Episode 431: Feb 25th, 2026
Links
Topics
- https://www.keanu.codes/?code=431
- Brought to you by HTTP code 431
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/431
- Today will be a slightly shorter episode.
- No episode next week!
- Is it cleaner to just create a specialized protocol handler for cached newtab resources in this configuration? ```HTML
- Add a moz-newtab-cached protocol handler that can run in the privileged about content process.
- It’s job will be to get a remote stream from the parent for script, or for styles.
- When the parent receives the request, the parent will get the hash value from prefs.
- Will retrieve the cache entry for the particular resource - like, moz-newtab-cached://script.js - and check that the hash matches the expectation. If not, blow away all caches, fallback to streaming out the packaged script.
- After retrieving the stream, kick off a DeferredTask that will eventually kick a check to see
- if we need to refresh the cache. Once that fires, check RemoteSettings to see if the hash and/or version has changed.
- If the hash and/or version has changed, download them and stream them into the cache:
- Writing to the cache. When it’s time to write to the cache:
- Recreate the entries for script and styles, and hold onto the new references.
- Write the new hash into prefs.
- Set the metadata to include the hash and version numbers.
- Begin streaming, this puts the entries into WRITING mode.
- Parallel stream scripts and styles into the cache output streams
- If either fail, doom the cache entry. Clear the pref value for the hash. Try again later.
- moz-newtab-cached protocol has one job: get a remote stream from the parent that will either pull from the valid cache entry OR will fallback to the built-in one. Which means that we have a bit of separation here:
- moz-newtab-cached protocol handler is the “read-only” parts here. It just knows how to read from the cache. It does not know how to write to it. It knows how to fall back.
-
The other part is the business around noticing that a newtab loaded, and kicking off the DeferredTask to maybe write an update to the cache. ```
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Resource Links
- Felicia Bacon
- npb hacks on the SpiderMonkey JS engine
- Compiler Compiler live stream
- Try out Mozilla VPN
- Firefox Source Code Documentation
- mozconfigwrapper: A Wrapper to manage different mozconfigs
- MyQOnly: Mike's addon to track your review queues on Mozilla Phabricator
- Mike's Firefox Color Theme
- Firefox Monitor: Stay informed on new data breach of services you're using online
- Create a free Bugzilla account
- Codetribute: Find a good first bug to start contributing on a Mozilla projects (Firefox, Thunderbird, and more). See the above link for creating a Bugzilla account first!
- Nathan Baggs livehacking / reverse engineering
- Alessandro Castellani has been streaming himself livehacking on Thunderbird
- Emilio hacking on Firefox