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

Comparing JSON-XS/XS.pm (file contents):
Revision 1.124 by root, Sun Aug 9 16:01:39 2009 UTC vs.
Revision 1.139 by root, Thu May 23 09:31:32 2013 UTC

 so, and even documents what "correct" means.
 =item * round-trip integrity
 When you serialise a perl data structure using only data types supported
-by JSON, the deserialised data structure is identical on the Perl level.
+by JSON and Perl, the deserialised data structure is identical on the Perl
-(e.g. the string "2.0" doesn't suddenly become "2" just because it looks
+level. (e.g. the string "2.0" doesn't suddenly become "2" just because
-like a number). There minor I<are> exceptions to this, read the MAPPING
+it looks like a number). There I<are> minor exceptions to this, read the
-section below to learn about those.
+MAPPING section below to learn about those.
 =item * strict checking of JSON correctness
 There is no guessing, no generating of illegal JSON texts by default,
 and only JSON is accepted as input by default (the latter is a security
 package JSON::XS;
 use common::sense;
-our $VERSION = '2.25';
+our $VERSION = 2.34;
 our @ISA = qw(Exporter);
 our @EXPORT = qw(encode_json decode_json to_json from_json);
 sub to_json($) {
 If C<$enable> is true (or missing), then the C<encode> method will output JSON objects
 by sorting their keys. This is adding a comparatively high overhead.
 If C<$enable> is false, then the C<encode> 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,
 the same hash might be encoded differently even if contains the same data,
 as key-value pairs have no inherent ordering in Perl.
 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
+early as the full parser, for example, it doesn't detect mismatched
-mismatches. The only thing it guarantees is that it starts decoding as
+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<max_size>) to ensure the parser will stop
 parsing in the presence if syntax errors.
 The following methods implement this incremental parser.
 otherwise. For this to work, there must be no separators between the JSON
 objects or arrays, instead they must be concatenated back-to-back. If
 an error occurs, an exception will be raised as in the scalar context
 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
 is, you can manipulate it. This I<only> works when a preceding call to
 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 leats significant bit.
 =item true, false
 These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>,
 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
 You can not currently force the type in other, less obscure, ways. Tell me
 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
 =head1 ENCODING/CODESET FLAG NOTES
 well - using C<eval> naively simply I<will> 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 it's own purposes.
+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;
 that difficult or long) and finally make YAML compatible to it, and
 educating users about the changes, instead of spreading lies about the
 real compatibility for many I<years> and trying to silence people who
 point out that it isn't true.
-Addendum/2009: the YAML 1.2 spec is still incomaptible with JSON, even
+Addendum/2009: the YAML 1.2 spec is still incompatible with JSON, even
-though the incompatibilities have been documented (and are known to
+though the incompatibilities have been documented (and are known to Brian)
-Brian) for many years and the spec makes explicit claims that YAML is a
+for many years and the spec makes explicit claims that YAML is a superset
-superset of JSON. It would be so easy to fix, but apparently, bullying and
+of JSON. It would be so easy to fix, but apparently, bullying people and
 corrupting userdata is so much easier.
 =back
 a very short single-line JSON string (also available at
 L<http://dist.schmorp.de/misc/json/short.json>).
    {"method": "handleMessage", "params": ["user1",
    "we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7,
-   true,  false]}
+   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 |
+   module        |     encode |     decode |
-   -----------|------------|------------|
+   --------------|------------|------------|
-   JSON 1.x   |   4990.842 |   4088.813 |
+   JSON::DWIW/DS |  86302.551 | 102300.098 |
-   JSON::DWIW |  51653.990 |  71575.154 |
+   JSON::DWIW/FJ |  86302.551 |  75983.768 |
-   JSON::PC   |  65948.176 |  74631.744 |
+   JSON::PP      |  15827.562 |   6638.658 |
-   JSON::PP   |   8931.652 |   3817.168 |
+   JSON::Syck    |  63358.066 |  47662.545 |
-   JSON::Syck |  24877.248 |  27776.848 |
+   JSON::XS      | 511500.488 | 511500.488 |
-   JSON::XS   | 388361.481 | 227951.304 |
+   JSON::XS/2    | 291271.111 | 388361.481 |
-   JSON::XS/2 | 227951.304 | 218453.333 |
+   JSON::XS/3    | 361577.931 | 361577.931 |
-   JSON::XS/3 | 338250.323 | 218453.333 |
+   Storable      |  66788.280 | 265462.278 |
-   Storable   |  16500.016 | 135300.129 |
-   -----------+------------+------------+
+   --------------+------------+------------+
-That is, JSON::XS is about five times faster than JSON::DWIW on encoding,
+That is, JSON::XS is almost six times faster than JSON::DWIW on encoding,
-about three times faster on decoding, and over forty times faster
+about five times faster on decoding, and over thirty to seventy times
-than JSON, even with pretty-printing and key sorting. It also compares
+faster than JSON's pure perl implementation. It also compares favourably
-favourably to Storable for small amounts of data.
+to Storable for small amounts of data.
 Using a longer test string (roughly 18KB, generated from Yahoo! Locals
 search API (L<http://dist.schmorp.de/misc/json/long.json>).
-   module     |     encode |     decode |
+   module        |     encode |     decode |
-   -----------|------------|------------|
+   --------------|------------|------------|
-   JSON 1.x   |     55.260 |     34.971 |
+   JSON::DWIW/DS |   1647.927 |   2673.916 |
-   JSON::DWIW |    825.228 |   1082.513 |
+   JSON::DWIW/FJ |   1630.249 |   2596.128 |
-   JSON::PC   |   3571.444 |   2394.829 |
-   JSON::PP   |    210.987 |     32.574 |
+   JSON::PP      |    400.640 |     62.311 |
-   JSON::Syck |    552.551 |    787.544 |
+   JSON::Syck    |   1481.040 |   1524.869 |
-   JSON::XS   |   5780.463 |   4854.519 |
+   JSON::XS      |  20661.596 |   9541.183 |
-   JSON::XS/2 |   3869.998 |   4798.975 |
+   JSON::XS/2    |  10683.403 |   9416.938 |
-   JSON::XS/3 |   5862.880 |   4798.975 |
+   JSON::XS/3    |  20661.596 |   9400.054 |
-   Storable   |   4445.002 |   5235.027 |
+   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
 will be broken due to missing (or wrong) Unicode handling. Others refuse
 to decode or encode properly, so it was impossible to prepare a fair
 information you might want to make sure that exceptions thrown by JSON::XS
 will not end up in front of untrusted eyes.
 If you are using JSON::XS to return packets to consumption
 by JavaScript scripts in a browser you should have a look at
-L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether
+L<http://blog.archive.jpsykes.com/47/practical-csrf-and-json-security/> to
-you are vulnerable to some common attack vectors (which really are browser
+see whether you are vulnerable to some common attack vectors (which really
-design bugs, but it is still you who will have to deal with it, as major
+are browser design bugs, but it is still you who will have to deal with
-browser developers care only for features, not about getting security
+it, as major browser developers care only for features, not about getting
-right).
+security right).
 =head1 THREADS
 This module is I<not> guaranteed to be thread safe and there are no
 plans to change this until Perl gets thread support (as opposed to the
 horribly slow so-called "threads" which are simply slow and bloated
 process simulations - use fork, it's I<much> faster, cheaper, better).
 (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<LC_ALL>.
+This breaks both perl and modules such as JSON::XS, as stringification of
+numbers no longer works correcly (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<setlocale>, or use it for only those
+categories you need, such as C<LC_MESSAGES> or C<LC_CTYPE>.
+If you need C<LC_NUMERIC>, 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

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Comparing JSON-XS/XS.pm (file contents): Revision 1.124 by root, Sun Aug 9 16:01:39 2009 UTC vs. Revision 1.139 by root, Thu May 23 09:31:32 2013 UTC

Diff Legend

Comparing JSON-XS/XS.pm (file contents):
Revision 1.124 by root, Sun Aug 9 16:01:39 2009 UTC vs.
Revision 1.139 by root, Thu May 23 09:31:32 2013 UTC