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Comparing JSON-XS/XS.pm (file contents):
Revision 1.47 by root, Mon Jun 25 06:57:42 2007 UTC vs.
Revision 1.51 by root, Mon Jul 2 01:12:27 2007 UTC

… …
9 # exported functions, they croak on error 9 # exported functions, they croak on error
10 # and expect/generate UTF-8 10 # and expect/generate UTF-8
11 11
12 $utf8_encoded_json_text = to_json $perl_hash_or_arrayref; 12 $utf8_encoded_json_text = to_json $perl_hash_or_arrayref;
13 $perl_hash_or_arrayref = from_json $utf8_encoded_json_text; 13 $perl_hash_or_arrayref = from_json $utf8_encoded_json_text;
14
15 # objToJson and jsonToObj aliases to to_json and from_json
16 # are exported for compatibility to the JSON module,
17 # but should not be used in new code.
18 14
19 # OO-interface 15 # OO-interface
20 16
21 $coder = JSON::XS->new->ascii->pretty->allow_nonref; 17 $coder = JSON::XS->new->ascii->pretty->allow_nonref;
22 $pretty_printed_unencoded = $coder->encode ($perl_scalar); 18 $pretty_printed_unencoded = $coder->encode ($perl_scalar);
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88use strict; 84use strict;
89 85
90our $VERSION = '1.4'; 86our $VERSION = '1.4';
91our @ISA = qw(Exporter); 87our @ISA = qw(Exporter);
92 88
93our @EXPORT = qw(to_json from_json objToJson jsonToObj); 89our @EXPORT = qw(to_json from_json);
94 90
95use Exporter; 91use Exporter;
96use XSLoader; 92use XSLoader;
97 93
98=head1 FUNCTIONAL INTERFACE 94=head1 FUNCTIONAL INTERFACE
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351future, global hooks might get installed that influence C<decode> and are 347future, global hooks might get installed that influence C<decode> and are
352enabled by this setting. 348enabled by this setting.
353 349
354If C<$enable> is false, then the C<allow_blessed> setting will decide what 350If C<$enable> is false, then the C<allow_blessed> setting will decide what
355to do when a blessed object is found. 351to do when a blessed object is found.
352
353=item $json = $json->filter_json_object ([$coderef])
354
355When C<$coderef> is specified, it will be called from C<decode> each
356time it decodes a JSON object. The only argument is a reference to the
357newly-created hash. If the code references returns a single scalar (which
358need not be a reference), this value (i.e. a copy of that scalar to avoid
359aliasing) is inserted into the deserialised data structure. If it returns
360an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the
361original deserialised hash will be inserted. This setting can slow down
362decoding considerably.
363
364When C<$coderef> is omitted or undefined, C<decode> will not change the
365deserialised hash in any way. This is maximally fast.
366
367Example, convert all JSON objects into the integer 5:
368
369 my $js = JSON::XS->new->filter_json_object (sub { 5 });
370 # returns [5]
371 $js->decode ('[{}]')
372 # throw an exception because allow_nonref is not enabled:
373 $js->decode ('{"a":1, "b":2}');
374
375=item $json = $json->filter_json_single_key_object ([$coderef])
376
377Works like C<filter_json_object>, but is only called for JSON objects
378having only a single key.
379
380This C<$coderef> is called before the one specified via
381C<filter_json_object>, if any. If it returns something, that will be
382inserted into the data structure. If it returns nothing, the callback
383from C<filter_json_object> will be called next. If you want to force
384insertion of single-key objects even in the presence of a mutating
385C<filter_json_object> callback, simply return the passed hash.
386
387As this callback gets called less often then the C<filter_json_object>
388one, decoding speed will not usually suffer as much. Therefore, single-key
389objects make excellent targets to serialise Perl objects into, especially
390as single-key JSON objects are as close to the type-tagged value concept
391as JSON gets (its basically an ID/VALUE tuple). Of course, JSON does not
392support this in any way, so you need to make sure your data never looks
393like a serialised Perl hash.
394
395Typical names for the single object key are C<__class_whatever__>, or
396C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even
397things like C<__class_md5sum(classname)__>, to reduce the risk of clashing
398with real hashes.
399
400Example, decode JSON objects of the form C<< { "__widget__" => <id> } >>
401into the corresponding C<< $WIDGET{<id>} >> object:
402
403 # return whatever is in $WIDGET{5}:
404 JSON::XS
405 ->new
406 ->filter_json_single_key_object (sub {
407 exists $_[0]{__widget__}
408 ? $WIDGET{ $_[0]{__widget__} }
409 : ()
410 })
411 ->decode ('{"__widget__": 5')
412
413 # this can be used with a TO_JSON method in some "widget" class
414 # for serialisation to json:
415 sub WidgetBase::TO_JSON {
416 my ($self) = @_;
417
418 unless ($self->{id}) {
419 $self->{id} = ..get..some..id..;
420 $WIDGET{$self->{id}} = $self;
421 }
422
423 { __widget__ => $self->{id} }
424 }
356 425
357=item $json = $json->shrink ([$enable]) 426=item $json = $json->shrink ([$enable])
358 427
359Perl usually over-allocates memory a bit when allocating space for 428Perl usually over-allocates memory a bit when allocating space for
360strings. This flag optionally resizes strings generated by either 429strings. This flag optionally resizes strings generated by either
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711It shows the number of encodes/decodes per second (JSON::XS uses 780It shows the number of encodes/decodes per second (JSON::XS uses
712the functional interface, while JSON::XS/2 uses the OO interface 781the functional interface, while JSON::XS/2 uses the OO interface
713with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables 782with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables
714shrink). Higher is better: 783shrink). Higher is better:
715 784
785 Storable | 15779.925 | 14169.946 |
786 -----------+------------+------------+
716 module | encode | decode | 787 module | encode | decode |
717 -----------|------------|------------| 788 -----------|------------|------------|
718 JSON | 7645.468 | 4208.613 | 789 JSON | 4990.842 | 4088.813 |
719 JSON::DWIW | 40721.398 | 77101.176 | 790 JSON::DWIW | 51653.990 | 71575.154 |
720 JSON::PC | 65948.176 | 78251.940 | 791 JSON::PC | 65948.176 | 74631.744 |
721 JSON::Syck | 22844.793 | 26479.192 | 792 JSON::PP | 8931.652 | 3817.168 |
793 JSON::Syck | 24877.248 | 27776.848 |
722 JSON::XS | 388361.481 | 199728.762 | 794 JSON::XS | 388361.481 | 227951.304 |
723 JSON::XS/2 | 218453.333 | 192399.266 | 795 JSON::XS/2 | 227951.304 | 218453.333 |
724 JSON::XS/3 | 338250.323 | 192399.266 | 796 JSON::XS/3 | 338250.323 | 218453.333 |
725 Storable | 15779.925 | 14169.946 | 797 Storable | 16500.016 | 135300.129 |
726 -----------+------------+------------+ 798 -----------+------------+------------+
727 799
728That is, JSON::XS is about five times faster than JSON::DWIW on encoding, 800That is, JSON::XS is about five times faster than JSON::DWIW on encoding,
729about three times faster on decoding, and over fourty times faster 801about three times faster on decoding, and over fourty times faster
730than JSON, even with pretty-printing and key sorting. It also compares 802than JSON, even with pretty-printing and key sorting. It also compares
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733Using a longer test string (roughly 18KB, generated from Yahoo! Locals 805Using a longer test string (roughly 18KB, generated from Yahoo! Locals
734search API (http://nanoref.com/yahooapis/mgPdGg): 806search API (http://nanoref.com/yahooapis/mgPdGg):
735 807
736 module | encode | decode | 808 module | encode | decode |
737 -----------|------------|------------| 809 -----------|------------|------------|
738 JSON | 254.685 | 37.665 | 810 JSON | 55.260 | 34.971 |
739 JSON::DWIW | 843.343 | 1049.731 | 811 JSON::DWIW | 825.228 | 1082.513 |
740 JSON::PC | 3602.116 | 2307.352 | 812 JSON::PC | 3571.444 | 2394.829 |
813 JSON::PP | 210.987 | 32.574 |
741 JSON::Syck | 505.107 | 787.899 | 814 JSON::Syck | 552.551 | 787.544 |
742 JSON::XS | 5747.196 | 3690.220 | 815 JSON::XS | 5780.463 | 4854.519 |
743 JSON::XS/2 | 3968.121 | 3676.634 | 816 JSON::XS/2 | 3869.998 | 4798.975 |
744 JSON::XS/3 | 6105.246 | 3662.508 | 817 JSON::XS/3 | 5862.880 | 4798.975 |
745 Storable | 4417.337 | 5285.161 | 818 Storable | 4445.002 | 5235.027 |
746 -----------+------------+------------+ 819 -----------+------------+------------+
747 820
748Again, JSON::XS leads by far (except for Storable which non-surprisingly 821Again, JSON::XS leads by far (except for Storable which non-surprisingly
749decodes faster). 822decodes faster).
750 823
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802still relatively early in its development. If you keep reporting bugs they 875still relatively early in its development. If you keep reporting bugs they
803will be fixed swiftly, though. 876will be fixed swiftly, though.
804 877
805=cut 878=cut
806 879
807our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; 880our $true = do { bless \(my $dummy = "1"), "JSON::XS::Boolean" };
808our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; 881our $false = do { bless \(my $dummy = "0"), "JSON::XS::Boolean" };
809 882
810sub true() { $true } 883sub true() { $true }
811sub false() { $false } 884sub false() { $false }
812 885
813sub is_bool($) { 886sub is_bool($) {

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