From 5e0089aedb61d4883df243d0b772868531b09ea6 Mon Sep 17 00:00:00 2001
From: Trivernis <trivernis@gmail.com>
Date: Fri, 3 Apr 2020 08:46:04 +0200
Subject: [PATCH] Add BenchVec as a better way to store and process benchmark
 durations

---
 .idea/discord.xml |   9 ++++
 src/main.rs       | 120 +++++++++++++++++++++++++++++++++-------------
 2 files changed, 97 insertions(+), 32 deletions(-)
 create mode 100644 .idea/discord.xml

diff --git a/.idea/discord.xml b/.idea/discord.xml
new file mode 100644
index 0000000..59b11d1
--- /dev/null
+++ b/.idea/discord.xml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="DiscordProjectSettings">
+    <option name="show" value="true" />
+  </component>
+  <component name="ProjectNotificationSettings">
+    <option name="askShowProject" value="false" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index eb58caf..896267f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,35 +1,104 @@
 #![feature(test)]
+#![allow(dead_code)]
 
 extern crate test;
 
 use rayon::prelude::*;
-use std::ops::{Add, Div};
+use std::fmt::{self, Display};
 use std::time::{Duration, Instant};
 use termion::{color, style};
 
+#[derive(Debug, Clone)]
+struct BenchVec {
+    pub inner: Vec<Duration>,
+}
+
+/// A struct that stores a vector of Durations for benchmarks
+/// and allows some statistical operations on it
+impl BenchVec {
+    /// Creates a new empty BenchVec
+    pub fn new() -> Self {
+        Self { inner: Vec::new() }
+    }
+
+    /// Creates a BenchVec from an existing vector of Durations
+    pub fn from_vec(vec: &Vec<Duration>) -> Self {
+        Self { inner: vec.clone() }
+    }
+
+    /// Adds an element to the BenchVec
+    pub fn push(&mut self, item: Duration) -> &mut Self {
+        self.inner.push(item);
+
+        self
+    }
+
+    /// Appends a different BenchVec to this one
+    pub fn append(&mut self, other: Self) -> &mut Self {
+        self.inner.append(&mut other.inner.clone());
+
+        self
+    }
+
+    /// Returns the length of stored elements
+    pub fn len(&self) -> usize {
+        self.inner.len()
+    }
+
+    /// Returns the sum of all stored elements
+    pub fn sum(&self) -> Duration {
+        self.inner.par_iter().sum::<Duration>()
+    }
+
+    /// Returns the average of all durations
+    pub fn average(&self) -> Duration {
+        self.sum() / self.inner.len() as u32
+    }
+
+    /// Returns the standard deviation of all durations
+    pub fn standard_deviation(&self) -> f64 {
+        (self.sum().as_nanos() as f64 / (self.len() as f64 - 1f64)).sqrt()
+    }
+}
+
+impl Display for BenchVec {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let avg_duration = self.average();
+        let standard_deviation = self.standard_deviation();
+        write!(
+            f,
+            "Average Duration: {:?} (±{:.2}ns ~ {:.1}%)",
+            avg_duration,
+            standard_deviation,
+            (standard_deviation / avg_duration.as_nanos() as f64) * 100f64
+        )
+    }
+}
 const BENCHMARK_ITERATIONS: usize = 1000;
 
 pub fn main() {
     bench_function("Spawn and Stop thread", || {
         to_test::start_stop_thread();
     });
-    bench_function("MPSC channel", || {
+    bench_function("MPSC channel 1000 u128", || {
         to_test::send_mpsc_channel();
     });
-    bench_function("MPMC channel", || {
+    bench_function("MPMC channel 1000 u128", || {
         to_test::send_mpmc_channel();
     });
     bench_function("Multiply to 100", || {
         to_test::multiply_to(100);
     });
-    bench_function("Largest prime", || {
-        to_test::largest_prime(1000000);
+    bench_function("Largest prime until 10000000", || {
+        to_test::largest_prime(10000000);
     });
-    bench_function("Largest prime parallel", || {
-        to_test::largest_prime_par(1000000);
+    bench_function("Largest prime parallel until 10000000", || {
+        to_test::largest_prime_par(10000000);
     })
 }
 
+/// Benchmarks a closure a specific number of times
+/// and reports the results to the commandline
 fn bench_function<F: Fn()>(name: &str, func: F) {
     println!(
         "\n{}{}{}{}",
@@ -38,39 +107,26 @@ fn bench_function<F: Fn()>(name: &str, func: F) {
         name,
         style::Reset
     );
-    let (avg_duration, durations) = bench_n_times(BENCHMARK_ITERATIONS, func);
-    if durations.len() > 10 {
-        println!("Durations(10):\t {:?}...", &durations[0..10]);
+    let bench_durations = bench_n_times(BENCHMARK_ITERATIONS, func);
+    if bench_durations.len() > 10 {
+        println!("Durations(10):\t {:?}...", &bench_durations.inner[0..10]);
     } else {
-        println!("Durations:\t {:?}", durations);
+        println!("Durations:\t {:?}", bench_durations.inner);
     }
-    let standard_deviation = (durations.par_iter().sum::<Duration>().as_nanos() as f64
-        / (BENCHMARK_ITERATIONS as f64 - 1f64))
-        .sqrt();
-    println!(
-        "Average Duration: {:?} (±{:.2}ns ~ {:.1}%)",
-        avg_duration,
-        standard_deviation,
-        (standard_deviation / avg_duration.as_nanos() as f64) * 100f64
-    );
+    println!("{}", bench_durations);
 }
 
-fn bench_n_times<F: Fn()>(n: usize, func: F) -> (Duration, Vec<Duration>) {
-    let mut durations: Vec<Duration> = Vec::new();
+/// Benchmarks a closure a given number of times and returns the
+/// average duration as well as all measured durations
+fn bench_n_times<F: Fn()>(n: usize, func: F) -> BenchVec {
+    let mut durations = BenchVec::new();
     for _ in 0..n {
         let start = Instant::now();
         func();
         durations.push(start.elapsed());
     }
 
-    (
-        durations
-            .par_iter()
-            .cloned()
-            .reduce_with(|a, b| a.add(b).div(2))
-            .unwrap(),
-        durations,
-    )
+    durations
 }
 
 mod to_test {
@@ -133,7 +189,7 @@ mod to_test {
     }
 
     pub fn send_mpsc_channel() {
-        let (rx, tx) = channel::<usize>();
+        let (rx, tx) = channel::<u128>();
         let handle = thread::spawn(move || for _ in tx {});
         for i in 0..1000 {
             rx.send(i).unwrap();
@@ -143,7 +199,7 @@ mod to_test {
     }
 
     pub fn send_mpmc_channel() {
-        let (rx, tx) = unbounded::<usize>();
+        let (rx, tx) = unbounded::<u128>();
         let handle = thread::spawn(move || for _ in tx {});
         for i in 0..1000 {
             rx.send(i).unwrap();