proxmox-backup/src/tools/file_logger.rs
2019-04-06 11:24:37 +02:00

75 lines
1.8 KiB
Rust

use failure::*;
use chrono::{TimeZone, Local};
use std::io::Write;
/// Log messages with timestamps into files
///
/// Logs messages to file, and optionaly to standart output.
///
///
/// #### Example:
/// ```
/// #[macro_use] extern crate proxmox_backup;
/// # use failure::*;
/// use proxmox_backup::tools::FileLogger;
///
/// # std::fs::remove_file("test.log");
/// let mut log = FileLogger::new("test.log", true).unwrap();
/// flog!(log, "A simple log: {}", "Hello!");
/// ```
#[derive(Debug)]
pub struct FileLogger {
file: std::fs::File,
to_stdout: bool,
}
/// Log messages to [FileLogger](tools/struct.FileLogger.html)
#[macro_export]
macro_rules! flog {
($log:expr, $($arg:tt)*) => ({
$log.log(format!($($arg)*));
})
}
impl FileLogger {
pub fn new<P: AsRef<std::path::Path>>(file_name: P, to_stdout: bool) -> Result<Self, Error> {
let file = std::fs::OpenOptions::new()
.read(true)
.write(true)
.create_new(true)
.open(file_name)?;
Ok(Self { file , to_stdout })
}
pub fn log<S: AsRef<str>>(&mut self, msg: S) {
let msg = msg.as_ref();
let mut stdout = std::io::stdout();
if self.to_stdout {
stdout.write(msg.as_bytes()).unwrap();
stdout.write(b"\n").unwrap();
}
let line = format!("{}: {}\n", Local.timestamp(Local::now().timestamp(), 0).to_rfc3339(), msg);
self.file.write(line.as_bytes()).unwrap();
}
}
impl std::io::Write for FileLogger {
fn write(&mut self, buf: &[u8]) -> Result<usize, std::io::Error> {
if self.to_stdout { let _ = std::io::stdout().write(buf); }
self.file.write(buf)
}
fn flush(&mut self) -> Result<(), std::io::Error> {
if self.to_stdout { let _ = std::io::stdout().flush(); }
self.file.flush()
}
}