Module message 

Draft-23 control message encoding and decoding.

• The Message Length is a vi64 (Section 9, Figure 6), bounded by the receiver’s MAX_CONTROL_MESSAGE_SIZE (Section 9.1.8), 65535 unless the receiver advertised more. ControlMessage::decode and ControlMessage::encode use that default; ControlMessage::decode_with_limit and ControlMessage::encode_with_limit take the limit.
• FETCH is answered by REQUEST_OK; type 0x18 is reserved (Section 9, Table 5).
• REQUEST_ERROR ends in Error Details, Key-Value-Pairs (Section 9.4.1).
• NAMESPACE carries a parameter block (Section 9.15, Figure 20).
• FILL_PARAMETERS (0x23) is a parameter count followed by that many parameters, with no length (Section 9.19.15).
• PAUSED (0x11, Section 9.19.18) and SUBSCRIBE_TRACKS_ID (0x36, Section 9.19.21).

Every section, table and figure reference in this module is draft-23’s own.

Re-exports

use crate::auth_token::AuthorizationToken; 🔒

use crate::auth_token::AUTH_TOKEN_PARAMETER; 🔒

use crate::error::MAX_FULL_TRACK_NAME_LENGTH; 🔒

pub use crate::error::CodecError;

pub use crate::error::MAX_GOAWAY_URI_LENGTH;

pub use crate::error::MAX_MESSAGE_LENGTH;

pub use crate::error::MAX_NAMESPACE_TUPLE_SIZE;

pub use crate::error::MAX_REASON_PHRASE_LENGTH;

use crate::kvp::KeyValuePair; 🔒

use crate::kvp::KvpError; 🔒

use crate::kvp::KvpValue; 🔒

use crate::kvp::MAX_KVP_VALUE_LEN; 🔒

use crate::varint::Moqt18 as Wire; 🔒

use crate::varint::VarInt; 🔒

use bytes::Buf; 🔒

use bytes::BufMut; 🔒

use crate::types::*; 🔒

Modules

error_detail_types

The Error Detail types draft-23 Section 16.11, Table 19 assigns.

location_filter_types

The Location Filter Type values draft-23 Section 9.19.9 assigns, named as Table 6 names them.

publish_done_codes

Numeric values for the PublishDone fields.

request_error_codes

REQUEST_ERROR error codes with dedicated meaning.

Structs

Fetch

FETCH (0x16), Section 9.11, Figure 17.

GoAway

GOAWAY (0x10). There is no Request ID field, so the control-stream and request-stream forms are identical on the wire.

Namespace

NAMESPACE (0x08), Section 9.15, Figure 20: a Track Namespace Suffix, then a parameter block.

NamespaceDone

Publish

PublishDone

PUBLISH_DONE (0x0B).

PublishNamespace

PublishSkipped

PUBLISH_SKIPPED (0x0F): a track namespace suffix, then a track name.

PublishStateNotify

PUBLISH_STATE_NOTIFY (0x22), Section 9.10, Figure 16.

Redirect

The value of a REDIRECT Error Detail (Section 9.4.2.1).

RequestError

REQUEST_ERROR (0x05), Section 9.4.1, Figure 10.

RequestOk

REQUEST_OK (0x07), the response to PUBLISH, FETCH, REQUEST_UPDATE, TRACK_STATUS, SUBSCRIBE_NAMESPACE, SUBSCRIBE_TRACKS and PUBLISH_NAMESPACE (Section 9.3).

RequestUpdate

Setup

Unified SETUP (0x2F00).

Subscribe

SubscribeNamespace

SUBSCRIBE_NAMESPACE (0x50). Subscribes to NAMESPACE / NAMESPACE_DONE advertisements for namespaces matching namespace_prefix.

SubscribeOk

SUBSCRIBE_OK (0x04).

SubscribeTracks

SUBSCRIBE_TRACKS (0x51). Subscribes to PUBLISH messages for tracks whose namespace matches namespace_prefix.

TrackStatus

Enums

ControlMessage

MessageType

The control message types draft-23 Section 9, Table 5 assigns.

ParamEncoding 🔒

How a parameter value is encoded on the wire.

RequestOkKind

The request a RequestOk answers, named by Section 1.5’s shorthand.

Constants

AUTHORIZATION_TOKEN 🔒

AUTHORIZATION TOKEN, Parameter Type 0x03.

DEFAULT_MAX_CONTROL_MESSAGE_SIZE

The MAX_CONTROL_MESSAGE_SIZE an endpoint uses for its peer until it has the peer’s SETUP, and when the SETUP carries none.

FILL_PARAMETERS

The FILL_PARAMETERS parameter type, draft-23 Section 9.19.15.

FILL_PARAMETERS_ALLOWED 🔒

The parameter types draft-23 Section 9.19.15, Table 7 permits inside a FILL_PARAMETERS value, in ascending order. “An endpoint that receives a parameter inside FILL_PARAMETERS that is not listed above MUST close the session with INVALID_PARAMETER.”

IMMUTABLE_PROPERTIES 🔒

Immutable Properties, Property Type 0xB.

KNOWN_SETUP_OPTIONS 🔒

The Setup Option types this draft defines.

LOCATION_FILTER

The LOCATION_FILTER parameter type, draft-23 Section 9.19.9.

MAX_CONTROL_MESSAGE_SIZE_OPTION

The MAX_CONTROL_MESSAGE_SIZE Setup Option type, Section 9.1.8.

REPEATABLE_SETUP_OPTION 🔒

The one Setup Option whose definition allows more than one instance.

Functions

add_delta 🔒

Add a delta to the previous delta-encoded key.

check_authorization_tokens 🔒

Hold every AUTHORIZATION TOKEN parameter to the Token structure it names.

check_error_details 🔒

Hold a REQUEST_ERROR’s Error Details to its Error Code.

check_error_details_to_send 🔒

The sender’s half of check_error_details, plus Section 9.4.2: “Senders MUST NOT repeat the same Error Detail type in a message unless the type’s definition explicitly allows multiple instances.” Only UNSUPPORTED_PROPERTY allows them, and a type this draft does not define is the caller’s to repeat or not.

check_full_track_name 🔒

Hold a namespace-plus-name pair to the Full Track Name cap.

check_location_filter_fields 🔒

Hold a decoded LOCATION_FILTER to the one arithmetic rule draft-23 states about it.

check_location_filters 🔒

Hold every LOCATION_FILTER and FILL_PARAMETERS parameter to the structure its own type names.

check_parameter_scope 🔒

Refuse a message carrying a Message Parameter its own definition does not place there (Section 9.19.1).

check_setup_token_aliases 🔒

Refuse a SETUP token that names an Alias with DELETE or USE_ALIAS.

check_track_name 🔒

Refuse an empty Track Name.

check_track_property_values 🔒

Refuse a Track Property whose value falls outside the range its type allows, wherever in the list it is carried.

decode_fill_parameters

Decode the parameters a FILL_PARAMETERS value carries.

decode_kvp_delta 🔒

Decode delta-encoded KVPs with even/odd convention (for setup options and track properties). Read until buffer is exhausted.

decode_location_filter

Decode a draft-23 LOCATION_FILTER value into its Location Filter Type and the fields that type names.

decode_max_control_message_size

The value of a MAX_CONTROL_MESSAGE_SIZE option: the one vi64 its bytes hold.

decode_parameter_value 🔒

Read one parameter’s value in the shape its type names.

decode_parameters 🔒

Decode a count-prefixed list of parameters with delta-encoded types.

decode_property_list 🔒

Decode bytes as a run of Key-Value-Pairs, the shape of an Immutable Properties value (Section 10.7).

decode_setup_options 🔒

Decode the Setup Options of a SETUP message.

decode_track_properties 🔒

Decode the Track Properties that fill the tail of a control message.

encode_fill_parameters

Encode params as a FILL_PARAMETERS value, the inverse of decode_fill_parameters.

encode_kvp_delta 🔒

Encode delta-encoded KVPs with even/odd convention.

encode_max_control_message_size

The bytes of a MAX_CONTROL_MESSAGE_SIZE option carrying size.

encode_parameters 🔒

Encode a count-prefixed list of parameters with delta-encoded types.

encode_setup_options 🔒

Encode the Setup Options of a SETUP message.

encode_track_properties 🔒

Encode a control message’s Track Properties.

is_location_value 🔒

Whether bytes is exactly the wire form of a Location — two consecutive varints and nothing after them.

is_track_namespace_value 🔒

Whether bytes is exactly the wire form of a Track Namespace, with nothing after it. The same reasoning as is_location_value: the value goes out verbatim, so it has to be something this draft can read back.

location_filter_field_count

How many vi64 fields follow a Location Filter Type, or None for a type draft-23 does not assign.

max_control_message_size

The MAX_CONTROL_MESSAGE_SIZE a SETUP’s options advertise, or the default.

param_encoding 🔒

parameter_in_scope

Whether draft-23 lets Message Parameter key appear in message.

parameter_may_repeat 🔒

Whether draft-23 lets a message carry parameter type key more than once.

read_fill_parameters 🔒

Read one FILL_PARAMETERS value off buf: its Number of Parameters and that many parameters.

read_location_filter 🔒

Read one LOCATION_FILTER value off buf: the Location Filter Type, then exactly the fields that type names.

track_property_value_in_range 🔒

Whether value is inside the range draft-23 allows for a Track Property type that restricts one.

uint8_value_in_range 🔒

Whether value is inside the range draft-23 allows for a uint8-valued parameter.

write_fill_parameters 🔒

Write a FILL_PARAMETERS value: the count and the inner parameters, with no length ahead of them.

write_location_filter 🔒

Write a LOCATION_FILTER value in its minimal encoding: the type, then the fields, each the shortest vi64 that holds it.