perf: use global prefix slices to avoid allocations#298
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Summary of Changes
Hello @tzdybal, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!
This pull request implements a performance optimization aimed at reducing memory allocations within the hashing process. By introducing global, pre-allocated byte slices for node and leaf prefixes, the change eliminates the need for dynamic allocation of single-byte slices every time a prefix is used for hashing. This results in a substantial decrease in the number of allocations per operation, as evidenced by benchmark results showing over a 24% reduction in allocs/op, without negatively impacting execution time.
Highlights
- Memory Optimization: Introduced global byte slices for
LeafPrefixandNodePrefixto eliminate repeated small allocations. - Code Refactoring: Replaced direct
[]byte{...}creation with references to the new global slices inHashLeafandHashNodefunctions. - Performance Improvement: Achieved a significant reduction in allocations per operation (over 24%) as demonstrated by benchmark results, with negligible impact on time per operation.
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Code Review
This pull request introduces a solid performance optimization by pre-allocating global slices for leaf and node prefixes. This change effectively reduces memory allocations during hashing operations, as demonstrated by the provided benchmark results which show a ~24% reduction in allocs/op. The implementation is straightforward, correct, and follows common Go optimization patterns. Excellent work!
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We should release this soon to include it in the performance work. |
Overview
This is a very low-hanging-fruit optimization that significantly (by over 24%) reduces number of allocations (in benchmarks). Before the change, every time node/leaf prefix is used for hashing, small slice was dynamically allocated just to pass single byte. Keeping those slices as global values ensures they are allocated exactly once.
Benchmark results: