use log crate instead of own debug! macro

This also does away with the scary unsafe{} blocks just to set/get the
DEBUG flag.

1 files changed, 30 insertions, 0 deletions

diff --git a/src/logger.rs b/src/logger.rs
new file mode 100644
index 0000000..f47d19e
--- /dev/null
+++ b/src/logger.rs
@@ -0,0 +1,30 @@
+use log::{Level, LevelFilter, Metadata, Record};
+
+struct StderrLogger(LevelFilter);
+
+impl log::Log for StderrLogger {
+    fn enabled(&self, metadata: &Metadata) -> bool {
+        metadata.level() <= self.0
+    }
+
+    fn log(&self, record: &Record) {
+        if self.enabled(record.metadata()) {
+            eprintln!("{} - {}", record.level(), record.args());
+        }
+    }
+
+    fn flush(&self) {}
+}
+
+/// Initializes the logging with the desired level.
+///
+/// Note that this should only be called once per program start.
+///
+/// The given level is the maximum level that you want to output. Messages higher than that will be
+/// discarded.
+pub fn initialize(max_level: Level) {
+    let filter = max_level.to_level_filter();
+    let logger = Box::new(StderrLogger(filter));
+    log::set_boxed_logger(logger).expect("Failed to set logger");
+    log::set_max_level(filter);
+}