indradb-lib 2.1.0

A graph database library
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
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
use super::super::bytes::*;
use crate::errors::Result;
use crate::models;
use crate::sledds::datastore::SledHolder;
use chrono::offset::Utc;
use chrono::DateTime;
use serde_json::Value as JsonValue;
use sled::Result as SledResult;
use sled::{IVec, Iter as DbIterator, Tree};
use std::io::Cursor;
use std::ops::Deref;
use std::u8;
use uuid::Uuid;

pub type OwnedPropertyItem = ((Uuid, String), JsonValue);
pub type VertexItem = (Uuid, models::Type);
pub type EdgeRangeItem = (Uuid, models::Type, DateTime<Utc>, Uuid);
pub type EdgePropertyItem = ((Uuid, models::Type, Uuid, String), JsonValue);

fn take_while_prefixed(iterator: DbIterator, prefix: Vec<u8>) -> impl Iterator<Item = SledResult<(IVec, IVec)>> {
    iterator.take_while(move |item| -> bool {
        match item {
            Ok((k, _)) => k.starts_with(&prefix),
            Err(_) => false,
        }
    })
}

pub struct VertexManager<'db: 'tree, 'tree> {
    pub holder: &'db SledHolder,
    pub tree: &'tree Tree,
}

impl<'db: 'tree, 'tree> VertexManager<'db, 'tree> {
    pub fn new(ds: &'db SledHolder) -> Self {
        VertexManager {
            holder: ds,
            tree: &ds.db.deref(),
        }
    }

    fn key(&self, id: Uuid) -> Vec<u8> {
        build(&[Component::Uuid(id)])
    }

    pub fn exists(&self, id: Uuid) -> Result<bool> {
        Ok(self.tree.get(&self.key(id))?.is_some())
    }

    pub fn get(&self, id: Uuid) -> Result<Option<models::Type>> {
        match self.tree.get(&self.key(id))? {
            Some(value_bytes) => {
                let mut cursor = Cursor::new(value_bytes.deref());
                Ok(Some(read_type(&mut cursor)))
            }
            None => Ok(None),
        }
    }

    fn iterate(&self, iterator: DbIterator) -> impl Iterator<Item = Result<VertexItem>> + '_ {
        iterator.map(move |item| -> Result<VertexItem> {
            let (k, v) = item?;

            let id = {
                debug_assert_eq!(k.len(), 16);
                let mut cursor = Cursor::new(k);
                read_uuid(&mut cursor)
            };

            let mut cursor = Cursor::new(v);
            let t = read_type(&mut cursor);
            Ok((id, t))
        })
    }

    pub fn iterate_for_range(&self, id: Uuid) -> impl Iterator<Item = Result<VertexItem>> + '_ {
        let low_key = build(&[Component::Uuid(id)]);
        let low_key_bytes: &[u8] = low_key.as_ref();
        let iter = self.tree.range(low_key_bytes..);
        self.iterate(iter)
    }

    pub fn create(&self, vertex: &models::Vertex) -> Result<()> {
        let key = self.key(vertex.id);
        self.tree.insert(&key, build(&[Component::Type(&vertex.t)]))?;
        Ok(())
    }

    pub fn delete(&self, id: Uuid) -> Result<()> {
        self.tree.remove(&self.key(id))?;

        let vertex_property_manager = VertexPropertyManager::new(&self.holder.vertex_properties);
        for item in vertex_property_manager.iterate_for_owner(id)? {
            let ((vertex_property_owner_id, vertex_property_name), _) = item?;
            vertex_property_manager.delete(vertex_property_owner_id, &vertex_property_name[..])?;
        }

        let edge_manager = EdgeManager::new(&self.holder);

        {
            let edge_range_manager = EdgeRangeManager::new(&self.holder);
            for item in edge_range_manager.iterate_for_owner(id) {
                let (edge_range_outbound_id, edge_range_t, edge_range_update_datetime, edge_range_inbound_id) = item?;
                debug_assert_eq!(edge_range_outbound_id, id);
                edge_manager.delete(
                    edge_range_outbound_id,
                    &edge_range_t,
                    edge_range_inbound_id,
                    edge_range_update_datetime,
                )?;
            }
        }

        {
            let reversed_edge_range_manager = EdgeRangeManager::new_reversed(&self.holder);
            for item in reversed_edge_range_manager.iterate_for_owner(id) {
                let (
                    reversed_edge_range_inbound_id,
                    reversed_edge_range_t,
                    reversed_edge_range_update_datetime,
                    reversed_edge_range_outbound_id,
                ) = item?;
                debug_assert_eq!(reversed_edge_range_inbound_id, id);
                edge_manager.delete(
                    reversed_edge_range_outbound_id,
                    &reversed_edge_range_t,
                    reversed_edge_range_inbound_id,
                    reversed_edge_range_update_datetime,
                )?;
            }
        }
        Ok(())
    }
}

pub struct EdgeManager<'db: 'tree, 'tree> {
    pub holder: &'db SledHolder,
    pub tree: &'tree Tree,
}

impl<'db, 'tree> EdgeManager<'db, 'tree> {
    pub fn new(ds: &'db SledHolder) -> Self {
        EdgeManager {
            holder: ds,
            tree: &ds.edges,
        }
    }

    fn key(&self, outbound_id: Uuid, t: &models::Type, inbound_id: Uuid) -> Vec<u8> {
        build(&[
            Component::Uuid(outbound_id),
            Component::Type(t),
            Component::Uuid(inbound_id),
        ])
    }

    pub fn get(&self, outbound_id: Uuid, t: &models::Type, inbound_id: Uuid) -> Result<Option<DateTime<Utc>>> {
        match self.tree.get(self.key(outbound_id, t, inbound_id))? {
            Some(value_bytes) => {
                let mut cursor = Cursor::new(value_bytes.deref());
                Ok(Some(read_datetime(&mut cursor)))
            }
            None => Ok(None),
        }
    }

    pub fn set(
        &self,
        outbound_id: Uuid,
        t: &models::Type,
        inbound_id: Uuid,
        new_update_datetime: DateTime<Utc>,
    ) -> Result<()> {
        let edge_range_manager = EdgeRangeManager::new(&self.holder);
        let reversed_edge_range_manager = EdgeRangeManager::new_reversed(&self.holder);

        if let Some(update_datetime) = self.get(outbound_id, t, inbound_id)? {
            edge_range_manager.delete(outbound_id, t, update_datetime, inbound_id)?;
            reversed_edge_range_manager.delete(inbound_id, t, update_datetime, outbound_id)?;
        }

        let key = self.key(outbound_id, t, inbound_id);
        self.tree
            .insert(key, build(&[Component::DateTime(new_update_datetime)]))?;
        edge_range_manager.set(outbound_id, t, new_update_datetime, inbound_id)?;
        reversed_edge_range_manager.set(inbound_id, t, new_update_datetime, outbound_id)?;
        Ok(())
    }

    pub fn delete(
        &self,
        outbound_id: Uuid,
        t: &models::Type,
        inbound_id: Uuid,
        update_datetime: DateTime<Utc>,
    ) -> Result<()> {
        self.tree.remove(&self.key(outbound_id, t, inbound_id))?;

        let edge_range_manager = EdgeRangeManager::new(&self.holder);
        edge_range_manager.delete(outbound_id, t, update_datetime, inbound_id)?;

        let reversed_edge_range_manager = EdgeRangeManager::new_reversed(&self.holder);
        reversed_edge_range_manager.delete(inbound_id, t, update_datetime, outbound_id)?;

        let edge_property_manager = EdgePropertyManager::new(&self.holder.edge_properties);
        for item in edge_property_manager.iterate_for_owner(outbound_id, t, inbound_id)? {
            let ((edge_property_outbound_id, edge_property_t, edge_property_inbound_id, edge_property_name), _) = item?;
            edge_property_manager.delete(
                edge_property_outbound_id,
                &edge_property_t,
                edge_property_inbound_id,
                &edge_property_name[..],
            )?;
        }
        Ok(())
    }
}

pub struct EdgeRangeManager<'tree> {
    pub tree: &'tree Tree,
}

impl<'tree> EdgeRangeManager<'tree> {
    pub fn new<'db: 'tree>(ds: &'db SledHolder) -> Self {
        EdgeRangeManager { tree: &ds.edge_ranges }
    }

    pub fn new_reversed<'db: 'tree>(ds: &'db SledHolder) -> Self {
        EdgeRangeManager {
            tree: &ds.reversed_edge_ranges,
        }
    }

    fn key(&self, first_id: Uuid, t: &models::Type, update_datetime: DateTime<Utc>, second_id: Uuid) -> Vec<u8> {
        build(&[
            Component::Uuid(first_id),
            Component::Type(t),
            Component::DateTime(update_datetime),
            Component::Uuid(second_id),
        ])
    }

    fn iterate<'it>(&self, iterator: DbIterator, prefix: Vec<u8>) -> impl Iterator<Item = Result<EdgeRangeItem>> + 'it {
        let filtered = take_while_prefixed(iterator, prefix);
        filtered.map(move |item| -> Result<EdgeRangeItem> {
            let (k, _) = item?;
            let mut cursor = Cursor::new(k);
            let first_id = read_uuid(&mut cursor);
            let t = read_type(&mut cursor);
            let update_datetime = read_datetime(&mut cursor);
            let second_id = read_uuid(&mut cursor);
            Ok((first_id, t, update_datetime, second_id))
        })
    }

    pub fn iterate_for_range<'iter, 'trans: 'iter>(
        &'trans self,
        id: Uuid,
        t: Option<&models::Type>,
        high: Option<DateTime<Utc>>,
    ) -> Result<Box<dyn Iterator<Item = Result<EdgeRangeItem>> + 'iter>> {
        match t {
            Some(t) => {
                let high = high.unwrap_or_else(|| *MAX_DATETIME);
                let prefix = build(&[Component::Uuid(id), Component::Type(t)]);
                let low_key = build(&[Component::Uuid(id), Component::Type(t), Component::DateTime(high)]);
                let low_key_bytes: &[u8] = low_key.as_ref();
                let iterator = self.tree.range(low_key_bytes..);
                Ok(Box::new(self.iterate(iterator, prefix)))
            }
            None => {
                let prefix = build(&[Component::Uuid(id)]);
                let prefix_bytes: &[u8] = prefix.as_ref();
                let iterator = self.tree.range(prefix_bytes..);
                let mapped = self.iterate(iterator, prefix);

                if let Some(high) = high {
                    // We can filter out `update_datetime`s greater than
                    // `high` via key prefix filtering, so instead we handle
                    // it here - after the key has been deserialized.
                    let filtered = mapped.filter(move |item| {
                        if let Ok((_, _, update_datetime, _)) = *item {
                            update_datetime <= high
                        } else {
                            true
                        }
                    });

                    Ok(Box::new(filtered))
                } else {
                    Ok(Box::new(mapped))
                }
            }
        }
    }

    pub fn iterate_for_owner<'iter, 'trans: 'iter>(
        &'trans self,
        id: Uuid,
    ) -> impl Iterator<Item = Result<EdgeRangeItem>> + 'iter {
        let prefix: Vec<u8> = build(&[Component::Uuid(id)]);
        let iterator = self.tree.scan_prefix(&prefix);
        self.iterate(iterator, prefix)
    }

    pub fn set(&self, first_id: Uuid, t: &models::Type, update_datetime: DateTime<Utc>, second_id: Uuid) -> Result<()> {
        let key = self.key(first_id, t, update_datetime, second_id);
        self.tree.insert(&key, &[])?;
        Ok(())
    }

    pub fn delete(
        &self,
        first_id: Uuid,
        t: &models::Type,
        update_datetime: DateTime<Utc>,
        second_id: Uuid,
    ) -> Result<()> {
        self.tree.remove(&self.key(first_id, t, update_datetime, second_id))?;
        Ok(())
    }
}

pub struct VertexPropertyManager<'tree> {
    pub tree: &'tree Tree,
}

impl<'tree> VertexPropertyManager<'tree> {
    pub fn new(tree: &'tree Tree) -> Self {
        VertexPropertyManager { tree }
    }

    fn key(&self, vertex_id: Uuid, name: &str) -> Vec<u8> {
        build(&[Component::Uuid(vertex_id), Component::UnsizedString(name)])
    }

    pub fn iterate_for_owner(&self, vertex_id: Uuid) -> Result<impl Iterator<Item = Result<OwnedPropertyItem>> + '_> {
        let prefix = build(&[Component::Uuid(vertex_id)]);
        let iterator = self.tree.scan_prefix(&prefix);

        Ok(iterator.map(move |item| -> Result<OwnedPropertyItem> {
            let (k, v) = item?;
            let mut cursor = Cursor::new(k);
            let owner_id = read_uuid(&mut cursor);
            debug_assert_eq!(vertex_id, owner_id);
            let name = read_unsized_string(&mut cursor);
            let value = serde_json::from_slice(&v)?;
            Ok(((owner_id, name), value))
        }))
    }

    pub fn get(&self, vertex_id: Uuid, name: &str) -> Result<Option<JsonValue>> {
        let key = self.key(vertex_id, name);

        match self.tree.get(&key)? {
            Some(value_bytes) => Ok(Some(serde_json::from_slice(&value_bytes)?)),
            None => Ok(None),
        }
    }

    pub fn set(&self, vertex_id: Uuid, name: &str, value: &JsonValue) -> Result<()> {
        let key = self.key(vertex_id, name);
        let value_json = serde_json::to_vec(value)?;
        self.tree.insert(key.as_slice(), value_json.as_slice())?;
        Ok(())
    }

    pub fn delete(&self, vertex_id: Uuid, name: &str) -> Result<()> {
        self.tree.remove(&self.key(vertex_id, name))?;
        Ok(())
    }
}

pub struct EdgePropertyManager<'tree> {
    pub tree: &'tree Tree,
}

impl<'tree> EdgePropertyManager<'tree> {
    pub fn new(tree: &'tree Tree) -> Self {
        EdgePropertyManager { tree }
    }

    fn key(&self, outbound_id: Uuid, t: &models::Type, inbound_id: Uuid, name: &str) -> Vec<u8> {
        build(&[
            Component::Uuid(outbound_id),
            Component::Type(t),
            Component::Uuid(inbound_id),
            Component::UnsizedString(name),
        ])
    }

    pub fn iterate_for_owner<'a>(
        &'a self,
        outbound_id: Uuid,
        t: &'a models::Type,
        inbound_id: Uuid,
    ) -> Result<Box<dyn Iterator<Item = Result<EdgePropertyItem>> + 'a>> {
        let prefix = build(&[
            Component::Uuid(outbound_id),
            Component::Type(t),
            Component::Uuid(inbound_id),
        ]);

        let iterator = self.tree.scan_prefix(&prefix);

        let mapped = iterator.map(move |item| -> Result<EdgePropertyItem> {
            let (k, v) = item?;
            let mut cursor = Cursor::new(k);

            let edge_property_outbound_id = read_uuid(&mut cursor);
            debug_assert_eq!(edge_property_outbound_id, outbound_id);

            let edge_property_t = read_type(&mut cursor);
            debug_assert_eq!(&edge_property_t, t);

            let edge_property_inbound_id = read_uuid(&mut cursor);
            debug_assert_eq!(edge_property_inbound_id, inbound_id);

            let edge_property_name = read_unsized_string(&mut cursor);

            let value = serde_json::from_slice(&v)?;
            Ok((
                (
                    edge_property_outbound_id,
                    edge_property_t,
                    edge_property_inbound_id,
                    edge_property_name,
                ),
                value,
            ))
        });

        Ok(Box::new(mapped))
    }

    pub fn get(&self, outbound_id: Uuid, t: &models::Type, inbound_id: Uuid, name: &str) -> Result<Option<JsonValue>> {
        let key = self.key(outbound_id, t, inbound_id, name);

        match self.tree.get(&key)? {
            Some(ref value_bytes) => Ok(Some(serde_json::from_slice(&value_bytes)?)),
            None => Ok(None),
        }
    }

    pub fn set(
        &self,
        outbound_id: Uuid,
        t: &models::Type,
        inbound_id: Uuid,
        name: &str,
        value: &JsonValue,
    ) -> Result<()> {
        let key = self.key(outbound_id, t, inbound_id, name);
        let value_json = serde_json::to_vec(value)?;
        self.tree.insert(key.as_slice(), value_json.as_slice())?;
        Ok(())
    }

    pub fn delete(&self, outbound_id: Uuid, t: &models::Type, inbound_id: Uuid, name: &str) -> Result<()> {
        self.tree.remove(&self.key(outbound_id, t, inbound_id, name))?;
        Ok(())
    }
}