manifile 0.0.0

Generic purpose append only manifest file implementation.
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

use super::*;

#[cfg(not(feature = "std"))]
use std::vec::Vec;

use crate::MANIFEST_DELETIONS_REWRITE_THRESHOLD;

impl BackedFile for Vec<u8> {
  type Options = Option<usize>;

  type Error = core::convert::Infallible;

  #[cfg(feature = "std")]
  fn open<P: AsRef<std::path::Path>>(
    _path: P,
    opts: Self::Options,
  ) -> Result<(bool, Self), Self::Error>
  where
    Self: Sized,
  {
    Ok((
      true,
      Vec::with_capacity(opts.unwrap_or(MANIFEST_DELETIONS_REWRITE_THRESHOLD as usize)),
    ))
  }

  #[cfg(not(feature = "std"))]
  fn open(opts: Self::Options) -> Result<(bool, Self), Self::Error>
  where
    Self: Sized,
  {
    Ok((
      true,
      Vec::with_capacity(opts.unwrap_or(MANIFEST_DELETIONS_REWRITE_THRESHOLD as usize)),
    ))
  }

  fn read_exact(&mut self, _buf: &mut [u8]) -> Result<(), Self::Error> {
    unreachable!()
  }

  fn write_all(&mut self, data: &[u8]) -> Result<(), Self::Error> {
    self.extend_from_slice(data);
    Ok(())
  }

  fn flush(&mut self) -> Result<(), Self::Error> {
    Ok(())
  }

  fn sync_all(&self) -> Result<(), Self::Error> {
    Ok(())
  }

  fn truncate(&mut self, len: u64) -> Result<(), Self::Error> {
    Vec::truncate(self, len as usize);
    Ok(())
  }

  fn size(&self) -> Result<u64, Self::Error> {
    unreachable!()
  }
}