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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.43 by root, Sat Jun 23 23:49:29 2007 UTC vs.
Revision 1.56 by root, Thu Jul 26 11:33:35 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 = '1.3';	86	our $VERSION = '1.43';
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
…		…
315	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,	311	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,
316	resulting in an invalid JSON text:	312	resulting in an invalid JSON text:
317		313
318	JSON::XS->new->allow_nonref->encode ("Hello, World!")	314	JSON::XS->new->allow_nonref->encode ("Hello, World!")
319	=> "Hello, World!"	315	=> "Hello, World!"
		316
		317	=item $json = $json->allow_blessed ([$enable])
		318
		319	If C<$enable> is true (or missing), then the C<encode> method will not
		320	barf when it encounters a blessed reference. Instead, the value of the
		321	B<convert_blessed> option will decide wether C<null> (C<convert_blessed>
		322	disabled or no C<to_json> method found) or a representation of the
		323	object (C<convert_blessed> enabled and C<to_json> method found) is being
		324	encoded. Has no effect on C<decode>.
		325
		326	If C<$enable> is false (the default), then C<encode> will throw an
		327	exception when it encounters a blessed object.
		328
		329	=item $json = $json->convert_blessed ([$enable])
		330
		331	If C<$enable> is true (or missing), then C<encode>, upon encountering a
		332	blessed object, will check for the availability of the C<TO_JSON> method
		333	on the object's class. If found, it will be called in scalar context
		334	and the resulting scalar will be encoded instead of the object. If no
		335	C<TO_JSON> method is found, the value of C<allow_blessed> will decide what
		336	to do.
		337
		338	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
		339	returns other blessed objects, those will be handled in the same
		340	way. C<TO_JSON> must take care of not causing an endless recursion cycle
		341	(== crash) in this case. The name of C<TO_JSON> was chosen because other
		342	methods called by the Perl core (== not by the user of the object) are
		343	usually in upper case letters and to avoid collisions with the C<to_json>
		344	function.
		345
		346	This setting does not yet influence C<decode> in any way, but in the
		347	future, global hooks might get installed that influence C<decode> and are
		348	enabled by this setting.
		349
		350	If C<$enable> is false, then the C<allow_blessed> setting will decide what
		351	to do when a blessed object is found.
		352
		353	=item $json = $json->filter_json_object ([$coderef->($hashref)])
		354
		355	When C<$coderef> is specified, it will be called from C<decode> each
		356	time it decodes a JSON object. The only argument is a reference to the
		357	newly-created hash. If the code references returns a single scalar (which
		358	need not be a reference), this value (i.e. a copy of that scalar to avoid
		359	aliasing) is inserted into the deserialised data structure. If it returns
		360	an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the
		361	original deserialised hash will be inserted. This setting can slow down
		362	decoding considerably.
		363
		364	When C<$coderef> is omitted or undefined, any existing callback will
		365	be removed and C<decode> will not change the deserialised hash in any
		366	way.
		367
		368	Example, convert all JSON objects into the integer 5:
		369
		370	my $js = JSON::XS->new->filter_json_object (sub { 5 });
		371	# returns [5]
		372	$js->decode ('[{}]')
		373	# throw an exception because allow_nonref is not enabled
		374	# so a lone 5 is not allowed.
		375	$js->decode ('{"a":1, "b":2}');
		376
		377	=item $json = $json->filter_json_single_key_object ($key [=> $coderef->($value)])
		378
		379	Works remotely similar to C<filter_json_object>, but is only called for
		380	JSON objects having a single key named C<$key>.
		381
		382	This C<$coderef> is called before the one specified via
		383	C<filter_json_object>, if any. It gets passed the single value in the JSON
		384	object. If it returns a single value, it will be inserted into the data
		385	structure. If it returns nothing (not even C<undef> but the empty list),
		386	the callback from C<filter_json_object> will be called next, as if no
		387	single-key callback were specified.
		388
		389	If C<$coderef> is omitted or undefined, the corresponding callback will be
		390	disabled. There can only ever be one callback for a given key.
		391
		392	As this callback gets called less often then the C<filter_json_object>
		393	one, decoding speed will not usually suffer as much. Therefore, single-key
		394	objects make excellent targets to serialise Perl objects into, especially
		395	as single-key JSON objects are as close to the type-tagged value concept
		396	as JSON gets (its basically an ID/VALUE tuple). Of course, JSON does not
		397	support this in any way, so you need to make sure your data never looks
		398	like a serialised Perl hash.
		399
		400	Typical names for the single object key are C<__class_whatever__>, or
		401	C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even
		402	things like C<__class_md5sum(classname)__>, to reduce the risk of clashing
		403	with real hashes.
		404
		405	Example, decode JSON objects of the form C<< { "__widget__" => <id> } >>
		406	into the corresponding C<< $WIDGET{<id>} >> object:
		407
		408	# return whatever is in $WIDGET{5}:
		409	JSON::XS
		410	->new
		411	->filter_json_single_key_object (__widget__ => sub {
		412	$WIDGET{ $_[0] }
		413	})
		414	->decode ('{"__widget__": 5')
		415
		416	# this can be used with a TO_JSON method in some "widget" class
		417	# for serialisation to json:
		418	sub WidgetBase::TO_JSON {
		419	my ($self) = @_;
		420
		421	unless ($self->{id}) {
		422	$self->{id} = ..get..some..id..;
		423	$WIDGET{$self->{id}} = $self;
		424	}
		425
		426	{ __widget__ => $self->{id} }
		427	}
320		428
321	=item $json = $json->shrink ([$enable])	429	=item $json = $json->shrink ([$enable])
322		430
323	Perl usually over-allocates memory a bit when allocating space for	431	Perl usually over-allocates memory a bit when allocating space for
324	strings. This flag optionally resizes strings generated by either	432	strings. This flag optionally resizes strings generated by either
…		…
357	given character in a string.	465	given character in a string.
358		466
359	Setting the maximum depth to one disallows any nesting, so that ensures	467	Setting the maximum depth to one disallows any nesting, so that ensures
360	that the object is only a single hash/object or array.	468	that the object is only a single hash/object or array.
361		469
362	The argument to C<max_depth> will be rounded up to the next nearest power	470	The argument to C<max_depth> will be rounded up to the next highest power
363	of two.	471	of two. If no argument is given, the highest possible setting will be
		472	used, which is rarely useful.
		473
		474	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
		475
		476	=item $json = $json->max_size ([$maximum_string_size])
		477
		478	Set the maximum length a JSON text may have (in bytes) where decoding is
		479	being attempted. The default is C<0>, meaning no limit. When C<decode>
		480	is called on a string longer then this number of characters it will not
		481	attempt to decode the string but throw an exception. This setting has no
		482	effect on C<encode> (yet).
		483
		484	The argument to C<max_size> will be rounded up to the next B<highest>
		485	power of two (so may be more than requested). If no argument is given, the
		486	limit check will be deactivated (same as when C<0> is specified).
364		487
365	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	488	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
366		489
367	=item $json_text = $json->encode ($perl_scalar)	490	=item $json_text = $json->encode ($perl_scalar)
368		491
…		…
430	are represented by the same codepoints in the Perl string, so no manual	553	are represented by the same codepoints in the Perl string, so no manual
431	decoding is necessary.	554	decoding is necessary.
432		555
433	=item number	556	=item number
434		557
435	A JSON number becomes either an integer or numeric (floating point)	558	A JSON number becomes either an integer, numeric (floating point) or
436	scalar in perl, depending on its range and any fractional parts. On the	559	string scalar in perl, depending on its range and any fractional parts. On
437	Perl level, there is no difference between those as Perl handles all the	560	the Perl level, there is no difference between those as Perl handles all
438	conversion details, but an integer may take slightly less memory and might	561	the conversion details, but an integer may take slightly less memory and
439	represent more values exactly than (floating point) numbers.	562	might represent more values exactly than (floating point) numbers.
		563
		564	If the number consists of digits only, JSON::XS will try to represent
		565	it as an integer value. If that fails, it will try to represent it as
		566	a numeric (floating point) value if that is possible without loss of
		567	precision. Otherwise it will preserve the number as a string value.
		568
		569	Numbers containing a fractional or exponential part will always be
		570	represented as numeric (floating point) values, possibly at a loss of
		571	precision.
		572
		573	This might create round-tripping problems as numbers might become strings,
		574	but as Perl is typeless there is no other way to do it.
440		575
441	=item true, false	576	=item true, false
442		577
443	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,	578	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,
444	respectively. They are overloaded to act almost exactly like the numbers	579	respectively. They are overloaded to act almost exactly like the numbers
…		…
660	It shows the number of encodes/decodes per second (JSON::XS uses	795	It shows the number of encodes/decodes per second (JSON::XS uses
661	the functional interface, while JSON::XS/2 uses the OO interface	796	the functional interface, while JSON::XS/2 uses the OO interface
662	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables	797	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables
663	shrink). Higher is better:	798	shrink). Higher is better:
664		799
		800	Storable \| 15779.925 \| 14169.946 \|
		801	-----------+------------+------------+
665	module \| encode \| decode \|	802	module \| encode \| decode \|
666	-----------\|------------\|------------\|	803	-----------\|------------\|------------\|
667	JSON \| 7645.468 \| 4208.613 \|	804	JSON \| 4990.842 \| 4088.813 \|
668	JSON::DWIW \| 40721.398 \| 77101.176 \|	805	JSON::DWIW \| 51653.990 \| 71575.154 \|
669	JSON::PC \| 65948.176 \| 78251.940 \|	806	JSON::PC \| 65948.176 \| 74631.744 \|
670	JSON::Syck \| 22844.793 \| 26479.192 \|	807	JSON::PP \| 8931.652 \| 3817.168 \|
		808	JSON::Syck \| 24877.248 \| 27776.848 \|
671	JSON::XS \| 388361.481 \| 199728.762 \|	809	JSON::XS \| 388361.481 \| 227951.304 \|
672	JSON::XS/2 \| 218453.333 \| 192399.266 \|	810	JSON::XS/2 \| 227951.304 \| 218453.333 \|
673	JSON::XS/3 \| 338250.323 \| 192399.266 \|	811	JSON::XS/3 \| 338250.323 \| 218453.333 \|
674	Storable \| 15779.925 \| 14169.946 \|	812	Storable \| 16500.016 \| 135300.129 \|
675	-----------+------------+------------+	813	-----------+------------+------------+
676		814
677	That is, JSON::XS is about five times faster than JSON::DWIW on encoding,	815	That is, JSON::XS is about five times faster than JSON::DWIW on encoding,
678	about three times faster on decoding, and over fourty times faster	816	about three times faster on decoding, and over fourty times faster
679	than JSON, even with pretty-printing and key sorting. It also compares	817	than JSON, even with pretty-printing and key sorting. It also compares
…		…
682	Using a longer test string (roughly 18KB, generated from Yahoo! Locals	820	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
683	search API (http://nanoref.com/yahooapis/mgPdGg):	821	search API (http://nanoref.com/yahooapis/mgPdGg):
684		822
685	module \| encode \| decode \|	823	module \| encode \| decode \|
686	-----------\|------------\|------------\|	824	-----------\|------------\|------------\|
687	JSON \| 254.685 \| 37.665 \|	825	JSON \| 55.260 \| 34.971 \|
688	JSON::DWIW \| 843.343 \| 1049.731 \|	826	JSON::DWIW \| 825.228 \| 1082.513 \|
689	JSON::PC \| 3602.116 \| 2307.352 \|	827	JSON::PC \| 3571.444 \| 2394.829 \|
		828	JSON::PP \| 210.987 \| 32.574 \|
690	JSON::Syck \| 505.107 \| 787.899 \|	829	JSON::Syck \| 552.551 \| 787.544 \|
691	JSON::XS \| 5747.196 \| 3690.220 \|	830	JSON::XS \| 5780.463 \| 4854.519 \|
692	JSON::XS/2 \| 3968.121 \| 3676.634 \|	831	JSON::XS/2 \| 3869.998 \| 4798.975 \|
693	JSON::XS/3 \| 6105.246 \| 3662.508 \|	832	JSON::XS/3 \| 5862.880 \| 4798.975 \|
694	Storable \| 4417.337 \| 5285.161 \|	833	Storable \| 4445.002 \| 5235.027 \|
695	-----------+------------+------------+	834	-----------+------------+------------+
696		835
697	Again, JSON::XS leads by far (except for Storable which non-surprisingly	836	Again, JSON::XS leads by far (except for Storable which non-surprisingly
698	decodes faster).	837	decodes faster).
699		838
…		…
716	Second, you need to avoid resource-starving attacks. That means you should	855	Second, you need to avoid resource-starving attacks. That means you should
717	limit the size of JSON texts you accept, or make sure then when your	856	limit the size of JSON texts you accept, or make sure then when your
718	resources run out, thats just fine (e.g. by using a separate process that	857	resources run out, thats just fine (e.g. by using a separate process that
719	can crash safely). The size of a JSON text in octets or characters is	858	can crash safely). The size of a JSON text in octets or characters is
720	usually a good indication of the size of the resources required to decode	859	usually a good indication of the size of the resources required to decode
721	it into a Perl structure.	860	it into a Perl structure. While JSON::XS can check the size of the JSON
		861	text, it might be too late when you already have it in memory, so you
		862	might want to check the size before you accept the string.
722		863
723	Third, JSON::XS recurses using the C stack when decoding objects and	864	Third, JSON::XS recurses using the C stack when decoding objects and
724	arrays. The C stack is a limited resource: for instance, on my amd64	865	arrays. The C stack is a limited resource: for instance, on my amd64
725	machine with 8MB of stack size I can decode around 180k nested arrays but	866	machine with 8MB of stack size I can decode around 180k nested arrays but
726	only 14k nested JSON objects (due to perl itself recursing deeply on croak	867	only 14k nested JSON objects (due to perl itself recursing deeply on croak
…		…
757	sub true() { $true }	898	sub true() { $true }
758	sub false() { $false }	899	sub false() { $false }
759		900
760	sub is_bool($) {	901	sub is_bool($) {
761	UNIVERSAL::isa $_[0], "JSON::XS::Boolean"	902	UNIVERSAL::isa $_[0], "JSON::XS::Boolean"
762	or UNIVERSAL::isa $_[0], "JSON::Literal"	903	# or UNIVERSAL::isa $_[0], "JSON::Literal"
763	}	904	}
764		905
765	XSLoader::load "JSON::XS", $VERSION;	906	XSLoader::load "JSON::XS", $VERSION;
766		907
767	package JSON::XS::Boolean;	908	package JSON::XS::Boolean;

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Comparing JSON-XS/XS.pm (file contents): Revision 1.43 by root, Sat Jun 23 23:49:29 2007 UTC vs. Revision 1.56 by root, Thu Jul 26 11:33:35 2007 UTC

Diff Legend

Comparing JSON-XS/XS.pm (file contents):
Revision 1.43 by root, Sat Jun 23 23:49:29 2007 UTC vs.
Revision 1.56 by root, Thu Jul 26 11:33:35 2007 UTC