Reduce ImmutableDictionary allocations in CreateCompilationTrackerMap #70319
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ToddGrun
commented
Oct 10, 2023
ToddGrun
commented
- No need to create a builder if _projectIdToTrackerMap is empty
- No need to create a new ImmutableDictionary if it would end up having the exact same contents as projectIdToTrackerMap
1) No need to create a builder if _projectIdToTrackerMap is empty 2) No need to create a new ImmutableDictionary if it would end up having the exact same contents as projectIdToTrackerMap
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jasonmalinowski
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Oct 10, 2023
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| var newTrackerInfo = ArrayBuilder<KeyValuePair<ProjectId, ICompilationTracker>>.GetInstance(); | ||
| var allReused = true; |
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Are we better off just doing a loop first checking the dependency graph CanReuse() for each of the entries, and if so just bailing entirely? Otherwise here we're still allocating the builder only to throw it away if that case happens.
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From what I've seen, pretty much everything about ImmutableDictionarys are slow, so I figured it was just better to make a single pass through it. The intent here is that the ArrayBuilder won't actually allocate normally, so the only real allocation that will happen is if the ImmutableDictionary really needs to be created.
src/Workspaces/Core/Portable/Workspace/Solution/SolutionState.cs
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