Crate urpc

uRPC (pronounced micro RPC) is a simple and lightweight RPC framework designed with embedded systems in mind. The server side works in a heapless environment with no_std and is supposed to use very low resources. The current client side implementation requires std.

Features

• ✓ Support for 256 different methods.
• ✓ Low level primitives for the server side regarding request parsing and reply serializing.
• ✓ Single argument of any sedre::Serialize + serde::DeserializeOwned type.
• ✓ Optional byte buffer for the argument that doesn’t involve any buffer copy.
  • This feature is designed to optimize the transfer of bytes between client and server minimizing the amount of used memory in the server.
• ✓ Single return value of any sedre::Serialize + serde::DeserializeOwned type.
• ✓ Optional byte buffer for the reply that doesn’t involve any buffer copy.
  • This feature is designed to optimize the transfer of bytes between client and server minimizing the amount of used memory in the client.
• ✗ Methods can return custom errors.
• ✗ Asyncrhonous methods.
  • ✗ Support for holding 255 async uncompleted requests.
• ✗ Stream methods.

Packet format

• The request packet consists of a 7 byte header, an optional body and an optional byte buffer.
• The reply packet consists of a 6 byte header, an optional body and an optional byte buffer.

Header Format

Request

length	desc
8b	method index
8b	channel id
8b	options
16b	body length (little endian)
16b	optional buffer length (little endian)

Reply

length	desc
8b	channel id
8b	options
16b	body length (little endian)
16b	optional buffer length (little endian)

Usage

The best way to use this library is by using the macros server_requets and client_requests. You can see complete examples in the documentation: server_requests, client_requests.

Modules

client

Client side implementation

consts

Constant parameters

server

Server side implementation

Macros

client_requests

Macro that builds the required types to make calls via RPC from the client.

rpc_client_io

rpc_client_io_fn

server_requests

server_requests_variant

Macro that builds the required types to handle calls via RPC from the server.

Structs

OptBufNo

Indicate that the RPC Call doesn’t contain an optional buffer.

OptBufYes

Indicate that the RPC Call contains an optional buffer.

Opts

Options of a request/reply packet

ReplyHeader

Header of a reply packet

RequestHeader

Header of a request packet

Traits

OptBuf

Trait used to allow building RPC calls with optional buffer.