Trait ph::fmph::goindexing::GroupSize

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pub trait GroupSize: Sized + Mul<usize, Output = usize> + Copy + Into<u8> + TryFrom<u8, Error = &'static str> {
    // Provided methods
    fn validate(&self) -> Result<Self, &'static str> { ... }
    fn hash_to_group(&self, hash: u32) -> u8 { ... }
    fn in_group_index(&self, hash: u64, group_seed: u16) -> u8 { ... }
    fn bit_index_for_seed(
        &self,
        hash: u64,
        group_seed: u16,
        group: u64
    ) -> usize { ... }
    fn level_size_groups_segments(
        &self,
        desired_total_size: usize
    ) -> (usize, usize) { ... }
    fn copy_group_if_better<CB>(
        &self,
        dst: &mut [u64],
        src: &[u64],
        group_index: usize,
        callback: CB
    )
       where CB: FnOnce() { ... }
    fn write_size_bytes(&self) -> usize { ... }
    fn write(&self, output: &mut dyn Write) -> Result<()> { ... }
    fn read(input: &mut dyn Read) -> Result<Self> { ... }
}

Expand description

Implementations of GroupSize represent group size in fingerprinting-based minimal perfect hashing with group optimization.

Provided Methods§

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fn validate(&self) -> Result<Self, &'static str>

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fn hash_to_group(&self, hash: u32) -> u8

Returns hash modulo self.

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fn in_group_index(&self, hash: u64, group_seed: u16) -> u8

Returns index in the group with given seed group_seed using hasher which must be modified earlier by group_nr function.

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fn bit_index_for_seed(&self, hash: u64, group_seed: u16, group: u64) -> usize

Returns bit index inside the group with number group and seed group_seed, assigned to the key hashed by the hasher.

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fn level_size_groups_segments( &self, desired_total_size: usize ) -> (usize, usize)

Returns number of groups and 64-bit segments for given desired_total_size.

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fn copy_group_if_better<CB>( &self, dst: &mut [u64], src: &[u64], group_index: usize, callback: CB )
where CB: FnOnce(),

Returns number of ones in the group. If group with given index has more ones in dst than in src, then copy it from src to dst and call callback.

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