Trait HeaderValue 

pub trait HeaderValue: Sealed + Sized {
    const KIND: HeaderValueKind;
    const ALWAYS_FITS_WIRE_LENGTH: bool = false;

    // Required methods
    fn to_map_value(&self) -> CheetahString;
    fn encoded_len(&self) -> usize;
    fn write_ascii(&self, out: &mut BytesMut);
    fn decode(
        raw: &str,
        context: HeaderFieldContext,
    ) -> Result<Self, ProtocolContractViolation>;

    // Provided method
    fn write_json_string(&self, out: &mut BytesMut) { ... }
}

A protocol-approved request-header wire value.

Implementations must keep encoded_len and write_ascii byte-for-byte consistent. This trait is sealed: new wire types require an explicit implementation and compatibility review in rocketmq-protocol.

Required Associated Constants

const KIND: HeaderValueKind

Static value category used by generated schemas and diagnostics.

Provided Associated Constants

const ALWAYS_FITS_WIRE_LENGTH: bool = false

Whether every value of this type fits Java’s signed 32-bit wire length.

Required Methods

fn to_map_value(&self) -> CheetahString

Produces the owned value required by a crate::HeaderMap.

fn encoded_len(&self) -> usize

Returns the exact number of bytes written by Self::write_ascii.

fn write_ascii(&self, out: &mut BytesMut)

Appends the canonical UTF-8/ASCII wire representation without a temporary String for scalar values.

fn decode( raw: &str, context: HeaderFieldContext, ) -> Result<Self, ProtocolContractViolation>

Decodes a complete map value according to the field context.

Errors

Returns ProtocolContractViolation::InvalidValue for malformed or overflowing scalar values, or ProtocolContractViolation::JavaRange when an unsigned value exceeds its field’s declared signed Java range. Errors never retain raw.

Provided Methods

fn write_json_string(&self, out: &mut BytesMut)

Appends the canonical extension-field value as a JSON string.

Scalar implementations use their allocation-free ASCII form. Text implementations override this method to apply JSON escaping.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl HeaderValue for BoundaryType

const KIND: HeaderValueKind = HeaderValueKind::BoundaryType

const ALWAYS_FITS_WIRE_LENGTH: bool = true

fn to_map_value(&self) -> CheetahString

fn encoded_len(&self) -> usize

fn write_ascii(&self, out: &mut BytesMut)

fn decode( raw: &str, _context: HeaderFieldContext, ) -> Result<Self, ProtocolContractViolation>

impl HeaderValue for CheetahString

const KIND: HeaderValueKind = HeaderValueKind::String

const ALWAYS_FITS_WIRE_LENGTH: bool = false

fn to_map_value(&self) -> CheetahString

fn encoded_len(&self) -> usize

fn write_ascii(&self, out: &mut BytesMut)

fn write_json_string(&self, out: &mut BytesMut)

fn decode( raw: &str, _context: HeaderFieldContext, ) -> Result<Self, ProtocolContractViolation>

impl HeaderValue for String

const KIND: HeaderValueKind = HeaderValueKind::String

const ALWAYS_FITS_WIRE_LENGTH: bool = false

fn to_map_value(&self) -> CheetahString

fn encoded_len(&self) -> usize

fn write_ascii(&self, out: &mut BytesMut)

fn write_json_string(&self, out: &mut BytesMut)

fn decode( raw: &str, _context: HeaderFieldContext, ) -> Result<Self, ProtocolContractViolation>

impl HeaderValue for bool

const KIND: HeaderValueKind = HeaderValueKind::Bool

const ALWAYS_FITS_WIRE_LENGTH: bool = true

fn to_map_value(&self) -> CheetahString

fn encoded_len(&self) -> usize

fn write_ascii(&self, out: &mut BytesMut)

fn decode( raw: &str, context: HeaderFieldContext, ) -> Result<Self, ProtocolContractViolation>

impl HeaderValue for i32

const KIND: HeaderValueKind = HeaderValueKind::I32

const ALWAYS_FITS_WIRE_LENGTH: bool = true

fn to_map_value(&self) -> CheetahString

fn encoded_len(&self) -> usize

fn write_ascii(&self, out: &mut BytesMut)

fn decode( raw: &str, context: HeaderFieldContext, ) -> Result<Self, ProtocolContractViolation>

impl HeaderValue for i64

const KIND: HeaderValueKind = HeaderValueKind::I64

const ALWAYS_FITS_WIRE_LENGTH: bool = true

fn to_map_value(&self) -> CheetahString

fn encoded_len(&self) -> usize

fn write_ascii(&self, out: &mut BytesMut)

fn decode( raw: &str, context: HeaderFieldContext, ) -> Result<Self, ProtocolContractViolation>

impl HeaderValue for u32

const KIND: HeaderValueKind = HeaderValueKind::U32

const ALWAYS_FITS_WIRE_LENGTH: bool = true

fn to_map_value(&self) -> CheetahString

fn encoded_len(&self) -> usize

fn write_ascii(&self, out: &mut BytesMut)

fn decode( raw: &str, context: HeaderFieldContext, ) -> Result<Self, ProtocolContractViolation>

impl HeaderValue for u64

const KIND: HeaderValueKind = HeaderValueKind::U64

const ALWAYS_FITS_WIRE_LENGTH: bool = true

fn to_map_value(&self) -> CheetahString

fn encoded_len(&self) -> usize

fn write_ascii(&self, out: &mut BytesMut)

fn decode( raw: &str, context: HeaderFieldContext, ) -> Result<Self, ProtocolContractViolation>

Implementors