Sort: improve some of the performances#11412
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cakebaker merged 3 commits intouutils:mainfrom Mar 20, 2026
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Expose ICU4X's write_sort_key_utf8_to via a public helper that appends a collation sort key to a caller-supplied buffer. This enables computing sort keys once per line (O(n)) and then comparing cheap byte arrays during sorting, instead of calling compare_utf8 on every comparison.
Add collation_key_buffer (arena) and collation_key_ends (offsets) to LineData and RecycledChunk, with a collation_key() accessor. All sort keys for a chunk are stored in a single Vec<u8> to avoid millions of small heap allocations.
Add a fast_locale_collation path that pre-computes ICU sort keys during line parsing (O(n)), then uses cheap byte-array comparison during sorting (O(n log n)). This replaces per-comparison ICU compare_utf8 calls for the common case of plain `sort` with a UTF-8 locale. With 1M lines and LC_ALL=en_US.UTF-8, this is ~2.6x faster than GNU sort (314ms vs 822ms).
Merging this PR will degrade performance by 45.43%
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i am fine trading memory vs speed :) |
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Closes: #11258