dupehell 0.5.5

Synthetic multi-domain dataset generator for record linkage benchmarking
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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347

// DupeHell -- MIT License
//
// Synthetic multi-domain dataset generator for record linkage benchmarking.
// No liability for misuse.

use std::sync::Arc;

use arrow::array::{Array, ArrayRef, StringBuilder};

use crate::rng::Rng;

use super::{MIN_LEN_AGGR, MIN_LEN_EXTREME, MIN_LEN_TYPO, get_chars_into};

/// QWERTY <-> AZERTY key swaps — a `match` over 8 entries beats a
/// `LazyLock<HashMap>` (no hashing, no lazy-init check).
fn qwerty_azerty(c: char) -> Option<char> {
    match c {
        'q' => Some('a'),
        'w' => Some('z'),
        'a' => Some('q'),
        'z' => Some('w'),
        'Q' => Some('A'),
        'W' => Some('Z'),
        'A' => Some('Q'),
        'Z' => Some('W'),
        _ => None,
    }
}

// ── Single-char operations ────────────────────────────────────────

fn op_replace(chars: &mut [char], pos: usize, c: char) {
    if !chars.is_empty() {
        let idx = pos % chars.len();
        chars[idx] = c;
    }
}

fn op_insert(chars: &mut Vec<char>, pos: usize, c: char) {
    let p = if chars.is_empty() {
        0
    } else {
        pos % chars.len()
    };
    chars.insert(p, c);
}

fn op_duplicate(chars: &mut Vec<char>, pos: usize) {
    if chars.len() > 1 {
        let p = pos % chars.len();
        chars.insert(p, chars[p]);
    }
}

fn op_swap(chars: &mut [char], pos: usize) {
    if chars.len() > 1 {
        let p = pos % (chars.len() - 1);
        chars.swap(p, p + 1);
    }
}

fn op_delete_pop(chars: &mut Vec<char>, pos: usize) {
    if chars.len() > 2 {
        chars.remove(pos % chars.len());
    }
}

// ── Aggressive helpers ────────────────────────────────────────────

fn apply_swaps(chars: &mut [char], n_swap: usize, swap_positions: &[usize]) {
    for j in 0..n_swap {
        if chars.len() > 2 && j < swap_positions.len() {
            let p = swap_positions[j] % (chars.len() - 2);
            chars.swap(p, p + 1);
        }
    }
}

fn apply_ops_with_randchar(
    chars: &mut Vec<char>,
    n: usize,
    ops: &[usize],
    positions: &[usize],
    rand_chars: &[char],
) {
    for j in 0..n {
        if j >= ops.len() || j >= positions.len() || j >= rand_chars.len() {
            break;
        }
        let pos = if chars.is_empty() {
            0
        } else {
            positions[j] % chars.len()
        };
        match ops[j] % 4 {
            0 => op_delete_pop(chars, pos),
            1 => op_replace(chars, pos, rand_chars[j]),
            2 => op_insert(chars, pos, rand_chars[j]),
            3 => op_duplicate(chars, pos),
            _ => {}
        }
    }
}

// ── Public noise functions ────────────────────────────────────────

/// Light typo: 1-2 delete/replace/insert ops per string.
pub fn apply_typos_str(arr: &dyn arrow::array::Array, rng: &mut Rng, max_dist: usize) -> ArrayRef {
    use arrow::array::AsArray;
    let src = arr.as_string::<i32>();
    let n = src.len();
    let mut rng2 = rng.fork();

    // Pre-allocate random arrays, flattened to one `Vec` each (n * max_dist)
    // instead of a `Vec<Vec<_>>` (n+1 heap allocations) — row-major order
    // preserves the exact same RNG draw sequence, `base + j` replaces `[i][j]`.
    let n_ops: Vec<usize> = (0..n).map(|_| rng2.next_usize(max_dist) + 1).collect();
    let ops: Vec<usize> = (0..n * max_dist).map(|_| rng2.next_usize(3)).collect();
    let positions: Vec<usize> = (0..n * max_dist).map(|_| rng2.next_usize(30)).collect();
    let rand_chars: Vec<char> = (0..n * max_dist)
        .map(|_| (rng2.next_usize(26) as u8 + 97) as char)
        .collect();

    let mut builder = StringBuilder::with_capacity(n, n * 16);
    let mut chars: Vec<char> = Vec::new();
    let mut str_buf = String::new();
    for (i, &n_op) in n_ops.iter().enumerate() {
        if get_chars_into(src, i, MIN_LEN_TYPO, &mut chars) {
            let base = i * max_dist;
            for j in 0..n_op.min(max_dist) {
                let pos = positions[base + j] % chars.len();
                let op_idx = ops[base + j] % 3;
                match op_idx {
                    0 => op_delete_pop(&mut chars, pos),
                    1 => op_replace(&mut chars, pos, rand_chars[base + j]),
                    2 => op_insert(&mut chars, pos, rand_chars[base + j]),
                    _ => {}
                }
            }
            str_buf.clear();
            str_buf.extend(chars.iter());
            builder.append_value(&str_buf);
        } else if src.is_null(i) {
            builder.append_null();
        } else {
            builder.append_value(src.value(i));
        }
    }
    *rng = rng2;
    Arc::new(builder.finish())
}

/// Aggressive typos: 1-2 swaps + 2-4 typo ops.
pub fn apply_typos_aggressive(arr: &dyn arrow::array::Array, rng: &mut Rng) -> ArrayRef {
    use arrow::array::AsArray;
    let src = arr.as_string::<i32>();
    let n = src.len();
    let mut rng2 = rng.fork();

    let n_swap: Vec<usize> = (0..n).map(|_| rng2.next_usize(2) + 1).collect();
    let swap_pos: Vec<usize> = (0..n * 2).map(|_| rng2.next_usize(28)).collect();
    let n_typo: Vec<usize> = (0..n).map(|_| rng2.next_usize(3) + 2).collect();
    let typo_ops: Vec<usize> = (0..n * 5).map(|_| rng2.next_usize(4)).collect();
    let typo_pos: Vec<usize> = (0..n * 5).map(|_| rng2.next_usize(30)).collect();
    let typo_chars: Vec<char> = (0..n * 5)
        .map(|_| (rng2.next_usize(26) as u8 + 97) as char)
        .collect();

    let mut builder = StringBuilder::with_capacity(n, n * 16);
    let mut chars: Vec<char> = Vec::new();
    let mut str_buf = String::new();
    for i in 0..n {
        if get_chars_into(src, i, MIN_LEN_AGGR, &mut chars) {
            apply_swaps(&mut chars, n_swap[i], &swap_pos[i * 2..i * 2 + 2]);
            apply_ops_with_randchar(
                &mut chars,
                n_typo[i],
                &typo_ops[i * 5..i * 5 + 5],
                &typo_pos[i * 5..i * 5 + 5],
                &typo_chars[i * 5..i * 5 + 5],
            );
            str_buf.clear();
            str_buf.extend(chars.iter());
            builder.append_value(&str_buf);
        } else if src.is_null(i) {
            builder.append_null();
        } else {
            builder.append_value(src.value(i));
        }
    }
    *rng = rng2;
    Arc::new(builder.finish())
}

/// Extreme typos: 4-7 ops from all 5 operation types.
pub fn apply_typos_extreme(arr: &dyn arrow::array::Array, rng: &mut Rng) -> ArrayRef {
    use arrow::array::AsArray;
    let src = arr.as_string::<i32>();
    let n = src.len();
    let mut rng2 = rng.fork();

    let n_ops: Vec<usize> = (0..n).map(|_| rng2.next_usize(4) + 4).collect();
    let ops: Vec<usize> = (0..n * 8).map(|_| rng2.next_usize(5)).collect();
    let positions: Vec<usize> = (0..n * 8).map(|_| rng2.next_usize(30)).collect();
    let rand_chars: Vec<char> = (0..n * 8)
        .map(|_| (rng2.next_usize(26) as u8 + 97) as char)
        .collect();

    let mut builder = StringBuilder::with_capacity(n, n * 16);
    let mut chars: Vec<char> = Vec::new();
    let mut str_buf = String::new();
    for (i, &n_op) in n_ops.iter().enumerate() {
        if get_chars_into(src, i, MIN_LEN_EXTREME, &mut chars) {
            let base = i * 8;
            for j in 0..n_op.min(8) {
                if chars.is_empty() {
                    break;
                }
                let pos = positions[base + j] % chars.len();
                match ops[base + j] % 5 {
                    0 => op_delete_pop(&mut chars, pos),
                    1 => op_replace(&mut chars, pos, rand_chars[base + j]),
                    2 => op_insert(&mut chars, pos, rand_chars[base + j]),
                    3 => op_duplicate(&mut chars, pos),
                    4 => op_swap(&mut chars, pos),
                    _ => {}
                }
            }
            str_buf.clear();
            str_buf.extend(chars.iter());
            builder.append_value(&str_buf);
        } else if src.is_null(i) {
            builder.append_null();
        } else {
            builder.append_value(src.value(i));
        }
    }
    *rng = rng2;
    Arc::new(builder.finish())
}

/// QWERTY → AZERTY substitution.
pub fn apply_qwerty_azerty(arr: &dyn arrow::array::Array, rng: &mut Rng) -> ArrayRef {
    use arrow::array::AsArray;
    let src = arr.as_string::<i32>();
    let n = src.len();
    let mut rng2 = rng.fork();

    let n_ops: Vec<usize> = (0..n).map(|_| rng2.next_usize(2) + 1).collect();
    let positions: Vec<usize> = (0..n * 2).map(|_| rng2.next_usize(30)).collect();

    let mut builder = StringBuilder::with_capacity(n, n * 16);
    let mut chars: Vec<char> = Vec::new();
    let mut str_buf = String::new();
    for i in 0..n {
        if get_chars_into(src, i, MIN_LEN_TYPO, &mut chars) {
            for &p in positions[i * 2..i * 2 + 2].iter().take(n_ops[i].min(2)) {
                let pos = p % chars.len();
                if let Some(replacement) = qwerty_azerty(chars[pos]) {
                    chars[pos] = replacement;
                }
            }
            str_buf.clear();
            str_buf.extend(chars.iter());
            builder.append_value(&str_buf);
        } else if src.is_null(i) {
            builder.append_null();
        } else {
            builder.append_value(src.value(i));
        }
    }
    *rng = rng2;
    Arc::new(builder.finish())
}

#[cfg(test)]
mod tests {
    use super::*;
    use arrow::array::{Array, AsArray, StringArray};

    fn test_rng() -> Rng {
        Rng::new(42)
    }

    fn make_arr(vals: &[&str]) -> ArrayRef {
        Arc::new(StringArray::from(vals.to_vec()))
    }

    #[test]
    fn test_typos_str() {
        let arr = make_arr(&["hello", "world", "abc"]);
        let mut rng = test_rng();
        let result = apply_typos_str(&*arr, &mut rng, 2);
        let s = result.as_string::<i32>();
        assert_eq!(s.len(), 3);
        assert!(!s.value(0).is_empty());
    }

    #[test]
    fn test_typos_aggressive() {
        let arr = make_arr(&["hello", "world", "test"]);
        let mut rng = test_rng();
        let result = apply_typos_aggressive(&*arr, &mut rng);
        assert_eq!(result.len(), 3);
        assert!(!result.as_string::<i32>().value(0).is_empty());
    }

    #[test]
    fn test_typos_extreme() {
        let arr = make_arr(&["hello world", "testing", "abcdefgh"]);
        let mut rng = test_rng();
        let result = apply_typos_extreme(&*arr, &mut rng);
        assert_eq!(result.len(), 3);
    }

    #[test]
    fn test_qwerty_azerty() {
        let arr = make_arr(&["quick", "welcome", "azerty"]);
        let mut rng = test_rng();
        let result = apply_qwerty_azerty(&*arr, &mut rng);
        assert_eq!(result.len(), 3);
    }

    #[test]
    fn test_typos_deterministic() {
        let arr = make_arr(&["hello", "world"]);
        let a = apply_typos_str(&*arr, &mut Rng::new(42), 2);
        let b = apply_typos_str(&*arr, &mut Rng::new(42), 2);
        let sa = a.as_string::<i32>();
        let sb = b.as_string::<i32>();
        assert_eq!(sa.value(0), sb.value(0));
        assert_eq!(sa.value(1), sb.value(1));
    }

    #[test]
    fn test_typos_short_strings() {
        let arr = make_arr(&["a", "ab", "", "hello"]);
        let mut rng = test_rng();
        let result = apply_typos_str(&*arr, &mut rng, 2);
        let s = result.as_string::<i32>();
        // "a" is too short (MIN_LEN_TYPO=2), should pass through
        assert_eq!(s.value(0), "a");
        // "ab" is length 2 → meets threshold
        // "" should pass through
        assert_eq!(s.value(2), "");
    }
}