… | |
… | |
101 | |
101 | |
102 | package JSON::XS; |
102 | package JSON::XS; |
103 | |
103 | |
104 | use common::sense; |
104 | use common::sense; |
105 | |
105 | |
106 | our $VERSION = '3.0'; |
106 | our $VERSION = 3.01; |
107 | our @ISA = qw(Exporter); |
107 | our @ISA = qw(Exporter); |
108 | |
108 | |
109 | our @EXPORT = qw(encode_json decode_json); |
109 | our @EXPORT = qw(encode_json decode_json); |
110 | |
110 | |
111 | use Exporter; |
111 | use Exporter; |
… | |
… | |
1144 | The C<FREEZE> method can return any number of values (i.e. zero or |
1144 | The C<FREEZE> method can return any number of values (i.e. zero or |
1145 | more). These values and the paclkage/classname of the object will then be |
1145 | more). These values and the paclkage/classname of the object will then be |
1146 | encoded as a tagged JSON value in the following format: |
1146 | encoded as a tagged JSON value in the following format: |
1147 | |
1147 | |
1148 | ("classname")[FREEZE return values...] |
1148 | ("classname")[FREEZE return values...] |
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1149 | |
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1150 | e.g.: |
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1151 | |
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1152 | ("URI")["http://www.google.com/"] |
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1153 | ("MyDate")[2013,10,29] |
|
|
1154 | ("ImageData::JPEG")["Z3...VlCg=="] |
1149 | |
1155 | |
1150 | For example, the hypothetical C<My::Object> C<FREEZE> method might use the |
1156 | For example, the hypothetical C<My::Object> C<FREEZE> method might use the |
1151 | objects C<type> and C<id> members to encode the object: |
1157 | objects C<type> and C<id> members to encode the object: |
1152 | |
1158 | |
1153 | sub My::Object::FREEZE { |
1159 | sub My::Object::FREEZE { |
… | |
… | |
1555 | constants. That means that the JSON true and false values will be |
1561 | constants. That means that the JSON true and false values will be |
1556 | comaptible to true and false values of iother modules that do the same, |
1562 | comaptible to true and false values of iother modules that do the same, |
1557 | such as L<JSON::PP> and L<CBOR::XS>. |
1563 | such as L<JSON::PP> and L<CBOR::XS>. |
1558 | |
1564 | |
1559 | |
1565 | |
|
|
1566 | =head1 INTEROPERABILITY WITH OTHER JSON DECODERS |
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1567 | |
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1568 | As long as you only serialise data that can be directly expressed in JSON, |
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1569 | C<JSON::XS> is incapable of generating invalid JSON output (modulo bugs, |
|
|
1570 | but C<JSON::XS> has found more bugs in the official JSON testsuite (1) |
|
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1571 | than the official JSON testsuite has found in C<JSON::XS> (0)). |
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1572 | |
|
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1573 | When you have trouble decoding JSON generated by this module using other |
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1574 | decoders, then it is very likely that you have an encoding mismatch or the |
|
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1575 | other decoder is broken. |
|
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1576 | |
|
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1577 | When decoding, C<JSON::XS> is strict by default and will likely catch all |
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1578 | errors. There are currently two settings that change this: C<relaxed> |
|
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1579 | makes C<JSON::XS> accept (but not generate) some non-standard extensions, |
|
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1580 | and C<allow_tags> will allow you to encode and decode Perl objects, at the |
|
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1581 | cost of not outputting valid JSON anymore. |
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1582 | |
|
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1583 | =head2 TAGGED VALUE SYNTAX AND STANDARD JSON EN/DECODERS |
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1584 | |
|
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1585 | When you use C<allow_tags> to use the extended (and also nonstandard and |
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1586 | invalid) JSON syntax for serialised objects, and you still want to decode |
|
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1587 | the generated When you want to serialise objects, you can run a regex |
|
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1588 | to replace the tagged syntax by standard JSON arrays (it only works for |
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1589 | "normal" packagesnames without comma, newlines or single colons). First, |
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1590 | the readable Perl version: |
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1591 | |
|
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1592 | # if your FREEZE methods return no values, you need this replace first: |
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1593 | $json =~ s/\( \s* (" (?: [^\\":,]+|\\.|::)* ") \s* \) \s* \[\s*\]/[$1]/gx; |
|
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1594 | |
|
|
1595 | # this works for non-empty constructor arg lists: |
|
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1596 | $json =~ s/\( \s* (" (?: [^\\":,]+|\\.|::)* ") \s* \) \s* \[/[$1,/gx; |
|
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1597 | |
|
|
1598 | And here is a less readable version that is easy to adapt to other |
|
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1599 | languages: |
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1600 | |
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1601 | $json =~ s/\(\s*("([^\\":,]+|\\.|::)*")\s*\)\s*\[/[$1,/g; |
|
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1602 | |
|
|
1603 | Here is an ECMAScript version (same regex): |
|
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1604 | |
|
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1605 | json = json.replace (/\(\s*("([^\\":,]+|\\.|::)*")\s*\)\s*\[/g, "[$1,"); |
|
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1606 | |
|
|
1607 | Since this syntax converts to standard JSON arrays, it might be hard to |
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1608 | distinguish serialised objects from normal arrays. You can prepend a |
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1609 | "magic number" as first array element to reduce chances of a collision: |
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1610 | |
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1611 | $json =~ s/\(\s*("([^\\":,]+|\\.|::)*")\s*\)\s*\[/["XU1peReLzT4ggEllLanBYq4G9VzliwKF",$1,/g; |
|
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1612 | |
|
|
1613 | And after decoding the JSON text, you could walk the data |
|
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1614 | structure looking for arrays with a first element of |
|
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1615 | C<XU1peReLzT4ggEllLanBYq4G9VzliwKF>. |
|
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1616 | |
|
|
1617 | The same approach cna be used to create the tagged format with another |
|
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1618 | encoder. First, you create an array with the magic string as first member, |
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1619 | the classname as second, and constructor arguments last, encode it as part |
|
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1620 | of your JSON structure, and then: |
|
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1621 | |
|
|
1622 | $json =~ s/\[\s*"XU1peReLzT4ggEllLanBYq4G9VzliwKF"\s*,\s*("([^\\":,]+|\\.|::)*")\s*,/($1)[/g; |
|
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1623 | |
|
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1624 | Again, this has some limitations - the magic string must not be encoded |
|
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1625 | with character escapes, and the constructor arguments must be non-empty. |
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1626 | |
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1627 | |
|
|
1628 | =head1 RFC7158 |
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1629 | |
|
|
1630 | Since this module was written, Google has written a new JSON RFC, RFC |
|
|
1631 | 7158. Unfortunately, this RFC breaks compatibility with both the original |
|
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1632 | JSON specification on www.json.org and RFC4627. |
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1633 | |
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1634 | As far as I can see, you can get partial compatibility when parsing by |
|
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1635 | using C<< ->allow_nonref >>. However, consider thew security implications |
|
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1636 | of doing so. |
|
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1637 | |
|
|
1638 | I haven't decided yet whether to break compatibility with RFC4627 by |
|
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1639 | default (and potentially leave applications insecure), or change the |
|
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1640 | default to follow RFC7158. |
|
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1641 | |
|
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1642 | |
1560 | =head1 THREADS |
1643 | =head1 THREADS |
1561 | |
1644 | |
1562 | This module is I<not> guaranteed to be thread safe and there are no |
1645 | This module is I<not> guaranteed to be thread safe and there are no |
1563 | plans to change this until Perl gets thread support (as opposed to the |
1646 | plans to change this until Perl gets thread support (as opposed to the |
1564 | horribly slow so-called "threads" which are simply slow and bloated |
1647 | horribly slow so-called "threads" which are simply slow and bloated |