server: Replay log

[tattlekey] / server / src / main.rs

diff --git a/server/src/main.rs b/server/src/main.rs
index 96f35b25e9360f2bcd9d38d7917620880bba2fa0..ddf5217c41d67a1db956178de083f2d7f0fac753 100644 (file)
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-use serde::Serialize;
+use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::net::UdpSocket;
 use std::time::{Duration, SystemTime, UNIX_EPOCH};
@@ -22,29 +22,38 @@ use std::time::{Duration, SystemTime, UNIX_EPOCH};
 const MESSAGE_SIZE: usize = 12;
 const LOGFILENAME: &str = "log.csv";
 
-#[derive(Eq, Debug, Hash, PartialEq, Serialize)]
+#[derive(Eq, Debug, Hash, PartialEq)]
 struct MessageKey {
     epoch: u32,
     device: u16,
     seq: u16,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Deserialize, Serialize)]
 struct Message {
-    key: MessageKey,
+    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 {
-            key: MessageKey {
-                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")),
-            },
+            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?")
@@ -85,13 +94,28 @@ impl Range {
 }
 
 fn merge_message(presses: &mut HashMap<MessageKey, Range>, message: Message) {
-    if let Some(r) = presses.get_mut(&message.key) {
+    let key = message.key();
+    if let Some(r) = presses.get_mut(&key) {
         if !r.contains(&message.t) {
             r.extend(&message.t);
         }
     } else {
-        presses.insert(message.key, Range::new(&message.t));
+        presses.insert(key, Range::new(&message.t));
+    }
+}
+
+fn replay_log() -> HashMap<MessageKey, Range> {
+    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<std::fs::File> {
@@ -108,7 +132,7 @@ fn open_log_for_writing() -> csv::Writer<std::fs::File> {
 
 fn main() {
     let socket = UdpSocket::bind("0.0.0.0:29803").expect("couldn't bind to address");
-    let mut presses = HashMap::<MessageKey, Range>::new();
+    let mut presses = replay_log();
     let mut log = open_log_for_writing();
     loop {
         let mut buf = [0; MESSAGE_SIZE];
@@ -121,8 +145,7 @@ fn main() {
                     continue;
                 }
                 let message = Message::try_from(filled_buf).expect("I can't count");
-                log.serialize((&message.key, message.t))
-                    .expect("Couldn't write log");
+                log.serialize(&message).expect("Couldn't write log");
                 log.flush().expect("Couldn't flush log");
                 merge_message(&mut presses, message);
             }