rama-utils 0.2.0-alpha.9

utilities crate for rama
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

/// A helper function that unpacks a sequence of 2 bytes found in the buffer with
/// starting at the given offset, into a u16.
///
/// # Examples
///
/// ```
/// use rama_utils::octets::unpack_octets_as_u16;
/// let buf: [u8; 2] = [0, 1];
/// assert_eq!(1u16, unpack_octets_as_u16(&buf, 0));
/// ```
///
/// # Panics
///
/// In case the buffer is too small.
#[inline]
pub fn unpack_octets_as_u16(buf: &[u8], offset: usize) -> u16 {
    ((buf[offset] as u16) << 8) | (buf[offset + 1] as u16)
}

/// A helper function that unpacks a sequence of 4 bytes found in the buffer with
/// starting at the given offset, into a u32.
///
/// # Examples
///
/// ```
/// use rama_utils::octets::unpack_octets_as_u32;
/// let buf: [u8; 4] = [0, 0, 0, 1];
/// assert_eq!(1u32, unpack_octets_as_u32(&buf, 0));
/// ```
///
/// # Panics
///
/// In case the buffer is too small.
#[inline]
pub fn unpack_octets_as_u32(buf: &[u8], offset: usize) -> u32 {
    ((buf[offset] as u32) << 24)
        | ((buf[offset + 1] as u32) << 16)
        | ((buf[offset + 2] as u32) << 8)
        | (buf[offset + 3] as u32)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_unpack_octets_as_u16() {
        let buf: [u8; 2] = [0, 1];
        assert_eq!(1u16, unpack_octets_as_u16(&buf, 0));
    }

    #[test]
    fn test_unpack_octets_as_u32() {
        let buf: [u8; 4] = [0, 0, 0, 1];
        assert_eq!(1u32, unpack_octets_as_u32(&buf, 0));
    }
}