[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 1.60 by root, Mon Aug 27 02:03:23 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	=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
287	=item $json = $json->canonical ([$enable])	328	=item $json = $json->canonical ([$enable])
288		329
289	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
290	by sorting their keys. This is adding a comparatively high overhead.	331	by sorting their keys. This is adding a comparatively high overhead.
291		332
…		…
341		382
342	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>	383	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	384	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	385	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	386	(== 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	387	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>	388	usually in upper case letters and to avoid collisions with the C<to_json>
348	function.	389	function.
349		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
350	If C<$enable> is false, then the C<allow_blessed> setting will decide what	395	If C<$enable> is false, then the C<allow_blessed> setting will decide what
351	to do when a blessed object is found.	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	}
352		473
353	=item $json = $json->shrink ([$enable])	474	=item $json = $json->shrink ([$enable])
354		475
355	Perl usually over-allocates memory a bit when allocating space for	476	Perl usually over-allocates memory a bit when allocating space for
356	strings. This flag optionally resizes strings generated by either	477	strings. This flag optionally resizes strings generated by either
…		…
389	given character in a string.	510	given character in a string.
390		511
391	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
392	that the object is only a single hash/object or array.	513	that the object is only a single hash/object or array.
393		514
394	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
395	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).
396		532
397	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.
398		534
399	=item $json_text = $json->encode ($perl_scalar)	535	=item $json_text = $json->encode ($perl_scalar)
400		536
…		…
462	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
463	decoding is necessary.	599	decoding is necessary.
464		600
465	=item number	601	=item number
466		602
467	A JSON number becomes either an integer or numeric (floating point)	603	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	604	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	605	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	606	the conversion details, but an integer may take slightly less memory and
471	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.
472		620
473	=item true, false	621	=item true, false
474		622
475	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,	623	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	624	respectively. They are overloaded to act almost exactly like the numbers
…		…
692	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
693	the functional interface, while JSON::XS/2 uses the OO interface	841	the functional interface, while JSON::XS/2 uses the OO interface
694	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables	842	with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables
695	shrink). Higher is better:	843	shrink). Higher is better:
696		844
		845	Storable \| 15779.925 \| 14169.946 \|
		846	-----------+------------+------------+
697	module \| encode \| decode \|	847	module \| encode \| decode \|
698	-----------\|------------\|------------\|	848	-----------\|------------\|------------\|
699	JSON \| 7645.468 \| 4208.613 \|	849	JSON \| 4990.842 \| 4088.813 \|
700	JSON::DWIW \| 40721.398 \| 77101.176 \|	850	JSON::DWIW \| 51653.990 \| 71575.154 \|
701	JSON::PC \| 65948.176 \| 78251.940 \|	851	JSON::PC \| 65948.176 \| 74631.744 \|
702	JSON::Syck \| 22844.793 \| 26479.192 \|	852	JSON::PP \| 8931.652 \| 3817.168 \|
		853	JSON::Syck \| 24877.248 \| 27776.848 \|
703	JSON::XS \| 388361.481 \| 199728.762 \|	854	JSON::XS \| 388361.481 \| 227951.304 \|
704	JSON::XS/2 \| 218453.333 \| 192399.266 \|	855	JSON::XS/2 \| 227951.304 \| 218453.333 \|
705	JSON::XS/3 \| 338250.323 \| 192399.266 \|	856	JSON::XS/3 \| 338250.323 \| 218453.333 \|
706	Storable \| 15779.925 \| 14169.946 \|	857	Storable \| 16500.016 \| 135300.129 \|
707	-----------+------------+------------+	858	-----------+------------+------------+
708		859
709	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,
710	about three times faster on decoding, and over fourty times faster	861	about three times faster on decoding, and over fourty times faster
711	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
…		…
714	Using a longer test string (roughly 18KB, generated from Yahoo! Locals	865	Using a longer test string (roughly 18KB, generated from Yahoo! Locals
715	search API (http://nanoref.com/yahooapis/mgPdGg):	866	search API (http://nanoref.com/yahooapis/mgPdGg):
716		867
717	module \| encode \| decode \|	868	module \| encode \| decode \|
718	-----------\|------------\|------------\|	869	-----------\|------------\|------------\|
719	JSON \| 254.685 \| 37.665 \|	870	JSON \| 55.260 \| 34.971 \|
720	JSON::DWIW \| 843.343 \| 1049.731 \|	871	JSON::DWIW \| 825.228 \| 1082.513 \|
721	JSON::PC \| 3602.116 \| 2307.352 \|	872	JSON::PC \| 3571.444 \| 2394.829 \|
		873	JSON::PP \| 210.987 \| 32.574 \|
722	JSON::Syck \| 505.107 \| 787.899 \|	874	JSON::Syck \| 552.551 \| 787.544 \|
723	JSON::XS \| 5747.196 \| 3690.220 \|	875	JSON::XS \| 5780.463 \| 4854.519 \|
724	JSON::XS/2 \| 3968.121 \| 3676.634 \|	876	JSON::XS/2 \| 3869.998 \| 4798.975 \|
725	JSON::XS/3 \| 6105.246 \| 3662.508 \|	877	JSON::XS/3 \| 5862.880 \| 4798.975 \|
726	Storable \| 4417.337 \| 5285.161 \|	878	Storable \| 4445.002 \| 5235.027 \|
727	-----------+------------+------------+	879	-----------+------------+------------+
728		880
729	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
730	decodes faster).	882	decodes faster).
731		883
…		…
748	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
749	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
750	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
751	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
752	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
753	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.
754		908
755	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
756	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
757	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
758	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

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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 1.60 by root, Mon Aug 27 02:03:23 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 1.60 by root, Mon Aug 27 02:03:23 2007 UTC