Crate fidl_next_protocol 

Protocol support for FIDL.

This crate provides a number of types and traits related to FIDL protocols. These types and traits are all “untyped” - that is, they do not know about the specific types of the FIDL messages being sent and received. They only deal with protocol-layer semantics: requests and responses, clients and servers, and transports.

Transports

This crate uses “transport” to refer to the specific object which moves bytes and handles from a sender to a receiver. For example, this crate may refer to a channel, socket, file, or other byte source/sink as a “transport”. This differs from the @transport(..) annotation in the FIDL language, which can be added to protocols.

FIDL transports implement the Transport trait. This trait defines several key properties:

• The associated Shared and Exclusive types.
• The buffer types for sending and receiving data.
• The async methods for sending and receiving data with those buffers.

All types in the protocol layer are generic over the transport, making it easy to add support for new types of transports.

By default, both sending and receiving data with a transport are asynchronous operations. However, transports may support synchronous send operations by implementing the NonBlockingTransport trait. This trait allows users to replace .await-ing a send operation with .send_immediately(), which synchronously completes the send future.

This crate provides an implementation of Transport for Fuchsia channels.

Clients and servers

ClientDispatchers and ServerDispatchers are constructed from a transport, and can be run with a corresponding ClientHandler or ServerHandler. The dispatcher will then run its event loop to receive data through the transport. Client dispatchers use their handlers to handle incoming events, and coordinate with any Clients to route two-way method responses to waiting futures. Server dispatchers use their handlers to handle incoming one-way and two-way method requests, but do not generally coordinate with their associated Servers.

Clients and Servers implement Clone, and should be cloned to interact with the connection from multiple locations.

Modules

fuchsia

Fuchsia-specific FIDL protocol extensions.

mpsc

A basic Transport implementation based on MPSC channels.

Structs

Client

A client endpoint.

ClientDispatcher

A dispatcher for a client endpoint.

MessageHeaderFlags0

The transactional message header flags in byte 0.

MessageHeaderFlags1

The transactional message header flags in byte 1.

MessageHeaderFlags2

The transactional message header flags in byte 2.

RespondFuture

A future which responds to a request over a connection.

Responder

A responder for a two-way message.

SendFuture

A future which sends an encoded message to a connection.

Server

A server endpoint.

ServerDispatcher

A dispatcher for a server endpoint.

TwoWayRequestFuture

A future for a sending a two-way FIDL message.

TwoWayResponseFuture

A future for a pending response to a two-way message.

WireEpitaph

A FIDL protocol epitaph.

WireFlexible

A flexible FIDL response.

WireFlexibleResult

A flexible FIDL result.

WireFrameworkError

An internal framework error.

WireMessageHeader

A FIDL protocol message header

Enums

Flexibility

The flexibility of a method.

Flexible

A flexible FIDL response.

FlexibleResult

A flexible FIDL result.

FrameworkError

An internal framework error.

ProtocolError

Errors that can be produced by FIDL clients and servers.

Constants

MAGIC_NUMBER

The magic number indicating FIDL protocol compatibility.

Traits

ClientHandler

A type which handles incoming events for a client.

NonBlockingTransport

A transport layer which can send messages without blocking.

ServerHandler

A type which handles incoming events for a server.

ServiceConnector

A member connector for a FIDL service.

ServiceHandler

A type which handles incoming service connections for a server.

Transport

A transport layer which can send and receive messages.

Functions

decode_epitaph

Parses the epitaph error from the given buffer.

decode_header

Parses the transaction ID and ordinal from the given buffer.

encode_epitaph

Encodes an epitaph into the given buffer.

encode_header

Encodes a message into the given buffer.