Searcher: reduce allocations for chunk matches
Created by: camdencheek
While investigating performance of searcher, I noticed we're doing quite a few extra allocations. Each commit is self-contained with a description of the change and showed an improvement in the benchmarks. The benchmark stats below are compared to main. Not a huge win for timings, but massive wins for allocations, which might become more important for timings on a more memory-constrained system.
❯ benchstat -alpha 0.1 /tmp/baseline.txt /tmp/ranges_slices.txt
name old time/op new time/op delta
SearchRegex_large_fixed-10 6.32ms ± 2% 6.18ms ± 0% -2.06% (p=0.008 n=5+5)
SearchRegex_rare_fixed-10 7.96ms ± 1% 7.71ms ± 1% -3.03% (p=0.008 n=5+5)
SearchRegex_large_fixed_casesensitive-10 4.03ms ± 0% 3.93ms ± 1% -2.50% (p=0.008 n=5+5)
SearchRegex_large_re_dotstar-10 235ms ± 1% 218ms ± 1% -7.19% (p=0.008 n=5+5)
SearchRegex_large_re_common-10 6.08ms ± 1% 5.91ms ± 1% -2.82% (p=0.008 n=5+5)
SearchRegex_large_re_anchor-10 69.9ms ± 2% 69.6ms ± 1% ~ (p=0.690 n=5+5)
SearchRegex_large_path/path_only-10 304µs ± 0% 305µs ± 1% ~ (p=0.548 n=5+5)
SearchRegex_large_path/content_only-10 6.92ms ± 2% 6.85ms ± 1% ~ (p=0.151 n=5+5)
SearchRegex_large_path/both_path_and_content-10 7.01ms ± 2% 6.87ms ± 1% -1.92% (p=0.056 n=5+5)
SearchRegex_small_fixed-10 134µs ± 0% 133µs ± 0% -1.10% (p=0.008 n=5+5)
SearchRegex_small_fixed_casesensitive-10 87.5µs ± 0% 78.5µs ± 7% -10.28% (p=0.008 n=5+5)
SearchRegex_small_re_dotstar-10 2.28ms ± 1% 2.27ms ± 1% ~ (p=0.690 n=5+5)
SearchRegex_small_re_common-10 90.7µs ± 0% 87.9µs ± 0% -3.05% (p=0.016 n=4+5)
SearchRegex_small_re_anchor-10 769µs ± 1% 770µs ± 2% ~ (p=0.841 n=5+5)
name old alloc/op new alloc/op delta
SearchRegex_large_fixed-10 15.8MB ± 0% 15.7MB ± 0% -0.90% (p=0.008 n=5+5)
SearchRegex_rare_fixed-10 15.9MB ± 0% 15.7MB ± 0% -0.95% (p=0.008 n=5+5)
SearchRegex_large_fixed_casesensitive-10 167kB ± 0% 10kB ± 0% -94.06% (p=0.008 n=5+5)
SearchRegex_large_re_dotstar-10 685MB ± 0% 570MB ± 0% -16.76% (p=0.008 n=5+5)
SearchRegex_large_re_common-10 7.74MB ± 0% 6.40MB ± 0% -17.31% (p=0.008 n=5+5)
SearchRegex_large_re_anchor-10 5.01MB ± 0% 4.27MB ± 0% -14.79% (p=0.008 n=5+5)
SearchRegex_large_path/path_only-10 1.03kB ± 0% 1.03kB ± 0% ~ (all equal)
SearchRegex_large_path/content_only-10 219kB ± 1% 51kB ± 0% -76.90% (p=0.008 n=5+5)
SearchRegex_large_path/both_path_and_content-10 219kB ± 0% 51kB ± 0% -76.93% (p=0.008 n=5+5)
SearchRegex_small_fixed-10 365kB ± 1% 361kB ± 1% -1.02% (p=0.008 n=5+5)
SearchRegex_small_fixed_casesensitive-10 6.46kB ± 0% 4.71kB ± 0% -27.02% (p=0.008 n=5+5)
SearchRegex_small_re_dotstar-10 4.52MB ± 0% 3.75MB ± 0% -16.95% (p=0.008 n=5+5)
SearchRegex_small_re_common-10 44.7kB ± 0% 38.7kB ± 0% -13.36% (p=0.008 n=5+5)
SearchRegex_small_re_anchor-10 19.8kB ± 0% 18.3kB ± 1% -7.34% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
SearchRegex_large_fixed-10 6.63k ± 0% 0.19k ± 1% -97.17% (p=0.008 n=5+5)
SearchRegex_rare_fixed-10 7.09k ± 0% 0.49k ± 0% -93.08% (p=0.008 n=5+5)
SearchRegex_large_fixed_casesensitive-10 6.59k ± 0% 0.14k ± 0% -97.91% (p=0.008 n=5+5)
SearchRegex_large_re_dotstar-10 6.13M ± 0% 4.51M ± 0% -26.52% (p=0.008 n=5+5)
SearchRegex_large_re_common-10 74.8k ± 0% 50.6k ± 0% -32.32% (p=0.008 n=5+5)
SearchRegex_large_re_anchor-10 54.5k ± 0% 37.9k ± 0% -30.42% (p=0.008 n=5+5)
SearchRegex_large_path/path_only-10 20.0 ± 0% 20.0 ± 0% ~ (all equal)
SearchRegex_large_path/content_only-10 7.03k ± 0% 0.46k ± 0% -93.43% (p=0.008 n=5+5)
SearchRegex_large_path/both_path_and_content-10 7.03k ± 0% 0.46k ± 0% -93.43% (p=0.008 n=5+5)
SearchRegex_small_fixed-10 154 ± 0% 82 ± 0% -46.75% (p=0.008 n=5+5)
SearchRegex_small_fixed_casesensitive-10 146 ± 0% 74 ± 0% -49.32% (p=0.008 n=5+5)
SearchRegex_small_re_dotstar-10 40.5k ± 0% 29.6k ± 0% -26.81% (p=0.008 n=5+5)
SearchRegex_small_re_common-10 537 ± 0% 387 ± 0% -27.93% (p=0.008 n=5+5)
SearchRegex_small_re_anchor-10 296 ± 0% 235 ± 0% -20.61% (p=0.008 n=5+5)
Test plan
Existing unit tests + benchmarks.