--- JSON-XS/XS.pm 2008/03/26 01:43:14 1.97 +++ JSON-XS/XS.pm 2013/10/29 00:06:40 1.145 @@ -1,9 +1,9 @@ =head1 NAME -=encoding utf-8 - JSON::XS - JSON serialising/deserialising, done correctly and fast +=encoding utf-8 + JSON::XS - 正しくて高速な JSON シリアライザ/デシリアライザ (http://fleur.hio.jp/perldoc/mix/lib/JSON/XS.html) @@ -39,7 +39,7 @@ Beginning with version 2.0 of the JSON module, when both JSON and JSON::XS are installed, then JSON will fall back on JSON::XS (this can be -overriden) with no overhead due to emulation (by inheritign constructor +overridden) with no overhead due to emulation (by inheriting constructor and methods). If JSON::XS is not available, it will fall back to the compatible JSON::PP module as backend, so using JSON instead of JSON::XS gives you a portable JSON API that can be fast when you need and doesn't @@ -51,8 +51,6 @@ their maintainers are unresponsive, gone missing, or not listening to bug reports for other reasons. -See COMPARISON, below, for a comparison to some other JSON modules. - See MAPPING, below, on how JSON::XS maps perl values to JSON values and vice versa. @@ -67,11 +65,11 @@ =item * round-trip integrity -When you serialise a perl data structure using only datatypes supported -by JSON, the deserialised data structure is identical on the Perl level. -(e.g. the string "2.0" doesn't suddenly become "2" just because it looks -like a number). There minor I exceptions to this, read the MAPPING -section below to learn about those. +When you serialise a perl data structure using only data types supported +by JSON and Perl, the deserialised data structure is identical on the Perl +level. (e.g. the string "2.0" doesn't suddenly become "2" just because +it looks like a number). There I minor exceptions to this, read the +MAPPING section below to learn about those. =item * strict checking of JSON correctness @@ -86,13 +84,13 @@ =item * simple to use -This module has both a simple functional interface as well as an objetc -oriented interface interface. +This module has both a simple functional interface as well as an object +oriented interface. =item * reasonably versatile output formats You can choose between the most compact guaranteed-single-line format -possible (nice for simple line-based protocols), a pure-ascii format +possible (nice for simple line-based protocols), a pure-ASCII format (for when your transport is not 8-bit clean, still supports the whole Unicode range), or a pretty-printed format (for when you want to read that stuff). Or you can combine those features in whatever way you like. @@ -103,26 +101,18 @@ package JSON::XS; -use strict; +use common::sense; -our $VERSION = '2.1'; +our $VERSION = '3.0'; our @ISA = qw(Exporter); -our @EXPORT = qw(encode_json decode_json to_json from_json); - -sub to_json($) { - require Carp; - 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"); -} - -sub from_json($) { - require Carp; - 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"); -} +our @EXPORT = qw(encode_json decode_json); use Exporter; use XSLoader; +use Types::Serialiser (); + =head1 FUNCTIONAL INTERFACE The following convenience methods are provided by this module. They are @@ -139,7 +129,7 @@ $json_text = JSON::XS->new->utf8->encode ($perl_scalar) -except being faster. +Except being faster. =item $perl_scalar = decode_json $json_text @@ -151,16 +141,7 @@ $perl_scalar = JSON::XS->new->utf8->decode ($json_text) -except being faster. - -=item $is_boolean = JSON::XS::is_bool $scalar - -Returns true if the passed scalar represents either JSON::XS::true or -JSON::XS::false, two constants that act like C<1> and C<0>, respectively -and are used to represent JSON C and C values in Perl. - -See MAPPING, below, for more information on how JSON values are mapped to -Perl. +Except being faster. =back @@ -199,7 +180,7 @@ exist. =item 4. A "Unicode String" is simply a string where each character can be -validly interpreted as a Unicode codepoint. +validly interpreted as a Unicode code point. If you have UTF-8 encoded data, it is no longer a Unicode string, but a Unicode string encoded in UTF-8, giving you a binary string. @@ -436,7 +417,8 @@ If C<$enable> is false, then the C method will output key-value pairs in the order Perl stores them (which will likely change between runs -of the same script). +of the same script, and can change even within the same run from 5.18 +onwards). This option is useful if you want the same data structure to be encoded as the same JSON text (given the same overall settings). If it is disabled, @@ -445,6 +427,8 @@ This setting has no effect when decoding JSON texts. +This setting has currently no effect on tied hashes. + =item $json = $json->allow_nonref ([$enable]) =item $enabled = $json->get_allow_nonref @@ -465,6 +449,22 @@ JSON::XS->new->allow_nonref->encode ("Hello, World!") => "Hello, World!" +=item $json = $json->allow_unknown ([$enable]) + +=item $enabled = $json->get_allow_unknown + +If C<$enable> is true (or missing), then C will I throw an +exception when it encounters values it cannot represent in JSON (for +example, filehandles) but instead will encode a JSON C value. Note +that blessed objects are not included here and are handled separately by +c. + +If C<$enable> is false (the default), then C will throw an +exception when it encounters anything it cannot encode as JSON. + +This option does not affect C in any way, and it is recommended to +leave it off unless you know your communications partner. + =item $json = $json->allow_blessed ([$enable]) =item $enabled = $json->get_allow_blessed @@ -614,9 +614,9 @@ =item $max_depth = $json->get_max_depth Sets the maximum nesting level (default C<512>) accepted while encoding -or decoding. If the JSON text or Perl data structure has an equal or -higher nesting level then this limit, then the encoder and decoder will -stop and croak at that point. +or decoding. If a higher nesting level is detected in JSON text or a Perl +data structure, then the encoder and decoder will stop and croak at that +point. Nesting level is defined by number of hash- or arrayrefs that the encoder needs to traverse to reach a given point or the number of C<{> or C<[> @@ -626,9 +626,12 @@ Setting the maximum depth to one disallows any nesting, so that ensures that the object is only a single hash/object or array. -The argument to C will be rounded up to the next highest power -of two. If no argument is given, the highest possible setting will be -used, which is rarely useful. +If no argument is given, the highest possible setting will be used, which +is rarely useful. + +Note that nesting is implemented by recursion in C. The default value has +been chosen to be as large as typical operating systems allow without +crashing. See SECURITY CONSIDERATIONS, below, for more info on why this is useful. @@ -638,34 +641,25 @@ Set the maximum length a JSON text may have (in bytes) where decoding is being attempted. The default is C<0>, meaning no limit. When C -is called on a string longer then this number of characters it will not +is called on a string that is longer then this many bytes, it will not attempt to decode the string but throw an exception. This setting has no effect on C (yet). -The argument to C will be rounded up to the next B -power of two (so may be more than requested). If no argument is given, the -limit check will be deactivated (same as when C<0> is specified). +If no argument is given, the limit check will be deactivated (same as when +C<0> is specified). See SECURITY CONSIDERATIONS, below, for more info on why this is useful. =item $json_text = $json->encode ($perl_scalar) -Converts the given Perl data structure (a simple scalar or a reference -to a hash or array) to its JSON representation. Simple scalars will be -converted into JSON string or number sequences, while references to arrays -become JSON arrays and references to hashes become JSON objects. Undefined -Perl values (e.g. C) become JSON C values. Neither C -nor C values will be generated. +Converts the given Perl value or data structure to its JSON +representation. Croaks on error. =item $perl_scalar = $json->decode ($json_text) The opposite of C: expects a JSON text and tries to parse it, returning the resulting simple scalar or reference. Croaks on error. -JSON numbers and strings become simple Perl scalars. JSON arrays become -Perl arrayrefs and JSON objects become Perl hashrefs. C becomes -C<1>, C becomes C<0> and C becomes C. - =item ($perl_scalar, $characters) = $json->decode_prefix ($json_text) This works like the C method, but instead of raising an exception @@ -674,8 +668,7 @@ so far. This is useful if your JSON texts are not delimited by an outer protocol -(which is not the brightest thing to do in the first place) and you need -to know where the JSON text ends. +and you need to know where the JSON text ends. JSON::XS->new->decode_prefix ("[1] the tail") => ([], 3) @@ -685,19 +678,25 @@ =head1 INCREMENTAL PARSING -[This section is still EXPERIMENTAL] - In some cases, there is the need for incremental parsing of JSON texts. While this module always has to keep both JSON text and resulting Perl data structure in memory at one time, it does allow you to parse a JSON stream incrementally. It does so by accumulating text until it has a full JSON object, which it then can decode. This process is similar to -using C to see if a full JSON object is available, but is -much more efficient (JSON::XS will only attempt to parse the JSON text -once it is sure it has enough text to get a decisive result, using a very -simple but truly incremental parser). +using C to see if a full JSON object is available, but +is much more efficient (and can be implemented with a minimum of method +calls). + +JSON::XS will only attempt to parse the JSON text once it is sure it +has enough text to get a decisive result, using a very simple but +truly incremental parser. This means that it sometimes won't stop as +early as the full parser, for example, it doesn't detect mismatched +parentheses. The only thing it guarantees is that it starts decoding as +soon as a syntactically valid JSON text has been seen. This means you need +to set resource limits (e.g. C) to ensure the parser will stop +parsing in the presence if syntax errors. -The following two methods deal with this. +The following methods implement this incremental parser. =over 4 @@ -718,7 +717,7 @@ exactly I JSON object. If that is successful, it will return this object, otherwise it will return C. If there is a parse error, this method will croak just as C would do (one can then use -C to skip the errornous part). This is the most common way of +C to skip the erroneous part). This is the most common way of using the method. And finally, in list context, it will try to extract as many objects @@ -729,6 +728,11 @@ case. Note that in this case, any previously-parsed JSON texts will be lost. +Example: Parse some JSON arrays/objects in a given string and return +them. + + my @objs = JSON::XS->new->incr_parse ("[5][7][1,2]"); + =item $lvalue_string = $json->incr_text This method returns the currently stored JSON fragment as an lvalue, that @@ -745,20 +749,33 @@ =item $json->incr_skip -This will reset the state of the incremental parser and will remove the -parsed text from the input buffer. This is useful after C -died, in which case the input buffer and incremental parser state is left -unchanged, to skip the text parsed so far and to reset the parse state. +This will reset the state of the incremental parser and will remove +the parsed text from the input buffer so far. This is useful after +C died, in which case the input buffer and incremental parser +state is left unchanged, to skip the text parsed so far and to reset the +parse state. + +The difference to C is that only text until the parse error +occurred is removed. + +=item $json->incr_reset + +This completely resets the incremental parser, that is, after this call, +it will be as if the parser had never parsed anything. + +This is useful if you want to repeatedly parse JSON objects and want to +ignore any trailing data, which means you have to reset the parser after +each successful decode. =back =head2 LIMITATIONS All options that affect decoding are supported, except -C. The reason for this is that it cannot be made to -work sensibly: JSON objects and arrays are self-delimited, i.e. you can concatenate -them back to back and still decode them perfectly. This does not hold true -for JSON numbers, however. +C. The reason for this is that it cannot be made to work +sensibly: JSON objects and arrays are self-delimited, i.e. you can +concatenate them back to back and still decode them perfectly. This does +not hold true for JSON numbers, however. For example, is the string C<1> a single JSON number, or is it simply the start of C<12>? Or is C<12> a single JSON number, or the concatenation @@ -947,24 +964,45 @@ a numeric (floating point) value if that is possible without loss of precision. Otherwise it will preserve the number as a string value (in which case you lose roundtripping ability, as the JSON number will be -re-encoded toa JSON string). +re-encoded to a JSON string). Numbers containing a fractional or exponential part will always be represented as numeric (floating point) values, possibly at a loss of precision (in which case you might lose perfect roundtripping ability, but the JSON number will still be re-encoded as a JSON number). +Note that precision is not accuracy - binary floating point values cannot +represent most decimal fractions exactly, and when converting from and to +floating point, JSON::XS only guarantees precision up to but not including +the least significant bit. + =item true, false -These JSON atoms become C and C, -respectively. They are overloaded to act almost exactly like the numbers -C<1> and C<0>. You can check whether a scalar is a JSON boolean by using -the C function. +These JSON atoms become C and +C, respectively. They are overloaded to act +almost exactly like the numbers C<1> and C<0>. You can check whether +a scalar is a JSON boolean by using the C +function (after C, of course). =item null A JSON null atom becomes C in Perl. +=item shell-style comments (C<< # I >>) + +As a nonstandard extension to the JSON syntax that is enabled by the +C setting, shell-style comments are allowed. They can start +anywhere outside strings and go till the end of the line. + +=item tagged values (C<< (I)I >>). + +Another nonstandard extension to the JSON syntax, enabled with the +C setting, are tagged values. In this implementation, the +I must be a perl package/class name encoded as a JSON string, and the +I must be a JSON array encoding optional constructor arguments. + +See "OBJECT SERIALISATION", below, for details. + =back @@ -978,15 +1016,13 @@ =item hash references -Perl hash references become JSON objects. As there is no inherent ordering -in hash keys (or JSON objects), they will usually be encoded in a -pseudo-random order that can change between runs of the same program but -stays generally the same within a single run of a program. JSON::XS can -optionally sort the hash keys (determined by the I flag), so -the same datastructure will serialise to the same JSON text (given same -settings and version of JSON::XS), but this incurs a runtime overhead -and is only rarely useful, e.g. when you want to compare some JSON text -against another for equality. +Perl hash references become JSON objects. As there is no inherent +ordering in hash keys (or JSON objects), they will usually be encoded +in a pseudo-random order. JSON::XS can optionally sort the hash keys +(determined by the I flag), so the same datastructure will +serialise to the same JSON text (given same settings and version of +JSON::XS), but this incurs a runtime overhead and is only rarely useful, +e.g. when you want to compare some JSON text against another for equality. =item array references @@ -996,23 +1032,26 @@ Other unblessed references are generally not allowed and will cause an exception to be thrown, except for references to the integers C<0> and -C<1>, which get turned into C and C atoms in JSON. You can -also use C and C to improve readability. +C<1>, which get turned into C and C atoms in JSON. + +Since C uses the boolean model from L, you +can also C and then use C +and C to improve readability. - encode_json [\0,JSON::XS::true] # yields [false,true] + use Types::Serialiser; + encode_json [\0, Types::Serialiser::true] # yields [false,true] -=item JSON::XS::true, JSON::XS::false +=item Types::Serialiser::true, Types::Serialiser::false -These special values become JSON true and JSON false values, -respectively. You can also use C<\1> and C<\0> directly if you want. +These special values from the L module become JSON true +and JSON false values, respectively. You can also use C<\1> and C<\0> +directly if you want. =item blessed objects -Blessed objects are not directly representable in JSON. See the -C and C methods on various options on -how to deal with this: basically, you can choose between throwing an -exception, encoding the reference as if it weren't blessed, or provide -your own serialiser method. +Blessed objects are not directly representable in JSON, but C +allows various ways of handling objects. See "OBJECT SERIALISATION", +below, for details. =item simple scalars @@ -1050,8 +1089,116 @@ if you need this capability (but don't forget to explain why it's needed :). +Note that numerical precision has the same meaning as under Perl (so +binary to decimal conversion follows the same rules as in Perl, which +can differ to other languages). Also, your perl interpreter might expose +extensions to the floating point numbers of your platform, such as +infinities or NaN's - these cannot be represented in JSON, and it is an +error to pass those in. + =back +=head2 OBJECT SERIALISATION + +As JSON cannot directly represent Perl objects, you have to choose between +a pure JSON representation (without the ability to deserialise the object +automatically again), and a nonstandard extension to the JSON syntax, +tagged values. + +=head3 SERIALISATION + +What happens when C encounters a Perl object depends on the +C, C and C settings, which are +used in this order: + +=over 4 + +=item 1. C is enabled and object has a C method. + +In this case, C uses the L object +serialisation protocol to create a tagged JSON value, using a nonstandard +extension to the JSON syntax. + +This works by invoking the C method on the object, with the first +argument being the object to serialise, and the second argument being the +constant string C to distinguish it from other serialisers. + +The C method can return any number of values (i.e. zero or +more). These values and the paclkage/classname of the object will then be +encoded as a tagged JSON value in the following format: + + ("classname")[FREEZE return values...] + +For example, the hypothetical C C method might use the +objects C and C members to encode the object: + + sub My::Object::FREEZE { + my ($self, $serialiser) = @_; + + ($self->{type}, $self->{id}) + } + +=item 2. C is enabled and object has a C method. + +In this case, the C method of the object is invoked in scalar +context. It must return a single scalar that can be directly encoded into +JSON. This scalar replaces the object in the JSON text. + +For example, the following C method will convert all L +objects to JSON strings when serialised. The fatc that these values +originally were L objects is lost. + + sub URI::TO_JSON { + my ($uri) = @_; + $uri->as_string + } + +=item 3. C is enabled. + +The object will be serialised as a JSON null value. + +=item 4. none of the above + +If none of the settings are enabled or the respective methods are missing, +C throws an exception. + +=back + +=head3 DESERIALISATION + +For deserialisation there are only two cases to consider: either +nonstandard tagging was used, in which case C decides, +or objects cannot be automatically be deserialised, in which +case you can use postprocessing or the C or +C callbacks to get some real objects our of +your JSON. + +This section only considers the tagged value case: I a tagged JSON object +is encountered during decoding and C is disabled, a parse +error will result (as if tagged values were not part of the grammar). + +If C is enabled, C will look up the C method +of the package/classname used during serialisation. If there is no such +method, the decoding will fail with an error. + +Otherwise, the C method is invoked with the classname as first +argument, the constant string C as second argument, and all the +values from the JSON array (the values originally returned by the +C method) as remaining arguments. + +The method must then return the object. While technically you can return +any Perl scalar, you might have to enable the C setting to +make that work in all cases, so better return an actual blessed reference. + +As an example, let's implement a C function that regenerates the +C from the C example earlier: + + sub My::Object::THAW { + my ($class, $serialiser, $type, $id) = @_; + + $class->new (type => $type, id => $id) + } + =head1 ENCODING/CODESET FLAG NOTES @@ -1085,7 +1232,7 @@ When C is disabled (the default), then C/C generate and expect Unicode strings, that is, characters with high ordinal Unicode values (> 255) will be encoded as such characters, and likewise such -characters are decoded as-is, no canges to them will be done, except +characters are decoded as-is, no changes to them will be done, except "(re-)interpreting" them as Unicode codepoints or Unicode characters, respectively (to Perl, these are the same thing in strings unless you do funny/weird/dumb stuff). @@ -1151,6 +1298,71 @@ =back +=head2 JSON and ECMAscript + +JSON syntax is based on how literals are represented in javascript (the +not-standardised predecessor of ECMAscript) which is presumably why it is +called "JavaScript Object Notation". + +However, JSON is not a subset (and also not a superset of course) of +ECMAscript (the standard) or javascript (whatever browsers actually +implement). + +If you want to use javascript's C function to "parse" JSON, you +might run into parse errors for valid JSON texts, or the resulting data +structure might not be queryable: + +One of the problems is that U+2028 and U+2029 are valid characters inside +JSON strings, but are not allowed in ECMAscript string literals, so the +following Perl fragment will not output something that can be guaranteed +to be parsable by javascript's C: + + use JSON::XS; + + print encode_json [chr 0x2028]; + +The right fix for this is to use a proper JSON parser in your javascript +programs, and not rely on C (see for example Douglas Crockford's +F parser). + +If this is not an option, you can, as a stop-gap measure, simply encode to +ASCII-only JSON: + + use JSON::XS; + + print JSON::XS->new->ascii->encode ([chr 0x2028]); + +Note that this will enlarge the resulting JSON text quite a bit if you +have many non-ASCII characters. You might be tempted to run some regexes +to only escape U+2028 and U+2029, e.g.: + + # DO NOT USE THIS! + my $json = JSON::XS->new->utf8->encode ([chr 0x2028]); + $json =~ s/\xe2\x80\xa8/\\u2028/g; # escape U+2028 + $json =~ s/\xe2\x80\xa9/\\u2029/g; # escape U+2029 + print $json; + +Note that I: the above only works for U+2028 and +U+2029 and thus only for fully ECMAscript-compliant parsers. Many existing +javascript implementations, however, have issues with other characters as +well - using C naively simply I cause problems. + +Another problem is that some javascript implementations reserve +some property names for their own purposes (which probably makes +them non-ECMAscript-compliant). For example, Iceweasel reserves the +C<__proto__> property name for its own purposes. + +If that is a problem, you could parse try to filter the resulting JSON +output for these property strings, e.g.: + + $json =~ s/"__proto__"\s*:/"__proto__renamed":/g; + +This works because C<__proto__> is not valid outside of strings, so every +occurrence of C<"__proto__"\s*:> must be a string used as property name. + +If you know of other incompatibilities, please let me know. + + =head2 JSON and YAML You often hear that JSON is a subset of YAML. This is, however, a mass @@ -1168,12 +1380,12 @@ This will I generate JSON texts that also parse as valid YAML. Please note that YAML has hardcoded limits on (simple) object key lengths that JSON doesn't have and also has different and incompatible -unicode handling, so you should make sure that your hash keys are -noticeably shorter than the 1024 "stream characters" YAML allows and that -you do not have characters with codepoint values outside the Unicode BMP -(basic multilingual page). YAML also does not allow C<\/> sequences in -strings (which JSON::XS does not I generate, but other JSON -generators might). +unicode character escape syntax, so you should make sure that your hash +keys are noticeably shorter than the 1024 "stream characters" YAML allows +and that you do not have characters with codepoint values outside the +Unicode BMP (basic multilingual page). YAML also does not allow C<\/> +sequences in strings (which JSON::XS does not I generate, but +other JSON generators might). There might be other incompatibilities that I am not aware of (or the YAML specification has been changed yet again - it does so quite often). In @@ -1202,6 +1414,12 @@ real compatibility for many I and trying to silence people who point out that it isn't true. +Addendum/2009: the YAML 1.2 spec is still incompatible with JSON, even +though the incompatibilities have been documented (and are known to Brian) +for many years and the spec makes explicit claims that YAML is a superset +of JSON. It would be so easy to fix, but apparently, bullying people and +corrupting userdata is so much easier. + =back @@ -1216,50 +1434,50 @@ a very short single-line JSON string (also available at L). - {"method": "handleMessage", "params": ["user1", "we were just talking"], \ - "id": null, "array":[1,11,234,-5,1e5,1e7, true, false]} + {"method": "handleMessage", "params": ["user1", + "we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7, + 1, 0]} It shows the number of encodes/decodes per second (JSON::XS uses the functional interface, while JSON::XS/2 uses the OO interface with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables -shrink). Higher is better: +shrink. JSON::DWIW/DS uses the deserialise function, while JSON::DWIW::FJ +uses the from_json method). Higher is better: - module | encode | decode | - -----------|------------|------------| - JSON 1.x | 4990.842 | 4088.813 | - JSON::DWIW | 51653.990 | 71575.154 | - JSON::PC | 65948.176 | 74631.744 | - JSON::PP | 8931.652 | 3817.168 | - JSON::Syck | 24877.248 | 27776.848 | - JSON::XS | 388361.481 | 227951.304 | - JSON::XS/2 | 227951.304 | 218453.333 | - JSON::XS/3 | 338250.323 | 218453.333 | - Storable | 16500.016 | 135300.129 | - -----------+------------+------------+ - -That is, JSON::XS is about five times faster than JSON::DWIW on encoding, -about three times faster on decoding, and over forty times faster -than JSON, even with pretty-printing and key sorting. It also compares -favourably to Storable for small amounts of data. + module | encode | decode | + --------------|------------|------------| + JSON::DWIW/DS | 86302.551 | 102300.098 | + JSON::DWIW/FJ | 86302.551 | 75983.768 | + JSON::PP | 15827.562 | 6638.658 | + JSON::Syck | 63358.066 | 47662.545 | + JSON::XS | 511500.488 | 511500.488 | + JSON::XS/2 | 291271.111 | 388361.481 | + JSON::XS/3 | 361577.931 | 361577.931 | + Storable | 66788.280 | 265462.278 | + --------------+------------+------------+ + +That is, JSON::XS is almost six times faster than JSON::DWIW on encoding, +about five times faster on decoding, and over thirty to seventy times +faster than JSON's pure perl implementation. It also compares favourably +to Storable for small amounts of data. Using a longer test string (roughly 18KB, generated from Yahoo! Locals search API (L). - module | encode | decode | - -----------|------------|------------| - JSON 1.x | 55.260 | 34.971 | - JSON::DWIW | 825.228 | 1082.513 | - JSON::PC | 3571.444 | 2394.829 | - JSON::PP | 210.987 | 32.574 | - JSON::Syck | 552.551 | 787.544 | - JSON::XS | 5780.463 | 4854.519 | - JSON::XS/2 | 3869.998 | 4798.975 | - JSON::XS/3 | 5862.880 | 4798.975 | - Storable | 4445.002 | 5235.027 | - -----------+------------+------------+ + module | encode | decode | + --------------|------------|------------| + JSON::DWIW/DS | 1647.927 | 2673.916 | + JSON::DWIW/FJ | 1630.249 | 2596.128 | + JSON::PP | 400.640 | 62.311 | + JSON::Syck | 1481.040 | 1524.869 | + JSON::XS | 20661.596 | 9541.183 | + JSON::XS/2 | 10683.403 | 9416.938 | + JSON::XS/3 | 20661.596 | 9400.054 | + Storable | 19765.806 | 10000.725 | + --------------+------------+------------+ Again, JSON::XS leads by far (except for Storable which non-surprisingly -decodes faster). +decodes a bit faster). On large strings containing lots of high Unicode characters, some modules (such as JSON::PC) seem to decode faster than JSON::XS, but the result @@ -1305,11 +1523,19 @@ If you are using JSON::XS to return packets to consumption by JavaScript scripts in a browser you should have a look at -L to see whether -you are vulnerable to some common attack vectors (which really are browser -design bugs, but it is still you who will have to deal with it, as major -browser developers care only for features, not about getting security -right). +L to +see whether you are vulnerable to some common attack vectors (which really +are browser design bugs, but it is still you who will have to deal with +it, as major browser developers care only for features, not about getting +security right). + + +=head1 INTEROPERABILITY WITH OTHER MODULES + +C uses the L module to provide boolean +constants. That means that the JSON true and false values will be +comaptible to true and false values of iother modules that do the same, +such as L and L. =head1 THREADS @@ -1322,41 +1548,47 @@ (It might actually work, but you have been warned). +=head1 THE PERILS OF SETLOCALE + +Sometimes people avoid the Perl locale support and directly call the +system's setlocale function with C. + +This breaks both perl and modules such as JSON::XS, as stringification of +numbers no longer works correctly (e.g. C<$x = 0.1; print "$x"+1> might +print C<1>, and JSON::XS might output illegal JSON as JSON::XS relies on +perl to stringify numbers). + +The solution is simple: don't call C, or use it for only those +categories you need, such as C or C. + +If you need C, you should enable it only around the code that +actually needs it (avoiding stringification of numbers), and restore it +afterwards. + + =head1 BUGS While the goal of this module is to be correct, that unfortunately does -not mean it's bug-free, only that I think its design is bug-free. It is -still relatively early in its development. If you keep reporting bugs they -will be fixed swiftly, though. +not mean it's bug-free, only that I think its design is bug-free. If you +keep reporting bugs they will be fixed swiftly, though. Please refrain from using rt.cpan.org or any other bug reporting service. I put the contact address into my modules for a reason. =cut -our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; -our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; +BEGIN { + *true = \$Types::Serialiser::true; + *true = \&Types::Serialiser::true; + *false = \$Types::Serialiser::false; + *false = \&Types::Serialiser::false; + *is_bool = \&Types::Serialiser::is_bool; -sub true() { $true } -sub false() { $false } - -sub is_bool($) { - UNIVERSAL::isa $_[0], "JSON::XS::Boolean" -# or UNIVERSAL::isa $_[0], "JSON::Literal" + *JSON::XS::Boolean:: = *Types::Serialiser::Boolean::; } XSLoader::load "JSON::XS", $VERSION; -package JSON::XS::Boolean; - -use overload - "0+" => sub { ${$_[0]} }, - "++" => sub { $_[0] = ${$_[0]} + 1 }, - "--" => sub { $_[0] = ${$_[0]} - 1 }, - fallback => 1; - -1; - =head1 SEE ALSO The F command line utility for quick experiments. @@ -1368,3 +1600,5 @@ =cut +1 +