--- JSON-XS/XS.pm 2008/03/27 06:37:35 1.99 +++ JSON-XS/XS.pm 2008/11/20 03:59:53 1.113 @@ -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. @@ -67,7 +65,7 @@ =item * round-trip integrity -When you serialise a perl data structure using only datatypes supported +When you serialise a perl data structure using only data types 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 @@ -86,13 +84,13 @@ =item * simple to use -This module has both a simple functional interface as well as an objetc +This module has both a simple functional interface as well as an object oriented interface 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. @@ -103,9 +101,10 @@ package JSON::XS; +no warnings; use strict; -our $VERSION = '2.2'; +our $VERSION = '2.231'; our @ISA = qw(Exporter); our @EXPORT = qw(encode_json decode_json to_json from_json); @@ -139,7 +138,7 @@ $json_text = JSON::XS->new->utf8->encode ($perl_scalar) -except being faster. +Except being faster. =item $perl_scalar = decode_json $json_text @@ -151,7 +150,7 @@ $perl_scalar = JSON::XS->new->utf8->decode ($json_text) -except being faster. +Except being faster. =item $is_boolean = JSON::XS::is_bool $scalar @@ -199,7 +198,7 @@ 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. @@ -630,9 +629,9 @@ =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<[> @@ -642,9 +641,12 @@ 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. @@ -654,13 +656,12 @@ 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. @@ -701,19 +702,25 @@ =head1 INCREMENTAL PARSING -[This section and the API it details 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 parenthese +mismatches. 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 @@ -766,6 +773,15 @@ 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. +=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 ot 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 @@ -1015,7 +1031,7 @@ C<1>, which get turned into C and C atoms in JSON. You can also use C and C to improve readability. - encode_json [\0,JSON::XS::true] # yields [false,true] + encode_json [\0, JSON::XS::true] # yields [false,true] =item JSON::XS::true, JSON::XS::false @@ -1232,8 +1248,9 @@ 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, + true, false]} It shows the number of encodes/decodes per second (JSON::XS uses the functional interface, while JSON::XS/2 uses the OO interface @@ -1341,9 +1358,8 @@ =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.