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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.11 by root, Fri Mar 23 17:48:59 2007 UTC vs.
Revision 1.32 by root, Thu Apr 12 07:25:29 2007 UTC

…		…
3	JSON::XS - JSON serialising/deserialising, done correctly and fast	3	JSON::XS - JSON serialising/deserialising, done correctly and fast
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use JSON::XS;	7	use JSON::XS;
		8
		9	# exported functions, they croak on error
		10	# and expect/generate UTF-8
		11
		12	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;
		13	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;
		14
		15	# objToJson and jsonToObj aliases to to_json and from_json
		16	# are exported for compatibility to the JSON module,
		17	# but should not be used in new code.
		18
		19	# OO-interface
		20
		21	$coder = JSON::XS->new->ascii->pretty->allow_nonref;
		22	$pretty_printed_unencoded = $coder->encode ($perl_scalar);
		23	$perl_scalar = $coder->decode ($unicode_json_text);
8		24
9	=head1 DESCRIPTION	25	=head1 DESCRIPTION
10		26
11	This module converts Perl data structures to JSON and vice versa. Its	27	This module converts Perl data structures to JSON and vice versa. Its
12	primary goal is to be I<correct> and its secondary goal is to be	28	primary goal is to be I<correct> and its secondary goal is to be
…		…
25		41
26	=head2 FEATURES	42	=head2 FEATURES
27		43
28	=over 4	44	=over 4
29		45
30	=item * correct handling of unicode issues	46	=item * correct unicode handling
31		47
32	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
33	it does so.	49	it does so.
34		50
35	=item * round-trip integrity	51	=item * round-trip integrity
36		52
37	When you serialise a perl data structure using only datatypes supported	53	When you serialise a perl data structure using only datatypes supported
38	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.
39	(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).
40		57
41	=item * strict checking of JSON correctness	58	=item * strict checking of JSON correctness
42		59
43	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,
44	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
45	feature).	62	feature).
46		63
47	=item * fast	64	=item * fast
48		65
…		…
55	interface.	72	interface.
56		73
57	=item * reasonably versatile output formats	74	=item * reasonably versatile output formats
58		75
59	You can choose between the most compact guarenteed single-line format	76	You can choose between the most compact guarenteed single-line format
60	possible (nice for simple line-based protocols), a pure-ascii format (for	77	possible (nice for simple line-based protocols), a pure-ascii format
61	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
62	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
63	whatever way you like.	80	stuff). Or you can combine those features in whatever way you like.
64		81
65	=back	82	=back
66		83
67	=cut	84	=cut
68		85
69	package JSON::XS;	86	package JSON::XS;
70		87
		88	use strict;
		89
71	BEGIN {	90	BEGIN {
72	$VERSION = '0.3';	91	our $VERSION = '1.12';
73	@ISA = qw(Exporter);	92	our @ISA = qw(Exporter);
74		93
75	@EXPORT = qw(to_json from_json);	94	our @EXPORT = qw(to_json from_json objToJson jsonToObj);
76	require Exporter;	95	require Exporter;
77		96
78	require XSLoader;	97	require XSLoader;
79	XSLoader::load JSON::XS::, $VERSION;	98	XSLoader::load JSON::XS::, $VERSION;
80	}	99	}
…		…
84	The following convinience methods are provided by this module. They are	103	The following convinience methods are provided by this module. They are
85	exported by default:	104	exported by default:
86		105
87	=over 4	106	=over 4
88		107
89	=item $json_string = to_json $perl_scalar	108	=item $json_text = to_json $perl_scalar
90		109
91	Converts the given Perl data structure (a simple scalar or a reference to	110	Converts the given Perl data structure (a simple scalar or a reference to
92	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains	111	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains
93	octets only). Croaks on error.	112	octets only). Croaks on error.
94		113
95	This function call is functionally identical to C<< JSON::XS->new->utf8->encode ($perl_scalar) >>.	114	This function call is functionally identical to:
96		115
		116	$json_text = JSON::XS->new->utf8->encode ($perl_scalar)
		117
		118	except being faster.
		119
97	=item $perl_scalar = from_json $json_string	120	=item $perl_scalar = from_json $json_text
98		121
99	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to	122	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to
100	parse that as an UTF-8 encoded JSON string, returning the resulting simple	123	parse that as an UTF-8 encoded JSON text, returning the resulting simple
101	scalar or reference. Croaks on error.	124	scalar or reference. Croaks on error.
102		125
103	This function call is functionally identical to C<< JSON::XS->new->utf8->decode ($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.
104		131
105	=back	132	=back
		133
106		134
107	=head1 OBJECT-ORIENTED INTERFACE	135	=head1 OBJECT-ORIENTED INTERFACE
108		136
109	The object oriented interface lets you configure your own encoding or	137	The object oriented interface lets you configure your own encoding or
110	decoding style, within the limits of supported formats.	138	decoding style, within the limits of supported formats.
…		…
117	strings. All boolean flags described below are by default I<disabled>.	145	strings. All boolean flags described below are by default I<disabled>.
118		146
119	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
120	be chained:	148	be chained:
121		149
122	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]})
123	=> {"a": [1, 2]}	151	=> {"a": [1, 2]}
124		152
125	=item $json = $json->ascii ([$enable])	153	=item $json = $json->ascii ([$enable])
126		154
127	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
128	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
129	characters outside that range will be escaped using either a single	157	unicode characters outside that range will be escaped using either a
130	\uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, as per	158	single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence,
131	RFC4627.	159	as per RFC4627. The resulting encoded JSON text can be treated as a native
		160	unicode string, an ascii-encoded, latin1-encoded or UTF-8 encoded string,
		161	or any other superset of ASCII.
132		162
133	If C<$enable> is false, then the C<encode> method will not escape Unicode	163	If C<$enable> is false, then the C<encode> method will not escape Unicode
134	characters unless necessary.	164	characters unless required by the JSON syntax. This results in a faster
		165	and more compact format.
135		166
136	JSON::XS->new->ascii (1)->encode (chr 0x10401)	167	JSON::XS->new->ascii (1)->encode ([chr 0x10401])
137	=> \ud801\udc01	168	=> ["\ud801\udc01"]
138		169
139	=item $json = $json->utf8 ([$enable])	170	=item $json = $json->utf8 ([$enable])
140		171
141	If C<$enable> is true (or missing), then the C<encode> method will encode	172	If C<$enable> is true (or missing), then the C<encode> method will encode
142	the JSON string into UTF-8, as required by many protocols, while the	173	the JSON result into UTF-8, as required by many protocols, while the
143	C<decode> method expects to be handled an UTF-8-encoded string. Please	174	C<decode> method expects to be handled an UTF-8-encoded string. Please
144	note that UTF-8-encoded strings do not contain any characters outside the	175	note that UTF-8-encoded strings do not contain any characters outside the
145	range C<0..255>, they are thus useful for bytewise/binary I/O.	176	range C<0..255>, they are thus useful for bytewise/binary I/O. In future
		177	versions, enabling this option might enable autodetection of the UTF-16
		178	and UTF-32 encoding families, as described in RFC4627.
146		179
147	If C<$enable> is false, then the C<encode> method will return the JSON	180	If C<$enable> is false, then the C<encode> method will return the JSON
148	string as a (non-encoded) unicode string, while C<decode> expects thus a	181	string as a (non-encoded) unicode string, while C<decode> expects thus a
149	unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs	182	unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs
150	to be done yourself, e.g. using the Encode module.	183	to be done yourself, e.g. using the Encode module.
151		184
		185	Example, output UTF-16BE-encoded JSON:
		186
		187	use Encode;
		188	$jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object);
		189
		190	Example, decode UTF-32LE-encoded JSON:
		191
		192	use Encode;
		193	$object = JSON::XS->new->decode (decode "UTF-32LE", $jsontext);
		194
152	=item $json = $json->pretty ([$enable])	195	=item $json = $json->pretty ([$enable])
153		196
154	This enables (or disables) all of the C<indent>, C<space_before> and	197	This enables (or disables) all of the C<indent>, C<space_before> and
155	C<space_after> (and in the future possibly more) flags in one call to	198	C<space_after> (and in the future possibly more) flags in one call to
156	generate the most readable (or most compact) form possible.	199	generate the most readable (or most compact) form possible.
		200
		201	Example, pretty-print some simple structure:
157		202
158	my $json = JSON::XS->new->pretty(1)->encode ({a => [1,2]})	203	my $json = JSON::XS->new->pretty(1)->encode ({a => [1,2]})
159	=>	204	=>
160	{	205	{
161	"a" : [	206	"a" : [
…		…
169	If C<$enable> is true (or missing), then the C<encode> method will use a multiline	214	If C<$enable> is true (or missing), then the C<encode> method will use a multiline
170	format as output, putting every array member or object/hash key-value pair	215	format as output, putting every array member or object/hash key-value pair
171	into its own line, identing them properly.	216	into its own line, identing them properly.
172		217
173	If C<$enable> is false, no newlines or indenting will be produced, and the	218	If C<$enable> is false, no newlines or indenting will be produced, and the
174	resulting JSON strings is guarenteed not to contain any C<newlines>.	219	resulting JSON text is guarenteed not to contain any C<newlines>.
175		220
176	This setting has no effect when decoding JSON strings.	221	This setting has no effect when decoding JSON texts.
177		222
178	=item $json = $json->space_before ([$enable])	223	=item $json = $json->space_before ([$enable])
179		224
180	If C<$enable> is true (or missing), then the C<encode> method will add an extra	225	If C<$enable> is true (or missing), then the C<encode> method will add an extra
181	optional space before the C<:> separating keys from values in JSON objects.	226	optional space before the C<:> separating keys from values in JSON objects.
182		227
183	If C<$enable> is false, then the C<encode> method will not add any extra	228	If C<$enable> is false, then the C<encode> method will not add any extra
184	space at those places.	229	space at those places.
185		230
186	This setting has no effect when decoding JSON strings. You will also most	231	This setting has no effect when decoding JSON texts. You will also
187	likely combine this setting with C<space_after>.	232	most likely combine this setting with C<space_after>.
		233
		234	Example, space_before enabled, space_after and indent disabled:
		235
		236	{"key" :"value"}
188		237
189	=item $json = $json->space_after ([$enable])	238	=item $json = $json->space_after ([$enable])
190		239
191	If C<$enable> is true (or missing), then the C<encode> method will add an extra	240	If C<$enable> is true (or missing), then the C<encode> method will add an extra
192	optional space after the C<:> separating keys from values in JSON objects	241	optional space after the C<:> separating keys from values in JSON objects
…		…
194	members.	243	members.
195		244
196	If C<$enable> is false, then the C<encode> method will not add any extra	245	If C<$enable> is false, then the C<encode> method will not add any extra
197	space at those places.	246	space at those places.
198		247
199	This setting has no effect when decoding JSON strings.	248	This setting has no effect when decoding JSON texts.
		249
		250	Example, space_before and indent disabled, space_after enabled:
		251
		252	{"key": "value"}
200		253
201	=item $json = $json->canonical ([$enable])	254	=item $json = $json->canonical ([$enable])
202		255
203	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects	256	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
204	by sorting their keys. This is adding a comparatively high overhead.	257	by sorting their keys. This is adding a comparatively high overhead.
…		…
206	If C<$enable> is false, then the C<encode> method will output key-value	259	If C<$enable> is false, then the C<encode> method will output key-value
207	pairs in the order Perl stores them (which will likely change between runs	260	pairs in the order Perl stores them (which will likely change between runs
208	of the same script).	261	of the same script).
209		262
210	This option is useful if you want the same data structure to be encoded as	263	This option is useful if you want the same data structure to be encoded as
211	the same JSON string (given the same overall settings). If it is disabled,	264	the same JSON text (given the same overall settings). If it is disabled,
212	the same hash migh be encoded differently even if contains the same data,	265	the same hash migh be encoded differently even if contains the same data,
213	as key-value pairs have no inherent ordering in Perl.	266	as key-value pairs have no inherent ordering in Perl.
214		267
215	This setting has no effect when decoding JSON strings.	268	This setting has no effect when decoding JSON texts.
216		269
217	=item $json = $json->allow_nonref ([$enable])	270	=item $json = $json->allow_nonref ([$enable])
218		271
219	If C<$enable> is true (or missing), then the C<encode> method can convert a	272	If C<$enable> is true (or missing), then the C<encode> method can convert a
220	non-reference into its corresponding string, number or null JSON value,	273	non-reference into its corresponding string, number or null JSON value,
221	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON	274	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON
222	values instead of croaking.	275	values instead of croaking.
223		276
224	If C<$enable> is false, then the C<encode> method will croak if it isn't	277	If C<$enable> is false, then the C<encode> method will croak if it isn't
225	passed an arrayref or hashref, as JSON strings must either be an object	278	passed an arrayref or hashref, as JSON texts must either be an object
226	or array. Likewise, C<decode> will croak if given something that is not a	279	or array. Likewise, C<decode> will croak if given something that is not a
227	JSON object or array.	280	JSON object or array.
228		281
		282	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,
		283	resulting in an invalid JSON text:
		284
		285	JSON::XS->new->allow_nonref->encode ("Hello, World!")
		286	=> "Hello, World!"
		287
229	=item $json = $json->shrink ([$enable])	288	=item $json = $json->shrink ([$enable])
230		289
231	Perl usually over-allocates memory a bit when allocating space for	290	Perl usually over-allocates memory a bit when allocating space for
232	strings. This flag optionally resizes strings generated by either	291	strings. This flag optionally resizes strings generated by either
233	C<encode> or C<decode> to their minimum size possible. This can save	292	C<encode> or C<decode> to their minimum size possible. This can save
234	memory when your JSON strings are either very very long or you have many	293	memory when your JSON texts are either very very long or you have many
235	short strings. It will also try to downgrade any strings to octet-form	294	short strings. It will also try to downgrade any strings to octet-form
236	if possible: perl stores strings internally either in an encoding called	295	if possible: perl stores strings internally either in an encoding called
237	UTF-X or in octet-form. The latter cannot store everything but uses less	296	UTF-X or in octet-form. The latter cannot store everything but uses less
238	space in general.	297	space in general (and some buggy Perl or C code might even rely on that
		298	internal representation being used).
239		299
		300	The actual definition of what shrink does might change in future versions,
		301	but it will always try to save space at the expense of time.
		302
240	If C<$enable> is true (or missing), the string returned by C<encode> will be shrunk-to-fit,	303	If C<$enable> is true (or missing), the string returned by C<encode> will
241	while all strings generated by C<decode> will also be shrunk-to-fit.	304	be shrunk-to-fit, while all strings generated by C<decode> will also be
		305	shrunk-to-fit.
242		306
243	If C<$enable> is false, then the normal perl allocation algorithms are used.	307	If C<$enable> is false, then the normal perl allocation algorithms are used.
244	If you work with your data, then this is likely to be faster.	308	If you work with your data, then this is likely to be faster.
245		309
246	In the future, this setting might control other things, such as converting	310	In the future, this setting might control other things, such as converting
247	strings that look like integers or floats into integers or floats	311	strings that look like integers or floats into integers or floats
248	internally (there is no difference on the Perl level), saving space.	312	internally (there is no difference on the Perl level), saving space.
249		313
		314	=item $json = $json->max_depth ([$maximum_nesting_depth])
		315
		316	Sets the maximum nesting level (default C<512>) accepted while encoding
		317	or decoding. If the JSON text or Perl data structure has an equal or
		318	higher nesting level then this limit, then the encoder and decoder will
		319	stop and croak at that point.
		320
		321	Nesting level is defined by number of hash- or arrayrefs that the encoder
		322	needs to traverse to reach a given point or the number of C<{> or C<[>
		323	characters without their matching closing parenthesis crossed to reach a
		324	given character in a string.
		325
		326	Setting the maximum depth to one disallows any nesting, so that ensures
		327	that the object is only a single hash/object or array.
		328
		329	The argument to C<max_depth> will be rounded up to the next nearest power
		330	of two.
		331
		332	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
		333
250	=item $json_string = $json->encode ($perl_scalar)	334	=item $json_text = $json->encode ($perl_scalar)
251		335
252	Converts the given Perl data structure (a simple scalar or a reference	336	Converts the given Perl data structure (a simple scalar or a reference
253	to a hash or array) to its JSON representation. Simple scalars will be	337	to a hash or array) to its JSON representation. Simple scalars will be
254	converted into JSON string or number sequences, while references to arrays	338	converted into JSON string or number sequences, while references to arrays
255	become JSON arrays and references to hashes become JSON objects. Undefined	339	become JSON arrays and references to hashes become JSON objects. Undefined
256	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>	340	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>
257	nor C<false> values will be generated.	341	nor C<false> values will be generated.
258		342
259	=item $perl_scalar = $json->decode ($json_string)	343	=item $perl_scalar = $json->decode ($json_text)
260		344
261	The opposite of C<encode>: expects a JSON string and tries to parse it,	345	The opposite of C<encode>: expects a JSON text and tries to parse it,
262	returning the resulting simple scalar or reference. Croaks on error.	346	returning the resulting simple scalar or reference. Croaks on error.
263		347
264	JSON numbers and strings become simple Perl scalars. JSON arrays become	348	JSON numbers and strings become simple Perl scalars. JSON arrays become
265	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes	349	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes
266	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.	350	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.
267		351
268	=back	352	=back
		353
269		354
270	=head1 MAPPING	355	=head1 MAPPING
271		356
272	This section describes how JSON::XS maps Perl values to JSON values and	357	This section describes how JSON::XS maps Perl values to JSON values and
273	vice versa. These mappings are designed to "do the right thing" in most	358	vice versa. These mappings are designed to "do the right thing" in most
…		…
283	=over 4	368	=over 4
284		369
285	=item object	370	=item object
286		371
287	A JSON object becomes a reference to a hash in Perl. No ordering of object	372	A JSON object becomes a reference to a hash in Perl. No ordering of object
288	keys is preserved.	373	keys is preserved (JSON does not preserver object key ordering itself).
289		374
290	=item array	375	=item array
291		376
292	A JSON array becomes a reference to an array in Perl.	377	A JSON array becomes a reference to an array in Perl.
293		378
…		…
327	=over 4	412	=over 4
328		413
329	=item hash references	414	=item hash references
330		415
331	Perl hash references become JSON objects. As there is no inherent ordering	416	Perl hash references become JSON objects. As there is no inherent ordering
332	in hash keys, they will usually be encoded in a pseudo-random order that	417	in hash keys (or JSON objects), they will usually be encoded in a
333	can change between runs of the same program but stays generally the same	418	pseudo-random order that can change between runs of the same program but
334	within the single run of a program. JSON::XS can optionally sort the hash	419	stays generally the same within a single run of a program. JSON::XS can
335	keys (determined by the I<canonical> flag), so the same datastructure	420	optionally sort the hash keys (determined by the I<canonical> flag), so
336	will serialise to the same JSON text (given same settings and version of	421	the same datastructure will serialise to the same JSON text (given same
337	JSON::XS), but this incurs a runtime overhead.	422	settings and version of JSON::XS), but this incurs a runtime overhead
		423	and is only rarely useful, e.g. when you want to compare some JSON text
		424	against another for equality.
338		425
339	=item array references	426	=item array references
340		427
341	Perl array references become JSON arrays.	428	Perl array references become JSON arrays.
		429
		430	=item other references
		431
		432	Other unblessed references are generally not allowed and will cause an
		433	exception to be thrown, except for references to the integers C<0> and
		434	C<1>, which get turned into C<false> and C<true> atoms in JSON. You can
		435	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.
		436
		437	to_json [\0,JSON::XS::true] # yields [false,true]
342		438
343	=item blessed objects	439	=item blessed objects
344		440
345	Blessed objects are not allowed. JSON::XS currently tries to encode their	441	Blessed objects are not allowed. JSON::XS currently tries to encode their
346	underlying representation (hash- or arrayref), but this behaviour might	442	underlying representation (hash- or arrayref), but this behaviour might
…		…
379	$x *= 1; # same thing, the choise is yours.	475	$x *= 1; # same thing, the choise is yours.
380		476
381	You can not currently output JSON booleans or force the type in other,	477	You can not currently output JSON booleans or force the type in other,
382	less obscure, ways. Tell me if you need this capability.	478	less obscure, ways. Tell me if you need this capability.
383		479
384	=item circular data structures
385
386	Those will be encoded until memory or stackspace runs out.
387
388	=back	480	=back
		481
389		482
390	=head1 COMPARISON	483	=head1 COMPARISON
391		484
392	As already mentioned, this module was created because none of the existing	485	As already mentioned, this module was created because none of the existing
393	JSON modules could be made to work correctly. First I will describe the	486	JSON modules could be made to work correctly. First I will describe the
…		…
419		512
420	Has problems handling many Perl values (e.g. regex results and other magic	513	Has problems handling many Perl values (e.g. regex results and other magic
421	values will make it croak).	514	values will make it croak).
422		515
423	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>	516	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>
424	which is not a valid JSON string.	517	which is not a valid JSON text.
425		518
426	Unmaintained (maintainer unresponsive for many months, bugs are not	519	Unmaintained (maintainer unresponsive for many months, bugs are not
427	getting fixed).	520	getting fixed).
428		521
429	=item JSON::Syck 0.21	522	=item JSON::Syck 0.21
…		…
431	Very buggy (often crashes).	524	Very buggy (often crashes).
432		525
433	Very inflexible (no human-readable format supported, format pretty much	526	Very inflexible (no human-readable format supported, format pretty much
434	undocumented. I need at least a format for easy reading by humans and a	527	undocumented. I need at least a format for easy reading by humans and a
435	single-line compact format for use in a protocol, and preferably a way to	528	single-line compact format for use in a protocol, and preferably a way to
436	generate ASCII-only JSON strings).	529	generate ASCII-only JSON texts).
437		530
438	Completely broken (and confusingly documented) Unicode handling (unicode	531	Completely broken (and confusingly documented) Unicode handling (unicode
439	escapes are not working properly, you need to set ImplicitUnicode to	532	escapes are not working properly, you need to set ImplicitUnicode to
440	I<different> values on en- and decoding to get symmetric behaviour).	533	I<different> values on en- and decoding to get symmetric behaviour).
441		534
…		…
464		557
465	Very inflexible.	558	Very inflexible.
466		559
467	No roundtripping.	560	No roundtripping.
468		561
469	Does not generate valid JSON (key strings are often unquoted, empty keys	562	Does not generate valid JSON texts (key strings are often unquoted, empty keys
470	result in nothing being output)	563	result in nothing being output)
471		564
472	Does not check input for validity.	565	Does not check input for validity.
473		566
474	=back	567	=back
…		…
478	It seems that JSON::XS is surprisingly fast, as shown in the following	571	It seems that JSON::XS is surprisingly fast, as shown in the following
479	tables. They have been generated with the help of the C<eg/bench> program	572	tables. They have been generated with the help of the C<eg/bench> program
480	in the JSON::XS distribution, to make it easy to compare on your own	573	in the JSON::XS distribution, to make it easy to compare on your own
481	system.	574	system.
482		575
483	First is a comparison between various modules using a very simple JSON	576	First comes a comparison between various modules using a very short JSON
		577	string:
		578
		579	{"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null}
		580
484	string, showing the number of encodes/decodes per second (JSON::XS is	581	It shows the number of encodes/decodes per second (JSON::XS uses the
485	the functional interface, while JSON::XS/2 is the OO interface with	582	functional interface, while JSON::XS/2 uses the OO interface with
486	pretty-printing and hashkey sorting enabled).	583	pretty-printing and hashkey sorting enabled). Higher is better:
487		584
488	module \| encode \| decode \|	585	module \| encode \| decode \|
489	-----------\|------------\|------------\|	586	-----------\|------------\|------------\|
490	JSON \| 14006 \| 6820 \|	587	JSON \| 11488.516 \| 7823.035 \|
491	JSON::DWIW \| 200937 \| 120386 \|	588	JSON::DWIW \| 94708.054 \| 129094.260 \|
492	JSON::PC \| 85065 \| 129366 \|	589	JSON::PC \| 63884.157 \| 128528.212 \|
493	JSON::Syck \| 59898 \| 44232 \|	590	JSON::Syck \| 34898.677 \| 42096.911 \|
494	JSON::XS \| 1171478 \| 342435 \|	591	JSON::XS \| 654027.064 \| 396423.669 \|
495	JSON::XS/2 \| 730760 \| 328714 \|	592	JSON::XS/2 \| 371564.190 \| 371725.613 \|
496	-----------+------------+------------+	593	-----------+------------+------------+
497		594
498	That is, JSON::XS is 6 times faster than than JSON::DWIW and about 80	595	That is, JSON::XS is more than six times faster than JSON::DWIW on
		596	encoding, more than three times faster on decoding, and about thirty times
499	times faster than JSON, even with pretty-printing and key sorting.	597	faster than JSON, even with pretty-printing and key sorting.
500		598
501	Using a longer test string (roughly 8KB, generated from Yahoo! Locals	599	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
502	search API (http://nanoref.com/yahooapis/mgPdGg):	600	search API (http://nanoref.com/yahooapis/mgPdGg):
503		601
504	module \| encode \| decode \|	602	module \| encode \| decode \|
505	-----------\|------------\|------------\|	603	-----------\|------------\|------------\|
506	JSON \| 673 \| 38 \|	604	JSON \| 273.023 \| 44.674 \|
507	JSON::DWIW \| 5271 \| 770 \|	605	JSON::DWIW \| 1089.383 \| 1145.704 \|
508	JSON::PC \| 9901 \| 2491 \|	606	JSON::PC \| 3097.419 \| 2393.921 \|
509	JSON::Syck \| 2360 \| 786 \|	607	JSON::Syck \| 514.060 \| 843.053 \|
510	JSON::XS \| 37398 \| 3202 \|	608	JSON::XS \| 6479.668 \| 3636.364 \|
511	JSON::XS/2 \| 13765 \| 3153 \|	609	JSON::XS/2 \| 3774.221 \| 3599.124 \|
512	-----------+------------+------------+	610	-----------+------------+------------+
513		611
514	Again, JSON::XS leads by far in the encoding case, while still beating	612	Again, JSON::XS leads by far.
515	every other module in the decoding case.
516		613
517	Last example is an almost 8MB large hash with many large binary values	614	On large strings containing lots of high unicode characters, some modules
518	(PNG files), resulting in a lot of escaping:	615	(such as JSON::PC) seem to decode faster than JSON::XS, but the result
		616	will be broken due to missing (or wrong) unicode handling. Others refuse
		617	to decode or encode properly, so it was impossible to prepare a fair
		618	comparison table for that case.
519		619
520	=head1 RESOURCE LIMITS
521		620
522	JSON::XS does not impose any limits on the size of JSON texts or Perl	621	=head1 SECURITY CONSIDERATIONS
523	values they represent - if your machine cna handle it, JSON::XS will	622
524	encode or decode it. Future versions might optionally impose structure	623	When you are using JSON in a protocol, talking to untrusted potentially
525	depth and memory use resource limits.	624	hostile creatures requires relatively few measures.
		625
		626	First of all, your JSON decoder should be secure, that is, should not have
		627	any buffer overflows. Obviously, this module should ensure that and I am
		628	trying hard on making that true, but you never know.
		629
		630	Second, you need to avoid resource-starving attacks. That means you should
		631	limit the size of JSON texts you accept, or make sure then when your
		632	resources run out, thats just fine (e.g. by using a separate process that
		633	can crash safely). The size of a JSON text in octets or characters is
		634	usually a good indication of the size of the resources required to decode
		635	it into a Perl structure.
		636
		637	Third, JSON::XS recurses using the C stack when decoding objects and
		638	arrays. The C stack is a limited resource: for instance, on my amd64
		639	machine with 8MB of stack size I can decode around 180k nested arrays but
		640	only 14k nested JSON objects (due to perl itself recursing deeply on croak
		641	to free the temporary). If that is exceeded, the program crashes. to be
		642	conservative, the default nesting limit is set to 512. If your process
		643	has a smaller stack, you should adjust this setting accordingly with the
		644	C<max_depth> method.
		645
		646	And last but least, something else could bomb you that I forgot to think
		647	of. In that case, you get to keep the pieces. I am always open for hints,
		648	though...
		649
526		650
527	=head1 BUGS	651	=head1 BUGS
528		652
529	While the goal of this module is to be correct, that unfortunately does	653	While the goal of this module is to be correct, that unfortunately does
530	not mean its bug-free, only that I think its design is bug-free. It is	654	not mean its bug-free, only that I think its design is bug-free. It is
531	still very young and not well-tested. If you keep reporting bugs they will	655	still relatively early in its development. If you keep reporting bugs they
532	be fixed swiftly, though.	656	will be fixed swiftly, though.
533		657
534	=cut	658	=cut
		659
		660	sub true() { \1 }
		661	sub false() { \0 }
535		662
536	1;	663	1;
537		664
538	=head1 AUTHOR	665	=head1 AUTHOR
539		666

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Comparing JSON-XS/XS.pm (file contents): Revision 1.11 by root, Fri Mar 23 17:48:59 2007 UTC vs. Revision 1.32 by root, Thu Apr 12 07:25:29 2007 UTC

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Comparing JSON-XS/XS.pm (file contents):
Revision 1.11 by root, Fri Mar 23 17:48:59 2007 UTC vs.
Revision 1.32 by root, Thu Apr 12 07:25:29 2007 UTC