4 ms·

> Saying something is immutable has different implications than saying "I want it cached for 10 years". Only if you have a system that you keep for more than 1

by jonknee 10y ago

> Saying something is immutable has different implications than saying "I want it cached for 10 years". Only if you have a system that you keep for more than 10 years. If a browser dumps stuff that it was told it can keep for a decade that means it can also dump stuff that it was told will never change. If the cache is full of things that are immutable something still has to go.

Klathmon 10y ago
Oh definitely, I meant more in the sense of being able to evict things more "intelligently". If stuff needs to go, it needs to go. It's going to happen. But if you have to choose between a file which was told to be cached for 10 years, and one which was labeled "immutable" but hasn't been referenced on the page it was previously for the last 10 loads, it might be a better choice to evict the immutable one.
- jacobsenscott 10y ago
  So I can build a site that stuffs your cache full of "immutable" content, and all your frequently used "cache for 10 years" stuff gets evicted?
  - Klathmon 10y ago
    You can already do that... Generally browser caches are "last used first out". So if you start stuffing the cache with a bunch of stuff you can already push the oldest out. And if you fill the whole thing you'll remove everything else. It was actually quite a problem on mobile browsers for a while. IIRC iOS had something like a 10MB cache for the longest time. A few heavy websites and your whole cache would cycle through. Android had a 5MB cache at one point as well! A shitty news site can already fill that single handedly. But my idea here (which I gave about 5 minutes of thought...) Was that immutable content would be evicted before the "10 year" stuff. The idea being that if something replaced an immutable "thing" it could be evicted much sooner. I'm not sure if it would really help at all, just kind of throwing out some ideas.

by jonknee 10y ago

Klathmon 10y ago

Oh definitely, I meant more in the sense of being able to evict things more "intelligently". If stuff needs to go, it needs to go. It's going to happen. But if you have to choose between a file which was told to be cached for 10 years, and one which was labeled "immutable" but hasn't been referenced on the page it was previously for the last 10 loads, it might be a better choice to evict the immutable one.

jacobsenscott 10y ago
So I can build a site that stuffs your cache full of "immutable" content, and all your frequently used "cache for 10 years" stuff gets evicted?
- Klathmon 10y ago
  You can already do that... Generally browser caches are "last used first out". So if you start stuffing the cache with a bunch of stuff you can already push the oldest out. And if you fill the whole thing you'll remove everything else. It was actually quite a problem on mobile browsers for a while. IIRC iOS had something like a 10MB cache for the longest time. A few heavy websites and your whole cache would cycle through. Android had a 5MB cache at one point as well! A shitty news site can already fill that single handedly. But my idea here (which I gave about 5 minutes of thought...) Was that immutable content would be evicted before the "10 year" stuff. The idea being that if something replaced an immutable "thing" it could be evicted much sooner. I'm not sure if it would really help at all, just kind of throwing out some ideas.