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@poonai
Created May 24, 2022
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prime number profiling
use std::fs::File;
use std::io::Write;
use pprof::protos::Message;
#[inline(never)]
fn is_prime_number1(v: usize, prime_numbers: &[usize]) -> bool {
if v < 10000 {
let r = prime_numbers.binary_search(&v);
return r.is_ok();
}
for n in prime_numbers {
if v % n == 0 {
return false;
}
}
true
}
#[inline(never)]
fn is_prime_number2(v: usize, prime_numbers: &[usize]) -> bool {
if v < 10000 {
let r = prime_numbers.binary_search(&v);
return r.is_ok();
}
for n in prime_numbers {
if v % n == 0 {
return false;
}
}
true
}
#[inline(never)]
fn prepare_prime_numbers() -> Vec<usize> {
// bootstrap: Generate a prime table of 0..10000
let mut prime_number_table: [bool; 10000] = [true; 10000];
prime_number_table[0] = false;
prime_number_table[1] = false;
for i in 2..10000 {
if prime_number_table[i] {
let mut v = i * 2;
while v < 10000 {
prime_number_table[v] = false;
v += i;
}
}
}
let mut prime_numbers = vec![];
for i in 2..10000 {
if prime_number_table[i] {
prime_numbers.push(i);
}
}
prime_numbers
}
fn main() {
let prime_numbers = prepare_prime_numbers();
let guard = pprof::ProfilerGuardBuilder::default()
.frequency(100)
.build()
.unwrap();
let mut v = 0;
for i in 0..50000 {
if i % 3 == 0 {
if is_prime_number1(i, &prime_numbers) {
v += 1;
}
}
else {
if is_prime_number2(i, &prime_numbers) {
v += 1;
}
}
}
println!("Prime numbers: {}", v);
if let Ok(report) = guard.report().build() {
let mut file = File::create("profile.pb").unwrap();
let profile = report.pprof().unwrap();
let mut content = Vec::new();
profile.write_to_vec(&mut content).unwrap();
file.write_all(&content).unwrap();
};
}
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