fullcodec_plonk/plonkup/table/
witness_table.rs

1// This Source Code Form is subject to the terms of the Mozilla Public
2// License, v. 2.0. If a copy of the MPL was not distributed with this
3// file, You can obtain one at http://mozilla.org/MPL/2.0/.
4//
5// Copyright (c) DUSK NETWORK. All rights reserved.
6
7use crate::error::Error;
8use crate::plonkup::LookupTable;
9use crate::plonkup::MultiSet;
10use dusk_bls12_381::BlsScalar;
11
12/// This witness table contains quieries
13/// to a lookup table for lookup gates
14/// This table is of arity 3.
15#[derive(Clone, Eq, PartialEq, Debug)]
16pub struct WitnessTable {
17    /// This column represents the
18    /// first values inside the lookup
19    /// table. At gate checks, this
20    /// can be regarded as the first
21    /// wire
22    pub f_1: MultiSet,
23
24    /// This column represents the
25    /// first values inside the lookup
26    /// table. At gate checks, this
27    /// can be regarded as the second
28    /// wire
29    pub f_2: MultiSet,
30
31    /// This column represents the
32    /// first values inside the lookup
33    /// table. At gate checks, this
34    /// can be regarded as the third
35    /// wire
36    pub f_3: MultiSet,
37
38    /// This column represents the
39    /// first values inside the lookup
40    /// table. At gate checks, this
41    /// can be regarded as the fourth
42    /// wire
43    pub f_4: MultiSet,
44}
45
46impl Default for WitnessTable {
47    fn default() -> Self {
48        WitnessTable::new()
49    }
50}
51
52impl WitnessTable {
53    /// Initialses empty witness table of arity 4
54    pub fn new() -> Self {
55        WitnessTable {
56            f_1: MultiSet::new(),
57            f_2: MultiSet::new(),
58            f_3: MultiSet::new(),
59            f_4: MultiSet::new(),
60        }
61    }
62    /// This allows the witness table to be filled directly without
63    /// taking any vaules, or the the results, from the lookup table.
64    /// If the values do no exists in the lookup table, then the proof
65    /// will fail when witness and preprocessed tables are concatenated.
66    pub fn from_wire_values(
67        &mut self,
68        left_wire_val: BlsScalar,
69        right_wire_val: BlsScalar,
70        output_wire_val: BlsScalar,
71        fourth_wire_val: BlsScalar,
72    ) {
73        self.f_1.push(left_wire_val);
74        self.f_2.push(right_wire_val);
75        self.f_3.push(output_wire_val);
76        self.f_4.push(fourth_wire_val);
77    }
78
79    /// Attempts to look up a value from a lookup table. If successful, all four
80    /// elements are pushed to their respective multisets.
81    pub fn value_from_table(
82        &mut self,
83        lookup_table: &LookupTable,
84        left_wire_val: BlsScalar,
85        right_wire_val: BlsScalar,
86        fourth_wire_val: BlsScalar,
87    ) -> Result<(), Error> {
88        let output_wire_val = lookup_table.lookup(
89            left_wire_val,
90            right_wire_val,
91            fourth_wire_val,
92        )?;
93        self.f_1.push(left_wire_val);
94        self.f_2.push(right_wire_val);
95        self.f_3.push(output_wire_val);
96        self.f_4.push(fourth_wire_val);
97        Ok(())
98    }
99}
100#[cfg(test)]
101mod test {
102    use super::*;
103    use crate::plonkup::LookupTable;
104
105    #[test]
106    fn test_lookup() {
107        // Build empty lookup tables
108        let mut lookup_table = LookupTable::new();
109
110        // Add a consecutive set of tables, with
111        // XOR operationd and addition operations
112        lookup_table.insert_multi_xor(0, 4);
113        lookup_table.insert_multi_add(2, 3);
114
115        // Build empty witness table
116        let mut f = WitnessTable::new();
117
118        // Check for output of wires within lookup table and
119        // if they exist input them to the witness table
120        assert!(f
121            .value_from_table(
122                &lookup_table,
123                BlsScalar::from(2),
124                BlsScalar::from(3),
125                -BlsScalar::one()
126            )
127            .is_ok());
128        assert!(f
129            .value_from_table(
130                &lookup_table,
131                BlsScalar::from(4),
132                BlsScalar::from(6),
133                BlsScalar::zero()
134            )
135            .is_ok());
136
137        // Check that values not contained in the lookup table
138        // do not get added to the witness table
139        assert!(f
140            .value_from_table(
141                &lookup_table,
142                BlsScalar::from(22),
143                BlsScalar::from(1),
144                -BlsScalar::one()
145            )
146            .is_err());
147        assert!(f
148            .value_from_table(
149                &lookup_table,
150                BlsScalar::from(0),
151                BlsScalar::from(1),
152                BlsScalar::zero()
153            )
154            .is_err());
155    }
156}
fullcodec_plonk/plonkup/table/witness_table.rs

fullcodec_plonk/plonkup/table/
witness_table.rs
