[ViewVC] Diff of: cvs/JSON-XS/README

Comparing JSON-XS/README (file contents):
Revision 1.9 by root, Thu Mar 29 02:45:49 2007 UTC vs.
Revision 1.18 by root, Tue Aug 28 02:06:06 2007 UTC

…		…
7	# exported functions, they croak on error	7	# exported functions, they croak on error
8	# and expect/generate UTF-8	8	# and expect/generate UTF-8
9		9
10	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;	10	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;
11	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;	11	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;
12
13	# objToJson and jsonToObj aliases to to_json and from_json
14	# are exported for compatibility to the JSON module,
15	# but should not be used in new code.
16		12
17	# OO-interface	13	# OO-interface
18		14
19	$coder = JSON::XS->new->ascii->pretty->allow_nonref;	15	$coder = JSON::XS->new->ascii->pretty->allow_nonref;
20	$pretty_printed_unencoded = $coder->encode ($perl_scalar);	16	$pretty_printed_unencoded = $coder->encode ($perl_scalar);
…		…
92		88
93	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)	89	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)
94		90
95	except being faster.	91	except being faster.
96		92
		93	$is_boolean = JSON::XS::is_bool $scalar
		94	Returns true if the passed scalar represents either JSON::XS::true
		95	or JSON::XS::false, two constants that act like 1 and 0,
		96	respectively and are used to represent JSON "true" and "false"
		97	values in Perl.
		98
		99	See MAPPING, below, for more information on how JSON values are
		100	mapped to Perl.
		101
97	OBJECT-ORIENTED INTERFACE	102	OBJECT-ORIENTED INTERFACE
98	The object oriented interface lets you configure your own encoding or	103	The object oriented interface lets you configure your own encoding or
99	decoding style, within the limits of supported formats.	104	decoding style, within the limits of supported formats.
100		105
101	$json = new JSON::XS	106	$json = new JSON::XS
…		…
112	$json = $json->ascii ([$enable])	117	$json = $json->ascii ([$enable])
113	If $enable is true (or missing), then the "encode" method will not	118	If $enable is true (or missing), then the "encode" method will not
114	generate characters outside the code range 0..127 (which is ASCII).	119	generate characters outside the code range 0..127 (which is ASCII).
115	Any unicode characters outside that range will be escaped using	120	Any unicode characters outside that range will be escaped using
116	either a single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL	121	either a single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL
117	escape sequence, as per RFC4627.	122	escape sequence, as per RFC4627. The resulting encoded JSON text can
		123	be treated as a native unicode string, an ascii-encoded,
		124	latin1-encoded or UTF-8 encoded string, or any other superset of
		125	ASCII.
118		126
119	If $enable is false, then the "encode" method will not escape	127	If $enable is false, then the "encode" method will not escape
120	Unicode characters unless required by the JSON syntax. This results	128	Unicode characters unless required by the JSON syntax or other
121	in a faster and more compact format.	129	flags. This results in a faster and more compact format.
		130
		131	The main use for this flag is to produce JSON texts that can be
		132	transmitted over a 7-bit channel, as the encoded JSON texts will not
		133	contain any 8 bit characters.
122		134
123	JSON::XS->new->ascii (1)->encode ([chr 0x10401])	135	JSON::XS->new->ascii (1)->encode ([chr 0x10401])
124	=> ["\ud801\udc01"]	136	=> ["\ud801\udc01"]
		137
		138	$json = $json->latin1 ([$enable])
		139	If $enable is true (or missing), then the "encode" method will
		140	encode the resulting JSON text as latin1 (or iso-8859-1), escaping
		141	any characters outside the code range 0..255. The resulting string
		142	can be treated as a latin1-encoded JSON text or a native unicode
		143	string. The "decode" method will not be affected in any way by this
		144	flag, as "decode" by default expects unicode, which is a strict
		145	superset of latin1.
		146
		147	If $enable is false, then the "encode" method will not escape
		148	Unicode characters unless required by the JSON syntax or other
		149	flags.
		150
		151	The main use for this flag is efficiently encoding binary data as
		152	JSON text, as most octets will not be escaped, resulting in a
		153	smaller encoded size. The disadvantage is that the resulting JSON
		154	text is encoded in latin1 (and must correctly be treated as such
		155	when storing and transfering), a rare encoding for JSON. It is
		156	therefore most useful when you want to store data structures known
		157	to contain binary data efficiently in files or databases, not when
		158	talking to other JSON encoders/decoders.
		159
		160	JSON::XS->new->latin1->encode (["\x{89}\x{abc}"]
		161	=> ["\x{89}\\u0abc"] # (perl syntax, U+abc escaped, U+89 not)
125		162
126	$json = $json->utf8 ([$enable])	163	$json = $json->utf8 ([$enable])
127	If $enable is true (or missing), then the "encode" method will	164	If $enable is true (or missing), then the "encode" method will
128	encode the JSON result into UTF-8, as required by many protocols,	165	encode the JSON result into UTF-8, as required by many protocols,
129	while the "decode" method expects to be handled an UTF-8-encoded	166	while the "decode" method expects to be handled an UTF-8-encoded
…		…
203		240
204	Example, space_before and indent disabled, space_after enabled:	241	Example, space_before and indent disabled, space_after enabled:
205		242
206	{"key": "value"}	243	{"key": "value"}
207		244
		245	$json = $json->relaxed ([$enable])
		246	If $enable is true (or missing), then "decode" will accept some
		247	extensions to normal JSON syntax (see below). "encode" will not be
		248	affected in anyway. *Be aware that this option makes you accept
		249	invalid JSON texts as if they were valid!*. I suggest only to use
		250	this option to parse application-specific files written by humans
		251	(configuration files, resource files etc.)
		252
		253	If $enable is false (the default), then "decode" will only accept
		254	valid JSON texts.
		255
		256	Currently accepted extensions are:
		257
		258	* list items can have an end-comma
		259	JSON separates array elements and key-value pairs with commas.
		260	This can be annoying if you write JSON texts manually and want
		261	to be able to quickly append elements, so this extension accepts
		262	comma at the end of such items not just between them:
		263
		264	[
		265	1,
		266	2, <- this comma not normally allowed
		267	]
		268	{
		269	"k1": "v1",
		270	"k2": "v2", <- this comma not normally allowed
		271	}
		272
		273	* shell-style '#'-comments
		274	Whenever JSON allows whitespace, shell-style comments are
		275	additionally allowed. They are terminated by the first
		276	carriage-return or line-feed character, after which more
		277	white-space and comments are allowed.
		278
		279	[
		280	1, # this comment not allowed in JSON
		281	# neither this one...
		282	]
		283
208	$json = $json->canonical ([$enable])	284	$json = $json->canonical ([$enable])
209	If $enable is true (or missing), then the "encode" method will	285	If $enable is true (or missing), then the "encode" method will
210	output JSON objects by sorting their keys. This is adding a	286	output JSON objects by sorting their keys. This is adding a
211	comparatively high overhead.	287	comparatively high overhead.
212		288
…		…
236	Example, encode a Perl scalar as JSON value with enabled	312	Example, encode a Perl scalar as JSON value with enabled
237	"allow_nonref", resulting in an invalid JSON text:	313	"allow_nonref", resulting in an invalid JSON text:
238		314
239	JSON::XS->new->allow_nonref->encode ("Hello, World!")	315	JSON::XS->new->allow_nonref->encode ("Hello, World!")
240	=> "Hello, World!"	316	=> "Hello, World!"
		317
		318	$json = $json->allow_blessed ([$enable])
		319	If $enable is true (or missing), then the "encode" method will not
		320	barf when it encounters a blessed reference. Instead, the value of
		321	the convert_blessed option will decide wether "null"
		322	("convert_blessed" disabled or no "to_json" method found) or a
		323	representation of the object ("convert_blessed" enabled and
		324	"to_json" method found) is being encoded. Has no effect on "decode".
		325
		326	If $enable is false (the default), then "encode" will throw an
		327	exception when it encounters a blessed object.
		328
		329	$json = $json->convert_blessed ([$enable])
		330	If $enable is true (or missing), then "encode", upon encountering a
		331	blessed object, will check for the availability of the "TO_JSON"
		332	method on the object's class. If found, it will be called in scalar
		333	context and the resulting scalar will be encoded instead of the
		334	object. If no "TO_JSON" method is found, the value of
		335	"allow_blessed" will decide what to do.
		336
		337	The "TO_JSON" method may safely call die if it wants. If "TO_JSON"
		338	returns other blessed objects, those will be handled in the same
		339	way. "TO_JSON" must take care of not causing an endless recursion
		340	cycle (== crash) in this case. The name of "TO_JSON" was chosen
		341	because other methods called by the Perl core (== not by the user of
		342	the object) are usually in upper case letters and to avoid
		343	collisions with the "to_json" function.
		344
		345	This setting does not yet influence "decode" in any way, but in the
		346	future, global hooks might get installed that influence "decode" and
		347	are enabled by this setting.
		348
		349	If $enable is false, then the "allow_blessed" setting will decide
		350	what to do when a blessed object is found.
		351
		352	$json = $json->filter_json_object ([$coderef->($hashref)])
		353	When $coderef is specified, it will be called from "decode" each
		354	time it decodes a JSON object. The only argument is a reference to
		355	the newly-created hash. If the code references returns a single
		356	scalar (which need not be a reference), this value (i.e. a copy of
		357	that scalar to avoid aliasing) is inserted into the deserialised
		358	data structure. If it returns an empty list (NOTE: not "undef",
		359	which is a valid scalar), the original deserialised hash will be
		360	inserted. This setting can slow down decoding considerably.
		361
		362	When $coderef is omitted or undefined, any existing callback will be
		363	removed and "decode" will not change the deserialised hash in any
		364	way.
		365
		366	Example, convert all JSON objects into the integer 5:
		367
		368	my $js = JSON::XS->new->filter_json_object (sub { 5 });
		369	# returns [5]
		370	$js->decode ('[{}]')
		371	# throw an exception because allow_nonref is not enabled
		372	# so a lone 5 is not allowed.
		373	$js->decode ('{"a":1, "b":2}');
		374
		375	$json = $json->filter_json_single_key_object ($key [=>
		376	$coderef->($value)])
		377	Works remotely similar to "filter_json_object", but is only called
		378	for JSON objects having a single key named $key.
		379
		380	This $coderef is called before the one specified via
		381	"filter_json_object", if any. It gets passed the single value in the
		382	JSON object. If it returns a single value, it will be inserted into
		383	the data structure. If it returns nothing (not even "undef" but the
		384	empty list), the callback from "filter_json_object" will be called
		385	next, as if no single-key callback were specified.
		386
		387	If $coderef is omitted or undefined, the corresponding callback will
		388	be disabled. There can only ever be one callback for a given key.
		389
		390	As this callback gets called less often then the
		391	"filter_json_object" one, decoding speed will not usually suffer as
		392	much. Therefore, single-key objects make excellent targets to
		393	serialise Perl objects into, especially as single-key JSON objects
		394	are as close to the type-tagged value concept as JSON gets (its
		395	basically an ID/VALUE tuple). Of course, JSON does not support this
		396	in any way, so you need to make sure your data never looks like a
		397	serialised Perl hash.
		398
		399	Typical names for the single object key are "__class_whatever__", or
		400	"$__dollars_are_rarely_used__$" or "}ugly_brace_placement", or even
		401	things like "__class_md5sum(classname)__", to reduce the risk of
		402	clashing with real hashes.
		403
		404	Example, decode JSON objects of the form "{ "__widget__" => <id> }"
		405	into the corresponding $WIDGET{<id>} object:
		406
		407	# return whatever is in $WIDGET{5}:
		408	JSON::XS
		409	->new
		410	->filter_json_single_key_object (__widget__ => sub {
		411	$WIDGET{ $_[0] }
		412	})
		413	->decode ('{"__widget__": 5')
		414
		415	# this can be used with a TO_JSON method in some "widget" class
		416	# for serialisation to json:
		417	sub WidgetBase::TO_JSON {
		418	my ($self) = @_;
		419
		420	unless ($self->{id}) {
		421	$self->{id} = ..get..some..id..;
		422	$WIDGET{$self->{id}} = $self;
		423	}
		424
		425	{ __widget__ => $self->{id} }
		426	}
241		427
242	$json = $json->shrink ([$enable])	428	$json = $json->shrink ([$enable])
243	Perl usually over-allocates memory a bit when allocating space for	429	Perl usually over-allocates memory a bit when allocating space for
244	strings. This flag optionally resizes strings generated by either	430	strings. This flag optionally resizes strings generated by either
245	"encode" or "decode" to their minimum size possible. This can save	431	"encode" or "decode" to their minimum size possible. This can save
…		…
265	converting strings that look like integers or floats into integers	451	converting strings that look like integers or floats into integers
266	or floats internally (there is no difference on the Perl level),	452	or floats internally (there is no difference on the Perl level),
267	saving space.	453	saving space.
268		454
269	$json = $json->max_depth ([$maximum_nesting_depth])	455	$json = $json->max_depth ([$maximum_nesting_depth])
270	Sets the maximum nesting level (default 4096) accepted while	456	Sets the maximum nesting level (default 512) accepted while encoding
271	encoding or decoding. If the JSON text or Perl data structure has an	457	or decoding. If the JSON text or Perl data structure has an equal or
272	equal or higher nesting level then this limit, then the encoder and	458	higher nesting level then this limit, then the encoder and decoder
273	decoder will stop and croak at that point.	459	will stop and croak at that point.
274		460
275	Nesting level is defined by number of hash- or arrayrefs that the	461	Nesting level is defined by number of hash- or arrayrefs that the
276	encoder needs to traverse to reach a given point or the number of	462	encoder needs to traverse to reach a given point or the number of
277	"{" or "[" characters without their matching closing parenthesis	463	"{" or "[" characters without their matching closing parenthesis
278	crossed to reach a given character in a string.	464	crossed to reach a given character in a string.
279		465
280	Setting the maximum depth to one disallows any nesting, so that	466	Setting the maximum depth to one disallows any nesting, so that
281	ensures that the object is only a single hash/object or array.	467	ensures that the object is only a single hash/object or array.
282		468
283	The argument to "max_depth" will be rounded up to the next nearest	469	The argument to "max_depth" will be rounded up to the next highest
284	power of two.	470	power of two. If no argument is given, the highest possible setting
		471	will be used, which is rarely useful.
		472
		473	See SECURITY CONSIDERATIONS, below, for more info on why this is
		474	useful.
		475
		476	$json = $json->max_size ([$maximum_string_size])
		477	Set the maximum length a JSON text may have (in bytes) where
		478	decoding is being attempted. The default is 0, meaning no limit.
		479	When "decode" is called on a string longer then this number of
		480	characters it will not attempt to decode the string but throw an
		481	exception. This setting has no effect on "encode" (yet).
		482
		483	The argument to "max_size" will be rounded up to the next highest
		484	power of two (so may be more than requested). If no argument is
		485	given, the limit check will be deactivated (same as when 0 is
		486	specified).
285		487
286	See SECURITY CONSIDERATIONS, below, for more info on why this is	488	See SECURITY CONSIDERATIONS, below, for more info on why this is
287	useful.	489	useful.
288		490
289	$json_text = $json->encode ($perl_scalar)	491	$json_text = $json->encode ($perl_scalar)
…		…
301		503
302	JSON numbers and strings become simple Perl scalars. JSON arrays	504	JSON numbers and strings become simple Perl scalars. JSON arrays
303	become Perl arrayrefs and JSON objects become Perl hashrefs. "true"	505	become Perl arrayrefs and JSON objects become Perl hashrefs. "true"
304	becomes 1, "false" becomes 0 and "null" becomes "undef".	506	becomes 1, "false" becomes 0 and "null" becomes "undef".
305		507
		508	($perl_scalar, $characters) = $json->decode_prefix ($json_text)
		509	This works like the "decode" method, but instead of raising an
		510	exception when there is trailing garbage after the first JSON
		511	object, it will silently stop parsing there and return the number of
		512	characters consumed so far.
		513
		514	This is useful if your JSON texts are not delimited by an outer
		515	protocol (which is not the brightest thing to do in the first place)
		516	and you need to know where the JSON text ends.
		517
		518	JSON::XS->new->decode_prefix ("[1] the tail")
		519	=> ([], 3)
		520
306	MAPPING	521	MAPPING
307	This section describes how JSON::XS maps Perl values to JSON values and	522	This section describes how JSON::XS maps Perl values to JSON values and
308	vice versa. These mappings are designed to "do the right thing" in most	523	vice versa. These mappings are designed to "do the right thing" in most
309	circumstances automatically, preserving round-tripping characteristics	524	circumstances automatically, preserving round-tripping characteristics
310	(what you put in comes out as something equivalent).	525	(what you put in comes out as something equivalent).
…		…
326	A JSON string becomes a string scalar in Perl - Unicode codepoints	541	A JSON string becomes a string scalar in Perl - Unicode codepoints
327	in JSON are represented by the same codepoints in the Perl string,	542	in JSON are represented by the same codepoints in the Perl string,
328	so no manual decoding is necessary.	543	so no manual decoding is necessary.
329		544
330	number	545	number
331	A JSON number becomes either an integer or numeric (floating point)	546	A JSON number becomes either an integer, numeric (floating point) or
332	scalar in perl, depending on its range and any fractional parts. On	547	string scalar in perl, depending on its range and any fractional
333	the Perl level, there is no difference between those as Perl handles	548	parts. On the Perl level, there is no difference between those as
334	all the conversion details, but an integer may take slightly less	549	Perl handles all the conversion details, but an integer may take
335	memory and might represent more values exactly than (floating point)	550	slightly less memory and might represent more values exactly than
336	numbers.	551	(floating point) numbers.
		552
		553	If the number consists of digits only, JSON::XS will try to
		554	represent it as an integer value. If that fails, it will try to
		555	represent it as a numeric (floating point) value if that is possible
		556	without loss of precision. Otherwise it will preserve the number as
		557	a string value.
		558
		559	Numbers containing a fractional or exponential part will always be
		560	represented as numeric (floating point) values, possibly at a loss
		561	of precision.
		562
		563	This might create round-tripping problems as numbers might become
		564	strings, but as Perl is typeless there is no other way to do it.
337		565
338	true, false	566	true, false
339	These JSON atoms become 0, 1, respectively. Information is lost in	567	These JSON atoms become "JSON::XS::true" and "JSON::XS::false",
340	this process. Future versions might represent those values	568	respectively. They are overloaded to act almost exactly like the
341	differently, but they will be guarenteed to act like these integers	569	numbers 1 and 0. You can check wether a scalar is a JSON boolean by
342	would normally in Perl.	570	using the "JSON::XS::is_bool" function.
343		571
344	null	572	null
345	A JSON null atom becomes "undef" in Perl.	573	A JSON null atom becomes "undef" in Perl.
346		574
347	PERL -> JSON	575	PERL -> JSON
…		…
371	can also use "JSON::XS::false" and "JSON::XS::true" to improve	599	can also use "JSON::XS::false" and "JSON::XS::true" to improve
372	readability.	600	readability.
373		601
374	to_json [\0,JSON::XS::true] # yields [false,true]	602	to_json [\0,JSON::XS::true] # yields [false,true]
375		603
		604	JSON::XS::true, JSON::XS::false
		605	These special values become JSON true and JSON false values,
		606	respectively. You cna alos use "\1" and "\0" directly if you want.
		607
376	blessed objects	608	blessed objects
377	Blessed objects are not allowed. JSON::XS currently tries to encode	609	Blessed objects are not allowed. JSON::XS currently tries to encode
378	their underlying representation (hash- or arrayref), but this	610	their underlying representation (hash- or arrayref), but this
379	behaviour might change in future versions.	611	behaviour might change in future versions.
380		612
…		…
410	$x += 0; # numify it, ensuring it will be dumped as a number	642	$x += 0; # numify it, ensuring it will be dumped as a number
411	$x *= 1; # same thing, the choise is yours.	643	$x *= 1; # same thing, the choise is yours.
412		644
413	You can not currently output JSON booleans or force the type in	645	You can not currently output JSON booleans or force the type in
414	other, less obscure, ways. Tell me if you need this capability.	646	other, less obscure, ways. Tell me if you need this capability.
415
416	circular data structures
417	Those will be encoded until memory or stackspace runs out.
418		647
419	COMPARISON	648	COMPARISON
420	As already mentioned, this module was created because none of the	649	As already mentioned, this module was created because none of the
421	existing JSON modules could be made to work correctly. First I will	650	existing JSON modules could be made to work correctly. First I will
422	describe the problems (or pleasures) I encountered with various existing	651	describe the problems (or pleasures) I encountered with various existing
…		…
493	Does not generate valid JSON texts (key strings are often unquoted,	722	Does not generate valid JSON texts (key strings are often unquoted,
494	empty keys result in nothing being output)	723	empty keys result in nothing being output)
495		724
496	Does not check input for validity.	725	Does not check input for validity.
497		726
		727	JSON and YAML
		728	You often hear that JSON is a subset (or a close subset) of YAML. This
		729	is, however, a mass hysteria and very far from the truth. In general,
		730	there is no way to configure JSON::XS to output a data structure as
		731	valid YAML.
		732
		733	If you really must use JSON::XS to generate YAML, you should use this
		734	algorithm (subject to change in future versions):
		735
		736	my $to_yaml = JSON::XS->new->utf8->space_after (1);
		737	my $yaml = $to_yaml->encode ($ref) . "\n";
		738
		739	This will usually generate JSON texts that also parse as valid YAML.
		740	Please note that YAML has hardcoded limits on (simple) object key
		741	lengths that JSON doesn't have, so you should make sure that your hash
		742	keys are noticably shorter than the 1024 characters YAML allows.
		743
		744	There might be other incompatibilities that I am not aware of. In
		745	general you should not try to generate YAML with a JSON generator or
		746	vice versa, or try to parse JSON with a YAML parser or vice versa:
		747	chances are high that you will run into severe interoperability
		748	problems.
		749
498	SPEED	750	SPEED
499	It seems that JSON::XS is surprisingly fast, as shown in the following	751	It seems that JSON::XS is surprisingly fast, as shown in the following
500	tables. They have been generated with the help of the "eg/bench" program	752	tables. They have been generated with the help of the "eg/bench" program
501	in the JSON::XS distribution, to make it easy to compare on your own	753	in the JSON::XS distribution, to make it easy to compare on your own
502	system.	754	system.
503		755
504	First comes a comparison between various modules using a very short JSON	756	First comes a comparison between various modules using a very short
505	string:	757	single-line JSON string:
506		758
507	{"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null}	759	{"method": "handleMessage", "params": ["user1", "we were just talking"], \
		760	"id": null, "array":[1,11,234,-5,1e5,1e7, true, false]}
508		761
509	It shows the number of encodes/decodes per second (JSON::XS uses the	762	It shows the number of encodes/decodes per second (JSON::XS uses the
510	functional interface, while JSON::XS/2 uses the OO interface with	763	functional interface, while JSON::XS/2 uses the OO interface with
511	pretty-printing and hashkey sorting enabled). Higher is better:	764	pretty-printing and hashkey sorting enabled, JSON::XS/3 enables shrink).
		765	Higher is better:
512		766
		767	Storable \| 15779.925 \| 14169.946 \|
		768	-----------+------------+------------+
513	module \| encode \| decode \|	769	module \| encode \| decode \|
514	-----------\|------------\|------------\|	770	-----------\|------------\|------------\|
515	JSON \| 11488.516 \| 7823.035 \|	771	JSON \| 4990.842 \| 4088.813 \|
516	JSON::DWIW \| 94708.054 \| 129094.260 \|	772	JSON::DWIW \| 51653.990 \| 71575.154 \|
517	JSON::PC \| 63884.157 \| 128528.212 \|	773	JSON::PC \| 65948.176 \| 74631.744 \|
		774	JSON::PP \| 8931.652 \| 3817.168 \|
518	JSON::Syck \| 34898.677 \| 42096.911 \|	775	JSON::Syck \| 24877.248 \| 27776.848 \|
519	JSON::XS \| 654027.064 \| 396423.669 \|	776	JSON::XS \| 388361.481 \| 227951.304 \|
520	JSON::XS/2 \| 371564.190 \| 371725.613 \|	777	JSON::XS/2 \| 227951.304 \| 218453.333 \|
		778	JSON::XS/3 \| 338250.323 \| 218453.333 \|
		779	Storable \| 16500.016 \| 135300.129 \|
521	-----------+------------+------------+	780	-----------+------------+------------+
522		781
523	That is, JSON::XS is more than six times faster than JSON::DWIW on	782	That is, JSON::XS is about five times faster than JSON::DWIW on
524	encoding, more than three times faster on decoding, and about thirty	783	encoding, about three times faster on decoding, and over fourty times
525	times faster than JSON, even with pretty-printing and key sorting.	784	faster than JSON, even with pretty-printing and key sorting. It also
		785	compares favourably to Storable for small amounts of data.
526		786
527	Using a longer test string (roughly 18KB, generated from Yahoo! Locals	787	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
528	search API (http://nanoref.com/yahooapis/mgPdGg):	788	search API (http://nanoref.com/yahooapis/mgPdGg):
529		789
530	module \| encode \| decode \|	790	module \| encode \| decode \|
531	-----------\|------------\|------------\|	791	-----------\|------------\|------------\|
532	JSON \| 273.023 \| 44.674 \|	792	JSON \| 55.260 \| 34.971 \|
533	JSON::DWIW \| 1089.383 \| 1145.704 \|	793	JSON::DWIW \| 825.228 \| 1082.513 \|
534	JSON::PC \| 3097.419 \| 2393.921 \|	794	JSON::PC \| 3571.444 \| 2394.829 \|
535	JSON::Syck \| 514.060 \| 843.053 \|	795	JSON::PP \| 210.987 \| 32.574 \|
536	JSON::XS \| 6479.668 \| 3636.364 \|	796	JSON::Syck \| 552.551 \| 787.544 \|
537	JSON::XS/2 \| 3774.221 \| 3599.124 \|	797	JSON::XS \| 5780.463 \| 4854.519 \|
		798	JSON::XS/2 \| 3869.998 \| 4798.975 \|
		799	JSON::XS/3 \| 5862.880 \| 4798.975 \|
		800	Storable \| 4445.002 \| 5235.027 \|
538	-----------+------------+------------+	801	-----------+------------+------------+
539		802
540	Again, JSON::XS leads by far.	803	Again, JSON::XS leads by far (except for Storable which non-surprisingly
		804	decodes faster).
541		805
542	On large strings containing lots of high unicode characters, some	806	On large strings containing lots of high unicode characters, some
543	modules (such as JSON::PC) seem to decode faster than JSON::XS, but the	807	modules (such as JSON::PC) seem to decode faster than JSON::XS, but the
544	result will be broken due to missing (or wrong) unicode handling. Others	808	result will be broken due to missing (or wrong) unicode handling. Others
545	refuse to decode or encode properly, so it was impossible to prepare a	809	refuse to decode or encode properly, so it was impossible to prepare a
…		…
556	Second, you need to avoid resource-starving attacks. That means you	820	Second, you need to avoid resource-starving attacks. That means you
557	should limit the size of JSON texts you accept, or make sure then when	821	should limit the size of JSON texts you accept, or make sure then when
558	your resources run out, thats just fine (e.g. by using a separate	822	your resources run out, thats just fine (e.g. by using a separate
559	process that can crash safely). The size of a JSON text in octets or	823	process that can crash safely). The size of a JSON text in octets or
560	characters is usually a good indication of the size of the resources	824	characters is usually a good indication of the size of the resources
561	required to decode it into a Perl structure.	825	required to decode it into a Perl structure. While JSON::XS can check
		826	the size of the JSON text, it might be too late when you already have it
		827	in memory, so you might want to check the size before you accept the
		828	string.
562		829
563	Third, JSON::XS recurses using the C stack when decoding objects and	830	Third, JSON::XS recurses using the C stack when decoding objects and
564	arrays. The C stack is a limited resource: for instance, on my amd64	831	arrays. The C stack is a limited resource: for instance, on my amd64
565	machine with 8MB of stack size I can decode around 180k nested arrays	832	machine with 8MB of stack size I can decode around 180k nested arrays
566	but only 14k nested JSON objects. If that is exceeded, the program	833	but only 14k nested JSON objects (due to perl itself recursing deeply on
		834	croak to free the temporary). If that is exceeded, the program crashes.
567	crashes. Thats why the default nesting limit is set to 4096. If your	835	to be conservative, the default nesting limit is set to 512. If your
568	process has a smaller stack, you should adjust this setting accordingly	836	process has a smaller stack, you should adjust this setting accordingly
569	with the "max_depth" method.	837	with the "max_depth" method.
570		838
571	And last but least, something else could bomb you that I forgot to think	839	And last but least, something else could bomb you that I forgot to think
572	of. In that case, you get to keep the pieces. I am alway sopen for	840	of. In that case, you get to keep the pieces. I am always open for
573	hints, though...	841	hints, though...
		842
		843	If you are using JSON::XS to return packets to consumption by javascript
		844	scripts in a browser you should have a look at
		845	<http://jpsykes.com/47/practical-csrf-and-json-security> to see wether
		846	you are vulnerable to some common attack vectors (which really are
		847	browser design bugs, but it is still you who will have to deal with it,
		848	as major browser developers care only for features, not about doing
		849	security right).
574		850
575	BUGS	851	BUGS
576	While the goal of this module is to be correct, that unfortunately does	852	While the goal of this module is to be correct, that unfortunately does
577	not mean its bug-free, only that I think its design is bug-free. It is	853	not mean its bug-free, only that I think its design is bug-free. It is
578	still relatively early in its development. If you keep reporting bugs	854	still relatively early in its development. If you keep reporting bugs

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Comparing JSON-XS/README (file contents): Revision 1.9 by root, Thu Mar 29 02:45:49 2007 UTC vs. Revision 1.18 by root, Tue Aug 28 02:06:06 2007 UTC

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Comparing JSON-XS/README (file contents):
Revision 1.9 by root, Thu Mar 29 02:45:49 2007 UTC vs.
Revision 1.18 by root, Tue Aug 28 02:06:06 2007 UTC