1  // Copyright (c) 2025 ADnet Contributors
 2  // This file is part of the AlphaOS library.
 3  
 4  // Licensed under the Apache License, Version 2.0 (the "License");
 5  // you may not use this file except in compliance with the License.
 6  // You may obtain a copy of the License at:
 7  
 8  // http://www.apache.org/licenses/LICENSE-2.0
 9  
10  // Unless required by applicable law or agreed to in writing, software
11  // distributed under the License is distributed on an "AS IS" BASIS,
12  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  // See the License for the specific language governing permissions and
14  // limitations under the License.
15  
16  use std::io;
17  use tokio::sync::mpsc;
18  
19  pub enum LogWriter {
20      /// Writes to stdout.
21      Stdout(io::Stdout),
22      /// Writes to a channel.
23      Sender(mpsc::Sender<Vec<u8>>),
24  }
25  
26  impl LogWriter {
27      /// Initialize a new log writer.
28      pub fn new(log_sender: &Option<mpsc::Sender<Vec<u8>>>) -> Self {
29          if let Some(sender) = log_sender { Self::Sender(sender.clone()) } else { Self::Stdout(io::stdout()) }
30      }
31  }
32  
33  impl io::Write for LogWriter {
34      /// Writes the given buffer into the log writer.
35      fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
36          match self {
37              Self::Stdout(stdout) => stdout.write(buf),
38              Self::Sender(sender) => {
39                  let log = buf.to_vec();
40                  let _ = sender.try_send(log);
41                  Ok(buf.len())
42              }
43          }
44      }
45  
46      /// Flushes the log writer (no-op).
47      fn flush(&mut self) -> io::Result<()> {
48          Ok(())
49      }
50  }