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Comparing JSON-XS/XS.pm (file contents):
Revision 1.34 by root, Wed May 9 16:33:53 2007 UTC vs.
Revision 1.39 by root, Mon Jun 11 02:58:10 2007 UTC

… …
86package JSON::XS; 86package JSON::XS;
87 87
88use strict; 88use strict;
89 89
90BEGIN { 90BEGIN {
91 our $VERSION = '1.2'; 91 our $VERSION = '1.23';
92 our @ISA = qw(Exporter); 92 our @ISA = qw(Exporter);
93 93
94 our @EXPORT = qw(to_json from_json objToJson jsonToObj); 94 our @EXPORT = qw(to_json from_json objToJson jsonToObj);
95 require Exporter; 95 require Exporter;
96 96
… …
402 402
403For the more enlightened: note that in the following descriptions, 403For the more enlightened: note that in the following descriptions,
404lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> 404lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl>
405refers to the abstract Perl language itself. 405refers to the abstract Perl language itself.
406 406
407
407=head2 JSON -> PERL 408=head2 JSON -> PERL
408 409
409=over 4 410=over 4
410 411
411=item object 412=item object
… …
441=item null 442=item null
442 443
443A JSON null atom becomes C<undef> in Perl. 444A JSON null atom becomes C<undef> in Perl.
444 445
445=back 446=back
447
446 448
447=head2 PERL -> JSON 449=head2 PERL -> JSON
448 450
449The mapping from Perl to JSON is slightly more difficult, as Perl is a 451The mapping from Perl to JSON is slightly more difficult, as Perl is a
450truly typeless language, so we can only guess which JSON type is meant by 452truly typeless language, so we can only guess which JSON type is meant by
… …
605 607
606Does not check input for validity. 608Does not check input for validity.
607 609
608=back 610=back
609 611
612
613=head2 JSON and YAML
614
615You 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
617no way to configure JSON::XS to output a data structure as valid YAML.
618
619If you really must use JSON::XS to generate YAML, you should this
620algorithm (subject to change in future versions):
621
622 my $to_yaml = JSON::XS->new->utf8->space_after (1);
623 my $yaml = $to_yaml->encode ($ref) . "\n";
624
625This will usually generate JSON texts that also parse as valid
626YAML. Please note that YAML has hardcoded limits on object key lengths
627that JSON doesn't have, so you should make sure that your hash keys are
628noticably shorter than 1024 characters.
629
630There 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,
632or try to parse JSON with a YAML parser or vice versa.
633
634
610=head2 SPEED 635=head2 SPEED
611 636
612It seems that JSON::XS is surprisingly fast, as shown in the following 637It seems that JSON::XS is surprisingly fast, as shown in the following
613tables. They have been generated with the help of the C<eg/bench> program 638tables. They have been generated with the help of the C<eg/bench> program
614in the JSON::XS distribution, to make it easy to compare on your own 639in the JSON::XS distribution, to make it easy to compare on your own
615system. 640system.
616 641
617First comes a comparison between various modules using a very short JSON 642First comes a comparison between various modules using a very short
618string: 643single-line JSON string:
619 644
620 {"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null} 645 {"method": "handleMessage", "params": ["user1", "we were just talking"], \
646 "id": null, "array":[1,11,234,-5,1e5,1e7, true, false]}
621 647
622It shows the number of encodes/decodes per second (JSON::XS uses the 648It shows the number of encodes/decodes per second (JSON::XS uses
623functional interface, while JSON::XS/2 uses the OO interface with 649the functional interface, while JSON::XS/2 uses the OO interface
624pretty-printing and hashkey sorting enabled). Higher is better: 650with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables
651shrink). Higher is better:
625 652
626 module | encode | decode | 653 module | encode | decode |
627 -----------|------------|------------| 654 -----------|------------|------------|
628 JSON | 11488.516 | 7823.035 | 655 JSON | 7645.468 | 4208.613 |
629 JSON::DWIW | 94708.054 | 129094.260 | 656 JSON::DWIW | 68534.379 | 79437.576 |
630 JSON::PC | 63884.157 | 128528.212 | 657 JSON::PC | 65948.176 | 78251.940 |
631 JSON::Syck | 34898.677 | 42096.911 | 658 JSON::Syck | 23379.621 | 28416.694 |
632 JSON::XS | 654027.064 | 396423.669 | 659 JSON::XS | 388361.481 | 199728.762 |
633 JSON::XS/2 | 371564.190 | 371725.613 | 660 JSON::XS/2 | 218453.333 | 192399.266 |
661 JSON::XS/3 | 338250.323 | 192399.266 |
662 Storable | 15732.573 | 28571.553 |
634 -----------+------------+------------+ 663 -----------+------------+------------+
635 664
636That is, JSON::XS is more than six times faster than JSON::DWIW on 665That is, JSON::XS is about five times faster than JSON::DWIW on encoding,
637encoding, more than three times faster on decoding, and about thirty times 666about three times faster on decoding, and over fourty times faster
638faster than JSON, even with pretty-printing and key sorting. 667than JSON, even with pretty-printing and key sorting. It also compares
668favourably to Storable for small amounts of data.
639 669
640Using a longer test string (roughly 18KB, generated from Yahoo! Locals 670Using a longer test string (roughly 18KB, generated from Yahoo! Locals
641search API (http://nanoref.com/yahooapis/mgPdGg): 671search API (http://nanoref.com/yahooapis/mgPdGg):
642 672
643 module | encode | decode | 673 module | encode | decode |
644 -----------|------------|------------| 674 -----------|------------|------------|
645 JSON | 273.023 | 44.674 | 675 JSON | 254.685 | 37.665 |
646 JSON::DWIW | 1089.383 | 1145.704 | 676 JSON::DWIW | 1014.244 | 1087.678 |
647 JSON::PC | 3097.419 | 2393.921 | 677 JSON::PC | 3602.116 | 2307.352 |
648 JSON::Syck | 514.060 | 843.053 | 678 JSON::Syck | 558.035 | 776.263 |
649 JSON::XS | 6479.668 | 3636.364 | 679 JSON::XS | 5747.196 | 3543.684 |
650 JSON::XS/2 | 3774.221 | 3599.124 | 680 JSON::XS/2 | 3968.121 | 3589.170 |
681 JSON::XS/3 | 6105.246 | 3561.134 |
682 Storable | 4456.337 | 5320.020 |
651 -----------+------------+------------+ 683 -----------+------------+------------+
652 684
653Again, JSON::XS leads by far. 685Again, JSON::XS leads by far.
654 686
655On large strings containing lots of high unicode characters, some modules 687On large strings containing lots of high unicode characters, some modules

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