Enum MessageHeader 

#[non_exhaustive]
pub enum MessageHeader {
    Type0 {
        timestamp: u32,
        message_length: u32,
        message_type_id: u8,
        message_stream_id: u32,
    },
    Type1 {
        timestamp_delta: u32,
        message_length: u32,
        message_type_id: u8,
    },
    Type2 {
        timestamp_delta: u32,
    },
    Type3,
}

Chunk Message Header: one of 4 formats selected by Fmt (§5.3.1.2), carrying decreasing field sets — each format after Type 0 inherits the fields it omits from the preceding chunk on the same chunk stream.

Reassembling that “preceding chunk” state (so Type 1/2/3 headers can be resolved to absolute values) is a stateful job for the chunk-stream reassembler (#738 Task 4), not this header type. In particular, a Type 3 header carrying zero bytes here does not by itself tell you whether an Extended Timestamp follows it on the wire: per §5.3.1.3, a Type 3 chunk carries the 4-byte Extended Timestamp when — and only when — the most recent Type 0/1/2 chunk on the same csid itself used one. Deciding that requires exactly that per-csid state, so MessageHeader::parse never consumes an Extended Timestamp for Fmt::Type3; the reassembler must apply this rule itself once it is tracking that state.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Type0

Type 0 (§5.3.1.2.1, 11 bytes on the wire before any Extended Timestamp). MUST be used at the start of a chunk stream and whenever the stream timestamp goes backward.

Fields

timestamp: u32

Absolute timestamp of the message (already resolved from any Extended Timestamp).

message_length: u32

Length in bytes of the whole message (not the chunk payload).

message_type_id: u8

Message type id (§6/§7.1).

message_stream_id: u32

Message stream id. The wire encoding of this field alone is little-endian (§5.3.1.2.1).

Type1

Type 1 (§5.3.1.2.2, 7 bytes before any Extended Timestamp). No message stream id — inherits the preceding chunk’s.

Fields

timestamp_delta: u32

Delta from the previous chunk’s timestamp on this csid (already resolved from any Extended Timestamp).

message_length: u32

Length in bytes of the whole message.

message_type_id: u8

Message type id (§6/§7.1).

Type2

Type 2 (§5.3.1.2.3, 3 bytes before any Extended Timestamp). Neither stream id nor message length included — both inherited.

Fields

timestamp_delta: u32

Delta from the previous chunk’s timestamp on this csid (already resolved from any Extended Timestamp).

Type3

Type 3 (§5.3.1.2.4, 0 bytes). Stream id, message length, message type id, and timestamp delta are all inherited from the preceding chunk on the same csid.

Implementations

impl MessageHeader

pub fn parse(fmt: Fmt, bytes: &[u8]) -> Result<(Self, usize), RtmpError>

Parse the message header that follows a BasicHeader carrying fmt. Returns the parsed variant and the number of bytes consumed from bytes — the fixed per-fmt header length, plus 4 more if a Type 0/1/2 field’s 24-bit value read exactly EXTENDED_TIMESTAMP_MARKER (in which case the real, unresolved value is read from the following 4-byte big-endian Extended Timestamp — see §5.3.1.3).

Errors

RtmpError::BufferTooShort if bytes does not hold the full fixed header (and, when signalled, the Extended Timestamp).

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 Copy for MessageHeader

impl Debug for MessageHeader

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

Formats the value using the given formatter.

impl Eq for MessageHeader

impl PartialEq for MessageHeader

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for MessageHeader

type Error = RtmpError

The error type this implementer returns (usually the same as the corresponding Parse impl, but need not be).

fn serialized_len(&self) -> usize

Number of bytes serialize_into will write.

fn serialize_into(&self, buf: &mut [u8]) -> Result<usize, RtmpError>

Write the serialised form into buf. Returns the number of bytes written (always equal to serialized_len()).

fn to_bytes(&self) -> Vec<u8>

where Self::Error: Debug,

Convenience: allocate a Vec and serialise into it.

impl StructuralPartialEq for MessageHeader