Struct Header

pub struct Header {
    pub name: Bytes,
    pub value: Bytes,
}

Headers add structured information to a record as name-value pairs.

Header names cannot be empty, with the exception of “command messages” that are interpreted by S2. A command message is signalled by a sole header with empty name. The header value represents an operation, and the record body acts as a payload for the command. S2 client SDKs provide high-level APIs for command messages, and advanced users may also create them directly.

Valid operations are as follows:

• fence with an upto 16 byte payload to set a fencing token. An empty payload clears the token. Fencing is strongly consistent, and subsequent appends that specify a fencing token will be rejected if it does not match.
• trim with exactly 8 big-endian bytes as payload representing the desired earliest sequence number. This sequence number is only allowed to advance, and any regression will be ignored. Trimming is eventually consistent, and trimmed records may be visible for a brief period.

Fields

name: Bytes

Header name blob.

value: Bytes

Header value blob.

Implementations

impl Header

pub fn new(name: impl Into<Bytes>, value: impl Into<Bytes>) -> Self

Create a new header from name and value.

pub fn from_value(value: impl Into<Bytes>) -> Self

Create a new header from value.

Trait Implementations

impl Clone for Header

fn clone(&self) -> Header

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Header

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

Formats the value using the given formatter.

impl PartialEq for Header

fn eq(&self, other: &Header) -> 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 Eq for Header

impl StructuralPartialEq for Header