Add -E and --show-elapsed flag to show the elapsed time.

src/benchmark/executor.rs

@@ -180,6 +180,7 @@ impl<'a> Executor for ShellExecutor<'a> {
                 COUNT,
                 "Measuring shell spawning time",
                 self.options.output_style,
+                self.options.show_elapsed,
             ))
         } else {
             None
@@ -214,7 +215,8 @@ impl<'a> Executor for ShellExecutor<'a> {
             }
 
             if let Some(bar) = progress_bar.as_ref() {
-                bar.inc(1)
+                bar.inc(1);
+                bar.reset_elapsed();
             }
         }
 

src/benchmark/mod.rs

@@ -155,6 +155,7 @@ impl<'a> Benchmark<'a> {
                     self.options.warmup_count,
                     "Performing warmup runs",
                     self.options.output_style,
+                    self.options.show_elapsed,
                 ))
             } else {
                 None
@@ -164,7 +165,8 @@ impl<'a> Benchmark<'a> {
                 let _ = run_preparation_command()?;
                 let _ = self.executor.run_command_and_measure(self.command, None)?;
                 if let Some(bar) = progress_bar.as_ref() {
-                    bar.inc(1)
+                    bar.inc(1);
+                    bar.reset_elapsed();
                 }
             }
             if let Some(bar) = progress_bar.as_ref() {
@@ -178,6 +180,7 @@ impl<'a> Benchmark<'a> {
                 self.options.run_bounds.min,
                 "Initial time measurement",
                 self.options.output_style,
+                self.options.show_elapsed,
             ))
         } else {
             None
@@ -222,7 +225,8 @@ impl<'a> Benchmark<'a> {
             bar.set_length(count)
         }
         if let Some(bar) = progress_bar.as_ref() {
-            bar.inc(1)
+            bar.inc(1);
+            bar.reset_elapsed();
         }
 
         // Gather statistics (perform the actual benchmark)
@@ -249,7 +253,8 @@ impl<'a> Benchmark<'a> {
             all_succeeded = all_succeeded && success;
 
             if let Some(bar) = progress_bar.as_ref() {
-                bar.inc(1)
+                bar.inc(1);
+                bar.reset_elapsed();
             }
         }
 

src/cli.rs

@@ -221,6 +221,17 @@ fn build_command() -> Command {
                    * 'mean-time': order benchmarks by mean runtime\n"
             ),
         )
+        .arg(
+            Arg::new("show-elapsed")
+                .long("show-elapsed")
+                .short('E')
+                .action(ArgAction::SetTrue)
+                .help(
+                    "Show time elapsed since the current run was started. \
+                     This is useful for especially long benchmarks to see \
+                     the progress the benchmark has made"
+                )
+        )
         .arg(
             Arg::new("time-unit")
                 .long("time-unit")

src/options.rs

@@ -233,6 +233,9 @@ pub struct Options {
 
     /// Which time unit to use when displaying results
     pub time_unit: Option<Unit>,
+
+    /// Show elapsed time since current run start.
+    pub show_elapsed: bool,
 }
 
 impl Default for Options {
@@ -252,6 +255,7 @@ impl Default for Options {
             command_output_policy: CommandOutputPolicy::Null,
             time_unit: None,
             command_input_policy: CommandInputPolicy::Null,
+            show_elapsed: false,
         }
     }
 }
@@ -419,6 +423,10 @@ impl Options {
             CommandInputPolicy::Null
         };
 
+        if matches.get_flag("show-elapsed") {
+            options.show_elapsed = true;
+        }
+
         Ok(options)
     }
 

src/output/progress_bar.rs

@@ -10,12 +10,22 @@ const TICK_SETTINGS: (&str, u64) = ("⠋⠙⠹⠸⠼⠴⠦⠧⠇⠏ ", 80);
 const TICK_SETTINGS: (&str, u64) = (r"+-x| ", 200);
 
 /// Return a pre-configured progress bar
-pub fn get_progress_bar(length: u64, msg: &str, option: OutputStyleOption) -> ProgressBar {
+pub fn get_progress_bar(
+    length: u64,
+    msg: &str,
+    option: OutputStyleOption,
+    show_elapsed: bool,
+) -> ProgressBar {
+    let template_str = match show_elapsed {
+        true => " {spinner} {msg:<30} {wide_bar} ET {elapsed_precise} ETA {eta_precise} ",
+        false => " {spinner} {msg:<30} {wide_bar} ETA {eta_precise} ",
+    };
+
     let progressbar_style = match option {
         OutputStyleOption::Basic | OutputStyleOption::Color => ProgressStyle::default_bar(),
         _ => ProgressStyle::default_spinner()
             .tick_chars(TICK_SETTINGS.0)
-            .template(" {spinner} {msg:<30} {wide_bar} ETA {eta_precise} ")
+            .template(template_str)
             .expect("no template error"),
     };