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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.42 by root, Thu Jun 14 23:58:57 2007 UTC vs.
Revision 1.61 by root, Wed Sep 12 17:42:36 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	BEGIN {
91	our $VERSION = '1.24';	86	our $VERSION = '1.5';
92	our @ISA = qw(Exporter);	87	our @ISA = qw(Exporter);
93		88
94	our @EXPORT = qw(to_json from_json objToJson jsonToObj);	89	our @EXPORT = qw(to_json from_json);
95	require Exporter;
96		90
97	require XSLoader;	91	use Exporter;
98	XSLoader::load JSON::XS::, $VERSION;	92	use XSLoader;
99	}
100		93
101	=head1 FUNCTIONAL INTERFACE	94	=head1 FUNCTIONAL INTERFACE
102		95
103	The following convinience methods are provided by this module. They are	96	The following convinience methods are provided by this module. They are
104	exported by default:	97	exported by default:
…		…
126	This function call is functionally identical to:	119	This function call is functionally identical to:
127		120
128	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)	121	$perl_scalar = JSON::XS->new->utf8->decode ($json_text)
129		122
130	except being faster.	123	except being faster.
		124
		125	=item $is_boolean = JSON::XS::is_bool $scalar
		126
		127	Returns true if the passed scalar represents either JSON::XS::true or
		128	JSON::XS::false, two constants that act like C<1> and C<0>, respectively
		129	and are used to represent JSON C<true> and C<false> values in Perl.
		130
		131	See MAPPING, below, for more information on how JSON values are mapped to
		132	Perl.
131		133
132	=back	134	=back
133		135
134		136
135	=head1 OBJECT-ORIENTED INTERFACE	137	=head1 OBJECT-ORIENTED INTERFACE
…		…
276		278
277	Example, space_before and indent disabled, space_after enabled:	279	Example, space_before and indent disabled, space_after enabled:
278		280
279	{"key": "value"}	281	{"key": "value"}
280		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	=item * shell-style '#'-comments
		316
		317	Whenever JSON allows whitespace, shell-style comments are additionally
		318	allowed. They are terminated by the first carriage-return or line-feed
		319	character, after which more white-space and comments are allowed.
		320
		321	[
		322	1, # this comment not allowed in JSON
		323	# neither this one...
		324	]
		325
		326	=back
		327
281	=item $json = $json->canonical ([$enable])	328	=item $json = $json->canonical ([$enable])
282		329
283	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects	330	If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
284	by sorting their keys. This is adding a comparatively high overhead.	331	by sorting their keys. This is adding a comparatively high overhead.
285		332
…		…
309	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,	356	Example, encode a Perl scalar as JSON value with enabled C<allow_nonref>,
310	resulting in an invalid JSON text:	357	resulting in an invalid JSON text:
311		358
312	JSON::XS->new->allow_nonref->encode ("Hello, World!")	359	JSON::XS->new->allow_nonref->encode ("Hello, World!")
313	=> "Hello, World!"	360	=> "Hello, World!"
		361
		362	=item $json = $json->allow_blessed ([$enable])
		363
		364	If C<$enable> is true (or missing), then the C<encode> method will not
		365	barf when it encounters a blessed reference. Instead, the value of the
		366	B<convert_blessed> option will decide wether C<null> (C<convert_blessed>
		367	disabled or no C<to_json> method found) or a representation of the
		368	object (C<convert_blessed> enabled and C<to_json> method found) is being
		369	encoded. Has no effect on C<decode>.
		370
		371	If C<$enable> is false (the default), then C<encode> will throw an
		372	exception when it encounters a blessed object.
		373
		374	=item $json = $json->convert_blessed ([$enable])
		375
		376	If C<$enable> is true (or missing), then C<encode>, upon encountering a
		377	blessed object, will check for the availability of the C<TO_JSON> method
		378	on the object's class. If found, it will be called in scalar context
		379	and the resulting scalar will be encoded instead of the object. If no
		380	C<TO_JSON> method is found, the value of C<allow_blessed> will decide what
		381	to do.
		382
		383	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
		384	returns other blessed objects, those will be handled in the same
		385	way. C<TO_JSON> must take care of not causing an endless recursion cycle
		386	(== crash) in this case. The name of C<TO_JSON> was chosen because other
		387	methods called by the Perl core (== not by the user of the object) are
		388	usually in upper case letters and to avoid collisions with the C<to_json>
		389	function.
		390
		391	This setting does not yet influence C<decode> in any way, but in the
		392	future, global hooks might get installed that influence C<decode> and are
		393	enabled by this setting.
		394
		395	If C<$enable> is false, then the C<allow_blessed> setting will decide what
		396	to do when a blessed object is found.
		397
		398	=item $json = $json->filter_json_object ([$coderef->($hashref)])
		399
		400	When C<$coderef> is specified, it will be called from C<decode> each
		401	time it decodes a JSON object. The only argument is a reference to the
		402	newly-created hash. If the code references returns a single scalar (which
		403	need not be a reference), this value (i.e. a copy of that scalar to avoid
		404	aliasing) is inserted into the deserialised data structure. If it returns
		405	an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the
		406	original deserialised hash will be inserted. This setting can slow down
		407	decoding considerably.
		408
		409	When C<$coderef> is omitted or undefined, any existing callback will
		410	be removed and C<decode> will not change the deserialised hash in any
		411	way.
		412
		413	Example, convert all JSON objects into the integer 5:
		414
		415	my $js = JSON::XS->new->filter_json_object (sub { 5 });
		416	# returns [5]
		417	$js->decode ('[{}]')
		418	# throw an exception because allow_nonref is not enabled
		419	# so a lone 5 is not allowed.
		420	$js->decode ('{"a":1, "b":2}');
		421
		422	=item $json = $json->filter_json_single_key_object ($key [=> $coderef->($value)])
		423
		424	Works remotely similar to C<filter_json_object>, but is only called for
		425	JSON objects having a single key named C<$key>.
		426
		427	This C<$coderef> is called before the one specified via
		428	C<filter_json_object>, if any. It gets passed the single value in the JSON
		429	object. If it returns a single value, it will be inserted into the data
		430	structure. If it returns nothing (not even C<undef> but the empty list),
		431	the callback from C<filter_json_object> will be called next, as if no
		432	single-key callback were specified.
		433
		434	If C<$coderef> is omitted or undefined, the corresponding callback will be
		435	disabled. There can only ever be one callback for a given key.
		436
		437	As this callback gets called less often then the C<filter_json_object>
		438	one, decoding speed will not usually suffer as much. Therefore, single-key
		439	objects make excellent targets to serialise Perl objects into, especially
		440	as single-key JSON objects are as close to the type-tagged value concept
		441	as JSON gets (its basically an ID/VALUE tuple). Of course, JSON does not
		442	support this in any way, so you need to make sure your data never looks
		443	like a serialised Perl hash.
		444
		445	Typical names for the single object key are C<__class_whatever__>, or
		446	C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even
		447	things like C<__class_md5sum(classname)__>, to reduce the risk of clashing
		448	with real hashes.
		449
		450	Example, decode JSON objects of the form C<< { "__widget__" => <id> } >>
		451	into the corresponding C<< $WIDGET{<id>} >> object:
		452
		453	# return whatever is in $WIDGET{5}:
		454	JSON::XS
		455	->new
		456	->filter_json_single_key_object (__widget__ => sub {
		457	$WIDGET{ $_[0] }
		458	})
		459	->decode ('{"__widget__": 5')
		460
		461	# this can be used with a TO_JSON method in some "widget" class
		462	# for serialisation to json:
		463	sub WidgetBase::TO_JSON {
		464	my ($self) = @_;
		465
		466	unless ($self->{id}) {
		467	$self->{id} = ..get..some..id..;
		468	$WIDGET{$self->{id}} = $self;
		469	}
		470
		471	{ __widget__ => $self->{id} }
		472	}
314		473
315	=item $json = $json->shrink ([$enable])	474	=item $json = $json->shrink ([$enable])
316		475
317	Perl usually over-allocates memory a bit when allocating space for	476	Perl usually over-allocates memory a bit when allocating space for
318	strings. This flag optionally resizes strings generated by either	477	strings. This flag optionally resizes strings generated by either
…		…
351	given character in a string.	510	given character in a string.
352		511
353	Setting the maximum depth to one disallows any nesting, so that ensures	512	Setting the maximum depth to one disallows any nesting, so that ensures
354	that the object is only a single hash/object or array.	513	that the object is only a single hash/object or array.
355		514
356	The argument to C<max_depth> will be rounded up to the next nearest power	515	The argument to C<max_depth> will be rounded up to the next highest power
357	of two.	516	of two. If no argument is given, the highest possible setting will be
		517	used, which is rarely useful.
		518
		519	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
		520
		521	=item $json = $json->max_size ([$maximum_string_size])
		522
		523	Set the maximum length a JSON text may have (in bytes) where decoding is
		524	being attempted. The default is C<0>, meaning no limit. When C<decode>
		525	is called on a string longer then this number of characters it will not
		526	attempt to decode the string but throw an exception. This setting has no
		527	effect on C<encode> (yet).
		528
		529	The argument to C<max_size> will be rounded up to the next B<highest>
		530	power of two (so may be more than requested). If no argument is given, the
		531	limit check will be deactivated (same as when C<0> is specified).
358		532
359	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.	533	See SECURITY CONSIDERATIONS, below, for more info on why this is useful.
360		534
361	=item $json_text = $json->encode ($perl_scalar)	535	=item $json_text = $json->encode ($perl_scalar)
362		536
…		…
424	are represented by the same codepoints in the Perl string, so no manual	598	are represented by the same codepoints in the Perl string, so no manual
425	decoding is necessary.	599	decoding is necessary.
426		600
427	=item number	601	=item number
428		602
429	A JSON number becomes either an integer or numeric (floating point)	603	A JSON number becomes either an integer, numeric (floating point) or
430	scalar in perl, depending on its range and any fractional parts. On the	604	string scalar in perl, depending on its range and any fractional parts. On
431	Perl level, there is no difference between those as Perl handles all the	605	the Perl level, there is no difference between those as Perl handles all
432	conversion details, but an integer may take slightly less memory and might	606	the conversion details, but an integer may take slightly less memory and
433	represent more values exactly than (floating point) numbers.	607	might represent more values exactly than (floating point) numbers.
		608
		609	If the number consists of digits only, JSON::XS will try to represent
		610	it as an integer value. If that fails, it will try to represent it as
		611	a numeric (floating point) value if that is possible without loss of
		612	precision. Otherwise it will preserve the number as a string value.
		613
		614	Numbers containing a fractional or exponential part will always be
		615	represented as numeric (floating point) values, possibly at a loss of
		616	precision.
		617
		618	This might create round-tripping problems as numbers might become strings,
		619	but as Perl is typeless there is no other way to do it.
434		620
435	=item true, false	621	=item true, false
436		622
437	These JSON atoms become C<0>, C<1>, respectively. Information is lost in	623	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,
438	this process. Future versions might represent those values differently,	624	respectively. They are overloaded to act almost exactly like the numbers
439	but they will be guarenteed to act like these integers would normally in	625	C<1> and C<0>. You can check wether a scalar is a JSON boolean by using
440	Perl.	626	the C<JSON::XS::is_bool> function.
441		627
442	=item null	628	=item null
443		629
444	A JSON null atom becomes C<undef> in Perl.	630	A JSON null atom becomes C<undef> in Perl.
445		631
…		…
477	C<1>, which get turned into C<false> and C<true> atoms in JSON. You can	663	C<1>, which get turned into C<false> and C<true> atoms in JSON. You can
478	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.	664	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.
479		665
480	to_json [\0,JSON::XS::true] # yields [false,true]	666	to_json [\0,JSON::XS::true] # yields [false,true]
481		667
		668	=item JSON::XS::true, JSON::XS::false
		669
		670	These special values become JSON true and JSON false values,
		671	respectively. You can also use C<\1> and C<\0> directly if you want.
		672
482	=item blessed objects	673	=item blessed objects
483		674
484	Blessed objects are not allowed. JSON::XS currently tries to encode their	675	Blessed objects are not allowed. JSON::XS currently tries to encode their
485	underlying representation (hash- or arrayref), but this behaviour might	676	underlying representation (hash- or arrayref), but this behaviour might
486	change in future versions.	677	change in future versions.
…		…
649	It shows the number of encodes/decodes per second (JSON::XS uses	840	It shows the number of encodes/decodes per second (JSON::XS uses
650	the functional interface, while JSON::XS/2 uses the OO interface	841	the functional interface, while JSON::XS/2 uses the OO interface
651	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables	842	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables
652	shrink). Higher is better:	843	shrink). Higher is better:
653		844
		845	Storable \| 15779.925 \| 14169.946 \|
		846	-----------+------------+------------+
654	module \| encode \| decode \|	847	module \| encode \| decode \|
655	-----------\|------------\|------------\|	848	-----------\|------------\|------------\|
656	JSON \| 7645.468 \| 4208.613 \|	849	JSON \| 4990.842 \| 4088.813 \|
657	JSON::DWIW \| 40721.398 \| 77101.176 \|	850	JSON::DWIW \| 51653.990 \| 71575.154 \|
658	JSON::PC \| 65948.176 \| 78251.940 \|	851	JSON::PC \| 65948.176 \| 74631.744 \|
659	JSON::Syck \| 22844.793 \| 26479.192 \|	852	JSON::PP \| 8931.652 \| 3817.168 \|
		853	JSON::Syck \| 24877.248 \| 27776.848 \|
660	JSON::XS \| 388361.481 \| 199728.762 \|	854	JSON::XS \| 388361.481 \| 227951.304 \|
661	JSON::XS/2 \| 218453.333 \| 192399.266 \|	855	JSON::XS/2 \| 227951.304 \| 218453.333 \|
662	JSON::XS/3 \| 338250.323 \| 192399.266 \|	856	JSON::XS/3 \| 338250.323 \| 218453.333 \|
663	Storable \| 15779.925 \| 14169.946 \|	857	Storable \| 16500.016 \| 135300.129 \|
664	-----------+------------+------------+	858	-----------+------------+------------+
665		859
666	That is, JSON::XS is about five times faster than JSON::DWIW on encoding,	860	That is, JSON::XS is about five times faster than JSON::DWIW on encoding,
667	about three times faster on decoding, and over fourty times faster	861	about three times faster on decoding, and over fourty times faster
668	than JSON, even with pretty-printing and key sorting. It also compares	862	than JSON, even with pretty-printing and key sorting. It also compares
…		…
671	Using a longer test string (roughly 18KB, generated from Yahoo! Locals	865	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
672	search API (http://nanoref.com/yahooapis/mgPdGg):	866	search API (http://nanoref.com/yahooapis/mgPdGg):
673		867
674	module \| encode \| decode \|	868	module \| encode \| decode \|
675	-----------\|------------\|------------\|	869	-----------\|------------\|------------\|
676	JSON \| 254.685 \| 37.665 \|	870	JSON \| 55.260 \| 34.971 \|
677	JSON::DWIW \| 843.343 \| 1049.731 \|	871	JSON::DWIW \| 825.228 \| 1082.513 \|
678	JSON::PC \| 3602.116 \| 2307.352 \|	872	JSON::PC \| 3571.444 \| 2394.829 \|
		873	JSON::PP \| 210.987 \| 32.574 \|
679	JSON::Syck \| 505.107 \| 787.899 \|	874	JSON::Syck \| 552.551 \| 787.544 \|
680	JSON::XS \| 5747.196 \| 3690.220 \|	875	JSON::XS \| 5780.463 \| 4854.519 \|
681	JSON::XS/2 \| 3968.121 \| 3676.634 \|	876	JSON::XS/2 \| 3869.998 \| 4798.975 \|
682	JSON::XS/3 \| 6105.246 \| 3662.508 \|	877	JSON::XS/3 \| 5862.880 \| 4798.975 \|
683	Storable \| 4417.337 \| 5285.161 \|	878	Storable \| 4445.002 \| 5235.027 \|
684	-----------+------------+------------+	879	-----------+------------+------------+
685		880
686	Again, JSON::XS leads by far (except for Storable which non-surprisingly	881	Again, JSON::XS leads by far (except for Storable which non-surprisingly
687	decodes faster).	882	decodes faster).
688		883
…		…
705	Second, you need to avoid resource-starving attacks. That means you should	900	Second, you need to avoid resource-starving attacks. That means you should
706	limit the size of JSON texts you accept, or make sure then when your	901	limit the size of JSON texts you accept, or make sure then when your
707	resources run out, thats just fine (e.g. by using a separate process that	902	resources run out, thats just fine (e.g. by using a separate process that
708	can crash safely). The size of a JSON text in octets or characters is	903	can crash safely). The size of a JSON text in octets or characters is
709	usually a good indication of the size of the resources required to decode	904	usually a good indication of the size of the resources required to decode
710	it into a Perl structure.	905	it into a Perl structure. While JSON::XS can check the size of the JSON
		906	text, it might be too late when you already have it in memory, so you
		907	might want to check the size before you accept the string.
711		908
712	Third, JSON::XS recurses using the C stack when decoding objects and	909	Third, JSON::XS recurses using the C stack when decoding objects and
713	arrays. The C stack is a limited resource: for instance, on my amd64	910	arrays. The C stack is a limited resource: for instance, on my amd64
714	machine with 8MB of stack size I can decode around 180k nested arrays but	911	machine with 8MB of stack size I can decode around 180k nested arrays but
715	only 14k nested JSON objects (due to perl itself recursing deeply on croak	912	only 14k nested JSON objects (due to perl itself recursing deeply on croak
…		…
738	still relatively early in its development. If you keep reporting bugs they	935	still relatively early in its development. If you keep reporting bugs they
739	will be fixed swiftly, though.	936	will be fixed swiftly, though.
740		937
741	=cut	938	=cut
742		939
		940	our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" };
		941	our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" };
		942
743	sub true() { \1 }	943	sub true() { $true }
744	sub false() { \0 }	944	sub false() { $false }
		945
		946	sub is_bool($) {
		947	UNIVERSAL::isa $_[0], "JSON::XS::Boolean"
		948	# or UNIVERSAL::isa $_[0], "JSON::Literal"
		949	}
		950
		951	XSLoader::load "JSON::XS", $VERSION;
		952
		953	package JSON::XS::Boolean;
		954
		955	use overload
		956	"0+" => sub { ${$_[0]} },
		957	"++" => sub { $_[0] = ${$_[0]} + 1 },
		958	"--" => sub { $_[0] = ${$_[0]} - 1 },
		959	fallback => 1;
745		960
746	1;	961	1;
747		962
748	=head1 AUTHOR	963	=head1 AUTHOR
749		964

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Comparing JSON-XS/XS.pm (file contents): Revision 1.42 by root, Thu Jun 14 23:58:57 2007 UTC vs. Revision 1.61 by root, Wed Sep 12 17:42:36 2007 UTC

Diff Legend

Comparing JSON-XS/XS.pm (file contents):
Revision 1.42 by root, Thu Jun 14 23:58:57 2007 UTC vs.
Revision 1.61 by root, Wed Sep 12 17:42:36 2007 UTC