Trait bytecodec::Encode[−][src]

pub trait Encode {
    type Item;
    fn encode(&mut self, buf: &mut [u8], eos: Eos) -> Result<usize>;

    fn start_encoding(&mut self, item: Self::Item) -> Result<()>;

    fn requiring_bytes(&self) -> ByteCount;

    fn is_idle(&self) -> bool { ... }
}
Expand description

This trait allows for encoding items into a byte sequence incrementally.

Associated Types

The type of items to be encoded.

Required methods

Encodes the items in the encoder and writes the encoded bytes to the given buffer.

It returns the number of bytes written to the given buffer.

If the encoded bytes are larger than the length of buf, the encoder must consume as many bytes in the buffer as possible.

The completion of the encoding can be detected by using is_idle method.

If self.is_idle() returns false but the number of written bytes in the last encode invocation is smaller than the length of buf, it means the encoder has been suspended its work in any reasons. In that case the encoder may require some instructions from clients to resume the work, but its concrete method is beyond the scope of this trait.

The encoded bytes that could not be written to the given buffer is held by the encoder until the next invocation of the encode method.

Errors

Encoders return the following kinds of errors as necessary:

  • ErrorKind::InvalidInput:
    • An item that the encoder could not encode was passed
  • ErrorKind::UnexpectedEos:
    • The output byte stream has reached the end in the middle of an encoding process
  • ErrorKind::InconsistentState:
    • The state of the encoder bocame inconsistent
    • This means the implementation contains a bug
  • ErrorKind::Other:
    • Other errors has occurred

Tries to start encoding the given item.

If the encoder has no items to be encoded and the passed item is valid, it must accept the item.

Errors

  • ErrorKind::EncoderFull:
    • The encoder currently cannot accept any more items
  • ErrorKind::InvalidInput:
    • An invalid item was passed
  • ErrorKind::InconsistentState:
    • The state of the encoder bocame inconsistent
    • This means the implementation contains a bug
  • ErrorKind::Other:
    • Other errors has occurred

Returns the number of bytes required to encode all the items in the encoder.

If there are no items to be encoded, the encoder must return ByteCount::Finite(0).

Provided methods

Returns true if there are no items to be encoded in the encoder, otherwise false.

The default implementation returns the result of self.requiring_bytes() == ByteCount::Finite(0).

Implementations on Foreign Types

Implementors