internal: Simplify logger

crates/rust-analyzer/src/bin/logger.rs

@@ -2,22 +2,16 @@
 //! filter syntax and `tracing_appender` for non blocking output.
 
 use std::{
-    fmt,
     fs::File,
     io::{self, Stderr},
     sync::Arc,
 };
 
 use rust_analyzer::Result;
-use tracing::{level_filters::LevelFilter, Event, Subscriber};
-use tracing_log::NormalizeEvent;
+use tracing::level_filters::LevelFilter;
 use tracing_subscriber::{
-    fmt::{
-        format::Writer, writer::BoxMakeWriter, FmtContext, FormatEvent, FormatFields,
-        FormattedFields, MakeWriter,
-    },
+    fmt::{writer::BoxMakeWriter, MakeWriter},
     layer::SubscriberExt,
-    registry::LookupSpan,
     util::SubscriberInitExt,
     EnvFilter, Registry,
 };
@@ -52,7 +46,7 @@ impl Logger {
         // merge chalk filter to our main filter (from RA_LOG env).
         //
         // The acceptable syntax of CHALK_DEBUG is `target[span{field=value}]=level`.
-        // As the value should only affect chalk crates, we'd better mannually
+        // As the value should only affect chalk crates, we'd better manually
         // specify the target. And for simplicity, CHALK_DEBUG only accept the value
         // that specify level.
         let chalk_level_dir = std::env::var("CHALK_DEBUG")
@@ -63,93 +57,27 @@ impl Logger {
             })
             .ok();
 
-        let chalk_layer = HierarchicalLayer::default()
-            .with_indent_lines(true)
-            .with_ansi(false)
-            .with_indent_amount(2)
-            .with_writer(io::stderr);
-
         let writer = match self.file {
             Some(file) => BoxMakeWriter::new(Arc::new(file)),
             None => BoxMakeWriter::new(io::stderr),
         };
-        let ra_fmt_layer =
-            tracing_subscriber::fmt::layer().event_format(LoggerFormatter).with_writer(writer);
 
-        match chalk_level_dir {
-            Some(val) => {
-                Registry::default()
-                    .with(
-                        self.filter
-                            .add_directive(format!("chalk_solve={}", val).parse()?)
-                            .add_directive(format!("chalk_ir={}", val).parse()?)
-                            .add_directive(format!("chalk_recursive={}", val).parse()?),
-                    )
-                    .with(ra_fmt_layer)
-                    .with(chalk_layer)
-                    .init();
-            }
-            None => {
-                Registry::default().with(self.filter).with(ra_fmt_layer).init();
-            }
-        };
+        let ra_fmt_layer = HierarchicalLayer::default()
+            .with_indent_lines(true)
+            .with_ansi(false)
+            .with_indent_amount(2)
+            .with_targets(true)
+            .with_writer(writer);
+
+        let mut filter = self.filter;
+        if let Some(val) = chalk_level_dir {
+            filter = filter
+                .add_directive(format!("chalk_solve={}", val).parse()?)
+                .add_directive(format!("chalk_ir={}", val).parse()?)
+                .add_directive(format!("chalk_recursive={}", val).parse()?);
+        }
+        Registry::default().with(filter).with(ra_fmt_layer).init();
 
         Ok(())
     }
 }
-
-#[derive(Debug)]
-struct LoggerFormatter;
-
-impl<S, N> FormatEvent<S, N> for LoggerFormatter
-where
-    S: Subscriber + for<'a> LookupSpan<'a>,
-    N: for<'a> FormatFields<'a> + 'static,
-{
-    fn format_event(
-        &self,
-        ctx: &FmtContext<'_, S, N>,
-        mut writer: Writer,
-        event: &Event<'_>,
-    ) -> fmt::Result {
-        // Write level and target
-        let level = *event.metadata().level();
-
-        // If this event is issued from `log` crate, then the value of target is
-        // always "log". `tracing-log` has hard coded it for some reason, so we
-        // need to extract it using `normalized_metadata` method which is part of
-        // `tracing_log::NormalizeEvent`.
-        let target = match event.normalized_metadata() {
-            // This event is issued from `log` crate
-            Some(log) => log.target(),
-            None => event.metadata().target(),
-        };
-        write!(writer, "[{} {}] ", level, target)?;
-
-        // Write spans and fields of each span
-        ctx.visit_spans(|span| {
-            write!(writer, "{}", span.name())?;
-
-            let ext = span.extensions();
-
-            // `FormattedFields` is a a formatted representation of the span's
-            // fields, which is stored in its extensions by the `fmt` layer's
-            // `new_span` method. The fields will have been formatted
-            // by the same field formatter that's provided to the event
-            // formatter in the `FmtContext`.
-            let fields = &ext.get::<FormattedFields<N>>().expect("will never be `None`");
-
-            if !fields.is_empty() {
-                write!(writer, "{{{}}}", fields)?;
-            }
-            write!(writer, ": ")?;
-
-            Ok(())
-        })?;
-
-        // Write fields on the event
-        ctx.field_format().format_fields(writer.by_ref(), event)?;
-
-        writeln!(writer)
-    }
-}