`dista.codec`

Turning task arguments and results into bytes and back.

encode and decode work on any type, chosen at compile time:

built-in scalars, Bool and String have fixed encodings (little-endian fixed width; String is an 8-byte length then its UTF-8 bytes);
arrow-mlake's RecordBatch is an 8-byte length then one Arrow IPC stream holding the schema and the batch, so columnar data crosses processes in Arrow's own format;
a type that conforms to Codec encodes itself;
any other struct is encoded field by field, in declaration order, by reflection.

Built-ins are recognised by reflect[T].name(), because Int or String can't adopt a dista trait. List and other generic containers aren't supported: reflection can't recover their element type. Wrap them in a type that implements Codec, or send columnar data as Arrow.

Both ends are the same binary, so there's no versioning or schema.

Traits

`Codec`

A type that writes and reads its own bytes.

`encode`

def encode(self, mut out: List[UInt8])

Appends this value's bytes to out.

`decode`

def decode(buf: Span[UInt8], mut pos: Int) -> Self

Reads a value starting at buf[pos] and advances pos past it.

Functions

`put_scalar`

def put_scalar[dt: DType](mut out: List[UInt8], v: Scalar[dt])

Appends v as its little-endian bytes.

`get_scalar`

def get_scalar[dt: DType](buf: Span[UInt8], mut pos: Int) -> Scalar[dt]

Reads a little-endian scalar at buf[pos] and advances pos.

`encode`

def encode[T: AnyType](ref value: T, mut out: List[UInt8])

Appends the bytes of value to out.

`decode`

def decode[T: Movable](buf: Span[UInt8], mut pos: Int) -> T

Reads a T starting at buf[pos] and advances pos past it.