seerdb 0.0.10

Research-grade storage engine with learned data structures
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
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393

use super::*;
use tempfile::tempdir;

#[test]
fn test_buffered_builder_basic() {
    let dir = tempdir().unwrap();
    let path = dir.path().join("test.sst");

    // Build SSTable with buffered builder
    let mut builder = SSTableBuilder::new_buffered();
    builder
        .add(Bytes::from("key1"), Bytes::from("value1"))
        .unwrap();
    builder
        .add(Bytes::from("key2"), Bytes::from("value2"))
        .unwrap();
    builder
        .add(Bytes::from("key3"), Bytes::from("value3"))
        .unwrap();

    // Finish to file
    builder.finish_to_file(&path).unwrap();

    // Read back with SSTable
    let mut sst = SSTable::open(&path).unwrap();
    assert_eq!(sst.num_entries, 3);
    assert_eq!(sst.get(b"key1").unwrap().unwrap(), Bytes::from("value1"));
    assert_eq!(sst.get(b"key2").unwrap().unwrap(), Bytes::from("value2"));
    assert_eq!(sst.get(b"key3").unwrap().unwrap(), Bytes::from("value3"));
}

#[test]
fn test_buffered_builder_to_bytes() {
    let dir = tempdir().unwrap();
    let path = dir.path().join("test.sst");

    // Build SSTable and get bytes
    let mut builder = SSTableBuilder::new_buffered();
    builder.add(Bytes::from("aaa"), Bytes::from("111")).unwrap();
    builder.add(Bytes::from("bbb"), Bytes::from("222")).unwrap();

    let bytes = builder.finish_to_bytes().unwrap();

    // Write bytes to file manually
    std::fs::write(&path, &bytes).unwrap();

    // Read back
    let mut sst = SSTable::open(&path).unwrap();
    assert_eq!(sst.num_entries, 2);
    assert_eq!(sst.get(b"aaa").unwrap().unwrap(), Bytes::from("111"));
    assert_eq!(sst.get(b"bbb").unwrap().unwrap(), Bytes::from("222"));
}

#[test]
fn test_buffered_builder_empty() {
    let builder = SSTableBuilder::new_buffered();
    assert!(builder.is_empty());
    assert_eq!(builder.num_entries(), 0);

    // Even empty builder should produce valid SSTable bytes
    let bytes = builder.finish_to_bytes().unwrap();
    assert!(bytes.len() > 0);

    // Should contain header (32 bytes) + footer (48 bytes) minimum
    assert!(bytes.len() >= 80);
}

#[test]
fn test_buffered_builder_tombstone() {
    let dir = tempdir().unwrap();
    let path = dir.path().join("test.sst");

    let mut builder = SSTableBuilder::new_buffered();
    builder
        .add(Bytes::from("key1"), Bytes::from("value1"))
        .unwrap();
    builder.add_tombstone(Bytes::from("key2")).unwrap();
    builder
        .add(Bytes::from("key3"), Bytes::from("value3"))
        .unwrap();

    builder.finish_to_file(&path).unwrap();

    let mut sst = SSTable::open(&path).unwrap();
    assert_eq!(sst.num_entries, 3);
    assert_eq!(sst.get(b"key1").unwrap().unwrap(), Bytes::from("value1"));
    // key2 is a tombstone - should return None
    assert!(sst.get(b"key2").unwrap().is_none());
    assert_eq!(sst.get(b"key3").unwrap().unwrap(), Bytes::from("value3"));
}

#[test]
fn test_buffered_builder_max_sequence() {
    let dir = tempdir().unwrap();
    let path = dir.path().join("test.sst");

    let mut builder = SSTableBuilder::new_buffered().with_max_sequence(12345);
    builder
        .add(Bytes::from("key1"), Bytes::from("value1"))
        .unwrap();

    builder.finish_to_file(&path).unwrap();

    let sst = SSTable::open(&path).unwrap();
    assert_eq!(sst.max_sequence(), 12345);
}

#[test]
fn test_buffered_builder_many_entries() {
    let dir = tempdir().unwrap();
    let path = dir.path().join("test.sst");

    let mut builder = SSTableBuilder::new_buffered();

    // Add 1000 entries to force multiple data blocks
    for i in 0..1000 {
        let key = format!("key{:06}", i);
        let value = format!("value{:06}", i);
        builder.add(Bytes::from(key), Bytes::from(value)).unwrap();
    }

    assert_eq!(builder.num_entries(), 1000);

    builder.finish_to_file(&path).unwrap();

    let mut sst = SSTable::open(&path).unwrap();
    assert_eq!(sst.num_entries, 1000);

    // Spot check
    assert_eq!(
        sst.get(b"key000000").unwrap().unwrap(),
        Bytes::from("value000000")
    );
    assert_eq!(
        sst.get(b"key000500").unwrap().unwrap(),
        Bytes::from("value000500")
    );
    assert_eq!(
        sst.get(b"key000999").unwrap().unwrap(),
        Bytes::from("value000999")
    );
}

#[test]
fn test_buffered_builder_checksum_valid() {
    let dir = tempdir().unwrap();
    let path = dir.path().join("test.sst");

    let mut builder = SSTableBuilder::new_buffered();
    builder
        .add(Bytes::from("key1"), Bytes::from("value1"))
        .unwrap();

    let bytes = builder.finish_to_bytes().unwrap();
    std::fs::write(&path, &bytes).unwrap();

    // Opening should validate checksum
    let sst = SSTable::open(&path).unwrap();
    assert_eq!(sst.num_entries, 1);
}

#[test]
fn test_buffered_vs_file_builder_equivalence() {
    let dir = tempdir().unwrap();
    let path_buffered = dir.path().join("buffered.sst");
    let path_file = dir.path().join("file.sst");

    // Build with buffered builder
    let mut buffered = SSTableBuilder::new_buffered().with_max_sequence(100);
    buffered
        .add(Bytes::from("key1"), Bytes::from("value1"))
        .unwrap();
    buffered
        .add(Bytes::from("key2"), Bytes::from("value2"))
        .unwrap();
    buffered.finish_to_file(&path_buffered).unwrap();

    // Build with file-based builder
    let mut file_builder = SSTableBuilder::create(&path_file)
        .unwrap()
        .with_max_sequence(100);
    file_builder
        .add(Bytes::from("key1"), Bytes::from("value1"))
        .unwrap();
    file_builder
        .add(Bytes::from("key2"), Bytes::from("value2"))
        .unwrap();
    file_builder.finish().unwrap();

    // Both should be readable and contain same data
    let mut sst_buffered = SSTable::open(&path_buffered).unwrap();
    let mut sst_file = SSTable::open(&path_file).unwrap();

    assert_eq!(sst_buffered.num_entries, sst_file.num_entries);
    assert_eq!(sst_buffered.max_sequence(), sst_file.max_sequence());
    assert_eq!(
        sst_buffered.get(b"key1").unwrap(),
        sst_file.get(b"key1").unwrap()
    );
    assert_eq!(
        sst_buffered.get(b"key2").unwrap(),
        sst_file.get(b"key2").unwrap()
    );
}

#[test]
fn test_sstable_iter_rev() {
    let dir = tempdir().unwrap();
    let path = dir.path().join("rev.sst");

    let mut builder = SSTableBuilder::new_buffered();
    builder
        .add(Bytes::from("key1"), Bytes::from("val1"))
        .unwrap();
    builder
        .add(Bytes::from("key2"), Bytes::from("val2"))
        .unwrap();
    builder
        .add(Bytes::from("key3"), Bytes::from("val3"))
        .unwrap();

    builder.finish_to_file(&path).unwrap();

    let mut sst = SSTable::open(&path).unwrap();
    let entries: Vec<_> = sst.iter_rev().unwrap().map(|r| r.unwrap()).collect();

    assert_eq!(entries.len(), 3);
    assert_eq!(entries[0].0, Bytes::from("key3"));
    assert_eq!(entries[1].0, Bytes::from("key2"));
    assert_eq!(entries[2].0, Bytes::from("key1"));
}

#[test]
fn test_buffered_builder_large_value() {
    let dir = tempdir().unwrap();
    let path = dir.path().join("test.sst");

    let mut builder = SSTableBuilder::new_buffered();
    let large_value = vec![0xABu8; 100_000]; // 100KB value

    builder
        .add(Bytes::from("large"), Bytes::from(large_value.clone()))
        .unwrap();

    builder.finish_to_file(&path).unwrap();

    let mut sst = SSTable::open(&path).unwrap();
    assert_eq!(sst.get(b"large").unwrap().unwrap().as_ref(), &large_value);
}

// ========================================================================
// MVCC Tests
// ========================================================================

#[test]
fn test_mvcc_add_internal_basic() {
    use crate::types::{InternalKey, ValueType};

    let dir = tempdir().unwrap();
    let path = dir.path().join("mvcc.sst");

    let mut builder = SSTableBuilder::new_buffered();

    // Add entries with different sequence numbers for same key
    // Higher seq = newer version, but sorted FIRST due to encoding
    let ikey1 = InternalKey::new(Bytes::from("key1"), 100, ValueType::Value);
    let ikey2 = InternalKey::new(Bytes::from("key1"), 200, ValueType::Value);
    let ikey3 = InternalKey::new(Bytes::from("key2"), 100, ValueType::Value);

    // Add in sorted order (required for SSTable builder)
    // key1@200 < key1@100 < key2@100 (user_key ASC, seq DESC)
    builder.add_internal(&ikey2, Bytes::from("v1_200")).unwrap();
    builder.add_internal(&ikey1, Bytes::from("v1_100")).unwrap();
    builder.add_internal(&ikey3, Bytes::from("v2_100")).unwrap();

    builder.finish_to_file(&path).unwrap();

    let mut sst = SSTable::open(&path).unwrap();
    assert_eq!(sst.num_entries, 3);
    assert_eq!(sst.max_sequence(), 200);

    // MVCC lookup: snapshot_seq=200 should see v1_200
    let result = sst.get_mvcc(b"key1", 200).unwrap();
    assert_eq!(result, Some(Bytes::from("v1_200")));

    // MVCC lookup: snapshot_seq=150 should see v1_100 (newest <= 150)
    let result = sst.get_mvcc(b"key1", 150).unwrap();
    assert_eq!(result, Some(Bytes::from("v1_100")));

    // MVCC lookup: snapshot_seq=50 should see nothing (no version <= 50)
    let result = sst.get_mvcc(b"key1", 50).unwrap();
    assert_eq!(result, None);

    // key2 lookup
    let result = sst.get_mvcc(b"key2", 200).unwrap();
    assert_eq!(result, Some(Bytes::from("v2_100")));
}

#[test]
fn test_mvcc_tombstone() {
    use crate::types::{InternalKey, ValueType};

    let dir = tempdir().unwrap();
    let path = dir.path().join("mvcc_tomb.sst");

    let mut builder = SSTableBuilder::new_buffered();

    // key1: value at seq 100, tombstone at seq 200
    let ikey1_tomb = InternalKey::new(Bytes::from("key1"), 200, ValueType::Deletion);
    let ikey1_val = InternalKey::new(Bytes::from("key1"), 100, ValueType::Value);

    builder.add_internal(&ikey1_tomb, Bytes::new()).unwrap();
    builder
        .add_internal(&ikey1_val, Bytes::from("value"))
        .unwrap();

    builder.finish_to_file(&path).unwrap();

    let mut sst = SSTable::open(&path).unwrap();

    // snapshot_seq=200 should see tombstone (deleted)
    let result = sst.get_mvcc(b"key1", 200).unwrap();
    assert_eq!(result, None);

    // snapshot_seq=150 should see the value (tombstone not visible)
    let result = sst.get_mvcc(b"key1", 150).unwrap();
    assert_eq!(result, Some(Bytes::from("value")));
}

#[test]
fn test_mvcc_many_versions() {
    use crate::types::{InternalKey, ValueType};

    let dir = tempdir().unwrap();
    let path = dir.path().join("mvcc_many.sst");

    let mut builder = SSTableBuilder::new_buffered();

    // Add 100 versions of the same key
    for seq in (1..=100).rev() {
        let ikey = InternalKey::new(Bytes::from("key"), seq * 10, ValueType::Value);
        let value = format!("value_seq{}", seq * 10);
        builder.add_internal(&ikey, Bytes::from(value)).unwrap();
    }

    builder.finish_to_file(&path).unwrap();

    let mut sst = SSTable::open(&path).unwrap();
    assert_eq!(sst.num_entries, 100);

    // Latest version
    let result = sst.get_mvcc(b"key", 1000).unwrap();
    assert_eq!(result, Some(Bytes::from("value_seq1000")));

    // Middle version
    let result = sst.get_mvcc(b"key", 505).unwrap();
    assert_eq!(result, Some(Bytes::from("value_seq500")));

    // Oldest version
    let result = sst.get_mvcc(b"key", 10).unwrap();
    assert_eq!(result, Some(Bytes::from("value_seq10")));

    // Too old
    let result = sst.get_mvcc(b"key", 5).unwrap();
    assert_eq!(result, None);
}

#[test]
fn test_mvcc_bloom_filter_uses_user_key() {
    use crate::types::{InternalKey, ValueType};

    let dir = tempdir().unwrap();
    let path = dir.path().join("mvcc_bloom.sst");

    let mut builder = SSTableBuilder::new_buffered();

    let ikey = InternalKey::new(Bytes::from("testkey"), 100, ValueType::Value);
    builder
        .add_internal(&ikey, Bytes::from("testvalue"))
        .unwrap();

    builder.finish_to_file(&path).unwrap();

    let sst = SSTable::open(&path).unwrap();

    // Bloom filter should be indexed by user_key, not encoded InternalKey
    assert!(sst.may_contain(b"testkey"));

    // A key that doesn't exist should (probably) return false
    // (Bloom filters can have false positives but should not for completely different keys)
    // This tests that the bloom filter was built with user_key
    assert!(!sst.may_contain(b"nonexistent_key_that_is_very_different"));
}