Crate embedded_jsonrpc

Source
Expand description

§JSON-RPC for Embedded Systems

This crate provides a JSON-RPC server implementation for embedded systems.

§Features

  • #![no_std] Support: Fully compatible with environments lacking a standard library.
  • Predictable Memory Usage: Zero dynamic allocation with statically sized buffers.
  • Async: Non-blocking I/O with embedded-io-async.
  • Client Compatibility: Uses LSP style framing for JSON-RPC messages.
  • Error Handling: Adheres to JSON-RPC standards with robust error reporting.

§Example Usage

§Create an RPC Server

use embedded_jsonrpc::{RpcError, RpcResponse, RpcServer, RpcHandler, JSONRPC_VERSION, DEFAULT_STACK_SIZE};
use embedded_jsonrpc::stackfuture::StackFuture;

struct MyHandler;

impl RpcHandler for MyHandler {
   fn handle<'a>(&self, id: Option<u64>, _method: &'a str, _request_json: &'a [u8], response_json: &'a mut [u8]) -> StackFuture<'a, Result<usize, RpcError>, DEFAULT_STACK_SIZE> {
      StackFuture::from(async move {
         let response: RpcResponse<'static, ()> = RpcResponse {
           jsonrpc: JSONRPC_VERSION,
           error: None,
           result: None,
           id,
         };
        Ok(serde_json_core::to_slice(&response, response_json).unwrap())
     })
  }
}

let mut server: RpcServer<'_> = RpcServer::new();
server.register_method("echo", &MyHandler);

§Serve Requests

ⓘ
let mut stream: YourAsyncStream = YourAsyncStream::new();
server.serve(&mut stream).await.unwrap();

§License

This crate is licensed under the Mozilla Public License 2.0 (MPL-2.0). See the LICENSE file for more details.

§References

Modules§

  • stackfuture
    This crate defines a StackFuture wrapper around futures that stores the wrapped future in space provided by the caller. This can be used to emulate dyn async traits without requiring heap allocation.

Structs§

Enums§

Constants§

  • DEFAULT_HANDLER_TIMEOUT_MS
    Default handler timeout in milliseconds. This is the maximum time allowed for a handler to process a request.
  • DEFAULT_MAX_CLIENTS
    Default maximum number of clients.
  • DEFAULT_MAX_HANDLERS
    Maximum number of registered RPC methods.
  • DEFAULT_MAX_MESSAGE_LEN
    Maximum length of a JSON-RPC message (including headers). Default to the largest message that’ll fit in a single Ethernet frame.
  • DEFAULT_STACK_SIZE
    Default stack size for futures. This is a rough estimate and will need to be adjusted based on the complexity of your handlers.
  • DEFAULT_WRITE_TIMEOUT_MS
    Default write timeout in milliseconds. This is the maximum time allowed for writing to the stream.
  • JSONRPC_VERSION
    JSON-RPC Version Currently only supports version 2.0 https://www.jsonrpc.org/specification

Traits§