Module encdec::decode

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Expand description

Decode traits and helper macros

Example

#[derive(Debug, PartialEq)]
struct SomethingOwned {
    a: u8,
    b: u16,
    c: [u8; 3],
}

/// [`DecodeOwned`] implementation for self-contained types.
impl DecodeOwned for SomethingOwned {
    type Output = Self;
    type Error = Error;

   /// Decode object from provided buffer, returning object and decoded
   /// length on success
   fn decode_owned(buff: &[u8]) -> Result<(Self::Output, usize), Self::Error> {
        let mut index = 0;

        let a = buff[0];
        index += 1;

        let b = buff[1] as u16 | (buff[2] as u16) << 8;
        index += 2;

        let mut c = [0u8; 3];
        c.copy_from_slice(&buff[3..][..3]);
        index += 3;

        Ok((Self{a, b, c}, index))
   }
}
#[derive(Debug, PartialEq)]
struct SomethingBorrowed<'a> {
    a: u8,
    l: u16,
    c: &'a [u8],
}

/// Base [`Decode`] implementation, lifetime support for views
/// into borrowed buffers. If you don't need this, see [`DecodeOwned`].
impl <'a>Decode<'a> for SomethingBorrowed<'a> {
    type Output = SomethingBorrowed<'a>;
    type Error = Error;

   /// Decode object from provided buffer, returning object and decoded
   /// length on success
   fn decode(buff: &'a [u8]) -> Result<(Self::Output, usize), Self::Error> {
        let mut index = 0;

        let a = buff[0];
        index += 1;

        // using `l` as the length of `c`
        let l = buff[1] as u16 | (buff[2] as u16) << 8;
        index += 2;

        let c = &buff[index..][..l as usize];

        Ok((Self{a, l, c}, index))
   }
}

Structs

  • DecodeIter
    Helper type for parsing lists of decodable objects (with internal length delimiters)

Traits

  • Decode
    Decode trait implemented for binary decodable objects
  • DecodeExt
    Extensions to Decode trait for decodable objects
  • DecodeOwned
    Decode trait implemented for owned types
  • DecodePrefixed
    Decode helper trait for fields with length prefixes
  • DecodedTagged
    Decode helper trait for for fields with external length tags (length must be specified via #[encdec(length=...)] macro)

Derive Macros