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22 строки
774 B
Markdown
22 строки
774 B
Markdown
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# rustc-hash
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A speedy hash algorithm used within rustc. The hashmap in liballoc by
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default uses SipHash which isn't quite as speedy as we want. In the
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compiler we're not really worried about DOS attempts, so we use a fast
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non-cryptographic hash.
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This is the same as the algorithm used by Firefox -- which is a
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homespun one not based on any widely-known algorithm -- though
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modified to produce 64-bit hash values instead of 32-bit hash
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values. It consistently out-performs an FNV-based hash within rustc
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itself -- the collision rate is similar or slightly worse than FNV,
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but the speed of the hash function itself is much higher because it
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works on up to 8 bytes at a time.
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## Usage
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```
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use rustc_hash::FxHashMap;
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let map: FxHashMap<u32, u32> = FxHashMap::default();
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```
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