{"id":513,"date":"2012-11-09T00:09:47","date_gmt":"2012-11-08T22:09:47","guid":{"rendered":"http:\/\/blog.nebule.org\/?p=513"},"modified":"2016-03-29T19:04:41","modified_gmt":"2016-03-29T17:04:41","slug":"compressibilite-des-liens","status":"publish","type":"post","link":"http:\/\/blog.nebule.org\/?p=513","title":{"rendered":"Compressibilit\u00e9 des liens"},"content":{"rendered":"

Les exp\u00e9riences autour de nebule se font aujourd’hui via des \u00e9changes en html. Il pourront se faire plus tard via tout protocole d’\u00e9change. ind\u00e9pendamment du stockage des liens, il sera utile de les compresser lors de leur transmission pour gagner de la bande passante r\u00e9seau.<\/p>\n

Prenons un exemple.
\n– Lien 1 :
\n signature=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:sha256<\/code><\/span>
\n signataire=975571a8a470a6d975662e284f5ef1bd0396c06b31a2207b81bef2e24c5bf0c5<\/code><\/span>
\n date=20121019201038<\/code><\/span>
\n action=L<\/code><\/span>
\n objet source=975571a8a470a6d975662e284f5ef1bd0396c06b31a2207b81bef2e24c5bf0c5<\/code><\/span>
\n objet destination=970bdb5df1e795929c71503d578b1b6bed601bb65ed7b8e4ae77dd85125d7864<\/code><\/span>
\n objet meta=93d4a5f3ef1fc5c89df3c986ca74187561666e3341c73ceb57f5a09822e96570<\/code><\/span>
\n– Lien 2 :
\n signature=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:sha256<\/code><\/span>
\n signataire=975571a8a470a6d975662e284f5ef1bd0396c06b31a2207b81bef2e24c5bf0c5<\/code><\/span>
\n date=20121019201039<\/code><\/span>
\n action=L<\/code><\/span>
\n objet source=975571a8a470a6d975662e284f5ef1bd0396c06b31a2207b81bef2e24c5bf0c5<\/code><\/span>
\n objet destination=7c512aaa1c5e3837fe2667afe1146261ef8b9eb355f8078e72900f845ada93fe<\/code><\/span>
\n objet meta=a6b4edb371e864e4d17754188166f981f9a9a78e11273c7d8c87b4363c20af9d<\/code><\/span>
\n– Lien 3 :
\n signature=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:sha256<\/code><\/span>
\n signataire=975571a8a470a6d975662e284f5ef1bd0396c06b31a2207b81bef2e24c5bf0c5<\/code><\/span>
\n date=20121019201039<\/code><\/span>
\n action=F<\/code><\/span>
\n objet source=6a4b7f1100b87044b21f0300eb5c8b627e440e6c239b7dc64767dc16fab38719<\/code><\/span>
\n objet destination=975571a8a470a6d975662e284f5ef1bd0396c06b31a2207b81bef2e24c5bf0c5<\/code><\/span>
\n objet meta=<\/span>
\n– Lien 4 :
\n signature=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:sha256<\/code><\/span>
\n signataire=975571a8a470a6d975662e284f5ef1bd0396c06b31a2207b81bef2e24c5bf0c5<\/code><\/span>
\n date=20121019201040<\/code><\/span>
\n action=L<\/code><\/span>
\n objet source=975571a8a470a6d975662e284f5ef1bd0396c06b31a2207b81bef2e24c5bf0c5<\/code><\/span>
\n objet destination=23297ddeeaaa2f42728eb1ddc6a88d1406bcff6f885de529e0d132418d0a5fb1<\/code><\/span>
\n objet meta=<\/span><\/p>\n

On remarque que, \u00e0 part la date<\/span> et l’action<\/span>, les autres champs du lien sont repr\u00e9sent\u00e9s par des donn\u00e9es \u00e0 caract\u00e8re pseudo-al\u00e9atoire. En physique, on dirait que c’est du bruit blanc, sans dominante d’une valeur sur une autre. Le tout est parfaitement impr\u00e9visible donc au premier abord impossible \u00e0 compresser.<\/p>\n

La date<\/span> semble peu varier l’un lien \u00e0 l’autre, on peu d\u00e9j\u00e0 gagner un peu<\/em> l\u00e0-dessus, un peu plus de 1,5%.<\/p>\n

On peut quand m\u00eame voir que certains autres champs se r\u00e9p\u00e8tent d’un lien \u00e0 l’autre, comme le signataire<\/span> par exemple. Ce m\u00eame signataire appara\u00eet parfois dans les champs source<\/span> ou destination<\/span>. Compresser un seul lien ne sert pas \u00e0 grand chose, mais \u00e0 partir de 2 liens, le gain n’est plus n\u00e9gligeable. Ainsi, le champs d’une entit\u00e9 repr\u00e9sente 8%, soit 8% de gain de compression directe. Le double si l’entit\u00e9 appara\u00eet en source<\/span> ou destination<\/span>.<\/p>\n

On gagne donc automatiquement au minimum 9,5% de gain de compression lorsque l’on transmet les liens d’un objet. Un essai pratique \u00e0 montr\u00e9 un gain de compression de 44% sur les liens d’une entit\u00e9 et de 38% sur un les liens d’autres objets.<\/p>\n","protected":false},"excerpt":{"rendered":"

Les exp\u00e9riences autour de nebule se font aujourd’hui via des \u00e9changes en html. Il pourront se faire plus tard via tout protocole d’\u00e9change. ind\u00e9pendamment du stockage des liens, il sera utile de les compresser lors de leur transmission pour gagner de la bande passante r\u00e9seau.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[99,113,24,35],"tags":[155],"_links":{"self":[{"href":"http:\/\/blog.nebule.org\/index.php?rest_route=\/wp\/v2\/posts\/513"}],"collection":[{"href":"http:\/\/blog.nebule.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blog.nebule.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blog.nebule.org\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/blog.nebule.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=513"}],"version-history":[{"count":1,"href":"http:\/\/blog.nebule.org\/index.php?rest_route=\/wp\/v2\/posts\/513\/revisions"}],"predecessor-version":[{"id":2327,"href":"http:\/\/blog.nebule.org\/index.php?rest_route=\/wp\/v2\/posts\/513\/revisions\/2327"}],"wp:attachment":[{"href":"http:\/\/blog.nebule.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=513"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blog.nebule.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=513"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blog.nebule.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=513"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}