add working multi log file example

ffplayout/examples/flexi3.rs

@@ -0,0 +1,83 @@
+use flexi_logger::writers::{FileLogWriter, LogWriter};
+use flexi_logger::{Age, Cleanup, Criterion, DeferredNow, FileSpec, Naming, Record};
+use log::{debug, error, info, kv::Value, trace, warn};
+use std::collections::HashMap;
+use std::io;
+use std::sync::{Arc, Mutex};
+
+struct MultiFileLogger {
+    writers: Arc<Mutex<HashMap<String, Arc<Mutex<FileLogWriter>>>>>,
+}
+
+impl MultiFileLogger {
+    pub fn new() -> Self {
+        MultiFileLogger {
+            writers: Arc::new(Mutex::new(HashMap::new())),
+        }
+    }
+
+    fn get_writer(&self, channel: &str) -> io::Result<Arc<Mutex<FileLogWriter>>> {
+        let mut writers = self.writers.lock().unwrap();
+        if !writers.contains_key(channel) {
+            let writer = FileLogWriter::builder(
+                FileSpec::default()
+                    .suppress_timestamp()
+                    .basename("ffplayout")
+                    .discriminant(channel),
+            )
+            .append()
+            .rotate(
+                Criterion::Age(Age::Day),
+                Naming::Timestamps,
+                Cleanup::KeepLogFiles(7),
+            )
+            .print_message()
+            .try_build()
+            .map_err(|e| io::Error::new(io::ErrorKind::Other, e.to_string()))?;
+            writers.insert(channel.to_string(), Arc::new(Mutex::new(writer)));
+        }
+        Ok(writers.get(channel).unwrap().clone())
+    }
+}
+
+impl LogWriter for MultiFileLogger {
+    fn write(&self, now: &mut DeferredNow, record: &Record) -> io::Result<()> {
+        let channel = record
+            .key_values()
+            .get("channel".into())
+            .unwrap_or(Value::null())
+            .to_string();
+        let writer = self.get_writer(&channel);
+        let w = writer?.lock().unwrap().write(now, record);
+
+        w
+    }
+
+    fn flush(&self) -> io::Result<()> {
+        let writers = self.writers.lock().unwrap();
+        for writer in writers.values() {
+            writer.lock().unwrap().flush()?;
+        }
+        Ok(())
+    }
+}
+
+fn main() {
+    let logger = MultiFileLogger::new();
+
+    flexi_logger::Logger::try_with_str("trace")
+        .expect("LogSpecification String has errors")
+        .print_message()
+        .add_writer("file", Box::new(logger))
+        .log_to_stderr()
+        .start()
+        .unwrap();
+
+    trace!(target: "{file}", channel = 1; "This is a trace message for file1");
+    trace!("This is a trace message for console");
+    debug!(target: "{file}", channel = 2; "This is a debug message for file2");
+    info!(target:"{file}", channel = 2; "This is an info message for file2");
+    warn!(target: "{file}", channel = 1; "This is a warning for file1");
+    error!(target: "{file}", channel = 2; "This is an error message for file2");
+    info!("This is a info message for console");
+}