The Joy of Coding: Episode Guide

Volunteer-driven episode guide for The Joy of Coding

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Episode 431: Feb 25th, 2026

Links

• Watch this episode on Air Mozilla
• Joplin Agenda

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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• Try out Mozilla VPN
• How mconley uses Mercurial
• Fission - Read more about it
• mozconfigwrapper - A Wrapper to keep different mozconfigs
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  • First, Create a Mozilla Bugzilla account.