Merge cockroachdb#44617

44617: util/interval/generic: avoid new allocations in btree benchmarks r=nvanbenschoten a=nvanbenschoten The generic template for interval btree makes an attempt to work with both value and pointer parameterized types. To facilitate this option in tests, it used reflection to create new instances of the item type. This reflection was preventing allocations of the item type from being inlined and avoided by escape analysis, which was skewing benchmarks. This commit fixes this by avoiding the reflection and instead adding a constructor to the contract of the parameterized type. This is cleaner and allows the allocations to be avoided in these benchmarks. Here's the new `benchdiff` output of the latch manager's btree from before cockroachdb#43850 to after this change: [benchdiff sheet](https://docs.google.com/spreadsheets/d/1ZxtPPSWV0z76msCiwIyqL0xnUQF530ZwnbnfrvEzNAE/edit#gid=4). Co-authored-by: Nathan VanBenschoten <[email protected]>
tbg · Feb 3, 2020 · e49530d · e49530d
2 parents 1347bd4 + f80ed60
commit e49530d
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Showing 6 changed files with 112 additions and 139 deletions.
diff --git a/pkg/storage/spanlatch/latch_interval_btree_test.go b/pkg/storage/spanlatch/latch_interval_btree_test.go
diff --git a/pkg/storage/spanlatch/manager.go b/pkg/storage/spanlatch/manager.go
@@ -101,6 +101,7 @@ func (la *latch) ID() uint64         { return la.id }
 func (la *latch) Key() []byte        { return la.span.Key }
 func (la *latch) EndKey() []byte     { return la.span.EndKey }
 func (la *latch) String() string     { return fmt.Sprintf("%s@%s", la.span, la.ts) }
+func (la *latch) New() *latch        { return new(latch) }
 func (la *latch) SetID(v uint64)     { la.id = v }
 func (la *latch) SetKey(v []byte)    { la.span.Key = v }
 func (la *latch) SetEndKey(v []byte) { la.span.EndKey = v }