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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 1.24 by root, Fri Nov 22 16:18:59 2013 UTC

71 71
72package CBOR::XS; 72package CBOR::XS;
73 73
74use common::sense; 74use common::sense;
75 75
76our $VERSION = 0.08; 76our $VERSION = 0.09;
77our @ISA = qw(Exporter); 77our @ISA = qw(Exporter);
78 78
79our @EXPORT = qw(encode_cbor decode_cbor); 79our @EXPORT = qw(encode_cbor decode_cbor);
80 80
81use Exporter; 81use Exporter;
118strings. All boolean flags described below are by default I<disabled>. 118strings. All boolean flags described below are by default I<disabled>.
119 119
120The mutators for flags all return the CBOR object again and thus calls can 120The mutators for flags all return the CBOR object again and thus calls can
121be chained: 121be 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
230exception when it encounters anything it cannot encode as CBOR. 229exception when it encounters anything it cannot encode as CBOR.
231 230
232This option does not affect C<decode> in any way - string references will 231This option does not affect C<decode> in any way - string references will
233always be decoded properly if present. 232always be decoded properly if present.
234 233
234=item $cbor = $cbor->filter ([$cb->($tag, $value)])
235
236=item $cb_or_undef = $cbor->get_filter
237
238Sets or replaces the tagged value decoding filter (when C<$cb> is
239specified) or clears the filter (if no argument or C<undef> is provided).
240
241The filter callback is called only during decoding, when a non-enforced
242tagged value has been decoded (see L<TAG HANDLING AND EXTENSIONS> for a
243list of enforced tags). For specific tags, it's often better to provide a
244default converter using the C<%CBOR::XS::FILTER> hash (see below).
245
246The first argument is the numerical tag, the second is the (decoded) value
247that has been tagged.
248
249The filter function should return either exactly one value, which will
250replace the tagged value in the decoded data structure, or no values,
251which will result in default handling, which currently means the decoder
252creates a C<CBOR::XS::Tagged> object to hold the tag and the value.
253
254When the filter is cleared (the default state), the default filter
255function, C<CBOR::XS::default_filter>, is used. This function simply looks
256up the tag in the C<%CBOR::XS::FILTER> hash. If an entry exists it must be
257a code reference that is called with tag and value, and is responsible for
258decoding the value. If no entry exists, it returns no values.
259
260Example: decode all tags not handled internally into CBOR::XS::Tagged
261objects, with no other special handling (useful when working with
262potentially "unsafe" CBOR data).
263
264 CBOR::XS->new->filter (sub { })->decode ($cbor_data);
265
266Example: provide a global filter for tag 1347375694, converting the value
267into some string form.
268
269 $CBOR::XS::FILTER{1347375694} = sub {
270 my ($tag, $value);
271
272 "tag 1347375694 value $value"
273 };
274
235=item $cbor_data = $cbor->encode ($perl_scalar) 275=item $cbor_data = $cbor->encode ($perl_scalar)
236 276
237Converts the given Perl data structure (a scalar value) to its CBOR 277Converts the given Perl data structure (a scalar value) to its CBOR
238representation. 278representation.
239 279
307C<Types:Serialiser::false> and C<Types::Serialiser::error>, 347C<Types:Serialiser::false> and C<Types::Serialiser::error>,
308respectively. They are overloaded to act almost exactly like the numbers 348respectively. They are overloaded to act almost exactly like the numbers
309C<1> and C<0> (for true and false) or to throw an exception on access (for 349C<1> and C<0> (for true and false) or to throw an exception on access (for
310error). See the L<Types::Serialiser> manpage for details. 350error). See the L<Types::Serialiser> manpage for details.
311 351
312=item CBOR tag 256 (perl object) 352=item tagged values
313 353
314The tag value C<256> (TODO: pending iana registration) will be used
315to deserialise a Perl object serialised with C<FREEZE>. See L<OBJECT
316SERIALISATION>, below, for details.
317
318=item CBOR tag 55799 (magic header)
319
320The tag 55799 is ignored (this tag implements the magic header).
321
322=item other CBOR tags
323
324Tagged items consists of a numeric tag and another CBOR value. Tags not 354Tagged items consists of a numeric tag and another CBOR value.
325handled internally are currently converted into a L<CBOR::XS::Tagged>
326object, which is simply a blessed array reference consisting of the
327numeric tag value followed by the (decoded) CBOR value.
328 355
329In the future, support for user-supplied conversions might get added. 356See L<TAG HANDLING AND EXTENSIONS> and the description of C<< ->filter >>
357for details.
330 358
331=item anything else 359=item anything else
332 360
333Anything else (e.g. unsupported simple values) will raise a decoding 361Anything else (e.g. unsupported simple values) will raise a decoding
334error. 362error.
377if you want. 405if you want.
378 406
379=item other blessed objects 407=item other blessed objects
380 408
381Other blessed objects are serialised via C<TO_CBOR> or C<FREEZE>. See 409Other blessed objects are serialised via C<TO_CBOR> or C<FREEZE>. See
382L<OBJECT SERIALISATION>, below, for details. 410L<TAG HANDLING AND EXTENSIONS> for specific classes handled by this
411module, and L<OBJECT SERIALISATION> for generic object serialisation.
383 412
384=item simple scalars 413=item simple scalars
385 414
386TODO
387Simple Perl scalars (any scalar that is not a reference) are the most 415Simple Perl scalars (any scalar that is not a reference) are the most
388difficult objects to encode: CBOR::XS will encode undefined scalars as 416difficult objects to encode: CBOR::XS will encode undefined scalars as
389CBOR null values, scalars that have last been used in a string context 417CBOR null values, scalars that have last been used in a string context
390before encoding as CBOR strings, and anything else as number value: 418before encoding as CBOR strings, and anything else as number value:
391 419
627 CBOR::XS::tag 24, 655 CBOR::XS::tag 24,
628 encode_cbor [1, 2, 3]; 656 encode_cbor [1, 2, 3];
629 657
630=head1 TAG HANDLING AND EXTENSIONS 658=head1 TAG HANDLING AND EXTENSIONS
631 659
632This section describes how this module handles specific tagged values and 660This section describes how this module handles specific tagged values
633extensions. If a tag is not mentioned here, then the default handling 661and extensions. If a tag is not mentioned here and no additional filters
662are provided for it, then the default handling applies (creating a
634applies (creating a CBOR::XS::Tagged object on decoding, and only encoding 663CBOR::XS::Tagged object on decoding, and only encoding the tag when
635the tag when explicitly requested). 664explicitly requested).
665
666Tags not handled specifically are currently converted into a
667L<CBOR::XS::Tagged> object, which is simply a blessed array reference
668consisting of the numeric tag value followed by the (decoded) CBOR value.
636 669
637Future versions of this module reserve the right to special case 670Future versions of this module reserve the right to special case
638additional tags (such as bigfloat or base64url). 671additional tags (such as base64url).
672
673=head2 ENFORCED TAGS
674
675These tags are always handled when decoding, and their handling cannot be
676overriden by the user.
639 677
640=over 4 678=over 4
641 679
642=item <unassigned> (perl-object, L<http://cbor.schmorp.de/perl-object>) 680=item <unassigned> (perl-object, L<http://cbor.schmorp.de/perl-object>)
643 681
644These tags are automatically created for serialisable objects using the 682These tags are automatically created (and decoded) for serialisable
645C<FREEZE/THAW> methods (the L<Types::Serialier> object serialisation 683objects using the C<FREEZE/THAW> methods (the L<Types::Serialier> object
646protocol). 684serialisation protocol). See L<OBJECT SERIALISATION> for details.
647 685
648=item <unassigned>, <unassigned> (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>) 686=item <unassigned>, <unassigned> (sharable, sharedref, L <http://cbor.schmorp.de/value-sharing>)
649 687
650These tags are automatically decoded when encountered, resulting in 688These tags are automatically decoded when encountered, resulting in
651shared values in the decoded object. They are only encoded, however, when 689shared values in the decoded object. They are only encoded, however, when
666 704
667This value is not generated on encoding (unless explicitly requested by 705This value is not generated on encoding (unless explicitly requested by
668the user), and is simply ignored when decoding. 706the user), and is simply ignored when decoding.
669 707
670=back 708=back
709
710=head2 NON-ENFORCED TAGS
711
712These tags have default filters provided when decoding. Their handling can
713be overriden by changing the C<%CBOR::XS::FILTER> entry for the tag, or by
714providing a custom C<filter> callback when decoding.
715
716When they result in decoding into a specific Perl class, the module
717usually provides a corresponding C<TO_CBOR> method as well.
718
719When any of these need to load additional modules that are not part of the
720perl core distribution (e.g. L<URI>), it is (currently) up to the user to
721provide these modules. The decoding usually fails with an exception if the
722required module cannot be loaded.
723
724=over 4
725
726=item 2, 3 (positive/negative bignum)
727
728These tags are decoded into L<Math::BigInt> objects. The corresponding
729C<Math::BigInt::TO_CBOR> method encodes "small" bigints into normal CBOR
730integers, and others into positive/negative CBOR bignums.
731
732=item 4, 5 (decimal fraction/bigfloat)
733
734Both decimal fractions and bigfloats are decoded into L<Math::BigFloat>
735objects. The corresponding C<Math::BigFloat::TO_CBOR> method I<always>
736encodes into a decimal fraction.
737
738CBOR cannot represent bigfloats with I<very> large exponents - conversion
739of such big float objects is undefined.
740
741Also, NaN and infinities are not encoded properly.
742
743=item 21, 22, 23 (expected later JSON conversion)
744
745CBOR::XS is not a CBOR-to-JSON converter, and will simply ignore these
746tags.
747
748=item 32 (URI)
749
750These objects decode into L<URI> objects. The corresponding
751C<URI::TO_CBOR> method again results in a CBOR URI value.
752
753=back
754
755=cut
756
757our %FILTER = (
758 # 0 # rfc4287 datetime, utf-8
759 # 1 # unix timestamp, any
760
761 2 => sub { # pos bigint
762 require Math::BigInt;
763 Math::BigInt->new ("0x" . unpack "H*", pop)
764 },
765
766 3 => sub { # neg bigint
767 require Math::BigInt;
768 -Math::BigInt->new ("0x" . unpack "H*", pop)
769 },
770
771 4 => sub { # decimal fraction, array
772 require Math::BigFloat;
773 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
774 },
775
776 5 => sub { # bigfloat, array
777 require Math::BigFloat;
778 scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2)
779 },
780
781 21 => sub { pop }, # expected conversion to base64url encoding
782 22 => sub { pop }, # expected conversion to base64 encoding
783 23 => sub { pop }, # expected conversion to base16 encoding
784
785 # 24 # embedded cbor, byte string
786
787 32 => sub {
788 require URI;
789 URI->new (pop)
790 },
791
792 # 33 # base64url rfc4648, utf-8
793 # 34 # base64 rfc46484, utf-8
794 # 35 # regex pcre/ecma262, utf-8
795 # 36 # mime message rfc2045, utf-8
796);
671 797
672 798
673=head1 CBOR and JSON 799=head1 CBOR and JSON
674 800
675CBOR is supposed to implement a superset of the JSON data model, and is, 801CBOR is supposed to implement a superset of the JSON data model, and is,
758Please refrain from using rt.cpan.org or any other bug reporting 884Please refrain from using rt.cpan.org or any other bug reporting
759service. I put the contact address into my modules for a reason. 885service. I put the contact address into my modules for a reason.
760 886
761=cut 887=cut
762 888
889our %FILTER = (
890 # 0 # rfc4287 datetime, utf-8
891 # 1 # unix timestamp, any
892
893 2 => sub { # pos bigint
894 require Math::BigInt;
895 Math::BigInt->new ("0x" . unpack "H*", pop)
896 },
897
898 3 => sub { # neg bigint
899 require Math::BigInt;
900 -Math::BigInt->new ("0x" . unpack "H*", pop)
901 },
902
903 4 => sub { # decimal fraction, array
904 require Math::BigFloat;
905 Math::BigFloat->new ($_[1][1] . "E" . $_[1][0])
906 },
907
908 5 => sub { # bigfloat, array
909 require Math::BigFloat;
910 scalar Math::BigFloat->new ($_[1][1])->blsft ($_[1][0], 2)
911 },
912
913 21 => sub { pop }, # expected conversion to base64url encoding
914 22 => sub { pop }, # expected conversion to base64 encoding
915 23 => sub { pop }, # expected conversion to base16 encoding
916
917 # 24 # embedded cbor, byte string
918
919 32 => sub {
920 require URI;
921 URI->new (pop)
922 },
923
924 # 33 # base64url rfc4648, utf-8
925 # 34 # base64 rfc46484, utf-8
926 # 35 # regex pcre/ecma262, utf-8
927 # 36 # mime message rfc2045, utf-8
928);
929
930sub CBOR::XS::default_filter {
931 &{ $FILTER{$_[0]} or return }
932}
933
934sub URI::TO_CBOR {
935 my $uri = $_[0]->as_string;
936 utf8::upgrade $uri;
937 CBOR::XS::tag 32, $uri
938}
939
940sub Math::BigInt::TO_CBOR {
941 if ($_[0] >= -2147483648 && $_[0] <= 2147483647) {
942 $_[0]->numify
943 } else {
944 my $hex = substr $_[0]->as_hex, 2;
945 $hex = "0$hex" if 1 & length $hex; # sigh
946 CBOR::XS::tag $_[0] >= 0 ? 2 : 3, pack "H*", $hex
947 }
948}
949
950sub Math::BigFloat::TO_CBOR {
951 my ($m, $e) = $_[0]->parts;
952 CBOR::XS::tag 4, [$e->numify, $m]
953}
954
763XSLoader::load "CBOR::XS", $VERSION; 955XSLoader::load "CBOR::XS", $VERSION;
764 956
765=head1 SEE ALSO 957=head1 SEE ALSO
766 958
767The L<JSON> and L<JSON::XS> modules that do similar, but human-readable, 959The L<JSON> and L<JSON::XS> modules that do similar, but human-readable,

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