ph 0.11.0

The library of data structures based on perfect hashing.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196

use dyn_size_of::GetSize;
use voracious_radix_sort::RadixSort;

use crate::{phast::{builder::{build_mt, build_st, BuildConf}, conf::Conf, evaluator::BucketToActivateEvaluator, function::SeedEx, Params, SeedChooser, SeedOnly, WINDOW_SIZE}, seeds::SeedSize};
use std::hash::{BuildHasher, Hash, RandomState};

/// Map-or-bump function that assigns different numbers to some keys and `None` to other.
/// 
/// Can be used with any seed chooser (which specify a particular PHast variant):
/// [`ShiftOnlyWrapped`], [`ShiftSeedWrapped`], [`SeedOnly`], [`SeedOnlyK`].
/// 
/// See:
/// Piotr Beling, Peter Sanders, *PHast - Perfect Hashing made fast*, 2025, <https://arxiv.org/abs/2504.17918>
pub struct Partial<SS, SC = SeedOnly, S = RandomState> where SS: SeedSize {
    seeds: SeedEx<SS::VecElement>,
    hasher: S,
    seed_chooser: SC,
    seed_size: SS,
}

impl<SC, SS: SeedSize, S> GetSize for Partial<SS, SC, S> {
    fn size_bytes_dyn(&self) -> usize { self.seeds.size_bytes_dyn() }
    fn size_bytes_content_dyn(&self) -> usize { self.seeds.size_bytes_content_dyn() }
    const USES_DYN_MEM: bool = true;
}

impl<SS: SeedSize, SC: SeedChooser> Partial<SS, SC, ()> {
    pub fn with_hashes_bps_conf_sc_be_u<'k, BE>(hashes: &'k mut [u64], seed_size: SS, conf: Conf, seed_chooser: SC, bucket_evaluator: BE) -> (Self, usize)
        where BE: BucketToActivateEvaluator
    {
        let (f, build_conf) = Self::build_st(hashes, seed_size, conf, (), seed_chooser, bucket_evaluator);
        let unassigned = build_conf.unassigned_len(&f.seeds.seeds);
        (f, unassigned)
    }

    pub fn with_hashes_bps_conf_bs_threads_sc_be_u<'k, BE>(hashes: &'k mut [u64], seed_size: SS, conf: Conf, threads_num: usize, seed_chooser: SC, bucket_evaluator: BE) -> (Self, usize)
        where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send
    {
        let (f, build_conf) = Self::build_mt(hashes, seed_size, conf, threads_num, (), seed_chooser, bucket_evaluator);
        let unassigned = build_conf.unassigned_len(&f.seeds.seeds);
        (f, unassigned)
    }


    pub fn with_hashes_bps_conf_sc_be<'k, BE>(hashes: &'k mut [u64], seed_size: SS, conf: Conf, seed_chooser: SC, bucket_evaluator: BE) -> Self
        where BE: BucketToActivateEvaluator
    {
        Self::build_st(hashes, seed_size, conf, (), seed_chooser, bucket_evaluator).0
    }

    pub fn with_hashes_bps_conf_bs_threads_sc_be<'k, BE>(hashes: &'k mut [u64], seed_size: SS, conf: Conf, threads_num: usize, seed_chooser: SC, bucket_evaluator: BE) -> Self
        where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send
    {
        Self::build_mt(hashes, seed_size, conf, threads_num, (), seed_chooser, bucket_evaluator).0
    }


    pub fn with_hashes_p_sc_be_u<'k, BE>(hashes: &'k mut [u64], params: &Params<SS>, seed_chooser: SC, bucket_evaluator: BE) -> (Self, usize)
        where BE: BucketToActivateEvaluator
    {
        let conf = seed_chooser.conf_for_minimal_p(hashes.len(), params);
        Self::with_hashes_bps_conf_sc_be_u(hashes, params.seed_size, conf, seed_chooser, bucket_evaluator)
    }

    pub fn with_hashes_p_threads_sc_be_u<'k, BE>(hashes: &'k mut [u64], params: &Params<SS>, threads_num: usize, seed_chooser: SC, bucket_evaluator: BE) -> (Self, usize)
        where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send
    {
        let conf = seed_chooser.conf_for_minimal_p(hashes.len(), params);
        Self::with_hashes_bps_conf_bs_threads_sc_be_u(hashes, params.seed_size, conf, threads_num, seed_chooser, bucket_evaluator)
    }


    pub fn with_hashes_p_sc_be<'k, BE>(hashes: &'k mut [u64], params: &Params<SS>, seed_chooser: SC, bucket_evaluator: BE) -> Self
        where BE: BucketToActivateEvaluator
    {
        let conf = seed_chooser.conf_for_minimal_p(hashes.len(), params);
        Self::with_hashes_bps_conf_sc_be(hashes, params.seed_size, conf, seed_chooser, bucket_evaluator)
    }

    pub fn with_hashes_p_threads_sc_be<'k, BE>(hashes: &'k mut [u64], params: &Params<SS>, threads_num: usize, seed_chooser: SC, bucket_evaluator: BE) -> Self
        where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send
    {
        let conf = seed_chooser.conf_for_minimal_p(hashes.len(), params);
        Self::with_hashes_bps_conf_bs_threads_sc_be(hashes, params.seed_size, conf, threads_num, seed_chooser, bucket_evaluator)
    }


    pub fn with_hashes_p_sc_u<'k, BE>(hashes: &'k mut [u64], params: &Params<SS>, seed_chooser: SC) -> (Self, usize)
        where BE: BucketToActivateEvaluator
    {
        let conf = seed_chooser.conf_for_minimal_p(hashes.len(), params);
        let bucket_evaluator = seed_chooser.bucket_evaluator(params.bits_per_seed(), conf.slice_len());
        Self::with_hashes_bps_conf_sc_be_u(hashes, params.seed_size, conf, seed_chooser, bucket_evaluator)
    }

    pub fn with_hashes_p_threads_sc_u<'k, BE>(hashes: &'k mut [u64], params: &Params<SS>, threads_num: usize, seed_chooser: SC) -> (Self, usize)
        where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send
    {
        let conf = seed_chooser.conf_for_minimal_p(hashes.len(), params);
        let bucket_evaluator = seed_chooser.bucket_evaluator(params.bits_per_seed(), conf.slice_len());
        Self::with_hashes_bps_conf_bs_threads_sc_be_u(hashes, params.seed_size, conf, threads_num, seed_chooser, bucket_evaluator)
    }


    pub fn with_hashes_p_sc<'k>(hashes: &'k mut [u64], params: &Params<SS>, seed_chooser: SC) -> Self
    {
        let conf = seed_chooser.conf_for_minimal_p(hashes.len(), params);
        let bucket_evaluator = seed_chooser.bucket_evaluator(params.bits_per_seed(), conf.slice_len());
        Self::with_hashes_bps_conf_sc_be(hashes, params.seed_size, conf, seed_chooser, bucket_evaluator)
    }

    pub fn with_hashes_p_threads_sc<'k>(hashes: &'k mut [u64], params: &Params<SS>, threads_num: usize, seed_chooser: SC) -> Self
        where SC: Sync
    {
        let conf = seed_chooser.conf_for_minimal_p(hashes.len(), params);
        let bucket_evaluator = seed_chooser.bucket_evaluator(params.bits_per_seed(), conf.slice_len());
        Self::with_hashes_bps_conf_bs_threads_sc_be(hashes, params.seed_size, conf, threads_num, seed_chooser, bucket_evaluator)
    }
}



impl<SS: SeedSize, SC: SeedChooser, S> Partial<SS, SC, S> {
    /// Returns value assigned to the given key hash or `None`.
    #[inline(always)]
    pub fn get_for_hash(&self, key_hash: u64) -> Option<usize> {
        let seed = unsafe { self.seeds.seed_for(self.seed_size, key_hash) };
        (seed != 0).then(|| self.seed_chooser.f(key_hash, seed, &self.seeds.conf))
    }

    fn build_st<'k, BE>(hashes: &'k mut [u64], seed_size: SS, conf: Conf, hasher: S, seed_chooser: SC, bucket_evaluator: BE)
     -> (Self, BuildConf<'k, BE, SS, SC>)
        where BE: BucketToActivateEvaluator
    {
        hashes.voracious_sort();
        let (seeds, build_conf) = build_st(hashes, conf, seed_size, bucket_evaluator, seed_chooser);
        (Self {
            seeds: SeedEx{ seeds, conf },
            hasher,
            seed_chooser,
            seed_size
        }, build_conf)
    }

    fn build_mt<'k, BE>(hashes: &'k mut [u64], seed_size: SS, conf: Conf, threads_num: usize, hasher: S, seed_chooser: SC, bucket_evaluator: BE)
     -> (Self, BuildConf<'k, BE, SS, SC>)
        where BE: BucketToActivateEvaluator + Sync, SC: Sync, BE::Value: Send
    {
        if threads_num == 1 { return Self::build_st(hashes, seed_size, conf, hasher, seed_chooser, bucket_evaluator); }
        hashes.voracious_mt_sort(threads_num);
        let (seeds, build_conf) = build_mt(hashes, conf, seed_size, WINDOW_SIZE, bucket_evaluator, seed_chooser, threads_num);
        (Self {
            seeds: SeedEx{ seeds, conf },
            hasher,
            seed_chooser,
            seed_size,
        }, build_conf)
    }
}

impl<SS: SeedSize, SC: SeedChooser, S> Partial<SS, SC, S> {
    /// Returns output range of minimal (perfect or k-perfect) function for given number of keys,
    /// i.e. 1 + maximum value that minimal function can return.
    #[inline(always)] pub fn minimal_output_range(&self, num_of_keys: u32) -> usize {
        self.seed_chooser.minimal_output_range(num_of_keys as usize)
    }

    /// Returns output range of `self`, i.e. 1 + maximum value that `self` can return.
    pub fn output_range(&self) -> usize {
        self.seeds.conf.output_range(self.seed_chooser, self.seed_size.into())
    }
}

impl<SS: SeedSize, SC: SeedChooser, S: BuildHasher> Partial<SS, SC, S> {
    /// Returns value assigned to the given `key` or `None`.
    /// 
    /// The returned value is in the range from `0` (inclusive) to the number of elements in the input key collection (exclusive).
    /// `key` must come from the input key collection given during construction.
    #[inline(always)]
    pub fn get<K>(&self, key: &K) -> Option<usize> where K: Hash + ?Sized {
        self.get_for_hash(self.hasher.hash_one(key))
    }

    /// Returns [`Partial`] function and number of keys with unassigned values for given `keys`,
    /// using a single thread and given parameters.
    pub fn with_keys_p_hash_sc_be_u<'k, K, BE>(keys: impl Iterator<Item = K>, params: &Params<SS>, hasher: S, seed_chooser: SC, bucket_evaluator: BE)
     -> (Self, usize)
        where K: Hash, BE: BucketToActivateEvaluator
    {
        let mut hashes: Box<[_]> = keys.map(|k| hasher.hash_one(k)).collect();
        let conf = seed_chooser.conf_for_minimal_p(hashes.len(), params);
        let (f, build_conf) = Self::build_st(&mut hashes, params.seed_size, conf, hasher, seed_chooser, bucket_evaluator);
        let unassigned = build_conf.unassigned_len(&f.seeds.seeds);
        (f, unassigned)
    }
}