module Pdf:sig
..end
Representing PDF Files in Memory
type
toget
type
stream =
| |
Got of |
| |
ToGet of |
A stream is either in memory, or at a position and of a length in an
Pdfio.input
.
type
pdfobject =
| |
Null |
| |
Boolean of |
| |
Integer of |
| |
Real of |
| |
String of |
| |
Name of |
| |
Array of |
| |
Dictionary of |
| |
Stream of |
| |
Indirect of |
PDF objects. An object is a tree-like structure containing various things. A PDF file is basically a directed graph of objects.
You should not expect to manipulate these types and functions directly.
type
objectdata =
| |
Parsed of |
| |
ParsedAlreadyDecrypted of |
| |
ToParse |
| |
ToParseFromObjectStream of |
This type represents a possibly-parsed, possibly-decrypted, possibly-read-from-an-object-stream object.
typepdfobjmap_key =
int
typepdfobjmap =
(pdfobjmap_key, objectdata Stdlib.ref * int) Stdlib.Hashtbl.t
The object map maps object numbers pdfobjmap_key
to a reference to the
object data and the generation number
val pdfobjmap_empty : unit -> pdfobjmap
Make an empty object map
val pdfobjmap_find : pdfobjmap_key -> pdfobjmap -> objectdata Stdlib.ref * int
Find an object in the object map
type
pdfobjects = {
|
mutable maxobjnum : |
|
mutable parse : |
|
mutable pdfobjects : |
|
mutable object_stream_ids : |
}
The objects. Again, you won't normally manipulate this directly.
maxobjnum
is the biggest object number seen yet. parse
is a function to
parse a non-object stream object given its object number, pdfobjects
is the
object map itself. object_stream_ids
is a hash table of (object number,
was-stored-in-obect-stream-number) pairs, which is used to reconstruct stream
objects when preserving them upon write.
type
saved_encryption = {
|
from_get_encryption_values : |
|
encrypt_metadata : |
|
perms : |
}
type
deferred_encryption = {
|
crypt_type : |
|
file_encryption_key : |
|
obj : |
|
gen : |
|
key : |
|
keylength : |
|
r : |
}
type
t = {
|
mutable major : |
|
mutable minor : |
|
mutable root : |
|
mutable objects : |
|
mutable trailerdict : |
|
mutable was_linearized : |
|
mutable saved_encryption : |
}
A Pdf document. Major and minor version numbers, object number of root, the
objects objects and the trailer dictionary as a Dictionary
pdfobject
.
val empty : unit -> t
The empty document (PDF 1.0, no objects, no root, empty trailer dictionary). Note this is not a well-formed PDF.
exception PDFError of string
This exception is raised when some malformity in a PDF is found -- quite a wide range of circumstances, and may be raised from many functions.
val input_pdferror : Pdfio.input -> string -> string
This function, given a Pdfio.input
and an ancilliary string, builds an
error string which includes the source of the Pdfio.input (filename, string,
bytes etc) so we can trace what it was originally built from
val getstream : pdfobject -> unit
Get a stream from disc if it hasn't already been got. The input is a
Stream pdfobject
.
val getnum : t -> pdfobject -> float
Return a float from a Real
, an Int
or an Indirect
val lookup_obj : t -> int -> pdfobject
Lookup an object in a document, parsing it if required. Raises Not_found
if the object does not exist.
val lookup_fail : string -> t -> string -> pdfobject -> pdfobject
lookup_fail errtext doc key dict
looks up a key in a PDF dictionary or the
dictionary of a PDF stream. Fails with PDFError errtext
if the key is not
found. Follows indirect object links.
val lookup_exception : exn -> t -> string -> pdfobject -> pdfobject
Same, but with customised exception.
val lookup_direct : t -> string -> pdfobject -> pdfobject option
lookup_direct doc key dict
looks up the key, resolving indirections at
source and destination, returning an option type.
val lookup_immediate : string -> pdfobject -> pdfobject option
lookup_immediate key dict
looks up the key returning the value, without
following indirects at either source or destination.
val lookup_chain : t -> pdfobject -> string list -> pdfobject option
lookup_chain doc start keys
looks up the key in a nested dictionary. For
example lookup_chain pdf pdf.Pdf.trailerdict ["/Root"; "/StructTreeRoot";
"/RoleMap"]
val indirect_number : t -> string -> pdfobject -> int option
Return the object number of an indirect dictionary object, if it is indirect.
val lookup_direct_orelse : t -> string -> string -> pdfobject -> pdfobject option
Same as lookup_direct
, but allow a second, alternative key.
val remove_dict_entry : pdfobject -> string -> pdfobject
Remove a dictionary entry, if it exists.
val replace_dict_entry : pdfobject -> string -> pdfobject -> pdfobject
replace_dict_entry dict key value
replaces a dictionary entry, raising Not_found
if it's not there.
val add_dict_entry : pdfobject -> string -> pdfobject -> pdfobject
add_dict_entry dict key value
adds a dictionary entry, replacing if already there.
val direct : t -> pdfobject -> pdfobject
Make a PDF object direct -- that is, follow any indirect links.
val objcard : t -> int
Return the size of the object map.
val removeobj : t -> int -> unit
Remove the given object
val addobj : t -> pdfobject -> int
Add an object. Returns the number chosen.
val addobj_given_num : t -> int * pdfobject -> unit
Same as addobj
, but pick a number ourselves.
val parse_rectangle : t -> pdfobject -> float * float * float * float
Parse a PDF rectangle structure into min x, min y, max x, max y.
val parse_matrix : t -> string -> pdfobject -> Pdftransform.transform_matrix
Calling parse_matrix pdf name dict
parses a PDF matrix found under
key name
in dictionary dict
into a Transform.transform_matrix
. If there is
no matrix, the identity matrix is returned.
val make_matrix : Pdftransform.transform_matrix -> pdfobject
Build a matrix pdfobject
.
val renumber_pdfs : t list -> t list
Make a number of PDF documents contain no mutual object numbers. They can then be merged etc. without clashes.
val unique_key : string -> pdfobject -> string
Given a dictionary and a prefix (e.g gs), return a name, starting with the prefix, which is not already in the dictionary (e.g /gs0).
val objiter : (int -> pdfobject -> unit) -> t -> unit
Iterate over the objects in a document. The iterating functions recieves both object number and object from the object map.
val objiter_inorder : (int -> pdfobject -> unit) -> t -> unit
The same, but in object number order.
val objiter_gen : (int -> int -> pdfobject -> unit) -> t -> unit
Iterate over the objects in a document. The iterating functions recieves object number, generation number and object from the object map.
val objselfmap : (pdfobject -> pdfobject) -> t -> unit
Map over all pdf objects in a document. Does not include trailer dictionary.
val iter_stream : (pdfobject -> unit) -> t -> unit
Iterate over just the stream objects in a document.
val remove_unreferenced : t -> unit
Garbage-collect a pdf document.
These functions were previsouly undocumented. They are documented here for now, and in the future will be categorised more sensibly.
val is_whitespace : char -> bool
True if a character is PDF whitespace.
val is_not_whitespace : char -> bool
True if a character is not PDF whitespace.
val is_delimiter : char -> bool
True if a character is a PDF delimiter.
val page_reference_numbers : t -> int list
List, in order, the page reference numbers of a PDF's page tree.
val objnumbers : t -> int list
List the object numbers in a PDF.
val recurse_dict : (pdfobject -> pdfobject) ->
(string * pdfobject) list -> pdfobject
Use the given function on each element of a PDF dictionary.
val recurse_array : (pdfobject -> pdfobject) -> pdfobject list -> pdfobject
Similarly for an Array
. The function is applied to each element.
val changes : t -> (int, int) Stdlib.Hashtbl.t
Calculate the changes required to renumber a PDF's objects 1..n.
val renumber : (int, int) Stdlib.Hashtbl.t -> t -> t
Perform the given renumberings on a PDF.
val renumber_object_parsed : t -> (int, int) Stdlib.Hashtbl.t -> pdfobject -> pdfobject
Renumber an object given a change table.
val bigarray_of_stream : pdfobject -> Pdfio.bytes
Fetch a stream, if necessary, and return its contents (with no processing).
val objects_of_list : (int -> pdfobject) option ->
(int * (objectdata Stdlib.ref * int)) list -> pdfobjects
Make a objects entry from a parser and a list of (number, object) pairs.
val objects_referenced : string list ->
(string * pdfobject) list -> t -> pdfobject -> int list
Calling objects_referenced no_follow_entries no_follow_contains pdf
pdfobject
find the objects reachable from the given object. Dictionary
keys in no_follow_entries
are not explored. Dictionaries containing
entries in no_follow_contains
are not explored.
val generate_id : t -> string -> (unit -> float) -> pdfobject
Generate and ID for a PDF document given its prospective file name (and using the current date and time). If the file name is blank, the ID is still likely to be unique, being based on date and time only. If environment variable CAMLPDF_REPRODUCIBLE_IDS=true is set, the ID will instead be set to a standard value.
val catalog_of_pdf : t -> pdfobject
Return the document catalog.
val find_indirect : string -> pdfobject -> int option
Find the indirect reference given by the value associated with a key in a dictionary.
val nametree_lookup : t -> pdfobject -> pdfobject -> pdfobject option
Calling nametree_lookup pdf k dict
looks up the name in the document's
name tree
val contents_of_nametree : t -> pdfobject -> (pdfobject * pdfobject) list
Return an ordered list of the key-value pairs in a given name tree.
val deep_copy : t -> t
Copy a PDF data structure so that nothing is shared with the original.
val change_id : t -> string -> unit
Change the /ID string in a PDF's trailer dicfionary