[ViewVC] Diff of: cvs/JSON-XS/XS.pm

Comparing JSON-XS/XS.pm (file contents):
Revision 1.13 by root, Fri Mar 23 18:37:30 2007 UTC vs.
Revision 1.29 by root, Mon Apr 9 05:09:57 2007 UTC

…		…
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use JSON::XS;	7	use JSON::XS;
8		8
9	# exported functions, croak on error	9	# exported functions, they croak on error
		10	# and expect/generate UTF-8
10		11
11	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;	12	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;
12	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;	13	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;
13		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	# oo-interface	19	# OO-interface
15		20
16	$coder = JSON::XS->new->ascii->pretty->allow_nonref;	21	$coder = JSON::XS->new->ascii->pretty->allow_nonref;
17	$pretty_printed_unencoded = $coder->encode ($perl_scalar);	22	$pretty_printed_unencoded = $coder->encode ($perl_scalar);
18	$perl_scalar = $coder->decode ($unicode_json_text);	23	$perl_scalar = $coder->decode ($unicode_json_text);
19		24
…		…
36		41
37	=head2 FEATURES	42	=head2 FEATURES
38		43
39	=over 4	44	=over 4
40		45
41	=item * correct handling of unicode issues	46	=item * correct unicode handling
42		47
43	This module knows how to handle Unicode, and even documents how and when	48	This module knows how to handle Unicode, and even documents how and when
44	it does so.	49	it does so.
45		50
46	=item * round-trip integrity	51	=item * round-trip integrity
47		52
48	When you serialise a perl data structure using only datatypes supported	53	When you serialise a perl data structure using only datatypes supported
49	by JSON, the deserialised data structure is identical on the Perl level.	54	by JSON, the deserialised data structure is identical on the Perl level.
50	(e.g. the string "2.0" doesn't suddenly become "2").	55	(e.g. the string "2.0" doesn't suddenly become "2" just because it looks
		56	like a number).
51		57
52	=item * strict checking of JSON correctness	58	=item * strict checking of JSON correctness
53		59
54	There is no guessing, no generating of illegal JSON strings by default,	60	There is no guessing, no generating of illegal JSON texts by default,
55	and only JSON is accepted as input by default (the latter is a security	61	and only JSON is accepted as input by default (the latter is a security
56	feature).	62	feature).
57		63
58	=item * fast	64	=item * fast
59		65
…		…
66	interface.	72	interface.
67		73
68	=item * reasonably versatile output formats	74	=item * reasonably versatile output formats
69		75
70	You can choose between the most compact guarenteed single-line format	76	You can choose between the most compact guarenteed single-line format
71	possible (nice for simple line-based protocols), a pure-ascii format (for	77	possible (nice for simple line-based protocols), a pure-ascii format
72	when your transport is not 8-bit clean), or a pretty-printed format (for	78	(for when your transport is not 8-bit clean, still supports the whole
73	when you want to read that stuff). Or you can combine those features in	79	unicode range), or a pretty-printed format (for when you want to read that
74	whatever way you like.	80	stuff). Or you can combine those features in whatever way you like.
75		81
76	=back	82	=back
77		83
78	=cut	84	=cut
79		85
80	package JSON::XS;	86	package JSON::XS;
81		87
		88	use strict;
		89
82	BEGIN {	90	BEGIN {
83	$VERSION = '0.3';	91	our $VERSION = '1.11';
84	@ISA = qw(Exporter);	92	our @ISA = qw(Exporter);
85		93
86	@EXPORT = qw(to_json from_json);	94	our @EXPORT = qw(to_json from_json objToJson jsonToObj);
87	require Exporter;	95	require Exporter;
88		96
89	require XSLoader;	97	require XSLoader;
90	XSLoader::load JSON::XS::, $VERSION;	98	XSLoader::load JSON::XS::, $VERSION;
91	}	99	}
…		…
95	The following convinience methods are provided by this module. They are	103	The following convinience methods are provided by this module. They are
96	exported by default:	104	exported by default:
97		105
98	=over 4	106	=over 4
99		107
100	=item $json_string = to_json $perl_scalar	108	=item $json_text = to_json $perl_scalar
101		109
102	Converts the given Perl data structure (a simple scalar or a reference to	110	Converts the given Perl data structure (a simple scalar or a reference to
103	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains	111	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains
104	octets only). Croaks on error.	112	octets only). Croaks on error.
105		113
106	This function call is functionally identical to C<< JSON::XS->new->utf8->encode ($perl_scalar) >>.	114	This function call is functionally identical to:
107		115
		116	$json_text = JSON::XS->new->utf8->encode ($perl_scalar)
		117
		118	except being faster.
		119
108	=item $perl_scalar = from_json $json_string	120	=item $perl_scalar = from_json $json_text
109		121
110	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to	122	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to
111	parse that as an UTF-8 encoded JSON string, returning the resulting simple	123	parse that as an UTF-8 encoded JSON text, returning the resulting simple
112	scalar or reference. Croaks on error.	124	scalar or reference. Croaks on error.
113		125
114	This function call is functionally identical to C<< JSON::XS->new->utf8->decode ($json_string) >>.	126	This function call is functionally identical to:
		127
		128	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)
		129
		130	except being faster.
115		131
116	=back	132	=back
		133
117		134
118	=head1 OBJECT-ORIENTED INTERFACE	135	=head1 OBJECT-ORIENTED INTERFACE
119		136
120	The object oriented interface lets you configure your own encoding or	137	The object oriented interface lets you configure your own encoding or
121	decoding style, within the limits of supported formats.	138	decoding style, within the limits of supported formats.
…		…
128	strings. All boolean flags described below are by default I<disabled>.	145	strings. All boolean flags described below are by default I<disabled>.
129		146
130	The mutators for flags all return the JSON object again and thus calls can	147	The mutators for flags all return the JSON object again and thus calls can
131	be chained:	148	be chained:
132		149
133	my $json = JSON::XS->new->utf8(1)->space_after(1)->encode ({a => [1,2]})	150	my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]})
134	=> {"a": [1, 2]}	151	=> {"a": [1, 2]}
135		152
136	=item $json = $json->ascii ([$enable])	153	=item $json = $json->ascii ([$enable])
137		154
138	If C<$enable> is true (or missing), then the C<encode> method will	155	If C<$enable> is true (or missing), then the C<encode> method will not
139	not generate characters outside the code range C<0..127>. Any unicode	156	generate characters outside the code range C<0..127> (which is ASCII). Any
140	characters outside that range will be escaped using either a single	157	unicode characters outside that range will be escaped using either a
141	\uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, as per	158	single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence,
142	RFC4627.	159	as per RFC4627.
143		160
144	If C<$enable> is false, then the C<encode> method will not escape Unicode	161	If C<$enable> is false, then the C<encode> method will not escape Unicode
145	characters unless necessary.	162	characters unless required by the JSON syntax. This results in a faster
		163	and more compact format.
146		164
147	JSON::XS->new->ascii (1)->encode (chr 0x10401)	165	JSON::XS->new->ascii (1)->encode ([chr 0x10401])
148	=> \ud801\udc01	166	=> ["\ud801\udc01"]
149		167
150	=item $json = $json->utf8 ([$enable])	168	=item $json = $json->utf8 ([$enable])
151		169
152	If C<$enable> is true (or missing), then the C<encode> method will encode	170	If C<$enable> is true (or missing), then the C<encode> method will encode
153	the JSON string into UTF-8, as required by many protocols, while the	171	the JSON result into UTF-8, as required by many protocols, while the
154	C<decode> method expects to be handled an UTF-8-encoded string. Please	172	C<decode> method expects to be handled an UTF-8-encoded string. Please
155	note that UTF-8-encoded strings do not contain any characters outside the	173	note that UTF-8-encoded strings do not contain any characters outside the
156	range C<0..255>, they are thus useful for bytewise/binary I/O.	174	range C<0..255>, they are thus useful for bytewise/binary I/O. In future
		175	versions, enabling this option might enable autodetection of the UTF-16
		176	and UTF-32 encoding families, as described in RFC4627.
157		177
158	If C<$enable> is false, then the C<encode> method will return the JSON	178	If C<$enable> is false, then the C<encode> method will return the JSON
159	string as a (non-encoded) unicode string, while C<decode> expects thus a	179	string as a (non-encoded) unicode string, while C<decode> expects thus a
160	unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs	180	unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs
161	to be done yourself, e.g. using the Encode module.	181	to be done yourself, e.g. using the Encode module.
162		182
163	Example, output UTF-16-encoded JSON:	183	Example, output UTF-16BE-encoded JSON:
		184
		185	use Encode;
		186	$jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object);
		187
		188	Example, decode UTF-32LE-encoded JSON:
		189
		190	use Encode;
		191	$object = JSON::XS->new->decode (decode "UTF-32LE", $jsontext);
164		192
165	=item $json = $json->pretty ([$enable])	193	=item $json = $json->pretty ([$enable])
166		194
167	This enables (or disables) all of the C<indent>, C<space_before> and	195	This enables (or disables) all of the C<indent>, C<space_before> and
168	C<space_after> (and in the future possibly more) flags in one call to	196	C<space_after> (and in the future possibly more) flags in one call to
…		…
184	If C<$enable> is true (or missing), then the C<encode> method will use a multiline	212	If C<$enable> is true (or missing), then the C<encode> method will use a multiline
185	format as output, putting every array member or object/hash key-value pair	213	format as output, putting every array member or object/hash key-value pair
186	into its own line, identing them properly.	214	into its own line, identing them properly.
187		215
188	If C<$enable> is false, no newlines or indenting will be produced, and the	216	If C<$enable> is false, no newlines or indenting will be produced, and the
189	resulting JSON strings is guarenteed not to contain any C<newlines>.	217	resulting JSON text is guarenteed not to contain any C<newlines>.
190		218
191	This setting has no effect when decoding JSON strings.	219	This setting has no effect when decoding JSON texts.
192		220
193	=item $json = $json->space_before ([$enable])	221	=item $json = $json->space_before ([$enable])
194		222
195	If C<$enable> is true (or missing), then the C<encode> method will add an extra	223	If C<$enable> is true (or missing), then the C<encode> method will add an extra
196	optional space before the C<:> separating keys from values in JSON objects.	224	optional space before the C<:> separating keys from values in JSON objects.
197		225
198	If C<$enable> is false, then the C<encode> method will not add any extra	226	If C<$enable> is false, then the C<encode> method will not add any extra
199	space at those places.	227	space at those places.
200		228
201	This setting has no effect when decoding JSON strings. You will also most	229	This setting has no effect when decoding JSON texts. You will also
202	likely combine this setting with C<space_after>.	230	most likely combine this setting with C<space_after>.
203		231
204	Example, space_before enabled, space_after and indent disabled:	232	Example, space_before enabled, space_after and indent disabled:
205		233
206	{"key" :"value"}	234	{"key" :"value"}
207		235
…		…
213	members.	241	members.
214		242
215	If C<$enable> is false, then the C<encode> method will not add any extra	243	If C<$enable> is false, then the C<encode> method will not add any extra
216	space at those places.	244	space at those places.
217		245
218	This setting has no effect when decoding JSON strings.	246	This setting has no effect when decoding JSON texts.
219		247
220	Example, space_before and indent disabled, space_after enabled:	248	Example, space_before and indent disabled, space_after enabled:
221		249
222	{"key": "value"}	250	{"key": "value"}
223		251
…		…
229	If C<$enable> is false, then the C<encode> method will output key-value	257	If C<$enable> is false, then the C<encode> method will output key-value
230	pairs in the order Perl stores them (which will likely change between runs	258	pairs in the order Perl stores them (which will likely change between runs
231	of the same script).	259	of the same script).
232		260
233	This option is useful if you want the same data structure to be encoded as	261	This option is useful if you want the same data structure to be encoded as
234	the same JSON string (given the same overall settings). If it is disabled,	262	the same JSON text (given the same overall settings). If it is disabled,
235	the same hash migh be encoded differently even if contains the same data,	263	the same hash migh be encoded differently even if contains the same data,
236	as key-value pairs have no inherent ordering in Perl.	264	as key-value pairs have no inherent ordering in Perl.
237		265
238	This setting has no effect when decoding JSON strings.	266	This setting has no effect when decoding JSON texts.
239		267
240	=item $json = $json->allow_nonref ([$enable])	268	=item $json = $json->allow_nonref ([$enable])
241		269
242	If C<$enable> is true (or missing), then the C<encode> method can convert a	270	If C<$enable> is true (or missing), then the C<encode> method can convert a
243	non-reference into its corresponding string, number or null JSON value,	271	non-reference into its corresponding string, number or null JSON value,
244	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON	272	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON
245	values instead of croaking.	273	values instead of croaking.
246		274
247	If C<$enable> is false, then the C<encode> method will croak if it isn't	275	If C<$enable> is false, then the C<encode> method will croak if it isn't
248	passed an arrayref or hashref, as JSON strings must either be an object	276	passed an arrayref or hashref, as JSON texts must either be an object
249	or array. Likewise, C<decode> will croak if given something that is not a	277	or array. Likewise, C<decode> will croak if given something that is not a
250	JSON object or array.	278	JSON object or array.
251		279
252	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,	280	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,
253	resulting in an invalid JSON text:	281	resulting in an invalid JSON text:
…		…
256	=> "Hello, World!"	284	=> "Hello, World!"
257		285
258	=item $json = $json->shrink ([$enable])	286	=item $json = $json->shrink ([$enable])
259		287
260	Perl usually over-allocates memory a bit when allocating space for	288	Perl usually over-allocates memory a bit when allocating space for
261	strings. This flag optionally resizes strings generated by either	289	strings. This flag optionally resizes strings generated by either
262	C<encode> or C<decode> to their minimum size possible. This can save	290	C<encode> or C<decode> to their minimum size possible. This can save
263	memory when your JSON strings are either very very long or you have many	291	memory when your JSON texts are either very very long or you have many
264	short strings. It will also try to downgrade any strings to octet-form	292	short strings. It will also try to downgrade any strings to octet-form
265	if possible: perl stores strings internally either in an encoding called	293	if possible: perl stores strings internally either in an encoding called
266	UTF-X or in octet-form. The latter cannot store everything but uses less	294	UTF-X or in octet-form. The latter cannot store everything but uses less
267	space in general.	295	space in general (and some buggy Perl or C code might even rely on that
		296	internal representation being used).
268		297
		298	The actual definition of what shrink does might change in future versions,
		299	but it will always try to save space at the expense of time.
		300
269	If C<$enable> is true (or missing), the string returned by C<encode> will be shrunk-to-fit,	301	If C<$enable> is true (or missing), the string returned by C<encode> will
270	while all strings generated by C<decode> will also be shrunk-to-fit.	302	be shrunk-to-fit, while all strings generated by C<decode> will also be
		303	shrunk-to-fit.
271		304
272	If C<$enable> is false, then the normal perl allocation algorithms are used.	305	If C<$enable> is false, then the normal perl allocation algorithms are used.
273	If you work with your data, then this is likely to be faster.	306	If you work with your data, then this is likely to be faster.
274		307
275	In the future, this setting might control other things, such as converting	308	In the future, this setting might control other things, such as converting
276	strings that look like integers or floats into integers or floats	309	strings that look like integers or floats into integers or floats
277	internally (there is no difference on the Perl level), saving space.	310	internally (there is no difference on the Perl level), saving space.
278		311
		312	=item $json = $json->max_depth ([$maximum_nesting_depth])
		313
		314	Sets the maximum nesting level (default C<512>) accepted while encoding
		315	or decoding. If the JSON text or Perl data structure has an equal or
		316	higher nesting level then this limit, then the encoder and decoder will
		317	stop and croak at that point.
		318
		319	Nesting level is defined by number of hash- or arrayrefs that the encoder
		320	needs to traverse to reach a given point or the number of C<{> or C<[>
		321	characters without their matching closing parenthesis crossed to reach a
		322	given character in a string.
		323
		324	Setting the maximum depth to one disallows any nesting, so that ensures
		325	that the object is only a single hash/object or array.
		326
		327	The argument to C<max_depth> will be rounded up to the next nearest power
		328	of two.
		329
		330	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
		331
279	=item $json_string = $json->encode ($perl_scalar)	332	=item $json_text = $json->encode ($perl_scalar)
280		333
281	Converts the given Perl data structure (a simple scalar or a reference	334	Converts the given Perl data structure (a simple scalar or a reference
282	to a hash or array) to its JSON representation. Simple scalars will be	335	to a hash or array) to its JSON representation. Simple scalars will be
283	converted into JSON string or number sequences, while references to arrays	336	converted into JSON string or number sequences, while references to arrays
284	become JSON arrays and references to hashes become JSON objects. Undefined	337	become JSON arrays and references to hashes become JSON objects. Undefined
285	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>	338	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>
286	nor C<false> values will be generated.	339	nor C<false> values will be generated.
287		340
288	=item $perl_scalar = $json->decode ($json_string)	341	=item $perl_scalar = $json->decode ($json_text)
289		342
290	The opposite of C<encode>: expects a JSON string and tries to parse it,	343	The opposite of C<encode>: expects a JSON text and tries to parse it,
291	returning the resulting simple scalar or reference. Croaks on error.	344	returning the resulting simple scalar or reference. Croaks on error.
292		345
293	JSON numbers and strings become simple Perl scalars. JSON arrays become	346	JSON numbers and strings become simple Perl scalars. JSON arrays become
294	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes	347	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes
295	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.	348	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.
296		349
297	=back	350	=back
		351
298		352
299	=head1 MAPPING	353	=head1 MAPPING
300		354
301	This section describes how JSON::XS maps Perl values to JSON values and	355	This section describes how JSON::XS maps Perl values to JSON values and
302	vice versa. These mappings are designed to "do the right thing" in most	356	vice versa. These mappings are designed to "do the right thing" in most
…		…
312	=over 4	366	=over 4
313		367
314	=item object	368	=item object
315		369
316	A JSON object becomes a reference to a hash in Perl. No ordering of object	370	A JSON object becomes a reference to a hash in Perl. No ordering of object
317	keys is preserved.	371	keys is preserved (JSON does not preserver object key ordering itself).
318		372
319	=item array	373	=item array
320		374
321	A JSON array becomes a reference to an array in Perl.	375	A JSON array becomes a reference to an array in Perl.
322		376
…		…
356	=over 4	410	=over 4
357		411
358	=item hash references	412	=item hash references
359		413
360	Perl hash references become JSON objects. As there is no inherent ordering	414	Perl hash references become JSON objects. As there is no inherent ordering
361	in hash keys, they will usually be encoded in a pseudo-random order that	415	in hash keys (or JSON objects), they will usually be encoded in a
362	can change between runs of the same program but stays generally the same	416	pseudo-random order that can change between runs of the same program but
363	within the single run of a program. JSON::XS can optionally sort the hash	417	stays generally the same within a single run of a program. JSON::XS can
364	keys (determined by the I<canonical> flag), so the same datastructure	418	optionally sort the hash keys (determined by the I<canonical> flag), so
365	will serialise to the same JSON text (given same settings and version of	419	the same datastructure will serialise to the same JSON text (given same
366	JSON::XS), but this incurs a runtime overhead.	420	settings and version of JSON::XS), but this incurs a runtime overhead
		421	and is only rarely useful, e.g. when you want to compare some JSON text
		422	against another for equality.
367		423
368	=item array references	424	=item array references
369		425
370	Perl array references become JSON arrays.	426	Perl array references become JSON arrays.
		427
		428	=item other references
		429
		430	Other unblessed references are generally not allowed and will cause an
		431	exception to be thrown, except for references to the integers C<0> and
		432	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.
		434
		435	to_json [\0,JSON::XS::true] # yields [false,true]
371		436
372	=item blessed objects	437	=item blessed objects
373		438
374	Blessed objects are not allowed. JSON::XS currently tries to encode their	439	Blessed objects are not allowed. JSON::XS currently tries to encode their
375	underlying representation (hash- or arrayref), but this behaviour might	440	underlying representation (hash- or arrayref), but this behaviour might
…		…
408	$x *= 1; # same thing, the choise is yours.	473	$x *= 1; # same thing, the choise is yours.
409		474
410	You can not currently output JSON booleans or force the type in other,	475	You can not currently output JSON booleans or force the type in other,
411	less obscure, ways. Tell me if you need this capability.	476	less obscure, ways. Tell me if you need this capability.
412		477
413	=item circular data structures
414
415	Those will be encoded until memory or stackspace runs out.
416
417	=back	478	=back
		479
418		480
419	=head1 COMPARISON	481	=head1 COMPARISON
420		482
421	As already mentioned, this module was created because none of the existing	483	As already mentioned, this module was created because none of the existing
422	JSON modules could be made to work correctly. First I will describe the	484	JSON modules could be made to work correctly. First I will describe the
…		…
448		510
449	Has problems handling many Perl values (e.g. regex results and other magic	511	Has problems handling many Perl values (e.g. regex results and other magic
450	values will make it croak).	512	values will make it croak).
451		513
452	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>	514	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>
453	which is not a valid JSON string.	515	which is not a valid JSON text.
454		516
455	Unmaintained (maintainer unresponsive for many months, bugs are not	517	Unmaintained (maintainer unresponsive for many months, bugs are not
456	getting fixed).	518	getting fixed).
457		519
458	=item JSON::Syck 0.21	520	=item JSON::Syck 0.21
…		…
460	Very buggy (often crashes).	522	Very buggy (often crashes).
461		523
462	Very inflexible (no human-readable format supported, format pretty much	524	Very inflexible (no human-readable format supported, format pretty much
463	undocumented. I need at least a format for easy reading by humans and a	525	undocumented. I need at least a format for easy reading by humans and a
464	single-line compact format for use in a protocol, and preferably a way to	526	single-line compact format for use in a protocol, and preferably a way to
465	generate ASCII-only JSON strings).	527	generate ASCII-only JSON texts).
466		528
467	Completely broken (and confusingly documented) Unicode handling (unicode	529	Completely broken (and confusingly documented) Unicode handling (unicode
468	escapes are not working properly, you need to set ImplicitUnicode to	530	escapes are not working properly, you need to set ImplicitUnicode to
469	I<different> values on en- and decoding to get symmetric behaviour).	531	I<different> values on en- and decoding to get symmetric behaviour).
470		532
…		…
493		555
494	Very inflexible.	556	Very inflexible.
495		557
496	No roundtripping.	558	No roundtripping.
497		559
498	Does not generate valid JSON (key strings are often unquoted, empty keys	560	Does not generate valid JSON texts (key strings are often unquoted, empty keys
499	result in nothing being output)	561	result in nothing being output)
500		562
501	Does not check input for validity.	563	Does not check input for validity.
502		564
503	=back	565	=back
…		…
508	tables. They have been generated with the help of the C<eg/bench> program	570	tables. They have been generated with the help of the C<eg/bench> program
509	in the JSON::XS distribution, to make it easy to compare on your own	571	in the JSON::XS distribution, to make it easy to compare on your own
510	system.	572	system.
511		573
512	First comes a comparison between various modules using a very short JSON	574	First comes a comparison between various modules using a very short JSON
513	string (83 bytes), showing the number of encodes/decodes per second	575	string:
514	(JSON::XS is the functional interface, while JSON::XS/2 is the OO	576
		577	{"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null}
		578
		579	It shows the number of encodes/decodes per second (JSON::XS uses the
		580	functional interface, while JSON::XS/2 uses the OO interface with
515	interface with pretty-printing and hashkey sorting enabled). Higher is	581	pretty-printing and hashkey sorting enabled). Higher is better:
516	better:
517		582
518	module \| encode \| decode \|	583	module \| encode \| decode \|
519	-----------\|------------\|------------\|	584	-----------\|------------\|------------\|
520	JSON \| 14006 \| 6820 \|	585	JSON \| 11488.516 \| 7823.035 \|
521	JSON::DWIW \| 200937 \| 120386 \|	586	JSON::DWIW \| 94708.054 \| 129094.260 \|
522	JSON::PC \| 85065 \| 129366 \|	587	JSON::PC \| 63884.157 \| 128528.212 \|
523	JSON::Syck \| 59898 \| 44232 \|	588	JSON::Syck \| 34898.677 \| 42096.911 \|
524	JSON::XS \| 1171478 \| 342435 \|	589	JSON::XS \| 654027.064 \| 396423.669 \|
525	JSON::XS/2 \| 730760 \| 328714 \|	590	JSON::XS/2 \| 371564.190 \| 371725.613 \|
526	-----------+------------+------------+	591	-----------+------------+------------+
527		592
528	That is, JSON::XS is 6 times faster than than JSON::DWIW and about 80	593	That is, JSON::XS is more than six times faster than JSON::DWIW on
		594	encoding, more than three times faster on decoding, and about thirty times
529	times faster than JSON, even with pretty-printing and key sorting.	595	faster than JSON, even with pretty-printing and key sorting.
530		596
531	Using a longer test string (roughly 18KB, generated from Yahoo! Locals	597	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
532	search API (http://nanoref.com/yahooapis/mgPdGg):	598	search API (http://nanoref.com/yahooapis/mgPdGg):
533		599
534	module \| encode \| decode \|	600	module \| encode \| decode \|
535	-----------\|------------\|------------\|	601	-----------\|------------\|------------\|
536	JSON \| 673 \| 38 \|	602	JSON \| 273.023 \| 44.674 \|
537	JSON::DWIW \| 5271 \| 770 \|	603	JSON::DWIW \| 1089.383 \| 1145.704 \|
538	JSON::PC \| 9901 \| 2491 \|	604	JSON::PC \| 3097.419 \| 2393.921 \|
539	JSON::Syck \| 2360 \| 786 \|	605	JSON::Syck \| 514.060 \| 843.053 \|
540	JSON::XS \| 37398 \| 3202 \|	606	JSON::XS \| 6479.668 \| 3636.364 \|
541	JSON::XS/2 \| 13765 \| 3153 \|	607	JSON::XS/2 \| 3774.221 \| 3599.124 \|
542	-----------+------------+------------+	608	-----------+------------+------------+
543		609
544	Again, JSON::XS leads by far in the encoding case, while still beating	610	Again, JSON::XS leads by far.
545	every other module in the decoding case.
546		611
547	On large strings containing lots of unicode characters, some modules	612	On large strings containing lots of high unicode characters, some modules
548	(such as JSON::PC) decode faster than JSON::XS, but the result will be	613	(such as JSON::PC) seem to decode faster than JSON::XS, but the result
549	broken due to missing unicode handling. Others refuse to decode or encode	614	will be broken due to missing (or wrong) unicode handling. Others refuse
550	properly, so it was impossible to prepare a fair comparison table for that	615	to decode or encode properly, so it was impossible to prepare a fair
551	case.	616	comparison table for that case.
552		617
553	=head1 RESOURCE LIMITS
554		618
555	JSON::XS does not impose any limits on the size of JSON texts or Perl	619	=head1 SECURITY CONSIDERATIONS
556	values they represent - if your machine can handle it, JSON::XS will	620
557	encode or decode it. Future versions might optionally impose structure	621	When you are using JSON in a protocol, talking to untrusted potentially
558	depth and memory use resource limits.	622	hostile creatures requires relatively few measures.
		623
		624	First of all, your JSON decoder should be secure, that is, should not have
		625	any buffer overflows. Obviously, this module should ensure that and I am
		626	trying hard on making that true, but you never know.
		627
		628	Second, you need to avoid resource-starving attacks. That means you should
		629	limit the size of JSON texts you accept, or make sure then when your
		630	resources run out, thats just fine (e.g. by using a separate process that
		631	can crash safely). The size of a JSON text in octets or characters is
		632	usually a good indication of the size of the resources required to decode
		633	it into a Perl structure.
		634
		635	Third, JSON::XS recurses using the C stack when decoding objects and
		636	arrays. The C stack is a limited resource: for instance, on my amd64
		637	machine with 8MB of stack size I can decode around 180k nested arrays but
		638	only 14k nested JSON objects (due to perl itself recursing deeply on croak
		639	to free the temporary). If that is exceeded, the program crashes. to be
		640	conservative, the default nesting limit is set to 512. If your process
		641	has a smaller stack, you should adjust this setting accordingly with the
		642	C<max_depth> method.
		643
		644	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 alway sopen for hints,
		646	though...
		647
559		648
560	=head1 BUGS	649	=head1 BUGS
561		650
562	While the goal of this module is to be correct, that unfortunately does	651	While the goal of this module is to be correct, that unfortunately does
563	not mean its bug-free, only that I think its design is bug-free. It is	652	not mean its bug-free, only that I think its design is bug-free. It is
564	still very young and not well-tested. If you keep reporting bugs they will	653	still relatively early in its development. If you keep reporting bugs they
565	be fixed swiftly, though.	654	will be fixed swiftly, though.
566		655
567	=cut	656	=cut
		657
		658	sub true() { \1 }
		659	sub false() { \0 }
568		660
569	1;	661	1;
570		662
571	=head1 AUTHOR	663	=head1 AUTHOR
572		664

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Comparing JSON-XS/XS.pm (file contents): Revision 1.13 by root, Fri Mar 23 18:37:30 2007 UTC vs. Revision 1.29 by root, Mon Apr 9 05:09:57 2007 UTC

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Comparing JSON-XS/XS.pm (file contents):
Revision 1.13 by root, Fri Mar 23 18:37:30 2007 UTC vs.
Revision 1.29 by root, Mon Apr 9 05:09:57 2007 UTC