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Comparing JSON-XS/XS.pm (file contents):
Revision 1.39 by root, Mon Jun 11 02:58:10 2007 UTC vs.
Revision 1.43 by root, Sat Jun 23 23:49:29 2007 UTC

85 85
86package JSON::XS; 86package JSON::XS;
87 87
88use strict; 88use strict;
89 89
90BEGIN {
91 our $VERSION = '1.23'; 90our $VERSION = '1.3';
92 our @ISA = qw(Exporter); 91our @ISA = qw(Exporter);
93 92
94 our @EXPORT = qw(to_json from_json objToJson jsonToObj); 93our @EXPORT = qw(to_json from_json objToJson jsonToObj);
95 require Exporter;
96 94
97 require XSLoader; 95use Exporter;
98 XSLoader::load JSON::XS::, $VERSION; 96use XSLoader;
99}
100 97
101=head1 FUNCTIONAL INTERFACE 98=head1 FUNCTIONAL INTERFACE
102 99
103The following convinience methods are provided by this module. They are 100The following convinience methods are provided by this module. They are
104exported by default: 101exported by default:
126This function call is functionally identical to: 123This function call is functionally identical to:
127 124
128 $perl_scalar = JSON::XS->new->utf8->decode ($json_text) 125 $perl_scalar = JSON::XS->new->utf8->decode ($json_text)
129 126
130except being faster. 127except being faster.
128
129=item $is_boolean = JSON::XS::is_bool $scalar
130
131Returns true if the passed scalar represents either JSON::XS::true or
132JSON::XS::false, two constants that act like C<1> and C<0>, respectively
133and are used to represent JSON C<true> and C<false> values in Perl.
134
135See MAPPING, below, for more information on how JSON values are mapped to
136Perl.
131 137
132=back 138=back
133 139
134 140
135=head1 OBJECT-ORIENTED INTERFACE 141=head1 OBJECT-ORIENTED INTERFACE
432conversion details, but an integer may take slightly less memory and might 438conversion details, but an integer may take slightly less memory and might
433represent more values exactly than (floating point) numbers. 439represent more values exactly than (floating point) numbers.
434 440
435=item true, false 441=item true, false
436 442
437These JSON atoms become C<0>, C<1>, respectively. Information is lost in 443These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,
438this process. Future versions might represent those values differently, 444respectively. They are overloaded to act almost exactly like the numbers
439but they will be guarenteed to act like these integers would normally in 445C<1> and C<0>. You can check wether a scalar is a JSON boolean by using
440Perl. 446the C<JSON::XS::is_bool> function.
441 447
442=item null 448=item null
443 449
444A JSON null atom becomes C<undef> in Perl. 450A JSON null atom becomes C<undef> in Perl.
445 451
477C<1>, which get turned into C<false> and C<true> atoms in JSON. You can 483C<1>, which get turned into C<false> and C<true> atoms in JSON. You can
478also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. 484also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.
479 485
480 to_json [\0,JSON::XS::true] # yields [false,true] 486 to_json [\0,JSON::XS::true] # yields [false,true]
481 487
488=item JSON::XS::true, JSON::XS::false
489
490These special values become JSON true and JSON false values,
491respectively. You cna alos use C<\1> and C<\0> directly if you want.
492
482=item blessed objects 493=item blessed objects
483 494
484Blessed objects are not allowed. JSON::XS currently tries to encode their 495Blessed objects are not allowed. JSON::XS currently tries to encode their
485underlying representation (hash- or arrayref), but this behaviour might 496underlying representation (hash- or arrayref), but this behaviour might
486change in future versions. 497change in future versions.
614 625
615You often hear that JSON is a subset (or a close subset) of YAML. This is, 626You often hear that JSON is a subset (or a close subset) of YAML. This is,
616however, a mass hysteria and very far from the truth. In general, there is 627however, a mass hysteria and very far from the truth. In general, there is
617no way to configure JSON::XS to output a data structure as valid YAML. 628no way to configure JSON::XS to output a data structure as valid YAML.
618 629
619If you really must use JSON::XS to generate YAML, you should this 630If you really must use JSON::XS to generate YAML, you should use this
620algorithm (subject to change in future versions): 631algorithm (subject to change in future versions):
621 632
622 my $to_yaml = JSON::XS->new->utf8->space_after (1); 633 my $to_yaml = JSON::XS->new->utf8->space_after (1);
623 my $yaml = $to_yaml->encode ($ref) . "\n"; 634 my $yaml = $to_yaml->encode ($ref) . "\n";
624 635
625This will usually generate JSON texts that also parse as valid 636This will usually generate JSON texts that also parse as valid
626YAML. Please note that YAML has hardcoded limits on object key lengths 637YAML. Please note that YAML has hardcoded limits on (simple) object key
627that JSON doesn't have, so you should make sure that your hash keys are 638lengths that JSON doesn't have, so you should make sure that your hash
628noticably shorter than 1024 characters. 639keys are noticably shorter than the 1024 characters YAML allows.
629 640
630There might be other incompatibilities that I am not aware of. In general 641There might be other incompatibilities that I am not aware of. In general
631you should not try to generate YAML with a JSON generator or vice versa, 642you should not try to generate YAML with a JSON generator or vice versa,
632or try to parse JSON with a YAML parser or vice versa. 643or try to parse JSON with a YAML parser or vice versa: chances are high
644that you will run into severe interoperability problems.
633 645
634 646
635=head2 SPEED 647=head2 SPEED
636 648
637It seems that JSON::XS is surprisingly fast, as shown in the following 649It seems that JSON::XS is surprisingly fast, as shown in the following
651shrink). Higher is better: 663shrink). Higher is better:
652 664
653 module | encode | decode | 665 module | encode | decode |
654 -----------|------------|------------| 666 -----------|------------|------------|
655 JSON | 7645.468 | 4208.613 | 667 JSON | 7645.468 | 4208.613 |
656 JSON::DWIW | 68534.379 | 79437.576 | 668 JSON::DWIW | 40721.398 | 77101.176 |
657 JSON::PC | 65948.176 | 78251.940 | 669 JSON::PC | 65948.176 | 78251.940 |
658 JSON::Syck | 23379.621 | 28416.694 | 670 JSON::Syck | 22844.793 | 26479.192 |
659 JSON::XS | 388361.481 | 199728.762 | 671 JSON::XS | 388361.481 | 199728.762 |
660 JSON::XS/2 | 218453.333 | 192399.266 | 672 JSON::XS/2 | 218453.333 | 192399.266 |
661 JSON::XS/3 | 338250.323 | 192399.266 | 673 JSON::XS/3 | 338250.323 | 192399.266 |
662 Storable | 15732.573 | 28571.553 | 674 Storable | 15779.925 | 14169.946 |
663 -----------+------------+------------+ 675 -----------+------------+------------+
664 676
665That is, JSON::XS is about five times faster than JSON::DWIW on encoding, 677That is, JSON::XS is about five times faster than JSON::DWIW on encoding,
666about three times faster on decoding, and over fourty times faster 678about three times faster on decoding, and over fourty times faster
667than JSON, even with pretty-printing and key sorting. It also compares 679than JSON, even with pretty-printing and key sorting. It also compares
671search API (http://nanoref.com/yahooapis/mgPdGg): 683search API (http://nanoref.com/yahooapis/mgPdGg):
672 684
673 module | encode | decode | 685 module | encode | decode |
674 -----------|------------|------------| 686 -----------|------------|------------|
675 JSON | 254.685 | 37.665 | 687 JSON | 254.685 | 37.665 |
676 JSON::DWIW | 1014.244 | 1087.678 | 688 JSON::DWIW | 843.343 | 1049.731 |
677 JSON::PC | 3602.116 | 2307.352 | 689 JSON::PC | 3602.116 | 2307.352 |
678 JSON::Syck | 558.035 | 776.263 | 690 JSON::Syck | 505.107 | 787.899 |
679 JSON::XS | 5747.196 | 3543.684 | 691 JSON::XS | 5747.196 | 3690.220 |
680 JSON::XS/2 | 3968.121 | 3589.170 | 692 JSON::XS/2 | 3968.121 | 3676.634 |
681 JSON::XS/3 | 6105.246 | 3561.134 | 693 JSON::XS/3 | 6105.246 | 3662.508 |
682 Storable | 4456.337 | 5320.020 | 694 Storable | 4417.337 | 5285.161 |
683 -----------+------------+------------+ 695 -----------+------------+------------+
684 696
685Again, JSON::XS leads by far. 697Again, JSON::XS leads by far (except for Storable which non-surprisingly
698decodes faster).
686 699
687On large strings containing lots of high unicode characters, some modules 700On large strings containing lots of high unicode characters, some modules
688(such as JSON::PC) seem to decode faster than JSON::XS, but the result 701(such as JSON::PC) seem to decode faster than JSON::XS, but the result
689will be broken due to missing (or wrong) unicode handling. Others refuse 702will be broken due to missing (or wrong) unicode handling. Others refuse
690to decode or encode properly, so it was impossible to prepare a fair 703to decode or encode properly, so it was impossible to prepare a fair
718 731
719And last but least, something else could bomb you that I forgot to think 732And last but least, something else could bomb you that I forgot to think
720of. In that case, you get to keep the pieces. I am always open for hints, 733of. In that case, you get to keep the pieces. I am always open for hints,
721though... 734though...
722 735
736If you are using JSON::XS to return packets to consumption
737by javascript scripts in a browser you should have a look at
738L<http://jpsykes.com/47/practical-csrf-and-json-security> to see wether
739you are vulnerable to some common attack vectors (which really are browser
740design bugs, but it is still you who will have to deal with it, as major
741browser developers care only for features, not about doing security
742right).
743
723 744
724=head1 BUGS 745=head1 BUGS
725 746
726While the goal of this module is to be correct, that unfortunately does 747While the goal of this module is to be correct, that unfortunately does
727not mean its bug-free, only that I think its design is bug-free. It is 748not mean its bug-free, only that I think its design is bug-free. It is
728still relatively early in its development. If you keep reporting bugs they 749still relatively early in its development. If you keep reporting bugs they
729will be fixed swiftly, though. 750will be fixed swiftly, though.
730 751
731=cut 752=cut
732 753
754our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" };
755our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" };
756
733sub true() { \1 } 757sub true() { $true }
734sub false() { \0 } 758sub false() { $false }
759
760sub is_bool($) {
761 UNIVERSAL::isa $_[0], "JSON::XS::Boolean"
762 or UNIVERSAL::isa $_[0], "JSON::Literal"
763}
764
765XSLoader::load "JSON::XS", $VERSION;
766
767package JSON::XS::Boolean;
768
769use overload
770 "0+" => sub { ${$_[0]} },
771 "++" => sub { $_[0] = ${$_[0]} + 1 },
772 "--" => sub { $_[0] = ${$_[0]} - 1 },
773 fallback => 1;
735 774
7361; 7751;
737 776
738=head1 AUTHOR 777=head1 AUTHOR
739 778

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