feat(backend) update (unfinished)

backend/server/src/init/logger.rs

@@ -0,0 +1,107 @@
+use std::path::Path;
+use std::{env, io};
+
+use crate::constants::config::general::{default_value, var_name};
+
+use chrono::Local;
+use dirs::home_dir;
+use tracing::info;
+use tracing_appender::{non_blocking, non_blocking::WorkerGuard, rolling};
+use tracing_subscriber::{
+    filter::LevelFilter, fmt, fmt::format::Writer, fmt::time::FormatTime, fmt::MakeWriter,
+    layer::SubscriberExt, Layer, Registry,
+};
+
+struct LocalTimer;
+
+impl FormatTime for LocalTimer {
+    fn format_time(&self, w: &mut Writer<'_>) -> std::fmt::Result {
+        write!(
+            w,
+            "{}",
+            Local::now().format(crate::constants::time::DEFAULT_TIME_FORMAT)
+        )
+    }
+}
+
+type _LogWriter = dyn for<'writer> MakeWriter<'writer, Writer = dyn io::Write + 'static> + 'static;
+
+pub fn init() -> (WorkerGuard, WorkerGuard) {
+    let log_path = match env::var(var_name::LOG_DIR) {
+        Ok(path) => Path::new(&path).to_path_buf(),
+        Err(_) => {
+            let path = if let Ok(default_log_path) = env::var(var_name::WORK_DIR) {
+                expand_home_path(default_log_path)
+            } else {
+                let fallback_path = expand_home_path(default_value::WORK_DIR.to_string());
+                println!(
+                    "[warn] unset env var `{}` and `{}`, trying to log on fallback path: {}/log",
+                    var_name::LOG_DIR,
+                    var_name::WORK_DIR,
+                    fallback_path
+                );
+                fallback_path
+            };
+            Path::new(&path).join("log")
+        }
+    };
+
+    let (info_log_writer, info_guard) = non_blocking(rolling::never(&log_path, "info.log"));
+    let (err_log_writer, error_guard) = non_blocking(rolling::never(&log_path, "error.log"));
+
+    let info_format = tracing_subscriber::fmt::format()
+        .with_level(true)
+        .with_target(true)
+        .with_source_location(true)
+        .with_ansi(false);
+    let err_format = tracing_subscriber::fmt::format()
+        .with_level(true)
+        .with_target(true)
+        .with_source_location(true)
+        .with_ansi(false);
+    let stdout_format = tracing_subscriber::fmt::format()
+        .with_level(true)
+        .with_target(true)
+        .with_source_location(true)
+        .with_timer(LocalTimer);
+
+    let subscribers = Registry::default()
+        .with(
+            fmt::Layer::default()
+                .with_writer(info_log_writer)
+                .event_format(info_format),
+        )
+        .with(
+            fmt::Layer::default()
+                .with_writer(err_log_writer)
+                .event_format(err_format)
+                .with_filter(LevelFilter::ERROR),
+        )
+        .with(
+            fmt::Layer::default()
+                .with_writer(io::stdout)
+                .with_ansi(true)
+                .event_format(stdout_format),
+        );
+
+    tracing::subscriber::set_global_default(subscribers)
+        .expect("[fatal] failed to setup logging system");
+
+    info!("logging to dir: {}", log_path.to_str().unwrap());
+
+    (info_guard, error_guard)
+}
+
+fn expand_home_path(path: String) -> String {
+    if path.starts_with('~') {
+        let home_path = home_dir()
+            .unwrap_or_else(|| panic!("[fatal] unable to locate home dir when parsing env `{}`, try to use absolute path instead", var_name::WORK_DIR));
+        home_path
+            .join(path.strip_prefix("~/").unwrap())
+            .into_os_string()
+            .into_string()
+            .unwrap()
+    } else {
+        path
+    }
+}