1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | JSON::XS - JSON serialising/deserialising, done correctly and fast |
3 | JSON::XS - JSON serialising/deserialising, done correctly and fast |
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4 | |
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5 | =encoding utf-8 |
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 |
6 | (http://fleur.hio.jp/perldoc/mix/lib/JSON/XS.html) |
8 | (http://fleur.hio.jp/perldoc/mix/lib/JSON/XS.html) |
7 | |
9 | |
8 | =head1 SYNOPSIS |
10 | =head1 SYNOPSIS |
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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); |
22 | $perl_scalar = $coder->decode ($unicode_json_text); |
24 | $perl_scalar = $coder->decode ($unicode_json_text); |
23 | |
25 | |
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26 | # Note that JSON version 2.0 and above will automatically use JSON::XS |
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27 | # if available, at virtually no speed overhead either, so you should |
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28 | # be able to just: |
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29 | |
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30 | use JSON; |
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31 | |
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32 | # and do the same things, except that you have a pure-perl fallback now. |
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33 | |
24 | =head1 DESCRIPTION |
34 | =head1 DESCRIPTION |
25 | |
35 | |
26 | This module converts Perl data structures to JSON and vice versa. Its |
36 | This module converts Perl data structures to JSON and vice versa. Its |
27 | primary goal is to be I<correct> and its secondary goal is to be |
37 | primary goal is to be I<correct> and its secondary goal is to be |
28 | I<fast>. To reach the latter goal it was written in C. |
38 | I<fast>. To reach the latter goal it was written in C. |
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39 | |
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40 | Beginning with version 2.0 of the JSON module, when both JSON and |
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41 | JSON::XS are installed, then JSON will fall back on JSON::XS (this can be |
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42 | overridden) with no overhead due to emulation (by inheriting constructor |
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43 | and methods). If JSON::XS is not available, it will fall back to the |
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44 | compatible JSON::PP module as backend, so using JSON instead of JSON::XS |
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45 | gives you a portable JSON API that can be fast when you need and doesn't |
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46 | require a C compiler when that is a problem. |
29 | |
47 | |
30 | As this is the n-th-something JSON module on CPAN, what was the reason |
48 | As this is the n-th-something JSON module on CPAN, what was the reason |
31 | to write yet another JSON module? While it seems there are many JSON |
49 | to write yet another JSON module? While it seems there are many JSON |
32 | modules, none of them correctly handle all corner cases, and in most cases |
50 | modules, none of them correctly handle all corner cases, and in most cases |
33 | their maintainers are unresponsive, gone missing, or not listening to bug |
51 | their maintainers are unresponsive, gone missing, or not listening to bug |
… | |
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42 | |
60 | |
43 | =over 4 |
61 | =over 4 |
44 | |
62 | |
45 | =item * correct Unicode handling |
63 | =item * correct Unicode handling |
46 | |
64 | |
47 | 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 |
48 | it does so. |
66 | so, and even documents what "correct" means. |
49 | |
67 | |
50 | =item * round-trip integrity |
68 | =item * round-trip integrity |
51 | |
69 | |
52 | When you serialise a perl data structure using only datatypes supported |
70 | When you serialise a perl data structure using only data types supported |
53 | 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. |
54 | (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 |
55 | like a number). |
73 | like a number). There minor I<are> exceptions to this, read the MAPPING |
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74 | section below to learn about those. |
56 | |
75 | |
57 | =item * strict checking of JSON correctness |
76 | =item * strict checking of JSON correctness |
58 | |
77 | |
59 | 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, |
60 | 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 |
61 | feature). |
80 | feature). |
62 | |
81 | |
63 | =item * fast |
82 | =item * fast |
64 | |
83 | |
65 | Compared to other JSON modules, this module compares favourably in terms |
84 | Compared to other JSON modules and other serialisers such as Storable, |
66 | of speed, too. |
85 | this module usually compares favourably in terms of speed, too. |
67 | |
86 | |
68 | =item * simple to use |
87 | =item * simple to use |
69 | |
88 | |
70 | 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 object |
71 | interface. |
90 | oriented interface interface. |
72 | |
91 | |
73 | =item * reasonably versatile output formats |
92 | =item * reasonably versatile output formats |
74 | |
93 | |
75 | You can choose between the most compact guaranteed single-line format |
94 | You can choose between the most compact guaranteed-single-line format |
76 | possible (nice for simple line-based protocols), a pure-ascii format |
95 | possible (nice for simple line-based protocols), a pure-ASCII format |
77 | (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 |
78 | 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 |
79 | 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. |
80 | |
99 | |
81 | =back |
100 | =back |
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84 | |
103 | |
85 | package JSON::XS; |
104 | package JSON::XS; |
86 | |
105 | |
87 | use strict; |
106 | use strict; |
88 | |
107 | |
89 | our $VERSION = '1.52'; |
108 | our $VERSION = '2.2'; |
90 | our @ISA = qw(Exporter); |
109 | our @ISA = qw(Exporter); |
91 | |
110 | |
92 | our @EXPORT = qw(to_json from_json); |
111 | our @EXPORT = qw(encode_json decode_json to_json from_json); |
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112 | |
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113 | sub to_json($) { |
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114 | require Carp; |
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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"); |
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116 | } |
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117 | |
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118 | sub from_json($) { |
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119 | require Carp; |
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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"); |
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121 | } |
93 | |
122 | |
94 | use Exporter; |
123 | use Exporter; |
95 | use XSLoader; |
124 | use XSLoader; |
96 | |
125 | |
97 | =head1 FUNCTIONAL INTERFACE |
126 | =head1 FUNCTIONAL INTERFACE |
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99 | The following convenience methods are provided by this module. They are |
128 | The following convenience methods are provided by this module. They are |
100 | exported by default: |
129 | exported by default: |
101 | |
130 | |
102 | =over 4 |
131 | =over 4 |
103 | |
132 | |
104 | =item $json_text = to_json $perl_scalar |
133 | =item $json_text = encode_json $perl_scalar |
105 | |
134 | |
106 | 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 |
107 | (that is, the string contains octets only). Croaks on error. |
136 | (that is, the string contains octets only). Croaks on error. |
108 | |
137 | |
109 | This function call is functionally identical to: |
138 | This function call is functionally identical to: |
110 | |
139 | |
111 | $json_text = JSON::XS->new->utf8->encode ($perl_scalar) |
140 | $json_text = JSON::XS->new->utf8->encode ($perl_scalar) |
112 | |
141 | |
113 | except being faster. |
142 | Except being faster. |
114 | |
143 | |
115 | =item $perl_scalar = from_json $json_text |
144 | =item $perl_scalar = decode_json $json_text |
116 | |
145 | |
117 | 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 |
118 | 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 |
119 | reference. Croaks on error. |
148 | reference. Croaks on error. |
120 | |
149 | |
121 | This function call is functionally identical to: |
150 | This function call is functionally identical to: |
122 | |
151 | |
123 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
152 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
124 | |
153 | |
125 | except being faster. |
154 | Except being faster. |
126 | |
155 | |
127 | =item $is_boolean = JSON::XS::is_bool $scalar |
156 | =item $is_boolean = JSON::XS::is_bool $scalar |
128 | |
157 | |
129 | Returns true if the passed scalar represents either JSON::XS::true or |
158 | Returns true if the passed scalar represents either JSON::XS::true or |
130 | JSON::XS::false, two constants that act like C<1> and C<0>, respectively |
159 | JSON::XS::false, two constants that act like C<1> and C<0>, respectively |
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148 | 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 |
149 | Perl string - very natural. |
178 | Perl string - very natural. |
150 | |
179 | |
151 | =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. |
152 | |
181 | |
153 | 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 |
154 | 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 |
155 | locale-encoded text, octets/binary, or as Unicode, depending on various |
184 | string as locale-encoded text, octets/binary, or as Unicode, depending |
156 | 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 |
157 | I<use> that decides encoding, not any magical metadata. |
186 | data, it is I<use> that decides encoding, not any magical meta data. |
158 | |
187 | |
159 | =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 |
160 | encoding of your string. |
189 | encoding of your string. |
161 | |
190 | |
162 | 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 |
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168 | |
197 | |
169 | If you didn't know about that flag, just the better, pretend it doesn't |
198 | If you didn't know about that flag, just the better, pretend it doesn't |
170 | exist. |
199 | exist. |
171 | |
200 | |
172 | =item 4. A "Unicode String" is simply a string where each character can be |
201 | =item 4. A "Unicode String" is simply a string where each character can be |
173 | validly interpreted as a Unicode codepoint. |
202 | validly interpreted as a Unicode code point. |
174 | |
203 | |
175 | If you have UTF-8 encoded data, it is no longer a Unicode string, but a |
204 | If you have UTF-8 encoded data, it is no longer a Unicode string, but a |
176 | Unicode string encoded in UTF-8, giving you a binary string. |
205 | Unicode string encoded in UTF-8, giving you a binary string. |
177 | |
206 | |
178 | =item 5. A string containing "high" (> 255) character values is I<not> a UTF-8 string. |
207 | =item 5. A string containing "high" (> 255) character values is I<not> a UTF-8 string. |
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201 | |
230 | |
202 | my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]}) |
231 | my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]}) |
203 | => {"a": [1, 2]} |
232 | => {"a": [1, 2]} |
204 | |
233 | |
205 | =item $json = $json->ascii ([$enable]) |
234 | =item $json = $json->ascii ([$enable]) |
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235 | |
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236 | =item $enabled = $json->get_ascii |
206 | |
237 | |
207 | If C<$enable> is true (or missing), then the C<encode> method will not |
238 | If C<$enable> is true (or missing), then the C<encode> method will not |
208 | generate characters outside the code range C<0..127> (which is ASCII). Any |
239 | generate characters outside the code range C<0..127> (which is ASCII). Any |
209 | Unicode characters outside that range will be escaped using either a |
240 | Unicode characters outside that range will be escaped using either a |
210 | single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, |
241 | single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, |
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214 | |
245 | |
215 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
246 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
216 | characters unless required by the JSON syntax or other flags. This results |
247 | characters unless required by the JSON syntax or other flags. This results |
217 | in a faster and more compact format. |
248 | in a faster and more compact format. |
218 | |
249 | |
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250 | See also the section I<ENCODING/CODESET FLAG NOTES> later in this |
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251 | document. |
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252 | |
219 | The main use for this flag is to produce JSON texts that can be |
253 | The main use for this flag is to produce JSON texts that can be |
220 | transmitted over a 7-bit channel, as the encoded JSON texts will not |
254 | transmitted over a 7-bit channel, as the encoded JSON texts will not |
221 | contain any 8 bit characters. |
255 | contain any 8 bit characters. |
222 | |
256 | |
223 | JSON::XS->new->ascii (1)->encode ([chr 0x10401]) |
257 | JSON::XS->new->ascii (1)->encode ([chr 0x10401]) |
224 | => ["\ud801\udc01"] |
258 | => ["\ud801\udc01"] |
225 | |
259 | |
226 | =item $json = $json->latin1 ([$enable]) |
260 | =item $json = $json->latin1 ([$enable]) |
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261 | |
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262 | =item $enabled = $json->get_latin1 |
227 | |
263 | |
228 | If C<$enable> is true (or missing), then the C<encode> method will encode |
264 | If C<$enable> is true (or missing), then the C<encode> method will encode |
229 | the resulting JSON text as latin1 (or iso-8859-1), escaping any characters |
265 | the resulting JSON text as latin1 (or iso-8859-1), escaping any characters |
230 | outside the code range C<0..255>. The resulting string can be treated as a |
266 | outside the code range C<0..255>. The resulting string can be treated as a |
231 | latin1-encoded JSON text or a native Unicode string. The C<decode> method |
267 | latin1-encoded JSON text or a native Unicode string. The C<decode> method |
232 | will not be affected in any way by this flag, as C<decode> by default |
268 | will not be affected in any way by this flag, as C<decode> by default |
233 | expects Unicode, which is a strict superset of latin1. |
269 | expects Unicode, which is a strict superset of latin1. |
234 | |
270 | |
235 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
271 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
236 | characters unless required by the JSON syntax or other flags. |
272 | characters unless required by the JSON syntax or other flags. |
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273 | |
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274 | See also the section I<ENCODING/CODESET FLAG NOTES> later in this |
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275 | document. |
237 | |
276 | |
238 | The main use for this flag is efficiently encoding binary data as JSON |
277 | The main use for this flag is efficiently encoding binary data as JSON |
239 | text, as most octets will not be escaped, resulting in a smaller encoded |
278 | text, as most octets will not be escaped, resulting in a smaller encoded |
240 | size. The disadvantage is that the resulting JSON text is encoded |
279 | size. The disadvantage is that the resulting JSON text is encoded |
241 | in latin1 (and must correctly be treated as such when storing and |
280 | in latin1 (and must correctly be treated as such when storing and |
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246 | JSON::XS->new->latin1->encode (["\x{89}\x{abc}"] |
285 | JSON::XS->new->latin1->encode (["\x{89}\x{abc}"] |
247 | => ["\x{89}\\u0abc"] # (perl syntax, U+abc escaped, U+89 not) |
286 | => ["\x{89}\\u0abc"] # (perl syntax, U+abc escaped, U+89 not) |
248 | |
287 | |
249 | =item $json = $json->utf8 ([$enable]) |
288 | =item $json = $json->utf8 ([$enable]) |
250 | |
289 | |
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290 | =item $enabled = $json->get_utf8 |
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291 | |
251 | If C<$enable> is true (or missing), then the C<encode> method will encode |
292 | If C<$enable> is true (or missing), then the C<encode> method will encode |
252 | the JSON result into UTF-8, as required by many protocols, while the |
293 | the JSON result into UTF-8, as required by many protocols, while the |
253 | C<decode> method expects to be handled an UTF-8-encoded string. Please |
294 | C<decode> method expects to be handled an UTF-8-encoded string. Please |
254 | note that UTF-8-encoded strings do not contain any characters outside the |
295 | note that UTF-8-encoded strings do not contain any characters outside the |
255 | range C<0..255>, they are thus useful for bytewise/binary I/O. In future |
296 | range C<0..255>, they are thus useful for bytewise/binary I/O. In future |
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258 | |
299 | |
259 | If C<$enable> is false, then the C<encode> method will return the JSON |
300 | If C<$enable> is false, then the C<encode> method will return the JSON |
260 | string as a (non-encoded) Unicode string, while C<decode> expects thus a |
301 | string as a (non-encoded) Unicode string, while C<decode> expects thus a |
261 | Unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs |
302 | Unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs |
262 | to be done yourself, e.g. using the Encode module. |
303 | to be done yourself, e.g. using the Encode module. |
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304 | |
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305 | See also the section I<ENCODING/CODESET FLAG NOTES> later in this |
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306 | document. |
263 | |
307 | |
264 | Example, output UTF-16BE-encoded JSON: |
308 | Example, output UTF-16BE-encoded JSON: |
265 | |
309 | |
266 | use Encode; |
310 | use Encode; |
267 | $jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object); |
311 | $jsontext = encode "UTF-16BE", JSON::XS->new->encode ($object); |
… | |
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288 | ] |
332 | ] |
289 | } |
333 | } |
290 | |
334 | |
291 | =item $json = $json->indent ([$enable]) |
335 | =item $json = $json->indent ([$enable]) |
292 | |
336 | |
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337 | =item $enabled = $json->get_indent |
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338 | |
293 | If C<$enable> is true (or missing), then the C<encode> method will use a multiline |
339 | If C<$enable> is true (or missing), then the C<encode> method will use a multiline |
294 | format as output, putting every array member or object/hash key-value pair |
340 | format as output, putting every array member or object/hash key-value pair |
295 | into its own line, indenting them properly. |
341 | into its own line, indenting them properly. |
296 | |
342 | |
297 | If C<$enable> is false, no newlines or indenting will be produced, and the |
343 | If C<$enable> is false, no newlines or indenting will be produced, and the |
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299 | |
345 | |
300 | This setting has no effect when decoding JSON texts. |
346 | This setting has no effect when decoding JSON texts. |
301 | |
347 | |
302 | =item $json = $json->space_before ([$enable]) |
348 | =item $json = $json->space_before ([$enable]) |
303 | |
349 | |
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350 | =item $enabled = $json->get_space_before |
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351 | |
304 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
352 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
305 | optional space before the C<:> separating keys from values in JSON objects. |
353 | optional space before the C<:> separating keys from values in JSON objects. |
306 | |
354 | |
307 | If C<$enable> is false, then the C<encode> method will not add any extra |
355 | If C<$enable> is false, then the C<encode> method will not add any extra |
308 | space at those places. |
356 | space at those places. |
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313 | Example, space_before enabled, space_after and indent disabled: |
361 | Example, space_before enabled, space_after and indent disabled: |
314 | |
362 | |
315 | {"key" :"value"} |
363 | {"key" :"value"} |
316 | |
364 | |
317 | =item $json = $json->space_after ([$enable]) |
365 | =item $json = $json->space_after ([$enable]) |
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366 | |
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367 | =item $enabled = $json->get_space_after |
318 | |
368 | |
319 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
369 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
320 | optional space after the C<:> separating keys from values in JSON objects |
370 | optional space after the C<:> separating keys from values in JSON objects |
321 | and extra whitespace after the C<,> separating key-value pairs and array |
371 | and extra whitespace after the C<,> separating key-value pairs and array |
322 | members. |
372 | members. |
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329 | Example, space_before and indent disabled, space_after enabled: |
379 | Example, space_before and indent disabled, space_after enabled: |
330 | |
380 | |
331 | {"key": "value"} |
381 | {"key": "value"} |
332 | |
382 | |
333 | =item $json = $json->relaxed ([$enable]) |
383 | =item $json = $json->relaxed ([$enable]) |
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384 | |
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385 | =item $enabled = $json->get_relaxed |
334 | |
386 | |
335 | If C<$enable> is true (or missing), then C<decode> will accept some |
387 | If C<$enable> is true (or missing), then C<decode> will accept some |
336 | extensions to normal JSON syntax (see below). C<encode> will not be |
388 | extensions to normal JSON syntax (see below). C<encode> will not be |
337 | affected in anyway. I<Be aware that this option makes you accept invalid |
389 | affected in anyway. I<Be aware that this option makes you accept invalid |
338 | JSON texts as if they were valid!>. I suggest only to use this option to |
390 | JSON texts as if they were valid!>. I suggest only to use this option to |
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375 | |
427 | |
376 | =back |
428 | =back |
377 | |
429 | |
378 | =item $json = $json->canonical ([$enable]) |
430 | =item $json = $json->canonical ([$enable]) |
379 | |
431 | |
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432 | =item $enabled = $json->get_canonical |
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433 | |
380 | If C<$enable> is true (or missing), then the C<encode> method will output JSON objects |
434 | If C<$enable> is true (or missing), then the C<encode> method will output JSON objects |
381 | by sorting their keys. This is adding a comparatively high overhead. |
435 | by sorting their keys. This is adding a comparatively high overhead. |
382 | |
436 | |
383 | If C<$enable> is false, then the C<encode> method will output key-value |
437 | If C<$enable> is false, then the C<encode> method will output key-value |
384 | pairs in the order Perl stores them (which will likely change between runs |
438 | pairs in the order Perl stores them (which will likely change between runs |
… | |
… | |
391 | |
445 | |
392 | This setting has no effect when decoding JSON texts. |
446 | This setting has no effect when decoding JSON texts. |
393 | |
447 | |
394 | =item $json = $json->allow_nonref ([$enable]) |
448 | =item $json = $json->allow_nonref ([$enable]) |
395 | |
449 | |
|
|
450 | =item $enabled = $json->get_allow_nonref |
|
|
451 | |
396 | If C<$enable> is true (or missing), then the C<encode> method can convert a |
452 | If C<$enable> is true (or missing), then the C<encode> method can convert a |
397 | non-reference into its corresponding string, number or null JSON value, |
453 | non-reference into its corresponding string, number or null JSON value, |
398 | which is an extension to RFC4627. Likewise, C<decode> will accept those JSON |
454 | which is an extension to RFC4627. Likewise, C<decode> will accept those JSON |
399 | values instead of croaking. |
455 | values instead of croaking. |
400 | |
456 | |
… | |
… | |
407 | resulting in an invalid JSON text: |
463 | resulting in an invalid JSON text: |
408 | |
464 | |
409 | JSON::XS->new->allow_nonref->encode ("Hello, World!") |
465 | JSON::XS->new->allow_nonref->encode ("Hello, World!") |
410 | => "Hello, World!" |
466 | => "Hello, World!" |
411 | |
467 | |
|
|
468 | =item $json = $json->allow_unknown ([$enable]) |
|
|
469 | |
|
|
470 | =item $enabled = $json->get_allow_unknown |
|
|
471 | |
|
|
472 | If C<$enable> is true (or missing), then C<encode> will I<not> throw an |
|
|
473 | exception when it encounters values it cannot represent in JSON (for |
|
|
474 | example, filehandles) but instead will encode a JSON C<null> value. Note |
|
|
475 | that blessed objects are not included here and are handled separately by |
|
|
476 | c<allow_nonref>. |
|
|
477 | |
|
|
478 | If C<$enable> is false (the default), then C<encode> will throw an |
|
|
479 | exception when it encounters anything it cannot encode as JSON. |
|
|
480 | |
|
|
481 | This option does not affect C<decode> in any way, and it is recommended to |
|
|
482 | leave it off unless you know your communications partner. |
|
|
483 | |
412 | =item $json = $json->allow_blessed ([$enable]) |
484 | =item $json = $json->allow_blessed ([$enable]) |
|
|
485 | |
|
|
486 | =item $enabled = $json->get_allow_blessed |
413 | |
487 | |
414 | If C<$enable> is true (or missing), then the C<encode> method will not |
488 | If C<$enable> is true (or missing), then the C<encode> method will not |
415 | barf when it encounters a blessed reference. Instead, the value of the |
489 | barf when it encounters a blessed reference. Instead, the value of the |
416 | B<convert_blessed> option will decide whether C<null> (C<convert_blessed> |
490 | B<convert_blessed> option will decide whether C<null> (C<convert_blessed> |
417 | disabled or no C<to_json> method found) or a representation of the |
491 | disabled or no C<TO_JSON> method found) or a representation of the |
418 | object (C<convert_blessed> enabled and C<to_json> method found) is being |
492 | object (C<convert_blessed> enabled and C<TO_JSON> method found) is being |
419 | encoded. Has no effect on C<decode>. |
493 | encoded. Has no effect on C<decode>. |
420 | |
494 | |
421 | If C<$enable> is false (the default), then C<encode> will throw an |
495 | If C<$enable> is false (the default), then C<encode> will throw an |
422 | exception when it encounters a blessed object. |
496 | exception when it encounters a blessed object. |
423 | |
497 | |
424 | =item $json = $json->convert_blessed ([$enable]) |
498 | =item $json = $json->convert_blessed ([$enable]) |
|
|
499 | |
|
|
500 | =item $enabled = $json->get_convert_blessed |
425 | |
501 | |
426 | If C<$enable> is true (or missing), then C<encode>, upon encountering a |
502 | If C<$enable> is true (or missing), then C<encode>, upon encountering a |
427 | blessed object, will check for the availability of the C<TO_JSON> method |
503 | blessed object, will check for the availability of the C<TO_JSON> method |
428 | on the object's class. If found, it will be called in scalar context |
504 | on the object's class. If found, it will be called in scalar context |
429 | and the resulting scalar will be encoded instead of the object. If no |
505 | and the resulting scalar will be encoded instead of the object. If no |
… | |
… | |
433 | The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON> |
509 | The C<TO_JSON> method may safely call die if it wants. If C<TO_JSON> |
434 | returns other blessed objects, those will be handled in the same |
510 | returns other blessed objects, those will be handled in the same |
435 | way. C<TO_JSON> must take care of not causing an endless recursion cycle |
511 | way. C<TO_JSON> must take care of not causing an endless recursion cycle |
436 | (== crash) in this case. The name of C<TO_JSON> was chosen because other |
512 | (== crash) in this case. The name of C<TO_JSON> was chosen because other |
437 | methods called by the Perl core (== not by the user of the object) are |
513 | methods called by the Perl core (== not by the user of the object) are |
438 | usually in upper case letters and to avoid collisions with the C<to_json> |
514 | usually in upper case letters and to avoid collisions with any C<to_json> |
439 | function. |
515 | function or method. |
440 | |
516 | |
441 | This setting does not yet influence C<decode> in any way, but in the |
517 | This setting does not yet influence C<decode> in any way, but in the |
442 | future, global hooks might get installed that influence C<decode> and are |
518 | future, global hooks might get installed that influence C<decode> and are |
443 | enabled by this setting. |
519 | enabled by this setting. |
444 | |
520 | |
… | |
… | |
520 | |
596 | |
521 | { __widget__ => $self->{id} } |
597 | { __widget__ => $self->{id} } |
522 | } |
598 | } |
523 | |
599 | |
524 | =item $json = $json->shrink ([$enable]) |
600 | =item $json = $json->shrink ([$enable]) |
|
|
601 | |
|
|
602 | =item $enabled = $json->get_shrink |
525 | |
603 | |
526 | Perl usually over-allocates memory a bit when allocating space for |
604 | Perl usually over-allocates memory a bit when allocating space for |
527 | strings. This flag optionally resizes strings generated by either |
605 | strings. This flag optionally resizes strings generated by either |
528 | C<encode> or C<decode> to their minimum size possible. This can save |
606 | C<encode> or C<decode> to their minimum size possible. This can save |
529 | memory when your JSON texts are either very very long or you have many |
607 | memory when your JSON texts are either very very long or you have many |
… | |
… | |
547 | strings that look like integers or floats into integers or floats |
625 | strings that look like integers or floats into integers or floats |
548 | internally (there is no difference on the Perl level), saving space. |
626 | internally (there is no difference on the Perl level), saving space. |
549 | |
627 | |
550 | =item $json = $json->max_depth ([$maximum_nesting_depth]) |
628 | =item $json = $json->max_depth ([$maximum_nesting_depth]) |
551 | |
629 | |
|
|
630 | =item $max_depth = $json->get_max_depth |
|
|
631 | |
552 | Sets the maximum nesting level (default C<512>) accepted while encoding |
632 | Sets the maximum nesting level (default C<512>) accepted while encoding |
553 | or decoding. If the JSON text or Perl data structure has an equal or |
633 | or decoding. If a higher nesting level is detected in JSON text or a Perl |
554 | higher nesting level then this limit, then the encoder and decoder will |
634 | data structure, then the encoder and decoder will stop and croak at that |
555 | stop and croak at that point. |
635 | point. |
556 | |
636 | |
557 | Nesting level is defined by number of hash- or arrayrefs that the encoder |
637 | Nesting level is defined by number of hash- or arrayrefs that the encoder |
558 | needs to traverse to reach a given point or the number of C<{> or C<[> |
638 | needs to traverse to reach a given point or the number of C<{> or C<[> |
559 | characters without their matching closing parenthesis crossed to reach a |
639 | characters without their matching closing parenthesis crossed to reach a |
560 | given character in a string. |
640 | given character in a string. |
561 | |
641 | |
562 | Setting the maximum depth to one disallows any nesting, so that ensures |
642 | Setting the maximum depth to one disallows any nesting, so that ensures |
563 | that the object is only a single hash/object or array. |
643 | that the object is only a single hash/object or array. |
564 | |
644 | |
565 | The argument to C<max_depth> will be rounded up to the next highest power |
|
|
566 | of two. If no argument is given, the highest possible setting will be |
645 | If no argument is given, the highest possible setting will be used, which |
567 | used, which is rarely useful. |
646 | is rarely useful. |
|
|
647 | |
|
|
648 | Note that nesting is implemented by recursion in C. The default value has |
|
|
649 | been chosen to be as large as typical operating systems allow without |
|
|
650 | crashing. |
568 | |
651 | |
569 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
652 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
570 | |
653 | |
571 | =item $json = $json->max_size ([$maximum_string_size]) |
654 | =item $json = $json->max_size ([$maximum_string_size]) |
|
|
655 | |
|
|
656 | =item $max_size = $json->get_max_size |
572 | |
657 | |
573 | Set the maximum length a JSON text may have (in bytes) where decoding is |
658 | Set the maximum length a JSON text may have (in bytes) where decoding is |
574 | being attempted. The default is C<0>, meaning no limit. When C<decode> |
659 | being attempted. The default is C<0>, meaning no limit. When C<decode> |
575 | is called on a string longer then this number of characters it will not |
660 | is called on a string that is longer then this many bytes, it will not |
576 | attempt to decode the string but throw an exception. This setting has no |
661 | attempt to decode the string but throw an exception. This setting has no |
577 | effect on C<encode> (yet). |
662 | effect on C<encode> (yet). |
578 | |
663 | |
579 | The argument to C<max_size> will be rounded up to the next B<highest> |
664 | If no argument is given, the limit check will be deactivated (same as when |
580 | power of two (so may be more than requested). If no argument is given, the |
665 | C<0> is specified). |
581 | limit check will be deactivated (same as when C<0> is specified). |
|
|
582 | |
666 | |
583 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
667 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
584 | |
668 | |
585 | =item $json_text = $json->encode ($perl_scalar) |
669 | =item $json_text = $json->encode ($perl_scalar) |
586 | |
670 | |
… | |
… | |
615 | => ([], 3) |
699 | => ([], 3) |
616 | |
700 | |
617 | =back |
701 | =back |
618 | |
702 | |
619 | |
703 | |
|
|
704 | =head1 INCREMENTAL PARSING |
|
|
705 | |
|
|
706 | In some cases, there is the need for incremental parsing of JSON |
|
|
707 | texts. While this module always has to keep both JSON text and resulting |
|
|
708 | Perl data structure in memory at one time, it does allow you to parse a |
|
|
709 | JSON stream incrementally. It does so by accumulating text until it has |
|
|
710 | a full JSON object, which it then can decode. This process is similar to |
|
|
711 | using C<decode_prefix> to see if a full JSON object is available, but is |
|
|
712 | much more efficient (JSON::XS will only attempt to parse the JSON text |
|
|
713 | once it is sure it has enough text to get a decisive result, using a very |
|
|
714 | simple but truly incremental parser). |
|
|
715 | |
|
|
716 | The following two methods deal with this. |
|
|
717 | |
|
|
718 | =over 4 |
|
|
719 | |
|
|
720 | =item [void, scalar or list context] = $json->incr_parse ([$string]) |
|
|
721 | |
|
|
722 | This is the central parsing function. It can both append new text and |
|
|
723 | extract objects from the stream accumulated so far (both of these |
|
|
724 | functions are optional). |
|
|
725 | |
|
|
726 | If C<$string> is given, then this string is appended to the already |
|
|
727 | existing JSON fragment stored in the C<$json> object. |
|
|
728 | |
|
|
729 | After that, if the function is called in void context, it will simply |
|
|
730 | return without doing anything further. This can be used to add more text |
|
|
731 | in as many chunks as you want. |
|
|
732 | |
|
|
733 | If the method is called in scalar context, then it will try to extract |
|
|
734 | exactly I<one> JSON object. If that is successful, it will return this |
|
|
735 | object, otherwise it will return C<undef>. If there is a parse error, |
|
|
736 | this method will croak just as C<decode> would do (one can then use |
|
|
737 | C<incr_skip> to skip the errornous part). This is the most common way of |
|
|
738 | using the method. |
|
|
739 | |
|
|
740 | And finally, in list context, it will try to extract as many objects |
|
|
741 | from the stream as it can find and return them, or the empty list |
|
|
742 | otherwise. For this to work, there must be no separators between the JSON |
|
|
743 | objects or arrays, instead they must be concatenated back-to-back. If |
|
|
744 | an error occurs, an exception will be raised as in the scalar context |
|
|
745 | case. Note that in this case, any previously-parsed JSON texts will be |
|
|
746 | lost. |
|
|
747 | |
|
|
748 | =item $lvalue_string = $json->incr_text |
|
|
749 | |
|
|
750 | This method returns the currently stored JSON fragment as an lvalue, that |
|
|
751 | is, you can manipulate it. This I<only> works when a preceding call to |
|
|
752 | C<incr_parse> in I<scalar context> successfully returned an object. Under |
|
|
753 | all other circumstances you must not call this function (I mean it. |
|
|
754 | although in simple tests it might actually work, it I<will> fail under |
|
|
755 | real world conditions). As a special exception, you can also call this |
|
|
756 | method before having parsed anything. |
|
|
757 | |
|
|
758 | This function is useful in two cases: a) finding the trailing text after a |
|
|
759 | JSON object or b) parsing multiple JSON objects separated by non-JSON text |
|
|
760 | (such as commas). |
|
|
761 | |
|
|
762 | =item $json->incr_skip |
|
|
763 | |
|
|
764 | This will reset the state of the incremental parser and will remove the |
|
|
765 | parsed text from the input buffer. This is useful after C<incr_parse> |
|
|
766 | died, in which case the input buffer and incremental parser state is left |
|
|
767 | unchanged, to skip the text parsed so far and to reset the parse state. |
|
|
768 | |
|
|
769 | =back |
|
|
770 | |
|
|
771 | =head2 LIMITATIONS |
|
|
772 | |
|
|
773 | All options that affect decoding are supported, except |
|
|
774 | C<allow_nonref>. The reason for this is that it cannot be made to |
|
|
775 | work sensibly: JSON objects and arrays are self-delimited, i.e. you can concatenate |
|
|
776 | them back to back and still decode them perfectly. This does not hold true |
|
|
777 | for JSON numbers, however. |
|
|
778 | |
|
|
779 | For example, is the string C<1> a single JSON number, or is it simply the |
|
|
780 | start of C<12>? Or is C<12> a single JSON number, or the concatenation |
|
|
781 | of C<1> and C<2>? In neither case you can tell, and this is why JSON::XS |
|
|
782 | takes the conservative route and disallows this case. |
|
|
783 | |
|
|
784 | =head2 EXAMPLES |
|
|
785 | |
|
|
786 | Some examples will make all this clearer. First, a simple example that |
|
|
787 | works similarly to C<decode_prefix>: We want to decode the JSON object at |
|
|
788 | the start of a string and identify the portion after the JSON object: |
|
|
789 | |
|
|
790 | my $text = "[1,2,3] hello"; |
|
|
791 | |
|
|
792 | my $json = new JSON::XS; |
|
|
793 | |
|
|
794 | my $obj = $json->incr_parse ($text) |
|
|
795 | or die "expected JSON object or array at beginning of string"; |
|
|
796 | |
|
|
797 | my $tail = $json->incr_text; |
|
|
798 | # $tail now contains " hello" |
|
|
799 | |
|
|
800 | Easy, isn't it? |
|
|
801 | |
|
|
802 | Now for a more complicated example: Imagine a hypothetical protocol where |
|
|
803 | you read some requests from a TCP stream, and each request is a JSON |
|
|
804 | array, without any separation between them (in fact, it is often useful to |
|
|
805 | use newlines as "separators", as these get interpreted as whitespace at |
|
|
806 | the start of the JSON text, which makes it possible to test said protocol |
|
|
807 | with C<telnet>...). |
|
|
808 | |
|
|
809 | Here is how you'd do it (it is trivial to write this in an event-based |
|
|
810 | manner): |
|
|
811 | |
|
|
812 | my $json = new JSON::XS; |
|
|
813 | |
|
|
814 | # read some data from the socket |
|
|
815 | while (sysread $socket, my $buf, 4096) { |
|
|
816 | |
|
|
817 | # split and decode as many requests as possible |
|
|
818 | for my $request ($json->incr_parse ($buf)) { |
|
|
819 | # act on the $request |
|
|
820 | } |
|
|
821 | } |
|
|
822 | |
|
|
823 | Another complicated example: Assume you have a string with JSON objects |
|
|
824 | or arrays, all separated by (optional) comma characters (e.g. C<[1],[2], |
|
|
825 | [3]>). To parse them, we have to skip the commas between the JSON texts, |
|
|
826 | and here is where the lvalue-ness of C<incr_text> comes in useful: |
|
|
827 | |
|
|
828 | my $text = "[1],[2], [3]"; |
|
|
829 | my $json = new JSON::XS; |
|
|
830 | |
|
|
831 | # void context, so no parsing done |
|
|
832 | $json->incr_parse ($text); |
|
|
833 | |
|
|
834 | # now extract as many objects as possible. note the |
|
|
835 | # use of scalar context so incr_text can be called. |
|
|
836 | while (my $obj = $json->incr_parse) { |
|
|
837 | # do something with $obj |
|
|
838 | |
|
|
839 | # now skip the optional comma |
|
|
840 | $json->incr_text =~ s/^ \s* , //x; |
|
|
841 | } |
|
|
842 | |
|
|
843 | Now lets go for a very complex example: Assume that you have a gigantic |
|
|
844 | JSON array-of-objects, many gigabytes in size, and you want to parse it, |
|
|
845 | but you cannot load it into memory fully (this has actually happened in |
|
|
846 | the real world :). |
|
|
847 | |
|
|
848 | Well, you lost, you have to implement your own JSON parser. But JSON::XS |
|
|
849 | can still help you: You implement a (very simple) array parser and let |
|
|
850 | JSON decode the array elements, which are all full JSON objects on their |
|
|
851 | own (this wouldn't work if the array elements could be JSON numbers, for |
|
|
852 | example): |
|
|
853 | |
|
|
854 | my $json = new JSON::XS; |
|
|
855 | |
|
|
856 | # open the monster |
|
|
857 | open my $fh, "<bigfile.json" |
|
|
858 | or die "bigfile: $!"; |
|
|
859 | |
|
|
860 | # first parse the initial "[" |
|
|
861 | for (;;) { |
|
|
862 | sysread $fh, my $buf, 65536 |
|
|
863 | or die "read error: $!"; |
|
|
864 | $json->incr_parse ($buf); # void context, so no parsing |
|
|
865 | |
|
|
866 | # Exit the loop once we found and removed(!) the initial "[". |
|
|
867 | # In essence, we are (ab-)using the $json object as a simple scalar |
|
|
868 | # we append data to. |
|
|
869 | last if $json->incr_text =~ s/^ \s* \[ //x; |
|
|
870 | } |
|
|
871 | |
|
|
872 | # now we have the skipped the initial "[", so continue |
|
|
873 | # parsing all the elements. |
|
|
874 | for (;;) { |
|
|
875 | # in this loop we read data until we got a single JSON object |
|
|
876 | for (;;) { |
|
|
877 | if (my $obj = $json->incr_parse) { |
|
|
878 | # do something with $obj |
|
|
879 | last; |
|
|
880 | } |
|
|
881 | |
|
|
882 | # add more data |
|
|
883 | sysread $fh, my $buf, 65536 |
|
|
884 | or die "read error: $!"; |
|
|
885 | $json->incr_parse ($buf); # void context, so no parsing |
|
|
886 | } |
|
|
887 | |
|
|
888 | # in this loop we read data until we either found and parsed the |
|
|
889 | # separating "," between elements, or the final "]" |
|
|
890 | for (;;) { |
|
|
891 | # first skip whitespace |
|
|
892 | $json->incr_text =~ s/^\s*//; |
|
|
893 | |
|
|
894 | # if we find "]", we are done |
|
|
895 | if ($json->incr_text =~ s/^\]//) { |
|
|
896 | print "finished.\n"; |
|
|
897 | exit; |
|
|
898 | } |
|
|
899 | |
|
|
900 | # if we find ",", we can continue with the next element |
|
|
901 | if ($json->incr_text =~ s/^,//) { |
|
|
902 | last; |
|
|
903 | } |
|
|
904 | |
|
|
905 | # if we find anything else, we have a parse error! |
|
|
906 | if (length $json->incr_text) { |
|
|
907 | die "parse error near ", $json->incr_text; |
|
|
908 | } |
|
|
909 | |
|
|
910 | # else add more data |
|
|
911 | sysread $fh, my $buf, 65536 |
|
|
912 | or die "read error: $!"; |
|
|
913 | $json->incr_parse ($buf); # void context, so no parsing |
|
|
914 | } |
|
|
915 | |
|
|
916 | This is a complex example, but most of the complexity comes from the fact |
|
|
917 | that we are trying to be correct (bear with me if I am wrong, I never ran |
|
|
918 | the above example :). |
|
|
919 | |
|
|
920 | |
|
|
921 | |
620 | =head1 MAPPING |
922 | =head1 MAPPING |
621 | |
923 | |
622 | This section describes how JSON::XS maps Perl values to JSON values and |
924 | This section describes how JSON::XS maps Perl values to JSON values and |
623 | vice versa. These mappings are designed to "do the right thing" in most |
925 | vice versa. These mappings are designed to "do the right thing" in most |
624 | circumstances automatically, preserving round-tripping characteristics |
926 | circumstances automatically, preserving round-tripping characteristics |
… | |
… | |
652 | |
954 | |
653 | A JSON number becomes either an integer, numeric (floating point) or |
955 | A JSON number becomes either an integer, numeric (floating point) or |
654 | string scalar in perl, depending on its range and any fractional parts. On |
956 | string scalar in perl, depending on its range and any fractional parts. On |
655 | the Perl level, there is no difference between those as Perl handles all |
957 | the Perl level, there is no difference between those as Perl handles all |
656 | the conversion details, but an integer may take slightly less memory and |
958 | the conversion details, but an integer may take slightly less memory and |
657 | might represent more values exactly than (floating point) numbers. |
959 | might represent more values exactly than floating point numbers. |
658 | |
960 | |
659 | If the number consists of digits only, JSON::XS will try to represent |
961 | If the number consists of digits only, JSON::XS will try to represent |
660 | it as an integer value. If that fails, it will try to represent it as |
962 | it as an integer value. If that fails, it will try to represent it as |
661 | a numeric (floating point) value if that is possible without loss of |
963 | a numeric (floating point) value if that is possible without loss of |
662 | precision. Otherwise it will preserve the number as a string value. |
964 | precision. Otherwise it will preserve the number as a string value (in |
|
|
965 | which case you lose roundtripping ability, as the JSON number will be |
|
|
966 | re-encoded toa JSON string). |
663 | |
967 | |
664 | Numbers containing a fractional or exponential part will always be |
968 | Numbers containing a fractional or exponential part will always be |
665 | represented as numeric (floating point) values, possibly at a loss of |
969 | represented as numeric (floating point) values, possibly at a loss of |
666 | precision. |
970 | precision (in which case you might lose perfect roundtripping ability, but |
667 | |
971 | the JSON number will still be re-encoded as a JSON number). |
668 | This might create round-tripping problems as numbers might become strings, |
|
|
669 | but as Perl is typeless there is no other way to do it. |
|
|
670 | |
972 | |
671 | =item true, false |
973 | =item true, false |
672 | |
974 | |
673 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
975 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
674 | respectively. They are overloaded to act almost exactly like the numbers |
976 | respectively. They are overloaded to act almost exactly like the numbers |
… | |
… | |
711 | Other unblessed references are generally not allowed and will cause an |
1013 | Other unblessed references are generally not allowed and will cause an |
712 | exception to be thrown, except for references to the integers C<0> and |
1014 | exception to be thrown, except for references to the integers C<0> and |
713 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
1015 | C<1>, which get turned into C<false> and C<true> atoms in JSON. You can |
714 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
1016 | also use C<JSON::XS::false> and C<JSON::XS::true> to improve readability. |
715 | |
1017 | |
716 | to_json [\0,JSON::XS::true] # yields [false,true] |
1018 | encode_json [\0, JSON::XS::true] # yields [false,true] |
717 | |
1019 | |
718 | =item JSON::XS::true, JSON::XS::false |
1020 | =item JSON::XS::true, JSON::XS::false |
719 | |
1021 | |
720 | These special values become JSON true and JSON false values, |
1022 | These special values become JSON true and JSON false values, |
721 | respectively. You can also use C<\1> and C<\0> directly if you want. |
1023 | respectively. You can also use C<\1> and C<\0> directly if you want. |
722 | |
1024 | |
723 | =item blessed objects |
1025 | =item blessed objects |
724 | |
1026 | |
725 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
1027 | Blessed objects are not directly representable in JSON. See the |
726 | underlying representation (hash- or arrayref), but this behaviour might |
1028 | C<allow_blessed> and C<convert_blessed> methods on various options on |
727 | change in future versions. |
1029 | how to deal with this: basically, you can choose between throwing an |
|
|
1030 | exception, encoding the reference as if it weren't blessed, or provide |
|
|
1031 | your own serialiser method. |
728 | |
1032 | |
729 | =item simple scalars |
1033 | =item simple scalars |
730 | |
1034 | |
731 | Simple Perl scalars (any scalar that is not a reference) are the most |
1035 | Simple Perl scalars (any scalar that is not a reference) are the most |
732 | difficult objects to encode: JSON::XS will encode undefined scalars as |
1036 | difficult objects to encode: JSON::XS will encode undefined scalars as |
733 | JSON null value, scalars that have last been used in a string context |
1037 | JSON C<null> values, scalars that have last been used in a string context |
734 | before encoding as JSON strings and anything else as number value: |
1038 | before encoding as JSON strings, and anything else as number value: |
735 | |
1039 | |
736 | # dump as number |
1040 | # dump as number |
737 | to_json [2] # yields [2] |
1041 | encode_json [2] # yields [2] |
738 | to_json [-3.0e17] # yields [-3e+17] |
1042 | encode_json [-3.0e17] # yields [-3e+17] |
739 | my $value = 5; to_json [$value] # yields [5] |
1043 | my $value = 5; encode_json [$value] # yields [5] |
740 | |
1044 | |
741 | # used as string, so dump as string |
1045 | # used as string, so dump as string |
742 | print $value; |
1046 | print $value; |
743 | to_json [$value] # yields ["5"] |
1047 | encode_json [$value] # yields ["5"] |
744 | |
1048 | |
745 | # undef becomes null |
1049 | # undef becomes null |
746 | to_json [undef] # yields [null] |
1050 | encode_json [undef] # yields [null] |
747 | |
1051 | |
748 | You can force the type to be a JSON string by stringifying it: |
1052 | You can force the type to be a JSON string by stringifying it: |
749 | |
1053 | |
750 | my $x = 3.1; # some variable containing a number |
1054 | my $x = 3.1; # some variable containing a number |
751 | "$x"; # stringified |
1055 | "$x"; # stringified |
… | |
… | |
757 | my $x = "3"; # some variable containing a string |
1061 | my $x = "3"; # some variable containing a string |
758 | $x += 0; # numify it, ensuring it will be dumped as a number |
1062 | $x += 0; # numify it, ensuring it will be dumped as a number |
759 | $x *= 1; # same thing, the choice is yours. |
1063 | $x *= 1; # same thing, the choice is yours. |
760 | |
1064 | |
761 | You can not currently force the type in other, less obscure, ways. Tell me |
1065 | You can not currently force the type in other, less obscure, ways. Tell me |
762 | if you need this capability. |
1066 | if you need this capability (but don't forget to explain why it's needed |
|
|
1067 | :). |
763 | |
1068 | |
764 | =back |
1069 | =back |
765 | |
1070 | |
766 | |
1071 | |
767 | =head1 COMPARISON |
1072 | =head1 ENCODING/CODESET FLAG NOTES |
768 | |
1073 | |
769 | As already mentioned, this module was created because none of the existing |
1074 | The interested reader might have seen a number of flags that signify |
770 | JSON modules could be made to work correctly. First I will describe the |
1075 | encodings or codesets - C<utf8>, C<latin1> and C<ascii>. There seems to be |
771 | problems (or pleasures) I encountered with various existing JSON modules, |
1076 | some confusion on what these do, so here is a short comparison: |
772 | followed by some benchmark values. JSON::XS was designed not to suffer |
1077 | |
773 | from any of these problems or limitations. |
1078 | C<utf8> controls whether the JSON text created by C<encode> (and expected |
|
|
1079 | by C<decode>) is UTF-8 encoded or not, while C<latin1> and C<ascii> only |
|
|
1080 | control whether C<encode> escapes character values outside their respective |
|
|
1081 | codeset range. Neither of these flags conflict with each other, although |
|
|
1082 | some combinations make less sense than others. |
|
|
1083 | |
|
|
1084 | Care has been taken to make all flags symmetrical with respect to |
|
|
1085 | C<encode> and C<decode>, that is, texts encoded with any combination of |
|
|
1086 | these flag values will be correctly decoded when the same flags are used |
|
|
1087 | - in general, if you use different flag settings while encoding vs. when |
|
|
1088 | decoding you likely have a bug somewhere. |
|
|
1089 | |
|
|
1090 | Below comes a verbose discussion of these flags. Note that a "codeset" is |
|
|
1091 | simply an abstract set of character-codepoint pairs, while an encoding |
|
|
1092 | takes those codepoint numbers and I<encodes> them, in our case into |
|
|
1093 | octets. Unicode is (among other things) a codeset, UTF-8 is an encoding, |
|
|
1094 | and ISO-8859-1 (= latin 1) and ASCII are both codesets I<and> encodings at |
|
|
1095 | the same time, which can be confusing. |
774 | |
1096 | |
775 | =over 4 |
1097 | =over 4 |
776 | |
1098 | |
777 | =item JSON 1.07 |
1099 | =item C<utf8> flag disabled |
778 | |
1100 | |
779 | Slow (but very portable, as it is written in pure Perl). |
1101 | When C<utf8> is disabled (the default), then C<encode>/C<decode> generate |
|
|
1102 | and expect Unicode strings, that is, characters with high ordinal Unicode |
|
|
1103 | values (> 255) will be encoded as such characters, and likewise such |
|
|
1104 | characters are decoded as-is, no canges to them will be done, except |
|
|
1105 | "(re-)interpreting" them as Unicode codepoints or Unicode characters, |
|
|
1106 | respectively (to Perl, these are the same thing in strings unless you do |
|
|
1107 | funny/weird/dumb stuff). |
780 | |
1108 | |
781 | Undocumented/buggy Unicode handling (how JSON handles Unicode values is |
1109 | This is useful when you want to do the encoding yourself (e.g. when you |
782 | undocumented. One can get far by feeding it Unicode strings and doing |
1110 | want to have UTF-16 encoded JSON texts) or when some other layer does |
783 | en-/decoding oneself, but Unicode escapes are not working properly). |
1111 | the encoding for you (for example, when printing to a terminal using a |
|
|
1112 | filehandle that transparently encodes to UTF-8 you certainly do NOT want |
|
|
1113 | to UTF-8 encode your data first and have Perl encode it another time). |
784 | |
1114 | |
785 | No round-tripping (strings get clobbered if they look like numbers, e.g. |
1115 | =item C<utf8> flag enabled |
786 | the string C<2.0> will encode to C<2.0> instead of C<"2.0">, and that will |
|
|
787 | decode into the number 2. |
|
|
788 | |
1116 | |
789 | =item JSON::PC 0.01 |
1117 | If the C<utf8>-flag is enabled, C<encode>/C<decode> will encode all |
|
|
1118 | characters using the corresponding UTF-8 multi-byte sequence, and will |
|
|
1119 | expect your input strings to be encoded as UTF-8, that is, no "character" |
|
|
1120 | of the input string must have any value > 255, as UTF-8 does not allow |
|
|
1121 | that. |
790 | |
1122 | |
791 | Very fast. |
1123 | The C<utf8> flag therefore switches between two modes: disabled means you |
|
|
1124 | will get a Unicode string in Perl, enabled means you get an UTF-8 encoded |
|
|
1125 | octet/binary string in Perl. |
792 | |
1126 | |
793 | Undocumented/buggy Unicode handling. |
1127 | =item C<latin1> or C<ascii> flags enabled |
794 | |
1128 | |
795 | No round-tripping. |
1129 | With C<latin1> (or C<ascii>) enabled, C<encode> will escape characters |
|
|
1130 | with ordinal values > 255 (> 127 with C<ascii>) and encode the remaining |
|
|
1131 | characters as specified by the C<utf8> flag. |
796 | |
1132 | |
797 | Has problems handling many Perl values (e.g. regex results and other magic |
1133 | If C<utf8> is disabled, then the result is also correctly encoded in those |
798 | values will make it croak). |
1134 | character sets (as both are proper subsets of Unicode, meaning that a |
|
|
1135 | Unicode string with all character values < 256 is the same thing as a |
|
|
1136 | ISO-8859-1 string, and a Unicode string with all character values < 128 is |
|
|
1137 | the same thing as an ASCII string in Perl). |
799 | |
1138 | |
800 | Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}> |
1139 | If C<utf8> is enabled, you still get a correct UTF-8-encoded string, |
801 | which is not a valid JSON text. |
1140 | regardless of these flags, just some more characters will be escaped using |
|
|
1141 | C<\uXXXX> then before. |
802 | |
1142 | |
803 | Unmaintained (maintainer unresponsive for many months, bugs are not |
1143 | Note that ISO-8859-1-I<encoded> strings are not compatible with UTF-8 |
804 | getting fixed). |
1144 | encoding, while ASCII-encoded strings are. That is because the ISO-8859-1 |
|
|
1145 | encoding is NOT a subset of UTF-8 (despite the ISO-8859-1 I<codeset> being |
|
|
1146 | a subset of Unicode), while ASCII is. |
805 | |
1147 | |
806 | =item JSON::Syck 0.21 |
1148 | Surprisingly, C<decode> will ignore these flags and so treat all input |
|
|
1149 | values as governed by the C<utf8> flag. If it is disabled, this allows you |
|
|
1150 | to decode ISO-8859-1- and ASCII-encoded strings, as both strict subsets of |
|
|
1151 | Unicode. If it is enabled, you can correctly decode UTF-8 encoded strings. |
807 | |
1152 | |
808 | Very buggy (often crashes). |
1153 | So neither C<latin1> nor C<ascii> are incompatible with the C<utf8> flag - |
|
|
1154 | they only govern when the JSON output engine escapes a character or not. |
809 | |
1155 | |
810 | Very inflexible (no human-readable format supported, format pretty much |
1156 | The main use for C<latin1> is to relatively efficiently store binary data |
811 | undocumented. I need at least a format for easy reading by humans and a |
1157 | as JSON, at the expense of breaking compatibility with most JSON decoders. |
812 | single-line compact format for use in a protocol, and preferably a way to |
|
|
813 | generate ASCII-only JSON texts). |
|
|
814 | |
1158 | |
815 | Completely broken (and confusingly documented) Unicode handling (Unicode |
1159 | The main use for C<ascii> is to force the output to not contain characters |
816 | escapes are not working properly, you need to set ImplicitUnicode to |
1160 | with values > 127, which means you can interpret the resulting string |
817 | I<different> values on en- and decoding to get symmetric behaviour). |
1161 | as UTF-8, ISO-8859-1, ASCII, KOI8-R or most about any character set and |
818 | |
1162 | 8-bit-encoding, and still get the same data structure back. This is useful |
819 | No round-tripping (simple cases work, but this depends on whether the scalar |
1163 | when your channel for JSON transfer is not 8-bit clean or the encoding |
820 | value was used in a numeric context or not). |
1164 | might be mangled in between (e.g. in mail), and works because ASCII is a |
821 | |
1165 | proper subset of most 8-bit and multibyte encodings in use in the world. |
822 | Dumping hashes may skip hash values depending on iterator state. |
|
|
823 | |
|
|
824 | Unmaintained (maintainer unresponsive for many months, bugs are not |
|
|
825 | getting fixed). |
|
|
826 | |
|
|
827 | Does not check input for validity (i.e. will accept non-JSON input and |
|
|
828 | return "something" instead of raising an exception. This is a security |
|
|
829 | issue: imagine two banks transferring money between each other using |
|
|
830 | JSON. One bank might parse a given non-JSON request and deduct money, |
|
|
831 | while the other might reject the transaction with a syntax error. While a |
|
|
832 | good protocol will at least recover, that is extra unnecessary work and |
|
|
833 | the transaction will still not succeed). |
|
|
834 | |
|
|
835 | =item JSON::DWIW 0.04 |
|
|
836 | |
|
|
837 | Very fast. Very natural. Very nice. |
|
|
838 | |
|
|
839 | Undocumented Unicode handling (but the best of the pack. Unicode escapes |
|
|
840 | still don't get parsed properly). |
|
|
841 | |
|
|
842 | Very inflexible. |
|
|
843 | |
|
|
844 | No round-tripping. |
|
|
845 | |
|
|
846 | Does not generate valid JSON texts (key strings are often unquoted, empty keys |
|
|
847 | result in nothing being output) |
|
|
848 | |
|
|
849 | Does not check input for validity. |
|
|
850 | |
1166 | |
851 | =back |
1167 | =back |
852 | |
1168 | |
853 | |
1169 | |
854 | =head2 JSON and YAML |
1170 | =head2 JSON and YAML |
855 | |
1171 | |
856 | You often hear that JSON is a subset (or a close subset) of YAML. This is, |
1172 | You often hear that JSON is a subset of YAML. This is, however, a mass |
857 | however, a mass hysteria and very far from the truth. In general, there is |
1173 | hysteria(*) and very far from the truth (as of the time of this writing), |
858 | no way to configure JSON::XS to output a data structure as valid YAML. |
1174 | so let me state it clearly: I<in general, there is no way to configure |
|
|
1175 | JSON::XS to output a data structure as valid YAML> that works in all |
|
|
1176 | cases. |
859 | |
1177 | |
860 | If you really must use JSON::XS to generate YAML, you should use this |
1178 | If you really must use JSON::XS to generate YAML, you should use this |
861 | algorithm (subject to change in future versions): |
1179 | algorithm (subject to change in future versions): |
862 | |
1180 | |
863 | my $to_yaml = JSON::XS->new->utf8->space_after (1); |
1181 | my $to_yaml = JSON::XS->new->utf8->space_after (1); |
864 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
1182 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
865 | |
1183 | |
866 | This will usually generate JSON texts that also parse as valid |
1184 | This will I<usually> generate JSON texts that also parse as valid |
867 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
1185 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
868 | lengths that JSON doesn't have, so you should make sure that your hash |
1186 | lengths that JSON doesn't have and also has different and incompatible |
|
|
1187 | unicode handling, so you should make sure that your hash keys are |
869 | keys are noticeably shorter than the 1024 characters YAML allows. |
1188 | noticeably shorter than the 1024 "stream characters" YAML allows and that |
|
|
1189 | you do not have characters with codepoint values outside the Unicode BMP |
|
|
1190 | (basic multilingual page). YAML also does not allow C<\/> sequences in |
|
|
1191 | strings (which JSON::XS does not I<currently> generate, but other JSON |
|
|
1192 | generators might). |
870 | |
1193 | |
871 | There might be other incompatibilities that I am not aware of. In general |
1194 | There might be other incompatibilities that I am not aware of (or the YAML |
|
|
1195 | specification has been changed yet again - it does so quite often). In |
872 | you should not try to generate YAML with a JSON generator or vice versa, |
1196 | general you should not try to generate YAML with a JSON generator or vice |
873 | or try to parse JSON with a YAML parser or vice versa: chances are high |
1197 | versa, or try to parse JSON with a YAML parser or vice versa: chances are |
874 | that you will run into severe interoperability problems. |
1198 | high that you will run into severe interoperability problems when you |
|
|
1199 | least expect it. |
|
|
1200 | |
|
|
1201 | =over 4 |
|
|
1202 | |
|
|
1203 | =item (*) |
|
|
1204 | |
|
|
1205 | I have been pressured multiple times by Brian Ingerson (one of the |
|
|
1206 | authors of the YAML specification) to remove this paragraph, despite him |
|
|
1207 | acknowledging that the actual incompatibilities exist. As I was personally |
|
|
1208 | bitten by this "JSON is YAML" lie, I refused and said I will continue to |
|
|
1209 | educate people about these issues, so others do not run into the same |
|
|
1210 | problem again and again. After this, Brian called me a (quote)I<complete |
|
|
1211 | and worthless idiot>(unquote). |
|
|
1212 | |
|
|
1213 | In my opinion, instead of pressuring and insulting people who actually |
|
|
1214 | clarify issues with YAML and the wrong statements of some of its |
|
|
1215 | proponents, I would kindly suggest reading the JSON spec (which is not |
|
|
1216 | that difficult or long) and finally make YAML compatible to it, and |
|
|
1217 | educating users about the changes, instead of spreading lies about the |
|
|
1218 | real compatibility for many I<years> and trying to silence people who |
|
|
1219 | point out that it isn't true. |
|
|
1220 | |
|
|
1221 | =back |
875 | |
1222 | |
876 | |
1223 | |
877 | =head2 SPEED |
1224 | =head2 SPEED |
878 | |
1225 | |
879 | It seems that JSON::XS is surprisingly fast, as shown in the following |
1226 | It seems that JSON::XS is surprisingly fast, as shown in the following |
880 | tables. They have been generated with the help of the C<eg/bench> program |
1227 | tables. They have been generated with the help of the C<eg/bench> program |
881 | in the JSON::XS distribution, to make it easy to compare on your own |
1228 | in the JSON::XS distribution, to make it easy to compare on your own |
882 | system. |
1229 | system. |
883 | |
1230 | |
884 | First comes a comparison between various modules using a very short |
1231 | First comes a comparison between various modules using |
885 | single-line JSON string: |
1232 | a very short single-line JSON string (also available at |
|
|
1233 | L<http://dist.schmorp.de/misc/json/short.json>). |
886 | |
1234 | |
887 | {"method": "handleMessage", "params": ["user1", "we were just talking"], \ |
1235 | {"method": "handleMessage", "params": ["user1", |
888 | "id": null, "array":[1,11,234,-5,1e5,1e7, true, false]} |
1236 | "we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7, |
|
|
1237 | true, false]} |
889 | |
1238 | |
890 | It shows the number of encodes/decodes per second (JSON::XS uses |
1239 | It shows the number of encodes/decodes per second (JSON::XS uses |
891 | the functional interface, while JSON::XS/2 uses the OO interface |
1240 | the functional interface, while JSON::XS/2 uses the OO interface |
892 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
1241 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
893 | shrink). Higher is better: |
1242 | shrink). Higher is better: |
894 | |
1243 | |
895 | Storable | 15779.925 | 14169.946 | |
|
|
896 | -----------+------------+------------+ |
|
|
897 | module | encode | decode | |
1244 | module | encode | decode | |
898 | -----------|------------|------------| |
1245 | -----------|------------|------------| |
899 | JSON | 4990.842 | 4088.813 | |
1246 | JSON 1.x | 4990.842 | 4088.813 | |
900 | JSON::DWIW | 51653.990 | 71575.154 | |
1247 | JSON::DWIW | 51653.990 | 71575.154 | |
901 | JSON::PC | 65948.176 | 74631.744 | |
1248 | JSON::PC | 65948.176 | 74631.744 | |
902 | JSON::PP | 8931.652 | 3817.168 | |
1249 | JSON::PP | 8931.652 | 3817.168 | |
903 | JSON::Syck | 24877.248 | 27776.848 | |
1250 | JSON::Syck | 24877.248 | 27776.848 | |
904 | JSON::XS | 388361.481 | 227951.304 | |
1251 | JSON::XS | 388361.481 | 227951.304 | |
… | |
… | |
911 | about three times faster on decoding, and over forty times faster |
1258 | about three times faster on decoding, and over forty times faster |
912 | than JSON, even with pretty-printing and key sorting. It also compares |
1259 | than JSON, even with pretty-printing and key sorting. It also compares |
913 | favourably to Storable for small amounts of data. |
1260 | favourably to Storable for small amounts of data. |
914 | |
1261 | |
915 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
1262 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
916 | search API (http://nanoref.com/yahooapis/mgPdGg): |
1263 | search API (L<http://dist.schmorp.de/misc/json/long.json>). |
917 | |
1264 | |
918 | module | encode | decode | |
1265 | module | encode | decode | |
919 | -----------|------------|------------| |
1266 | -----------|------------|------------| |
920 | JSON | 55.260 | 34.971 | |
1267 | JSON 1.x | 55.260 | 34.971 | |
921 | JSON::DWIW | 825.228 | 1082.513 | |
1268 | JSON::DWIW | 825.228 | 1082.513 | |
922 | JSON::PC | 3571.444 | 2394.829 | |
1269 | JSON::PC | 3571.444 | 2394.829 | |
923 | JSON::PP | 210.987 | 32.574 | |
1270 | JSON::PP | 210.987 | 32.574 | |
924 | JSON::Syck | 552.551 | 787.544 | |
1271 | JSON::Syck | 552.551 | 787.544 | |
925 | JSON::XS | 5780.463 | 4854.519 | |
1272 | JSON::XS | 5780.463 | 4854.519 | |
… | |
… | |
958 | |
1305 | |
959 | Third, JSON::XS recurses using the C stack when decoding objects and |
1306 | Third, JSON::XS recurses using the C stack when decoding objects and |
960 | arrays. The C stack is a limited resource: for instance, on my amd64 |
1307 | arrays. The C stack is a limited resource: for instance, on my amd64 |
961 | machine with 8MB of stack size I can decode around 180k nested arrays but |
1308 | machine with 8MB of stack size I can decode around 180k nested arrays but |
962 | only 14k nested JSON objects (due to perl itself recursing deeply on croak |
1309 | only 14k nested JSON objects (due to perl itself recursing deeply on croak |
963 | to free the temporary). If that is exceeded, the program crashes. to be |
1310 | to free the temporary). If that is exceeded, the program crashes. To be |
964 | conservative, the default nesting limit is set to 512. If your process |
1311 | conservative, the default nesting limit is set to 512. If your process |
965 | has a smaller stack, you should adjust this setting accordingly with the |
1312 | has a smaller stack, you should adjust this setting accordingly with the |
966 | C<max_depth> method. |
1313 | C<max_depth> method. |
967 | |
1314 | |
968 | And last but least, something else could bomb you that I forgot to think |
1315 | Something else could bomb you, too, that I forgot to think of. In that |
969 | of. In that case, you get to keep the pieces. I am always open for hints, |
1316 | case, you get to keep the pieces. I am always open for hints, though... |
970 | though... |
1317 | |
|
|
1318 | Also keep in mind that JSON::XS might leak contents of your Perl data |
|
|
1319 | structures in its error messages, so when you serialise sensitive |
|
|
1320 | information you might want to make sure that exceptions thrown by JSON::XS |
|
|
1321 | will not end up in front of untrusted eyes. |
971 | |
1322 | |
972 | If you are using JSON::XS to return packets to consumption |
1323 | If you are using JSON::XS to return packets to consumption |
973 | by JavaScript scripts in a browser you should have a look at |
1324 | by JavaScript scripts in a browser you should have a look at |
974 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether |
1325 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether |
975 | you are vulnerable to some common attack vectors (which really are browser |
1326 | you are vulnerable to some common attack vectors (which really are browser |
976 | design bugs, but it is still you who will have to deal with it, as major |
1327 | design bugs, but it is still you who will have to deal with it, as major |
977 | browser developers care only for features, not about doing security |
1328 | browser developers care only for features, not about getting security |
978 | right). |
1329 | right). |
979 | |
1330 | |
980 | |
1331 | |
981 | =head1 THREADS |
1332 | =head1 THREADS |
982 | |
1333 | |
983 | This module is I<not> guaranteed to be thread safe and there are no |
1334 | This module is I<not> guaranteed to be thread safe and there are no |
984 | plans to change this until Perl gets thread support (as opposed to the |
1335 | plans to change this until Perl gets thread support (as opposed to the |
985 | horribly slow so-called "threads" which are simply slow and bloated |
1336 | horribly slow so-called "threads" which are simply slow and bloated |
986 | process simulations - use fork, its I<much> faster, cheaper, better). |
1337 | process simulations - use fork, it's I<much> faster, cheaper, better). |
987 | |
1338 | |
988 | (It might actually work, but you have been warned). |
1339 | (It might actually work, but you have been warned). |
989 | |
1340 | |
990 | |
1341 | |
991 | =head1 BUGS |
1342 | =head1 BUGS |
992 | |
1343 | |
993 | While the goal of this module is to be correct, that unfortunately does |
1344 | While the goal of this module is to be correct, that unfortunately does |
994 | not mean its bug-free, only that I think its design is bug-free. It is |
1345 | not mean it's bug-free, only that I think its design is bug-free. If you |
995 | still relatively early in its development. If you keep reporting bugs they |
1346 | keep reporting bugs they will be fixed swiftly, though. |
996 | will be fixed swiftly, though. |
|
|
997 | |
1347 | |
998 | Please refrain from using rt.cpan.org or any other bug reporting |
1348 | Please refrain from using rt.cpan.org or any other bug reporting |
999 | service. I put the contact address into my modules for a reason. |
1349 | service. I put the contact address into my modules for a reason. |
1000 | |
1350 | |
1001 | =cut |
1351 | =cut |
… | |
… | |
1021 | "--" => sub { $_[0] = ${$_[0]} - 1 }, |
1371 | "--" => sub { $_[0] = ${$_[0]} - 1 }, |
1022 | fallback => 1; |
1372 | fallback => 1; |
1023 | |
1373 | |
1024 | 1; |
1374 | 1; |
1025 | |
1375 | |
|
|
1376 | =head1 SEE ALSO |
|
|
1377 | |
|
|
1378 | The F<json_xs> command line utility for quick experiments. |
|
|
1379 | |
1026 | =head1 AUTHOR |
1380 | =head1 AUTHOR |
1027 | |
1381 | |
1028 | Marc Lehmann <schmorp@schmorp.de> |
1382 | Marc Lehmann <schmorp@schmorp.de> |
1029 | http://home.schmorp.de/ |
1383 | http://home.schmorp.de/ |
1030 | |
1384 | |