server: Only write CSV headers when initially creating the log file

[tattlekey] / server / src / main.rs

diff --git a/server/src/main.rs b/server/src/main.rs
index 94a47d854dac42599b5001993f1d8b5385052d38..573edc580a8a99fc1671e37cb9cb90f6df108c88 100644 (file)
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -14,13 +14,15 @@
 // 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 std::collections::HashMap;
 use std::net::UdpSocket;
 use std::time::{Duration, SystemTime};
 
 const MESSAGE_SIZE: usize = 12;
+const LOGFILENAME: &str = "log.csv";
 
-#[derive(Eq, Debug, Hash, PartialEq)]
+#[derive(Eq, Debug, Hash, PartialEq, Serialize)]
 struct MessageKey {
     epoch: u32,
     device: u16,
@@ -30,7 +32,6 @@ struct MessageKey {
 #[derive(Debug)]
 struct Message {
     key: MessageKey,
-    ago: u32,
     t: SystemTime,
 }
 
@@ -43,7 +44,6 @@ impl From<&[u8; MESSAGE_SIZE]> for Message {
                 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")),
             },
-            ago,
             t: SystemTime::now() - Duration::new(ago.into(), 0),
         }
     }
@@ -81,6 +81,15 @@ impl Range {
 }
 
 fn main() {
+    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");
+    let mut log = csv::WriterBuilder::new()
+        .has_headers(!log_file_exists)
+        .from_writer(logfile);
     let mut presses = HashMap::<MessageKey, Range>::new();
     let socket = UdpSocket::bind("0.0.0.0:29803").expect("couldn't bind to address");
     loop {
@@ -94,13 +103,14 @@ 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.flush().expect("Couldn't flush log");
                 if let Some(r) = presses.get_mut(&message.key) {
                     if !r.contains(&message.t) {
                         r.extend(&message.t);
-                        println!("Updated press: {:?}: {r:?}", message.key);
                     }
                 } else {
-                    println!("Got new press: {:?}: {:?}", message.key, message.t);
                     presses.insert(message.key, Range::new(&message.t));
                 }
             }