Truncate server log files only once in one session.

Author: Junfeng Li

src/languageclient.rs

@@ -848,8 +848,7 @@ impl ILanguageClient for Arc<Mutex<State>> {
 
         let stderr = std::fs::OpenOptions::new()
             .create(true)
-            .write(true)
-            .truncate(true)
+            .append(true)
             .open(&get_logpath_server())?;
 
         let process = std::process::Command::new(command.get(0).ok_or_else(|| err_msg("Empty command!"))?)

src/logger.rs

@@ -16,12 +16,19 @@ fn config(level: LogLevelFilter) -> Result<Config> {
 
 pub fn init() -> Result<Handle> {
     {
+        // Truncate log files.
         let mut f = std::fs::OpenOptions::new()
             .create(true)
             .write(true)
             .truncate(true)
             .open(utils::get_logpath())?;
         writeln!(f, "")?;
+        let mut f = std::fs::OpenOptions::new()
+            .create(true)
+            .write(true)
+            .truncate(true)
+            .open(utils::get_logpath_server())?;
+        writeln!(f, "")?;
     }
 
     let handle = log4rs::init_config(config(LogLevelFilter::Warn)?)?;