Struct MessageHeader 

#[repr(C, packed(1))]
pub struct MessageHeader {
    pub block_length: u16,
    pub template_id: u16,
    pub schema_id: u16,
    pub version: u16,
}

Standard SBE message header (8 bytes).

The message header precedes every SBE message and contains:

• Block length: Size of the root block in bytes
• Template ID: Message type identifier
• Schema ID: Schema identifier
• Version: Schema version number

Wire Format

+0: blockLength  (u16, 2 bytes)
+2: templateId   (u16, 2 bytes)
+4: schemaId     (u16, 2 bytes)
+6: version      (u16, 2 bytes)

Fields

block_length: u16

Length of the root block in bytes.

template_id: u16

Message template identifier.

schema_id: u16

Schema identifier.

version: u16

Schema version number.

Implementations

impl MessageHeader

pub const ENCODED_LENGTH: usize = 8

Encoded length of the message header in bytes.

pub const fn new( block_length: u16, template_id: u16, schema_id: u16, version: u16, ) -> MessageHeader

Creates a new message header with the specified values.

Arguments

• block_length - Length of the root block in bytes
• template_id - Message template identifier
• schema_id - Schema identifier
• version - Schema version number

pub fn wrap<B>(buffer: &B, offset: usize) -> MessageHeader

where B: ReadBuffer + ?Sized,

Wraps a buffer and decodes the message header at the given offset.

Arguments

• buffer - Buffer to read from
• offset - Byte offset to start reading

Panics

Panics if the buffer is too short.

pub fn encode<B>(&self, buffer: &mut B, offset: usize)

where B: WriteBuffer + ?Sized,

Encodes the message header to the buffer at the given offset.

Arguments

• buffer - Buffer to write to
• offset - Byte offset to start writing

pub const fn message_size(&self) -> usize

Returns the total message size (header + block).

Trait Implementations

impl Clone for MessageHeader

fn clone(&self) -> MessageHeader

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MessageHeader

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

Formats the value using the given formatter.

impl Default for MessageHeader

fn default() -> MessageHeader

Returns the “default value” for a type.

impl PartialEq for MessageHeader

fn eq(&self, other: &MessageHeader) -> 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 Copy for MessageHeader

impl Eq for MessageHeader

impl StructuralPartialEq for MessageHeader