[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 1.15 by root, Mon Jul 2 08:06:48 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
…		…
236	Example, encode a Perl scalar as JSON value with enabled	273	Example, encode a Perl scalar as JSON value with enabled
237	"allow_nonref", resulting in an invalid JSON text:	274	"allow_nonref", resulting in an invalid JSON text:
238		275
239	JSON::XS->new->allow_nonref->encode ("Hello, World!")	276	JSON::XS->new->allow_nonref->encode ("Hello, World!")
240	=> "Hello, World!"	277	=> "Hello, World!"
		278
		279	$json = $json->allow_blessed ([$enable])
		280	If $enable is true (or missing), then the "encode" method will not
		281	barf when it encounters a blessed reference. Instead, the value of
		282	the convert_blessed option will decide wether "null"
		283	("convert_blessed" disabled or no "to_json" method found) or a
		284	representation of the object ("convert_blessed" enabled and
		285	"to_json" method found) is being encoded. Has no effect on "decode".
		286
		287	If $enable is false (the default), then "encode" will throw an
		288	exception when it encounters a blessed object.
		289
		290	$json = $json->convert_blessed ([$enable])
		291	If $enable is true (or missing), then "encode", upon encountering a
		292	blessed object, will check for the availability of the "TO_JSON"
		293	method on the object's class. If found, it will be called in scalar
		294	context and the resulting scalar will be encoded instead of the
		295	object. If no "TO_JSON" method is found, the value of
		296	"allow_blessed" will decide what to do.
		297
		298	The "TO_JSON" method may safely call die if it wants. If "TO_JSON"
		299	returns other blessed objects, those will be handled in the same
		300	way. "TO_JSON" must take care of not causing an endless recursion
		301	cycle (== crash) in this case. The name of "TO_JSON" was chosen
		302	because other methods called by the Perl core (== not by the user of
		303	the object) are usually in upper case letters and to avoid
		304	collisions with the "to_json" function.
		305
		306	This setting does not yet influence "decode" in any way, but in the
		307	future, global hooks might get installed that influence "decode" and
		308	are enabled by this setting.
		309
		310	If $enable is false, then the "allow_blessed" setting will decide
		311	what to do when a blessed object is found.
		312
		313	$json = $json->filter_json_object ([$coderef->($hashref)])
		314	When $coderef is specified, it will be called from "decode" each
		315	time it decodes a JSON object. The only argument is a reference to
		316	the newly-created hash. If the code references returns a single
		317	scalar (which need not be a reference), this value (i.e. a copy of
		318	that scalar to avoid aliasing) is inserted into the deserialised
		319	data structure. If it returns an empty list (NOTE: not "undef",
		320	which is a valid scalar), the original deserialised hash will be
		321	inserted. This setting can slow down decoding considerably.
		322
		323	When $coderef is omitted or undefined, any existing callback will be
		324	removed and "decode" will not change the deserialised hash in any
		325	way.
		326
		327	Example, convert all JSON objects into the integer 5:
		328
		329	my $js = JSON::XS->new->filter_json_object (sub { 5 });
		330	# returns [5]
		331	$js->decode ('[{}]')
		332	# throw an exception because allow_nonref is not enabled
		333	# so a lone 5 is not allowed.
		334	$js->decode ('{"a":1, "b":2}');
		335
		336	$json = $json->filter_json_single_key_object ($key [=>
		337	$coderef->($value)])
		338	Works remotely similar to "filter_json_object", but is only called
		339	for JSON objects having a single key named $key.
		340
		341	This $coderef is called before the one specified via
		342	"filter_json_object", if any. It gets passed the single value in the
		343	JSON object. If it returns a single value, it will be inserted into
		344	the data structure. If it returns nothing (not even "undef" but the
		345	empty list), the callback from "filter_json_object" will be called
		346	next, as if no single-key callback were specified.
		347
		348	If $coderef is omitted or undefined, the corresponding callback will
		349	be disabled. There can only ever be one callback for a given key.
		350
		351	As this callback gets called less often then the
		352	"filter_json_object" one, decoding speed will not usually suffer as
		353	much. Therefore, single-key objects make excellent targets to
		354	serialise Perl objects into, especially as single-key JSON objects
		355	are as close to the type-tagged value concept as JSON gets (its
		356	basically an ID/VALUE tuple). Of course, JSON does not support this
		357	in any way, so you need to make sure your data never looks like a
		358	serialised Perl hash.
		359
		360	Typical names for the single object key are "__class_whatever__", or
		361	"$__dollars_are_rarely_used__$" or "}ugly_brace_placement", or even
		362	things like "__class_md5sum(classname)__", to reduce the risk of
		363	clashing with real hashes.
		364
		365	Example, decode JSON objects of the form "{ "__widget__" => <id> }"
		366	into the corresponding $WIDGET{<id>} object:
		367
		368	# return whatever is in $WIDGET{5}:
		369	JSON::XS
		370	->new
		371	->filter_json_single_key_object (__widget__ => sub {
		372	$WIDGET{ $_[0] }
		373	})
		374	->decode ('{"__widget__": 5')
		375
		376	# this can be used with a TO_JSON method in some "widget" class
		377	# for serialisation to json:
		378	sub WidgetBase::TO_JSON {
		379	my ($self) = @_;
		380
		381	unless ($self->{id}) {
		382	$self->{id} = ..get..some..id..;
		383	$WIDGET{$self->{id}} = $self;
		384	}
		385
		386	{ __widget__ => $self->{id} }
		387	}
241		388
242	$json = $json->shrink ([$enable])	389	$json = $json->shrink ([$enable])
243	Perl usually over-allocates memory a bit when allocating space for	390	Perl usually over-allocates memory a bit when allocating space for
244	strings. This flag optionally resizes strings generated by either	391	strings. This flag optionally resizes strings generated by either
245	"encode" or "decode" to their minimum size possible. This can save	392	"encode" or "decode" to their minimum size possible. This can save
…		…
265	converting strings that look like integers or floats into integers	412	converting strings that look like integers or floats into integers
266	or floats internally (there is no difference on the Perl level),	413	or floats internally (there is no difference on the Perl level),
267	saving space.	414	saving space.
268		415
269	$json = $json->max_depth ([$maximum_nesting_depth])	416	$json = $json->max_depth ([$maximum_nesting_depth])
270	Sets the maximum nesting level (default 4096) accepted while	417	Sets the maximum nesting level (default 512) accepted while encoding
271	encoding or decoding. If the JSON text or Perl data structure has an	418	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	419	higher nesting level then this limit, then the encoder and decoder
273	decoder will stop and croak at that point.	420	will stop and croak at that point.
274		421
275	Nesting level is defined by number of hash- or arrayrefs that the	422	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	423	encoder needs to traverse to reach a given point or the number of
277	"{" or "[" characters without their matching closing parenthesis	424	"{" or "[" characters without their matching closing parenthesis
278	crossed to reach a given character in a string.	425	crossed to reach a given character in a string.
279		426
280	Setting the maximum depth to one disallows any nesting, so that	427	Setting the maximum depth to one disallows any nesting, so that
281	ensures that the object is only a single hash/object or array.	428	ensures that the object is only a single hash/object or array.
282		429
283	The argument to "max_depth" will be rounded up to the next nearest	430	The argument to "max_depth" will be rounded up to the next highest
284	power of two.	431	power of two. If no argument is given, the highest possible setting
		432	will be used, which is rarely useful.
		433
		434	See SECURITY CONSIDERATIONS, below, for more info on why this is
		435	useful.
		436
		437	$json = $json->max_size ([$maximum_string_size])
		438	Set the maximum length a JSON text may have (in bytes) where
		439	decoding is being attempted. The default is 0, meaning no limit.
		440	When "decode" is called on a string longer then this number of
		441	characters it will not attempt to decode the string but throw an
		442	exception. This setting has no effect on "encode" (yet).
		443
		444	The argument to "max_size" will be rounded up to the next highest
		445	power of two (so may be more than requested). If no argument is
		446	given, the limit check will be deactivated (same as when 0 is
		447	specified).
285		448
286	See SECURITY CONSIDERATIONS, below, for more info on why this is	449	See SECURITY CONSIDERATIONS, below, for more info on why this is
287	useful.	450	useful.
288		451
289	$json_text = $json->encode ($perl_scalar)	452	$json_text = $json->encode ($perl_scalar)
…		…
301		464
302	JSON numbers and strings become simple Perl scalars. JSON arrays	465	JSON numbers and strings become simple Perl scalars. JSON arrays
303	become Perl arrayrefs and JSON objects become Perl hashrefs. "true"	466	become Perl arrayrefs and JSON objects become Perl hashrefs. "true"
304	becomes 1, "false" becomes 0 and "null" becomes "undef".	467	becomes 1, "false" becomes 0 and "null" becomes "undef".
305		468
		469	($perl_scalar, $characters) = $json->decode_prefix ($json_text)
		470	This works like the "decode" method, but instead of raising an
		471	exception when there is trailing garbage after the first JSON
		472	object, it will silently stop parsing there and return the number of
		473	characters consumed so far.
		474
		475	This is useful if your JSON texts are not delimited by an outer
		476	protocol (which is not the brightest thing to do in the first place)
		477	and you need to know where the JSON text ends.
		478
		479	JSON::XS->new->decode_prefix ("[1] the tail")
		480	=> ([], 3)
		481
306	MAPPING	482	MAPPING
307	This section describes how JSON::XS maps Perl values to JSON values and	483	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	484	vice versa. These mappings are designed to "do the right thing" in most
309	circumstances automatically, preserving round-tripping characteristics	485	circumstances automatically, preserving round-tripping characteristics
310	(what you put in comes out as something equivalent).	486	(what you put in comes out as something equivalent).
…		…
334	all the conversion details, but an integer may take slightly less	510	all the conversion details, but an integer may take slightly less
335	memory and might represent more values exactly than (floating point)	511	memory and might represent more values exactly than (floating point)
336	numbers.	512	numbers.
337		513
338	true, false	514	true, false
339	These JSON atoms become 0, 1, respectively. Information is lost in	515	These JSON atoms become "JSON::XS::true" and "JSON::XS::false",
340	this process. Future versions might represent those values	516	respectively. They are overloaded to act almost exactly like the
341	differently, but they will be guarenteed to act like these integers	517	numbers 1 and 0. You can check wether a scalar is a JSON boolean by
342	would normally in Perl.	518	using the "JSON::XS::is_bool" function.
343		519
344	null	520	null
345	A JSON null atom becomes "undef" in Perl.	521	A JSON null atom becomes "undef" in Perl.
346		522
347	PERL -> JSON	523	PERL -> JSON
…		…
371	can also use "JSON::XS::false" and "JSON::XS::true" to improve	547	can also use "JSON::XS::false" and "JSON::XS::true" to improve
372	readability.	548	readability.
373		549
374	to_json [\0,JSON::XS::true] # yields [false,true]	550	to_json [\0,JSON::XS::true] # yields [false,true]
375		551
		552	JSON::XS::true, JSON::XS::false
		553	These special values become JSON true and JSON false values,
		554	respectively. You cna alos use "\1" and "\0" directly if you want.
		555
376	blessed objects	556	blessed objects
377	Blessed objects are not allowed. JSON::XS currently tries to encode	557	Blessed objects are not allowed. JSON::XS currently tries to encode
378	their underlying representation (hash- or arrayref), but this	558	their underlying representation (hash- or arrayref), but this
379	behaviour might change in future versions.	559	behaviour might change in future versions.
380		560
…		…
410	$x += 0; # numify it, ensuring it will be dumped as a number	590	$x += 0; # numify it, ensuring it will be dumped as a number
411	$x *= 1; # same thing, the choise is yours.	591	$x *= 1; # same thing, the choise is yours.
412		592
413	You can not currently output JSON booleans or force the type in	593	You can not currently output JSON booleans or force the type in
414	other, less obscure, ways. Tell me if you need this capability.	594	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		595
419	COMPARISON	596	COMPARISON
420	As already mentioned, this module was created because none of the	597	As already mentioned, this module was created because none of the
421	existing JSON modules could be made to work correctly. First I will	598	existing JSON modules could be made to work correctly. First I will
422	describe the problems (or pleasures) I encountered with various existing	599	describe the problems (or pleasures) I encountered with various existing
…		…
493	Does not generate valid JSON texts (key strings are often unquoted,	670	Does not generate valid JSON texts (key strings are often unquoted,
494	empty keys result in nothing being output)	671	empty keys result in nothing being output)
495		672
496	Does not check input for validity.	673	Does not check input for validity.
497		674
		675	JSON and YAML
		676	You often hear that JSON is a subset (or a close subset) of YAML. This
		677	is, however, a mass hysteria and very far from the truth. In general,
		678	there is no way to configure JSON::XS to output a data structure as
		679	valid YAML.
		680
		681	If you really must use JSON::XS to generate YAML, you should use this
		682	algorithm (subject to change in future versions):
		683
		684	my $to_yaml = JSON::XS->new->utf8->space_after (1);
		685	my $yaml = $to_yaml->encode ($ref) . "\n";
		686
		687	This will usually generate JSON texts that also parse as valid YAML.
		688	Please note that YAML has hardcoded limits on (simple) object key
		689	lengths that JSON doesn't have, so you should make sure that your hash
		690	keys are noticably shorter than the 1024 characters YAML allows.
		691
		692	There might be other incompatibilities that I am not aware of. In
		693	general you should not try to generate YAML with a JSON generator or
		694	vice versa, or try to parse JSON with a YAML parser or vice versa:
		695	chances are high that you will run into severe interoperability
		696	problems.
		697
498	SPEED	698	SPEED
499	It seems that JSON::XS is surprisingly fast, as shown in the following	699	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	700	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	701	in the JSON::XS distribution, to make it easy to compare on your own
502	system.	702	system.
503		703
504	First comes a comparison between various modules using a very short JSON	704	First comes a comparison between various modules using a very short
505	string:	705	single-line JSON string:
506		706
507	{"method": "handleMessage", "params": ["user1", "we were just talking"], "id": null}	707	{"method": "handleMessage", "params": ["user1", "we were just talking"], \
		708	"id": null, "array":[1,11,234,-5,1e5,1e7, true, false]}
508		709
509	It shows the number of encodes/decodes per second (JSON::XS uses the	710	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	711	functional interface, while JSON::XS/2 uses the OO interface with
511	pretty-printing and hashkey sorting enabled). Higher is better:	712	pretty-printing and hashkey sorting enabled, JSON::XS/3 enables shrink).
		713	Higher is better:
512		714
		715	Storable \| 15779.925 \| 14169.946 \|
		716	-----------+------------+------------+
513	module \| encode \| decode \|	717	module \| encode \| decode \|
514	-----------\|------------\|------------\|	718	-----------\|------------\|------------\|
515	JSON \| 11488.516 \| 7823.035 \|	719	JSON \| 4990.842 \| 4088.813 \|
516	JSON::DWIW \| 94708.054 \| 129094.260 \|	720	JSON::DWIW \| 51653.990 \| 71575.154 \|
517	JSON::PC \| 63884.157 \| 128528.212 \|	721	JSON::PC \| 65948.176 \| 74631.744 \|
		722	JSON::PP \| 8931.652 \| 3817.168 \|
518	JSON::Syck \| 34898.677 \| 42096.911 \|	723	JSON::Syck \| 24877.248 \| 27776.848 \|
519	JSON::XS \| 654027.064 \| 396423.669 \|	724	JSON::XS \| 388361.481 \| 227951.304 \|
520	JSON::XS/2 \| 371564.190 \| 371725.613 \|	725	JSON::XS/2 \| 227951.304 \| 218453.333 \|
		726	JSON::XS/3 \| 338250.323 \| 218453.333 \|
		727	Storable \| 16500.016 \| 135300.129 \|
521	-----------+------------+------------+	728	-----------+------------+------------+
522		729
523	That is, JSON::XS is more than six times faster than JSON::DWIW on	730	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	731	encoding, about three times faster on decoding, and over fourty times
525	times faster than JSON, even with pretty-printing and key sorting.	732	faster than JSON, even with pretty-printing and key sorting. It also
		733	compares favourably to Storable for small amounts of data.
526		734
527	Using a longer test string (roughly 18KB, generated from Yahoo! Locals	735	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
528	search API (http://nanoref.com/yahooapis/mgPdGg):	736	search API (http://nanoref.com/yahooapis/mgPdGg):
529		737
530	module \| encode \| decode \|	738	module \| encode \| decode \|
531	-----------\|------------\|------------\|	739	-----------\|------------\|------------\|
532	JSON \| 273.023 \| 44.674 \|	740	JSON \| 55.260 \| 34.971 \|
533	JSON::DWIW \| 1089.383 \| 1145.704 \|	741	JSON::DWIW \| 825.228 \| 1082.513 \|
534	JSON::PC \| 3097.419 \| 2393.921 \|	742	JSON::PC \| 3571.444 \| 2394.829 \|
535	JSON::Syck \| 514.060 \| 843.053 \|	743	JSON::PP \| 210.987 \| 32.574 \|
536	JSON::XS \| 6479.668 \| 3636.364 \|	744	JSON::Syck \| 552.551 \| 787.544 \|
537	JSON::XS/2 \| 3774.221 \| 3599.124 \|	745	JSON::XS \| 5780.463 \| 4854.519 \|
		746	JSON::XS/2 \| 3869.998 \| 4798.975 \|
		747	JSON::XS/3 \| 5862.880 \| 4798.975 \|
		748	Storable \| 4445.002 \| 5235.027 \|
538	-----------+------------+------------+	749	-----------+------------+------------+
539		750
540	Again, JSON::XS leads by far.	751	Again, JSON::XS leads by far (except for Storable which non-surprisingly
		752	decodes faster).
541		753
542	On large strings containing lots of high unicode characters, some	754	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	755	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	756	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	757	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	768	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	769	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	770	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	771	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	772	characters is usually a good indication of the size of the resources
561	required to decode it into a Perl structure.	773	required to decode it into a Perl structure. While JSON::XS can check
		774	the size of the JSON text, it might be too late when you already have it
		775	in memory, so you might want to check the size before you accept the
		776	string.
562		777
563	Third, JSON::XS recurses using the C stack when decoding objects and	778	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	779	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	780	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	781	but only 14k nested JSON objects (due to perl itself recursing deeply on
		782	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	783	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	784	process has a smaller stack, you should adjust this setting accordingly
569	with the "max_depth" method.	785	with the "max_depth" method.
570		786
571	And last but least, something else could bomb you that I forgot to think	787	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	788	of. In that case, you get to keep the pieces. I am always open for
573	hints, though...	789	hints, though...
		790
		791	If you are using JSON::XS to return packets to consumption by javascript
		792	scripts in a browser you should have a look at
		793	<http://jpsykes.com/47/practical-csrf-and-json-security> to see wether
		794	you are vulnerable to some common attack vectors (which really are
		795	browser design bugs, but it is still you who will have to deal with it,
		796	as major browser developers care only for features, not about doing
		797	security right).
574		798
575	BUGS	799	BUGS
576	While the goal of this module is to be correct, that unfortunately does	800	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	801	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	802	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 1.15 by root, Mon Jul 2 08:06:48 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 1.15 by root, Mon Jul 2 08:06:48 2007 UTC