| … | |
… | |
| 1153 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
1153 | my $yaml = $to_yaml->encode ($ref) . "\n"; |
| 1154 | |
1154 | |
| 1155 | This will *usually* generate JSON texts that also parse as valid YAML. |
1155 | This will *usually* generate JSON texts that also parse as valid YAML. |
| 1156 | Please note that YAML has hardcoded limits on (simple) object key |
1156 | Please note that YAML has hardcoded limits on (simple) object key |
| 1157 | lengths that JSON doesn't have and also has different and incompatible |
1157 | lengths that JSON doesn't have and also has different and incompatible |
| 1158 | unicode handling, so you should make sure that your hash keys are |
1158 | unicode character escape syntax, so you should make sure that your hash |
| 1159 | noticeably shorter than the 1024 "stream characters" YAML allows and |
1159 | keys are noticeably shorter than the 1024 "stream characters" YAML |
| 1160 | that you do not have characters with codepoint values outside the |
1160 | allows and that you do not have characters with codepoint values outside |
| 1161 | Unicode BMP (basic multilingual page). YAML also does not allow "\/" |
1161 | the Unicode BMP (basic multilingual page). YAML also does not allow "\/" |
| 1162 | sequences in strings (which JSON::XS does not *currently* generate, but |
1162 | sequences in strings (which JSON::XS does not *currently* generate, but |
| 1163 | other JSON generators might). |
1163 | other JSON generators might). |
| 1164 | |
1164 | |
| 1165 | There might be other incompatibilities that I am not aware of (or the |
1165 | There might be other incompatibilities that I am not aware of (or the |
| 1166 | YAML specification has been changed yet again - it does so quite often). |
1166 | YAML specification has been changed yet again - it does so quite often). |
| … | |
… | |
| 1183 | (which is not that difficult or long) and finally make YAML |
1183 | (which is not that difficult or long) and finally make YAML |
| 1184 | compatible to it, and educating users about the changes, instead of |
1184 | compatible to it, and educating users about the changes, instead of |
| 1185 | spreading lies about the real compatibility for many *years* and |
1185 | spreading lies about the real compatibility for many *years* and |
| 1186 | trying to silence people who point out that it isn't true. |
1186 | trying to silence people who point out that it isn't true. |
| 1187 | |
1187 | |
|
|
1188 | Addendum/2009: the YAML 1.2 spec is still incomaptible with JSON, |
|
|
1189 | even though the incompatibilities have been documented (and are |
|
|
1190 | known to Brian) for many years and the spec makes explicit claims |
|
|
1191 | that YAML is a superset of JSON. It would be so easy to fix, but |
|
|
1192 | apparently, bullying and corrupting userdata is so much easier. |
|
|
1193 | |
| 1188 | SPEED |
1194 | SPEED |
| 1189 | It seems that JSON::XS is surprisingly fast, as shown in the following |
1195 | It seems that JSON::XS is surprisingly fast, as shown in the following |
| 1190 | tables. They have been generated with the help of the "eg/bench" program |
1196 | tables. They have been generated with the help of the "eg/bench" program |
| 1191 | in the JSON::XS distribution, to make it easy to compare on your own |
1197 | in the JSON::XS distribution, to make it easy to compare on your own |
| 1192 | system. |
1198 | system. |
| … | |
… | |
| 1195 | single-line JSON string (also available at |
1201 | single-line JSON string (also available at |
| 1196 | <http://dist.schmorp.de/misc/json/short.json>). |
1202 | <http://dist.schmorp.de/misc/json/short.json>). |
| 1197 | |
1203 | |
| 1198 | {"method": "handleMessage", "params": ["user1", |
1204 | {"method": "handleMessage", "params": ["user1", |
| 1199 | "we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7, |
1205 | "we were just talking"], "id": null, "array":[1,11,234,-5,1e5,1e7, |
| 1200 | true, false]} |
1206 | 1, 0]} |
| 1201 | |
1207 | |
| 1202 | It shows the number of encodes/decodes per second (JSON::XS uses the |
1208 | It shows the number of encodes/decodes per second (JSON::XS uses the |
| 1203 | functional interface, while JSON::XS/2 uses the OO interface with |
1209 | functional interface, while JSON::XS/2 uses the OO interface with |
| 1204 | pretty-printing and hashkey sorting enabled, JSON::XS/3 enables shrink). |
1210 | pretty-printing and hashkey sorting enabled, JSON::XS/3 enables shrink. |
| 1205 | Higher is better: |
1211 | JSON::DWIW/DS uses the deserialise function, while JSON::DWIW::FJ uses |
|
|
1212 | the from_json method). Higher is better: |
| 1206 | |
1213 | |
| 1207 | module | encode | decode | |
1214 | module | encode | decode | |
| 1208 | -----------|------------|------------| |
1215 | --------------|------------|------------| |
| 1209 | JSON 1.x | 4990.842 | 4088.813 | |
1216 | JSON::DWIW/DS | 86302.551 | 102300.098 | |
| 1210 | JSON::DWIW | 51653.990 | 71575.154 | |
1217 | JSON::DWIW/FJ | 86302.551 | 75983.768 | |
| 1211 | JSON::PC | 65948.176 | 74631.744 | |
1218 | JSON::PP | 15827.562 | 6638.658 | |
| 1212 | JSON::PP | 8931.652 | 3817.168 | |
1219 | JSON::Syck | 63358.066 | 47662.545 | |
| 1213 | JSON::Syck | 24877.248 | 27776.848 | |
1220 | JSON::XS | 511500.488 | 511500.488 | |
| 1214 | JSON::XS | 388361.481 | 227951.304 | |
1221 | JSON::XS/2 | 291271.111 | 388361.481 | |
| 1215 | JSON::XS/2 | 227951.304 | 218453.333 | |
1222 | JSON::XS/3 | 361577.931 | 361577.931 | |
| 1216 | JSON::XS/3 | 338250.323 | 218453.333 | |
1223 | Storable | 66788.280 | 265462.278 | |
| 1217 | Storable | 16500.016 | 135300.129 | |
|
|
| 1218 | -----------+------------+------------+ |
1224 | --------------+------------+------------+ |
| 1219 | |
1225 | |
| 1220 | That is, JSON::XS is about five times faster than JSON::DWIW on |
1226 | That is, JSON::XS is almost six times faster than JSON::DWIW on |
| 1221 | encoding, about three times faster on decoding, and over forty times |
1227 | encoding, about five times faster on decoding, and over thirty to |
| 1222 | faster than JSON, even with pretty-printing and key sorting. It also |
1228 | seventy times faster than JSON's pure perl implementation. It also |
| 1223 | compares favourably to Storable for small amounts of data. |
1229 | compares favourably to Storable for small amounts of data. |
| 1224 | |
1230 | |
| 1225 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
1231 | Using a longer test string (roughly 18KB, generated from Yahoo! Locals |
| 1226 | search API (<http://dist.schmorp.de/misc/json/long.json>). |
1232 | search API (<http://dist.schmorp.de/misc/json/long.json>). |
| 1227 | |
1233 | |
| 1228 | module | encode | decode | |
1234 | module | encode | decode | |
| 1229 | -----------|------------|------------| |
1235 | --------------|------------|------------| |
| 1230 | JSON 1.x | 55.260 | 34.971 | |
1236 | JSON::DWIW/DS | 1647.927 | 2673.916 | |
| 1231 | JSON::DWIW | 825.228 | 1082.513 | |
1237 | JSON::DWIW/FJ | 1630.249 | 2596.128 | |
| 1232 | JSON::PC | 3571.444 | 2394.829 | |
|
|
| 1233 | JSON::PP | 210.987 | 32.574 | |
1238 | JSON::PP | 400.640 | 62.311 | |
| 1234 | JSON::Syck | 552.551 | 787.544 | |
1239 | JSON::Syck | 1481.040 | 1524.869 | |
| 1235 | JSON::XS | 5780.463 | 4854.519 | |
1240 | JSON::XS | 20661.596 | 9541.183 | |
| 1236 | JSON::XS/2 | 3869.998 | 4798.975 | |
1241 | JSON::XS/2 | 10683.403 | 9416.938 | |
| 1237 | JSON::XS/3 | 5862.880 | 4798.975 | |
1242 | JSON::XS/3 | 20661.596 | 9400.054 | |
| 1238 | Storable | 4445.002 | 5235.027 | |
1243 | Storable | 19765.806 | 10000.725 | |
| 1239 | -----------+------------+------------+ |
1244 | --------------+------------+------------+ |
| 1240 | |
1245 | |
| 1241 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
1246 | Again, JSON::XS leads by far (except for Storable which non-surprisingly |
| 1242 | decodes faster). |
1247 | decodes a bit faster). |
| 1243 | |
1248 | |
| 1244 | On large strings containing lots of high Unicode characters, some |
1249 | On large strings containing lots of high Unicode characters, some |
| 1245 | modules (such as JSON::PC) seem to decode faster than JSON::XS, but the |
1250 | modules (such as JSON::PC) seem to decode faster than JSON::XS, but the |
| 1246 | result will be broken due to missing (or wrong) Unicode handling. Others |
1251 | result will be broken due to missing (or wrong) Unicode handling. Others |
| 1247 | refuse to decode or encode properly, so it was impossible to prepare a |
1252 | refuse to decode or encode properly, so it was impossible to prepare a |
| … | |
… | |
| 1282 | information you might want to make sure that exceptions thrown by |
1287 | information you might want to make sure that exceptions thrown by |
| 1283 | JSON::XS will not end up in front of untrusted eyes. |
1288 | JSON::XS will not end up in front of untrusted eyes. |
| 1284 | |
1289 | |
| 1285 | If you are using JSON::XS to return packets to consumption by JavaScript |
1290 | If you are using JSON::XS to return packets to consumption by JavaScript |
| 1286 | scripts in a browser you should have a look at |
1291 | scripts in a browser you should have a look at |
| 1287 | <http://jpsykes.com/47/practical-csrf-and-json-security> to see whether |
1292 | <http://blog.archive.jpsykes.com/47/practical-csrf-and-json-security/> |
| 1288 | you are vulnerable to some common attack vectors (which really are |
1293 | to see whether you are vulnerable to some common attack vectors (which |
| 1289 | browser design bugs, but it is still you who will have to deal with it, |
1294 | really are browser design bugs, but it is still you who will have to |
| 1290 | as major browser developers care only for features, not about getting |
1295 | deal with it, as major browser developers care only for features, not |
| 1291 | security right). |
1296 | about getting security right). |
| 1292 | |
1297 | |
| 1293 | THREADS |
1298 | THREADS |
| 1294 | This module is *not* guaranteed to be thread safe and there are no plans |
1299 | This module is *not* guaranteed to be thread safe and there are no plans |
| 1295 | to change this until Perl gets thread support (as opposed to the |
1300 | to change this until Perl gets thread support (as opposed to the |
| 1296 | horribly slow so-called "threads" which are simply slow and bloated |
1301 | horribly slow so-called "threads" which are simply slow and bloated |
