rarena_allocator/
bytes.rs

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
use core::{ops, ptr::NonNull};

pub use dbutils::leb128::{DecodeVarintError, EncodeVarintError};
use either::Either;

use super::*;

/// A owned buffer that allocated by the ARENA
pub struct BytesMut<A: Allocator> {
  arena: Either<A, NonNull<u8>>,
  detach: bool,
  len: usize,
  allocated: Meta,
}

unsafe impl<A: Allocator + Send> Send for BytesMut<A> {}
unsafe impl<A: Allocator + Sync> Sync for BytesMut<A> {}

impl<A: Allocator> ops::Deref for BytesMut<A> {
  type Target = [u8];

  #[inline]
  fn deref(&self) -> &Self::Target {
    match self.arena {
      // SAFETY: The buffer is allocated by the ARENA, and the len and offset are valid.
      Either::Left(ref arena) => unsafe { arena.get_bytes(self.offset(), self.len) },
      Either::Right(_) => &[],
    }
  }
}

impl<A: Allocator> ops::DerefMut for BytesMut<A> {
  #[inline]
  fn deref_mut(&mut self) -> &mut Self::Target {
    let offset = self.offset();
    match self.arena {
      // SAFETY: The buffer is allocated by the ARENA, and the len and offset are valid.
      Either::Left(ref mut arena) => unsafe { arena.get_bytes_mut(offset, self.len) },
      Either::Right(_) => &mut [],
    }
  }
}

impl<A: Allocator> AsRef<[u8]> for BytesMut<A> {
  #[inline]
  fn as_ref(&self) -> &[u8] {
    self
  }
}

impl<A: Allocator> AsMut<[u8]> for BytesMut<A> {
  #[inline]
  fn as_mut(&mut self) -> &mut [u8] {
    self
  }
}

impl_write!(BytesMut<A>);

impl<A: Allocator> crate::Buffer for BytesMut<A> {
  #[inline]
  fn capacity(&self) -> usize {
    self.allocated.ptr_size as usize
  }

  #[inline]
  fn offset(&self) -> usize {
    self.allocated.ptr_offset as usize
  }

  #[inline]
  fn buffer_offset(&self) -> usize {
    self.allocated.memory_offset as usize
  }

  #[inline]
  fn buffer_capacity(&self) -> usize {
    self.allocated.memory_size as usize
  }

  #[inline]
  unsafe fn detach(&mut self) {
    self.detach = true;
  }

  #[cfg(all(feature = "memmap", not(target_family = "wasm")))]
  fn flush(&self) -> std::io::Result<()> {
    match self.arena.as_ref() {
      Either::Left(arena) => arena.flush_range(
        self.allocated.ptr_offset as usize,
        self.allocated.ptr_size as usize,
      ),
      Either::Right(_) => Ok(()),
    }
  }

  #[cfg(all(feature = "memmap", not(target_family = "wasm")))]
  fn flush_async(&self) -> std::io::Result<()> {
    match self.arena.as_ref() {
      Either::Left(arena) => arena.flush_async_range(
        self.allocated.ptr_offset as usize,
        self.allocated.ptr_size as usize,
      ),
      Either::Right(_) => Ok(()),
    }
  }
}

impl<A: Allocator> BytesMut<A> {
  impl_bytes_mut_utils!(8);
  impl_bytes_mut_utils!(u16, u32, u64, usize, u128, i16, i32, i64, isize, i128);
  impl_bytes_mut_utils!(leb(u16, u32, u64, u128, i16, i32, i64, i128));
  impl_bytes_mut_utils!(slice);
  impl_bytes_mut_utils!(align);

  impl_bytes_utils!(8);
  impl_bytes_utils!(u16, u32, u64, usize, u128, i16, i32, i64, isize, i128);
  impl_bytes_utils!(leb(u16, u32, u64, u128, i16, i32, i64, i128));
  impl_bytes_utils!(slice);

  /// Returns the mutable pointer to the buffer.
  #[inline]
  pub fn as_mut_ptr(&mut self) -> *mut u8 {
    let offset = self.offset();
    // SAFETY: The buffer is allocated by the ARENA, and the offset is valid.
    match self.arena.as_mut() {
      Either::Left(arena) => unsafe { arena.get_pointer_mut(offset) },
      Either::Right(ptr) => ptr.as_ptr(),
    }
  }

  /// Returns the pointer to the buffer.
  #[inline]
  pub fn as_ptr(&self) -> *const u8 {
    // SAFETY: The buffer is allocated by the ARENA, and the offset is valid.
    match self.arena.as_ref() {
      Either::Left(arena) => unsafe { arena.get_pointer(self.offset()) },
      Either::Right(ptr) => ptr.as_ptr(),
    }
  }

  #[inline]
  pub(super) fn null(parent_ptr: *const u8) -> Self {
    Self {
      arena: Either::Right(NonNull::dangling()),
      len: 0,
      allocated: Meta::null(parent_ptr),
      detach: false,
    }
  }

  #[inline]
  fn buffer(&self) -> &[u8] {
    match self.arena {
      // SAFETY: The buffer is allocated by the ARENA, and the len and offset are valid.
      Either::Left(ref arena) => unsafe { arena.get_bytes(self.offset(), self.capacity()) },
      Either::Right(_) => &[],
    }
  }

  #[inline]
  fn buffer_mut(&mut self) -> &mut [u8] {
    let offset = self.offset();
    let cap = self.capacity();
    match self.arena {
      // SAFETY: The buffer is allocated by the ARENA, and the len and offset are valid.
      Either::Left(ref mut arena) => unsafe { arena.get_bytes_mut(offset, cap) },
      Either::Right(_) => &mut [],
    }
  }
}

impl<A: Allocator> Drop for BytesMut<A> {
  #[inline]
  fn drop(&mut self) {
    match self.arena {
      Either::Left(_) if self.detach => {}
      // SAFETY: offset and offset + size are inbounds of the ARENA.
      Either::Left(ref mut arena) => unsafe {
        let _ = arena.dealloc(self.allocated.memory_offset, self.allocated.memory_size);
      },
      Either::Right(_) => {}
    }
  }
}

/// A buffer that allocated by the ARENA
pub struct BytesRefMut<'a, A: Allocator> {
  arena: &'a A,
  len: usize,
  pub(super) allocated: Meta,
  pub(super) detach: bool,
}

impl<A: Allocator> ops::Deref for BytesRefMut<'_, A> {
  type Target = [u8];

  #[inline]
  fn deref(&self) -> &Self::Target {
    if self.allocated.ptr_size == 0 {
      return &[];
    }

    // SAFETY: The buffer is allocated by the ARENA, and the len and offset are valid.
    unsafe { self.arena.get_bytes(self.offset(), self.len) }
  }
}

impl<A: Allocator> ops::DerefMut for BytesRefMut<'_, A> {
  #[inline]
  fn deref_mut(&mut self) -> &mut Self::Target {
    if self.allocated.ptr_size == 0 {
      return &mut [];
    }

    // SAFETY: The buffer is allocated by the ARENA, and the len and offset are valid.
    unsafe { self.arena.get_bytes_mut(self.offset(), self.len) }
  }
}

impl<A: Allocator> AsRef<[u8]> for BytesRefMut<'_, A> {
  #[inline]
  fn as_ref(&self) -> &[u8] {
    self
  }
}

impl<A: Allocator> AsMut<[u8]> for BytesRefMut<'_, A> {
  #[inline]
  fn as_mut(&mut self) -> &mut [u8] {
    self
  }
}

impl_write!(BytesRefMut<'a, A>);

impl<A: Allocator> crate::Buffer for BytesRefMut<'_, A> {
  #[inline]
  fn capacity(&self) -> usize {
    self.allocated.ptr_size as usize
  }

  #[inline]
  fn offset(&self) -> usize {
    self.allocated.ptr_offset as usize
  }

  #[inline]
  fn buffer_offset(&self) -> usize {
    self.allocated.memory_offset as usize
  }

  #[inline]
  fn buffer_capacity(&self) -> usize {
    self.allocated.memory_size as usize
  }

  #[inline]
  unsafe fn detach(&mut self) {
    self.detach = true;
  }

  #[cfg(all(feature = "memmap", not(target_family = "wasm")))]
  fn flush(&self) -> std::io::Result<()> {
    self.arena.flush_range(
      self.allocated.ptr_offset as usize,
      self.allocated.ptr_size as usize,
    )
  }

  #[cfg(all(feature = "memmap", not(target_family = "wasm")))]
  fn flush_async(&self) -> std::io::Result<()> {
    self.arena.flush_async_range(
      self.allocated.ptr_offset as usize,
      self.allocated.ptr_size as usize,
    )
  }
}

impl<'a, A: Allocator> BytesRefMut<'a, A> {
  impl_bytes_mut_utils!(8);
  impl_bytes_mut_utils!(u16, u32, u64, usize, u128, i16, i32, i64, isize, i128);
  impl_bytes_mut_utils!(leb(u16, u32, u64, u128, i16, i32, i64, i128));
  impl_bytes_mut_utils!(slice);
  impl_bytes_mut_utils!(align);

  impl_bytes_utils!(8);
  impl_bytes_utils!(u16, u32, u64, usize, u128, i16, i32, i64, isize, i128);
  impl_bytes_utils!(leb(u16, u32, u64, u128, i16, i32, i64, i128));
  impl_bytes_utils!(slice);

  /// Returns the mutable pointer to the buffer.
  #[inline]
  pub fn as_mut_ptr(&mut self) -> *mut u8 {
    // SAFETY: The buffer is allocated by the ARENA, and the offset is valid.
    unsafe { self.arena.get_pointer_mut(self.offset()) }
  }

  /// Returns the pointer to the buffer.
  #[inline]
  pub fn as_ptr(&self) -> *const u8 {
    // SAFETY: The buffer is allocated by the ARENA, and the offset is valid.
    unsafe { self.arena.get_pointer(self.offset()) }
  }

  /// Returns the length of the buffer.
  #[inline]
  pub const fn len(&self) -> usize {
    self.len
  }

  /// Returns `true` if the buffer is empty.
  #[inline]
  pub const fn is_empty(&self) -> bool {
    self.len == 0
  }

  /// Returns the remaining capacity.
  #[inline]
  pub const fn remaining(&self) -> usize {
    self.allocated.ptr_size as usize - self.len
  }

  /// SAFETY: `len` and `offset` must be valid.
  #[inline]
  pub(super) unsafe fn new(arena: &'a A, allocated: Meta) -> Self {
    Self {
      arena,
      len: 0,
      allocated,
      detach: false,
    }
  }

  #[inline]
  pub(super) fn null(arena: &'a A) -> Self {
    Self {
      allocated: Meta::null(arena.raw_ptr() as _),
      arena,
      len: 0,
      detach: false,
    }
  }

  #[allow(clippy::wrong_self_convention)]
  #[inline]
  pub(super) fn to_owned(&mut self) -> BytesMut<A> {
    if self.allocated.memory_size == 0 {
      return BytesMut::null(self.arena.raw_ptr() as _);
    }
    self.detach = true;

    BytesMut {
      arena: Either::Left(self.arena.clone()),
      len: self.len,
      allocated: self.allocated,
      detach: false,
    }
  }

  #[inline]
  fn buffer(&self) -> &[u8] {
    if self.allocated.ptr_size == 0 {
      return &[];
    }

    // SAFETY: The buffer is allocated by the ARENA, and the len and offset are valid.
    unsafe { self.arena.get_bytes(self.offset(), self.capacity()) }
  }

  #[inline]
  fn buffer_mut(&mut self) -> &mut [u8] {
    if self.allocated.ptr_size == 0 {
      return &mut [];
    }

    // SAFETY: The buffer is allocated by the ARENA, and the len and offset are valid.
    unsafe { self.arena.get_bytes_mut(self.offset(), self.capacity()) }
  }
}

impl<A: Allocator> Drop for BytesRefMut<'_, A> {
  #[inline]
  fn drop(&mut self) {
    if self.detach {
      return;
    }

    // SAFETY: offset and offset + size are inbounds of the ARENA.
    unsafe {
      self
        .arena
        .dealloc(self.allocated.memory_offset, self.allocated.memory_size);
    }
  }
}