feat(rome_cli): add tracing metrics collection and printing (rome#2234)

crates/rome_cli/Cargo.toml

@@ -14,3 +14,8 @@ rome_path = { path = "../rome_path", version = "0.0.0" }
 pico-args = "0.4.2"
 rayon = "1.5.1"
 memmap2 = "0.3.0"
+tracing = "0.1.31"
+tracing-subscriber = "0.3.6"
+parking_lot = "0.12.0"
+lazy_static = "1.4.0"
+hdrhistogram = { version = "7.5.0", default-features = false }

crates/rome_cli/src/commands/format.rs

@@ -365,6 +365,7 @@ struct FormatFileParams<'a> {
 /// This function performs the actual formatting: it reads the file from disk
 /// (or map it into memory it), parse and format it; then, it either writes the
 /// result back or compares it with the original content and emit a diagnostic
+#[tracing::instrument(level = "trace", skip_all, fields(path = ?params.path))]
 fn format_file(params: FormatFileParams) -> Result<Vec<Diagnostic>, Diagnostic> {
     if !params.app.can_format(&RomePath::new(params.path)) {
         return Err(Diagnostic::error(
@@ -376,10 +377,8 @@ fn format_file(params: FormatFileParams) -> Result<Vec<Diagnostic>, Diagnostic>
 
     let source_type = SourceType::try_from(params.path).unwrap_or_else(|_| SourceType::js_module());
 
-    let mut file = fs::File::options()
-        .read(true)
-        .write(true)
-        .open(params.path)
+    let mut file = tracing::debug_span!("open")
+        .in_scope(|| fs::File::options().read(true).write(true).open(params.path))
         .with_file_id(params.file_id)?;
 
     let input = FileBuffer::read(&mut file, !params.is_check).with_file_id(params.file_id)?;

crates/rome_cli/src/lib.rs

@@ -2,6 +2,7 @@ use pico_args::Arguments;
 use rome_core::App;
 
 mod commands;
+mod metrics;
 
 /// Global context for an execution of the CLI
 pub struct CliSession {
@@ -22,13 +23,23 @@ impl CliSession {
 
 /// Main function to run Rome CLI
 pub fn run_cli(mut session: CliSession) {
+    let has_metrics = session.args.contains("--show-metrics");
+    if has_metrics {
+        crate::metrics::init_metrics();
+    }
+
     let has_help = session.args.contains("--help");
     let subcommand = session.args.subcommand();
 
     match subcommand.as_ref().map(Option::as_deref) {
         Ok(Some(cmd)) if has_help => crate::commands::help::help(Some(cmd)),
 
-        Ok(Some("format")) => crate::commands::format::format(session),
+        Ok(Some("format")) => {
+            crate::commands::format::format(session);
+            if has_metrics {
+                crate::metrics::print_metrics();
+            }
+        }
 
         Ok(None | Some("help")) => crate::commands::help::help(None),