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

Comparing CBOR-XS/XS.pm (file contents):
Revision 1.17 by root, Wed Oct 30 10:11:04 2013 UTC vs.
Revision 1.23 by root, Fri Nov 22 16:00:30 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
…		…
54	data, the worse L<Storable> performs in comparison.	54	data, the worse L<Storable> performs in comparison.
55		55
56	As for compactness, C<CBOR::XS> encoded data structures are usually about	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>.	57	20% smaller than the same data encoded as (compact) JSON or L<Storable>.
58		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
59	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
60	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.
61		66
62	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
63	vice versa.	68	vice versa.
…		…
113	strings. All boolean flags described below are by default I<disabled>.	118	strings. All boolean flags described below are by default I<disabled>.
114		119
115	The mutators for flags all return the CBOR object again and thus calls can	120	The mutators for flags all return the CBOR object again and thus calls can
116	be chained:	121	be chained:
117		122
118	#TODO
119	my $cbor = CBOR::XS->new->encode ({a => [1,2]});	123	my $cbor = CBOR::XS->new->encode ({a => [1,2]});
120		124
121	=item $cbor = $cbor->max_depth ([$maximum_nesting_depth])	125	=item $cbor = $cbor->max_depth ([$maximum_nesting_depth])
122		126
123	=item $max_depth = $cbor->get_max_depth	127	=item $max_depth = $cbor->get_max_depth
…		…
157	If no argument is given, the limit check will be deactivated (same as when	161	If no argument is given, the limit check will be deactivated (same as when
158	C<0> is specified).	162	C<0> is specified).
159		163
160	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	164	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
161		165
		166	=item $cbor = $cbor->allow_unknown ([$enable])
		167
		168	=item $enabled = $cbor->get_allow_unknown
		169
		170	If C<$enable> is true (or missing), then C<encode> will I<not> throw an
		171	exception when it encounters values it cannot represent in CBOR (for
		172	example, filehandles) but instead will encode a CBOR C<error> value.
		173
		174	If C<$enable> is false (the default), then C<encode> will throw an
		175	exception when it encounters anything it cannot encode as CBOR.
		176
		177	This option does not affect C<decode> in any way, and it is recommended to
		178	leave it off unless you know your communications partner.
		179
		180	=item $cbor = $cbor->allow_sharing ([$enable])
		181
		182	=item $enabled = $cbor->get_allow_sharing
		183
		184	If C<$enable> is true (or missing), then C<encode> will not double-encode
		185	values that have been referenced before (e.g. when the same object, such
		186	as an array, is referenced multiple times), but instead will emit a
		187	reference to the earlier value.
		188
		189	This means that such values will only be encoded once, and will not result
		190	in a deep cloning of the value on decode, in decoders supporting the value
		191	sharing extension.
		192
		193	It is recommended to leave it off unless you know your
		194	communication partner supports the value sharing extensions to CBOR
		195	(http://cbor.schmorp.de/value-sharing).
		196
		197	Detecting shared values incurs a runtime overhead when values are encoded
		198	that have a reference counter large than one, and might unnecessarily
		199	increase the encoded size, as potentially shared values are encode as
		200	sharable whether or not they are actually shared.
		201
		202	At the moment, only targets of references can be shared (e.g. scalars,
		203	arrays or hashes pointed to by a reference). Weirder constructs, such as
		204	an array with multiple "copies" of the I<same> string, which are hard but
		205	not impossible to create in Perl, are not supported (this is the same as
		206	for L<Storable>).
		207
		208	If C<$enable> is false (the default), then C<encode> will encode
		209	exception when it encounters anything it cannot encode as CBOR.
		210
		211	This option does not affect C<decode> in any way - shared values and
		212	references will always be decoded properly if present.
		213
		214	=item $cbor = $cbor->allow_stringref ([$enable])
		215
		216	=item $enabled = $cbor->get_allow_stringref
		217
		218	If C<$enable> is true (or missing), then C<encode> will try not to encode
		219	the same string twice, but will instead encode a reference to the string
		220	instead. Depending on your data format. this can save a lot of space, but
		221	also results in a very large runtime overhead (expect encoding times to be
		222	2-4 times as high as without).
		223
		224	It is recommended to leave it off unless you know your
		225	communications partner supports the stringref extension to CBOR
		226	(http://cbor.schmorp.de/stringref).
		227
		228	If C<$enable> is false (the default), then C<encode> will encode
		229	exception when it encounters anything it cannot encode as CBOR.
		230
		231	This option does not affect C<decode> in any way - string references will
		232	always be decoded properly if present.
		233
		234	=item $cbor = $cbor->filter ([$cb->($tag, $value)])
		235
		236	=item $cb_or_undef = $cbor->get_filter
		237
		238	TODO
		239
162	=item $cbor_data = $cbor->encode ($perl_scalar)	240	=item $cbor_data = $cbor->encode ($perl_scalar)
163		241
164	Converts the given Perl data structure (a scalar value) to its CBOR	242	Converts the given Perl data structure (a scalar value) to its CBOR
165	representation.	243	representation.
166		244
…		…
234	C<Types:Serialiser::false> and C<Types::Serialiser::error>,	312	C<Types:Serialiser::false> and C<Types::Serialiser::error>,
235	respectively. They are overloaded to act almost exactly like the numbers	313	respectively. They are overloaded to act almost exactly like the numbers
236	C<1> and C<0> (for true and false) or to throw an exception on access (for	314	C<1> and C<0> (for true and false) or to throw an exception on access (for
237	error). See the L<Types::Serialiser> manpage for details.	315	error). See the L<Types::Serialiser> manpage for details.
238		316
239	=item CBOR tag 256 (perl object)	317	=item tagged values
240		318
241	The tag value C<256> (TODO: pending iana registration) will be used
242	to deserialise a Perl object serialised with C<FREEZE>. See L<OBJECT
243	SERIALISATION>, below, for details.
244
245	=item CBOR tag 55799 (magic header)
246
247	The tag 55799 is ignored (this tag implements the magic header).
248
249	=item other CBOR tags
250
251	Tagged items consists of a numeric tag and another CBOR value. Tags not	319	Tagged items consists of a numeric tag and another CBOR value.
252	handled internally are currently converted into a L<CBOR::XS::Tagged>
253	object, which is simply a blessed array reference consisting of the
254	numeric tag value followed by the (decoded) CBOR value.
255		320
256	In the future, support for user-supplied conversions might get added.	321	See L<TAG HANDLING AND EXTENSIONS> and the description of C<< ->filter >>
		322	for details.
257		323
258	=item anything else	324	=item anything else
259		325
260	Anything else (e.g. unsupported simple values) will raise a decoding	326	Anything else (e.g. unsupported simple values) will raise a decoding
261	error.	327	error.
…		…
304	if you want.	370	if you want.
305		371
306	=item other blessed objects	372	=item other blessed objects
307		373
308	Other blessed objects are serialised via C<TO_CBOR> or C<FREEZE>. See	374	Other blessed objects are serialised via C<TO_CBOR> or C<FREEZE>. See
309	L<OBJECT SERIALISATION>, below, for details.	375	L<TAG HANDLING AND EXTENSIONS> for specific classes handled by this
		376	module, and L<OBJECT SERIALISATION> for generic object serialisation.
310		377
311	=item simple scalars	378	=item simple scalars
312		379
313	TODO
314	Simple Perl scalars (any scalar that is not a reference) are the most	380	Simple Perl scalars (any scalar that is not a reference) are the most
315	difficult objects to encode: CBOR::XS will encode undefined scalars as	381	difficult objects to encode: CBOR::XS will encode undefined scalars as
316	CBOR null values, scalars that have last been used in a string context	382	CBOR null values, scalars that have last been used in a string context
317	before encoding as CBOR strings, and anything else as number value:	383	before encoding as CBOR strings, and anything else as number value:
318		384
…		…
455	=head1 MAGIC HEADER	521	=head1 MAGIC HEADER
456		522
457	There is no way to distinguish CBOR from other formats	523	There is no way to distinguish CBOR from other formats
458	programmatically. To make it easier to distinguish CBOR from other	524	programmatically. To make it easier to distinguish CBOR from other
459	formats, the CBOR specification has a special "magic string" that can be	525	formats, the CBOR specification has a special "magic string" that can be
460	prepended to any CBOR string without changing it's meaning.	526	prepended to any CBOR string without changing its meaning.
461		527
462	This string is available as C<$CBOR::XS::MAGIC>. This module does not	528	This string is available as C<$CBOR::XS::MAGIC>. This module does not
463	prepend this string tot he CBOR data it generates, but it will ignroe it	529	prepend this string to the CBOR data it generates, but it will ignore it
464	if present, so users can prepend this string as a "file type" indicator as	530	if present, so users can prepend this string as a "file type" indicator as
465	required.	531	required.
466		532
467		533
468	=head1 THE CBOR::XS::Tagged CLASS	534	=head1 THE CBOR::XS::Tagged CLASS
…		…
551	Wrap CBOR data in CBOR:	617	Wrap CBOR data in CBOR:
552		618
553	my $cbor_cbor = encode_cbor	619	my $cbor_cbor = encode_cbor
554	CBOR::XS::tag 24,	620	CBOR::XS::tag 24,
555	encode_cbor [1, 2, 3];	621	encode_cbor [1, 2, 3];
		622
		623	=head1 TAG HANDLING AND EXTENSIONS
		624
		625	This section describes how this module handles specific tagged values
		626	and extensions. If a tag is not mentioned here and no additional filters
		627	are provided for it, then the default handling applies (creating a
		628	CBOR::XS::Tagged object on decoding, and only encoding the tag when
		629	explicitly requested).
		630
		631	Tags not handled specifically are currently converted into a
		632	L<CBOR::XS::Tagged> object, which is simply a blessed array reference
		633	consisting of the numeric tag value followed by the (decoded) CBOR value.
		634
		635	Future versions of this module reserve the right to special case
		636	additional tags (such as base64url).
		637
		638	=head2 ENFORCED TAGS
		639
		640	These tags are always handled when decoding, and their handling cannot be
		641	overriden by the user.
		642
		643	=over 4
		644
		645	=item <unassigned> (perl-object, L<http://cbor.schmorp.de/perl-object>)
		646
		647	These tags are automatically created (and decoded) for serialisable
		648	objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object
		649	serialisation protocol). See L<OBJECT SERIALISATION> for details.
		650
		651	=item <unassigned>, <unassigned> (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>)
		652
		653	These tags are automatically decoded when encountered, resulting in
		654	shared values in the decoded object. They are only encoded, however, when
		655	C<allow_sharable> is enabled.
		656
		657	=item <unassigned>, <unassigned> (stringref-namespace, stringref, L <http://cbor.schmorp.de/stringref>)
		658
		659	These tags are automatically decoded when encountered. They are only
		660	encoded, however, when C<allow_stringref> is enabled.
		661
		662	=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>)
		663
		664	This tag is automatically generated when a reference are encountered (with
		665	the exception of hash and array refernces). It is converted to a reference
		666	when decoding.
		667
		668	=item 55799 (self-describe CBOR, RFC 7049)
		669
		670	This value is not generated on encoding (unless explicitly requested by
		671	the user), and is simply ignored when decoding.
		672
		673	=back
		674
		675	=head2 OPTIONAL TAGS
		676
		677	These tags have default filters provided when decoding. Their handling can
		678	be overriden by changing the C<%CBOR::XS::FILTER> entry for the tag, or by
		679	providing a custom C<filter> function when decoding.
		680
		681	When they result in decoding into a specific Perl class, the module
		682	usually provides a corresponding C<TO_CBOR> method as well.
		683
		684	When any of these need to load additional modules that are not part of the
		685	perl core distribution (e.g. L<URI>), it is (currently) up to the user to
		686	provide these modules. The decoding usually fails with an exception if the
		687	required module cannot be loaded.
		688
		689	=over 4
		690
		691	=item 2, 3 (positive/negative bignum)
		692
		693	These tags are decoded into L<Math::BigInt> objects. The corresponding
		694	C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR
		695	integers, and others into positive/negative CBOR bignums.
		696
		697	=item 4, 5 (decimal fraction/bigfloat)
		698
		699	Both decimal fractions and bigfloats are decoded into L<Math::BigFloat>
		700	objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always>
		701	encodes into a decimal fraction.
		702
		703	CBOR cannot represent bigfloats with I<very> large exponents - conversion
		704	of such big float objects is undefined.
		705
		706	Also, NaN and infinities are not encoded properly.
		707
		708	=item 21, 22, 23 (expected later JSON conversion)
		709
		710	CBOR::XS is not a CBOR-to-JSON converter, and will simply ignore these
		711	tags.
		712
		713	=item 32 (URI)
		714
		715	These objects decode into L<URI> objects. The corresponding
		716	C<URI::TO_CBOR> method again results in a CBOR URI value.
		717
		718	=back
		719
		720	=cut
		721
		722	our %FILTER = (
		723	# 0 # rfc4287 datetime, utf-8
		724	# 1 # unix timestamp, any
		725
		726	2 => sub { # pos bigint
		727	require Math::BigInt;
		728	Math::BigInt->new ("0x" . unpack "H*", pop)
		729	},
		730
		731	3 => sub { # neg bigint
		732	require Math::BigInt;
		733	-Math::BigInt->new ("0x" . unpack "H*", pop)
		734	},
		735
		736	4 => sub { # decimal fraction, array
		737	require Math::BigFloat;
		738	Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
		739	},
		740
		741	5 => sub { # bigfloat, array
		742	require Math::BigFloat;
		743	scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2)
		744	},
		745
		746	21 => sub { pop }, # expected conversion to base64url encoding
		747	22 => sub { pop }, # expected conversion to base64 encoding
		748	23 => sub { pop }, # expected conversion to base16 encoding
		749
		750	# 24 # embedded cbor, byte string
		751
		752	32 => sub {
		753	require URI;
		754	URI->new (pop)
		755	},
		756
		757	# 33 # base64url rfc4648, utf-8
		758	# 34 # base64 rfc46484, utf-8
		759	# 35 # regex pcre/ecma262, utf-8
		760	# 36 # mime message rfc2045, utf-8
		761	);
		762
556		763
557	=head1 CBOR and JSON	764	=head1 CBOR and JSON
558		765
559	CBOR is supposed to implement a superset of the JSON data model, and is,	766	CBOR is supposed to implement a superset of the JSON data model, and is,
560	with some coercion, able to represent all JSON texts (something that other	767	with some coercion, able to represent all JSON texts (something that other
…		…
642	Please refrain from using rt.cpan.org or any other bug reporting	849	Please refrain from using rt.cpan.org or any other bug reporting
643	service. I put the contact address into my modules for a reason.	850	service. I put the contact address into my modules for a reason.
644		851
645	=cut	852	=cut
646		853
		854	our %FILTER = (
		855	# 0 # rfc4287 datetime, utf-8
		856	# 1 # unix timestamp, any
		857
		858	2 => sub { # pos bigint
		859	require Math::BigInt;
		860	Math::BigInt->new ("0x" . unpack "H*", pop)
		861	},
		862
		863	3 => sub { # neg bigint
		864	require Math::BigInt;
		865	-Math::BigInt->new ("0x" . unpack "H*", pop)
		866	},
		867
		868	4 => sub { # decimal fraction, array
		869	require Math::BigFloat;
		870	Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
		871	},
		872
		873	5 => sub { # bigfloat, array
		874	require Math::BigFloat;
		875	scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2)
		876	},
		877
		878	21 => sub { pop }, # expected conversion to base64url encoding
		879	22 => sub { pop }, # expected conversion to base64 encoding
		880	23 => sub { pop }, # expected conversion to base16 encoding
		881
		882	# 24 # embedded cbor, byte string
		883
		884	32 => sub {
		885	require URI;
		886	URI->new (pop)
		887	},
		888
		889	# 33 # base64url rfc4648, utf-8
		890	# 34 # base64 rfc46484, utf-8
		891	# 35 # regex pcre/ecma262, utf-8
		892	# 36 # mime message rfc2045, utf-8
		893	);
		894
		895	sub CBOR::XS::default_filter {
		896	&{ $FILTER{$_[0]} or return }
		897	}
		898
		899	sub URI::TO_CBOR {
		900	my $uri = $_[0]->as_string;
		901	utf8::upgrade $uri;
		902	CBOR::XS::tag 32, $uri
		903	}
		904
		905	sub Math::BigInt::TO_CBOR {
		906	if ($_[0] >= -2147483648 && $_[0] <= 2147483647) {
		907	$_[0]->numify
		908	} else {
		909	my $hex = substr $_[0]->as_hex, 2;
		910	$hex = "0$hex" if 1 & length $hex; # sigh
		911	CBOR::XS::tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex
		912	}
		913	}
		914
		915	sub Math::BigFloat::TO_CBOR {
		916	my ($m, $e) = $_[0]->parts;
		917	CBOR::XS::tag 4, [$e->numify, $m]
		918	}
		919
647	XSLoader::load "CBOR::XS", $VERSION;	920	XSLoader::load "CBOR::XS", $VERSION;
648		921
649	=head1 SEE ALSO	922	=head1 SEE ALSO
650		923
651	The L<JSON> and L<JSON::XS> modules that do similar, but human-readable,	924	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 1.17 by root, Wed Oct 30 10:11:04 2013 UTC vs. Revision 1.23 by root, Fri Nov 22 16:00:30 2013 UTC

Diff Legend

Comparing CBOR-XS/XS.pm (file contents):
Revision 1.17 by root, Wed Oct 30 10:11:04 2013 UTC vs.
Revision 1.23 by root, Fri Nov 22 16:00:30 2013 UTC