logo
  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
//! Archived index map implementation.
//!
//! During archiving, hashmaps are built into minimal perfect hashmaps using
//! [compress, hash and displace](http://cmph.sourceforge.net/papers/esa09.pdf).

#[cfg(feature = "validation")]
pub mod validation;

use crate::{
    collections::{
        hash_index::{ArchivedHashIndex, HashBuilder, HashIndexResolver},
        util::Entry,
    },
    out_field, Archived, RelPtr,
};
use core::{borrow::Borrow, fmt, hash::Hash, iter::FusedIterator, marker::PhantomData};

/// An archived `IndexMap`.
#[cfg_attr(feature = "strict", repr(C))]
pub struct ArchivedIndexMap<K, V> {
    index: ArchivedHashIndex,
    pivots: RelPtr<Archived<usize>>,
    entries: RelPtr<Entry<K, V>>,
}

impl<K, V> ArchivedIndexMap<K, V> {
    #[inline]
    unsafe fn pivot(&self, index: usize) -> usize {
        from_archived!(*self.pivots.as_ptr().add(index)) as usize
    }

    #[inline]
    unsafe fn entry(&self, index: usize) -> &Entry<K, V> {
        &*self.entries.as_ptr().add(index)
    }

    #[inline]
    fn find<Q: ?Sized>(&self, k: &Q) -> Option<usize>
    where
        K: Borrow<Q>,
        Q: Hash + Eq,
    {
        self.index.index(k).and_then(|pivot_index| {
            let index = unsafe { self.pivot(pivot_index) };
            let entry = unsafe { self.entry(index) };
            if entry.key.borrow() == k {
                Some(index)
            } else {
                None
            }
        })
    }

    /// Returns whether a key is present in the hash map.
    #[inline]
    pub fn contains_key<Q: ?Sized>(&self, k: &Q) -> bool
    where
        K: Borrow<Q>,
        Q: Hash + Eq,
    {
        self.find(k).is_some()
    }

    /// Returns the first key-value pair.
    #[inline]
    pub fn first(&self) -> Option<(&K, &V)> {
        if !self.is_empty() {
            let entry = unsafe { self.entry(0) };
            Some((&entry.key, &entry.value))
        } else {
            None
        }
    }

    /// Gets the value associated with the given key.
    #[inline]
    pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&V>
    where
        K: Borrow<Q>,
        Q: Hash + Eq,
    {
        self.find(k)
            .map(|index| unsafe { &self.entry(index).value })
    }

    /// Gets the index, key, and value associated with the given key.
    #[inline]
    pub fn get_full<Q: ?Sized>(&self, k: &Q) -> Option<(usize, &K, &V)>
    where
        K: Borrow<Q>,
        Q: Hash + Eq,
    {
        self.find(k).map(|index| {
            let entry = unsafe { &self.entry(index) };
            (index, &entry.key, &entry.value)
        })
    }

    /// Gets a key-value pair by index.
    #[inline]
    pub fn get_index(&self, index: usize) -> Option<(&K, &V)> {
        if index < self.len() {
            let entry = unsafe { &self.entry(index) };
            Some((&entry.key, &entry.value))
        } else {
            None
        }
    }

    /// Gets the index of a key if it exists in the map.
    #[inline]
    pub fn get_index_of<Q: ?Sized>(&self, key: &Q) -> Option<usize>
    where
        K: Borrow<Q>,
        Q: Hash + Eq,
    {
        self.find(key)
    }

    /// Gets the key-value pair associated with the given key.
    #[inline]
    pub fn get_key_value<Q: ?Sized>(&self, k: &Q) -> Option<(&K, &V)>
    where
        K: Borrow<Q>,
        Q: Hash + Eq,
    {
        self.find(k).map(|index| {
            let entry = unsafe { &self.entry(index) };
            (&entry.key, &entry.value)
        })
    }

    /// Gets the hasher for this index map.
    #[inline]
    pub fn hasher(&self) -> HashBuilder {
        self.index.hasher()
    }

    /// Returns `true` if the map contains no elements.
    #[inline]
    pub const fn is_empty(&self) -> bool {
        self.len() == 0
    }

    #[inline]
    fn raw_iter(&self) -> RawIter<K, V> {
        RawIter::new(self.entries.as_ptr().cast(), self.len())
    }

    /// Returns an iterator over the key-value pairs of the map in order
    #[inline]
    pub fn iter(&self) -> Iter<K, V> {
        Iter {
            inner: self.raw_iter(),
        }
    }

    /// Returns an iterator over the keys of the map in order
    #[inline]
    pub fn keys(&self) -> Keys<K, V> {
        Keys {
            inner: self.raw_iter(),
        }
    }

    /// Returns the last key-value pair.
    #[inline]
    pub fn last(&self) -> Option<(&K, &V)> {
        if !self.is_empty() {
            let entry = unsafe { self.entry(self.len() - 1) };
            Some((&entry.key, &entry.value))
        } else {
            None
        }
    }

    /// Gets the number of items in the index map.
    #[inline]
    pub const fn len(&self) -> usize {
        self.index.len()
    }

    /// Returns an iterator over the values of the map in order.
    #[inline]
    pub fn values(&self) -> Values<K, V> {
        Values {
            inner: self.raw_iter(),
        }
    }

    /// Resolves an archived index map from a given length and parameters.
    ///
    /// # Safety
    ///
    /// - `len` must be the number of elements that were serialized
    /// - `pos` must be the position of `out` within the archive
    /// - `resolver` must be the result of serializing a hash map
    pub unsafe fn resolve_from_len(
        len: usize,
        pos: usize,
        resolver: IndexMapResolver,
        out: *mut Self,
    ) {
        let (fp, fo) = out_field!(out.index);
        ArchivedHashIndex::resolve_from_len(len, pos + fp, resolver.index_resolver, fo);

        let (fp, fo) = out_field!(out.pivots);
        RelPtr::emplace(pos + fp, resolver.pivots_pos, fo);

        let (fp, fo) = out_field!(out.entries);
        RelPtr::emplace(pos + fp, resolver.entries_pos, fo);
    }
}

#[cfg(feature = "alloc")]
const _: () = {
    use crate::{
        ser::{ScratchSpace, Serializer},
        Serialize,
    };

    impl<K, V> ArchivedIndexMap<K, V> {
        /// Serializes an iterator of key-value pairs as an index map.
        ///
        /// # Safety
        ///
        /// - The keys returned by the iterator must be unique
        /// - The index function must return the index of the given key within the iterator
        pub unsafe fn serialize_from_iter_index<'a, UK, UV, I, F, S>(
            iter: I,
            index: F,
            serializer: &mut S,
        ) -> Result<IndexMapResolver, S::Error>
        where
            UK: 'a + Serialize<S, Archived = K> + Hash + Eq,
            UV: 'a + Serialize<S, Archived = V>,
            I: Clone + ExactSizeIterator<Item = (&'a UK, &'a UV)>,
            F: Fn(&UK) -> usize,
            S: Serializer + ScratchSpace + ?Sized,
        {
            use crate::ScratchVec;

            let len = iter.len();

            let mut entries = ScratchVec::new(serializer, iter.len())?;
            entries.set_len(len);
            let index_resolver =
                ArchivedHashIndex::build_and_serialize(iter.clone(), serializer, &mut entries)?;
            let mut entries = entries.assume_init();

            // Serialize entries
            let mut resolvers = ScratchVec::new(serializer, iter.len())?;
            for (key, value) in iter.clone() {
                resolvers.push((key.serialize(serializer)?, value.serialize(serializer)?));
            }

            let entries_pos = serializer.align_for::<Entry<K, V>>()?;
            for ((key, value), (key_resolver, value_resolver)) in iter.zip(resolvers.drain(..)) {
                serializer
                    .resolve_aligned(&Entry { key, value }, (key_resolver, value_resolver))?;
            }

            // Serialize pivots
            let pivots_pos = serializer.align_for::<Archived<usize>>()?;
            for (key, _) in entries.drain(..) {
                serializer.resolve_aligned(&index(key), ())?;
            }

            // Free scratch vecs
            resolvers.free(serializer)?;
            entries.free(serializer)?;

            Ok(IndexMapResolver {
                index_resolver,
                pivots_pos,
                entries_pos,
            })
        }
    }
};

impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for ArchivedIndexMap<K, V> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_map().entries(self.iter()).finish()
    }
}

impl<K: PartialEq, V: PartialEq> PartialEq for ArchivedIndexMap<K, V> {
    fn eq(&self, other: &Self) -> bool {
        self.iter().eq(other.iter())
    }
}

struct RawIter<'a, K, V> {
    current: *const Entry<K, V>,
    remaining: usize,
    _phantom: PhantomData<(&'a K, &'a V)>,
}

impl<'a, K, V> RawIter<'a, K, V> {
    #[inline]
    fn new(pairs: *const Entry<K, V>, len: usize) -> Self {
        Self {
            current: pairs,
            remaining: len,
            _phantom: PhantomData,
        }
    }
}

impl<'a, K, V> Iterator for RawIter<'a, K, V> {
    type Item = (&'a K, &'a V);

    #[inline]
    fn next(&mut self) -> Option<Self::Item> {
        unsafe {
            if self.remaining == 0 {
                None
            } else {
                let result = self.current;
                self.current = self.current.add(1);
                self.remaining -= 1;
                let entry = &*result;
                Some((&entry.key, &entry.value))
            }
        }
    }

    #[inline]
    fn size_hint(&self) -> (usize, Option<usize>) {
        (self.remaining, Some(self.remaining))
    }
}

impl<'a, K, V> ExactSizeIterator for RawIter<'a, K, V> {}
impl<'a, K, V> FusedIterator for RawIter<'a, K, V> {}

/// An iterator over the key-value pairs of an index map.
#[repr(transparent)]
pub struct Iter<'a, K, V> {
    inner: RawIter<'a, K, V>,
}

impl<'a, K, V> Iterator for Iter<'a, K, V> {
    type Item = (&'a K, &'a V);

    #[inline]
    fn next(&mut self) -> Option<Self::Item> {
        self.inner.next()
    }

    #[inline]
    fn size_hint(&self) -> (usize, Option<usize>) {
        self.inner.size_hint()
    }
}

impl<K, V> ExactSizeIterator for Iter<'_, K, V> {}
impl<K, V> FusedIterator for Iter<'_, K, V> {}

/// An iterator over the keys of an index map.
#[repr(transparent)]
pub struct Keys<'a, K, V> {
    inner: RawIter<'a, K, V>,
}

impl<'a, K, V> Iterator for Keys<'a, K, V> {
    type Item = &'a K;

    #[inline]
    fn next(&mut self) -> Option<Self::Item> {
        self.inner.next().map(|(k, _)| k)
    }

    #[inline]
    fn size_hint(&self) -> (usize, Option<usize>) {
        self.inner.size_hint()
    }
}

impl<K, V> ExactSizeIterator for Keys<'_, K, V> {}
impl<K, V> FusedIterator for Keys<'_, K, V> {}

/// An iterator over the values of an index map.
#[repr(transparent)]
pub struct Values<'a, K, V> {
    inner: RawIter<'a, K, V>,
}

impl<'a, K, V> Iterator for Values<'a, K, V> {
    type Item = &'a V;

    #[inline]
    fn next(&mut self) -> Option<Self::Item> {
        self.inner.next().map(|(_, v)| v)
    }

    #[inline]
    fn size_hint(&self) -> (usize, Option<usize>) {
        self.inner.size_hint()
    }
}

impl<K, V> ExactSizeIterator for Values<'_, K, V> {}
impl<K, V> FusedIterator for Values<'_, K, V> {}

// Archive implementations

/// The resolver for an `IndexMap`.
pub struct IndexMapResolver {
    index_resolver: HashIndexResolver,
    pivots_pos: usize,
    entries_pos: usize,
}