Struct arrow_flight::sql::Any

pub struct Any {
    pub type_url: String,
    pub value: Bytes,
}

An implementation of the protobuf Any message type

Encoded protobuf messages are not self-describing, nor contain any information on the schema of the encoded payload. Consequently to decode a protobuf a client must know the exact schema of the message.

This presents a problem for loosely typed APIs, where the exact message payloads are not enumerable, and therefore cannot be enumerated as variants in a oneof.

One solution is Any where the encoded payload is paired with a type_url identifying the type of encoded message, and the resulting combination encoded.

Clients can then decode the outer Any, inspect the type_url and if it is a type they recognise, proceed to decode the embedded message value

Fields

type_url: String

A URL/resource name that uniquely identifies the type of the serialized protocol buffer message. This string must contain at least one “/” character. The last segment of the URL’s path must represent the fully qualified name of the type (as in path/google.protobuf.Duration). The name should be in a canonical form (e.g., leading “.” is not accepted).

value: Bytes

Must be a valid serialized protocol buffer of the above specified type.

Implementations

impl Any

pub fn is<M: ProstMessageExt>(&self) -> bool

pub fn unpack<M: ProstMessageExt>(&self) -> Result<Option<M>, ArrowError>

pub fn pack<M: ProstMessageExt>(message: &M) -> Result<Any, ArrowError>

Trait Implementations

impl Clone for Any

fn clone(&self) -> Any

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Any

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

Formats the value using the given formatter.

impl Default for Any

fn default() -> Self

Returns the “default value” for a type.

impl Message for Any

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<B>(&self, buf: &mut B) -> Result<(), EncodeError>where
    B: BufMut,
    Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8, Global>where
    Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited<B>(&self, buf: &mut B) -> Result<(), EncodeError>where
    B: BufMut,
    Self: Sized,

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

fn encode_length_delimited_to_vec(&self) -> Vec<u8, Global>where
    Self: Sized,

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

fn decode<B>(buf: B) -> Result<Self, DecodeError>where
    B: Buf,
    Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited<B>(buf: B) -> Result<Self, DecodeError>where
    B: Buf,
    Self: Default,

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

fn merge<B>(&mut self, buf: B) -> Result<(), DecodeError>where
    B: Buf,
    Self: Sized,

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

fn merge_length_delimited<B>(&mut self, buf: B) -> Result<(), DecodeError>where
    B: Buf,
    Self: Sized,

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

impl PartialEq<Any> for Any

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

This method tests for self and other values to be equal, and is used by ==.

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

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

impl StructuralPartialEq for Any