… | |
… | |
85 | |
85 | |
86 | package JSON::XS; |
86 | package JSON::XS; |
87 | |
87 | |
88 | use strict; |
88 | use strict; |
89 | |
89 | |
90 | BEGIN { |
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91 | our $VERSION = '1.11'; |
90 | our $VERSION = '1.4'; |
92 | our @ISA = qw(Exporter); |
91 | our @ISA = qw(Exporter); |
93 | |
92 | |
94 | our @EXPORT = qw(to_json from_json objToJson jsonToObj); |
93 | our @EXPORT = qw(to_json from_json objToJson jsonToObj); |
95 | require Exporter; |
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|
96 | |
94 | |
97 | require XSLoader; |
95 | use Exporter; |
98 | XSLoader::load JSON::XS::, $VERSION; |
96 | use XSLoader; |
99 | } |
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|
100 | |
97 | |
101 | =head1 FUNCTIONAL INTERFACE |
98 | =head1 FUNCTIONAL INTERFACE |
102 | |
99 | |
103 | The following convinience methods are provided by this module. They are |
100 | The following convinience methods are provided by this module. They are |
104 | exported by default: |
101 | exported by default: |
… | |
… | |
126 | This function call is functionally identical to: |
123 | This 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 | |
130 | except being faster. |
127 | except being faster. |
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128 | |
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129 | =item $is_boolean = JSON::XS::is_bool $scalar |
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130 | |
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131 | Returns true if the passed scalar represents either JSON::XS::true or |
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132 | JSON::XS::false, two constants that act like C<1> and C<0>, respectively |
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133 | and are used to represent JSON C<true> and C<false> values in Perl. |
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134 | |
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135 | See MAPPING, below, for more information on how JSON values are mapped to |
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136 | Perl. |
131 | |
137 | |
132 | =back |
138 | =back |
133 | |
139 | |
134 | |
140 | |
135 | =head1 OBJECT-ORIENTED INTERFACE |
141 | =head1 OBJECT-ORIENTED INTERFACE |
… | |
… | |
154 | |
160 | |
155 | If C<$enable> is true (or missing), then the C<encode> method will not |
161 | If C<$enable> is true (or missing), then the C<encode> method will not |
156 | generate characters outside the code range C<0..127> (which is ASCII). Any |
162 | generate characters outside the code range C<0..127> (which is ASCII). Any |
157 | unicode characters outside that range will be escaped using either a |
163 | unicode characters outside that range will be escaped using either a |
158 | single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, |
164 | single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, |
159 | as per RFC4627. |
165 | as per RFC4627. The resulting encoded JSON text can be treated as a native |
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166 | unicode string, an ascii-encoded, latin1-encoded or UTF-8 encoded string, |
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167 | or any other superset of ASCII. |
160 | |
168 | |
161 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
169 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
162 | characters unless required by the JSON syntax. This results in a faster |
170 | characters unless required by the JSON syntax or other flags. This results |
163 | and more compact format. |
171 | in a faster and more compact format. |
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172 | |
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173 | The main use for this flag is to produce JSON texts that can be |
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174 | transmitted over a 7-bit channel, as the encoded JSON texts will not |
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175 | contain any 8 bit characters. |
164 | |
176 | |
165 | JSON::XS->new->ascii (1)->encode ([chr 0x10401]) |
177 | JSON::XS->new->ascii (1)->encode ([chr 0x10401]) |
166 | => ["\ud801\udc01"] |
178 | => ["\ud801\udc01"] |
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179 | |
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180 | =item $json = $json->latin1 ([$enable]) |
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181 | |
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182 | If C<$enable> is true (or missing), then the C<encode> method will encode |
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183 | the resulting JSON text as latin1 (or iso-8859-1), escaping any characters |
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184 | outside the code range C<0..255>. The resulting string can be treated as a |
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185 | latin1-encoded JSON text or a native unicode string. The C<decode> method |
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186 | will not be affected in any way by this flag, as C<decode> by default |
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187 | expects unicode, which is a strict superset of latin1. |
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188 | |
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189 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
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190 | characters unless required by the JSON syntax or other flags. |
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191 | |
|
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192 | The main use for this flag is efficiently encoding binary data as JSON |
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193 | text, as most octets will not be escaped, resulting in a smaller encoded |
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194 | size. The disadvantage is that the resulting JSON text is encoded |
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195 | in latin1 (and must correctly be treated as such when storing and |
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196 | transfering), a rare encoding for JSON. It is therefore most useful when |
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197 | you want to store data structures known to contain binary data efficiently |
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198 | in files or databases, not when talking to other JSON encoders/decoders. |
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199 | |
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200 | JSON::XS->new->latin1->encode (["\x{89}\x{abc}"] |
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201 | => ["\x{89}\\u0abc"] # (perl syntax, U+abc escaped, U+89 not) |
167 | |
202 | |
168 | =item $json = $json->utf8 ([$enable]) |
203 | =item $json = $json->utf8 ([$enable]) |
169 | |
204 | |
170 | If C<$enable> is true (or missing), then the C<encode> method will encode |
205 | If C<$enable> is true (or missing), then the C<encode> method will encode |
171 | the JSON result into UTF-8, as required by many protocols, while the |
206 | the JSON result into UTF-8, as required by many protocols, while the |
… | |
… | |
280 | Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>, |
315 | Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>, |
281 | resulting in an invalid JSON text: |
316 | resulting in an invalid JSON text: |
282 | |
317 | |
283 | JSON::XS->new->allow_nonref->encode ("Hello, World!") |
318 | JSON::XS->new->allow_nonref->encode ("Hello, World!") |
284 | => "Hello, World!" |
319 | => "Hello, World!" |
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320 | |
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321 | =item $json = $json->allow_blessed ([$enable]) |
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322 | |
|
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323 | If C<$enable> is true (or missing), then the C<encode> method will not |
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324 | barf when it encounters a blessed reference. Instead, the value of the |
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325 | B<convert_blessed> option will decide wether C<null> (C<convert_blessed> |
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326 | disabled or no C<to_json> method found) or a representation of the |
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327 | object (C<convert_blessed> enabled and C<to_json> method found) is being |
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328 | encoded. Has no effect on C<decode>. |
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329 | |
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330 | If C<$enable> is false (the default), then C<encode> will throw an |
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331 | exception when it encounters a blessed object. |
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332 | |
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333 | =item $json = $json->convert_blessed ([$enable]) |
|
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334 | |
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335 | If C<$enable> is true (or missing), then C<encode>, upon encountering a |
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336 | blessed object, will check for the availability of the C<TO_JSON> method |
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337 | on the object's class. If found, it will be called in scalar context |
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338 | and the resulting scalar will be encoded instead of the object. If no |
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339 | C<TO_JSON> method is found, the value of C<allow_blessed> will decide what |
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340 | to do. |
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341 | |
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342 | The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON> |
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343 | returns other blessed objects, those will be handled in the same |
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344 | way. C<TO_JSON> must take care of not causing an endless recursion cycle |
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345 | (== crash) in this case. The name of C<TO_JSON> was chosen because other |
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346 | methods called by the Perl core (== not the user of the object) are |
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347 | usually in upper case letters and to avoid collisions with the C<to_json> |
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348 | function. |
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349 | |
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350 | If C<$enable> is false, then the C<allow_blessed> setting will decide what |
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351 | to do when a blessed object is found. |
285 | |
352 | |
286 | =item $json = $json->shrink ([$enable]) |
353 | =item $json = $json->shrink ([$enable]) |
287 | |
354 | |
288 | Perl usually over-allocates memory a bit when allocating space for |
355 | Perl usually over-allocates memory a bit when allocating space for |
289 | strings. This flag optionally resizes strings generated by either |
356 | strings. This flag optionally resizes strings generated by either |
… | |
… | |
345 | |
412 | |
346 | JSON numbers and strings become simple Perl scalars. JSON arrays become |
413 | JSON numbers and strings become simple Perl scalars. JSON arrays become |
347 | Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes |
414 | Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes |
348 | C<1>, C<false> becomes C<0> and C<null> becomes C<undef>. |
415 | C<1>, C<false> becomes C<0> and C<null> becomes C<undef>. |
349 | |
416 | |
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417 | =item ($perl_scalar, $characters) = $json->decode_prefix ($json_text) |
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418 | |
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419 | This works like the C<decode> method, but instead of raising an exception |
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420 | when there is trailing garbage after the first JSON object, it will |
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421 | silently stop parsing there and return the number of characters consumed |
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422 | so far. |
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423 | |
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424 | This is useful if your JSON texts are not delimited by an outer protocol |
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425 | (which is not the brightest thing to do in the first place) and you need |
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426 | to know where the JSON text ends. |
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427 | |
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428 | JSON::XS->new->decode_prefix ("[1] the tail") |
|
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429 | => ([], 3) |
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430 | |
350 | =back |
431 | =back |
351 | |
432 | |
352 | |
433 | |
353 | =head1 MAPPING |
434 | =head1 MAPPING |
354 | |
435 | |
… | |
… | |
358 | (what you put in comes out as something equivalent). |
439 | (what you put in comes out as something equivalent). |
359 | |
440 | |
360 | For the more enlightened: note that in the following descriptions, |
441 | For the more enlightened: note that in the following descriptions, |
361 | lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> |
442 | lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> |
362 | refers to the abstract Perl language itself. |
443 | refers to the abstract Perl language itself. |
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444 | |
363 | |
445 | |
364 | =head2 JSON -> PERL |
446 | =head2 JSON -> PERL |
365 | |
447 | |
366 | =over 4 |
448 | =over 4 |
367 | |
449 | |
… | |
… | |
388 | conversion details, but an integer may take slightly less memory and might |
470 | conversion details, but an integer may take slightly less memory and might |
389 | represent more values exactly than (floating point) numbers. |
471 | represent more values exactly than (floating point) numbers. |
390 | |
472 | |
391 | =item true, false |
473 | =item true, false |
392 | |
474 | |
393 | These JSON atoms become C<0>, C<1>, respectively. Information is lost in |
475 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
394 | this process. Future versions might represent those values differently, |
476 | respectively. They are overloaded to act almost exactly like the numbers |
395 | but they will be guarenteed to act like these integers would normally in |
477 | C<1> and C<0>. You can check wether a scalar is a JSON boolean by using |
396 | Perl. |
478 | the C<JSON::XS::is_bool> function. |
397 | |
479 | |
398 | =item null |
480 | =item null |
399 | |
481 | |
400 | A JSON null atom becomes C<undef> in Perl. |
482 | A JSON null atom becomes C<undef> in Perl. |
401 | |
483 | |
402 | =back |
484 | =back |
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|
485 | |
403 | |
486 | |
404 | =head2 PERL -> JSON |
487 | =head2 PERL -> JSON |
405 | |
488 | |
406 | The mapping from Perl to JSON is slightly more difficult, as Perl is a |
489 | The mapping from Perl to JSON is slightly more difficult, as Perl is a |
407 | truly typeless language, so we can only guess which JSON type is meant by |
490 | truly typeless language, so we can only guess which JSON type is meant by |
… | |
… | |
432 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
515 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
433 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
516 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
434 | |
517 | |
435 | to_json [\0,JSON::XS::true] # yields [false,true] |
518 | to_json [\0,JSON::XS::true] # yields [false,true] |
436 | |
519 | |
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520 | =item JSON::XS::true, JSON::XS::false |
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521 | |
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522 | These special values become JSON true and JSON false values, |
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523 | respectively. You cna alos use C<\1> and C<\0> directly if you want. |
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524 | |
437 | =item blessed objects |
525 | =item blessed objects |
438 | |
526 | |
439 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
527 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
440 | underlying representation (hash- or arrayref), but this behaviour might |
528 | underlying representation (hash- or arrayref), but this behaviour might |
441 | change in future versions. |
529 | change in future versions. |
… | |
… | |
562 | |
650 | |
563 | Does not check input for validity. |
651 | Does not check input for validity. |
564 | |
652 | |
565 | =back |
653 | =back |
566 | |
654 | |
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655 | |
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656 | =head2 JSON and YAML |
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657 | |
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658 | You often hear that JSON is a subset (or a close subset) of YAML. This is, |
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659 | however, a mass hysteria and very far from the truth. In general, there is |
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660 | no way to configure JSON::XS to output a data structure as valid YAML. |
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661 | |
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662 | If you really must use JSON::XS to generate YAML, you should use this |
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663 | algorithm (subject to change in future versions): |
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664 | |
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665 | my $to_yaml = JSON::XS->new->utf8->space_after (1); |
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666 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
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667 | |
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668 | This will usually generate JSON texts that also parse as valid |
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669 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
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670 | lengths that JSON doesn't have, so you should make sure that your hash |
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671 | keys are noticably shorter than the 1024 characters YAML allows. |
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672 | |
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673 | There might be other incompatibilities that I am not aware of. In general |
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674 | you should not try to generate YAML with a JSON generator or vice versa, |
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675 | or try to parse JSON with a YAML parser or vice versa: chances are high |
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676 | that you will run into severe interoperability problems. |
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677 | |
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678 | |
567 | =head2 SPEED |
679 | =head2 SPEED |
568 | |
680 | |
569 | It seems that JSON::XS is surprisingly fast, as shown in the following |
681 | It seems that JSON::XS is surprisingly fast, as shown in the following |
570 | tables. They have been generated with the help of the C<eg/bench> program |
682 | tables. They have been generated with the help of the C<eg/bench> program |
571 | in the JSON::XS distribution, to make it easy to compare on your own |
683 | in the JSON::XS distribution, to make it easy to compare on your own |
572 | system. |
684 | system. |
573 | |
685 | |
574 | First comes a comparison between various modules using a very short JSON |
686 | First comes a comparison between various modules using a very short |
575 | string: |
687 | single-line JSON string: |
576 | |
688 | |
577 | {"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null} |
689 | {"method": "handleMessage", "params": ["user1", "we were just talking"], \ |
|
|
690 | "id": null, "array":[1,11,234,-5,1e5,1e7, true, false]} |
578 | |
691 | |
579 | It shows the number of encodes/decodes per second (JSON::XS uses the |
692 | It shows the number of encodes/decodes per second (JSON::XS uses |
580 | functional interface, while JSON::XS/2 uses the OO interface with |
693 | the functional interface, while JSON::XS/2 uses the OO interface |
581 | pretty-printing and hashkey sorting enabled). Higher is better: |
694 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
|
|
695 | shrink). Higher is better: |
582 | |
696 | |
583 | module | encode | decode | |
697 | module | encode | decode | |
584 | -----------|------------|------------| |
698 | -----------|------------|------------| |
585 | JSON | 11488.516 | 7823.035 | |
699 | JSON | 7645.468 | 4208.613 | |
586 | JSON::DWIW | 94708.054 | 129094.260 | |
700 | JSON::DWIW | 40721.398 | 77101.176 | |
587 | JSON::PC | 63884.157 | 128528.212 | |
701 | JSON::PC | 65948.176 | 78251.940 | |
588 | JSON::Syck | 34898.677 | 42096.911 | |
702 | JSON::Syck | 22844.793 | 26479.192 | |
589 | JSON::XS | 654027.064 | 396423.669 | |
703 | JSON::XS | 388361.481 | 199728.762 | |
590 | JSON::XS/2 | 371564.190 | 371725.613 | |
704 | JSON::XS/2 | 218453.333 | 192399.266 | |
|
|
705 | JSON::XS/3 | 338250.323 | 192399.266 | |
|
|
706 | Storable | 15779.925 | 14169.946 | |
591 | -----------+------------+------------+ |
707 | -----------+------------+------------+ |
592 | |
708 | |
593 | That is, JSON::XS is more than six times faster than JSON::DWIW on |
709 | That is, JSON::XS is about five times faster than JSON::DWIW on encoding, |
594 | encoding, more than three times faster on decoding, and about thirty times |
710 | about three times faster on decoding, and over fourty times faster |
595 | faster than JSON, even with pretty-printing and key sorting. |
711 | than JSON, even with pretty-printing and key sorting. It also compares |
|
|
712 | favourably to Storable for small amounts of data. |
596 | |
713 | |
597 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
714 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
598 | search API (http://nanoref.com/yahooapis/mgPdGg): |
715 | search API (http://nanoref.com/yahooapis/mgPdGg): |
599 | |
716 | |
600 | module | encode | decode | |
717 | module | encode | decode | |
601 | -----------|------------|------------| |
718 | -----------|------------|------------| |
602 | JSON | 273.023 | 44.674 | |
719 | JSON | 254.685 | 37.665 | |
603 | JSON::DWIW | 1089.383 | 1145.704 | |
720 | JSON::DWIW | 843.343 | 1049.731 | |
604 | JSON::PC | 3097.419 | 2393.921 | |
721 | JSON::PC | 3602.116 | 2307.352 | |
605 | JSON::Syck | 514.060 | 843.053 | |
722 | JSON::Syck | 505.107 | 787.899 | |
606 | JSON::XS | 6479.668 | 3636.364 | |
723 | JSON::XS | 5747.196 | 3690.220 | |
607 | JSON::XS/2 | 3774.221 | 3599.124 | |
724 | JSON::XS/2 | 3968.121 | 3676.634 | |
|
|
725 | JSON::XS/3 | 6105.246 | 3662.508 | |
|
|
726 | Storable | 4417.337 | 5285.161 | |
608 | -----------+------------+------------+ |
727 | -----------+------------+------------+ |
609 | |
728 | |
610 | Again, JSON::XS leads by far. |
729 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
|
|
730 | decodes faster). |
611 | |
731 | |
612 | On large strings containing lots of high unicode characters, some modules |
732 | On large strings containing lots of high unicode characters, some modules |
613 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
733 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
614 | will be broken due to missing (or wrong) unicode handling. Others refuse |
734 | will be broken due to missing (or wrong) unicode handling. Others refuse |
615 | to decode or encode properly, so it was impossible to prepare a fair |
735 | to decode or encode properly, so it was impossible to prepare a fair |
… | |
… | |
643 | |
763 | |
644 | And last but least, something else could bomb you that I forgot to think |
764 | And last but least, something else could bomb you that I forgot to think |
645 | of. In that case, you get to keep the pieces. I am always open for hints, |
765 | of. In that case, you get to keep the pieces. I am always open for hints, |
646 | though... |
766 | though... |
647 | |
767 | |
|
|
768 | If you are using JSON::XS to return packets to consumption |
|
|
769 | by javascript scripts in a browser you should have a look at |
|
|
770 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see wether |
|
|
771 | you are vulnerable to some common attack vectors (which really are browser |
|
|
772 | design bugs, but it is still you who will have to deal with it, as major |
|
|
773 | browser developers care only for features, not about doing security |
|
|
774 | right). |
|
|
775 | |
648 | |
776 | |
649 | =head1 BUGS |
777 | =head1 BUGS |
650 | |
778 | |
651 | While the goal of this module is to be correct, that unfortunately does |
779 | While the goal of this module is to be correct, that unfortunately does |
652 | not mean its bug-free, only that I think its design is bug-free. It is |
780 | not mean its bug-free, only that I think its design is bug-free. It is |
653 | still relatively early in its development. If you keep reporting bugs they |
781 | still relatively early in its development. If you keep reporting bugs they |
654 | will be fixed swiftly, though. |
782 | will be fixed swiftly, though. |
655 | |
783 | |
656 | =cut |
784 | =cut |
657 | |
785 | |
|
|
786 | our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; |
|
|
787 | our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; |
|
|
788 | |
658 | sub true() { \1 } |
789 | sub true() { $true } |
659 | sub false() { \0 } |
790 | sub false() { $false } |
|
|
791 | |
|
|
792 | sub is_bool($) { |
|
|
793 | UNIVERSAL::isa $_[0], "JSON::XS::Boolean" |
|
|
794 | # or UNIVERSAL::isa $_[0], "JSON::Literal" |
|
|
795 | } |
|
|
796 | |
|
|
797 | XSLoader::load "JSON::XS", $VERSION; |
|
|
798 | |
|
|
799 | package JSON::XS::Boolean; |
|
|
800 | |
|
|
801 | use overload |
|
|
802 | "0+" => sub { ${$_[0]} }, |
|
|
803 | "++" => sub { $_[0] = ${$_[0]} + 1 }, |
|
|
804 | "--" => sub { $_[0] = ${$_[0]} - 1 }, |
|
|
805 | fallback => 1; |
660 | |
806 | |
661 | 1; |
807 | 1; |
662 | |
808 | |
663 | =head1 AUTHOR |
809 | =head1 AUTHOR |
664 | |
810 | |