pounder_test/src/server.rs

228 lines
6.5 KiB
Rust

use heapless::{consts::*, String, Vec};
use core::fmt::Write;
use serde::{Deserialize, Serialize};
use serde_json_core::{de::from_slice, ser::to_string};
use super::iir;
use super::net;
#[derive(Deserialize, Serialize, Debug)]
pub enum AccessRequest {
Read,
Write,
}
#[derive(Deserialize, Serialize, Debug)]
pub struct Request<'a> {
pub req: AccessRequest,
pub attribute: &'a str,
pub value: String<U256>,
}
#[derive(Serialize, Deserialize)]
pub struct IirRequest {
pub channel: u8,
pub iir: iir::IIR,
}
#[derive(Serialize)]
pub struct Response {
code: i32,
attribute: String<U256>,
value: String<U256>,
}
impl<'a> Request<'a> {
pub fn restore_value(&mut self) {
let mut new_value: String<U256> = String::new();
for byte in self.value.as_str().chars() {
if byte == '\'' {
new_value.push('"').unwrap();
} else {
new_value.push(byte).unwrap();
}
}
self.value = new_value;
}
}
impl Response {
/// Remove all double quotation marks from the `value` field of a response.
fn sanitize_value(&mut self) {
let mut new_value: String<U256> = String::new();
for byte in self.value.as_str().chars() {
if byte == '"' {
new_value.push('\'').unwrap();
} else {
new_value.push(byte).unwrap();
}
}
self.value = new_value;
}
/// Remove all double quotation marks from the `value` field of a response and wrap it in single
/// quotes.
fn wrap_and_sanitize_value(&mut self) {
let mut new_value: String<U256> = String::new();
new_value.push('\'').unwrap();
for byte in self.value.as_str().chars() {
if byte == '"' {
new_value.push('\'').unwrap();
} else {
new_value.push(byte).unwrap();
}
}
new_value.push('\'').unwrap();
self.value = new_value;
}
/// Construct a successful reply.
///
/// Note: `value` will be sanitized to convert all single quotes to double quotes.
///
/// Args:
/// * `attrbute` - The attribute of the success.
/// * `value` - The value of the attribute.
pub fn success(attribute: &str, value: &str) -> Self {
let mut res = Self {
code: 200,
attribute: String::from(attribute),
value: String::from(value),
};
res.sanitize_value();
res
}
/// Construct an error reply.
///
/// Note: `message` will be sanitized to convert all single quotes to double quotes.
///
/// Args:
/// * `attrbute` - The attribute of the success.
/// * `message` - The message denoting the error.
pub fn error(attribute: &str, message: &str) -> Self {
let mut res = Self {
code: 400,
attribute: String::from(attribute),
value: String::from(message),
};
res.wrap_and_sanitize_value();
res
}
/// Construct a custom reply.
///
/// Note: `message` will be sanitized to convert all single quotes to double quotes.
///
/// Args:
/// * `attrbute` - The attribute of the success.
/// * `message` - The message denoting the status.
pub fn custom(code: i32, message: &str) -> Self {
let mut res = Self {
code,
attribute: String::from(""),
value: String::from(message),
};
res.wrap_and_sanitize_value();
res
}
}
#[derive(Serialize)]
pub struct Status {
pub t: u32,
pub x0: f32,
pub y0: f32,
pub x1: f32,
pub y1: f32,
}
pub fn json_reply<T: Serialize>(socket: &mut net::socket::TcpSocket, msg: &T) {
let mut u: String<U512> = to_string(msg).unwrap();
u.push('\n').unwrap();
socket.write_str(&u).unwrap();
}
pub struct Server {
data: Vec<u8, U256>,
discard: bool,
}
impl Server {
/// Construct a new server object for managing requests.
pub fn new() -> Self {
Self {
data: Vec::new(),
discard: false,
}
}
/// Poll the server for potential data updates.
///
/// Args:
/// * `socket` - The socket to check contents from.
/// * `f` - A closure that can be called if a request has been received on the server.
pub fn poll<F>(&mut self, socket: &mut net::socket::TcpSocket, mut f: F)
where
F: FnMut(&Request) -> Response,
{
while socket.can_recv() {
let found = socket
.recv(|buf| {
let (len, found) =
match buf.iter().position(|&c| c as char == '\n') {
Some(end) => (end + 1, true),
None => (buf.len(), false),
};
if self.data.len() + len >= self.data.capacity() {
self.discard = true;
self.data.clear();
} else if !self.discard && len > 0 {
self.data.extend_from_slice(&buf[..len]).unwrap();
}
(len, found)
})
.unwrap();
if found {
if self.discard {
self.discard = false;
json_reply(
socket,
&Response::custom(520, "command buffer overflow"),
);
} else {
let r = from_slice::<Request>(
&self.data[..self.data.len() - 1],
);
match r {
Ok(mut res) => {
// Note that serde_json_core doesn't escape quotations within a string.
// To account for this, we manually translate all single quotes to
// double quotes. This occurs because we doubly-serialize this field in
// some cases.
res.restore_value();
let response = f(&res);
json_reply(socket, &response);
}
Err(err) => {
warn!("parse error {:?}", err);
json_reply(
socket,
&Response::custom(550, "parse error"),
);
}
}
}
self.data.clear();
}
}
}
}