From f9311fa35e6c2bed9961fe2ea2a1c3b2fbe91745 Mon Sep 17 00:00:00 2001
From: Bruce Leidl <bruce@subgraph.com>
Date: Tue, 2 Apr 2019 15:12:10 -0400
Subject: [PATCH] improved logging system and macros

---
 libcitadel/src/log.rs | 116 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 libcitadel/src/log.rs

diff --git a/libcitadel/src/log.rs b/libcitadel/src/log.rs
new file mode 100644
index 0000000..ea358ec
--- /dev/null
+++ b/libcitadel/src/log.rs
@@ -0,0 +1,116 @@
+
+use std::sync::Mutex;
+use std::io::{self,Write};
+
+use crate::Result;
+
+lazy_static! {
+    static ref LOGGER: Mutex<Logger> = Mutex::new(Logger::new());
+}
+
+#[macro_export]
+macro_rules! debug {
+    ($e:expr) => { $crate::Logger::log($crate::LogLevel::Debug, String::from($e)) };
+    ($fmt:expr, $($arg:tt)+) => { $crate::Logger::log($crate::LogLevel::Debug, format!($fmt, $($arg)+)) };
+}
+
+#[macro_export]
+macro_rules! verbose {
+    ($e:expr) => { $crate::Logger::log($crate::LogLevel::Verbose, String::from($e)) };
+    ($fmt:expr, $($arg:tt)+) => { $crate::Logger::log($crate::LogLevel::Verbose, format!($fmt, $($arg)+)) };
+}
+
+#[macro_export]
+macro_rules! info {
+    ($e:expr) => { $crate::Logger::log($crate::LogLevel::Info, String::from($e)) };
+    ($fmt:expr, $($arg:tt)+) => { $crate::Logger::log($crate::LogLevel::Info, format!($fmt, $($arg)+)) };
+}
+
+#[macro_export]
+macro_rules! notify {
+    ($e:expr) => { $crate::Logger::log($crate::LogLevel::Notice, String::from($e)) };
+    ($fmt:expr, $($arg:tt)+) => { $crate::Logger::log($crate::LogLevel::Notice, format!($fmt, $($arg)+)) };
+}
+
+#[macro_export]
+macro_rules! warn {
+    ($e:expr) => { $crate::Logger::log($crate::LogLevel::Warn, String::from($e)) };
+    ($fmt:expr, $($arg:tt)+) => { $crate::Logger::log($crate::LogLevel::Warn, format!($fmt, $($arg)+)) };
+}
+
+#[derive(PartialOrd,PartialEq,Copy,Clone)]
+pub enum LogLevel {
+    Warn,
+    Notice,
+    Info,
+    Verbose,
+    Debug,
+}
+
+pub trait LogOutput: Send {
+    fn log_output(&mut self, level: LogLevel, line: &str) -> Result<()>;
+}
+
+pub struct Logger {
+    level: LogLevel,
+    output: Box<LogOutput>,
+}
+
+impl Logger {
+    pub fn set_log_level(level: LogLevel) {
+        let mut logger = LOGGER.lock().unwrap();
+        logger.level = level;
+    }
+
+    pub fn set_log_output(output: Box<LogOutput>) {
+        let mut logger = LOGGER.lock().unwrap();
+        logger.output = output;
+    }
+
+    pub fn log(level: LogLevel, message: impl AsRef<str>) {
+        let mut logger = LOGGER.lock().unwrap();
+        logger.log_message(level, message.as_ref());
+    }
+
+    fn new() -> Logger {
+        Logger { level: LogLevel::Notice, output: Box::new(DefaultLogOutput) }
+    }
+
+    fn log_message(&mut self, level: LogLevel, message: &str) {
+        if self.level >= level {
+            if let Err(err) = self.output.log_output(level, message) {
+                eprintln!("Error writing logline: {}", err);
+            }
+        }
+    }
+
+    pub fn format_logline(level: LogLevel, line: &str) -> String {
+        let prefix = match level {
+            LogLevel::Debug   => "[.]",
+            LogLevel::Verbose => "[-]",
+            LogLevel::Info    => "[+]",
+            LogLevel::Notice  => "[*]",
+            LogLevel::Warn    => "[Warning]",
+        };
+        format!("{} {}\n", prefix, line)
+    }
+}
+
+#[derive(Clone)]
+pub struct DefaultLogOutput;
+
+impl DefaultLogOutput {
+    pub fn new() -> Self { DefaultLogOutput }
+}
+
+impl LogOutput for DefaultLogOutput {
+    fn log_output(&mut self, level: LogLevel, line: &str) -> Result<()> {
+        let line = Logger::format_logline(level, line);
+
+        let stdout = io::stdout();
+        let mut lock = stdout.lock();
+        lock.write_all(line.as_bytes())?;
+        lock.flush()?;
+        Ok(())
+    }
+}