lio 0.4.1

A platform-independent async I/O library with native support for io_uring (Linux), IOCP (Windows), and kqueue (macOS)
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

mod common;

use common::poll_until_recv;
use lio::{
  Lio,
  api::{resource::Resource, truncate},
};
use std::{ffi::CString, os::fd::FromRawFd, sync::mpsc};

#[test]
fn test_truncate_shrink_file() {
  let mut lio = Lio::new(256).unwrap();

  let path = CString::new("/tmp/lio_test_truncate_shrink.txt").unwrap();

  // Create file with data
  let fd = unsafe {
    let fd = libc::open(
      path.as_ptr(),
      libc::O_CREAT | libc::O_RDWR | libc::O_TRUNC,
      0o644,
    );
    libc::write(fd, b"0123456789ABCDEF".as_ptr() as *const libc::c_void, 16);
    fd
  };

  // Keep resource alive until after fstat (Resource closes fd on last drop)
  let resource = unsafe { Resource::from_raw_fd(fd) };

  let (sender, receiver) = mpsc::channel();
  let sender1 = sender.clone();

  // Truncate to 5 bytes
  truncate(&resource, 5).with_lio(&mut lio).send_with(sender1);

  poll_until_recv(&mut lio, &receiver).expect("Failed to truncate file");

  // Verify size
  unsafe {
    let mut stat: libc::stat = std::mem::zeroed();
    libc::fstat(fd, &mut stat);
    assert_eq!(stat.st_size, 5);

    // Verify content
    let mut buf = vec![0u8; 10];
    libc::lseek(fd, 0, libc::SEEK_SET);
    let read_bytes = libc::read(fd, buf.as_mut_ptr() as *mut libc::c_void, 10);
    assert_eq!(read_bytes, 5);
    assert_eq!(&buf[..5], b"01234");

    libc::unlink(path.as_ptr());
  }
  // resource dropped here, closing fd
  drop(resource);
}

#[test]
fn test_truncate_extend_file() {
  let mut lio = Lio::new(256).unwrap();

  let path = CString::new("/tmp/lio_test_truncate_extend.txt").unwrap();

  // Create file with data
  let fd = unsafe {
    let fd = libc::open(
      path.as_ptr(),
      libc::O_CREAT | libc::O_RDWR | libc::O_TRUNC,
      0o644,
    );
    libc::write(fd, b"Hello".as_ptr() as *const libc::c_void, 5);
    fd
  };

  let resource = unsafe { Resource::from_raw_fd(fd) };

  let (sender, receiver) = mpsc::channel();
  let sender1 = sender.clone();

  // Extend to 20 bytes
  truncate(&resource, 20).with_lio(&mut lio).send_with(sender1);

  poll_until_recv(&mut lio, &receiver).expect("Failed to truncate file");

  // Verify size
  unsafe {
    let mut stat: libc::stat = std::mem::zeroed();
    libc::fstat(fd, &mut stat);
    assert_eq!(stat.st_size, 20);

    // Verify content (extended part should be zeros)
    let mut buf = vec![0u8; 20];
    libc::lseek(fd, 0, libc::SEEK_SET);
    let read_bytes = libc::read(fd, buf.as_mut_ptr() as *mut libc::c_void, 20);
    assert_eq!(read_bytes, 20);
    assert_eq!(&buf[..5], b"Hello");
    assert_eq!(&buf[5..20], &[0u8; 15]);

    libc::unlink(path.as_ptr());
  }
  drop(resource);
}

#[test]
fn test_truncate_to_zero() {
  let mut lio = Lio::new(256).unwrap();

  let path = CString::new("/tmp/lio_test_truncate_zero.txt").unwrap();

  // Create file with data
  let fd = unsafe {
    let fd = libc::open(
      path.as_ptr(),
      libc::O_CREAT | libc::O_RDWR | libc::O_TRUNC,
      0o644,
    );
    libc::write(fd, b"Some data here".as_ptr() as *const libc::c_void, 14);
    fd
  };

  let resource = unsafe { Resource::from_raw_fd(fd) };

  let (sender, receiver) = mpsc::channel();
  let sender1 = sender.clone();

  // Truncate to 0 bytes
  truncate(&resource, 0).with_lio(&mut lio).send_with(sender1);

  poll_until_recv(&mut lio, &receiver)
    .expect("Failed to truncate file to zero");

  // Verify size
  unsafe {
    let mut stat: libc::stat = std::mem::zeroed();
    libc::fstat(fd, &mut stat);
    assert_eq!(stat.st_size, 0);

    // Try to read (should get 0 bytes)
    let mut buf = vec![0u8; 10];
    libc::lseek(fd, 0, libc::SEEK_SET);
    let read_bytes = libc::read(fd, buf.as_mut_ptr() as *mut libc::c_void, 10);
    assert_eq!(read_bytes, 0);

    libc::unlink(path.as_ptr());
  }
  drop(resource);
}

#[test]
fn test_truncate_same_size() {
  let mut lio = Lio::new(256).unwrap();

  let path = CString::new("/tmp/lio_test_truncate_same.txt").unwrap();

  let test_data = b"ExactSize";

  // Create file with data
  let fd = unsafe {
    let fd = libc::open(
      path.as_ptr(),
      libc::O_CREAT | libc::O_RDWR | libc::O_TRUNC,
      0o644,
    );
    libc::write(fd, test_data.as_ptr() as *const libc::c_void, test_data.len());
    fd
  };

  let resource = unsafe { Resource::from_raw_fd(fd) };

  let (sender, receiver) = mpsc::channel();
  let sender1 = sender.clone();

  // Truncate to same size
  truncate(&resource, test_data.len() as u64)
    .with_lio(&mut lio)
    .send_with(sender1);

  poll_until_recv(&mut lio, &receiver).expect("Failed to truncate file");

  // Verify size and content unchanged
  unsafe {
    let mut stat: libc::stat = std::mem::zeroed();
    libc::fstat(fd, &mut stat);
    assert_eq!(stat.st_size as usize, test_data.len());

    let mut buf = vec![0u8; test_data.len()];
    libc::lseek(fd, 0, libc::SEEK_SET);
    let read_bytes =
      libc::read(fd, buf.as_mut_ptr() as *mut libc::c_void, test_data.len());
    assert_eq!(read_bytes as usize, test_data.len());
    assert_eq!(&buf, test_data);

    libc::unlink(path.as_ptr());
  }
  drop(resource);
}

#[test]
fn test_truncate_then_write() {
  let mut lio = Lio::new(256).unwrap();

  let path = CString::new("/tmp/lio_test_truncate_write.txt").unwrap();

  // Create file with data
  let fd = unsafe {
    let fd = libc::open(
      path.as_ptr(),
      libc::O_CREAT | libc::O_RDWR | libc::O_TRUNC,
      0o644,
    );
    libc::write(fd, b"Old data here".as_ptr() as *const libc::c_void, 13);
    fd
  };

  let resource = unsafe { Resource::from_raw_fd(fd) };

  let (sender, receiver) = mpsc::channel();
  let sender1 = sender.clone();

  // Truncate to 5 bytes
  truncate(&resource, 5).with_lio(&mut lio).send_with(sender1);

  poll_until_recv(&mut lio, &receiver).expect("Failed to truncate file");

  // Write new data
  unsafe {
    libc::lseek(fd, 5, libc::SEEK_SET);
    libc::write(fd, b"New".as_ptr() as *const libc::c_void, 3);
  }

  // Verify
  unsafe {
    let mut buf = vec![0u8; 10];
    libc::lseek(fd, 0, libc::SEEK_SET);
    let read_bytes = libc::read(fd, buf.as_mut_ptr() as *mut libc::c_void, 10);
    assert_eq!(read_bytes, 8);
    assert_eq!(&buf[..8], b"Old dNew");

    libc::unlink(path.as_ptr());
  }
  drop(resource);
}

#[test]
fn test_truncate_large_file() {
  let mut lio = lio::Lio::new(256).unwrap();

  let path = CString::new("/tmp/lio_test_truncate_large.txt").unwrap();

  // Create file with large data (1MB)
  let large_data: Vec<u8> = (0..1024 * 1024).map(|i| (i % 256) as u8).collect();
  let fd = unsafe {
    let fd = libc::open(
      path.as_ptr(),
      libc::O_CREAT | libc::O_RDWR | libc::O_TRUNC,
      0o644,
    );
    libc::write(
      fd,
      large_data.as_ptr() as *const libc::c_void,
      large_data.len(),
    );
    fd
  };

  let resource = unsafe { Resource::from_raw_fd(fd) };

  let (sender, receiver) = mpsc::channel();
  let sender1 = sender.clone();

  // Truncate to 1KB
  truncate(&resource, 1024).with_lio(&mut lio).send_with(sender1);

  poll_until_recv(&mut lio, &receiver).expect("Failed to truncate large file");

  // Verify size
  unsafe {
    let mut stat: libc::stat = std::mem::zeroed();
    libc::fstat(fd, &mut stat);
    assert_eq!(stat.st_size, 1024);

    // Verify content
    let mut buf = vec![0u8; 1024];
    libc::lseek(fd, 0, libc::SEEK_SET);
    let read_bytes =
      libc::read(fd, buf.as_mut_ptr() as *mut libc::c_void, 1024);
    assert_eq!(read_bytes, 1024);
    assert_eq!(&buf, &large_data[..1024]);

    libc::unlink(path.as_ptr());
  }
  drop(resource);
}

#[test]
fn test_truncate_multiple_times() {
  let mut lio = lio::Lio::new(256).unwrap();

  let path = CString::new("/tmp/lio_test_truncate_multiple.txt").unwrap();

  // Create file
  let fd = unsafe {
    let fd = libc::open(
      path.as_ptr(),
      libc::O_CREAT | libc::O_RDWR | libc::O_TRUNC,
      0o644,
    );
    libc::write(fd, b"0123456789".as_ptr() as *const libc::c_void, 10);
    fd
  };

  let resource = unsafe { Resource::from_raw_fd(fd) };

  let (sender, receiver) = mpsc::channel();

  // Truncate multiple times
  let sender1 = sender.clone();
  truncate(&resource, 8).with_lio(&mut lio).send_with(sender1);
  poll_until_recv(&mut lio, &receiver).expect("First truncate failed");

  let sender2 = sender.clone();
  truncate(&resource, 5).with_lio(&mut lio).send_with(sender2);
  poll_until_recv(&mut lio, &receiver).expect("Second truncate failed");

  let sender3 = sender.clone();
  truncate(&resource, 10).with_lio(&mut lio).send_with(sender3);
  poll_until_recv(&mut lio, &receiver).expect("Third truncate failed");

  let sender4 = sender.clone();
  truncate(&resource, 3).with_lio(&mut lio).send_with(sender4);
  poll_until_recv(&mut lio, &receiver).expect("Fourth truncate failed");

  // Verify final size
  unsafe {
    let mut stat: libc::stat = std::mem::zeroed();
    libc::fstat(fd, &mut stat);
    assert_eq!(stat.st_size, 3);

    let mut buf = vec![0u8; 10];
    libc::lseek(fd, 0, libc::SEEK_SET);
    let read_bytes = libc::read(fd, buf.as_mut_ptr() as *mut libc::c_void, 10);
    assert_eq!(read_bytes, 3);
    assert_eq!(&buf[..3], b"012");

    libc::unlink(path.as_ptr());
  }
  drop(resource);
}

#[test]
fn test_truncate_concurrent() {
  let mut lio = lio::Lio::new(256).unwrap();

  // Test truncating multiple files concurrently
  for i in 0..10 {
    let path =
      CString::new(format!("/tmp/lio_test_truncate_concurrent_{}.txt", i))
        .unwrap();

    let fd = unsafe {
      let fd = libc::open(
        path.as_ptr(),
        libc::O_CREAT | libc::O_RDWR | libc::O_TRUNC,
        0o644,
      );
      libc::write(fd, b"0123456789ABCDEF".as_ptr() as *const libc::c_void, 16);
      fd
    };

    let resource = unsafe { Resource::from_raw_fd(fd) };

    let (sender, receiver) = mpsc::channel();

    truncate(&resource, 5).with_lio(&mut lio).send_with(sender.clone());

    poll_until_recv(&mut lio, &receiver).expect("Failed to truncate");

    unsafe {
      let mut stat: libc::stat = std::mem::zeroed();
      libc::fstat(fd, &mut stat);
      assert_eq!(stat.st_size, 5);

      libc::unlink(path.as_ptr());
    }
    drop(resource);
  }
}