jsonrpce 0.1.0

JSON-RPC 2.0 for Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93

// syncronous stream. works with any reader and writer.
// this includes stdio, tcp, for testing etc

use std::{
    collections::HashMap,
    io::{BufRead, Write},
};

use serde_json::Value;

use crate::{Error, Request, Response, Transport};

pub type BoxedHandler<S> = Box<dyn Fn(&S, Value) -> Result<Value, Error> + Send + Sync>;

/// A generic sync transport that operates on any `BufRead` input and `Write` output.
pub struct Stream<R, W> {
    reader: R,
    writer: W,
}

impl<R, W> Stream<R, W>
where
    R: BufRead,
    W: Write,
{
    pub fn new(reader: R, writer: W) -> Self {
        Self { reader, writer }
    }
}

impl<C, R, W> Transport<C> for Stream<R, W>
where
    C: Send + Sync,
    R: BufRead,
    W: Write,
{
    type Handler = BoxedHandler<C>;

    type Output = ();
    type Error = std::io::Error;

    fn serve(
        mut self,
        ctx: C,
        handlers: HashMap<String, Self::Handler>,
    ) -> Result<Self::Output, Self::Error> {
        for line in self.reader.lines() {
            let line = line?;
            if line.trim().is_empty() {
                continue;
            }

            // Parse
            let req: Request = match serde_json::from_str(&line) {
                Ok(r) => r,
                Err(e) => {
                    let err = Response::error(None, Error::new(-32700, e.to_string()));
                    let json = serde_json::to_string(&err)?;
                    writeln!(self.writer, "{}", json)?;
                    self.writer.flush()?;
                    continue;
                }
            };

            // Validate Version
            if req.jsonrpc != "2.0" {
                let err = Response::error(req.id, Error::invalid_params("Version must be '2.0'"));
                writeln!(self.writer, "{}", serde_json::to_string(&err)?)?;
                self.writer.flush()?;
                continue;
            }

            // Find & Execute
            let response = if let Some(handler) = handlers.get(&req.method) {
                match handler(&ctx, req.params) {
                    Ok(res) => Response::success(req.id.clone(), res),
                    Err(e) => Response::error(req.id.clone(), e),
                }
            } else {
                Response::error(req.id.clone(), Error::method_not_found(&req.method))
            };

            // Send Response (Only if not a notification/id is present)
            if req.id.is_some() {
                let json = serde_json::to_string(&response)?;
                writeln!(self.writer, "{}", json)?;
                self.writer.flush()?;
            }
        }

        Ok(())
    }
}