… | |
… | |
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 = '0.8'; |
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; |
|
|
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 |
… | |
… | |
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!" |
285 | |
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 by 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 | This setting does not yet influence C<decode> in any way, but in the |
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351 | future, global hooks might get installed that influence C<decode> and are |
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352 | enabled by this setting. |
|
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353 | |
|
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354 | If C<$enable> is false, then the C<allow_blessed> setting will decide what |
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355 | to do when a blessed object is found. |
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356 | |
286 | =item $json = $json->shrink ([$enable]) |
357 | =item $json = $json->shrink ([$enable]) |
287 | |
358 | |
288 | Perl usually over-allocates memory a bit when allocating space for |
359 | Perl usually over-allocates memory a bit when allocating space for |
289 | strings. This flag optionally resizes strings generated by either |
360 | strings. This flag optionally resizes strings generated by either |
290 | C<encode> or C<decode> to their minimum size possible. This can save |
361 | C<encode> or C<decode> to their minimum size possible. This can save |
291 | memory when your JSON texts are either very very long or you have many |
362 | memory when your JSON texts are either very very long or you have many |
292 | short strings. It will also try to downgrade any strings to octet-form |
363 | short strings. It will also try to downgrade any strings to octet-form |
293 | if possible: perl stores strings internally either in an encoding called |
364 | if possible: perl stores strings internally either in an encoding called |
294 | UTF-X or in octet-form. The latter cannot store everything but uses less |
365 | UTF-X or in octet-form. The latter cannot store everything but uses less |
295 | space in general. |
366 | space in general (and some buggy Perl or C code might even rely on that |
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367 | internal representation being used). |
296 | |
368 | |
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369 | The actual definition of what shrink does might change in future versions, |
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370 | but it will always try to save space at the expense of time. |
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371 | |
297 | If C<$enable> is true (or missing), the string returned by C<encode> will be shrunk-to-fit, |
372 | If C<$enable> is true (or missing), the string returned by C<encode> will |
298 | while all strings generated by C<decode> will also be shrunk-to-fit. |
373 | be shrunk-to-fit, while all strings generated by C<decode> will also be |
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374 | shrunk-to-fit. |
299 | |
375 | |
300 | If C<$enable> is false, then the normal perl allocation algorithms are used. |
376 | If C<$enable> is false, then the normal perl allocation algorithms are used. |
301 | If you work with your data, then this is likely to be faster. |
377 | If you work with your data, then this is likely to be faster. |
302 | |
378 | |
303 | In the future, this setting might control other things, such as converting |
379 | In the future, this setting might control other things, such as converting |
304 | strings that look like integers or floats into integers or floats |
380 | strings that look like integers or floats into integers or floats |
305 | internally (there is no difference on the Perl level), saving space. |
381 | internally (there is no difference on the Perl level), saving space. |
306 | |
382 | |
307 | =item $json = $json->max_depth ([$maximum_nesting_depth]) |
383 | =item $json = $json->max_depth ([$maximum_nesting_depth]) |
308 | |
384 | |
309 | Sets the maximum nesting level (default C<8192>) accepted while encoding |
385 | Sets the maximum nesting level (default C<512>) accepted while encoding |
310 | or decoding. If the JSON text or Perl data structure has an equal or |
386 | or decoding. If the JSON text or Perl data structure has an equal or |
311 | higher nesting level then this limit, then the encoder and decoder will |
387 | higher nesting level then this limit, then the encoder and decoder will |
312 | stop and croak at that point. |
388 | stop and croak at that point. |
313 | |
389 | |
314 | Nesting level is defined by number of hash- or arrayrefs that the encoder |
390 | Nesting level is defined by number of hash- or arrayrefs that the encoder |
… | |
… | |
340 | |
416 | |
341 | JSON numbers and strings become simple Perl scalars. JSON arrays become |
417 | JSON numbers and strings become simple Perl scalars. JSON arrays become |
342 | Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes |
418 | Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes |
343 | C<1>, C<false> becomes C<0> and C<null> becomes C<undef>. |
419 | C<1>, C<false> becomes C<0> and C<null> becomes C<undef>. |
344 | |
420 | |
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421 | =item ($perl_scalar, $characters) = $json->decode_prefix ($json_text) |
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422 | |
|
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423 | This works like the C<decode> method, but instead of raising an exception |
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424 | when there is trailing garbage after the first JSON object, it will |
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425 | silently stop parsing there and return the number of characters consumed |
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426 | so far. |
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427 | |
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428 | This is useful if your JSON texts are not delimited by an outer protocol |
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429 | (which is not the brightest thing to do in the first place) and you need |
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430 | to know where the JSON text ends. |
|
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431 | |
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432 | JSON::XS->new->decode_prefix ("[1] the tail") |
|
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433 | => ([], 3) |
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434 | |
345 | =back |
435 | =back |
346 | |
436 | |
347 | |
437 | |
348 | =head1 MAPPING |
438 | =head1 MAPPING |
349 | |
439 | |
… | |
… | |
353 | (what you put in comes out as something equivalent). |
443 | (what you put in comes out as something equivalent). |
354 | |
444 | |
355 | For the more enlightened: note that in the following descriptions, |
445 | For the more enlightened: note that in the following descriptions, |
356 | lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> |
446 | lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> |
357 | refers to the abstract Perl language itself. |
447 | refers to the abstract Perl language itself. |
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448 | |
358 | |
449 | |
359 | =head2 JSON -> PERL |
450 | =head2 JSON -> PERL |
360 | |
451 | |
361 | =over 4 |
452 | =over 4 |
362 | |
453 | |
… | |
… | |
383 | conversion details, but an integer may take slightly less memory and might |
474 | conversion details, but an integer may take slightly less memory and might |
384 | represent more values exactly than (floating point) numbers. |
475 | represent more values exactly than (floating point) numbers. |
385 | |
476 | |
386 | =item true, false |
477 | =item true, false |
387 | |
478 | |
388 | These JSON atoms become C<0>, C<1>, respectively. Information is lost in |
479 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
389 | this process. Future versions might represent those values differently, |
480 | respectively. They are overloaded to act almost exactly like the numbers |
390 | but they will be guarenteed to act like these integers would normally in |
481 | C<1> and C<0>. You can check wether a scalar is a JSON boolean by using |
391 | Perl. |
482 | the C<JSON::XS::is_bool> function. |
392 | |
483 | |
393 | =item null |
484 | =item null |
394 | |
485 | |
395 | A JSON null atom becomes C<undef> in Perl. |
486 | A JSON null atom becomes C<undef> in Perl. |
396 | |
487 | |
397 | =back |
488 | =back |
|
|
489 | |
398 | |
490 | |
399 | =head2 PERL -> JSON |
491 | =head2 PERL -> JSON |
400 | |
492 | |
401 | The mapping from Perl to JSON is slightly more difficult, as Perl is a |
493 | The mapping from Perl to JSON is slightly more difficult, as Perl is a |
402 | truly typeless language, so we can only guess which JSON type is meant by |
494 | truly typeless language, so we can only guess which JSON type is meant by |
… | |
… | |
405 | =over 4 |
497 | =over 4 |
406 | |
498 | |
407 | =item hash references |
499 | =item hash references |
408 | |
500 | |
409 | Perl hash references become JSON objects. As there is no inherent ordering |
501 | Perl hash references become JSON objects. As there is no inherent ordering |
410 | in hash keys, they will usually be encoded in a pseudo-random order that |
502 | in hash keys (or JSON objects), they will usually be encoded in a |
411 | can change between runs of the same program but stays generally the same |
503 | pseudo-random order that can change between runs of the same program but |
412 | within a single run of a program. JSON::XS can optionally sort the hash |
504 | stays generally the same within a single run of a program. JSON::XS can |
413 | keys (determined by the I<canonical> flag), so the same datastructure |
505 | optionally sort the hash keys (determined by the I<canonical> flag), so |
414 | will serialise to the same JSON text (given same settings and version of |
506 | the same datastructure will serialise to the same JSON text (given same |
415 | JSON::XS), but this incurs a runtime overhead. |
507 | settings and version of JSON::XS), but this incurs a runtime overhead |
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508 | and is only rarely useful, e.g. when you want to compare some JSON text |
|
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509 | against another for equality. |
416 | |
510 | |
417 | =item array references |
511 | =item array references |
418 | |
512 | |
419 | Perl array references become JSON arrays. |
513 | Perl array references become JSON arrays. |
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514 | |
|
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515 | =item other references |
|
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516 | |
|
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517 | Other unblessed references are generally not allowed and will cause an |
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518 | exception to be thrown, except for references to the integers C<0> and |
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519 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
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520 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
|
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521 | |
|
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522 | to_json [\0,JSON::XS::true] # yields [false,true] |
|
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523 | |
|
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524 | =item JSON::XS::true, JSON::XS::false |
|
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525 | |
|
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526 | These special values become JSON true and JSON false values, |
|
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527 | respectively. You cna alos use C<\1> and C<\0> directly if you want. |
420 | |
528 | |
421 | =item blessed objects |
529 | =item blessed objects |
422 | |
530 | |
423 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
531 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
424 | underlying representation (hash- or arrayref), but this behaviour might |
532 | underlying representation (hash- or arrayref), but this behaviour might |
… | |
… | |
456 | $x += 0; # numify it, ensuring it will be dumped as a number |
564 | $x += 0; # numify it, ensuring it will be dumped as a number |
457 | $x *= 1; # same thing, the choise is yours. |
565 | $x *= 1; # same thing, the choise is yours. |
458 | |
566 | |
459 | You can not currently output JSON booleans or force the type in other, |
567 | You can not currently output JSON booleans or force the type in other, |
460 | less obscure, ways. Tell me if you need this capability. |
568 | less obscure, ways. Tell me if you need this capability. |
461 | |
|
|
462 | =item circular data structures |
|
|
463 | |
|
|
464 | Those will be encoded until memory or stackspace runs out. |
|
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465 | |
569 | |
466 | =back |
570 | =back |
467 | |
571 | |
468 | |
572 | |
469 | =head1 COMPARISON |
573 | =head1 COMPARISON |
… | |
… | |
550 | |
654 | |
551 | Does not check input for validity. |
655 | Does not check input for validity. |
552 | |
656 | |
553 | =back |
657 | =back |
554 | |
658 | |
|
|
659 | |
|
|
660 | =head2 JSON and YAML |
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661 | |
|
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662 | You often hear that JSON is a subset (or a close subset) of YAML. This is, |
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663 | however, a mass hysteria and very far from the truth. In general, there is |
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664 | no way to configure JSON::XS to output a data structure as valid YAML. |
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665 | |
|
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666 | If you really must use JSON::XS to generate YAML, you should use this |
|
|
667 | algorithm (subject to change in future versions): |
|
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668 | |
|
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669 | my $to_yaml = JSON::XS->new->utf8->space_after (1); |
|
|
670 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
|
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671 | |
|
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672 | This will usually generate JSON texts that also parse as valid |
|
|
673 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
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|
674 | lengths that JSON doesn't have, so you should make sure that your hash |
|
|
675 | keys are noticably shorter than the 1024 characters YAML allows. |
|
|
676 | |
|
|
677 | There might be other incompatibilities that I am not aware of. In general |
|
|
678 | you should not try to generate YAML with a JSON generator or vice versa, |
|
|
679 | or try to parse JSON with a YAML parser or vice versa: chances are high |
|
|
680 | that you will run into severe interoperability problems. |
|
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681 | |
|
|
682 | |
555 | =head2 SPEED |
683 | =head2 SPEED |
556 | |
684 | |
557 | It seems that JSON::XS is surprisingly fast, as shown in the following |
685 | It seems that JSON::XS is surprisingly fast, as shown in the following |
558 | tables. They have been generated with the help of the C<eg/bench> program |
686 | tables. They have been generated with the help of the C<eg/bench> program |
559 | in the JSON::XS distribution, to make it easy to compare on your own |
687 | in the JSON::XS distribution, to make it easy to compare on your own |
560 | system. |
688 | system. |
561 | |
689 | |
562 | First comes a comparison between various modules using a very short JSON |
690 | First comes a comparison between various modules using a very short |
563 | string: |
691 | single-line JSON string: |
564 | |
692 | |
565 | {"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null} |
693 | {"method": "handleMessage", "params": ["user1", "we were just talking"], \ |
|
|
694 | "id": null, "array":[1,11,234,-5,1e5,1e7, true, false]} |
566 | |
695 | |
567 | It shows the number of encodes/decodes per second (JSON::XS uses the |
696 | It shows the number of encodes/decodes per second (JSON::XS uses |
568 | functional interface, while JSON::XS/2 uses the OO interface with |
697 | the functional interface, while JSON::XS/2 uses the OO interface |
569 | pretty-printing and hashkey sorting enabled). Higher is better: |
698 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
|
|
699 | shrink). Higher is better: |
570 | |
700 | |
571 | module | encode | decode | |
701 | module | encode | decode | |
572 | -----------|------------|------------| |
702 | -----------|------------|------------| |
573 | JSON | 11488.516 | 7823.035 | |
703 | JSON | 7645.468 | 4208.613 | |
574 | JSON::DWIW | 94708.054 | 129094.260 | |
704 | JSON::DWIW | 40721.398 | 77101.176 | |
575 | JSON::PC | 63884.157 | 128528.212 | |
705 | JSON::PC | 65948.176 | 78251.940 | |
576 | JSON::Syck | 34898.677 | 42096.911 | |
706 | JSON::Syck | 22844.793 | 26479.192 | |
577 | JSON::XS | 654027.064 | 396423.669 | |
707 | JSON::XS | 388361.481 | 199728.762 | |
578 | JSON::XS/2 | 371564.190 | 371725.613 | |
708 | JSON::XS/2 | 218453.333 | 192399.266 | |
|
|
709 | JSON::XS/3 | 338250.323 | 192399.266 | |
|
|
710 | Storable | 15779.925 | 14169.946 | |
579 | -----------+------------+------------+ |
711 | -----------+------------+------------+ |
580 | |
712 | |
581 | That is, JSON::XS is more than six times faster than JSON::DWIW on |
713 | That is, JSON::XS is about five times faster than JSON::DWIW on encoding, |
582 | encoding, more than three times faster on decoding, and about thirty times |
714 | about three times faster on decoding, and over fourty times faster |
583 | faster than JSON, even with pretty-printing and key sorting. |
715 | than JSON, even with pretty-printing and key sorting. It also compares |
|
|
716 | favourably to Storable for small amounts of data. |
584 | |
717 | |
585 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
718 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
586 | search API (http://nanoref.com/yahooapis/mgPdGg): |
719 | search API (http://nanoref.com/yahooapis/mgPdGg): |
587 | |
720 | |
588 | module | encode | decode | |
721 | module | encode | decode | |
589 | -----------|------------|------------| |
722 | -----------|------------|------------| |
590 | JSON | 273.023 | 44.674 | |
723 | JSON | 254.685 | 37.665 | |
591 | JSON::DWIW | 1089.383 | 1145.704 | |
724 | JSON::DWIW | 843.343 | 1049.731 | |
592 | JSON::PC | 3097.419 | 2393.921 | |
725 | JSON::PC | 3602.116 | 2307.352 | |
593 | JSON::Syck | 514.060 | 843.053 | |
726 | JSON::Syck | 505.107 | 787.899 | |
594 | JSON::XS | 6479.668 | 3636.364 | |
727 | JSON::XS | 5747.196 | 3690.220 | |
595 | JSON::XS/2 | 3774.221 | 3599.124 | |
728 | JSON::XS/2 | 3968.121 | 3676.634 | |
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|
729 | JSON::XS/3 | 6105.246 | 3662.508 | |
|
|
730 | Storable | 4417.337 | 5285.161 | |
596 | -----------+------------+------------+ |
731 | -----------+------------+------------+ |
597 | |
732 | |
598 | Again, JSON::XS leads by far. |
733 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
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|
734 | decodes faster). |
599 | |
735 | |
600 | On large strings containing lots of high unicode characters, some modules |
736 | On large strings containing lots of high unicode characters, some modules |
601 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
737 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
602 | will be broken due to missing (or wrong) unicode handling. Others refuse |
738 | will be broken due to missing (or wrong) unicode handling. Others refuse |
603 | to decode or encode properly, so it was impossible to prepare a fair |
739 | to decode or encode properly, so it was impossible to prepare a fair |
… | |
… | |
620 | usually a good indication of the size of the resources required to decode |
756 | usually a good indication of the size of the resources required to decode |
621 | it into a Perl structure. |
757 | it into a Perl structure. |
622 | |
758 | |
623 | Third, JSON::XS recurses using the C stack when decoding objects and |
759 | Third, JSON::XS recurses using the C stack when decoding objects and |
624 | arrays. The C stack is a limited resource: for instance, on my amd64 |
760 | arrays. The C stack is a limited resource: for instance, on my amd64 |
625 | machine with 8MB of stack size I can decode around 180k nested arrays |
761 | machine with 8MB of stack size I can decode around 180k nested arrays but |
626 | but only 14k nested JSON objects. If that is exceeded, the program |
762 | only 14k nested JSON objects (due to perl itself recursing deeply on croak |
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|
763 | to free the temporary). If that is exceeded, the program crashes. to be |
627 | crashes. Thats why the default nesting limit is set to 8192. If your |
764 | conservative, the default nesting limit is set to 512. If your process |
628 | process has a smaller stack, you should adjust this setting accordingly |
765 | has a smaller stack, you should adjust this setting accordingly with the |
629 | with the C<max_depth> method. |
766 | C<max_depth> method. |
630 | |
767 | |
631 | And last but least, something else could bomb you that I forgot to think |
768 | And last but least, something else could bomb you that I forgot to think |
632 | of. In that case, you get to keep the pieces. I am alway sopen for hints, |
769 | of. In that case, you get to keep the pieces. I am always open for hints, |
633 | though... |
770 | though... |
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771 | |
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772 | If you are using JSON::XS to return packets to consumption |
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773 | by javascript scripts in a browser you should have a look at |
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|
774 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see wether |
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775 | you are vulnerable to some common attack vectors (which really are browser |
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776 | design bugs, but it is still you who will have to deal with it, as major |
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777 | browser developers care only for features, not about doing security |
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778 | right). |
634 | |
779 | |
635 | |
780 | |
636 | =head1 BUGS |
781 | =head1 BUGS |
637 | |
782 | |
638 | While the goal of this module is to be correct, that unfortunately does |
783 | While the goal of this module is to be correct, that unfortunately does |
… | |
… | |
640 | still relatively early in its development. If you keep reporting bugs they |
785 | still relatively early in its development. If you keep reporting bugs they |
641 | will be fixed swiftly, though. |
786 | will be fixed swiftly, though. |
642 | |
787 | |
643 | =cut |
788 | =cut |
644 | |
789 | |
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790 | our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; |
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791 | our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; |
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792 | |
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793 | sub true() { $true } |
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794 | sub false() { $false } |
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795 | |
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796 | sub is_bool($) { |
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797 | UNIVERSAL::isa $_[0], "JSON::XS::Boolean" |
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798 | # or UNIVERSAL::isa $_[0], "JSON::Literal" |
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|
799 | } |
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800 | |
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|
801 | XSLoader::load "JSON::XS", $VERSION; |
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802 | |
|
|
803 | package JSON::XS::Boolean; |
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804 | |
|
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805 | use overload |
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806 | "0+" => sub { ${$_[0]} }, |
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807 | "++" => sub { $_[0] = ${$_[0]} + 1 }, |
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|
808 | "--" => sub { $_[0] = ${$_[0]} - 1 }, |
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809 | fallback => 1; |
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810 | |
645 | 1; |
811 | 1; |
646 | |
812 | |
647 | =head1 AUTHOR |
813 | =head1 AUTHOR |
648 | |
814 | |
649 | Marc Lehmann <schmorp@schmorp.de> |
815 | Marc Lehmann <schmorp@schmorp.de> |