Struct Metadata 

pub struct Metadata { /* private fields */ }

Metadata for one call. Keys are lowercase, as HTTP/2 requires.

Implementations

impl Metadata

pub fn new() -> Metadata

pub fn is_empty(&self) -> bool

pub fn len(&self) -> usize

pub fn insert(&mut self, key: &str, value: impl Into<String>) -> &mut Self

Set an ASCII value, replacing any existing entries for the key.

pub fn insert_bin(&mut self, key: &str, value: impl Into<Vec<u8>>) -> &mut Self

Set a binary value. The key must end in -bin, which is the gRPC signal that the value is base64 on the wire.

pub fn append(&mut self, key: &str, value: impl Into<String>) -> &mut Self

Add a value without removing existing ones — gRPC metadata is multi-valued.

pub fn remove(&mut self, key: &str)

pub fn get(&self, key: &str) -> Option<&str>

The first ASCII value for key.

pub fn get_bin(&self, key: &str) -> Option<&[u8]>

The first binary value for key.

pub fn iter(&self) -> impl Iterator<Item = (&str, &MetadataValue)>

pub fn to_headers(&self) -> Vec<(String, String)>

Render to wire headers, base64-encoding every -bin value.

pub fn from_headers(headers: &HashMap<String, String>) -> Metadata

Read wire headers back, base64-decoding -bin values. Framing headers are dropped: they describe the transport, not the call.

Trait Implementations

impl Clone for Metadata

fn clone(&self) -> Metadata

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Metadata

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

Formats the value using the given formatter.

impl Default for Metadata

fn default() -> Metadata

Returns the “default value” for a type.

impl Eq for Metadata

impl PartialEq for Metadata

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Metadata