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

Comparing CBOR-XS/XS.pm (file contents):
Revision 1.21 by root, Wed Nov 20 16:29:02 2013 UTC vs.
Revision 1.26 by root, Thu Nov 28 12:11:06 2013 UTC

…		…
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	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	60	of extensions, to support cyclic and self-referencing data structures
61	(see C<allow_sharing>), string deduplication (see C<allow_stringref>) and	61	(see C<allow_sharing>), string deduplication (see C<pack_strings>) and
62	scalar references (always enabled).	62	scalar references (always enabled).
63		63
64	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
65	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.
66		66
…		…
71		71
72	package CBOR::XS;	72	package CBOR::XS;
73		73
74	use common::sense;	74	use common::sense;
75		75
76	our $VERSION = 0.08;	76	our $VERSION = 0.09;
77	our @ISA = qw(Exporter);	77	our @ISA = qw(Exporter);
78		78
79	our @EXPORT = qw(encode_cbor decode_cbor);	79	our @EXPORT = qw(encode_cbor decode_cbor);
80		80
81	use Exporter;	81	use Exporter;
…		…
118	strings. All boolean flags described below are by default I<disabled>.	118	strings. All boolean flags described below are by default I<disabled>.
119		119
120	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
121	be chained:	121	be chained:
122		122
123	#TODO
124	my $cbor = CBOR::XS->new->encode ({a => [1,2]});	123	my $cbor = CBOR::XS->new->encode ({a => [1,2]});
125		124
126	=item $cbor = $cbor->max_depth ([$maximum_nesting_depth])	125	=item $cbor = $cbor->max_depth ([$maximum_nesting_depth])
127		126
128	=item $max_depth = $cbor->get_max_depth	127	=item $max_depth = $cbor->get_max_depth
…		…
187	as an array, is referenced multiple times), but instead will emit a	186	as an array, is referenced multiple times), but instead will emit a
188	reference to the earlier value.	187	reference to the earlier value.
189		188
190	This means that such values will only be encoded once, and will not result	189	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	190	in a deep cloning of the value on decode, in decoders supporting the value
192	sharing extension.	191	sharing extension. This also makes it possible to encode cyclic data
		192	structures.
193		193
194	It is recommended to leave it off unless you know your	194	It is recommended to leave it off unless you know your
195	communication partner supports the value sharing extensions to CBOR	195	communication partner supports the value sharing extensions to CBOR
196	(http://cbor.schmorp.de/value-sharing).	196	(L<http://cbor.schmorp.de/value-sharing>), as without decoder support, the
		197	resulting data structure might be unusable.
197		198
198	Detecting shared values incurs a runtime overhead when values are encoded	199	Detecting shared values incurs a runtime overhead when values are encoded
199	that have a reference counter large than one, and might unnecessarily	200	that have a reference counter large than one, and might unnecessarily
200	increase the encoded size, as potentially shared values are encode as	201	increase the encoded size, as potentially shared values are encode as
201	sharable whether or not they are actually shared.	202	sharable whether or not they are actually shared.
202		203
203	At the moment, only targets of references can be shared (e.g. scalars,	204	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	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	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	not impossible to create in Perl, are not supported (this is the same as
207	for L<Storable>).	208	with L<Storable>).
208		209
209	If C<$enable> is false (the default), then C<encode> will encode	210	If C<$enable> is false (the default), then C<encode> will encode shared
210	exception when it encounters anything it cannot encode as CBOR.	211	data structures repeatedly, unsharing them in the process. Cyclic data
		212	structures cannot be encoded in this mode.
211		213
212	This option does not affect C<decode> in any way - shared values and	214	This option does not affect C<decode> in any way - shared values and
213	references will always be decoded properly if present.	215	references will always be decoded properly if present.
214		216
215	=item $cbor = $cbor->allow_stringref ([$enable])	217	=item $cbor = $cbor->pack_strings ([$enable])
216		218
217	=item $enabled = $cbor->get_allow_stringref	219	=item $enabled = $cbor->get_pack_strings
218		220
219	If C<$enable> is true (or missing), then C<encode> will try not to encode	221	If C<$enable> is true (or missing), then C<encode> will try not to encode
220	the same string twice, but will instead encode a reference to the string	222	the same string twice, but will instead encode a reference to the string
221	instead. Depending on your data format. this can save a lot of space, but	223	instead. Depending on your data format, this can save a lot of space, but
222	also results in a very large runtime overhead (expect encoding times to be	224	also results in a very large runtime overhead (expect encoding times to be
223	2-4 times as high as without).	225	2-4 times as high as without).
224		226
225	It is recommended to leave it off unless you know your	227	It is recommended to leave it off unless you know your
226	communications partner supports the stringref extension to CBOR	228	communications partner supports the stringref extension to CBOR
227	(http://cbor.schmorp.de/stringref).	229	(L<http://cbor.schmorp.de/stringref>), as without decoder support, the
		230	resulting data structure might not be usable.
228		231
229	If C<$enable> is false (the default), then C<encode> will encode	232	If C<$enable> is false (the default), then C<encode> will encode strings
230	exception when it encounters anything it cannot encode as CBOR.	233	the standard CBOR way.
231		234
232	This option does not affect C<decode> in any way - string references will	235	This option does not affect C<decode> in any way - string references will
233	always be decoded properly if present.	236	always be decoded properly if present.
		237
		238	=item $cbor = $cbor->filter ([$cb->($tag, $value)])
		239
		240	=item $cb_or_undef = $cbor->get_filter
		241
		242	Sets or replaces the tagged value decoding filter (when C<$cb> is
		243	specified) or clears the filter (if no argument or C<undef> is provided).
		244
		245	The filter callback is called only during decoding, when a non-enforced
		246	tagged value has been decoded (see L<TAG HANDLING AND EXTENSIONS> for a
		247	list of enforced tags). For specific tags, it's often better to provide a
		248	default converter using the C<%CBOR::XS::FILTER> hash (see below).
		249
		250	The first argument is the numerical tag, the second is the (decoded) value
		251	that has been tagged.
		252
		253	The filter function should return either exactly one value, which will
		254	replace the tagged value in the decoded data structure, or no values,
		255	which will result in default handling, which currently means the decoder
		256	creates a C<CBOR::XS::Tagged> object to hold the tag and the value.
		257
		258	When the filter is cleared (the default state), the default filter
		259	function, C<CBOR::XS::default_filter>, is used. This function simply looks
		260	up the tag in the C<%CBOR::XS::FILTER> hash. If an entry exists it must be
		261	a code reference that is called with tag and value, and is responsible for
		262	decoding the value. If no entry exists, it returns no values.
		263
		264	Example: decode all tags not handled internally into CBOR::XS::Tagged
		265	objects, with no other special handling (useful when working with
		266	potentially "unsafe" CBOR data).
		267
		268	CBOR::XS->new->filter (sub { })->decode ($cbor_data);
		269
		270	Example: provide a global filter for tag 1347375694, converting the value
		271	into some string form.
		272
		273	$CBOR::XS::FILTER{1347375694} = sub {
		274	my ($tag, $value);
		275
		276	"tag 1347375694 value $value"
		277	};
234		278
235	=item $cbor_data = $cbor->encode ($perl_scalar)	279	=item $cbor_data = $cbor->encode ($perl_scalar)
236		280
237	Converts the given Perl data structure (a scalar value) to its CBOR	281	Converts the given Perl data structure (a scalar value) to its CBOR
238	representation.	282	representation.
…		…
307	C<Types:Serialiser::false> and C<Types::Serialiser::error>,	351	C<Types:Serialiser::false> and C<Types::Serialiser::error>,
308	respectively. They are overloaded to act almost exactly like the numbers	352	respectively. They are overloaded to act almost exactly like the numbers
309	C<1> and C<0> (for true and false) or to throw an exception on access (for	353	C<1> and C<0> (for true and false) or to throw an exception on access (for
310	error). See the L<Types::Serialiser> manpage for details.	354	error). See the L<Types::Serialiser> manpage for details.
311		355
312	=item CBOR tag 256 (perl object)	356	=item tagged values
313		357
314	The tag value C<256> (TODO: pending iana registration) will be used
315	to deserialise a Perl object serialised with C<FREEZE>. See L<OBJECT
316	SERIALISATION>, below, for details.
317
318	=item CBOR tag 55799 (magic header)
319
320	The tag 55799 is ignored (this tag implements the magic header).
321
322	=item other CBOR tags
323
324	Tagged items consists of a numeric tag and another CBOR value. Tags not	358	Tagged items consists of a numeric tag and another CBOR value.
325	handled internally are currently converted into a L<CBOR::XS::Tagged>
326	object, which is simply a blessed array reference consisting of the
327	numeric tag value followed by the (decoded) CBOR value.
328		359
329	In the future, support for user-supplied conversions might get added.	360	See L<TAG HANDLING AND EXTENSIONS> and the description of C<< ->filter >>
		361	for details.
330		362
331	=item anything else	363	=item anything else
332		364
333	Anything else (e.g. unsupported simple values) will raise a decoding	365	Anything else (e.g. unsupported simple values) will raise a decoding
334	error.	366	error.
…		…
377	if you want.	409	if you want.
378		410
379	=item other blessed objects	411	=item other blessed objects
380		412
381	Other blessed objects are serialised via C<TO_CBOR> or C<FREEZE>. See	413	Other blessed objects are serialised via C<TO_CBOR> or C<FREEZE>. See
382	L<OBJECT SERIALISATION>, below, for details.	414	L<TAG HANDLING AND EXTENSIONS> for specific classes handled by this
		415	module, and L<OBJECT SERIALISATION> for generic object serialisation.
383		416
384	=item simple scalars	417	=item simple scalars
385		418
386	TODO
387	Simple Perl scalars (any scalar that is not a reference) are the most	419	Simple Perl scalars (any scalar that is not a reference) are the most
388	difficult objects to encode: CBOR::XS will encode undefined scalars as	420	difficult objects to encode: CBOR::XS will encode undefined scalars as
389	CBOR null values, scalars that have last been used in a string context	421	CBOR null values, scalars that have last been used in a string context
390	before encoding as CBOR strings, and anything else as number value:	422	before encoding as CBOR strings, and anything else as number value:
391		423
…		…
627	CBOR::XS::tag 24,	659	CBOR::XS::tag 24,
628	encode_cbor [1, 2, 3];	660	encode_cbor [1, 2, 3];
629		661
630	=head1 TAG HANDLING AND EXTENSIONS	662	=head1 TAG HANDLING AND EXTENSIONS
631		663
632	This section describes how this module handles specific tagged values and	664	This section describes how this module handles specific tagged values
633	extensions. If a tag is not mentioned here, then the default handling	665	and extensions. If a tag is not mentioned here and no additional filters
		666	are provided for it, then the default handling applies (creating a
634	applies (creating a CBOR::XS::Tagged object on decoding, and only encoding	667	CBOR::XS::Tagged object on decoding, and only encoding the tag when
635	the tag when explicitly requested).	668	explicitly requested).
		669
		670	Tags not handled specifically are currently converted into a
		671	L<CBOR::XS::Tagged> object, which is simply a blessed array reference
		672	consisting of the numeric tag value followed by the (decoded) CBOR value.
636		673
637	Future versions of this module reserve the right to special case	674	Future versions of this module reserve the right to special case
638	additional tags (such as bigfloat or base64url).	675	additional tags (such as base64url).
		676
		677	=head2 ENFORCED TAGS
		678
		679	These tags are always handled when decoding, and their handling cannot be
		680	overriden by the user.
639		681
640	=over 4	682	=over 4
641		683
642	=item <unassigned> (perl-object, L<http://cbor.schmorp.de/perl-object>)	684	=item 26 (perl-object, L<http://cbor.schmorp.de/perl-object>)
643		685
644	These tags are automatically created for serialisable objects using the	686	These tags are automatically created (and decoded) for serialisable
645	C<FREEZE/THAW> methods (the L<Types::Serialier> object serialisation	687	objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object
646	protocol).	688	serialisation protocol). See L<OBJECT SERIALISATION> for details.
647		689
648	=item <unassigned>, <unassigned> (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>)	690	=item 28, 29 (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>)
649		691
650	These tags are automatically decoded when encountered, resulting in	692	These tags are automatically decoded when encountered, resulting in
651	shared values in the decoded object. They are only encoded, however, when	693	shared values in the decoded object. They are only encoded, however, when
652	C<allow_sharable> is enabled.	694	C<allow_sharable> is enabled.
653		695
654	=item <unassigned>, <unassigned> (stringref-namespace, stringref, L <http://cbor.schmorp.de/stringref>)	696	=item 256, 25 (stringref-namespace, stringref, L <http://cbor.schmorp.de/stringref>)
655		697
656	These tags are automatically decoded when encountered. They are only	698	These tags are automatically decoded when encountered. They are only
657	encoded, however, when C<allow_stringref> is enabled.	699	encoded, however, when C<pack_strings> is enabled.
658		700
659	=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>)	701	=item 22098 (indirection, L<http://cbor.schmorp.de/indirection>)
660		702
661	This tag is automatically generated when a reference are encountered (with	703	This tag is automatically generated when a reference are encountered (with
662	the exception of hash and array refernces). It is converted to a reference	704	the exception of hash and array refernces). It is converted to a reference
…		…
666		708
667	This value is not generated on encoding (unless explicitly requested by	709	This value is not generated on encoding (unless explicitly requested by
668	the user), and is simply ignored when decoding.	710	the user), and is simply ignored when decoding.
669		711
670	=back	712	=back
		713
		714	=head2 NON-ENFORCED TAGS
		715
		716	These tags have default filters provided when decoding. Their handling can
		717	be overriden by changing the C<%CBOR::XS::FILTER> entry for the tag, or by
		718	providing a custom C<filter> callback when decoding.
		719
		720	When they result in decoding into a specific Perl class, the module
		721	usually provides a corresponding C<TO_CBOR> method as well.
		722
		723	When any of these need to load additional modules that are not part of the
		724	perl core distribution (e.g. L<URI>), it is (currently) up to the user to
		725	provide these modules. The decoding usually fails with an exception if the
		726	required module cannot be loaded.
		727
		728	=over 4
		729
		730	=item 2, 3 (positive/negative bignum)
		731
		732	These tags are decoded into L<Math::BigInt> objects. The corresponding
		733	C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR
		734	integers, and others into positive/negative CBOR bignums.
		735
		736	=item 4, 5 (decimal fraction/bigfloat)
		737
		738	Both decimal fractions and bigfloats are decoded into L<Math::BigFloat>
		739	objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always>
		740	encodes into a decimal fraction.
		741
		742	CBOR cannot represent bigfloats with I<very> large exponents - conversion
		743	of such big float objects is undefined.
		744
		745	Also, NaN and infinities are not encoded properly.
		746
		747	=item 21, 22, 23 (expected later JSON conversion)
		748
		749	CBOR::XS is not a CBOR-to-JSON converter, and will simply ignore these
		750	tags.
		751
		752	=item 32 (URI)
		753
		754	These objects decode into L<URI> objects. The corresponding
		755	C<URI::TO_CBOR> method again results in a CBOR URI value.
		756
		757	=back
		758
		759	=cut
		760
		761	our %FILTER = (
		762	# 0 # rfc4287 datetime, utf-8
		763	# 1 # unix timestamp, any
		764
		765	2 => sub { # pos bigint
		766	require Math::BigInt;
		767	Math::BigInt->new ("0x" . unpack "H*", pop)
		768	},
		769
		770	3 => sub { # neg bigint
		771	require Math::BigInt;
		772	-Math::BigInt->new ("0x" . unpack "H*", pop)
		773	},
		774
		775	4 => sub { # decimal fraction, array
		776	require Math::BigFloat;
		777	Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
		778	},
		779
		780	5 => sub { # bigfloat, array
		781	require Math::BigFloat;
		782	scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2)
		783	},
		784
		785	21 => sub { pop }, # expected conversion to base64url encoding
		786	22 => sub { pop }, # expected conversion to base64 encoding
		787	23 => sub { pop }, # expected conversion to base16 encoding
		788
		789	# 24 # embedded cbor, byte string
		790
		791	32 => sub {
		792	require URI;
		793	URI->new (pop)
		794	},
		795
		796	# 33 # base64url rfc4648, utf-8
		797	# 34 # base64 rfc46484, utf-8
		798	# 35 # regex pcre/ecma262, utf-8
		799	# 36 # mime message rfc2045, utf-8
		800	);
671		801
672		802
673	=head1 CBOR and JSON	803	=head1 CBOR and JSON
674		804
675	CBOR is supposed to implement a superset of the JSON data model, and is,	805	CBOR is supposed to implement a superset of the JSON data model, and is,
…		…
758	Please refrain from using rt.cpan.org or any other bug reporting	888	Please refrain from using rt.cpan.org or any other bug reporting
759	service. I put the contact address into my modules for a reason.	889	service. I put the contact address into my modules for a reason.
760		890
761	=cut	891	=cut
762		892
		893	our %FILTER = (
		894	# 0 # rfc4287 datetime, utf-8
		895	# 1 # unix timestamp, any
		896
		897	2 => sub { # pos bigint
		898	require Math::BigInt;
		899	Math::BigInt->new ("0x" . unpack "H*", pop)
		900	},
		901
		902	3 => sub { # neg bigint
		903	require Math::BigInt;
		904	-Math::BigInt->new ("0x" . unpack "H*", pop)
		905	},
		906
		907	4 => sub { # decimal fraction, array
		908	require Math::BigFloat;
		909	Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
		910	},
		911
		912	5 => sub { # bigfloat, array
		913	require Math::BigFloat;
		914	scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2)
		915	},
		916
		917	21 => sub { pop }, # expected conversion to base64url encoding
		918	22 => sub { pop }, # expected conversion to base64 encoding
		919	23 => sub { pop }, # expected conversion to base16 encoding
		920
		921	# 24 # embedded cbor, byte string
		922
		923	32 => sub {
		924	require URI;
		925	URI->new (pop)
		926	},
		927
		928	# 33 # base64url rfc4648, utf-8
		929	# 34 # base64 rfc46484, utf-8
		930	# 35 # regex pcre/ecma262, utf-8
		931	# 36 # mime message rfc2045, utf-8
		932	);
		933
		934	sub CBOR::XS::default_filter {
		935	&{ $FILTER{$_[0]} or return }
		936	}
		937
		938	sub URI::TO_CBOR {
		939	my $uri = $_[0]->as_string;
		940	utf8::upgrade $uri;
		941	CBOR::XS::tag 32, $uri
		942	}
		943
		944	sub Math::BigInt::TO_CBOR {
		945	if ($_[0] >= -2147483648 && $_[0] <= 2147483647) {
		946	$_[0]->numify
		947	} else {
		948	my $hex = substr $_[0]->as_hex, 2;
		949	$hex = "0$hex" if 1 & length $hex; # sigh
		950	CBOR::XS::tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex
		951	}
		952	}
		953
		954	sub Math::BigFloat::TO_CBOR {
		955	my ($m, $e) = $_[0]->parts;
		956	CBOR::XS::tag 4, [$e->numify, $m]
		957	}
		958
763	XSLoader::load "CBOR::XS", $VERSION;	959	XSLoader::load "CBOR::XS", $VERSION;
764		960
765	=head1 SEE ALSO	961	=head1 SEE ALSO
766		962
767	The L<JSON> and L<JSON::XS> modules that do similar, but human-readable,	963	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 1.21 by root, Wed Nov 20 16:29:02 2013 UTC vs. Revision 1.26 by root, Thu Nov 28 12:11:06 2013 UTC

Diff Legend

Comparing CBOR-XS/XS.pm (file contents):
Revision 1.21 by root, Wed Nov 20 16:29:02 2013 UTC vs.
Revision 1.26 by root, Thu Nov 28 12:11:06 2013 UTC