server: Extract merge_message()

[tattlekey] / server / src / main.rs

diff --git a/server/src/main.rs b/server/src/main.rs
index 62ef41ef40a71d5fd436739ef2e15f1b83c2dd01..bf4f4fcd0c5d43257dcbc3e26c14b70e0ce9fc23 100644 (file)
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -80,15 +80,32 @@ impl Range {
     }
 }
 
-fn main() {
+fn merge_message(presses: &mut HashMap<MessageKey, Range>, message: Message) {
+    if let Some(r) = presses.get_mut(&message.key) {
+        if !r.contains(&message.t) {
+            r.extend(&message.t);
+        }
+    } else {
+        presses.insert(message.key, Range::new(&message.t));
+    }
+}
+
+fn open_log_for_writing() -> csv::Writer<std::fs::File> {
+    let log_file_exists = std::path::Path::new(LOGFILENAME).exists();
     let logfile = std::fs::OpenOptions::new()
-        .create(true)
+        .create_new(!log_file_exists)
         .append(true)
         .open(LOGFILENAME)
         .expect("Coudln't open log file");
-    let mut log = csv::Writer::from_writer(logfile);
-    let mut presses = HashMap::<MessageKey, Range>::new();
+    csv::WriterBuilder::new()
+        .has_headers(!log_file_exists)
+        .from_writer(logfile)
+}
+
+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 log = open_log_for_writing();
     loop {
         let mut buf = [0; MESSAGE_SIZE];
         match socket.recv_from(&mut buf) {
@@ -103,13 +120,7 @@ fn main() {
                 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);
-                    }
-                } else {
-                    presses.insert(message.key, Range::new(&message.t));
-                }
+                merge_message(&mut presses, message);
             }
         }
     }