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 | JSON::XS - 正しくて高速な JSON シリアライザ/デシリアライザ |
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6 | (http://fleur.hio.jp/perldoc/mix/lib/JSON/XS.html) |
4 | |
7 | |
5 | =head1 SYNOPSIS |
8 | =head1 SYNOPSIS |
6 | |
9 | |
7 | use JSON::XS; |
10 | use JSON::XS; |
8 | |
11 | |
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16 | |
19 | |
17 | $coder = JSON::XS->new->ascii->pretty->allow_nonref; |
20 | $coder = JSON::XS->new->ascii->pretty->allow_nonref; |
18 | $pretty_printed_unencoded = $coder->encode ($perl_scalar); |
21 | $pretty_printed_unencoded = $coder->encode ($perl_scalar); |
19 | $perl_scalar = $coder->decode ($unicode_json_text); |
22 | $perl_scalar = $coder->decode ($unicode_json_text); |
20 | |
23 | |
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24 | # Note that JSON version 2.0 and above will automatically use JSON::XS |
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25 | # if available, at virtually no speed overhead either, so you should |
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26 | # be able to just: |
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27 | |
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28 | use JSON; |
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29 | |
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30 | # and do the same things, except that you have a pure-perl fallback now. |
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31 | |
21 | =head1 DESCRIPTION |
32 | =head1 DESCRIPTION |
22 | |
33 | |
23 | This module converts Perl data structures to JSON and vice versa. Its |
34 | This module converts Perl data structures to JSON and vice versa. Its |
24 | primary goal is to be I<correct> and its secondary goal is to be |
35 | primary goal is to be I<correct> and its secondary goal is to be |
25 | I<fast>. To reach the latter goal it was written in C. |
36 | I<fast>. To reach the latter goal it was written in C. |
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37 | |
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38 | Beginning with version 2.0 of the JSON module, when both JSON and |
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39 | JSON::XS are installed, then JSON will fall back on JSON::XS (this can be |
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40 | overriden) with no overhead due to emulation (by inheritign constructor |
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41 | and methods). If JSON::XS is not available, it will fall back to the |
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42 | compatible JSON::PP module as backend, so using JSON instead of JSON::XS |
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43 | gives you a portable JSON API that can be fast when you need and doesn't |
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44 | require a C compiler when that is a problem. |
26 | |
45 | |
27 | As this is the n-th-something JSON module on CPAN, what was the reason |
46 | As this is the n-th-something JSON module on CPAN, what was the reason |
28 | to write yet another JSON module? While it seems there are many JSON |
47 | to write yet another JSON module? While it seems there are many JSON |
29 | modules, none of them correctly handle all corner cases, and in most cases |
48 | modules, none of them correctly handle all corner cases, and in most cases |
30 | their maintainers are unresponsive, gone missing, or not listening to bug |
49 | their maintainers are unresponsive, gone missing, or not listening to bug |
… | |
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37 | |
56 | |
38 | =head2 FEATURES |
57 | =head2 FEATURES |
39 | |
58 | |
40 | =over 4 |
59 | =over 4 |
41 | |
60 | |
42 | =item * correct unicode handling |
61 | =item * correct Unicode handling |
43 | |
62 | |
44 | This module knows how to handle Unicode, and even documents how and when |
63 | This module knows how to handle Unicode, and even documents how and when |
45 | it does so. |
64 | it does so. |
46 | |
65 | |
47 | =item * round-trip integrity |
66 | =item * round-trip integrity |
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67 | This module has both a simple functional interface as well as an OO |
86 | This module has both a simple functional interface as well as an OO |
68 | interface. |
87 | interface. |
69 | |
88 | |
70 | =item * reasonably versatile output formats |
89 | =item * reasonably versatile output formats |
71 | |
90 | |
72 | You can choose between the most compact guarenteed single-line format |
91 | You can choose between the most compact guaranteed single-line format |
73 | possible (nice for simple line-based protocols), a pure-ascii format |
92 | possible (nice for simple line-based protocols), a pure-ascii format |
74 | (for when your transport is not 8-bit clean, still supports the whole |
93 | (for when your transport is not 8-bit clean, still supports the whole |
75 | unicode range), or a pretty-printed format (for when you want to read that |
94 | Unicode range), or a pretty-printed format (for when you want to read that |
76 | stuff). Or you can combine those features in whatever way you like. |
95 | stuff). Or you can combine those features in whatever way you like. |
77 | |
96 | |
78 | =back |
97 | =back |
79 | |
98 | |
80 | =cut |
99 | =cut |
81 | |
100 | |
82 | package JSON::XS; |
101 | package JSON::XS; |
83 | |
102 | |
84 | use strict; |
103 | use strict; |
85 | |
104 | |
86 | our $VERSION = '1.4'; |
105 | our $VERSION = '2.0'; |
87 | our @ISA = qw(Exporter); |
106 | our @ISA = qw(Exporter); |
88 | |
107 | |
89 | our @EXPORT = qw(to_json from_json); |
108 | our @EXPORT = qw(to_json from_json); |
90 | |
109 | |
91 | use Exporter; |
110 | use Exporter; |
92 | use XSLoader; |
111 | use XSLoader; |
93 | |
112 | |
94 | =head1 FUNCTIONAL INTERFACE |
113 | =head1 FUNCTIONAL INTERFACE |
95 | |
114 | |
96 | The following convinience methods are provided by this module. They are |
115 | The following convenience methods are provided by this module. They are |
97 | exported by default: |
116 | exported by default: |
98 | |
117 | |
99 | =over 4 |
118 | =over 4 |
100 | |
119 | |
101 | =item $json_text = to_json $perl_scalar |
120 | =item $json_text = to_json $perl_scalar |
102 | |
121 | |
103 | Converts the given Perl data structure (a simple scalar or a reference to |
122 | Converts the given Perl data structure to a UTF-8 encoded, binary string |
104 | a hash or array) to a UTF-8 encoded, binary string (that is, the string contains |
123 | (that is, the string contains octets only). Croaks on error. |
105 | octets only). Croaks on error. |
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106 | |
124 | |
107 | This function call is functionally identical to: |
125 | This function call is functionally identical to: |
108 | |
126 | |
109 | $json_text = JSON::XS->new->utf8->encode ($perl_scalar) |
127 | $json_text = JSON::XS->new->utf8->encode ($perl_scalar) |
110 | |
128 | |
111 | except being faster. |
129 | except being faster. |
112 | |
130 | |
113 | =item $perl_scalar = from_json $json_text |
131 | =item $perl_scalar = from_json $json_text |
114 | |
132 | |
115 | The opposite of C<to_json>: expects an UTF-8 (binary) string and tries to |
133 | The opposite of C<to_json>: expects an UTF-8 (binary) string and tries |
116 | parse that as an UTF-8 encoded JSON text, returning the resulting simple |
134 | to parse that as an UTF-8 encoded JSON text, returning the resulting |
117 | scalar or reference. Croaks on error. |
135 | reference. Croaks on error. |
118 | |
136 | |
119 | This function call is functionally identical to: |
137 | This function call is functionally identical to: |
120 | |
138 | |
121 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
139 | $perl_scalar = JSON::XS->new->utf8->decode ($json_text) |
122 | |
140 | |
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132 | Perl. |
150 | Perl. |
133 | |
151 | |
134 | =back |
152 | =back |
135 | |
153 | |
136 | |
154 | |
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155 | =head1 A FEW NOTES ON UNICODE AND PERL |
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156 | |
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157 | Since this often leads to confusion, here are a few very clear words on |
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158 | how Unicode works in Perl, modulo bugs. |
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159 | |
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160 | =over 4 |
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161 | |
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162 | =item 1. Perl strings can store characters with ordinal values > 255. |
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163 | |
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164 | This enables you to store Unicode characters as single characters in a |
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165 | Perl string - very natural. |
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166 | |
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167 | =item 2. Perl does I<not> associate an encoding with your strings. |
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168 | |
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169 | Unless you force it to, e.g. when matching it against a regex, or printing |
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170 | the scalar to a file, in which case Perl either interprets your string as |
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171 | locale-encoded text, octets/binary, or as Unicode, depending on various |
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172 | settings. In no case is an encoding stored together with your data, it is |
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173 | I<use> that decides encoding, not any magical metadata. |
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174 | |
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175 | =item 3. The internal utf-8 flag has no meaning with regards to the |
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176 | encoding of your string. |
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177 | |
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178 | Just ignore that flag unless you debug a Perl bug, a module written in |
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179 | XS or want to dive into the internals of perl. Otherwise it will only |
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180 | confuse you, as, despite the name, it says nothing about how your string |
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181 | is encoded. You can have Unicode strings with that flag set, with that |
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182 | flag clear, and you can have binary data with that flag set and that flag |
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183 | clear. Other possibilities exist, too. |
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184 | |
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185 | If you didn't know about that flag, just the better, pretend it doesn't |
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186 | exist. |
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187 | |
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188 | =item 4. A "Unicode String" is simply a string where each character can be |
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189 | validly interpreted as a Unicode codepoint. |
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190 | |
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191 | If you have UTF-8 encoded data, it is no longer a Unicode string, but a |
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192 | Unicode string encoded in UTF-8, giving you a binary string. |
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193 | |
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194 | =item 5. A string containing "high" (> 255) character values is I<not> a UTF-8 string. |
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195 | |
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196 | It's a fact. Learn to live with it. |
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197 | |
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198 | =back |
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199 | |
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200 | I hope this helps :) |
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201 | |
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202 | |
137 | =head1 OBJECT-ORIENTED INTERFACE |
203 | =head1 OBJECT-ORIENTED INTERFACE |
138 | |
204 | |
139 | The object oriented interface lets you configure your own encoding or |
205 | The object oriented interface lets you configure your own encoding or |
140 | decoding style, within the limits of supported formats. |
206 | decoding style, within the limits of supported formats. |
141 | |
207 | |
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152 | my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]}) |
218 | my $json = JSON::XS->new->utf8->space_after->encode ({a => [1,2]}) |
153 | => {"a": [1, 2]} |
219 | => {"a": [1, 2]} |
154 | |
220 | |
155 | =item $json = $json->ascii ([$enable]) |
221 | =item $json = $json->ascii ([$enable]) |
156 | |
222 | |
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223 | =item $enabled = $json->get_ascii |
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224 | |
157 | If C<$enable> is true (or missing), then the C<encode> method will not |
225 | If C<$enable> is true (or missing), then the C<encode> method will not |
158 | generate characters outside the code range C<0..127> (which is ASCII). Any |
226 | generate characters outside the code range C<0..127> (which is ASCII). Any |
159 | unicode characters outside that range will be escaped using either a |
227 | Unicode characters outside that range will be escaped using either a |
160 | single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, |
228 | single \uXXXX (BMP characters) or a double \uHHHH\uLLLLL escape sequence, |
161 | as per RFC4627. The resulting encoded JSON text can be treated as a native |
229 | as per RFC4627. The resulting encoded JSON text can be treated as a native |
162 | unicode string, an ascii-encoded, latin1-encoded or UTF-8 encoded string, |
230 | Unicode string, an ascii-encoded, latin1-encoded or UTF-8 encoded string, |
163 | or any other superset of ASCII. |
231 | or any other superset of ASCII. |
164 | |
232 | |
165 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
233 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
166 | characters unless required by the JSON syntax or other flags. This results |
234 | characters unless required by the JSON syntax or other flags. This results |
167 | in a faster and more compact format. |
235 | in a faster and more compact format. |
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173 | JSON::XS->new->ascii (1)->encode ([chr 0x10401]) |
241 | JSON::XS->new->ascii (1)->encode ([chr 0x10401]) |
174 | => ["\ud801\udc01"] |
242 | => ["\ud801\udc01"] |
175 | |
243 | |
176 | =item $json = $json->latin1 ([$enable]) |
244 | =item $json = $json->latin1 ([$enable]) |
177 | |
245 | |
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246 | =item $enabled = $json->get_latin1 |
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247 | |
178 | If C<$enable> is true (or missing), then the C<encode> method will encode |
248 | If C<$enable> is true (or missing), then the C<encode> method will encode |
179 | the resulting JSON text as latin1 (or iso-8859-1), escaping any characters |
249 | the resulting JSON text as latin1 (or iso-8859-1), escaping any characters |
180 | outside the code range C<0..255>. The resulting string can be treated as a |
250 | outside the code range C<0..255>. The resulting string can be treated as a |
181 | latin1-encoded JSON text or a native unicode string. The C<decode> method |
251 | latin1-encoded JSON text or a native Unicode string. The C<decode> method |
182 | will not be affected in any way by this flag, as C<decode> by default |
252 | will not be affected in any way by this flag, as C<decode> by default |
183 | expects unicode, which is a strict superset of latin1. |
253 | expects Unicode, which is a strict superset of latin1. |
184 | |
254 | |
185 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
255 | If C<$enable> is false, then the C<encode> method will not escape Unicode |
186 | characters unless required by the JSON syntax or other flags. |
256 | characters unless required by the JSON syntax or other flags. |
187 | |
257 | |
188 | The main use for this flag is efficiently encoding binary data as JSON |
258 | The main use for this flag is efficiently encoding binary data as JSON |
189 | text, as most octets will not be escaped, resulting in a smaller encoded |
259 | text, as most octets will not be escaped, resulting in a smaller encoded |
190 | size. The disadvantage is that the resulting JSON text is encoded |
260 | size. The disadvantage is that the resulting JSON text is encoded |
191 | in latin1 (and must correctly be treated as such when storing and |
261 | in latin1 (and must correctly be treated as such when storing and |
192 | transfering), a rare encoding for JSON. It is therefore most useful when |
262 | transferring), a rare encoding for JSON. It is therefore most useful when |
193 | you want to store data structures known to contain binary data efficiently |
263 | you want to store data structures known to contain binary data efficiently |
194 | in files or databases, not when talking to other JSON encoders/decoders. |
264 | in files or databases, not when talking to other JSON encoders/decoders. |
195 | |
265 | |
196 | JSON::XS->new->latin1->encode (["\x{89}\x{abc}"] |
266 | JSON::XS->new->latin1->encode (["\x{89}\x{abc}"] |
197 | => ["\x{89}\\u0abc"] # (perl syntax, U+abc escaped, U+89 not) |
267 | => ["\x{89}\\u0abc"] # (perl syntax, U+abc escaped, U+89 not) |
198 | |
268 | |
199 | =item $json = $json->utf8 ([$enable]) |
269 | =item $json = $json->utf8 ([$enable]) |
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270 | |
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271 | =item $enabled = $json->get_utf8 |
200 | |
272 | |
201 | If C<$enable> is true (or missing), then the C<encode> method will encode |
273 | If C<$enable> is true (or missing), then the C<encode> method will encode |
202 | the JSON result into UTF-8, as required by many protocols, while the |
274 | the JSON result into UTF-8, as required by many protocols, while the |
203 | C<decode> method expects to be handled an UTF-8-encoded string. Please |
275 | C<decode> method expects to be handled an UTF-8-encoded string. Please |
204 | note that UTF-8-encoded strings do not contain any characters outside the |
276 | note that UTF-8-encoded strings do not contain any characters outside the |
205 | range C<0..255>, they are thus useful for bytewise/binary I/O. In future |
277 | range C<0..255>, they are thus useful for bytewise/binary I/O. In future |
206 | versions, enabling this option might enable autodetection of the UTF-16 |
278 | versions, enabling this option might enable autodetection of the UTF-16 |
207 | and UTF-32 encoding families, as described in RFC4627. |
279 | and UTF-32 encoding families, as described in RFC4627. |
208 | |
280 | |
209 | If C<$enable> is false, then the C<encode> method will return the JSON |
281 | If C<$enable> is false, then the C<encode> method will return the JSON |
210 | string as a (non-encoded) unicode string, while C<decode> expects thus a |
282 | string as a (non-encoded) Unicode string, while C<decode> expects thus a |
211 | unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs |
283 | Unicode string. Any decoding or encoding (e.g. to UTF-8 or UTF-16) needs |
212 | to be done yourself, e.g. using the Encode module. |
284 | to be done yourself, e.g. using the Encode module. |
213 | |
285 | |
214 | Example, output UTF-16BE-encoded JSON: |
286 | Example, output UTF-16BE-encoded JSON: |
215 | |
287 | |
216 | use Encode; |
288 | use Encode; |
… | |
… | |
238 | ] |
310 | ] |
239 | } |
311 | } |
240 | |
312 | |
241 | =item $json = $json->indent ([$enable]) |
313 | =item $json = $json->indent ([$enable]) |
242 | |
314 | |
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315 | =item $enabled = $json->get_indent |
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316 | |
243 | If C<$enable> is true (or missing), then the C<encode> method will use a multiline |
317 | If C<$enable> is true (or missing), then the C<encode> method will use a multiline |
244 | format as output, putting every array member or object/hash key-value pair |
318 | format as output, putting every array member or object/hash key-value pair |
245 | into its own line, identing them properly. |
319 | into its own line, indenting them properly. |
246 | |
320 | |
247 | If C<$enable> is false, no newlines or indenting will be produced, and the |
321 | If C<$enable> is false, no newlines or indenting will be produced, and the |
248 | resulting JSON text is guarenteed not to contain any C<newlines>. |
322 | resulting JSON text is guaranteed not to contain any C<newlines>. |
249 | |
323 | |
250 | This setting has no effect when decoding JSON texts. |
324 | This setting has no effect when decoding JSON texts. |
251 | |
325 | |
252 | =item $json = $json->space_before ([$enable]) |
326 | =item $json = $json->space_before ([$enable]) |
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327 | |
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328 | =item $enabled = $json->get_space_before |
253 | |
329 | |
254 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
330 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
255 | optional space before the C<:> separating keys from values in JSON objects. |
331 | optional space before the C<:> separating keys from values in JSON objects. |
256 | |
332 | |
257 | If C<$enable> is false, then the C<encode> method will not add any extra |
333 | If C<$enable> is false, then the C<encode> method will not add any extra |
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263 | Example, space_before enabled, space_after and indent disabled: |
339 | Example, space_before enabled, space_after and indent disabled: |
264 | |
340 | |
265 | {"key" :"value"} |
341 | {"key" :"value"} |
266 | |
342 | |
267 | =item $json = $json->space_after ([$enable]) |
343 | =item $json = $json->space_after ([$enable]) |
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344 | |
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345 | =item $enabled = $json->get_space_after |
268 | |
346 | |
269 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
347 | If C<$enable> is true (or missing), then the C<encode> method will add an extra |
270 | optional space after the C<:> separating keys from values in JSON objects |
348 | optional space after the C<:> separating keys from values in JSON objects |
271 | and extra whitespace after the C<,> separating key-value pairs and array |
349 | and extra whitespace after the C<,> separating key-value pairs and array |
272 | members. |
350 | members. |
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278 | |
356 | |
279 | Example, space_before and indent disabled, space_after enabled: |
357 | Example, space_before and indent disabled, space_after enabled: |
280 | |
358 | |
281 | {"key": "value"} |
359 | {"key": "value"} |
282 | |
360 | |
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361 | =item $json = $json->relaxed ([$enable]) |
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362 | |
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363 | =item $enabled = $json->get_relaxed |
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364 | |
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365 | If C<$enable> is true (or missing), then C<decode> will accept some |
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366 | extensions to normal JSON syntax (see below). C<encode> will not be |
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367 | affected in anyway. I<Be aware that this option makes you accept invalid |
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368 | JSON texts as if they were valid!>. I suggest only to use this option to |
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369 | parse application-specific files written by humans (configuration files, |
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370 | resource files etc.) |
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371 | |
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372 | If C<$enable> is false (the default), then C<decode> will only accept |
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373 | valid JSON texts. |
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374 | |
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375 | Currently accepted extensions are: |
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376 | |
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377 | =over 4 |
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378 | |
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379 | =item * list items can have an end-comma |
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380 | |
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381 | JSON I<separates> array elements and key-value pairs with commas. This |
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382 | can be annoying if you write JSON texts manually and want to be able to |
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383 | quickly append elements, so this extension accepts comma at the end of |
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384 | such items not just between them: |
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385 | |
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386 | [ |
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387 | 1, |
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388 | 2, <- this comma not normally allowed |
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389 | ] |
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390 | { |
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391 | "k1": "v1", |
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392 | "k2": "v2", <- this comma not normally allowed |
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393 | } |
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394 | |
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395 | =item * shell-style '#'-comments |
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396 | |
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397 | Whenever JSON allows whitespace, shell-style comments are additionally |
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398 | allowed. They are terminated by the first carriage-return or line-feed |
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399 | character, after which more white-space and comments are allowed. |
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400 | |
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401 | [ |
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402 | 1, # this comment not allowed in JSON |
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403 | # neither this one... |
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404 | ] |
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405 | |
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406 | =back |
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407 | |
283 | =item $json = $json->canonical ([$enable]) |
408 | =item $json = $json->canonical ([$enable]) |
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409 | |
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410 | =item $enabled = $json->get_canonical |
284 | |
411 | |
285 | If C<$enable> is true (or missing), then the C<encode> method will output JSON objects |
412 | If C<$enable> is true (or missing), then the C<encode> method will output JSON objects |
286 | by sorting their keys. This is adding a comparatively high overhead. |
413 | by sorting their keys. This is adding a comparatively high overhead. |
287 | |
414 | |
288 | If C<$enable> is false, then the C<encode> method will output key-value |
415 | If C<$enable> is false, then the C<encode> method will output key-value |
289 | pairs in the order Perl stores them (which will likely change between runs |
416 | pairs in the order Perl stores them (which will likely change between runs |
290 | of the same script). |
417 | of the same script). |
291 | |
418 | |
292 | This option is useful if you want the same data structure to be encoded as |
419 | This option is useful if you want the same data structure to be encoded as |
293 | the same JSON text (given the same overall settings). If it is disabled, |
420 | the same JSON text (given the same overall settings). If it is disabled, |
294 | the same hash migh be encoded differently even if contains the same data, |
421 | the same hash might be encoded differently even if contains the same data, |
295 | as key-value pairs have no inherent ordering in Perl. |
422 | as key-value pairs have no inherent ordering in Perl. |
296 | |
423 | |
297 | This setting has no effect when decoding JSON texts. |
424 | This setting has no effect when decoding JSON texts. |
298 | |
425 | |
299 | =item $json = $json->allow_nonref ([$enable]) |
426 | =item $json = $json->allow_nonref ([$enable]) |
|
|
427 | |
|
|
428 | =item $enabled = $json->get_allow_nonref |
300 | |
429 | |
301 | If C<$enable> is true (or missing), then the C<encode> method can convert a |
430 | If C<$enable> is true (or missing), then the C<encode> method can convert a |
302 | non-reference into its corresponding string, number or null JSON value, |
431 | non-reference into its corresponding string, number or null JSON value, |
303 | which is an extension to RFC4627. Likewise, C<decode> will accept those JSON |
432 | which is an extension to RFC4627. Likewise, C<decode> will accept those JSON |
304 | values instead of croaking. |
433 | values instead of croaking. |
… | |
… | |
314 | JSON::XS->new->allow_nonref->encode ("Hello, World!") |
443 | JSON::XS->new->allow_nonref->encode ("Hello, World!") |
315 | => "Hello, World!" |
444 | => "Hello, World!" |
316 | |
445 | |
317 | =item $json = $json->allow_blessed ([$enable]) |
446 | =item $json = $json->allow_blessed ([$enable]) |
318 | |
447 | |
|
|
448 | =item $enabled = $json->get_allow_blessed |
|
|
449 | |
319 | If C<$enable> is true (or missing), then the C<encode> method will not |
450 | If C<$enable> is true (or missing), then the C<encode> method will not |
320 | barf when it encounters a blessed reference. Instead, the value of the |
451 | barf when it encounters a blessed reference. Instead, the value of the |
321 | B<convert_blessed> option will decide wether C<null> (C<convert_blessed> |
452 | B<convert_blessed> option will decide whether C<null> (C<convert_blessed> |
322 | disabled or no C<to_json> method found) or a representation of the |
453 | disabled or no C<TO_JSON> method found) or a representation of the |
323 | object (C<convert_blessed> enabled and C<to_json> method found) is being |
454 | object (C<convert_blessed> enabled and C<TO_JSON> method found) is being |
324 | encoded. Has no effect on C<decode>. |
455 | encoded. Has no effect on C<decode>. |
325 | |
456 | |
326 | If C<$enable> is false (the default), then C<encode> will throw an |
457 | If C<$enable> is false (the default), then C<encode> will throw an |
327 | exception when it encounters a blessed object. |
458 | exception when it encounters a blessed object. |
328 | |
459 | |
329 | =item $json = $json->convert_blessed ([$enable]) |
460 | =item $json = $json->convert_blessed ([$enable]) |
|
|
461 | |
|
|
462 | =item $enabled = $json->get_convert_blessed |
330 | |
463 | |
331 | If C<$enable> is true (or missing), then C<encode>, upon encountering a |
464 | If C<$enable> is true (or missing), then C<encode>, upon encountering a |
332 | blessed object, will check for the availability of the C<TO_JSON> method |
465 | blessed object, will check for the availability of the C<TO_JSON> method |
333 | on the object's class. If found, it will be called in scalar context |
466 | on the object's class. If found, it will be called in scalar context |
334 | and the resulting scalar will be encoded instead of the object. If no |
467 | and the resulting scalar will be encoded instead of the object. If no |
… | |
… | |
348 | enabled by this setting. |
481 | enabled by this setting. |
349 | |
482 | |
350 | If C<$enable> is false, then the C<allow_blessed> setting will decide what |
483 | If C<$enable> is false, then the C<allow_blessed> setting will decide what |
351 | to do when a blessed object is found. |
484 | to do when a blessed object is found. |
352 | |
485 | |
353 | =item $json = $json->filter_json_object ([$coderef]) |
486 | =item $json = $json->filter_json_object ([$coderef->($hashref)]) |
354 | |
487 | |
355 | When C<$coderef> is specified, it will be called from C<decode> each |
488 | When C<$coderef> is specified, it will be called from C<decode> each |
356 | time it decodes a JSON object. The only argument is a reference to the |
489 | time it decodes a JSON object. The only argument is a reference to the |
357 | newly-created hash. If the code references returns a single scalar (which |
490 | newly-created hash. If the code references returns a single scalar (which |
358 | need not be a reference), this value (i.e. a copy of that scalar to avoid |
491 | need not be a reference), this value (i.e. a copy of that scalar to avoid |
359 | aliasing) is inserted into the deserialised data structure. If it returns |
492 | aliasing) is inserted into the deserialised data structure. If it returns |
360 | an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the |
493 | an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the |
361 | original deserialised hash will be inserted. This setting can slow down |
494 | original deserialised hash will be inserted. This setting can slow down |
362 | decoding considerably. |
495 | decoding considerably. |
363 | |
496 | |
364 | When C<$coderef> is omitted or undefined, C<decode> will not change the |
497 | When C<$coderef> is omitted or undefined, any existing callback will |
365 | deserialised hash in any way. This is maximally fast. |
498 | be removed and C<decode> will not change the deserialised hash in any |
|
|
499 | way. |
366 | |
500 | |
367 | Example, convert all JSON objects into the integer 5: |
501 | Example, convert all JSON objects into the integer 5: |
368 | |
502 | |
369 | my $js = JSON::XS->new->filter_json_object (sub { 5 }); |
503 | my $js = JSON::XS->new->filter_json_object (sub { 5 }); |
370 | # returns [5] |
504 | # returns [5] |
371 | $js->decode ('[{}]') |
505 | $js->decode ('[{}]') |
372 | # throw an exception because allow_nonref is not enabled: |
506 | # throw an exception because allow_nonref is not enabled |
|
|
507 | # so a lone 5 is not allowed. |
373 | $js->decode ('{"a":1, "b":2}'); |
508 | $js->decode ('{"a":1, "b":2}'); |
374 | |
509 | |
375 | =item $json = $json->filter_json_single_key_object ([$coderef]) |
510 | =item $json = $json->filter_json_single_key_object ($key [=> $coderef->($value)]) |
376 | |
511 | |
377 | Works like C<filter_json_object>, but is only called for JSON objects |
512 | Works remotely similar to C<filter_json_object>, but is only called for |
378 | having only a single key. |
513 | JSON objects having a single key named C<$key>. |
379 | |
514 | |
380 | This C<$coderef> is called before the one specified via |
515 | This C<$coderef> is called before the one specified via |
381 | C<filter_json_object>, if any. If it returns something, that will be |
516 | C<filter_json_object>, if any. It gets passed the single value in the JSON |
382 | inserted into the data structure. If it returns nothing, the callback |
517 | object. If it returns a single value, it will be inserted into the data |
383 | from C<filter_json_object> will be called next. If you want to force |
518 | structure. If it returns nothing (not even C<undef> but the empty list), |
384 | insertion of single-key objects even in the presence of a mutating |
519 | the callback from C<filter_json_object> will be called next, as if no |
385 | C<filter_json_object> callback, simply return the passed hash. |
520 | single-key callback were specified. |
|
|
521 | |
|
|
522 | If C<$coderef> is omitted or undefined, the corresponding callback will be |
|
|
523 | disabled. There can only ever be one callback for a given key. |
386 | |
524 | |
387 | As this callback gets called less often then the C<filter_json_object> |
525 | As this callback gets called less often then the C<filter_json_object> |
388 | one, decoding speed will not usually suffer as much. Therefore, single-key |
526 | one, decoding speed will not usually suffer as much. Therefore, single-key |
389 | objects make excellent targets to serialise Perl objects into, especially |
527 | objects make excellent targets to serialise Perl objects into, especially |
390 | as single-key JSON objects are as close to the type-tagged value concept |
528 | as single-key JSON objects are as close to the type-tagged value concept |
391 | as JSON gets (its basically an ID/VALUE tuple). Of course, JSON does not |
529 | as JSON gets (it's basically an ID/VALUE tuple). Of course, JSON does not |
392 | support this in any way, so you need to make sure your data never looks |
530 | support this in any way, so you need to make sure your data never looks |
393 | like a serialised Perl hash. |
531 | like a serialised Perl hash. |
394 | |
532 | |
395 | Typical names for the single object key are C<__class_whatever__>, or |
533 | Typical names for the single object key are C<__class_whatever__>, or |
396 | C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even |
534 | C<$__dollars_are_rarely_used__$> or C<}ugly_brace_placement>, or even |
… | |
… | |
401 | into the corresponding C<< $WIDGET{<id>} >> object: |
539 | into the corresponding C<< $WIDGET{<id>} >> object: |
402 | |
540 | |
403 | # return whatever is in $WIDGET{5}: |
541 | # return whatever is in $WIDGET{5}: |
404 | JSON::XS |
542 | JSON::XS |
405 | ->new |
543 | ->new |
406 | ->filter_json_single_key_object (sub { |
544 | ->filter_json_single_key_object (__widget__ => sub { |
407 | exists $_[0]{__widget__} |
|
|
408 | ? $WIDGET{ $_[0]{__widget__} } |
545 | $WIDGET{ $_[0] } |
409 | : () |
|
|
410 | }) |
546 | }) |
411 | ->decode ('{"__widget__": 5') |
547 | ->decode ('{"__widget__": 5') |
412 | |
548 | |
413 | # this can be used with a TO_JSON method in some "widget" class |
549 | # this can be used with a TO_JSON method in some "widget" class |
414 | # for serialisation to json: |
550 | # for serialisation to json: |
… | |
… | |
422 | |
558 | |
423 | { __widget__ => $self->{id} } |
559 | { __widget__ => $self->{id} } |
424 | } |
560 | } |
425 | |
561 | |
426 | =item $json = $json->shrink ([$enable]) |
562 | =item $json = $json->shrink ([$enable]) |
|
|
563 | |
|
|
564 | =item $enabled = $json->get_shrink |
427 | |
565 | |
428 | Perl usually over-allocates memory a bit when allocating space for |
566 | Perl usually over-allocates memory a bit when allocating space for |
429 | strings. This flag optionally resizes strings generated by either |
567 | strings. This flag optionally resizes strings generated by either |
430 | C<encode> or C<decode> to their minimum size possible. This can save |
568 | C<encode> or C<decode> to their minimum size possible. This can save |
431 | memory when your JSON texts are either very very long or you have many |
569 | memory when your JSON texts are either very very long or you have many |
… | |
… | |
449 | strings that look like integers or floats into integers or floats |
587 | strings that look like integers or floats into integers or floats |
450 | internally (there is no difference on the Perl level), saving space. |
588 | internally (there is no difference on the Perl level), saving space. |
451 | |
589 | |
452 | =item $json = $json->max_depth ([$maximum_nesting_depth]) |
590 | =item $json = $json->max_depth ([$maximum_nesting_depth]) |
453 | |
591 | |
|
|
592 | =item $max_depth = $json->get_max_depth |
|
|
593 | |
454 | Sets the maximum nesting level (default C<512>) accepted while encoding |
594 | Sets the maximum nesting level (default C<512>) accepted while encoding |
455 | or decoding. If the JSON text or Perl data structure has an equal or |
595 | or decoding. If the JSON text or Perl data structure has an equal or |
456 | higher nesting level then this limit, then the encoder and decoder will |
596 | higher nesting level then this limit, then the encoder and decoder will |
457 | stop and croak at that point. |
597 | stop and croak at that point. |
458 | |
598 | |
… | |
… | |
469 | used, which is rarely useful. |
609 | used, which is rarely useful. |
470 | |
610 | |
471 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
611 | See SECURITY CONSIDERATIONS, below, for more info on why this is useful. |
472 | |
612 | |
473 | =item $json = $json->max_size ([$maximum_string_size]) |
613 | =item $json = $json->max_size ([$maximum_string_size]) |
|
|
614 | |
|
|
615 | =item $max_size = $json->get_max_size |
474 | |
616 | |
475 | Set the maximum length a JSON text may have (in bytes) where decoding is |
617 | Set the maximum length a JSON text may have (in bytes) where decoding is |
476 | being attempted. The default is C<0>, meaning no limit. When C<decode> |
618 | being attempted. The default is C<0>, meaning no limit. When C<decode> |
477 | is called on a string longer then this number of characters it will not |
619 | is called on a string longer then this number of characters it will not |
478 | attempt to decode the string but throw an exception. This setting has no |
620 | attempt to decode the string but throw an exception. This setting has no |
… | |
… | |
525 | vice versa. These mappings are designed to "do the right thing" in most |
667 | vice versa. These mappings are designed to "do the right thing" in most |
526 | circumstances automatically, preserving round-tripping characteristics |
668 | circumstances automatically, preserving round-tripping characteristics |
527 | (what you put in comes out as something equivalent). |
669 | (what you put in comes out as something equivalent). |
528 | |
670 | |
529 | For the more enlightened: note that in the following descriptions, |
671 | For the more enlightened: note that in the following descriptions, |
530 | lowercase I<perl> refers to the Perl interpreter, while uppcercase I<Perl> |
672 | lowercase I<perl> refers to the Perl interpreter, while uppercase I<Perl> |
531 | refers to the abstract Perl language itself. |
673 | refers to the abstract Perl language itself. |
532 | |
674 | |
533 | |
675 | |
534 | =head2 JSON -> PERL |
676 | =head2 JSON -> PERL |
535 | |
677 | |
536 | =over 4 |
678 | =over 4 |
537 | |
679 | |
538 | =item object |
680 | =item object |
539 | |
681 | |
540 | A JSON object becomes a reference to a hash in Perl. No ordering of object |
682 | A JSON object becomes a reference to a hash in Perl. No ordering of object |
541 | keys is preserved (JSON does not preserver object key ordering itself). |
683 | keys is preserved (JSON does not preserve object key ordering itself). |
542 | |
684 | |
543 | =item array |
685 | =item array |
544 | |
686 | |
545 | A JSON array becomes a reference to an array in Perl. |
687 | A JSON array becomes a reference to an array in Perl. |
546 | |
688 | |
… | |
… | |
550 | are represented by the same codepoints in the Perl string, so no manual |
692 | are represented by the same codepoints in the Perl string, so no manual |
551 | decoding is necessary. |
693 | decoding is necessary. |
552 | |
694 | |
553 | =item number |
695 | =item number |
554 | |
696 | |
555 | A JSON number becomes either an integer or numeric (floating point) |
697 | A JSON number becomes either an integer, numeric (floating point) or |
556 | scalar in perl, depending on its range and any fractional parts. On the |
698 | string scalar in perl, depending on its range and any fractional parts. On |
557 | Perl level, there is no difference between those as Perl handles all the |
699 | the Perl level, there is no difference between those as Perl handles all |
558 | conversion details, but an integer may take slightly less memory and might |
700 | the conversion details, but an integer may take slightly less memory and |
559 | represent more values exactly than (floating point) numbers. |
701 | might represent more values exactly than (floating point) numbers. |
|
|
702 | |
|
|
703 | If the number consists of digits only, JSON::XS will try to represent |
|
|
704 | it as an integer value. If that fails, it will try to represent it as |
|
|
705 | a numeric (floating point) value if that is possible without loss of |
|
|
706 | precision. Otherwise it will preserve the number as a string value. |
|
|
707 | |
|
|
708 | Numbers containing a fractional or exponential part will always be |
|
|
709 | represented as numeric (floating point) values, possibly at a loss of |
|
|
710 | precision. |
|
|
711 | |
|
|
712 | This might create round-tripping problems as numbers might become strings, |
|
|
713 | but as Perl is typeless there is no other way to do it. |
560 | |
714 | |
561 | =item true, false |
715 | =item true, false |
562 | |
716 | |
563 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
717 | These JSON atoms become C<JSON::XS::true> and C<JSON::XS::false>, |
564 | respectively. They are overloaded to act almost exactly like the numbers |
718 | respectively. They are overloaded to act almost exactly like the numbers |
565 | C<1> and C<0>. You can check wether a scalar is a JSON boolean by using |
719 | C<1> and C<0>. You can check whether a scalar is a JSON boolean by using |
566 | the C<JSON::XS::is_bool> function. |
720 | the C<JSON::XS::is_bool> function. |
567 | |
721 | |
568 | =item null |
722 | =item null |
569 | |
723 | |
570 | A JSON null atom becomes C<undef> in Perl. |
724 | A JSON null atom becomes C<undef> in Perl. |
… | |
… | |
606 | to_json [\0,JSON::XS::true] # yields [false,true] |
760 | to_json [\0,JSON::XS::true] # yields [false,true] |
607 | |
761 | |
608 | =item JSON::XS::true, JSON::XS::false |
762 | =item JSON::XS::true, JSON::XS::false |
609 | |
763 | |
610 | These special values become JSON true and JSON false values, |
764 | These special values become JSON true and JSON false values, |
611 | respectively. You cna alos use C<\1> and C<\0> directly if you want. |
765 | respectively. You can also use C<\1> and C<\0> directly if you want. |
612 | |
766 | |
613 | =item blessed objects |
767 | =item blessed objects |
614 | |
768 | |
615 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
769 | Blessed objects are not allowed. JSON::XS currently tries to encode their |
616 | underlying representation (hash- or arrayref), but this behaviour might |
770 | underlying representation (hash- or arrayref), but this behaviour might |
… | |
… | |
633 | to_json [$value] # yields ["5"] |
787 | to_json [$value] # yields ["5"] |
634 | |
788 | |
635 | # undef becomes null |
789 | # undef becomes null |
636 | to_json [undef] # yields [null] |
790 | to_json [undef] # yields [null] |
637 | |
791 | |
638 | You can force the type to be a string by stringifying it: |
792 | You can force the type to be a JSON string by stringifying it: |
639 | |
793 | |
640 | my $x = 3.1; # some variable containing a number |
794 | my $x = 3.1; # some variable containing a number |
641 | "$x"; # stringified |
795 | "$x"; # stringified |
642 | $x .= ""; # another, more awkward way to stringify |
796 | $x .= ""; # another, more awkward way to stringify |
643 | print $x; # perl does it for you, too, quite often |
797 | print $x; # perl does it for you, too, quite often |
644 | |
798 | |
645 | You can force the type to be a number by numifying it: |
799 | You can force the type to be a JSON number by numifying it: |
646 | |
800 | |
647 | my $x = "3"; # some variable containing a string |
801 | my $x = "3"; # some variable containing a string |
648 | $x += 0; # numify it, ensuring it will be dumped as a number |
802 | $x += 0; # numify it, ensuring it will be dumped as a number |
649 | $x *= 1; # same thing, the choise is yours. |
803 | $x *= 1; # same thing, the choice is yours. |
650 | |
804 | |
651 | You can not currently output JSON booleans or force the type in other, |
805 | You can not currently force the type in other, less obscure, ways. Tell me |
652 | less obscure, ways. Tell me if you need this capability. |
806 | if you need this capability. |
653 | |
807 | |
654 | =back |
808 | =back |
655 | |
809 | |
656 | |
810 | |
657 | =head1 COMPARISON |
811 | =head1 COMPARISON |
… | |
… | |
666 | |
820 | |
667 | =item JSON 1.07 |
821 | =item JSON 1.07 |
668 | |
822 | |
669 | Slow (but very portable, as it is written in pure Perl). |
823 | Slow (but very portable, as it is written in pure Perl). |
670 | |
824 | |
671 | Undocumented/buggy Unicode handling (how JSON handles unicode values is |
825 | Undocumented/buggy Unicode handling (how JSON handles Unicode values is |
672 | undocumented. One can get far by feeding it unicode strings and doing |
826 | undocumented. One can get far by feeding it Unicode strings and doing |
673 | en-/decoding oneself, but unicode escapes are not working properly). |
827 | en-/decoding oneself, but Unicode escapes are not working properly). |
674 | |
828 | |
675 | No roundtripping (strings get clobbered if they look like numbers, e.g. |
829 | No round-tripping (strings get clobbered if they look like numbers, e.g. |
676 | the string C<2.0> will encode to C<2.0> instead of C<"2.0">, and that will |
830 | the string C<2.0> will encode to C<2.0> instead of C<"2.0">, and that will |
677 | decode into the number 2. |
831 | decode into the number 2. |
678 | |
832 | |
679 | =item JSON::PC 0.01 |
833 | =item JSON::PC 0.01 |
680 | |
834 | |
681 | Very fast. |
835 | Very fast. |
682 | |
836 | |
683 | Undocumented/buggy Unicode handling. |
837 | Undocumented/buggy Unicode handling. |
684 | |
838 | |
685 | No roundtripping. |
839 | No round-tripping. |
686 | |
840 | |
687 | Has problems handling many Perl values (e.g. regex results and other magic |
841 | Has problems handling many Perl values (e.g. regex results and other magic |
688 | values will make it croak). |
842 | values will make it croak). |
689 | |
843 | |
690 | Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}> |
844 | Does not even generate valid JSON (C<{1,2}> gets converted to C<{1:2}> |
… | |
… | |
700 | Very inflexible (no human-readable format supported, format pretty much |
854 | Very inflexible (no human-readable format supported, format pretty much |
701 | undocumented. I need at least a format for easy reading by humans and a |
855 | undocumented. I need at least a format for easy reading by humans and a |
702 | single-line compact format for use in a protocol, and preferably a way to |
856 | single-line compact format for use in a protocol, and preferably a way to |
703 | generate ASCII-only JSON texts). |
857 | generate ASCII-only JSON texts). |
704 | |
858 | |
705 | Completely broken (and confusingly documented) Unicode handling (unicode |
859 | Completely broken (and confusingly documented) Unicode handling (Unicode |
706 | escapes are not working properly, you need to set ImplicitUnicode to |
860 | escapes are not working properly, you need to set ImplicitUnicode to |
707 | I<different> values on en- and decoding to get symmetric behaviour). |
861 | I<different> values on en- and decoding to get symmetric behaviour). |
708 | |
862 | |
709 | No roundtripping (simple cases work, but this depends on wether the scalar |
863 | No round-tripping (simple cases work, but this depends on whether the scalar |
710 | value was used in a numeric context or not). |
864 | value was used in a numeric context or not). |
711 | |
865 | |
712 | Dumping hashes may skip hash values depending on iterator state. |
866 | Dumping hashes may skip hash values depending on iterator state. |
713 | |
867 | |
714 | Unmaintained (maintainer unresponsive for many months, bugs are not |
868 | Unmaintained (maintainer unresponsive for many months, bugs are not |
715 | getting fixed). |
869 | getting fixed). |
716 | |
870 | |
717 | Does not check input for validity (i.e. will accept non-JSON input and |
871 | Does not check input for validity (i.e. will accept non-JSON input and |
718 | return "something" instead of raising an exception. This is a security |
872 | return "something" instead of raising an exception. This is a security |
719 | issue: imagine two banks transfering money between each other using |
873 | issue: imagine two banks transferring money between each other using |
720 | JSON. One bank might parse a given non-JSON request and deduct money, |
874 | JSON. One bank might parse a given non-JSON request and deduct money, |
721 | while the other might reject the transaction with a syntax error. While a |
875 | while the other might reject the transaction with a syntax error. While a |
722 | good protocol will at least recover, that is extra unnecessary work and |
876 | good protocol will at least recover, that is extra unnecessary work and |
723 | the transaction will still not succeed). |
877 | the transaction will still not succeed). |
724 | |
878 | |
725 | =item JSON::DWIW 0.04 |
879 | =item JSON::DWIW 0.04 |
726 | |
880 | |
727 | Very fast. Very natural. Very nice. |
881 | Very fast. Very natural. Very nice. |
728 | |
882 | |
729 | Undocumented unicode handling (but the best of the pack. Unicode escapes |
883 | Undocumented Unicode handling (but the best of the pack. Unicode escapes |
730 | still don't get parsed properly). |
884 | still don't get parsed properly). |
731 | |
885 | |
732 | Very inflexible. |
886 | Very inflexible. |
733 | |
887 | |
734 | No roundtripping. |
888 | No round-tripping. |
735 | |
889 | |
736 | Does not generate valid JSON texts (key strings are often unquoted, empty keys |
890 | Does not generate valid JSON texts (key strings are often unquoted, empty keys |
737 | result in nothing being output) |
891 | result in nothing being output) |
738 | |
892 | |
739 | Does not check input for validity. |
893 | Does not check input for validity. |
… | |
… | |
754 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
908 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
755 | |
909 | |
756 | This will usually generate JSON texts that also parse as valid |
910 | This will usually generate JSON texts that also parse as valid |
757 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
911 | YAML. Please note that YAML has hardcoded limits on (simple) object key |
758 | lengths that JSON doesn't have, so you should make sure that your hash |
912 | lengths that JSON doesn't have, so you should make sure that your hash |
759 | keys are noticably shorter than the 1024 characters YAML allows. |
913 | keys are noticeably shorter than the 1024 characters YAML allows. |
760 | |
914 | |
761 | There might be other incompatibilities that I am not aware of. In general |
915 | There might be other incompatibilities that I am not aware of. In general |
762 | you should not try to generate YAML with a JSON generator or vice versa, |
916 | you should not try to generate YAML with a JSON generator or vice versa, |
763 | or try to parse JSON with a YAML parser or vice versa: chances are high |
917 | or try to parse JSON with a YAML parser or vice versa: chances are high |
764 | that you will run into severe interoperability problems. |
918 | that you will run into severe interoperability problems. |
… | |
… | |
780 | It shows the number of encodes/decodes per second (JSON::XS uses |
934 | It shows the number of encodes/decodes per second (JSON::XS uses |
781 | the functional interface, while JSON::XS/2 uses the OO interface |
935 | the functional interface, while JSON::XS/2 uses the OO interface |
782 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
936 | with pretty-printing and hashkey sorting enabled, JSON::XS/3 enables |
783 | shrink). Higher is better: |
937 | shrink). Higher is better: |
784 | |
938 | |
785 | Storable | 15779.925 | 14169.946 | |
|
|
786 | -----------+------------+------------+ |
|
|
787 | module | encode | decode | |
939 | module | encode | decode | |
788 | -----------|------------|------------| |
940 | -----------|------------|------------| |
789 | JSON | 4990.842 | 4088.813 | |
941 | JSON 1.x | 4990.842 | 4088.813 | |
790 | JSON::DWIW | 51653.990 | 71575.154 | |
942 | JSON::DWIW | 51653.990 | 71575.154 | |
791 | JSON::PC | 65948.176 | 74631.744 | |
943 | JSON::PC | 65948.176 | 74631.744 | |
792 | JSON::PP | 8931.652 | 3817.168 | |
944 | JSON::PP | 8931.652 | 3817.168 | |
793 | JSON::Syck | 24877.248 | 27776.848 | |
945 | JSON::Syck | 24877.248 | 27776.848 | |
794 | JSON::XS | 388361.481 | 227951.304 | |
946 | JSON::XS | 388361.481 | 227951.304 | |
… | |
… | |
796 | JSON::XS/3 | 338250.323 | 218453.333 | |
948 | JSON::XS/3 | 338250.323 | 218453.333 | |
797 | Storable | 16500.016 | 135300.129 | |
949 | Storable | 16500.016 | 135300.129 | |
798 | -----------+------------+------------+ |
950 | -----------+------------+------------+ |
799 | |
951 | |
800 | That is, JSON::XS is about five times faster than JSON::DWIW on encoding, |
952 | That is, JSON::XS is about five times faster than JSON::DWIW on encoding, |
801 | about three times faster on decoding, and over fourty times faster |
953 | about three times faster on decoding, and over forty times faster |
802 | than JSON, even with pretty-printing and key sorting. It also compares |
954 | than JSON, even with pretty-printing and key sorting. It also compares |
803 | favourably to Storable for small amounts of data. |
955 | favourably to Storable for small amounts of data. |
804 | |
956 | |
805 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
957 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
806 | search API (http://nanoref.com/yahooapis/mgPdGg): |
958 | search API (http://nanoref.com/yahooapis/mgPdGg): |
807 | |
959 | |
808 | module | encode | decode | |
960 | module | encode | decode | |
809 | -----------|------------|------------| |
961 | -----------|------------|------------| |
810 | JSON | 55.260 | 34.971 | |
962 | JSON 1.x | 55.260 | 34.971 | |
811 | JSON::DWIW | 825.228 | 1082.513 | |
963 | JSON::DWIW | 825.228 | 1082.513 | |
812 | JSON::PC | 3571.444 | 2394.829 | |
964 | JSON::PC | 3571.444 | 2394.829 | |
813 | JSON::PP | 210.987 | 32.574 | |
965 | JSON::PP | 210.987 | 32.574 | |
814 | JSON::Syck | 552.551 | 787.544 | |
966 | JSON::Syck | 552.551 | 787.544 | |
815 | JSON::XS | 5780.463 | 4854.519 | |
967 | JSON::XS | 5780.463 | 4854.519 | |
… | |
… | |
819 | -----------+------------+------------+ |
971 | -----------+------------+------------+ |
820 | |
972 | |
821 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
973 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
822 | decodes faster). |
974 | decodes faster). |
823 | |
975 | |
824 | On large strings containing lots of high unicode characters, some modules |
976 | On large strings containing lots of high Unicode characters, some modules |
825 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
977 | (such as JSON::PC) seem to decode faster than JSON::XS, but the result |
826 | will be broken due to missing (or wrong) unicode handling. Others refuse |
978 | will be broken due to missing (or wrong) Unicode handling. Others refuse |
827 | to decode or encode properly, so it was impossible to prepare a fair |
979 | to decode or encode properly, so it was impossible to prepare a fair |
828 | comparison table for that case. |
980 | comparison table for that case. |
829 | |
981 | |
830 | |
982 | |
831 | =head1 SECURITY CONSIDERATIONS |
983 | =head1 SECURITY CONSIDERATIONS |
… | |
… | |
837 | any buffer overflows. Obviously, this module should ensure that and I am |
989 | any buffer overflows. Obviously, this module should ensure that and I am |
838 | trying hard on making that true, but you never know. |
990 | trying hard on making that true, but you never know. |
839 | |
991 | |
840 | Second, you need to avoid resource-starving attacks. That means you should |
992 | Second, you need to avoid resource-starving attacks. That means you should |
841 | limit the size of JSON texts you accept, or make sure then when your |
993 | limit the size of JSON texts you accept, or make sure then when your |
842 | resources run out, thats just fine (e.g. by using a separate process that |
994 | resources run out, that's just fine (e.g. by using a separate process that |
843 | can crash safely). The size of a JSON text in octets or characters is |
995 | can crash safely). The size of a JSON text in octets or characters is |
844 | usually a good indication of the size of the resources required to decode |
996 | usually a good indication of the size of the resources required to decode |
845 | it into a Perl structure. While JSON::XS can check the size of the JSON |
997 | it into a Perl structure. While JSON::XS can check the size of the JSON |
846 | text, it might be too late when you already have it in memory, so you |
998 | text, it might be too late when you already have it in memory, so you |
847 | might want to check the size before you accept the string. |
999 | might want to check the size before you accept the string. |
… | |
… | |
858 | And last but least, something else could bomb you that I forgot to think |
1010 | And last but least, something else could bomb you that I forgot to think |
859 | of. In that case, you get to keep the pieces. I am always open for hints, |
1011 | of. In that case, you get to keep the pieces. I am always open for hints, |
860 | though... |
1012 | though... |
861 | |
1013 | |
862 | If you are using JSON::XS to return packets to consumption |
1014 | If you are using JSON::XS to return packets to consumption |
863 | by javascript scripts in a browser you should have a look at |
1015 | by JavaScript scripts in a browser you should have a look at |
864 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see wether |
1016 | L<http://jpsykes.com/47/practical-csrf-and-json-security> to see whether |
865 | you are vulnerable to some common attack vectors (which really are browser |
1017 | you are vulnerable to some common attack vectors (which really are browser |
866 | design bugs, but it is still you who will have to deal with it, as major |
1018 | design bugs, but it is still you who will have to deal with it, as major |
867 | browser developers care only for features, not about doing security |
1019 | browser developers care only for features, not about doing security |
868 | right). |
1020 | right). |
869 | |
1021 | |
870 | |
1022 | |
|
|
1023 | =head1 THREADS |
|
|
1024 | |
|
|
1025 | This module is I<not> guaranteed to be thread safe and there are no |
|
|
1026 | plans to change this until Perl gets thread support (as opposed to the |
|
|
1027 | horribly slow so-called "threads" which are simply slow and bloated |
|
|
1028 | process simulations - use fork, its I<much> faster, cheaper, better). |
|
|
1029 | |
|
|
1030 | (It might actually work, but you have been warned). |
|
|
1031 | |
|
|
1032 | |
871 | =head1 BUGS |
1033 | =head1 BUGS |
872 | |
1034 | |
873 | While the goal of this module is to be correct, that unfortunately does |
1035 | While the goal of this module is to be correct, that unfortunately does |
874 | not mean its bug-free, only that I think its design is bug-free. It is |
1036 | not mean its bug-free, only that I think its design is bug-free. It is |
875 | still relatively early in its development. If you keep reporting bugs they |
1037 | still relatively early in its development. If you keep reporting bugs they |
876 | will be fixed swiftly, though. |
1038 | will be fixed swiftly, though. |
877 | |
1039 | |
|
|
1040 | Please refrain from using rt.cpan.org or any other bug reporting |
|
|
1041 | service. I put the contact address into my modules for a reason. |
|
|
1042 | |
878 | =cut |
1043 | =cut |
879 | |
1044 | |
880 | our $true = do { bless \(my $dummy = "1"), "JSON::XS::Boolean" }; |
1045 | our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; |
881 | our $false = do { bless \(my $dummy = "0"), "JSON::XS::Boolean" }; |
1046 | our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; |
882 | |
1047 | |
883 | sub true() { $true } |
1048 | sub true() { $true } |
884 | sub false() { $false } |
1049 | sub false() { $false } |
885 | |
1050 | |
886 | sub is_bool($) { |
1051 | sub is_bool($) { |