refactor(timings): move Concurrency into report module

It is no longer used outside the module

Author: weihanglo

src/cargo/core/compiler/timings/mod.rs

@@ -103,20 +103,6 @@ struct UnitTime {
     sections: IndexMap<String, CompilationSection>,
 }
 
-/// Periodic concurrency tracking information.
-#[derive(serde::Serialize)]
-struct Concurrency {
-    /// Time as an offset in seconds from `Timings::start`.
-    t: f64,
-    /// Number of units currently running.
-    active: usize,
-    /// Number of units that could run, but are waiting for a jobserver token.
-    waiting: usize,
-    /// Number of units that are not yet ready, because they are waiting for
-    /// dependencies to finish.
-    inactive: usize,
-}
-
 /// Data for a single compilation unit, prepared for serialization to JSON.
 ///
 /// This is used by the HTML report's JavaScript to render the pipeline graph.

src/cargo/core/compiler/timings/report.rs

@@ -11,7 +11,6 @@ use itertools::Itertools as _;
 use crate::CargoResult;
 use crate::core::compiler::Unit;
 
-use super::Concurrency;
 use super::UnitData;
 use super::UnitTime;
 
@@ -82,6 +81,20 @@ impl SectionData {
     }
 }
 
+/// Concurrency tracking information.
+#[derive(serde::Serialize)]
+pub struct Concurrency {
+    /// Time as an offset in seconds from `Timings::start`.
+    t: f64,
+    /// Number of units currently running.
+    active: usize,
+    /// Number of units that could run, but are waiting for a jobserver token.
+    waiting: usize,
+    /// Number of units that are not yet ready, because they are waiting for
+    /// dependencies to finish.
+    inactive: usize,
+}
+
 pub struct RenderContext<'a> {
     /// When Cargo started.
     pub start: Instant,