Optimize array_combine with a fast path and fix memory leak #19640
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This commit introduces a "fast path" optimization for the `array_combine()` function to improve performance for the common case where both input arrays are packed (simple, 0-indexed lists without holes). Instead of using generic iterators, the fast path uses a direct `for` loop to access array elements, significantly reducing overhead. Additionally, a memory leak in the original implementation was identified and fixed. The generic code path was incorrectly incrementing the reference count of values in the newly created array, which also caused a performance degradation due to memory management overhead. This has been corrected in the fallback path. Benchmark results show a significant performance improvement: - Packed indexed arrays are ~70% faster due to the new fast path. - Associative arrays are ~65% faster due to the memory leak fix.
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This commit introduces a "fast path" optimization for the
array_combine()function to improve performance for the common case where both input arrays are packed (simple, 0-indexed lists without holes). Instead of using generic iterators, the fast path uses a directforloop to access array elements, significantly reducing overhead.Additionally, a memory leak in the original implementation was identified and fixed. The generic code path was incorrectly incrementing the reference count of values in the newly created array, which also caused a performance degradation due to memory management overhead. This has been corrected in the fallback path.
Benchmark results show a significant performance improvement: