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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.77 by root, Tue Dec 4 10:37:42 2007 UTC vs.
Revision 1.86 by root, Wed Mar 19 03:17:38 2008 UTC

…		…
		1	=encoding utf-8
		2
1	=head1 NAME	3	=head1 NAME
2		4
3	JSON::XS - JSON serialising/deserialising, done correctly and fast	5	JSON::XS - JSON serialising/deserialising, done correctly and fast
4		6
5	JSON::XS - 正しくて高速な JSON シリアライザ/デシリアライザ	7	JSON::XS - 正しくて高速な JSON シリアライザ/デシリアライザ
10	use JSON::XS;	12	use JSON::XS;
11		13
12	# exported functions, they croak on error	14	# exported functions, they croak on error
13	# and expect/generate UTF-8	15	# and expect/generate UTF-8
14		16
15	$utf8_encoded_json_text = to_json $perl_hash_or_arrayref;	17	$utf8_encoded_json_text = encode_json $perl_hash_or_arrayref;
16	$perl_hash_or_arrayref = from_json $utf8_encoded_json_text;	18	$perl_hash_or_arrayref = decode_json $utf8_encoded_json_text;
17		19
18	# OO-interface	20	# OO-interface
19		21
20	$coder = JSON::XS->new->ascii->pretty->allow_nonref;	22	$coder = JSON::XS->new->ascii->pretty->allow_nonref;
21	$pretty_printed_unencoded = $coder->encode ($perl_scalar);	23	$pretty_printed_unencoded = $coder->encode ($perl_scalar);
…		…
58		60
59	=over 4	61	=over 4
60		62
61	=item * correct Unicode handling	63	=item * correct Unicode handling
62		64
63	This module knows how to handle Unicode, and even documents how and when	65	This module knows how to handle Unicode, documents how and when it does
64	it does so.	66	so, and even documents what "correct" means.
65		67
66	=item * round-trip integrity	68	=item * round-trip integrity
67		69
68	When you serialise a perl data structure using only datatypes supported	70	When you serialise a perl data structure using only datatypes supported
69	by JSON, the deserialised data structure is identical on the Perl level.	71	by JSON, the deserialised data structure is identical on the Perl level.
70	(e.g. the string "2.0" doesn't suddenly become "2" just because it looks	72	(e.g. the string "2.0" doesn't suddenly become "2" just because it looks
71	like a number).	73	like a number). There minor I<are> exceptions to this, read the MAPPING
		74	section below to learn about those.
72		75
73	=item * strict checking of JSON correctness	76	=item * strict checking of JSON correctness
74		77
75	There is no guessing, no generating of illegal JSON texts by default,	78	There is no guessing, no generating of illegal JSON texts by default,
76	and only JSON is accepted as input by default (the latter is a security	79	and only JSON is accepted as input by default (the latter is a security
77	feature).	80	feature).
78		81
79	=item * fast	82	=item * fast
80		83
81	Compared to other JSON modules, this module compares favourably in terms	84	Compared to other JSON modules and other serialisers such as Storable,
82	of speed, too.	85	this module usually compares favourably in terms of speed, too.
83		86
84	=item * simple to use	87	=item * simple to use
85		88
86	This module has both a simple functional interface as well as an OO	89	This module has both a simple functional interface as well as an objetc
87	interface.	90	oriented interface interface.
88		91
89	=item * reasonably versatile output formats	92	=item * reasonably versatile output formats
90		93
91	You can choose between the most compact guaranteed single-line format	94	You can choose between the most compact guaranteed-single-line format
92	possible (nice for simple line-based protocols), a pure-ascii format	95	possible (nice for simple line-based protocols), a pure-ascii format
93	(for when your transport is not 8-bit clean, still supports the whole	96	(for when your transport is not 8-bit clean, still supports the whole
94	Unicode range), or a pretty-printed format (for when you want to read that	97	Unicode range), or a pretty-printed format (for when you want to read that
95	stuff). Or you can combine those features in whatever way you like.	98	stuff). Or you can combine those features in whatever way you like.
96		99
…		…
100		103
101	package JSON::XS;	104	package JSON::XS;
102		105
103	use strict;	106	use strict;
104		107
105	our $VERSION = '2.0';	108	our $VERSION = '2.01';
106	our @ISA = qw(Exporter);	109	our @ISA = qw(Exporter);
107		110
108	our @EXPORT = qw(to_json from_json);	111	our @EXPORT = qw(encode_json decode_json to_json from_json);
		112
		113	sub to_json($) {
		114	require Carp;
		115	Carp::croak ("JSON::XS::to_json has been renamed to encode_json, either downgrade to pre-2.0 versions of JSON::XS or rename the call");
		116	}
		117
		118	sub from_json($) {
		119	require Carp;
		120	Carp::croak ("JSON::XS::from_json has been renamed to decode_json, either downgrade to pre-2.0 versions of JSON::XS or rename the call");
		121	}
109		122
110	use Exporter;	123	use Exporter;
111	use XSLoader;	124	use XSLoader;
112		125
113	=head1 FUNCTIONAL INTERFACE	126	=head1 FUNCTIONAL INTERFACE
…		…
115	The following convenience methods are provided by this module. They are	128	The following convenience methods are provided by this module. They are
116	exported by default:	129	exported by default:
117		130
118	=over 4	131	=over 4
119		132
120	=item $json_text = to_json $perl_scalar	133	=item $json_text = encode_json $perl_scalar
121		134
122	Converts the given Perl data structure to a UTF-8 encoded, binary string	135	Converts the given Perl data structure to a UTF-8 encoded, binary string
123	(that is, the string contains octets only). Croaks on error.	136	(that is, the string contains octets only). Croaks on error.
124		137
125	This function call is functionally identical to:	138	This function call is functionally identical to:
126		139
127	$json_text = JSON::XS->new->utf8->encode ($perl_scalar)	140	$json_text = JSON::XS->new->utf8->encode ($perl_scalar)
128		141
129	except being faster.	142	except being faster.
130		143
131	=item $perl_scalar = from_json $json_text	144	=item $perl_scalar = decode_json $json_text
132		145
133	The opposite of C<to_json>: expects an UTF-8 (binary) string and tries	146	The opposite of C<encode_json>: expects an UTF-8 (binary) string and tries
134	to parse that as an UTF-8 encoded JSON text, returning the resulting	147	to parse that as an UTF-8 encoded JSON text, returning the resulting
135	reference. Croaks on error.	148	reference. Croaks on error.
136		149
137	This function call is functionally identical to:	150	This function call is functionally identical to:
138		151
…		…
164	This enables you to store Unicode characters as single characters in a	177	This enables you to store Unicode characters as single characters in a
165	Perl string - very natural.	178	Perl string - very natural.
166		179
167	=item 2. Perl does I<not> associate an encoding with your strings.	180	=item 2. Perl does I<not> associate an encoding with your strings.
168		181
169	Unless you force it to, e.g. when matching it against a regex, or printing	182	... until you force it to, e.g. when matching it against a regex, or
170	the scalar to a file, in which case Perl either interprets your string as	183	printing the scalar to a file, in which case Perl either interprets your
171	locale-encoded text, octets/binary, or as Unicode, depending on various	184	string as locale-encoded text, octets/binary, or as Unicode, depending
172	settings. In no case is an encoding stored together with your data, it is	185	on various settings. In no case is an encoding stored together with your
173	I<use> that decides encoding, not any magical metadata.	186	data, it is I<use> that decides encoding, not any magical meta data.
174		187
175	=item 3. The internal utf-8 flag has no meaning with regards to the	188	=item 3. The internal utf-8 flag has no meaning with regards to the
176	encoding of your string.	189	encoding of your string.
177		190
178	Just ignore that flag unless you debug a Perl bug, a module written in	191	Just ignore that flag unless you debug a Perl bug, a module written in
…		…
471	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>	484	The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON>
472	returns other blessed objects, those will be handled in the same	485	returns other blessed objects, those will be handled in the same
473	way. C<TO_JSON> must take care of not causing an endless recursion cycle	486	way. C<TO_JSON> must take care of not causing an endless recursion cycle
474	(== crash) in this case. The name of C<TO_JSON> was chosen because other	487	(== crash) in this case. The name of C<TO_JSON> was chosen because other
475	methods called by the Perl core (== not by the user of the object) are	488	methods called by the Perl core (== not by the user of the object) are
476	usually in upper case letters and to avoid collisions with the C<to_json>	489	usually in upper case letters and to avoid collisions with any C<to_json>
477	function.	490	function or method.
478		491
479	This setting does not yet influence C<decode> in any way, but in the	492	This setting does not yet influence C<decode> in any way, but in the
480	future, global hooks might get installed that influence C<decode> and are	493	future, global hooks might get installed that influence C<decode> and are
481	enabled by this setting.	494	enabled by this setting.
482		495
…		…
696		709
697	A JSON number becomes either an integer, numeric (floating point) or	710	A JSON number becomes either an integer, numeric (floating point) or
698	string scalar in perl, depending on its range and any fractional parts. On	711	string scalar in perl, depending on its range and any fractional parts. On
699	the Perl level, there is no difference between those as Perl handles all	712	the Perl level, there is no difference between those as Perl handles all
700	the conversion details, but an integer may take slightly less memory and	713	the conversion details, but an integer may take slightly less memory and
701	might represent more values exactly than (floating point) numbers.	714	might represent more values exactly than floating point numbers.
702		715
703	If the number consists of digits only, JSON::XS will try to represent	716	If the number consists of digits only, JSON::XS will try to represent
704	it as an integer value. If that fails, it will try to represent it as	717	it as an integer value. If that fails, it will try to represent it as
705	a numeric (floating point) value if that is possible without loss of	718	a numeric (floating point) value if that is possible without loss of
706	precision. Otherwise it will preserve the number as a string value.	719	precision. Otherwise it will preserve the number as a string value (in
		720	which case you lose roundtripping ability, as the JSON number will be
		721	re-encoded toa JSON string).
707		722
708	Numbers containing a fractional or exponential part will always be	723	Numbers containing a fractional or exponential part will always be
709	represented as numeric (floating point) values, possibly at a loss of	724	represented as numeric (floating point) values, possibly at a loss of
710	precision.	725	precision (in which case you might lose perfect roundtripping ability, but
711		726	the JSON number will still be re-encoded as a JSON number).
712	This might create round-tripping problems as numbers might become strings,
713	but as Perl is typeless there is no other way to do it.
714		727
715	=item true, false	728	=item true, false
716		729
717	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,	730	These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,
718	respectively. They are overloaded to act almost exactly like the numbers	731	respectively. They are overloaded to act almost exactly like the numbers
…		…
755	Other unblessed references are generally not allowed and will cause an	768	Other unblessed references are generally not allowed and will cause an
756	exception to be thrown, except for references to the integers C<0> and	769	exception to be thrown, except for references to the integers C<0> and
757	C<1>, which get turned into C<false> and C<true> atoms in JSON. You can	770	C<1>, which get turned into C<false> and C<true> atoms in JSON. You can
758	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.	771	also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability.
759		772
760	to_json [\0,JSON::XS::true] # yields [false,true]	773	encode_json [\0,JSON::XS::true] # yields [false,true]
761		774
762	=item JSON::XS::true, JSON::XS::false	775	=item JSON::XS::true, JSON::XS::false
763		776
764	These special values become JSON true and JSON false values,	777	These special values become JSON true and JSON false values,
765	respectively. You can also use C<\1> and C<\0> directly if you want.	778	respectively. You can also use C<\1> and C<\0> directly if you want.
766		779
767	=item blessed objects	780	=item blessed objects
768		781
769	Blessed objects are not allowed. JSON::XS currently tries to encode their	782	Blessed objects are not directly representable in JSON. See the
770	underlying representation (hash- or arrayref), but this behaviour might	783	C<allow_blessed> and C<convert_blessed> methods on various options on
771	change in future versions.	784	how to deal with this: basically, you can choose between throwing an
		785	exception, encoding the reference as if it weren't blessed, or provide
		786	your own serialiser method.
772		787
773	=item simple scalars	788	=item simple scalars
774		789
775	Simple Perl scalars (any scalar that is not a reference) are the most	790	Simple Perl scalars (any scalar that is not a reference) are the most
776	difficult objects to encode: JSON::XS will encode undefined scalars as	791	difficult objects to encode: JSON::XS will encode undefined scalars as
777	JSON null value, scalars that have last been used in a string context	792	JSON C<null> values, scalars that have last been used in a string context
778	before encoding as JSON strings and anything else as number value:	793	before encoding as JSON strings, and anything else as number value:
779		794
780	# dump as number	795	# dump as number
781	to_json [2] # yields [2]	796	encode_json [2] # yields [2]
782	to_json [-3.0e17] # yields [-3e+17]	797	encode_json [-3.0e17] # yields [-3e+17]
783	my $value = 5; to_json [$value] # yields [5]	798	my $value = 5; encode_json [$value] # yields [5]
784		799
785	# used as string, so dump as string	800	# used as string, so dump as string
786	print $value;	801	print $value;
787	to_json [$value] # yields ["5"]	802	encode_json [$value] # yields ["5"]
788		803
789	# undef becomes null	804	# undef becomes null
790	to_json [undef] # yields [null]	805	encode_json [undef] # yields [null]
791		806
792	You can force the type to be a JSON string by stringifying it:	807	You can force the type to be a JSON string by stringifying it:
793		808
794	my $x = 3.1; # some variable containing a number	809	my $x = 3.1; # some variable containing a number
795	"$x"; # stringified	810	"$x"; # stringified
…		…
801	my $x = "3"; # some variable containing a string	816	my $x = "3"; # some variable containing a string
802	$x += 0; # numify it, ensuring it will be dumped as a number	817	$x += 0; # numify it, ensuring it will be dumped as a number
803	$x *= 1; # same thing, the choice is yours.	818	$x *= 1; # same thing, the choice is yours.
804		819
805	You can not currently force the type in other, less obscure, ways. Tell me	820	You can not currently force the type in other, less obscure, ways. Tell me
806	if you need this capability.	821	if you need this capability (but don't forget to explain why its needed
		822	:).
		823
		824	=back
		825
		826
		827	=head1 ENCODING/CODESET FLAG NOTES
		828
		829	The interested reader might have seen a number of flags that signify
		830	encodings or codesets - C<utf8>, C<latin1> and C<ascii>. There seems to be
		831	some confusion on what these do, so here is a short comparison:
		832
		833	C<utf8> controls wether the JSON text created by C<encode> (and expected
		834	by C<decode>) is UTF-8 encoded or not, while C<latin1> and C<ascii> only
		835	control wether C<encode> escapes character values outside their respective
		836	codeset range. Neither of these flags conflict with each other, although
		837	some combinations make less sense than others.
		838
		839	Care has been taken to make all flags symmetrical with respect to
		840	C<encode> and C<decode>, that is, texts encoded with any combination of
		841	these flag values will be correctly decoded when the same flags are used
		842	- in general, if you use different flag settings while encoding vs. when
		843	decoding you likely have a bug somewhere.
		844
		845	Below comes a verbose discussion of these flags. Note that a "codeset" is
		846	simply an abstract set of character-codepoint pairs, while an encoding
		847	takes those codepoint numbers and I<encodes> them, in our case into
		848	octets. Unicode is (among other things) a codeset, UTF-8 is an encoding,
		849	and ISO-8859-1 (= latin 1) and ASCII are both codesets I<and> encodings at
		850	the same time, which can be confusing.
		851
		852	=over 4
		853
		854	=item C<utf8> flag disabled
		855
		856	When C<utf8> is disabled (the default), then C<encode>/C<decode> generate
		857	and expect Unicode strings, that is, characters with high ordinal Unicode
		858	values (> 255) will be encoded as such characters, and likewise such
		859	characters are decoded as-is, no canges to them will be done, except
		860	"(re-)interpreting" them as Unicode codepoints or Unicode characters,
		861	respectively (to Perl, these are the same thing in strings unless you do
		862	funny/weird/dumb stuff).
		863
		864	This is useful when you want to do the encoding yourself (e.g. when you
		865	want to have UTF-16 encoded JSON texts) or when some other layer does
		866	the encoding for you (for example, when printing to a terminal using a
		867	filehandle that transparently encodes to UTF-8 you certainly do NOT want
		868	to UTF-8 encode your data first and have Perl encode it another time).
		869
		870	=item C<utf8> flag enabled
		871
		872	If the C<utf8>-flag is enabled, C<encode>/C<decode> will encode all
		873	characters using the corresponding UTF-8 multi-byte sequence, and will
		874	expect your input strings to be encoded as UTF-8, that is, no "character"
		875	of the input string must have any value > 255, as UTF-8 does not allow
		876	that.
		877
		878	The C<utf8> flag therefore switches between two modes: disabled means you
		879	will get a Unicode string in Perl, enabled means you get an UTF-8 encoded
		880	octet/binary string in Perl.
		881
		882	=item C<latin1> or C<ascii> flags enabled
		883
		884	With C<latin1> (or C<ascii>) enabled, C<encode> will escape characters
		885	with ordinal values > 255 (> 127 with C<ascii>) and encode the remaining
		886	characters as specified by the C<utf8> flag.
		887
		888	If C<utf8> is disabled, then the result is also correctly encoded in those
		889	character sets (as both are proper subsets of Unicode, meaning that a
		890	Unicode string with all character values < 256 is the same thing as a
		891	ISO-8859-1 string, and a Unicode string with all character values < 128 is
		892	the same thing as an ASCII string in Perl).
		893
		894	If C<utf8> is enabled, you still get a correct UTF-8-encoded string,
		895	regardless of these flags, just some more characters will be escaped using
		896	C<\uXXXX> then before.
		897
		898	Note that ISO-8859-1-I<encoded> strings are not compatible with UTF-8
		899	encoding, while ASCII-encoded strings are. That is because the ISO-8859-1
		900	encoding is NOT a subset of UTF-8 (despite the ISO-8859-1 I<codeset> being
		901	a subset of Unicode), while ASCII is.
		902
		903	Surprisingly, C<decode> will ignore these flags and so treat all input
		904	values as governed by the C<utf8> flag. If it is disabled, this allows you
		905	to decode ISO-8859-1- and ASCII-encoded strings, as both strict subsets of
		906	Unicode. If it is enabled, you can correctly decode UTF-8 encoded strings.
		907
		908	So neither C<latin1> nor C<ascii> are incompatible with the C<utf8> flag -
		909	they only govern when the JSON output engine escapes a character or not.
		910
		911	The main use for C<latin1> is to relatively efficiently store binary data
		912	as JSON, at the expense of breaking compatibility with most JSON decoders.
		913
		914	The main use for C<ascii> is to force the output to not contain characters
		915	with values > 127, which means you can interpret the resulting string
		916	as UTF-8, ISO-8859-1, ASCII, KOI8-R or most about any character set and
		917	8-bit-encoding, and still get the same data structure back. This is useful
		918	when your channel for JSON transfer is not 8-bit clean or the encoding
		919	might be mangled in between (e.g. in mail), and works because ASCII is a
		920	proper subset of most 8-bit and multibyte encodings in use in the world.
807		921
808	=back	922	=back
809		923
810		924
811	=head1 COMPARISON	925	=head1 COMPARISON
…		…
815	problems (or pleasures) I encountered with various existing JSON modules,	929	problems (or pleasures) I encountered with various existing JSON modules,
816	followed by some benchmark values. JSON::XS was designed not to suffer	930	followed by some benchmark values. JSON::XS was designed not to suffer
817	from any of these problems or limitations.	931	from any of these problems or limitations.
818		932
819	=over 4	933	=over 4
		934
		935	=item JSON 2.xx
		936
		937	A marvellous piece of engineering, this module either uses JSON::XS
		938	directly when available (so will be 100% compatible with it, including
		939	speed), or it uses JSON::PP, which is basically JSON::XS translated to
		940	Pure Perl, which should be 100% compatible with JSON::XS, just a bit
		941	slower.
		942
		943	You cannot really lose by using this module, especially as it tries very
		944	hard to work even with ancient Perl versions, while JSON::XS does not.
820		945
821	=item JSON 1.07	946	=item JSON 1.07
822		947
823	Slow (but very portable, as it is written in pure Perl).	948	Slow (but very portable, as it is written in pure Perl).
824		949
…		…
895	=back	1020	=back
896		1021
897		1022
898	=head2 JSON and YAML	1023	=head2 JSON and YAML
899		1024
900	You often hear that JSON is a subset (or a close subset) of YAML. This is,	1025	You often hear that JSON is a subset of YAML. This is, however, a mass
901	however, a mass hysteria and very far from the truth. In general, there is	1026	hysteria(*) and very far from the truth. In general, there is no way to
902	no way to configure JSON::XS to output a data structure as valid YAML.	1027	configure JSON::XS to output a data structure as valid YAML that works for
		1028	all cases.
903		1029
904	If you really must use JSON::XS to generate YAML, you should use this	1030	If you really must use JSON::XS to generate YAML, you should use this
905	algorithm (subject to change in future versions):	1031	algorithm (subject to change in future versions):
906		1032
907	my $to_yaml = JSON::XS->new->utf8->space_after (1);	1033	my $to_yaml = JSON::XS->new->utf8->space_after (1);
908	my $yaml = $to_yaml->encode ($ref) . "\n";	1034	my $yaml = $to_yaml->encode ($ref) . "\n";
909		1035
910	This will usually generate JSON texts that also parse as valid	1036	This will I<usually> generate JSON texts that also parse as valid
911	YAML. Please note that YAML has hardcoded limits on (simple) object key	1037	YAML. Please note that YAML has hardcoded limits on (simple) object key
912	lengths that JSON doesn't have, so you should make sure that your hash	1038	lengths that JSON doesn't have and also has different and incompatible
		1039	unicode handling, so you should make sure that your hash keys are
913	keys are noticeably shorter than the 1024 characters YAML allows.	1040	noticeably shorter than the 1024 "stream characters" YAML allows and that
		1041	you do not have codepoints with values outside the Unicode BMP (basic
		1042	multilingual page). YAML also does not allow C<\/> sequences in strings
		1043	(which JSON::XS does not I<currently> generate).
914		1044
915	There might be other incompatibilities that I am not aware of. In general	1045	There might be other incompatibilities that I am not aware of (or the YAML
		1046	specification has been changed yet again - it does so quite often). In
916	you should not try to generate YAML with a JSON generator or vice versa,	1047	general you should not try to generate YAML with a JSON generator or vice
917	or try to parse JSON with a YAML parser or vice versa: chances are high	1048	versa, or try to parse JSON with a YAML parser or vice versa: chances are
918	that you will run into severe interoperability problems.	1049	high that you will run into severe interoperability problems when you
		1050	least expect it.
		1051
		1052	=over 4
		1053
		1054	=item (*)
		1055
		1056	This is spread actively by the YAML team, however. For many years now they
		1057	claim YAML were a superset of JSON, even when proven otherwise.
		1058
		1059	Even the author of this manpage was at some point accused of providing
		1060	"incorrect" information, despite the evidence presented (claims ranged
		1061	from "your documentation contains inaccurate and negative statements about
		1062	YAML" (the only negative comment is this footnote, and it didn't exist
		1063	back then; the question on which claims were inaccurate was never answered
		1064	etc.) to "the YAML spec is not up-to-date" (the real and supposedly
		1065	JSON-compatible spec is apparently not currently publicly available)
		1066	to actual requests to replace this section by incorrect information,
		1067	suppressing information about the real problem).
		1068
		1069	So whenever you are told that YAML was a superset of JSON, first check
		1070	wether it is really true (it might be when you check it, but it certainly
		1071	was not true when this was written). I would much prefer if the YAML team
		1072	would spent their time on actually making JSON compatibility a truth
		1073	(JSON, after all, has a very small and simple specification) instead of
		1074	trying to lobby/force people into reporting untruths.
		1075
		1076	=back
919		1077
920		1078
921	=head2 SPEED	1079	=head2 SPEED
922		1080
923	It seems that JSON::XS is surprisingly fast, as shown in the following	1081	It seems that JSON::XS is surprisingly fast, as shown in the following
…		…
1000		1158
1001	Third, JSON::XS recurses using the C stack when decoding objects and	1159	Third, JSON::XS recurses using the C stack when decoding objects and
1002	arrays. The C stack is a limited resource: for instance, on my amd64	1160	arrays. The C stack is a limited resource: for instance, on my amd64
1003	machine with 8MB of stack size I can decode around 180k nested arrays but	1161	machine with 8MB of stack size I can decode around 180k nested arrays but
1004	only 14k nested JSON objects (due to perl itself recursing deeply on croak	1162	only 14k nested JSON objects (due to perl itself recursing deeply on croak
1005	to free the temporary). If that is exceeded, the program crashes. to be	1163	to free the temporary). If that is exceeded, the program crashes. To be
1006	conservative, the default nesting limit is set to 512. If your process	1164	conservative, the default nesting limit is set to 512. If your process
1007	has a smaller stack, you should adjust this setting accordingly with the	1165	has a smaller stack, you should adjust this setting accordingly with the
1008	C<max_depth> method.	1166	C<max_depth> method.
1009		1167
1010	And last but least, something else could bomb you that I forgot to think	1168	Something else could bomb you, too, that I forgot to think of. In that
1011	of. In that case, you get to keep the pieces. I am always open for hints,	1169	case, you get to keep the pieces. I am always open for hints, though...
1012	though...	1170
		1171	Also keep in mind that JSON::XS might leak contents of your Perl data
		1172	structures in its error messages, so when you serialise sensitive
		1173	information you might want to make sure that exceptions thrown by JSON::XS
		1174	will not end up in front of untrusted eyes.
1013		1175
1014	If you are using JSON::XS to return packets to consumption	1176	If you are using JSON::XS to return packets to consumption
1015	by JavaScript scripts in a browser you should have a look at	1177	by JavaScript scripts in a browser you should have a look at
1016	L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether	1178	L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether
1017	you are vulnerable to some common attack vectors (which really are browser	1179	you are vulnerable to some common attack vectors (which really are browser
1018	design bugs, but it is still you who will have to deal with it, as major	1180	design bugs, but it is still you who will have to deal with it, as major
1019	browser developers care only for features, not about doing security	1181	browser developers care only for features, not about getting security
1020	right).	1182	right).
1021		1183
1022		1184
1023	=head1 THREADS	1185	=head1 THREADS
1024		1186

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Comparing JSON-XS/XS.pm (file contents): Revision 1.77 by root, Tue Dec 4 10:37:42 2007 UTC vs. Revision 1.86 by root, Wed Mar 19 03:17:38 2008 UTC

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Comparing JSON-XS/XS.pm (file contents):
Revision 1.77 by root, Tue Dec 4 10:37:42 2007 UTC vs.
Revision 1.86 by root, Wed Mar 19 03:17:38 2008 UTC