X-Git-Url: http://git.scottworley.com/tattlekey/blobdiff_plain/891f78b762fa77f19899024d6d9977cf6e635467..v0.1.0:/server/src/main.rs diff --git a/server/src/main.rs b/server/src/main.rs index e7a11a9..ddf5217 100644 --- a/server/src/main.rs +++ b/server/src/main.rs @@ -1,3 +1,154 @@ +// tattlekey: A one-key UDP keyboard +// Copyright (C) 2023 Scott Worley +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this program. If not, see . + +use serde::{Deserialize, Serialize}; +use std::collections::HashMap; +use std::net::UdpSocket; +use std::time::{Duration, SystemTime, UNIX_EPOCH}; + +const MESSAGE_SIZE: usize = 12; +const LOGFILENAME: &str = "log.csv"; + +#[derive(Eq, Debug, Hash, PartialEq)] +struct MessageKey { + epoch: u32, + device: u16, + seq: u16, +} + +#[derive(Debug, Deserialize, Serialize)] +struct Message { + epoch: u32, + device: u16, + seq: u16, + t: u64, +} +impl Message { + fn key(&self) -> MessageKey { + MessageKey { + epoch: self.epoch, + device: self.device, + seq: self.seq, + } + } +} + +impl From<&[u8; MESSAGE_SIZE]> for Message { + fn from(value: &[u8; MESSAGE_SIZE]) -> Self { + let ago = u32::from_be_bytes(value[8..=11].try_into().expect("I can't count")); + let press_time = SystemTime::now() - Duration::new(ago.into(), 0); + Self { + epoch: u32::from_be_bytes(value[0..=3].try_into().expect("I can't count")), + device: u16::from_be_bytes(value[4..=5].try_into().expect("I can't count")), + seq: u16::from_be_bytes(value[6..=7].try_into().expect("I can't count")), + t: press_time + .duration_since(UNIX_EPOCH) + .expect("Bad time?") + .as_secs(), + } + } +} +impl TryFrom<&[u8]> for Message { + type Error = std::array::TryFromSliceError; + fn try_from(value: &[u8]) -> Result { + match <[u8; MESSAGE_SIZE]>::try_from(value) { + Ok(correct_size) => Ok(Message::from(&correct_size)), + Err(e) => Err(e), + } + } +} + +#[derive(Debug)] +struct Range { + start: u64, + end: u64, +} +impl Range { + fn new(t: &u64) -> Self { + Self { start: *t, end: *t } + } + fn contains(&self, t: &u64) -> bool { + t > &self.start && t < &self.end + } + fn extend(&mut self, t: &u64) { + if t < &self.start { + self.start = *t; + } + if t > &self.end { + self.end = *t; + } + } +} + +fn merge_message(presses: &mut HashMap, message: Message) { + let key = message.key(); + if let Some(r) = presses.get_mut(&key) { + if !r.contains(&message.t) { + r.extend(&message.t); + } + } else { + presses.insert(key, Range::new(&message.t)); + } +} + +fn replay_log() -> HashMap { + let mut presses = HashMap::new(); + if std::path::Path::new(LOGFILENAME).exists() { + let mut log = csv::Reader::from_path(LOGFILENAME).expect("Couldn't open log for replay"); + for message in log.deserialize() { + merge_message( + &mut presses, + message.expect("Error reading log during replay"), + ); + } + } + presses +} + +fn open_log_for_writing() -> csv::Writer { + let log_file_exists = std::path::Path::new(LOGFILENAME).exists(); + let logfile = std::fs::OpenOptions::new() + .create_new(!log_file_exists) + .append(true) + .open(LOGFILENAME) + .expect("Coudln't open log file"); + csv::WriterBuilder::new() + .has_headers(!log_file_exists) + .from_writer(logfile) +} + fn main() { - println!("Hello, world!"); + let socket = UdpSocket::bind("0.0.0.0:29803").expect("couldn't bind to address"); + let mut presses = replay_log(); + let mut log = open_log_for_writing(); + loop { + let mut buf = [0; MESSAGE_SIZE]; + match socket.recv_from(&mut buf) { + Err(e) => eprintln!("Didn't receive data: {e}"), + Ok((number_of_bytes, src_addr)) => { + let filled_buf = &buf[..number_of_bytes]; + if number_of_bytes != MESSAGE_SIZE { + eprintln!("Ignoring short message ({number_of_bytes}) from {src_addr}"); + continue; + } + let message = Message::try_from(filled_buf).expect("I can't count"); + log.serialize(&message).expect("Couldn't write log"); + log.flush().expect("Couldn't flush log"); + merge_message(&mut presses, message); + } + } + } }