logging with log4rs. Rolling, replaced all eprints with info!

1 files changed, 53 insertions, 0 deletions

diff --git a/src/log.rs b/src/log.rs
new file mode 100644
index 0000000..c878085
--- /dev/null
+++ b/src/log.rs
@@ -0,0 +1,53 @@
+use log::LevelFilter;
+use log4rs::{
+    append::rolling_file::{
+        policy::compound::{
+            roll::fixed_window::FixedWindowRoller, trigger::size::SizeTrigger, CompoundPolicy,
+        },
+        RollingFileAppender,
+    },
+    config::{Appender, Config, Root},
+    encode::pattern::PatternEncoder,
+    filter::threshold::ThresholdFilter,
+    Handle,
+};
+
+use crate::fm_error::FmResult;
+
+static LOG_PATH: &str = "~/.config/fm/fm.log";
+
+pub fn set_logger() -> FmResult<Handle> {
+    let window_size = 3; // log0, log1, log2
+    let fixed_window_roller = FixedWindowRoller::builder()
+        .build("log{}", window_size)
+        .unwrap();
+    let size_limit = 5 * 1024; // 5KB as max log file size to roll
+    let size_trigger = SizeTrigger::new(size_limit);
+    let compound_policy =
+        CompoundPolicy::new(Box::new(size_trigger), Box::new(fixed_window_roller));
+    let log_path = shellexpand::tilde(LOG_PATH).to_string();
+
+    // Log Trace level output to file where trace is the default level
+    // and the programmatically specified level to stderr.
+    let config = Config::builder()
+        .appender(
+            Appender::builder()
+                .filter(Box::new(ThresholdFilter::new(LevelFilter::Debug)))
+                .build(
+                    &log_path,
+                    Box::new(
+                        RollingFileAppender::builder()
+                            .encoder(Box::new(PatternEncoder::new("{d} {l}::{m}{n}")))
+                            .build(&log_path, Box::new(compound_policy))?,
+                    ),
+                ),
+        )
+        .build(Root::builder().appender(&log_path).build(LevelFilter::Info))
+        .unwrap();
+
+    // Use this to change log levels at runtime.
+    // This means you can change the default log level to trace
+    // if you are trying to debug an issue and need more logs on then turn it off
+    // once you are done.
+    Ok(log4rs::init_config(config)?)
+}