Struct grpcio::Metadata

#[repr(C)]
pub struct Metadata(_);

A collection of metadata entries that can be exchanged during a call.

gRPC supports these types of metadata:

• Request headers

  They are sent by the client at the beginning of a remote call before any request messages are sent.

• Response headers

  They are sent by the server at the beginning of a remote call handler before any response messages are sent.

• Response trailers

  They are sent by the server at the end of a remote call along with resulting call status.

Metadata value can be ascii string or bytes. They are distinguish by the key suffix, key of bytes value should have suffix '-bin'.

Methods

impl Metadata

pub fn len(&self) -> usize

Returns the count of metadata entries.

pub fn is_empty(&self) -> bool

Returns true if there is no metadata entries.

pub fn get(&self, index: usize) -> Option<(&str, &[u8])>

Returns the metadata entry at the index.

None is returned if out of bound.

Important traits for MetadataIter<'a>

impl<'a> Iterator for MetadataIter<'a> type Item = (&'a str, &'a [u8]);

pub fn iter(&self) -> MetadataIter

Returns an iterator over the metadata entries.

Trait Implementations

impl Drop for Metadata

fn drop(&mut self)

Executes the destructor for this type.

impl Clone for Metadata

fn clone(&self) -> Metadata

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a> IntoIterator for &'a Metadata

type IntoIter = MetadataIter<'a>

Which kind of iterator are we turning this into?

type Item = (&'a str, &'a [u8])

The type of the elements being iterated over.

Important traits for MetadataIter<'a>

impl<'a> Iterator for MetadataIter<'a> type Item = (&'a str, &'a [u8]);

fn into_iter(self) -> MetadataIter<'a>

Creates an iterator from a value.