uBlock Origin 1.9.7b4

Changes

Core code related to static and cosmetic engines has been refactored to take advantage of ES6 Set/Map (related issue: #1070). Polyfilled versions of Set/Map are provided for compatibility with Chromium 37 and less^[1], and for Pale Moon 26 and earlier^[2]. While at it, I also revisited some of the inner-most loops executed at load time to remove other observed overheads in profiling results.

Benchmarks shows that there are good gains to be had in performance and memory efficiency when using ES6 Set/Map. The performance gains are especially true when dealing with collections with a lot of misses, which is typical of the static and cosmetic filtering engines ni uBO.

Following the above refactoring, profiling using Chromium (which makes it easy), I observed:

• Non-selfie case: uBO will roughly load in about half the time, because:
  • Using ES6 Set and Map instead of Object
  • No longer using String.split to split lines into fields = less memory allocations = less work for garbage collector
• Selfie-case: there is a marginal performance improvement at most in boot time -- make sense since a selfie is just a no-parsing-at-all load mechanism regardless of how the data is represented internally.

_{This is default settings + EasyList Germany -- forgot to un-check it before profiling...}

Closed as fixed:

• Automatically lookup site-specific scriptlets
• Howto disable script:inject filters?
• Popups with data:text/html... URL can't be blocked

1. There is a "Enable Experimental JavaScript" flag which can be used to enable ES6 Set/Map for Chromium 31-37. When the polyfilled Set/Map are used for Chromium-based browsers, uBO's memory usage will be higher, as using Object as Set or Map is less efficient memory-wise (though still fast).
2. For Pale Moon 26 and less, Set/Map iterators are not ES6-compatible.