perf: skip dedup map in mapNodes for single-node selections#550
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LGTM but while we're adding this, let's handle len(nodes) == 0 too. |
mapNodes always allocated a map[*html.Node]bool for deduplication, even when called with a single source node where duplicates cannot arise. Short-circuit to return the callback result directly when len(nodes)==1. Also add a special case for when there are zero nodes. This benefits all traversal methods (Find, Children, Parent, Next, Prev, etc.) when operating on a single-node selection, which is the common case after First(), Eq(), or directly on a Document. name old ns/op new ns/op delta Find-8 23200 14200 -38.8% name old B/op new B/op delta Find-8 4632 1496 -67.7% name old allocs new allocs delta Find-8 27 13 -51.9%
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Sure |
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mapNodes always allocated a map[*html.Node]bool for deduplication, even when called with a single source node where duplicates cannot arise. Short-circuit to return the callback result directly when len(nodes)==1.
This benefits all traversal methods (Find, Children, Parent, Next, Prev, etc.) when operating on a single-node selection, which is the common case after First(), Eq(), or directly on a Document.
name old ns/op new ns/op delta
Find-8 23200 14200 -38.8%
name old B/op new B/op delta
Find-8 4632 1496 -67.7%
name old allocs new allocs delta
Find-8 27 13 -51.9%