[ViewVC] Diff of: cvs/CBOR-XS/XS.pm

Comparing CBOR-XS/XS.pm (file contents):
Revision 1.10 by root, Mon Oct 28 22:03:20 2013 UTC vs.
Revision 1.22 by root, Fri Nov 22 15:28:38 2013 UTC

…		…
26	substr $many_cbor_strings, 0, $length, ""; # remove decoded cbor string	26	substr $many_cbor_strings, 0, $length, ""; # remove decoded cbor string
27	}	27	}
28		28
29	=head1 DESCRIPTION	29	=head1 DESCRIPTION
30		30
31	WARNING! This module is very new, and not very well tested (that's up to	31	WARNING! This module is very new, and not very well tested (that's up
32	you to do). Furthermore, details of the implementation might change freely	32	to you to do). Furthermore, details of the implementation might change
33	before version 1.0. And lastly, the object serialisation protocol depends	33	freely before version 1.0. And lastly, most extensions depend on an IANA
34	on a pending IANA assignment, and until that assignment is official, this	34	assignment, and until that assignment is official, this implementation is
35	implementation is not interoperable with other implementations (even	35	not interoperable with other implementations (even future versions of this
36	future versions of this module) until the assignment is done.	36	module) until the assignment is done.
37		37
38	You are still invited to try out CBOR, and this module.	38	You are still invited to try out CBOR, and this module.
39		39
40	This module converts Perl data structures to the Concise Binary Object	40	This module converts Perl data structures to the Concise Binary Object
41	Representation (CBOR) and vice versa. CBOR is a fast binary serialisation	41	Representation (CBOR) and vice versa. CBOR is a fast binary serialisation
…		…
46	In short, CBOR is a faster and very compact binary alternative to JSON,	46	In short, CBOR is a faster and very compact binary alternative to JSON,
47	with the added ability of supporting serialisation of Perl objects. (JSON	47	with the added ability of supporting serialisation of Perl objects. (JSON
48	often compresses better than CBOR though, so if you plan to compress the	48	often compresses better than CBOR though, so if you plan to compress the
49	data later you might want to compare both formats first).	49	data later you might want to compare both formats first).
50		50
		51	To give you a general idea about speed, with texts in the megabyte range,
		52	C<CBOR::XS> usually encodes roughly twice as fast as L<Storable> or
		53	L<JSON::XS> and decodes about 15%-30% faster than those. The shorter the
		54	data, the worse L<Storable> performs in comparison.
		55
		56	As for compactness, C<CBOR::XS> encoded data structures are usually about
		57	20% smaller than the same data encoded as (compact) JSON or L<Storable>.
		58
		59	In addition to the core CBOR data format, this module implements a number
		60	of extensions, to support cyclic and self-referencing data structures
		61	(see C<allow_sharing>), string deduplication (see C<allow_stringref>) and
		62	scalar references (always enabled).
		63
51	The primary goal of this module is to be I<correct> and the secondary goal	64	The primary goal of this module is to be I<correct> and the secondary goal
52	is to be I<fast>. To reach the latter goal it was written in C.	65	is to be I<fast>. To reach the latter goal it was written in C.
53		66
54	See MAPPING, below, on how CBOR::XS maps perl values to CBOR values and	67	See MAPPING, below, on how CBOR::XS maps perl values to CBOR values and
55	vice versa.	68	vice versa.
…		…
58		71
59	package CBOR::XS;	72	package CBOR::XS;
60		73
61	use common::sense;	74	use common::sense;
62		75
63	our $VERSION = 0.05;	76	our $VERSION = 0.08;
64	our @ISA = qw(Exporter);	77	our @ISA = qw(Exporter);
65		78
66	our @EXPORT = qw(encode_cbor decode_cbor);	79	our @EXPORT = qw(encode_cbor decode_cbor);
67		80
68	use Exporter;	81	use Exporter;
…		…
149	If no argument is given, the limit check will be deactivated (same as when	162	If no argument is given, the limit check will be deactivated (same as when
150	C<0> is specified).	163	C<0> is specified).
151		164
152	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	165	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
153		166
		167	=item $cbor = $cbor->allow_unknown ([$enable])
		168
		169	=item $enabled = $cbor->get_allow_unknown
		170
		171	If C<$enable> is true (or missing), then C<encode> will I<not> throw an
		172	exception when it encounters values it cannot represent in CBOR (for
		173	example, filehandles) but instead will encode a CBOR C<error> value.
		174
		175	If C<$enable> is false (the default), then C<encode> will throw an
		176	exception when it encounters anything it cannot encode as CBOR.
		177
		178	This option does not affect C<decode> in any way, and it is recommended to
		179	leave it off unless you know your communications partner.
		180
		181	=item $cbor = $cbor->allow_sharing ([$enable])
		182
		183	=item $enabled = $cbor->get_allow_sharing
		184
		185	If C<$enable> is true (or missing), then C<encode> will not double-encode
		186	values that have been referenced before (e.g. when the same object, such
		187	as an array, is referenced multiple times), but instead will emit a
		188	reference to the earlier value.
		189
		190	This means that such values will only be encoded once, and will not result
		191	in a deep cloning of the value on decode, in decoders supporting the value
		192	sharing extension.
		193
		194	It is recommended to leave it off unless you know your
		195	communication partner supports the value sharing extensions to CBOR
		196	(http://cbor.schmorp.de/value-sharing).
		197
		198	Detecting shared values incurs a runtime overhead when values are encoded
		199	that have a reference counter large than one, and might unnecessarily
		200	increase the encoded size, as potentially shared values are encode as
		201	sharable whether or not they are actually shared.
		202
		203	At the moment, only targets of references can be shared (e.g. scalars,
		204	arrays or hashes pointed to by a reference). Weirder constructs, such as
		205	an array with multiple "copies" of the I<same> string, which are hard but
		206	not impossible to create in Perl, are not supported (this is the same as
		207	for L<Storable>).
		208
		209	If C<$enable> is false (the default), then C<encode> will encode
		210	exception when it encounters anything it cannot encode as CBOR.
		211
		212	This option does not affect C<decode> in any way - shared values and
		213	references will always be decoded properly if present.
		214
		215	=item $cbor = $cbor->allow_stringref ([$enable])
		216
		217	=item $enabled = $cbor->get_allow_stringref
		218
		219	If C<$enable> is true (or missing), then C<encode> will try not to encode
		220	the same string twice, but will instead encode a reference to the string
		221	instead. Depending on your data format. this can save a lot of space, but
		222	also results in a very large runtime overhead (expect encoding times to be
		223	2-4 times as high as without).
		224
		225	It is recommended to leave it off unless you know your
		226	communications partner supports the stringref extension to CBOR
		227	(http://cbor.schmorp.de/stringref).
		228
		229	If C<$enable> is false (the default), then C<encode> will encode
		230	exception when it encounters anything it cannot encode as CBOR.
		231
		232	This option does not affect C<decode> in any way - string references will
		233	always be decoded properly if present.
		234
154	=item $cbor_data = $cbor->encode ($perl_scalar)	235	=item $cbor_data = $cbor->encode ($perl_scalar)
155		236
156	Converts the given Perl data structure (a scalar value) to its CBOR	237	Converts the given Perl data structure (a scalar value) to its CBOR
157	representation.	238	representation.
158		239
…		…
229	error). See the L<Types::Serialiser> manpage for details.	310	error). See the L<Types::Serialiser> manpage for details.
230		311
231	=item CBOR tag 256 (perl object)	312	=item CBOR tag 256 (perl object)
232		313
233	The tag value C<256> (TODO: pending iana registration) will be used	314	The tag value C<256> (TODO: pending iana registration) will be used
234	to deserialise a Perl object serialised with C<FREEZE>. See "OBJECT	315	to deserialise a Perl object serialised with C<FREEZE>. See L<OBJECT
235	SERIALISATION", below, for details.	316	SERIALISATION>, below, for details.
236		317
237	=item CBOR tag 55799 (magic header)	318	=item CBOR tag 55799 (magic header)
238		319
239	The tag 55799 is ignored (this tag implements the magic header).	320	The tag 55799 is ignored (this tag implements the magic header).
240		321
…		…
283	C<1>, which get turned into false and true in CBOR.	364	C<1>, which get turned into false and true in CBOR.
284		365
285	=item CBOR::XS::Tagged objects	366	=item CBOR::XS::Tagged objects
286		367
287	Objects of this type must be arrays consisting of a single C<[tag, value]>	368	Objects of this type must be arrays consisting of a single C<[tag, value]>
288	pair. The (numerical) tag will be encoded as a CBOR tag, the value will be	369	pair. The (numerical) tag will be encoded as a CBOR tag, the value will
289	encoded as appropriate for the value.	370	be encoded as appropriate for the value. You cna use C<CBOR::XS::tag> to
		371	create such objects.
290		372
291	=item Types::Serialiser::true, Types::Serialiser::false, Types::Serialiser::error	373	=item Types::Serialiser::true, Types::Serialiser::false, Types::Serialiser::error
292		374
293	These special values become CBOR true, CBOR false and CBOR undefined	375	These special values become CBOR true, CBOR false and CBOR undefined
294	values, respectively. You can also use C<\1>, C<\0> and C<\undef> directly	376	values, respectively. You can also use C<\1>, C<\0> and C<\undef> directly
295	if you want.	377	if you want.
296		378
297	=item other blessed objects	379	=item other blessed objects
298		380
299	Other blessed objects are serialised via C<TO_CBOR> or C<FREEZE>. See	381	Other blessed objects are serialised via C<TO_CBOR> or C<FREEZE>. See
300	"OBJECT SERIALISATION", below, for details.	382	L<OBJECT SERIALISATION>, below, for details.
301		383
302	=item simple scalars	384	=item simple scalars
303		385
304	TODO	386	TODO
305	Simple Perl scalars (any scalar that is not a reference) are the most	387	Simple Perl scalars (any scalar that is not a reference) are the most
…		…
446	=head1 MAGIC HEADER	528	=head1 MAGIC HEADER
447		529
448	There is no way to distinguish CBOR from other formats	530	There is no way to distinguish CBOR from other formats
449	programmatically. To make it easier to distinguish CBOR from other	531	programmatically. To make it easier to distinguish CBOR from other
450	formats, the CBOR specification has a special "magic string" that can be	532	formats, the CBOR specification has a special "magic string" that can be
451	prepended to any CBOR string without changing it's meaning.	533	prepended to any CBOR string without changing its meaning.
452		534
453	This string is available as C<$CBOR::XS::MAGIC>. This module does not	535	This string is available as C<$CBOR::XS::MAGIC>. This module does not
454	prepend this string tot he CBOR data it generates, but it will ignroe it	536	prepend this string to the CBOR data it generates, but it will ignore it
455	if present, so users can prepend this string as a "file type" indicator as	537	if present, so users can prepend this string as a "file type" indicator as
456	required.	538	required.
		539
		540
		541	=head1 THE CBOR::XS::Tagged CLASS
		542
		543	CBOR has the concept of tagged values - any CBOR value can be tagged with
		544	a numeric 64 bit number, which are centrally administered.
		545
		546	C<CBOR::XS> handles a few tags internally when en- or decoding. You can
		547	also create tags yourself by encoding C<CBOR::XS::Tagged> objects, and the
		548	decoder will create C<CBOR::XS::Tagged> objects itself when it hits an
		549	unknown tag.
		550
		551	These objects are simply blessed array references - the first member of
		552	the array being the numerical tag, the second being the value.
		553
		554	You can interact with C<CBOR::XS::Tagged> objects in the following ways:
		555
		556	=over 4
		557
		558	=item $tagged = CBOR::XS::tag $tag, $value
		559
		560	This function(!) creates a new C<CBOR::XS::Tagged> object using the given
		561	C<$tag> (0..2**64-1) to tag the given C<$value> (which can be any Perl
		562	value that can be encoded in CBOR, including serialisable Perl objects and
		563	C<CBOR::XS::Tagged> objects).
		564
		565	=item $tagged->[0]
		566
		567	=item $tagged->[0] = $new_tag
		568
		569	=item $tag = $tagged->tag
		570
		571	=item $new_tag = $tagged->tag ($new_tag)
		572
		573	Access/mutate the tag.
		574
		575	=item $tagged->[1]
		576
		577	=item $tagged->[1] = $new_value
		578
		579	=item $value = $tagged->value
		580
		581	=item $new_value = $tagged->value ($new_value)
		582
		583	Access/mutate the tagged value.
		584
		585	=back
		586
		587	=cut
		588
		589	sub tag($$) {
		590	bless [@_], CBOR::XS::Tagged::;
		591	}
		592
		593	sub CBOR::XS::Tagged::tag {
		594	$_[0][0] = $_[1] if $#_;
		595	$_[0][0]
		596	}
		597
		598	sub CBOR::XS::Tagged::value {
		599	$_[0][1] = $_[1] if $#_;
		600	$_[0][1]
		601	}
		602
		603	=head2 EXAMPLES
		604
		605	Here are some examples of C<CBOR::XS::Tagged> uses to tag objects.
		606
		607	You can look up CBOR tag value and emanings in the IANA registry at
		608	L<http://www.iana.org/assignments/cbor-tags/cbor-tags.xhtml>.
		609
		610	Prepend a magic header (C<$CBOR::XS::MAGIC>):
		611
		612	my $cbor = encode_cbor CBOR::XS::tag 55799, $value;
		613	# same as:
		614	my $cbor = $CBOR::XS::MAGIC . encode_cbor $value;
		615
		616	Serialise some URIs and a regex in an array:
		617
		618	my $cbor = encode_cbor [
		619	(CBOR::XS::tag 32, "http://www.nethype.de/"),
		620	(CBOR::XS::tag 32, "http://software.schmorp.de/"),
		621	(CBOR::XS::tag 35, "^[Pp][Ee][Rr][lL]\$"),
		622	];
		623
		624	Wrap CBOR data in CBOR:
		625
		626	my $cbor_cbor = encode_cbor
		627	CBOR::XS::tag 24,
		628	encode_cbor [1, 2, 3];
		629
		630	=head1 TAG HANDLING AND EXTENSIONS
		631
		632	This section describes how this module handles specific tagged values
		633	and extensions. If a tag is not mentioned here and no additional filters
		634	are provided for it, then the default handling applies (creating a
		635	CBOR::XS::Tagged object on decoding, and only encoding the tag when
		636	explicitly requested).
		637
		638	Future versions of this module reserve the right to special case
		639	additional tags (such as base64url).
		640
		641	=head2 ENFORCED TAGS
		642
		643	These tags are always handled when decoding, and their handling cannot be
		644	overriden by the user.
		645
		646	=over 4
		647
		648	=item <unassigned> (perl-object, L<http://cbor.schmorp.de/perl-object>)
		649
		650	These tags are automatically created for serialisable objects using the
		651	C<FREEZE/THAW> methods (the L<Types::Serialier> object serialisation
		652	protocol).
		653
		654	=item <unassigned>, <unassigned> (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>)
		655
		656	These tags are automatically decoded when encountered, resulting in
		657	shared values in the decoded object. They are only encoded, however, when
		658	C<allow_sharable> is enabled.
		659
		660	=item <unassigned>, <unassigned> (stringref-namespace, stringref, L <http://cbor.schmorp.de/stringref>)
		661
		662	These tags are automatically decoded when encountered. They are only
		663	encoded, however, when C<allow_stringref> is enabled.
		664
		665	=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>)
		666
		667	This tag is automatically generated when a reference are encountered (with
		668	the exception of hash and array refernces). It is converted to a reference
		669	when decoding.
		670
		671	=item 55799 (self-describe CBOR, RFC 7049)
		672
		673	This value is not generated on encoding (unless explicitly requested by
		674	the user), and is simply ignored when decoding.
		675
		676	=back
		677
		678	=head2 OPTIONAL TAGS
		679
		680	These tags have default filters provided when decoding. Their handling can
		681	be overriden by changing the C<%CBOR::XS::FILTER> entry for the tag, or by
		682	providing a custom C<filter> function when decoding.
		683
		684	When they result in decoding into a specific Perl class, the module
		685	usually provides a corresponding C<TO_CBOR> method as well.
		686
		687	When any of these need to load additional modules that are not part of the
		688	perl core distribution (e.g. L<URI>), it is (currently) up to the user to
		689	provide these modules. The decoding usually fails with an exception if the
		690	required module cannot be loaded.
		691
		692	=over 4
		693
		694	=item 2, 3 (positive/negative bignum)
		695
		696	These tags are decoded into L<Math::BigInt> objects. The corresponding
		697	C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR
		698	integers, and others into positive/negative CBOR bignums.
		699
		700	=item 4, 5 (decimal fraction/bigfloat)
		701
		702	Both decimal fractions and bigfloats are decoded into L<Math::BigFloat>
		703	objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always>
		704	encodes into a decimal fraction.
		705
		706	CBOR cannot represent bigfloats with I<very> large exponents - conversion
		707	of such big float objects is undefined.
		708
		709	Also, NaN and infinities are not encoded properly.
		710
		711	=item 21, 22, 23 (expected later JSON conversion)
		712
		713	CBOR::XS is not a CBOR-to-JSON converter, and will simply ignore these
		714	tags.
		715
		716	=item 32 (URI)
		717
		718	These objects decode into L<URI> objects. The corresponding
		719	C<URI::TO_CBOR> method again results in a CBOR URI value.
		720
		721	=back
		722
		723	=cut
		724
		725	our %FILTER = (
		726	# 0 # rfc4287 datetime, utf-8
		727	# 1 # unix timestamp, any
		728
		729	2 => sub { # pos bigint
		730	require Math::BigInt;
		731	Math::BigInt->new ("0x" . unpack "H*", pop)
		732	},
		733
		734	3 => sub { # neg bigint
		735	require Math::BigInt;
		736	-Math::BigInt->new ("0x" . unpack "H*", pop)
		737	},
		738
		739	4 => sub { # decimal fraction, array
		740	require Math::BigFloat;
		741	Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
		742	},
		743
		744	5 => sub { # bigfloat, array
		745	require Math::BigFloat;
		746	scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2)
		747	},
		748
		749	21 => sub { pop }, # expected conversion to base64url encoding
		750	22 => sub { pop }, # expected conversion to base64 encoding
		751	23 => sub { pop }, # expected conversion to base16 encoding
		752
		753	# 24 # embedded cbor, byte string
		754
		755	32 => sub {
		756	require URI;
		757	URI->new (pop)
		758	},
		759
		760	# 33 # base64url rfc4648, utf-8
		761	# 34 # base64 rfc46484, utf-8
		762	# 35 # regex pcre/ecma262, utf-8
		763	# 36 # mime message rfc2045, utf-8
		764	);
457		765
458		766
459	=head1 CBOR and JSON	767	=head1 CBOR and JSON
460		768
461	CBOR is supposed to implement a superset of the JSON data model, and is,	769	CBOR is supposed to implement a superset of the JSON data model, and is,
…		…
544	Please refrain from using rt.cpan.org or any other bug reporting	852	Please refrain from using rt.cpan.org or any other bug reporting
545	service. I put the contact address into my modules for a reason.	853	service. I put the contact address into my modules for a reason.
546		854
547	=cut	855	=cut
548		856
		857	our %FILTER = (
		858	# 0 # rfc4287 datetime, utf-8
		859	# 1 # unix timestamp, any
		860
		861	2 => sub { # pos bigint
		862	require Math::BigInt;
		863	Math::BigInt->new ("0x" . unpack "H*", pop)
		864	},
		865
		866	3 => sub { # neg bigint
		867	require Math::BigInt;
		868	-Math::BigInt->new ("0x" . unpack "H*", pop)
		869	},
		870
		871	4 => sub { # decimal fraction, array
		872	require Math::BigFloat;
		873	Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
		874	},
		875
		876	5 => sub { # bigfloat, array
		877	require Math::BigFloat;
		878	scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2)
		879	},
		880
		881	21 => sub { pop }, # expected conversion to base64url encoding
		882	22 => sub { pop }, # expected conversion to base64 encoding
		883	23 => sub { pop }, # expected conversion to base16 encoding
		884
		885	# 24 # embedded cbor, byte string
		886
		887	32 => sub {
		888	require URI;
		889	URI->new (pop)
		890	},
		891
		892	# 33 # base64url rfc4648, utf-8
		893	# 34 # base64 rfc46484, utf-8
		894	# 35 # regex pcre/ecma262, utf-8
		895	# 36 # mime message rfc2045, utf-8
		896	);
		897
		898	sub CBOR::XS::default_filter {
		899	&{ $FILTER{$_[0]} or return }
		900	}
		901
		902	sub URI::TO_CBOR {
		903	my $uri = $_[0]->as_string;
		904	utf8::upgrade $uri;
		905	CBOR::XS::tag 32, $uri
		906	}
		907
		908	sub Math::BigInt::TO_CBOR {
		909	if ($_[0] >= -2147483648 && $_[0] <= 2147483647) {
		910	$_[0]->numify
		911	} else {
		912	my $hex = substr $_[0]->as_hex, 2;
		913	$hex = "0$hex" if 1 & length $hex; # sigh
		914	CBOR::XS::tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex
		915	}
		916	}
		917
		918	sub Math::BigFloat::TO_CBOR {
		919	my ($m, $e) = $_[0]->parts;
		920	CBOR::XS::tag 4, [$e->numify, $m]
		921	}
		922
549	XSLoader::load "CBOR::XS", $VERSION;	923	XSLoader::load "CBOR::XS", $VERSION;
550		924
551	=head1 SEE ALSO	925	=head1 SEE ALSO
552		926
553	The L<JSON> and L<JSON::XS> modules that do similar, but human-readable,	927	The L<JSON> and L<JSON::XS> modules that do similar, but human-readable,

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Comparing CBOR-XS/XS.pm (file contents): Revision 1.10 by root, Mon Oct 28 22:03:20 2013 UTC vs. Revision 1.22 by root, Fri Nov 22 15:28:38 2013 UTC

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Comparing CBOR-XS/XS.pm (file contents):
Revision 1.10 by root, Mon Oct 28 22:03:20 2013 UTC vs.
Revision 1.22 by root, Fri Nov 22 15:28:38 2013 UTC