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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.44 by root, Mon Jun 25 04:08:17 2007 UTC vs.
Revision 1.59 by root, Mon Aug 27 01:49:01 2007 UTC

…		…
9	# exported functions, they croak on error	9	# exported functions, they croak on error
10	# and expect/generate UTF-8	10	# and expect/generate UTF-8
11		11
12	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;	12	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;
13	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;	13	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;
14
15	# objToJson and jsonToObj aliases to to_json and from_json
16	# are exported for compatibility to the JSON module,
17	# but should not be used in new code.
18		14
19	# OO-interface	15	# OO-interface
20		16
21	$coder = JSON::XS->new->ascii->pretty->allow_nonref;	17	$coder = JSON::XS->new->ascii->pretty->allow_nonref;
22	$pretty_printed_unencoded = $coder->encode ($perl_scalar);	18	$pretty_printed_unencoded = $coder->encode ($perl_scalar);
…		…
85		81
86	package JSON::XS;	82	package JSON::XS;
87		83
88	use strict;	84	use strict;
89		85
90	our $VERSION = '1.4';	86	our $VERSION = '1.5';
91	our @ISA = qw(Exporter);	87	our @ISA = qw(Exporter);
92		88
93	our @EXPORT = qw(to_json from_json objToJson jsonToObj);	89	our @EXPORT = qw(to_json from_json);
94		90
95	use Exporter;	91	use Exporter;
96	use XSLoader;	92	use XSLoader;
97		93
98	=head1 FUNCTIONAL INTERFACE	94	=head1 FUNCTIONAL INTERFACE
…		…
282		278
283	Example, space_before and indent disabled, space_after enabled:	279	Example, space_before and indent disabled, space_after enabled:
284		280
285	{"key": "value"}	281	{"key": "value"}
286		282
		283	=item $json = $json->relaxed ([$enable])
		284
		285	If C<$enable> is true (or missing), then C<decode> will accept some
		286	extensions to normal JSON syntax (see below). C<encode> will not be
		287	affected in anyway. I<Be aware that this option makes you accept invalid
		288	JSON texts as if they were valid!>. I suggest only to use this option to
		289	parse application-specific files written by humans (configuration files,
		290	resource files etc.)
		291
		292	If C<$enable> is false (the default), then C<decode> will only accept
		293	valid JSON texts.
		294
		295	Currently accepted extensions are:
		296
		297	=over 4
		298
		299	=item * list items can have an end-comma
		300
		301	JSON I<separates> array elements and key-value pairs with commas. This
		302	can be annoying if you write JSON texts manually and want to be able to
		303	quickly append elements, so this extension accepts comma at the end of
		304	such items not just between them:
		305
		306	[
		307	1,
		308	2, <- this comma not normally allowed
		309	]
		310	{
		311	"k1": "v1",
		312	"k2": "v2", <- this comma not normally allowed
		313	}
		314
		315	=back
		316
287	=item $json = $json->canonical ([$enable])	317	=item $json = $json->canonical ([$enable])
288		318
289	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects	319	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
290	by sorting their keys. This is adding a comparatively high overhead.	320	by sorting their keys. This is adding a comparatively high overhead.
291		321
…		…
341		371
342	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>	372	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
343	returns other blessed objects, those will be handled in the same	373	returns other blessed objects, those will be handled in the same
344	way. C<TO_JSON> must take care of not causing an endless recursion cycle	374	way. C<TO_JSON> must take care of not causing an endless recursion cycle
345	(== crash) in this case. The name of C<TO_JSON> was chosen because other	375	(== crash) in this case. The name of C<TO_JSON> was chosen because other
346	methods called by the Perl core (== not the user of the object) are	376	methods called by the Perl core (== not by the user of the object) are
347	usually in upper case letters and to avoid collisions with the C<to_json>	377	usually in upper case letters and to avoid collisions with the C<to_json>
348	function.	378	function.
349		379
		380	This setting does not yet influence C<decode> in any way, but in the
		381	future, global hooks might get installed that influence C<decode> and are
		382	enabled by this setting.
		383
350	If C<$enable> is false, then the C<allow_blessed> setting will decide what	384	If C<$enable> is false, then the C<allow_blessed> setting will decide what
351	to do when a blessed object is found.	385	to do when a blessed object is found.
		386
		387	=item $json = $json->filter_json_object ([$coderef->($hashref)])
		388
		389	When C<$coderef> is specified, it will be called from C<decode> each
		390	time it decodes a JSON object. The only argument is a reference to the
		391	newly-created hash. If the code references returns a single scalar (which
		392	need not be a reference), this value (i.e. a copy of that scalar to avoid
		393	aliasing) is inserted into the deserialised data structure. If it returns
		394	an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the
		395	original deserialised hash will be inserted. This setting can slow down
		396	decoding considerably.
		397
		398	When C<$coderef> is omitted or undefined, any existing callback will
		399	be removed and C<decode> will not change the deserialised hash in any
		400	way.
		401
		402	Example, convert all JSON objects into the integer 5:
		403
		404	my $js = JSON::XS->new->filter_json_object (sub { 5 });
		405	# returns [5]
		406	$js->decode ('[{}]')
		407	# throw an exception because allow_nonref is not enabled
		408	# so a lone 5 is not allowed.
		409	$js->decode ('{"a":1, "b":2}');
		410
		411	=item $json = $json->filter_json_single_key_object ($key [=> $coderef->($value)])
		412
		413	Works remotely similar to C<filter_json_object>, but is only called for
		414	JSON objects having a single key named C<$key>.
		415
		416	This C<$coderef> is called before the one specified via
		417	C<filter_json_object>, if any. It gets passed the single value in the JSON
		418	object. If it returns a single value, it will be inserted into the data
		419	structure. If it returns nothing (not even C<undef> but the empty list),
		420	the callback from C<filter_json_object> will be called next, as if no
		421	single-key callback were specified.
		422
		423	If C<$coderef> is omitted or undefined, the corresponding callback will be
		424	disabled. There can only ever be one callback for a given key.
		425
		426	As this callback gets called less often then the C<filter_json_object>
		427	one, decoding speed will not usually suffer as much. Therefore, single-key
		428	objects make excellent targets to serialise Perl objects into, especially
		429	as single-key JSON objects are as close to the type-tagged value concept
		430	as JSON gets (its basically an ID/VALUE tuple). Of course, JSON does not
		431	support this in any way, so you need to make sure your data never looks
		432	like a serialised Perl hash.
		433
		434	Typical names for the single object key are C<__class_whatever__>, or
		435	C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even
		436	things like C<__class_md5sum(classname)__>, to reduce the risk of clashing
		437	with real hashes.
		438
		439	Example, decode JSON objects of the form C<< { "__widget__" => <id> } >>
		440	into the corresponding C<< $WIDGET{<id>} >> object:
		441
		442	# return whatever is in $WIDGET{5}:
		443	JSON::XS
		444	->new
		445	->filter_json_single_key_object (__widget__ => sub {
		446	$WIDGET{ $_[0] }
		447	})
		448	->decode ('{"__widget__": 5')
		449
		450	# this can be used with a TO_JSON method in some "widget" class
		451	# for serialisation to json:
		452	sub WidgetBase::TO_JSON {
		453	my ($self) = @_;
		454
		455	unless ($self->{id}) {
		456	$self->{id} = ..get..some..id..;
		457	$WIDGET{$self->{id}} = $self;
		458	}
		459
		460	{ __widget__ => $self->{id} }
		461	}
352		462
353	=item $json = $json->shrink ([$enable])	463	=item $json = $json->shrink ([$enable])
354		464
355	Perl usually over-allocates memory a bit when allocating space for	465	Perl usually over-allocates memory a bit when allocating space for
356	strings. This flag optionally resizes strings generated by either	466	strings. This flag optionally resizes strings generated by either
…		…
389	given character in a string.	499	given character in a string.
390		500
391	Setting the maximum depth to one disallows any nesting, so that ensures	501	Setting the maximum depth to one disallows any nesting, so that ensures
392	that the object is only a single hash/object or array.	502	that the object is only a single hash/object or array.
393		503
394	The argument to C<max_depth> will be rounded up to the next nearest power	504	The argument to C<max_depth> will be rounded up to the next highest power
395	of two.	505	of two. If no argument is given, the highest possible setting will be
		506	used, which is rarely useful.
		507
		508	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
		509
		510	=item $json = $json->max_size ([$maximum_string_size])
		511
		512	Set the maximum length a JSON text may have (in bytes) where decoding is
		513	being attempted. The default is C<0>, meaning no limit. When C<decode>
		514	is called on a string longer then this number of characters it will not
		515	attempt to decode the string but throw an exception. This setting has no
		516	effect on C<encode> (yet).
		517
		518	The argument to C<max_size> will be rounded up to the next B<highest>
		519	power of two (so may be more than requested). If no argument is given, the
		520	limit check will be deactivated (same as when C<0> is specified).
396		521
397	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	522	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
398		523
399	=item $json_text = $json->encode ($perl_scalar)	524	=item $json_text = $json->encode ($perl_scalar)
400		525
…		…
462	are represented by the same codepoints in the Perl string, so no manual	587	are represented by the same codepoints in the Perl string, so no manual
463	decoding is necessary.	588	decoding is necessary.
464		589
465	=item number	590	=item number
466		591
467	A JSON number becomes either an integer or numeric (floating point)	592	A JSON number becomes either an integer, numeric (floating point) or
468	scalar in perl, depending on its range and any fractional parts. On the	593	string scalar in perl, depending on its range and any fractional parts. On
469	Perl level, there is no difference between those as Perl handles all the	594	the Perl level, there is no difference between those as Perl handles all
470	conversion details, but an integer may take slightly less memory and might	595	the conversion details, but an integer may take slightly less memory and
471	represent more values exactly than (floating point) numbers.	596	might represent more values exactly than (floating point) numbers.
		597
		598	If the number consists of digits only, JSON::XS will try to represent
		599	it as an integer value. If that fails, it will try to represent it as
		600	a numeric (floating point) value if that is possible without loss of
		601	precision. Otherwise it will preserve the number as a string value.
		602
		603	Numbers containing a fractional or exponential part will always be
		604	represented as numeric (floating point) values, possibly at a loss of
		605	precision.
		606
		607	This might create round-tripping problems as numbers might become strings,
		608	but as Perl is typeless there is no other way to do it.
472		609
473	=item true, false	610	=item true, false
474		611
475	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,	612	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,
476	respectively. They are overloaded to act almost exactly like the numbers	613	respectively. They are overloaded to act almost exactly like the numbers
…		…
692	It shows the number of encodes/decodes per second (JSON::XS uses	829	It shows the number of encodes/decodes per second (JSON::XS uses
693	the functional interface, while JSON::XS/2 uses the OO interface	830	the functional interface, while JSON::XS/2 uses the OO interface
694	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables	831	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables
695	shrink). Higher is better:	832	shrink). Higher is better:
696		833
		834	Storable \| 15779.925 \| 14169.946 \|
		835	-----------+------------+------------+
697	module \| encode \| decode \|	836	module \| encode \| decode \|
698	-----------\|------------\|------------\|	837	-----------\|------------\|------------\|
699	JSON \| 7645.468 \| 4208.613 \|	838	JSON \| 4990.842 \| 4088.813 \|
700	JSON::DWIW \| 40721.398 \| 77101.176 \|	839	JSON::DWIW \| 51653.990 \| 71575.154 \|
701	JSON::PC \| 65948.176 \| 78251.940 \|	840	JSON::PC \| 65948.176 \| 74631.744 \|
702	JSON::Syck \| 22844.793 \| 26479.192 \|	841	JSON::PP \| 8931.652 \| 3817.168 \|
		842	JSON::Syck \| 24877.248 \| 27776.848 \|
703	JSON::XS \| 388361.481 \| 199728.762 \|	843	JSON::XS \| 388361.481 \| 227951.304 \|
704	JSON::XS/2 \| 218453.333 \| 192399.266 \|	844	JSON::XS/2 \| 227951.304 \| 218453.333 \|
705	JSON::XS/3 \| 338250.323 \| 192399.266 \|	845	JSON::XS/3 \| 338250.323 \| 218453.333 \|
706	Storable \| 15779.925 \| 14169.946 \|	846	Storable \| 16500.016 \| 135300.129 \|
707	-----------+------------+------------+	847	-----------+------------+------------+
708		848
709	That is, JSON::XS is about five times faster than JSON::DWIW on encoding,	849	That is, JSON::XS is about five times faster than JSON::DWIW on encoding,
710	about three times faster on decoding, and over fourty times faster	850	about three times faster on decoding, and over fourty times faster
711	than JSON, even with pretty-printing and key sorting. It also compares	851	than JSON, even with pretty-printing and key sorting. It also compares
…		…
714	Using a longer test string (roughly 18KB, generated from Yahoo! Locals	854	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
715	search API (http://nanoref.com/yahooapis/mgPdGg):	855	search API (http://nanoref.com/yahooapis/mgPdGg):
716		856
717	module \| encode \| decode \|	857	module \| encode \| decode \|
718	-----------\|------------\|------------\|	858	-----------\|------------\|------------\|
719	JSON \| 254.685 \| 37.665 \|	859	JSON \| 55.260 \| 34.971 \|
720	JSON::DWIW \| 843.343 \| 1049.731 \|	860	JSON::DWIW \| 825.228 \| 1082.513 \|
721	JSON::PC \| 3602.116 \| 2307.352 \|	861	JSON::PC \| 3571.444 \| 2394.829 \|
		862	JSON::PP \| 210.987 \| 32.574 \|
722	JSON::Syck \| 505.107 \| 787.899 \|	863	JSON::Syck \| 552.551 \| 787.544 \|
723	JSON::XS \| 5747.196 \| 3690.220 \|	864	JSON::XS \| 5780.463 \| 4854.519 \|
724	JSON::XS/2 \| 3968.121 \| 3676.634 \|	865	JSON::XS/2 \| 3869.998 \| 4798.975 \|
725	JSON::XS/3 \| 6105.246 \| 3662.508 \|	866	JSON::XS/3 \| 5862.880 \| 4798.975 \|
726	Storable \| 4417.337 \| 5285.161 \|	867	Storable \| 4445.002 \| 5235.027 \|
727	-----------+------------+------------+	868	-----------+------------+------------+
728		869
729	Again, JSON::XS leads by far (except for Storable which non-surprisingly	870	Again, JSON::XS leads by far (except for Storable which non-surprisingly
730	decodes faster).	871	decodes faster).
731		872
…		…
748	Second, you need to avoid resource-starving attacks. That means you should	889	Second, you need to avoid resource-starving attacks. That means you should
749	limit the size of JSON texts you accept, or make sure then when your	890	limit the size of JSON texts you accept, or make sure then when your
750	resources run out, thats just fine (e.g. by using a separate process that	891	resources run out, thats just fine (e.g. by using a separate process that
751	can crash safely). The size of a JSON text in octets or characters is	892	can crash safely). The size of a JSON text in octets or characters is
752	usually a good indication of the size of the resources required to decode	893	usually a good indication of the size of the resources required to decode
753	it into a Perl structure.	894	it into a Perl structure. While JSON::XS can check the size of the JSON
		895	text, it might be too late when you already have it in memory, so you
		896	might want to check the size before you accept the string.
754		897
755	Third, JSON::XS recurses using the C stack when decoding objects and	898	Third, JSON::XS recurses using the C stack when decoding objects and
756	arrays. The C stack is a limited resource: for instance, on my amd64	899	arrays. The C stack is a limited resource: for instance, on my amd64
757	machine with 8MB of stack size I can decode around 180k nested arrays but	900	machine with 8MB of stack size I can decode around 180k nested arrays but
758	only 14k nested JSON objects (due to perl itself recursing deeply on croak	901	only 14k nested JSON objects (due to perl itself recursing deeply on croak

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Comparing JSON-XS/XS.pm (file contents): Revision 1.44 by root, Mon Jun 25 04:08:17 2007 UTC vs. Revision 1.59 by root, Mon Aug 27 01:49:01 2007 UTC

Diff Legend

Comparing JSON-XS/XS.pm (file contents):
Revision 1.44 by root, Mon Jun 25 04:08:17 2007 UTC vs.
Revision 1.59 by root, Mon Aug 27 01:49:01 2007 UTC