task: performance improvement when fetching digest for target #79
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This changes `bazelSourceFileTargets` from a set of targets to a map of the target name to the target itself; that way we can simply do a lookup of the target name, rather than looping through the set every time we look for this (which is quite a lot, since this happens when trying to get a digest for every single target).
tinder-maxwellelliott
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Jul 25, 2021
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tinder-maxwellelliott
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tinder-maxwellelliott
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Thank you so much for fixing this 😊
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After the change to hash all source files, we noticed a significant performance drop; generating all hashes for two different revisions took upwards of 2 minutes locally, and 6 minutes on our CI machines (which are not that powerful).
I noticed that we were looking for a target name in
bazelSourceFileTargets, but this lookup was a linear one each time, and this method is called for every target we're creating a digest for. Since this set is only used here, I've changed it to a map, so we can simply lookup the target in constant time.This is significantly faster for us, bring down the time to ~10s locally, and ~1.5mins on our CI.