perf: choose package with fewest versions matching (30x speedup) #32
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| .potential_packages() | ||
| .next() | ||
| .map(|(p, all_terms)| (p.clone(), Term::intersect_all(all_terms.iter()))) | ||
| .map(|(p, all_terms)| (p, Term::intersect_all(all_terms.iter()))) |
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This looks like a very pricey thing to do if we effectively iterate over all potential packages. In such case, it would probably be worth keeping in memory not a Vec of derivations but their intersections directly. I haven't reread the code but I think we may never need individual derivations for anything. Every usage we have of Memory could be as efficient or more if we actually had the intersection directly.
To be checked
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Yes, That is definitely worth looking into! But with this already being 30x it is hard to tell based on this benchmark. It seams to worth committing now and evaluating that again when we have a new benchmark.
Did you mean 3x speed up then? XD |
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No, sorry typo. I ment 0.006. 😄 |
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All good to me! If that's ok with @aleksator too?, let's merge
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I've added a small doc change to the |
This adds the heuristic that is described in the comment. This is the heuristic asked for in #20, but there may be even better ones to try. Unfortunately, it is hard to tell with the existing benchmark as even this makes the benchmark fly. For me the benchmark 0.175 sec -> 0.006 sec!