Move crates to subdirectory

crates/backend/src/logger.rs

@@ -0,0 +1,63 @@
+use log::{Level, LevelFilter, Log, Metadata, Record};
+use std::{fmt::Display, sync::Mutex};
+
+/// Register the custom logger. This will panic if called more than once.
+pub fn register() {
+    log::set_boxed_logger(Box::new(Logger::default()))
+        .map(|()| log::set_max_level(LevelFilter::Info))
+        .unwrap();
+}
+
+/// A simple logging handler that prints out all messages and caches them for
+/// later access by the user interface.
+struct Logger {
+    /// All messages since the start of the program.
+    messages: Mutex<Vec<LogMessage>>,
+}
+
+impl Default for Logger {
+    fn default() -> Self {
+        Self {
+            messages: Mutex::new(Vec::new()),
+        }
+    }
+}
+
+impl Log for Logger {
+    fn enabled(&self, metadata: &Metadata) -> bool {
+        metadata.level() <= Level::Info
+    }
+
+    fn log(&self, record: &Record) {
+        if record.level() <= Level::Info {
+            let message = record.into();
+            println!("{}", message);
+            self.messages.lock().unwrap().push(message);
+        }
+    }
+
+    fn flush(&self) {}
+}
+
+/// A simplified representation of a [`Record`].
+struct LogMessage {
+    pub level: String,
+    pub module: String,
+    pub message: String,
+}
+
+impl<'a> From<&Record<'a>> for LogMessage {
+    fn from(record: &Record<'a>) -> Self {
+        Self {
+            level: record.level().to_string(),
+            module: String::from(record.module_path().unwrap_or_else(|| record.target())),
+            message: format!("{}", record.args()),
+        }
+    }
+}
+
+impl Display for LogMessage {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{} ({}): {}", self.module, self.level, self.message)
+    }
+}