event structures are mostly opaque to the app. Only the type is visible to the app.
typedef void (pdf_doc_event_cb)(fz_context *ctx, pdf_document *doc, pdf_doc_event *evt, void *data)
the type of function via which the app receives document events.
typedef void (pdf_free_doc_event_data_cb)(fz_context *ctx, void *data)
the type of function via which the app frees the data provided to the event callback pdf_doc_event_cb.
typedef void (pdf_js_console_drop_cb)(pdf_js_console *console, void *user)
Callback called when the console is dropped because it is being replaced or the javascript is being disabled by a call to pdf_disable_js().
typedef void (pdf_js_console_show_cb)(void *user)
Callback signalling that a piece of javascript is asking the javascript console to be displayed.
typedef void (pdf_js_console_hide_cb)(void *user)
Callback signalling that a piece of javascript is asking the javascript console to be hidden.
typedef void (pdf_js_console_clear_cb)(void *user)
Callback signalling that a piece of javascript is asking the javascript console to remove all its contents.
typedef void (pdf_js_console_write_cb)(void *user, const char *msg)
Callback signalling that a piece of javascript is appending the given message to the javascript console contents.
struct pdf_js_console {
pdf_js_console_drop_cb *drop;
pdf_js_console_show_cb *show;
pdf_js_console_hide_cb *hide;
pdf_js_console_clear_cb *clear;
pdf_js_console_write_cb *write;
}
The callback functions relating to a javascript console.
pdf_js_console *
pdf_js_get_console (
fz_context *ctx,
pdf_document *doc
)
Retrieve the currently set javascript console, or NULL if none is set.
void
pdf_js_set_console (
fz_context *ctx,
pdf_document *doc,
pdf_js_console *console,
void *user
)
Set a new javascript console.
pdf_document *
pdf_open_document (
fz_context *ctx,
const char *filename
)
Open a PDF document.
Open a PDF document by reading its cross reference table, so MuPDF can locate PDF objects inside the file. Upon an broken cross reference table or other parse errors MuPDF will restart parsing the file from the beginning to try to rebuild a (hopefully correct) cross reference table to allow further processing of the file.
The returned pdf_document should be used when calling most other PDF functions. Note that it wraps the context, so those functions implicitly get access to the global state in context.
pdf_document *
pdf_open_document_with_dir (
fz_context *ctx,
const char *filename,
fz_archive *dir
)
Open a PDF document with an archive. If the archive is non-NULL, the filename will be searched for inside the archive, as will any external files. Otherwise the document will be loaded from the standard filing system, and no external file access will be allowed.
Same as pdf_open_document, but with the addition of an archive.
A reference is taken to the archive.
pdf_document *
pdf_open_document_with_stream (
fz_context *ctx,
fz_stream *file
)
Opens a PDF document.
Same as pdf_open_document, but takes a stream instead of a filename to locate the PDF document to open. Increments the reference count of the stream. See fz_open_file, fz_open_file_w or fz_open_fd for opening a stream, and fz_drop_stream for closing an open stream.
pdf_document *
pdf_open_document_with_stream_and_dir (
fz_context *ctx,
fz_stream *file,
fz_archive *dir
)
Like pdf_open_document_with_stream, but in addition an archive is passed in which external resources may be looked for.
A reference will be taken to the archive.
void
pdf_drop_document (
fz_context *ctx,
pdf_document *doc
)
Closes and frees an opened PDF document.
The resource store in the context associated with pdf_document is emptied.
pdf_document *
pdf_keep_document (
fz_context *ctx,
pdf_document *doc
)
int
pdf_check_document (
fz_context *ctx,
pdf_document *doc
)
Do a pass through the document to check if it needs any repairs; and trigger a repair if necessary.
This is a very expensive operation both in terms of memory use and computation, because it needs to parse the entire file to detect any errors.
The result of the check is saved, so calling this function again after a successful completion is a no-op.
If this function throws (either because of out of memory (SYSTEM), or other reasons) then the file should be considered suspect.
Returns non-zero if a repair was triggered during checking, and hence changes to the file may have been lost.
pdf_document *
pdf_specifics (
fz_context *ctx,
fz_document *doc
)
down-cast a fz_document to a pdf_document. Returns NULL if underlying document is not PDF
pdf_document *
pdf_document_from_fz_document (
fz_context *ctx,
fz_document *ptr
)
Down-cast generic fitz objects into pdf specific variants. Returns NULL if the objects are not from a PDF document.
pdf_page *
pdf_page_from_fz_page (
fz_context *ctx,
fz_page *ptr
)
pdf_document *
fz_new_pdf_document_from_fz_document (
fz_context *ctx,
fz_document *ptr
)
Get a pdf_document handle from an fz_document handle.
This is superficially similar to pdf_document_from_fz_document (and the older pdf_specifics).
For fz_documents that are actually pdf_documents, this will return a kept version of the same pointer, just cast differently.
For fz_documents that have a pdf_document representation internally, then you may get a kept version of a different pointer.
For fz_documents that have no pdf_document representation internally, this will return NULL.
Note that this returns a kept pointer that the caller is responsible for freeing, unlike pdf_specifics or pdf_document_from_fz_document.
int
pdf_needs_password (
fz_context *ctx,
pdf_document *doc
)
int
pdf_authenticate_password (
fz_context *ctx,
pdf_document *doc,
const char *pw
)
Attempt to authenticate a password.
Returns 0 for failure, non-zero for success.
In the non-zero case: bit 0 set => no password required bit 1 set => user password authenticated bit 2 set => owner password authenticated
int
pdf_has_permission (
fz_context *ctx,
pdf_document *doc,
fz_permission p
)
int
pdf_lookup_metadata (
fz_context *ctx,
pdf_document *doc,
const char *key,
char *ptr,
size_t size
)
fz_outline *
pdf_load_outline (
fz_context *ctx,
pdf_document *doc
)
fz_outline_iterator *
pdf_new_outline_iterator (
fz_context *ctx,
pdf_document *doc
)
void
pdf_invalidate_xfa (
fz_context *ctx,
pdf_document *doc
)
int
pdf_count_layer_configs (
fz_context *ctx,
pdf_document *doc
)
Get the number of layer configurations defined in this document.
int
pdf_count_layers (
fz_context *ctx,
pdf_document *doc
)
Configure visibility of individual layers in this document.
const char *
pdf_layer_name (
fz_context *ctx,
pdf_document *doc,
int layer
)
int
pdf_layer_is_enabled (
fz_context *ctx,
pdf_document *doc,
int layer
)
void
pdf_enable_layer (
fz_context *ctx,
pdf_document *doc,
int layer,
int enabled
)
struct pdf_layer_config
{
const char *name;
const char *creator;
}
void
pdf_layer_config_info (
fz_context *ctx,
pdf_document *doc,
int config_num,
pdf_layer_config *info
)
Fetch the name (and optionally creator) of the given layer config.
const char *
pdf_layer_config_creator (
fz_context *ctx,
pdf_document *doc,
int config_num
)
Fetch the creator of the given layer config, or NULL if none exists.
const char *
pdf_layer_config_name (
fz_context *ctx,
pdf_document *doc,
int config_num
)
Fetch the name of the given layer config, or NULL if none exists.
void
pdf_select_layer_config (
fz_context *ctx,
pdf_document *doc,
int config_num
)
Set the current configuration. This updates the visibility of the optional content groups within the document.
int
pdf_count_layer_config_ui (
fz_context *ctx,
pdf_document *doc
)
Returns the number of entries in the ‘UI’ for this layer configuration.
void
pdf_select_layer_config_ui (
fz_context *ctx,
pdf_document *doc,
int ui
)
Select a checkbox/radiobox within the ‘UI’ for this layer configuration.
Selecting a UI entry that is a radiobox may disable other UI entries.
void
pdf_deselect_layer_config_ui (
fz_context *ctx,
pdf_document *doc,
int ui
)
Select a checkbox/radiobox within the ‘UI’ for this layer configuration.
void
pdf_toggle_layer_config_ui (
fz_context *ctx,
pdf_document *doc,
int ui
)
Toggle a checkbox/radiobox within the ‘UI’ for this layer configuration.
Toggling a UI entry that is a radiobox may disable other UI entries.
enum pdf_layer_config_ui_type
{
PDF_LAYER_UI_LABEL = 0,
PDF_LAYER_UI_CHECKBOX = 1,
PDF_LAYER_UI_RADIOBOX = 2
}
const char *
pdf_layer_config_ui_type_to_string (
pdf_layer_config_ui_type type
)
pdf_layer_config_ui_type
pdf_layer_config_ui_type_from_string (
const char *str
)
struct pdf_layer_config_ui
{
const char *text;
int depth;
pdf_layer_config_ui_type type;
int selected;
int locked;
}
void
pdf_layer_config_ui_info (
fz_context *ctx,
pdf_document *doc,
int ui,
pdf_layer_config_ui *info
)
Get the info for a given entry in the layer config ui.
void
pdf_set_layer_config_as_default (
fz_context *ctx,
pdf_document *doc
)
Write the current layer config back into the document as the default state.
int
pdf_has_unsaved_changes (
fz_context *ctx,
pdf_document *doc
)
Determine whether changes have been made since the document was opened or last saved.
int
pdf_was_repaired (
fz_context *ctx,
pdf_document *doc
)
Determine if this PDF has been repaired since opening.
typedef struct pdf_pkcs7_signer pdf_pkcs7_signer
Object that can perform the cryptographic operation necessary for document signing
struct pdf_unsaved_sig
{
pdf_obj *field;
size_t byte_range_start;
size_t byte_range_end;
size_t contents_start;
size_t contents_end;
pdf_pkcs7_signer *signer;
struct pdf_unsaved_sig *next;
}
Unsaved signature fields
struct pdf_rev_page_map
{
int page;
int object;
}
struct pdf_hint_page
{
int number; /* Page object number */
int64_t offset; /* Offset of page object */
int64_t index; /* Index into shared hint_shared_ref */
}
struct pdf_hint_shared
{
int number; /* Object number of first object */
int64_t offset; /* Offset of first object */
}
struct pdf_document
{
fz_document super;
fz_stream *file;
int version;
int checked; /* we've checked that we don't need to repair */
int is_fdf;
int bias;
int64_t startxref;
int64_t file_size;
pdf_crypt *crypt;
pdf_ocg_descriptor *ocg;
fz_colorspace *oi;
int max_xref_len;
int num_xref_sections;
int saved_num_xref_sections;
int num_incremental_sections;
int xref_base;
int disallow_new_increments;
/* The local_xref is only active, if local_xref_nesting >= 0 */
pdf_xref *local_xref;
int local_xref_nesting;
pdf_xref *xref_sections;
pdf_xref *saved_xref_sections;
int *xref_index;
int save_in_progress;
int last_xref_was_old_style;
int has_linearization_object;
int map_page_count;
pdf_rev_page_map *rev_page_map;
pdf_obj **fwd_page_map;
int use_page_tree_map;
int repair_attempted;
int repair_in_progress;
int non_structural_change; /* True if we are modifying the document in a way that does not change the (page) structure */
int struct_tree_repaired;
int struct_tree_result;
/* State indicating which file parsing method we are using */
int file_reading_linearly;
int64_t file_length;
int linear_page_count;
pdf_obj *linear_obj; /* Linearized object (if used) */
pdf_obj **linear_page_refs; /* Page objects for linear loading */
int linear_page1_obj_num;
/* The state for the pdf_progressive_advance parser */
int64_t linear_pos;
int linear_page_num;
int hint_object_offset;
int hint_object_length;
int hints_loaded; /* Set to 1 after the hints loading has completed,
* whether successful or not! */
/* Page n references shared object references:
* hint_shared_ref[i]
* where
* i = s to e-1
* s = hint_page[n]->index
* e = hint_page[n+1]->index
* Shared object reference r accesses objects:
* rs to re-1
* where
* rs = hint_shared[r]->number
* re = hint_shared[r]->count + rs
* These are guaranteed to lie within the region starting at
* hint_shared[r]->offset of length hint_shared[r]->length
*/
pdf_hint_page *hint_page;
int *hint_shared_ref;
pdf_hint_shared *hint_shared;
int hint_obj_offsets_max;
int64_t *hint_obj_offsets;
pdf_lexbuf_large lexbuf;
pdf_js *js;
int recalculate;
int redacted;
int resynth_required;
pdf_doc_event_cb *event_cb;
pdf_free_doc_event_data_cb *free_event_data_cb;
void *event_cb_data;
fz_list(fz_font *, type3_fonts);
struct {
fz_hash_table *fonts;
fz_hash_table *colorspaces;
fz_hash_table *images;
} resources;
int orphans_max;
int orphans_count;
pdf_obj **orphans;
fz_xml_doc *xfa;
pdf_journal *journal;
int throw_on_repair;
fz_archive *archive;
}
pdf_document *
pdf_create_document (
fz_context *ctx
)
typedef struct pdf_graft_map pdf_graft_map
pdf_obj *
pdf_graft_object (
fz_context *ctx,
pdf_document *dst,
pdf_obj *obj
)
Return a deep copied object equivalent to the supplied object, suitable for use within the given document.
Note: If grafting multiple objects, you should use a pdf_graft_map to avoid potential duplication of target objects.
pdf_graft_map *
pdf_new_graft_map (
fz_context *ctx,
pdf_document *dst
)
Prepare a graft map object to allow objects to be deep copied from one document to the given one, avoiding problems with duplicated child objects.
Note: all the source objects must come from the same document.
pdf_graft_map *
pdf_keep_graft_map (
fz_context *ctx,
pdf_graft_map *map
)
void
pdf_drop_graft_map (
fz_context *ctx,
pdf_graft_map *map
)
pdf_obj *
pdf_graft_mapped_object (
fz_context *ctx,
pdf_graft_map *map,
pdf_obj *obj
)
Return a deep copied object equivalent to the supplied object, suitable for use within the target document of the map.
Note: Copying multiple objects via the same graft map ensures that any shared children are not copied more than once.
void
pdf_graft_page (
fz_context *ctx,
pdf_document *dst,
int page_to,
pdf_document *src,
int page_from
)
Graft a page (and its resources) from the src document to the destination document of the graft. This involves a deep copy of the objects in question.
void
pdf_graft_mapped_page (
fz_context *ctx,
pdf_graft_map *map,
int page_to,
pdf_document *src,
int page_from
)
fz_device *
pdf_page_write (
fz_context *ctx,
pdf_document *doc,
fz_rect mediabox,
pdf_obj **presources,
fz_buffer **pcontents
)
Create a device that will record the graphical operations given to it into a sequence of pdf operations, together with a set of resources. This sequence/set pair can then be used as the basis for adding a page to the document (see pdf_add_page). Returns a kept reference.
fz_device *
pdf_new_pdf_device (
fz_context *ctx,
pdf_document *doc,
fz_matrix topctm,
pdf_obj *resources,
fz_buffer *contents
)
Create a pdf device. Rendering to the device creates new pdf content. WARNING: this device is work in progress. It doesn’t currently support all rendering cases.
Note that contents must be a stream (dictionary) to be updated (or a reference to a stream). Callers should take care to ensure that it is not an array, and that is it not shared with other objects/pages.
pdf_obj *
pdf_add_page (
fz_context *ctx,
pdf_document *doc,
fz_rect mediabox,
int rotate,
pdf_obj *resources,
fz_buffer *contents
)
Create a pdf_obj within a document that represents a page, from a previously created resources dictionary and page content stream. This should then be inserted into the document using pdf_insert_page.
After this call the page exists within the document structure, but is not actually ever displayed as it is not linked into the PDF page tree.
void
pdf_insert_page (
fz_context *ctx,
pdf_document *doc,
int at,
pdf_obj *page
)
Insert a page previously created by pdf_add_page into the pages tree of the document.
void
pdf_delete_page (
fz_context *ctx,
pdf_document *doc,
int number
)
Delete a page from the page tree of a document. This does not remove the page contents or resources from the file.
void
pdf_delete_page_range (
fz_context *ctx,
pdf_document *doc,
int start,
int end
)
Delete a range of pages from the page tree of a document. This does not remove the page contents or resources from the file.
void
pdf_page_label (
fz_context *ctx,
pdf_document *doc,
int page,
char *buf,
size_t size
)
Get page label (string) from a page number (index).
void
pdf_page_label_imp (
fz_context *ctx,
fz_document *doc,
int chapter,
int page,
char *buf,
size_t size
)
enum pdf_page_label_style
{
PDF_PAGE_LABEL_NONE = 0,
PDF_PAGE_LABEL_DECIMAL = 'D',
PDF_PAGE_LABEL_ROMAN_UC = 'R',
PDF_PAGE_LABEL_ROMAN_LC = 'r',
PDF_PAGE_LABEL_ALPHA_UC = 'A',
PDF_PAGE_LABEL_ALPHA_LC = 'a',
}
void
pdf_set_page_labels (
fz_context *ctx,
pdf_document *doc,
int index,
pdf_page_label_style style,
const char *prefix,
int start
)
void
pdf_delete_page_labels (
fz_context *ctx,
pdf_document *doc,
int index
)
fz_text_language
pdf_document_language (
fz_context *ctx,
pdf_document *doc
)
void
pdf_set_document_language (
fz_context *ctx,
pdf_document *doc,
fz_text_language lang
)
struct pdf_write_options
{
int do_incremental; /* Write just the changed objects. */
int do_pretty; /* Pretty-print dictionaries and arrays. */
int do_ascii; /* ASCII hex encode binary streams. */
int do_compress; /* Compress streams. 1 zlib, 2 brotli */
int do_compress_images; /* Compress (or leave compressed) image streams. */
int do_compress_fonts; /* Compress (or leave compressed) font streams. */
int do_decompress; /* Decompress streams (except when compressing images/fonts). */
int do_garbage; /* Garbage collect objects before saving; 1=gc, 2=re-number, 3=de-duplicate. */
int do_linear; /* Write linearised. */
int do_clean; /* Clean content streams. */
int do_sanitize; /* Sanitize content streams. */
int do_appearance; /* (Re)create appearance streams. */
int do_encrypt; /* Encryption method to use: keep, none, rc4-40, etc. */
int dont_regenerate_id; /* Don't regenerate ID if set (used for clean) */
int permissions; /* Document encryption permissions. */
char opwd_utf8[128]; /* Owner password. */
char upwd_utf8[128]; /* User password. */
int do_snapshot; /* Do not use directly. Use the snapshot functions. */
int do_preserve_metadata; /* When cleaning, preserve metadata unchanged. */
int do_use_objstms; /* Use objstms if possible */
int compression_effort; /* 0 for default. 100 = max, 1 = min. */
int do_labels; /* Add labels to each object showing how it can be reached from the Root. */
int reproducible; /* Attempt to make operations 'reproducible'. For example, avoid writing MuPDF version number. */
}
In calls to fz_save_document, the following options structure can be used to control aspects of the writing process. This structure may grow in the future, and should be zero-filled to allow forwards compatibility.
extern const pdf_write_options pdf_default_write_options
pdf_write_options *
pdf_parse_write_options (
fz_context *ctx,
pdf_write_options *opts,
const char *args
)
Parse option string into a pdf_write_options struct. Matches the command line options to ‘mutool clean’: g: garbage collect d, i, f: expand all, fonts, images l: linearize a: ascii hex encode z: deflate c: clean content streams s: sanitize content streams
void
pdf_init_write_options (
fz_context *ctx,
pdf_write_options *opts
)
void
pdf_apply_write_options (
fz_context *ctx,
pdf_write_options *opts,
fz_options *args
)
int
pdf_has_unsaved_sigs (
fz_context *ctx,
pdf_document *doc
)
Returns true if there are digital signatures waiting to to updated on save.
void
pdf_write_document (
fz_context *ctx,
pdf_document *doc,
fz_output *out,
const pdf_write_options *opts
)
Write out the document to an output stream with all changes finalised.
void
pdf_save_document (
fz_context *ctx,
pdf_document *doc,
const char *filename,
const pdf_write_options *opts
)
Write out the document to a file with all changes finalised.
void
pdf_save_snapshot (
fz_context *ctx,
pdf_document *doc,
const char *filename
)
Snapshot the document to a file. This does not cause the incremental xref to be finalized, so the document in memory remains (essentially) unchanged.
void
pdf_write_snapshot (
fz_context *ctx,
pdf_document *doc,
fz_output *out
)
Snapshot the document to an output stream. This does not cause the incremental xref to be finalized, so the document in memory remains (essentially) unchanged.
char *
pdf_format_write_options (
fz_context *ctx,
char *buffer,
size_t buffer_len,
const pdf_write_options *opts
)
int
pdf_can_be_saved_incrementally (
fz_context *ctx,
pdf_document *doc
)
Return true if the document can be saved incrementally. Applying redactions or having a repaired document make incremental saving impossible.
void
pdf_write_journal (
fz_context *ctx,
pdf_document *doc,
fz_output *out
)
Write out the journal to an output stream.
void
pdf_save_journal (
fz_context *ctx,
pdf_document *doc,
const char *filename
)
Write out the journal to a file.
void
pdf_load_journal (
fz_context *ctx,
pdf_document *doc,
const char *filename
)
Read a journal from a filename. Will do nothing if the journal does not match. Will throw on a corrupted journal.
void
pdf_read_journal (
fz_context *ctx,
pdf_document *doc,
fz_stream *stm
)
Read a journal from a stream. Will do nothing if the journal does not match. Will throw on a corrupted journal.
void
pdf_minimize_document (
fz_context *ctx,
pdf_document *doc
)
Minimize the memory used by a document.
We walk the in memory xref tables, evicting the PDF objects therein that aren’t in use.
This reduces the current memory use, but any subsequent use of these objects will load them back into memory again.
fz_structure
pdf_structure_type (
fz_context *ctx,
pdf_obj *role_map,
pdf_obj *tag
)
Map a pdf object representing a structure tag through an optional role_map and convert to an fz_structure.
void
pdf_run_document_structure (
fz_context *ctx,
pdf_document *doc,
fz_device *dev,
fz_cookie *cookie
)
Run the document structure to a device.
int
pdf_count_document_associated_files (
fz_context *ctx,
pdf_document *doc
)
Return the count of the associated files on a document. Note, that this is the count of files associated at the document level and does not necessarily include files associated at other levels.
pdf_obj *
pdf_document_associated_file (
fz_context *ctx,
pdf_document *doc,
int idx
)
Return a borrowed pointer to the PDF object that represents a given associated file on a document.
Indexed from 0 to count-1.
int
pdf_count_page_associated_files (
fz_context *ctx,
pdf_page *page
)
Return the count of the associated files on a given page. Note, that this is the count of files associated at the page level and does not necessarily include files associated at other levels.
pdf_obj *
pdf_page_associated_file (
fz_context *ctx,
pdf_page *page,
int idx
)
Return a borrowed pointer to the PDF object that represents a given associated file on a page.
Indexed from 0 to count-1.
typedef struct pdf_object_labels pdf_object_labels
A structure used to create “labels” for numbered objects. The labels are different ways to reach an object from the trailer and page tree, using the “mutool show” syntax.
Note: Paths involving “Parent”, “P”, “Prev”, and “Last” are ignored, as these are used for cycles in the structures which we don’t care about labeling.
pdf_object_labels *
pdf_load_object_labels (
fz_context *ctx,
pdf_document *doc
)
Scan the entire object structure to create a directed graph of indirect numbered objects and how they can reach each other.
void
pdf_drop_object_labels (
fz_context *ctx,
pdf_object_labels *g
)
typedef void (pdf_label_object_fn)(fz_context *ctx, void *arg, const char *label)
Enumerate all the possible labels for a given numbered object. The callback is invoked with a path for each possible way the object can be reached from the PDF trailer.
void
pdf_label_object (
fz_context *ctx,
pdf_object_labels *g,
int num,
pdf_label_object_fn *callback,
void *arg
)
enum pdf_check_structure_result
{
PDF_STRUCT_NOT_PRESENT = 0,
/* A struct tree is present in the file. */
PDF_STRUCT_PRESENT = 1,
/* The struct tree is unrepairably broken. */
PDF_STRUCT_BROKEN = 2,
/* A problem was found, but was fixed. */
PDF_STRUCT_FIXED = 4,
/* The Struct tree contains attributes. */
PDF_STRUCT_HAS_ATTRIBUTES = 8,
/* The Struct tree contains Table attributes. */
PDF_STRUCT_HAS_TABLE_ATTRIBUTES = 16,
/* The Struct tree contains Table cell spanning attributes. */
PDF_STRUCT_HAS_TABLE_SPAN_ATTRIBUTES = 32,
/* The Struct tree contains a cycle. */
PDF_STRUCT_HAS_CYCLE = 64
}
pdf_check_structure_result
pdf_check_structure_tree (
fz_context *ctx,
pdf_document *doc
)
Run a validation pass over the structure tree, and attempt to repair any problems found. Also returns information about the state of the tree.
Returns a code with bits set as above.
Helper functions to modify what happens when a repair is kicked off. Most of the time the transparent repair magic works fine, but if a repair happens this can invalidate some pointers held to internal structures.
To cope with this, we allow the document to be put into a state whereby any repair will trigger an exception (FZ_ERROR_REPAIRED) after any repair.
Code can therefore use this mechanism to safely catch and retry complete operations if a repair occurs.
Because this mechanism is so frequently used when altering xref_base, we build the xref_base store/restore into these functions.
The pattern of code is therefore as follows:
void pdf_do_some_operation(fz_context *ctx, pdf_document *doc, ...)
{
int xref_base; // Variable to store the initial xref_base value
int repaired = 0;
retry_on_repair:
pdf_start_throw_on_repair(ctx, doc, &xref_base);
fz_try(ctx)
{
// Actual operation goes here. This may involved changing
// doc->xref_base. e.g. doc->xref_base = initial
}
fz_always(ctx)
pdf_end_throw_on_repair(ctx, doc, xref_base);
fz_catch(ctx)
{
if (fz_caught(ctx) == FZ_ERROR_REPAIRED)
{
fz_report_error(ctx);
repaired = 1;
// doc->xref_base will always have been reset to be something legal
// here, but if you have been passed in an xref level to operate at
// you may want to check that that level is still valid here!
// e.g. if (initial >= doc->num_xref_sections) return;
goto retry_on_repair;
}
fz_rethrow(ctx);
}
// If we repaired, then we swallowed the exception. There may have been callers above
// us that were wanting to be informed. This call takes care of that if required.
if (repaired)
pdf_maybe_throw_after_repair(ctx, doc);
}
void
pdf_start_throw_on_repair (
fz_context *ctx,
pdf_document *doc,
int *xref_base
)
Prepare for an operation that can’t easily be interrupted by a repair, and should instead be retried.
See above for example code.
void
pdf_end_throw_on_repair (
fz_context *ctx,
pdf_document *doc,
int xref_base
)
Mark the end of an operation that can’t easily be interrupted by a repair, and should instead be retried.
See above for example code.
void
pdf_maybe_throw_after_repair (
fz_context *ctx,
pdf_document *doc
)
If a caller of ours is expecting an exception on a repair, give them one.