Logging improvements

src/cli/mod.rs

@@ -14,13 +14,15 @@ mod config;
 mod import;
 mod ui;
 
-use crate::{Cache, Config, USER_AGENT};
+use crate::{Cache, Config, PKG_NAME, PKG_VERSION, USER_AGENT};
 use clap::{Parser, Subcommand};
 use log::LevelFilter;
 use simplelog::{ConfigBuilder as LogConfigBuilder, WriteLogger};
 use std::borrow::Cow;
-use std::fs::OpenOptions;
-use std::path::PathBuf;
+use std::ffi::OsString;
+use std::fs::{self, File};
+use std::io;
+use std::path::{Path, PathBuf};
 use xdg::BaseDirectories;
 
 /// Command line Arguments.
@@ -48,6 +50,44 @@ enum Commands {
     Analyze(analyze::Args),
 }
 
+/// Append a numeric suffix (e.g., `.1`) to a path.
+fn append_numeric_suffix_to_path(base_path: impl AsRef<Path>, number: usize) -> PathBuf {
+    let suffix: OsString = format!(".{number}").into();
+    let new_extension = base_path.as_ref().extension().map_or_else(
+        || OsString::from(&suffix),
+        |ext| {
+            let mut extension = ext.to_os_string();
+            extension.push(&suffix);
+            extension
+        },
+    );
+    base_path.as_ref().with_extension(new_extension)
+}
+
+/// Rotate logfiles by renaming `<log>` to `<log>.0`, `<log>.1` to `<log>.2`, etc.
+fn rotate_logfiles(base_path: impl AsRef<Path>) -> io::Result<()> {
+    let paths_to_rename = (0..7)
+        .rev()
+        .map(|i| {
+            (
+                append_numeric_suffix_to_path(&base_path, i),
+                append_numeric_suffix_to_path(&base_path, i + 1),
+            )
+        })
+        .chain(std::iter::once((
+            base_path.as_ref().to_path_buf(),
+            append_numeric_suffix_to_path(&base_path, 0),
+        )));
+    for (old_path, new_path) in paths_to_rename {
+        fs::rename(old_path, new_path).or_else(|err| match err.kind() {
+            io::ErrorKind::NotFound => Ok(()),
+            _ => Err(err),
+        })?;
+    }
+
+    Ok(())
+}
+
 /// Main entry point.
 ///
 /// # Errors
@@ -61,19 +101,22 @@ enum Commands {
 pub async fn main() -> crate::Result<()> {
     let args = Args::parse();
 
-    let base_dirs = BaseDirectories::with_prefix(env!("CARGO_PKG_NAME"))?;
+    let base_dirs = BaseDirectories::with_prefix(PKG_NAME)?;
 
     // Initialize logging
-    let logfile_path = base_dirs.place_state_file("helicon.log")?;
-    let logfile = OpenOptions::new().append(true).open(logfile_path)?;
+    let logfile_path = base_dirs.place_state_file(format!("{PKG_NAME}.log"))?;
+    rotate_logfiles(&logfile_path)?;
+    let logfile = File::create(logfile_path)?;
     WriteLogger::init(
         LevelFilter::Debug,
         LogConfigBuilder::new()
+            .set_time_format_rfc3339()
             .add_filter_ignore_str("symphonia_core::probe")
             .build(),
         logfile,
     )
     .expect("Failed to initialize logging");
+    log::info!("Started {PKG_NAME} {PKG_VERSION}");
 
     // Load configuration
     let config = base_dirs

src/config.rs

@@ -414,6 +414,7 @@ mod builder {
         /// Add a file to be loaded to the configuration builder. Files added later will override
         /// values from previous files.
         pub fn with_file<P: AsRef<Path>>(mut self, path: P) -> Self {
+            log::debug!("Reading config from file: {}", path.as_ref().display());
             self.0 = self
                 .0
                 .add_source(File::from(path.as_ref()).format(FileFormat::Toml));
@@ -423,6 +424,10 @@ mod builder {
         /// Add a file to be loaded to the configuration builder. Files added later will override
         /// values from previous files.
         pub fn with_str<S: AsRef<str>>(mut self, value: S) -> Self {
+            log::debug!(
+                "Reading config from string ({} bytes)",
+                value.as_ref().len()
+            );
             self.0 = self
                 .0
                 .add_source(File::from_str(value.as_ref(), FileFormat::Toml));
@@ -431,6 +436,7 @@ mod builder {
 
         /// Add the default configuration to the configuration builder.
         pub fn with_defaults(self) -> Self {
+            log::debug!("Reading default config as string");
             self.with_str(DEFAULT_CONFIG)
         }
 
@@ -472,3 +478,22 @@ impl Config {
         Self::load_from_str(DEFAULT_CONFIG)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_load_default() {
+        let config = Config::load_default().unwrap();
+        let serialized = toml::to_string_pretty(&config).unwrap();
+        println!("{serialized}");
+    }
+
+    #[test]
+    fn test_build_with_defaults() {
+        let config = Config::builder().with_defaults().build().unwrap();
+        let serialized = toml::to_string_pretty(&config).unwrap();
+        println!("{serialized}");
+    }
+}

src/lib.rs

@@ -71,5 +71,11 @@ pub use self::error::{ErrorType as Error, Result};
 pub use self::taggedfile::TaggedFile;
 pub use self::taggedfilecollection::TaggedFileCollection;
 
+/// Name of this package.
+const PKG_NAME: &str = env!("CARGO_PKG_NAME");
+
+/// Version of this package.
+const PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
+
 /// The User-Agent header that will be used for HTTP requests (i.e., for MusicBrainz).
 pub const USER_AGENT: &str = concat!(env!("CARGO_PKG_NAME"), "/", env!("CARGO_PKG_VERSION"));