server: Replay log

[tattlekey] / server / src / main.rs

diff --git a/server/src/main.rs b/server/src/main.rs
index 500c2f55f9fba7296c4eb17d68be5a7d75e86e8b..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::ser::{Serialize, SerializeStruct, Serializer};
+use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::net::UdpSocket;
 use std::time::{Duration, SystemTime, UNIX_EPOCH};
@@ -29,23 +29,20 @@ struct MessageKey {
     seq: u16,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Deserialize, Serialize)]
 struct Message {
-    key: MessageKey,
+    epoch: u32,
+    device: u16,
+    seq: u16,
     t: u64,
 }
-impl Serialize for Message {
-    // https://github.com/BurntSushi/rust-csv/issues/155
-    // https://github.com/BurntSushi/rust-csv/issues/98
-    // https://github.com/BurntSushi/rust-csv/pull/223
-    // csv doesn't support #[serde(flatten)], so we implement this directly.  :(
-    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
-        let mut row = serializer.serialize_struct("Message", 4)?;
-        row.serialize_field("epoch", &self.key.epoch)?;
-        row.serialize_field("device", &self.key.device)?;
-        row.serialize_field("seq", &self.key.seq)?;
-        row.serialize_field("t", &self.t)?;
-        row.end()
+impl Message {
+    fn key(&self) -> MessageKey {
+        MessageKey {
+            epoch: self.epoch,
+            device: self.device,
+            seq: self.seq,
+        }
     }
 }
 
@@ -54,11 +51,9 @@ impl From<&[u8; MESSAGE_SIZE]> for Message {
         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?")
@@ -99,13 +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> {
@@ -122,7 +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];