Struct DispatchOutputMapping 

pub struct DispatchOutputMapping {
    pub indices: Vec<u32>,
    pub types: Vec<TypePair>,
}

The method to map the upstream columns in the dispatcher before dispatching.

• For intra-job exchange, typically the upstream and downstream columns are the same. indices will be 0..len and types will be empty.

• For inter-job exchange,

  • if the downstream only requires a subset of the upstream columns, indices will be the indices of the required columns in the upstream columns.
  • if some columns are added to the upstream, indices will help to maintain the same schema from the view of the downstream.
  • if some columns are altered to different (composite) types, types will be used to convert the upstream columns to the downstream columns to maintain the same schema.

Fields

indices: Vec<u32>

Indices of the columns to output.

types: Vec<TypePair>

Besides the indices, we may also need to convert the types of some columns.

• If no type conversion is needed, this field will be empty.
• If type conversion is needed, this will have the same length as indices. Only columns with type conversion will have upstream and downstream field set.

Implementations

impl DispatchOutputMapping

pub fn get_indices(&self) -> &Vec<u32>

pub fn get_types(&self) -> &Vec<TypePair>

impl DispatchOutputMapping

pub fn identical(len: usize) -> Self

Create a mapping that forwards all columns.

pub fn simple(indices: Vec<u32>) -> Self

Create a mapping that forwards columns with given indices, without type conversion.

pub fn into_simple_indices(self) -> Vec<u32>

Assert that this mapping does not involve type conversion and return the indices.

Trait Implementations

impl Clone for DispatchOutputMapping

fn clone(&self) -> DispatchOutputMapping

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DispatchOutputMapping

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for DispatchOutputMapping

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for DispatchOutputMapping

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Message for DispatchOutputMapping

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode(&self, buf: &mut impl BufMut) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited( &self, buf: &mut impl BufMut, ) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl PartialEq for DispatchOutputMapping

fn eq(&self, other: &DispatchOutputMapping) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for DispatchOutputMapping

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for DispatchOutputMapping