add simd for faster magic number searches#72
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This implements SIMD based vectorized magic number search with SSE4.2, AVX2 and AVX512. Signed-off-by: Thomas Jungblut <[email protected]>
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That PR adds a magic number search based on AVX2. This reduces the sstable disk index search time from:
to
Not an insane improvement, but I think we can use that to very quickly read the recordio file to determine the index offsets. Which in turn allows to binary search/map lookup without additional seeking.
The SSE4.2 version can read 10-12gb/s to find the magic numbers (up from 3gb/s with simple looping), so this allows us to compute the lookup table very quickly.