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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.9 by root, Fri Mar 23 16:00:19 2007 UTC vs.
Revision 1.18 by root, Sat Mar 24 22:55:16 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, croak on error
		10
		11	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;
		12	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;
		13
		14	# oo-interface
		15
		16	$coder = JSON::XS->new->ascii->pretty->allow_nonref;
		17	$pretty_printed_unencoded = $coder->encode ($perl_scalar);
		18	$perl_scalar = $coder->decode ($unicode_json_text);
8		19
9	=head1 DESCRIPTION	20	=head1 DESCRIPTION
10		21
11	This module converts Perl data structures to JSON and vice versa. Its	22	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	23	primary goal is to be I<correct> and its secondary goal is to be
…		…
18	their maintainers are unresponsive, gone missing, or not listening to bug	29	their maintainers are unresponsive, gone missing, or not listening to bug
19	reports for other reasons.	30	reports for other reasons.
20		31
21	See COMPARISON, below, for a comparison to some other JSON modules.	32	See COMPARISON, below, for a comparison to some other JSON modules.
22		33
		34	See MAPPING, below, on how JSON::XS maps perl values to JSON values and
		35	vice versa.
		36
23	=head2 FEATURES	37	=head2 FEATURES
24		38
25	=over 4	39	=over 4
26		40
27	=item * correct handling of unicode issues	41	=item * correct handling of unicode issues
28		42
29	This module knows how to handle Unicode, and even documents how it does so.	43	This module knows how to handle Unicode, and even documents how and when
		44	it does so.
30		45
31	=item * round-trip integrity	46	=item * round-trip integrity
32		47
33	When you serialise a perl data structure using only datatypes supported	48	When you serialise a perl data structure using only datatypes supported
34	by JSON, the deserialised data structure is identical on the Perl level.	49	by JSON, the deserialised data structure is identical on the Perl level.
35	(e.g. the string "2.0" doesn't suddenly become "2").	50	(e.g. the string "2.0" doesn't suddenly become "2").
36		51
37	=item * strict checking of JSON correctness	52	=item * strict checking of JSON correctness
38		53
39	There is no guessing, no generating of illegal JSON strings by default,	54	There is no guessing, no generating of illegal JSON texts by default,
40	and only JSON is accepted as input (the latter is a security feature).	55	and only JSON is accepted as input by default (the latter is a security
		56	feature).
41		57
42	=item * fast	58	=item * fast
43		59
44	compared to other JSON modules, this module compares favourably.	60	Compared to other JSON modules, this module compares favourably in terms
		61	of speed, too.
45		62
46	=item * simple to use	63	=item * simple to use
47		64
48	This module has both a simple functional interface as well as an OO	65	This module has both a simple functional interface as well as an OO
49	interface.	66	interface.
50		67
51	=item * reasonably versatile output formats	68	=item * reasonably versatile output formats
52		69
53	You can choose between the most compact format possible, a pure-ascii	70	You can choose between the most compact guarenteed single-line format
54	format, or a pretty-printed format. Or you can combine those features in	71	possible (nice for simple line-based protocols), a pure-ascii format (for
		72	when your transport is not 8-bit clean), or a pretty-printed format (for
		73	when you want to read that stuff). Or you can combine those features in
55	whatever way you like.	74	whatever way you like.
56		75
57	=back	76	=back
58		77
59	=cut	78	=cut
60		79
61	package JSON::XS;	80	package JSON::XS;
62		81
63	BEGIN {	82	BEGIN {
64	$VERSION = '0.3';	83	$VERSION = '0.5';
65	@ISA = qw(Exporter);	84	@ISA = qw(Exporter);
66		85
67	@EXPORT = qw(to_json from_json);	86	@EXPORT = qw(to_json from_json);
68	require Exporter;	87	require Exporter;
69		88
…		…
76	The following convinience methods are provided by this module. They are	95	The following convinience methods are provided by this module. They are
77	exported by default:	96	exported by default:
78		97
79	=over 4	98	=over 4
80		99
81	=item $json_string = to_json $perl_scalar	100	=item $json_text = to_json $perl_scalar
82		101
83	Converts the given Perl data structure (a simple scalar or a reference to	102	Converts the given Perl data structure (a simple scalar or a reference to
84	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains	103	a hash or array) to a UTF-8 encoded, binary string (that is, the string contains
85	octets only). Croaks on error.	104	octets only). Croaks on error.
86		105
87	This function call is functionally identical to C<< JSON::XS->new->utf8	106	This function call is functionally identical to:
88	(1)->encode ($perl_scalar) >>.
89		107
		108	$json_text = JSON::XS->new->utf8->encode ($perl_scalar)
		109
		110	except being faster.
		111
90	=item $perl_scalar = from_json $json_string	112	=item $perl_scalar = from_json $json_text
91		113
92	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to	114	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to
93	parse that as an UTF-8 encoded JSON string, returning the resulting simple	115	parse that as an UTF-8 encoded JSON text, returning the resulting simple
94	scalar or reference. Croaks on error.	116	scalar or reference. Croaks on error.
95		117
96	This function call is functionally identical to C<< JSON::XS->new->utf8	118	This function call is functionally identical to:
97	(1)->decode ($json_string) >>.	119
		120	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)
		121
		122	except being faster.
98		123
99	=back	124	=back
100		125
101	=head1 OBJECT-ORIENTED INTERFACE	126	=head1 OBJECT-ORIENTED INTERFACE
102		127
…		…
111	strings. All boolean flags described below are by default I<disabled>.	136	strings. All boolean flags described below are by default I<disabled>.
112		137
113	The mutators for flags all return the JSON object again and thus calls can	138	The mutators for flags all return the JSON object again and thus calls can
114	be chained:	139	be chained:
115		140
116	my $json = JSON::XS->new->utf8(1)->space_after(1)->encode ({a => [1,2]})	141	my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]})
117	=> {"a": [1, 2]}	142	=> {"a": [1, 2]}
118		143
119	=item $json = $json->ascii ([$enable])	144	=item $json = $json->ascii ([$enable])
120		145
121	If C<$enable> is true (or missing), then the C<encode> method will	146	If C<$enable> is true (or missing), then the C<encode> method will not
122	not generate characters outside the code range C<0..127>. Any unicode	147	generate characters outside the code range C<0..127> (which is ASCII). Any
123	characters outside that range will be escaped using either a single	148	unicode characters outside that range will be escaped using either a
124	\uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, as per	149	single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence,
125	RFC4627.	150	as per RFC4627.
126		151
127	If C<$enable> is false, then the C<encode> method will not escape Unicode	152	If C<$enable> is false, then the C<encode> method will not escape Unicode
128	characters unless necessary.	153	characters unless required by the JSON syntax. This results in a faster
		154	and more compact format.
129		155
130	JSON::XS->new->ascii (1)->encode (chr 0x10401)	156	JSON::XS->new->ascii (1)->encode ([chr 0x10401])
131	=> \ud801\udc01	157	=> ["\ud801\udc01"]
132		158
133	=item $json = $json->utf8 ([$enable])	159	=item $json = $json->utf8 ([$enable])
134		160
135	If C<$enable> is true (or missing), then the C<encode> method will encode	161	If C<$enable> is true (or missing), then the C<encode> method will encode
136	the JSON string into UTF-8, as required by many protocols, while the	162	the JSON result into UTF-8, as required by many protocols, while the
137	C<decode> method expects to be handled an UTF-8-encoded string. Please	163	C<decode> method expects to be handled an UTF-8-encoded string. Please
138	note that UTF-8-encoded strings do not contain any characters outside the	164	note that UTF-8-encoded strings do not contain any characters outside the
139	range C<0..255>, they are thus useful for bytewise/binary I/O.	165	range C<0..255>, they are thus useful for bytewise/binary I/O. In future
		166	versions, enabling this option might enable autodetection of the UTF-16
		167	and UTF-32 encoding families, as described in RFC4627.
140		168
141	If C<$enable> is false, then the C<encode> method will return the JSON	169	If C<$enable> is false, then the C<encode> method will return the JSON
142	string as a (non-encoded) unicode string, while C<decode> expects thus a	170	string as a (non-encoded) unicode string, while C<decode> expects thus a
143	unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs	171	unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs
144	to be done yourself, e.g. using the Encode module.	172	to be done yourself, e.g. using the Encode module.
145		173
		174	Example, output UTF-16BE-encoded JSON:
		175
		176	use Encode;
		177	$jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object);
		178
		179	Example, decode UTF-32LE-encoded JSON:
		180
		181	use Encode;
		182	$object = JSON::XS->new->decode (decode "UTF-32LE", $jsontext);
		183
146	=item $json = $json->pretty ([$enable])	184	=item $json = $json->pretty ([$enable])
147		185
148	This enables (or disables) all of the C<indent>, C<space_before> and	186	This enables (or disables) all of the C<indent>, C<space_before> and
149	C<space_after> (and in the future possibly more) flags in one call to	187	C<space_after> (and in the future possibly more) flags in one call to
150	generate the most readable (or most compact) form possible.	188	generate the most readable (or most compact) form possible.
		189
		190	Example, pretty-print some simple structure:
151		191
152	my $json = JSON::XS->new->pretty(1)->encode ({a => [1,2]})	192	my $json = JSON::XS->new->pretty(1)->encode ({a => [1,2]})
153	=>	193	=>
154	{	194	{
155	"a" : [	195	"a" : [
…		…
163	If C<$enable> is true (or missing), then the C<encode> method will use a multiline	203	If C<$enable> is true (or missing), then the C<encode> method will use a multiline
164	format as output, putting every array member or object/hash key-value pair	204	format as output, putting every array member or object/hash key-value pair
165	into its own line, identing them properly.	205	into its own line, identing them properly.
166		206
167	If C<$enable> is false, no newlines or indenting will be produced, and the	207	If C<$enable> is false, no newlines or indenting will be produced, and the
168	resulting JSON strings is guarenteed not to contain any C<newlines>.	208	resulting JSON text is guarenteed not to contain any C<newlines>.
169		209
170	This setting has no effect when decoding JSON strings.	210	This setting has no effect when decoding JSON texts.
171		211
172	=item $json = $json->space_before ([$enable])	212	=item $json = $json->space_before ([$enable])
173		213
174	If C<$enable> is true (or missing), then the C<encode> method will add an extra	214	If C<$enable> is true (or missing), then the C<encode> method will add an extra
175	optional space before the C<:> separating keys from values in JSON objects.	215	optional space before the C<:> separating keys from values in JSON objects.
176		216
177	If C<$enable> is false, then the C<encode> method will not add any extra	217	If C<$enable> is false, then the C<encode> method will not add any extra
178	space at those places.	218	space at those places.
179		219
180	This setting has no effect when decoding JSON strings. You will also most	220	This setting has no effect when decoding JSON texts. You will also
181	likely combine this setting with C<space_after>.	221	most likely combine this setting with C<space_after>.
		222
		223	Example, space_before enabled, space_after and indent disabled:
		224
		225	{"key" :"value"}
182		226
183	=item $json = $json->space_after ([$enable])	227	=item $json = $json->space_after ([$enable])
184		228
185	If C<$enable> is true (or missing), then the C<encode> method will add an extra	229	If C<$enable> is true (or missing), then the C<encode> method will add an extra
186	optional space after the C<:> separating keys from values in JSON objects	230	optional space after the C<:> separating keys from values in JSON objects
…		…
188	members.	232	members.
189		233
190	If C<$enable> is false, then the C<encode> method will not add any extra	234	If C<$enable> is false, then the C<encode> method will not add any extra
191	space at those places.	235	space at those places.
192		236
193	This setting has no effect when decoding JSON strings.	237	This setting has no effect when decoding JSON texts.
		238
		239	Example, space_before and indent disabled, space_after enabled:
		240
		241	{"key": "value"}
194		242
195	=item $json = $json->canonical ([$enable])	243	=item $json = $json->canonical ([$enable])
196		244
197	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects	245	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
198	by sorting their keys. This is adding a comparatively high overhead.	246	by sorting their keys. This is adding a comparatively high overhead.
…		…
200	If C<$enable> is false, then the C<encode> method will output key-value	248	If C<$enable> is false, then the C<encode> method will output key-value
201	pairs in the order Perl stores them (which will likely change between runs	249	pairs in the order Perl stores them (which will likely change between runs
202	of the same script).	250	of the same script).
203		251
204	This option is useful if you want the same data structure to be encoded as	252	This option is useful if you want the same data structure to be encoded as
205	the same JSON string (given the same overall settings). If it is disabled,	253	the same JSON text (given the same overall settings). If it is disabled,
206	the same hash migh be encoded differently even if contains the same data,	254	the same hash migh be encoded differently even if contains the same data,
207	as key-value pairs have no inherent ordering in Perl.	255	as key-value pairs have no inherent ordering in Perl.
208		256
209	This setting has no effect when decoding JSON strings.	257	This setting has no effect when decoding JSON texts.
210		258
211	=item $json = $json->allow_nonref ([$enable])	259	=item $json = $json->allow_nonref ([$enable])
212		260
213	If C<$enable> is true (or missing), then the C<encode> method can convert a	261	If C<$enable> is true (or missing), then the C<encode> method can convert a
214	non-reference into its corresponding string, number or null JSON value,	262	non-reference into its corresponding string, number or null JSON value,
215	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON	263	which is an extension to RFC4627. Likewise, C<decode> will accept those JSON
216	values instead of croaking.	264	values instead of croaking.
217		265
218	If C<$enable> is false, then the C<encode> method will croak if it isn't	266	If C<$enable> is false, then the C<encode> method will croak if it isn't
219	passed an arrayref or hashref, as JSON strings must either be an object	267	passed an arrayref or hashref, as JSON texts must either be an object
220	or array. Likewise, C<decode> will croak if given something that is not a	268	or array. Likewise, C<decode> will croak if given something that is not a
221	JSON object or array.	269	JSON object or array.
		270
		271	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,
		272	resulting in an invalid JSON text:
		273
		274	JSON::XS->new->allow_nonref->encode ("Hello, World!")
		275	=> "Hello, World!"
222		276
223	=item $json = $json->shrink ([$enable])	277	=item $json = $json->shrink ([$enable])
224		278
225	Perl usually over-allocates memory a bit when allocating space for	279	Perl usually over-allocates memory a bit when allocating space for
226	strings. This flag optionally resizes strings generated by either	280	strings. This flag optionally resizes strings generated by either
227	C<encode> or C<decode> to their minimum size possible. This can save	281	C<encode> or C<decode> to their minimum size possible. This can save
228	memory when your JSON strings are either very very long or you have many	282	memory when your JSON texts are either very very long or you have many
229	short strings. It will also try to downgrade any strings to octet-form	283	short strings. It will also try to downgrade any strings to octet-form
230	if possible: perl stores strings internally either in an encoding called	284	if possible: perl stores strings internally either in an encoding called
231	UTF-X or in octet-form. The latter cannot store everything but uses less	285	UTF-X or in octet-form. The latter cannot store everything but uses less
232	space in general.	286	space in general.
233		287
…		…
239		293
240	In the future, this setting might control other things, such as converting	294	In the future, this setting might control other things, such as converting
241	strings that look like integers or floats into integers or floats	295	strings that look like integers or floats into integers or floats
242	internally (there is no difference on the Perl level), saving space.	296	internally (there is no difference on the Perl level), saving space.
243		297
244	=item $json_string = $json->encode ($perl_scalar)	298	=item $json_text = $json->encode ($perl_scalar)
245		299
246	Converts the given Perl data structure (a simple scalar or a reference	300	Converts the given Perl data structure (a simple scalar or a reference
247	to a hash or array) to its JSON representation. Simple scalars will be	301	to a hash or array) to its JSON representation. Simple scalars will be
248	converted into JSON string or number sequences, while references to arrays	302	converted into JSON string or number sequences, while references to arrays
249	become JSON arrays and references to hashes become JSON objects. Undefined	303	become JSON arrays and references to hashes become JSON objects. Undefined
250	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>	304	Perl values (e.g. C<undef>) become JSON C<null> values. Neither C<true>
251	nor C<false> values will be generated.	305	nor C<false> values will be generated.
252		306
253	=item $perl_scalar = $json->decode ($json_string)	307	=item $perl_scalar = $json->decode ($json_text)
254		308
255	The opposite of C<encode>: expects a JSON string and tries to parse it,	309	The opposite of C<encode>: expects a JSON text and tries to parse it,
256	returning the resulting simple scalar or reference. Croaks on error.	310	returning the resulting simple scalar or reference. Croaks on error.
257		311
258	JSON numbers and strings become simple Perl scalars. JSON arrays become	312	JSON numbers and strings become simple Perl scalars. JSON arrays become
259	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes	313	Perl arrayrefs and JSON objects become Perl hashrefs. C<true> becomes
260	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.	314	C<1>, C<false> becomes C<0> and C<null> becomes C<undef>.
		315
		316	=back
		317
		318	=head1 MAPPING
		319
		320	This section describes how JSON::XS maps Perl values to JSON values and
		321	vice versa. These mappings are designed to "do the right thing" in most
		322	circumstances automatically, preserving round-tripping characteristics
		323	(what you put in comes out as something equivalent).
		324
		325	For the more enlightened: note that in the following descriptions,
		326	lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl>
		327	refers to the abstract Perl language itself.
		328
		329	=head2 JSON -> PERL
		330
		331	=over 4
		332
		333	=item object
		334
		335	A JSON object becomes a reference to a hash in Perl. No ordering of object
		336	keys is preserved (JSON does not preserver object key ordering itself).
		337
		338	=item array
		339
		340	A JSON array becomes a reference to an array in Perl.
		341
		342	=item string
		343
		344	A JSON string becomes a string scalar in Perl - Unicode codepoints in JSON
		345	are represented by the same codepoints in the Perl string, so no manual
		346	decoding is necessary.
		347
		348	=item number
		349
		350	A JSON number becomes either an integer or numeric (floating point)
		351	scalar in perl, depending on its range and any fractional parts. On the
		352	Perl level, there is no difference between those as Perl handles all the
		353	conversion details, but an integer may take slightly less memory and might
		354	represent more values exactly than (floating point) numbers.
		355
		356	=item true, false
		357
		358	These JSON atoms become C<0>, C<1>, respectively. Information is lost in
		359	this process. Future versions might represent those values differently,
		360	but they will be guarenteed to act like these integers would normally in
		361	Perl.
		362
		363	=item null
		364
		365	A JSON null atom becomes C<undef> in Perl.
		366
		367	=back
		368
		369	=head2 PERL -> JSON
		370
		371	The mapping from Perl to JSON is slightly more difficult, as Perl is a
		372	truly typeless language, so we can only guess which JSON type is meant by
		373	a Perl value.
		374
		375	=over 4
		376
		377	=item hash references
		378
		379	Perl hash references become JSON objects. As there is no inherent ordering
		380	in hash keys, they will usually be encoded in a pseudo-random order that
		381	can change between runs of the same program but stays generally the same
		382	within a single run of a program. JSON::XS can optionally sort the hash
		383	keys (determined by the I<canonical> flag), so the same datastructure
		384	will serialise to the same JSON text (given same settings and version of
		385	JSON::XS), but this incurs a runtime overhead.
		386
		387	=item array references
		388
		389	Perl array references become JSON arrays.
		390
		391	=item blessed objects
		392
		393	Blessed objects are not allowed. JSON::XS currently tries to encode their
		394	underlying representation (hash- or arrayref), but this behaviour might
		395	change in future versions.
		396
		397	=item simple scalars
		398
		399	Simple Perl scalars (any scalar that is not a reference) are the most
		400	difficult objects to encode: JSON::XS will encode undefined scalars as
		401	JSON null value, scalars that have last been used in a string context
		402	before encoding as JSON strings and anything else as number value:
		403
		404	# dump as number
		405	to_json [2] # yields [2]
		406	to_json [-3.0e17] # yields [-3e+17]
		407	my $value = 5; to_json [$value] # yields [5]
		408
		409	# used as string, so dump as string
		410	print $value;
		411	to_json [$value] # yields ["5"]
		412
		413	# undef becomes null
		414	to_json [undef] # yields [null]
		415
		416	You can force the type to be a string by stringifying it:
		417
		418	my $x = 3.1; # some variable containing a number
		419	"$x"; # stringified
		420	$x .= ""; # another, more awkward way to stringify
		421	print $x; # perl does it for you, too, quite often
		422
		423	You can force the type to be a number by numifying it:
		424
		425	my $x = "3"; # some variable containing a string
		426	$x += 0; # numify it, ensuring it will be dumped as a number
		427	$x *= 1; # same thing, the choise is yours.
		428
		429	You can not currently output JSON booleans or force the type in other,
		430	less obscure, ways. Tell me if you need this capability.
		431
		432	=item circular data structures
		433
		434	Those will be encoded until memory or stackspace runs out.
261		435
262	=back	436	=back
263		437
264	=head1 COMPARISON	438	=head1 COMPARISON
265		439
…		…
293		467
294	Has problems handling many Perl values (e.g. regex results and other magic	468	Has problems handling many Perl values (e.g. regex results and other magic
295	values will make it croak).	469	values will make it croak).
296		470
297	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>	471	Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}>
298	which is not a valid JSON string.	472	which is not a valid JSON text.
299		473
300	Unmaintained (maintainer unresponsive for many months, bugs are not	474	Unmaintained (maintainer unresponsive for many months, bugs are not
301	getting fixed).	475	getting fixed).
302		476
303	=item JSON::Syck 0.21	477	=item JSON::Syck 0.21
…		…
305	Very buggy (often crashes).	479	Very buggy (often crashes).
306		480
307	Very inflexible (no human-readable format supported, format pretty much	481	Very inflexible (no human-readable format supported, format pretty much
308	undocumented. I need at least a format for easy reading by humans and a	482	undocumented. I need at least a format for easy reading by humans and a
309	single-line compact format for use in a protocol, and preferably a way to	483	single-line compact format for use in a protocol, and preferably a way to
310	generate ASCII-only JSON strings).	484	generate ASCII-only JSON texts).
311		485
312	Completely broken (and confusingly documented) Unicode handling (unicode	486	Completely broken (and confusingly documented) Unicode handling (unicode
313	escapes are not working properly, you need to set ImplicitUnicode to	487	escapes are not working properly, you need to set ImplicitUnicode to
314	I<different> values on en- and decoding to get symmetric behaviour).	488	I<different> values on en- and decoding to get symmetric behaviour).
315		489
…		…
338		512
339	Very inflexible.	513	Very inflexible.
340		514
341	No roundtripping.	515	No roundtripping.
342		516
343	Does not generate valid JSON (key strings are often unquoted, empty keys	517	Does not generate valid JSON texts (key strings are often unquoted, empty keys
344	result in nothing being output)	518	result in nothing being output)
345		519
346	Does not check input for validity.	520	Does not check input for validity.
347		521
348	=back	522	=back
…		…
352	It seems that JSON::XS is surprisingly fast, as shown in the following	526	It seems that JSON::XS is surprisingly fast, as shown in the following
353	tables. They have been generated with the help of the C<eg/bench> program	527	tables. They have been generated with the help of the C<eg/bench> program
354	in the JSON::XS distribution, to make it easy to compare on your own	528	in the JSON::XS distribution, to make it easy to compare on your own
355	system.	529	system.
356		530
357	First is a comparison between various modules using a very simple JSON	531	First comes a comparison between various modules using a very short JSON
		532	string:
		533
		534	{"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null}
		535
358	string, showing the number of encodes/decodes per second (JSON::XS is	536	It shows the number of encodes/decodes per second (JSON::XS uses the
359	the functional interface, while JSON::XS/2 is the OO interface with	537	functional interface, while JSON::XS/2 uses the OO interface with
360	pretty-printing and hashkey sorting enabled).	538	pretty-printing and hashkey sorting enabled). Higher is better:
361		539
362	module \| encode \| decode \|	540	module \| encode \| decode \|
363	-----------\|------------\|------------\|	541	-----------\|------------\|------------\|
364	JSON \| 14006 \| 6820 \|	542	JSON \| 11488.516 \| 7823.035 \|
365	JSON::DWIW \| 200937 \| 120386 \|	543	JSON::DWIW \| 94708.054 \| 129094.260 \|
366	JSON::PC \| 85065 \| 129366 \|	544	JSON::PC \| 63884.157 \| 128528.212 \|
367	JSON::Syck \| 59898 \| 44232 \|	545	JSON::Syck \| 34898.677 \| 42096.911 \|
368	JSON::XS \| 1171478 \| 342435 \|	546	JSON::XS \| 654027.064 \| 396423.669 \|
369	JSON::XS/2 \| 730760 \| 328714 \|	547	JSON::XS/2 \| 371564.190 \| 371725.613 \|
370	-----------+------------+------------+	548	-----------+------------+------------+
371		549
372	That is, JSON::XS is 6 times faster than than JSON::DWIW and about 80	550	That is, JSON::XS is more than six times faster than JSON::DWIW on
		551	encoding, more than three times faster on decoding, and about thirty times
373	times faster than JSON, even with pretty-printing and key sorting.	552	faster than JSON, even with pretty-printing and key sorting.
374		553
375	Using a longer test string (roughly 8KB, generated from Yahoo! Locals	554	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
376	search API (http://nanoref.com/yahooapis/mgPdGg):	555	search API (http://nanoref.com/yahooapis/mgPdGg):
377		556
378	module \| encode \| decode \|	557	module \| encode \| decode \|
379	-----------\|------------\|------------\|	558	-----------\|------------\|------------\|
380	JSON \| 673 \| 38 \|	559	JSON \| 273.023 \| 44.674 \|
381	JSON::DWIW \| 5271 \| 770 \|	560	JSON::DWIW \| 1089.383 \| 1145.704 \|
382	JSON::PC \| 9901 \| 2491 \|	561	JSON::PC \| 3097.419 \| 2393.921 \|
383	JSON::Syck \| 2360 \| 786 \|	562	JSON::Syck \| 514.060 \| 843.053 \|
384	JSON::XS \| 37398 \| 3202 \|	563	JSON::XS \| 6479.668 \| 3636.364 \|
385	JSON::XS/2 \| 13765 \| 3153 \|	564	JSON::XS/2 \| 3774.221 \| 3599.124 \|
386	-----------+------------+------------+	565	-----------+------------+------------+
387		566
388	Again, JSON::XS leads by far in the encoding case, while still beating	567	Again, JSON::XS leads by far.
389	every other module in the decoding case.
390		568
391	Last example is an almost 8MB large hash with many large binary values	569	On large strings containing lots of high unicode characters, some modules
392	(PNG files), resulting in a lot of escaping:	570	(such as JSON::PC) seem to decode faster than JSON::XS, but the result
		571	will be broken due to missing (or wrong) unicode handling. Others refuse
		572	to decode or encode properly, so it was impossible to prepare a fair
		573	comparison table for that case.
		574
		575	=head1 RESOURCE LIMITS
		576
		577	JSON::XS does not impose any limits on the size of JSON texts or Perl
		578	values they represent - if your machine can handle it, JSON::XS will
		579	encode or decode it. Future versions might optionally impose structure
		580	depth and memory use resource limits.
393		581
394	=head1 BUGS	582	=head1 BUGS
395		583
396	While the goal of this module is to be correct, that unfortunately does	584	While the goal of this module is to be correct, that unfortunately does
397	not mean its bug-free, only that I think its design is bug-free. It is	585	not mean its bug-free, only that I think its design is bug-free. It is

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing JSON-XS/XS.pm (file contents): Revision 1.9 by root, Fri Mar 23 16:00:19 2007 UTC vs. Revision 1.18 by root, Sat Mar 24 22:55:16 2007 UTC

Diff Legend

Comparing JSON-XS/XS.pm (file contents):
Revision 1.9 by root, Fri Mar 23 16:00:19 2007 UTC vs.
Revision 1.18 by root, Sat Mar 24 22:55:16 2007 UTC