Some improvements to util.HashSet and HashMap #9865
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Allow to record total sizes of collections on which some selected operation is performed. # Conflicts: # compiler/src/dotty/tools/dotc/transform/Instrumentation.scala
See scala#9748 for why this is necessary
When tranisitioning from dense to hashing, we grow the table more than usual since otherwise we'd have to grow it again at the very next addEntry. The condition for this was wrong for HashMaps.
Make criterion when to fill a hole in a HashMap or HashSet remove more robust. The old criterion relied on fill factor always being less than 0.5. The new criterion works for arbitrary fill factors.
The code was taken from scala.collection.mutable.AnyRefMap
odersky
force-pushed
the
fix-sets-maps
branch
from
f9b0ab4 to
daf6db7
Compare
|
test performance please |
|
performance test scheduled: 2 job(s) in queue, 1 running. |
|
Performance test finished successfully: Visit http://dotty-bench.epfl.ch/9865/ to see the changes. Benchmarks is based on merging with master (85d1322) |
liufengyun
approved these changes
Sep 25, 2020
| @@ -156,7 +158,7 @@ abstract class GenericHashMap[Key, Value] | |||
| protected def growTable(): Unit = | |||
| val oldTable = table | |||
| val newLength = | |||
| if oldTable.length == DenseLimit then DenseLimit * 2 * roundToPower(capacityMultiple) | |||
| if table.length == DenseLimit * 2 then table.length * roundToPower(capacityMultiple) | |||
There was a problem hiding this comment.
I don't quite understand why we need the if here, instead of simply growing the table, since all calls to growTable is guarded by if used > limit. Is it to just create a larger array at the size DenseLimit * 2 (instead of simply doubling the size)?
Meanwhile, if we change the code here, do we need similar changes in HashSet.growTable?
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
No description provided.