… | |
… | |
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); |
… | |
… | |
85 | |
81 | |
86 | package JSON::XS; |
82 | package JSON::XS; |
87 | |
83 | |
88 | use strict; |
84 | use strict; |
89 | |
85 | |
90 | BEGIN { |
|
|
91 | our $VERSION = '1.21'; |
86 | our $VERSION = '1.5'; |
92 | our @ISA = qw(Exporter); |
87 | our @ISA = qw(Exporter); |
93 | |
88 | |
94 | our @EXPORT = qw(to_json from_json objToJson jsonToObj); |
89 | our @EXPORT = qw(to_json from_json); |
95 | require Exporter; |
|
|
96 | |
90 | |
97 | require XSLoader; |
91 | use Exporter; |
98 | XSLoader::load JSON::XS::, $VERSION; |
92 | use XSLoader; |
99 | } |
|
|
100 | |
93 | |
101 | =head1 FUNCTIONAL INTERFACE |
94 | =head1 FUNCTIONAL INTERFACE |
102 | |
95 | |
103 | The following convinience methods are provided by this module. They are |
96 | The following convinience methods are provided by this module. They are |
104 | exported by default: |
97 | exported by default: |
… | |
… | |
126 | This function call is functionally identical to: |
119 | This function call is functionally identical to: |
127 | |
120 | |
128 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
121 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
129 | |
122 | |
130 | except being faster. |
123 | except being faster. |
|
|
124 | |
|
|
125 | =item $is_boolean = JSON::XS::is_bool $scalar |
|
|
126 | |
|
|
127 | Returns true if the passed scalar represents either JSON::XS::true or |
|
|
128 | JSON::XS::false, two constants that act like C<1> and C<0>, respectively |
|
|
129 | and are used to represent JSON C<true> and C<false> values in Perl. |
|
|
130 | |
|
|
131 | See MAPPING, below, for more information on how JSON values are mapped to |
|
|
132 | Perl. |
131 | |
133 | |
132 | =back |
134 | =back |
133 | |
135 | |
134 | |
136 | |
135 | =head1 OBJECT-ORIENTED INTERFACE |
137 | =head1 OBJECT-ORIENTED INTERFACE |
… | |
… | |
276 | |
278 | |
277 | Example, space_before and indent disabled, space_after enabled: |
279 | Example, space_before and indent disabled, space_after enabled: |
278 | |
280 | |
279 | {"key": "value"} |
281 | {"key": "value"} |
280 | |
282 | |
|
|
283 | =item $json = $json->relaxed ([$enable]) |
|
|
284 | |
|
|
285 | If C<$enable> is true (or missing), then C<decode> will accept some |
|
|
286 | extensions to normal JSON syntax (see below). C<encode> will not be |
|
|
287 | affected in anyway. I<Be aware that this option makes you accept invalid |
|
|
288 | JSON texts as if they were valid!>. I suggest only to use this option to |
|
|
289 | parse application-specific files written by humans (configuration files, |
|
|
290 | resource files etc.) |
|
|
291 | |
|
|
292 | If C<$enable> is false (the default), then C<decode> will only accept |
|
|
293 | valid JSON texts. |
|
|
294 | |
|
|
295 | Currently accepted extensions are: |
|
|
296 | |
|
|
297 | =over 4 |
|
|
298 | |
|
|
299 | =item * list items can have an end-comma |
|
|
300 | |
|
|
301 | JSON I<separates> array elements and key-value pairs with commas. This |
|
|
302 | can be annoying if you write JSON texts manually and want to be able to |
|
|
303 | quickly append elements, so this extension accepts comma at the end of |
|
|
304 | such items not just between them: |
|
|
305 | |
|
|
306 | [ |
|
|
307 | 1, |
|
|
308 | 2, <- this comma not normally allowed |
|
|
309 | ] |
|
|
310 | { |
|
|
311 | "k1": "v1", |
|
|
312 | "k2": "v2", <- this comma not normally allowed |
|
|
313 | } |
|
|
314 | |
|
|
315 | =item * shell-style '#'-comments |
|
|
316 | |
|
|
317 | Whenever JSON allows whitespace, shell-style comments are additionally |
|
|
318 | allowed. They are terminated by the first carriage-return or line-feed |
|
|
319 | character, after which more white-space and comments are allowed. |
|
|
320 | |
|
|
321 | [ |
|
|
322 | 1, # this comment not allowed in JSON |
|
|
323 | # neither this one... |
|
|
324 | ] |
|
|
325 | |
|
|
326 | =back |
|
|
327 | |
281 | =item $json = $json->canonical ([$enable]) |
328 | =item $json = $json->canonical ([$enable]) |
282 | |
329 | |
283 | If C<$enable> is true (or missing), then the C<encode> method will output JSON objects |
330 | If C<$enable> is true (or missing), then the C<encode> method will output JSON objects |
284 | by sorting their keys. This is adding a comparatively high overhead. |
331 | by sorting their keys. This is adding a comparatively high overhead. |
285 | |
332 | |
… | |
… | |
309 | Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>, |
356 | Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>, |
310 | resulting in an invalid JSON text: |
357 | resulting in an invalid JSON text: |
311 | |
358 | |
312 | JSON::XS->new->allow_nonref->encode ("Hello, World!") |
359 | JSON::XS->new->allow_nonref->encode ("Hello, World!") |
313 | => "Hello, World!" |
360 | => "Hello, World!" |
|
|
361 | |
|
|
362 | =item $json = $json->allow_blessed ([$enable]) |
|
|
363 | |
|
|
364 | If C<$enable> is true (or missing), then the C<encode> method will not |
|
|
365 | barf when it encounters a blessed reference. Instead, the value of the |
|
|
366 | B<convert_blessed> option will decide wether C<null> (C<convert_blessed> |
|
|
367 | disabled or no C<to_json> method found) or a representation of the |
|
|
368 | object (C<convert_blessed> enabled and C<to_json> method found) is being |
|
|
369 | encoded. Has no effect on C<decode>. |
|
|
370 | |
|
|
371 | If C<$enable> is false (the default), then C<encode> will throw an |
|
|
372 | exception when it encounters a blessed object. |
|
|
373 | |
|
|
374 | =item $json = $json->convert_blessed ([$enable]) |
|
|
375 | |
|
|
376 | If C<$enable> is true (or missing), then C<encode>, upon encountering a |
|
|
377 | blessed object, will check for the availability of the C<TO_JSON> method |
|
|
378 | on the object's class. If found, it will be called in scalar context |
|
|
379 | and the resulting scalar will be encoded instead of the object. If no |
|
|
380 | C<TO_JSON> method is found, the value of C<allow_blessed> will decide what |
|
|
381 | to do. |
|
|
382 | |
|
|
383 | The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON> |
|
|
384 | returns other blessed objects, those will be handled in the same |
|
|
385 | way. C<TO_JSON> must take care of not causing an endless recursion cycle |
|
|
386 | (== crash) in this case. The name of C<TO_JSON> was chosen because other |
|
|
387 | methods called by the Perl core (== not by the user of the object) are |
|
|
388 | usually in upper case letters and to avoid collisions with the C<to_json> |
|
|
389 | function. |
|
|
390 | |
|
|
391 | This setting does not yet influence C<decode> in any way, but in the |
|
|
392 | future, global hooks might get installed that influence C<decode> and are |
|
|
393 | enabled by this setting. |
|
|
394 | |
|
|
395 | If C<$enable> is false, then the C<allow_blessed> setting will decide what |
|
|
396 | to do when a blessed object is found. |
|
|
397 | |
|
|
398 | =item $json = $json->filter_json_object ([$coderef->($hashref)]) |
|
|
399 | |
|
|
400 | When C<$coderef> is specified, it will be called from C<decode> each |
|
|
401 | time it decodes a JSON object. The only argument is a reference to the |
|
|
402 | newly-created hash. If the code references returns a single scalar (which |
|
|
403 | need not be a reference), this value (i.e. a copy of that scalar to avoid |
|
|
404 | aliasing) is inserted into the deserialised data structure. If it returns |
|
|
405 | an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the |
|
|
406 | original deserialised hash will be inserted. This setting can slow down |
|
|
407 | decoding considerably. |
|
|
408 | |
|
|
409 | When C<$coderef> is omitted or undefined, any existing callback will |
|
|
410 | be removed and C<decode> will not change the deserialised hash in any |
|
|
411 | way. |
|
|
412 | |
|
|
413 | Example, convert all JSON objects into the integer 5: |
|
|
414 | |
|
|
415 | my $js = JSON::XS->new->filter_json_object (sub { 5 }); |
|
|
416 | # returns [5] |
|
|
417 | $js->decode ('[{}]') |
|
|
418 | # throw an exception because allow_nonref is not enabled |
|
|
419 | # so a lone 5 is not allowed. |
|
|
420 | $js->decode ('{"a":1, "b":2}'); |
|
|
421 | |
|
|
422 | =item $json = $json->filter_json_single_key_object ($key [=> $coderef->($value)]) |
|
|
423 | |
|
|
424 | Works remotely similar to C<filter_json_object>, but is only called for |
|
|
425 | JSON objects having a single key named C<$key>. |
|
|
426 | |
|
|
427 | This C<$coderef> is called before the one specified via |
|
|
428 | C<filter_json_object>, if any. It gets passed the single value in the JSON |
|
|
429 | object. If it returns a single value, it will be inserted into the data |
|
|
430 | structure. If it returns nothing (not even C<undef> but the empty list), |
|
|
431 | the callback from C<filter_json_object> will be called next, as if no |
|
|
432 | single-key callback were specified. |
|
|
433 | |
|
|
434 | If C<$coderef> is omitted or undefined, the corresponding callback will be |
|
|
435 | disabled. There can only ever be one callback for a given key. |
|
|
436 | |
|
|
437 | As this callback gets called less often then the C<filter_json_object> |
|
|
438 | one, decoding speed will not usually suffer as much. Therefore, single-key |
|
|
439 | objects make excellent targets to serialise Perl objects into, especially |
|
|
440 | as single-key JSON objects are as close to the type-tagged value concept |
|
|
441 | as JSON gets (its basically an ID/VALUE tuple). Of course, JSON does not |
|
|
442 | support this in any way, so you need to make sure your data never looks |
|
|
443 | like a serialised Perl hash. |
|
|
444 | |
|
|
445 | Typical names for the single object key are C<__class_whatever__>, or |
|
|
446 | C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even |
|
|
447 | things like C<__class_md5sum(classname)__>, to reduce the risk of clashing |
|
|
448 | with real hashes. |
|
|
449 | |
|
|
450 | Example, decode JSON objects of the form C<< { "__widget__" => <id> } >> |
|
|
451 | into the corresponding C<< $WIDGET{<id>} >> object: |
|
|
452 | |
|
|
453 | # return whatever is in $WIDGET{5}: |
|
|
454 | JSON::XS |
|
|
455 | ->new |
|
|
456 | ->filter_json_single_key_object (__widget__ => sub { |
|
|
457 | $WIDGET{ $_[0] } |
|
|
458 | }) |
|
|
459 | ->decode ('{"__widget__": 5') |
|
|
460 | |
|
|
461 | # this can be used with a TO_JSON method in some "widget" class |
|
|
462 | # for serialisation to json: |
|
|
463 | sub WidgetBase::TO_JSON { |
|
|
464 | my ($self) = @_; |
|
|
465 | |
|
|
466 | unless ($self->{id}) { |
|
|
467 | $self->{id} = ..get..some..id..; |
|
|
468 | $WIDGET{$self->{id}} = $self; |
|
|
469 | } |
|
|
470 | |
|
|
471 | { __widget__ => $self->{id} } |
|
|
472 | } |
314 | |
473 | |
315 | =item $json = $json->shrink ([$enable]) |
474 | =item $json = $json->shrink ([$enable]) |
316 | |
475 | |
317 | Perl usually over-allocates memory a bit when allocating space for |
476 | Perl usually over-allocates memory a bit when allocating space for |
318 | strings. This flag optionally resizes strings generated by either |
477 | strings. This flag optionally resizes strings generated by either |
… | |
… | |
351 | given character in a string. |
510 | given character in a string. |
352 | |
511 | |
353 | Setting the maximum depth to one disallows any nesting, so that ensures |
512 | Setting the maximum depth to one disallows any nesting, so that ensures |
354 | that the object is only a single hash/object or array. |
513 | that the object is only a single hash/object or array. |
355 | |
514 | |
356 | The argument to C<max_depth> will be rounded up to the next nearest power |
515 | The argument to C<max_depth> will be rounded up to the next highest power |
357 | of two. |
516 | of two. If no argument is given, the highest possible setting will be |
|
|
517 | used, which is rarely useful. |
|
|
518 | |
|
|
519 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
|
|
520 | |
|
|
521 | =item $json = $json->max_size ([$maximum_string_size]) |
|
|
522 | |
|
|
523 | Set the maximum length a JSON text may have (in bytes) where decoding is |
|
|
524 | being attempted. The default is C<0>, meaning no limit. When C<decode> |
|
|
525 | is called on a string longer then this number of characters it will not |
|
|
526 | attempt to decode the string but throw an exception. This setting has no |
|
|
527 | effect on C<encode> (yet). |
|
|
528 | |
|
|
529 | The argument to C<max_size> will be rounded up to the next B<highest> |
|
|
530 | power of two (so may be more than requested). If no argument is given, the |
|
|
531 | limit check will be deactivated (same as when C<0> is specified). |
358 | |
532 | |
359 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
533 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
360 | |
534 | |
361 | =item $json_text = $json->encode ($perl_scalar) |
535 | =item $json_text = $json->encode ($perl_scalar) |
362 | |
536 | |
… | |
… | |
402 | |
576 | |
403 | For the more enlightened: note that in the following descriptions, |
577 | For the more enlightened: note that in the following descriptions, |
404 | lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> |
578 | lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> |
405 | refers to the abstract Perl language itself. |
579 | refers to the abstract Perl language itself. |
406 | |
580 | |
|
|
581 | |
407 | =head2 JSON -> PERL |
582 | =head2 JSON -> PERL |
408 | |
583 | |
409 | =over 4 |
584 | =over 4 |
410 | |
585 | |
411 | =item object |
586 | =item object |
… | |
… | |
423 | are represented by the same codepoints in the Perl string, so no manual |
598 | are represented by the same codepoints in the Perl string, so no manual |
424 | decoding is necessary. |
599 | decoding is necessary. |
425 | |
600 | |
426 | =item number |
601 | =item number |
427 | |
602 | |
428 | A JSON number becomes either an integer or numeric (floating point) |
603 | A JSON number becomes either an integer, numeric (floating point) or |
429 | scalar in perl, depending on its range and any fractional parts. On the |
604 | string scalar in perl, depending on its range and any fractional parts. On |
430 | Perl level, there is no difference between those as Perl handles all the |
605 | the Perl level, there is no difference between those as Perl handles all |
431 | conversion details, but an integer may take slightly less memory and might |
606 | the conversion details, but an integer may take slightly less memory and |
432 | represent more values exactly than (floating point) numbers. |
607 | might represent more values exactly than (floating point) numbers. |
|
|
608 | |
|
|
609 | If the number consists of digits only, JSON::XS will try to represent |
|
|
610 | it as an integer value. If that fails, it will try to represent it as |
|
|
611 | a numeric (floating point) value if that is possible without loss of |
|
|
612 | precision. Otherwise it will preserve the number as a string value. |
|
|
613 | |
|
|
614 | Numbers containing a fractional or exponential part will always be |
|
|
615 | represented as numeric (floating point) values, possibly at a loss of |
|
|
616 | precision. |
|
|
617 | |
|
|
618 | This might create round-tripping problems as numbers might become strings, |
|
|
619 | but as Perl is typeless there is no other way to do it. |
433 | |
620 | |
434 | =item true, false |
621 | =item true, false |
435 | |
622 | |
436 | These JSON atoms become C<0>, C<1>, respectively. Information is lost in |
623 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
437 | this process. Future versions might represent those values differently, |
624 | respectively. They are overloaded to act almost exactly like the numbers |
438 | but they will be guarenteed to act like these integers would normally in |
625 | C<1> and C<0>. You can check wether a scalar is a JSON boolean by using |
439 | Perl. |
626 | the C<JSON::XS::is_bool> function. |
440 | |
627 | |
441 | =item null |
628 | =item null |
442 | |
629 | |
443 | A JSON null atom becomes C<undef> in Perl. |
630 | A JSON null atom becomes C<undef> in Perl. |
444 | |
631 | |
445 | =back |
632 | =back |
|
|
633 | |
446 | |
634 | |
447 | =head2 PERL -> JSON |
635 | =head2 PERL -> JSON |
448 | |
636 | |
449 | The mapping from Perl to JSON is slightly more difficult, as Perl is a |
637 | The mapping from Perl to JSON is slightly more difficult, as Perl is a |
450 | truly typeless language, so we can only guess which JSON type is meant by |
638 | truly typeless language, so we can only guess which JSON type is meant by |
… | |
… | |
475 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
663 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
476 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
664 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
477 | |
665 | |
478 | to_json [\0,JSON::XS::true] # yields [false,true] |
666 | to_json [\0,JSON::XS::true] # yields [false,true] |
479 | |
667 | |
|
|
668 | =item JSON::XS::true, JSON::XS::false |
|
|
669 | |
|
|
670 | These special values become JSON true and JSON false values, |
|
|
671 | respectively. You cna alos use C<\1> and C<\0> directly if you want. |
|
|
672 | |
480 | =item blessed objects |
673 | =item blessed objects |
481 | |
674 | |
482 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
675 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
483 | underlying representation (hash- or arrayref), but this behaviour might |
676 | underlying representation (hash- or arrayref), but this behaviour might |
484 | change in future versions. |
677 | change in future versions. |
… | |
… | |
605 | |
798 | |
606 | Does not check input for validity. |
799 | Does not check input for validity. |
607 | |
800 | |
608 | =back |
801 | =back |
609 | |
802 | |
|
|
803 | |
|
|
804 | =head2 JSON and YAML |
|
|
805 | |
|
|
806 | You often hear that JSON is a subset (or a close subset) of YAML. This is, |
|
|
807 | however, a mass hysteria and very far from the truth. In general, there is |
|
|
808 | no way to configure JSON::XS to output a data structure as valid YAML. |
|
|
809 | |
|
|
810 | If you really must use JSON::XS to generate YAML, you should use this |
|
|
811 | algorithm (subject to change in future versions): |
|
|
812 | |
|
|
813 | my $to_yaml = JSON::XS->new->utf8->space_after (1); |
|
|
814 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
|
|
815 | |
|
|
816 | This will usually generate JSON texts that also parse as valid |
|
|
817 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
|
|
818 | lengths that JSON doesn't have, so you should make sure that your hash |
|
|
819 | keys are noticably shorter than the 1024 characters YAML allows. |
|
|
820 | |
|
|
821 | There might be other incompatibilities that I am not aware of. In general |
|
|
822 | you should not try to generate YAML with a JSON generator or vice versa, |
|
|
823 | or try to parse JSON with a YAML parser or vice versa: chances are high |
|
|
824 | that you will run into severe interoperability problems. |
|
|
825 | |
|
|
826 | |
610 | =head2 SPEED |
827 | =head2 SPEED |
611 | |
828 | |
612 | It seems that JSON::XS is surprisingly fast, as shown in the following |
829 | It seems that JSON::XS is surprisingly fast, as shown in the following |
613 | tables. They have been generated with the help of the C<eg/bench> program |
830 | tables. They have been generated with the help of the C<eg/bench> program |
614 | in the JSON::XS distribution, to make it easy to compare on your own |
831 | in the JSON::XS distribution, to make it easy to compare on your own |
615 | system. |
832 | system. |
616 | |
833 | |
617 | First comes a comparison between various modules using a very short JSON |
834 | First comes a comparison between various modules using a very short |
618 | string: |
835 | single-line JSON string: |
619 | |
836 | |
620 | {"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null} |
837 | {"method": "handleMessage", "params": ["user1", "we were just talking"], \ |
|
|
838 | "id": null, "array":[1,11,234,-5,1e5,1e7, true, false]} |
621 | |
839 | |
622 | It shows the number of encodes/decodes per second (JSON::XS uses the |
840 | It shows the number of encodes/decodes per second (JSON::XS uses |
623 | functional interface, while JSON::XS/2 uses the OO interface with |
841 | the functional interface, while JSON::XS/2 uses the OO interface |
624 | pretty-printing and hashkey sorting enabled). Higher is better: |
842 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
|
|
843 | shrink). Higher is better: |
625 | |
844 | |
|
|
845 | Storable | 15779.925 | 14169.946 | |
|
|
846 | -----------+------------+------------+ |
626 | module | encode | decode | |
847 | module | encode | decode | |
627 | -----------|------------|------------| |
848 | -----------|------------|------------| |
628 | JSON | 11488.516 | 7823.035 | |
849 | JSON | 4990.842 | 4088.813 | |
629 | JSON::DWIW | 94708.054 | 129094.260 | |
850 | JSON::DWIW | 51653.990 | 71575.154 | |
630 | JSON::PC | 63884.157 | 128528.212 | |
851 | JSON::PC | 65948.176 | 74631.744 | |
631 | JSON::Syck | 34898.677 | 42096.911 | |
852 | JSON::PP | 8931.652 | 3817.168 | |
632 | JSON::XS | 654027.064 | 396423.669 | |
853 | JSON::Syck | 24877.248 | 27776.848 | |
633 | JSON::XS/2 | 371564.190 | 371725.613 | |
854 | JSON::XS | 388361.481 | 227951.304 | |
|
|
855 | JSON::XS/2 | 227951.304 | 218453.333 | |
|
|
856 | JSON::XS/3 | 338250.323 | 218453.333 | |
|
|
857 | Storable | 16500.016 | 135300.129 | |
634 | -----------+------------+------------+ |
858 | -----------+------------+------------+ |
635 | |
859 | |
636 | That is, JSON::XS is more than six times faster than JSON::DWIW on |
860 | That is, JSON::XS is about five times faster than JSON::DWIW on encoding, |
637 | encoding, more than three times faster on decoding, and about thirty times |
861 | about three times faster on decoding, and over fourty times faster |
638 | faster than JSON, even with pretty-printing and key sorting. |
862 | than JSON, even with pretty-printing and key sorting. It also compares |
|
|
863 | favourably to Storable for small amounts of data. |
639 | |
864 | |
640 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
865 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
641 | search API (http://nanoref.com/yahooapis/mgPdGg): |
866 | search API (http://nanoref.com/yahooapis/mgPdGg): |
642 | |
867 | |
643 | module | encode | decode | |
868 | module | encode | decode | |
644 | -----------|------------|------------| |
869 | -----------|------------|------------| |
645 | JSON | 273.023 | 44.674 | |
870 | JSON | 55.260 | 34.971 | |
646 | JSON::DWIW | 1089.383 | 1145.704 | |
871 | JSON::DWIW | 825.228 | 1082.513 | |
647 | JSON::PC | 3097.419 | 2393.921 | |
872 | JSON::PC | 3571.444 | 2394.829 | |
648 | JSON::Syck | 514.060 | 843.053 | |
873 | JSON::PP | 210.987 | 32.574 | |
649 | JSON::XS | 6479.668 | 3636.364 | |
874 | JSON::Syck | 552.551 | 787.544 | |
650 | JSON::XS/2 | 3774.221 | 3599.124 | |
875 | JSON::XS | 5780.463 | 4854.519 | |
|
|
876 | JSON::XS/2 | 3869.998 | 4798.975 | |
|
|
877 | JSON::XS/3 | 5862.880 | 4798.975 | |
|
|
878 | Storable | 4445.002 | 5235.027 | |
651 | -----------+------------+------------+ |
879 | -----------+------------+------------+ |
652 | |
880 | |
653 | Again, JSON::XS leads by far. |
881 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
|
|
882 | decodes faster). |
654 | |
883 | |
655 | On large strings containing lots of high unicode characters, some modules |
884 | On large strings containing lots of high unicode characters, some modules |
656 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
885 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
657 | will be broken due to missing (or wrong) unicode handling. Others refuse |
886 | will be broken due to missing (or wrong) unicode handling. Others refuse |
658 | to decode or encode properly, so it was impossible to prepare a fair |
887 | to decode or encode properly, so it was impossible to prepare a fair |
… | |
… | |
671 | Second, you need to avoid resource-starving attacks. That means you should |
900 | Second, you need to avoid resource-starving attacks. That means you should |
672 | limit the size of JSON texts you accept, or make sure then when your |
901 | limit the size of JSON texts you accept, or make sure then when your |
673 | resources run out, thats just fine (e.g. by using a separate process that |
902 | resources run out, thats just fine (e.g. by using a separate process that |
674 | can crash safely). The size of a JSON text in octets or characters is |
903 | can crash safely). The size of a JSON text in octets or characters is |
675 | usually a good indication of the size of the resources required to decode |
904 | usually a good indication of the size of the resources required to decode |
676 | it into a Perl structure. |
905 | it into a Perl structure. While JSON::XS can check the size of the JSON |
|
|
906 | text, it might be too late when you already have it in memory, so you |
|
|
907 | might want to check the size before you accept the string. |
677 | |
908 | |
678 | Third, JSON::XS recurses using the C stack when decoding objects and |
909 | Third, JSON::XS recurses using the C stack when decoding objects and |
679 | arrays. The C stack is a limited resource: for instance, on my amd64 |
910 | arrays. The C stack is a limited resource: for instance, on my amd64 |
680 | machine with 8MB of stack size I can decode around 180k nested arrays but |
911 | machine with 8MB of stack size I can decode around 180k nested arrays but |
681 | only 14k nested JSON objects (due to perl itself recursing deeply on croak |
912 | only 14k nested JSON objects (due to perl itself recursing deeply on croak |
… | |
… | |
686 | |
917 | |
687 | And last but least, something else could bomb you that I forgot to think |
918 | And last but least, something else could bomb you that I forgot to think |
688 | of. In that case, you get to keep the pieces. I am always open for hints, |
919 | of. In that case, you get to keep the pieces. I am always open for hints, |
689 | though... |
920 | though... |
690 | |
921 | |
|
|
922 | If you are using JSON::XS to return packets to consumption |
|
|
923 | by javascript scripts in a browser you should have a look at |
|
|
924 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see wether |
|
|
925 | you are vulnerable to some common attack vectors (which really are browser |
|
|
926 | design bugs, but it is still you who will have to deal with it, as major |
|
|
927 | browser developers care only for features, not about doing security |
|
|
928 | right). |
|
|
929 | |
691 | |
930 | |
692 | =head1 BUGS |
931 | =head1 BUGS |
693 | |
932 | |
694 | While the goal of this module is to be correct, that unfortunately does |
933 | While the goal of this module is to be correct, that unfortunately does |
695 | not mean its bug-free, only that I think its design is bug-free. It is |
934 | not mean its bug-free, only that I think its design is bug-free. It is |
696 | still relatively early in its development. If you keep reporting bugs they |
935 | still relatively early in its development. If you keep reporting bugs they |
697 | will be fixed swiftly, though. |
936 | will be fixed swiftly, though. |
698 | |
937 | |
699 | =cut |
938 | =cut |
700 | |
939 | |
|
|
940 | our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; |
|
|
941 | our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; |
|
|
942 | |
701 | sub true() { \1 } |
943 | sub true() { $true } |
702 | sub false() { \0 } |
944 | sub false() { $false } |
|
|
945 | |
|
|
946 | sub is_bool($) { |
|
|
947 | UNIVERSAL::isa $_[0], "JSON::XS::Boolean" |
|
|
948 | # or UNIVERSAL::isa $_[0], "JSON::Literal" |
|
|
949 | } |
|
|
950 | |
|
|
951 | XSLoader::load "JSON::XS", $VERSION; |
|
|
952 | |
|
|
953 | package JSON::XS::Boolean; |
|
|
954 | |
|
|
955 | use overload |
|
|
956 | "0+" => sub { ${$_[0]} }, |
|
|
957 | "++" => sub { $_[0] = ${$_[0]} + 1 }, |
|
|
958 | "--" => sub { $_[0] = ${$_[0]} - 1 }, |
|
|
959 | fallback => 1; |
703 | |
960 | |
704 | 1; |
961 | 1; |
705 | |
962 | |
706 | =head1 AUTHOR |
963 | =head1 AUTHOR |
707 | |
964 | |