Going back because compile times trippled

src/main/rust/Cargo.lock

@@ -616,19 +616,20 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
 
 [[package]]
-name = "memmap2"
+name = "memmap"
-version = "0.7.1"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f49388d20533534cd19360ad3d6a7dadc885944aa802ba3995040c5ec11288c6"
+checksum = "6585fd95e7bb50d6cc31e20d4cf9afb4e2ba16c5846fc76793f11218da9c475b"
 dependencies = [
  "libc",
+ "winapi",
 ]
 
 [[package]]
 name = "memmap2"
-version = "0.9.4"
+version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fe751422e4a8caa417e13c3ea66452215d7d63e19e604f4980461212f3ae1322"
+checksum = "f49388d20533534cd19360ad3d6a7dadc885944aa802ba3995040c5ec11288c6"
 dependencies = [
  "libc",
 ]
@@ -698,7 +699,7 @@ dependencies = [
  "fast-float",
  "libc",
  "memchr",
- "memmap2 0.9.4",
+ "memmap",
  "polars",
  "rayon",
  "rustc-hash",
@@ -900,7 +901,7 @@ dependencies = [
  "home",
  "itoa",
  "memchr",
- "memmap2 0.7.1",
+ "memmap2",
  "num-traits",
  "once_cell",
  "percent-encoding",

src/main/rust/Cargo.toml

@@ -9,7 +9,7 @@ edition = "2021"
 bstr = "1.9.1"
 fast-float = "0.2.0"
 memchr = "2.7.4"
-memmap2 = "0.9.4"
+memmap = "0.7.0"
 polars = { version = "0.36.2", features = ["csv", "lazy", "nightly", "streaming"]}
 rayon = "1.10.0"
 rustc-hash = "2.0.0"
@@ -47,7 +47,6 @@ name = "phcs"
 harness = false
 
 [profile.release]
-debug = true
 lto = "fat"
-#strip = "symbols"
+strip = "symbols"
 panic = "abort"

src/main/rust/src/implementations/libraries.rs

@@ -1,11 +1,9 @@
-use std::{fs::File, io::BufReader, thread};
+use std::collections::HashMap;
 use std::io::{BufRead, Seek, SeekFrom};
 use std::sync::mpsc;
 use std::time::Instant;
-
+use std::{fs::File, io::BufReader, thread};
-use memmap2::MmapOptions;
+use memmap::MmapOptions;
-use rustc_hash::{FxBuildHasher, FxHashMap as HashMap};
-
 use crate::models::station_measurements::StationMeasurements;
 use crate::utils::parse;
 use crate::utils::parse::hashstr;
@@ -16,9 +14,8 @@ pub fn run() {
     const FILE_PATH: &str = "../../../measurements.txt";
     let now = Instant::now();
     thread::scope(|s| {
-        let hasher = FxBuildHasher::default();
         let mut stations: HashMap<usize, (String, StationMeasurements)> =
-            HashMap::with_capacity_and_hasher(DEFAULT_HASHMAP_LENGTH, hasher);
+            HashMap::with_capacity(DEFAULT_HASHMAP_LENGTH);
         let (tx, rx) = mpsc::channel();
         let cores = thread::available_parallelism().unwrap().into();
         let file = File::open(FILE_PATH).expect("File measurements.txt not found");
@@ -43,19 +40,26 @@ pub fn run() {
         bounds.push(file_length);
         for i in 0..cores {
             let tx = tx.clone();
-            let currposition = *bounds.get(i).unwrap();
+            let mut currposition = *bounds.get(i).unwrap();
             let end = *bounds.get(i + 1).unwrap();
             s.spawn(move || {
                 let file = File::open(FILE_PATH).expect("File measurements.txt not found");
-                let t_mmap = &unsafe { MmapOptions::new().map(&file).unwrap() }[currposition..end];
+                let mut reader = BufReader::new(&file);
+                reader.seek(SeekFrom::Start(currposition as u64)).unwrap();
                 let mut t_stations: HashMap<usize, (String, StationMeasurements)> =
-                    HashMap::with_capacity_and_hasher(DEFAULT_HASHMAP_LENGTH, hasher);
+                    HashMap::with_capacity(DEFAULT_HASHMAP_LENGTH);
-               for line in t_mmap.lines() {
+                let mut line = Vec::with_capacity(108);
-                   let line = line.expect("Could not read line");
+                loop {
-                    let (station, temp) = line.rsplit_once(|char| char == ';').unwrap();
+                    let line_len = reader
+                        .read_until(b'\n', &mut line)
+                        .expect("could not read bytes");
+                    if line_len == 0 {
+                        break;
+                    }
+                    let (station, temp) = line.rsplit_once(|&byte| byte == b';').unwrap();
                     let hash = hashstr(station);
                     let station = unsafe { String::from_utf8_unchecked(Vec::from(station)) };
-                    let temp = parse::temp(temp.as_bytes());
+                    let temp = parse::temp(temp.split_last().unwrap().1);
                     let measurements_option = t_stations.get_mut(&hash);
                     if let Some((_, measurements)) = measurements_option {
                         measurements.update(temp);
@@ -68,6 +72,11 @@ pub fn run() {
                         };
                         t_stations.insert(hash, (station, measurements));
                     }
+                    currposition += line_len;
+                    if currposition >= end {
+                        break;
+                    }
+                    line.clear();
                 }
                 let _ = tx.send(t_stations);
             });

src/main/rust/src/implementations/multi_threaded.rs

@@ -1,12 +1,11 @@
-use std::{fs::File, io::BufReader, thread};
 use std::collections::HashMap;
 use std::io::{BufRead, Seek, SeekFrom};
 use std::sync::mpsc;
 use std::time::Instant;
-
+use std::{fs::File, io::BufReader, thread};
 use crate::models::station_measurements::StationMeasurements;
 use crate::utils::parse;
-use crate::utils::parse::hashbytes;
+use crate::utils::parse::hashstr;
 
 const DEFAULT_HASHMAP_LENGTH: usize = 10000;
 
@@ -57,7 +56,7 @@ pub fn run() {
                         break;
                     }
                     let (station, temp) = line.rsplit_once(|&byte| byte == b';').unwrap();
-                    let hash = hashbytes(station);
+                    let hash = hashstr(station);
                     let station = unsafe { String::from_utf8_unchecked(Vec::from(station)) };
                     let temp = parse::temp(temp.split_last().unwrap().1);
                     let measurements_option = t_stations.get_mut(&hash);

src/main/rust/src/implementations/reference_impl.rs

@@ -1,5 +1,5 @@
 use bstr::{BStr, ByteSlice};
-use memmap2::MmapOptions;
+use memmap::MmapOptions;
 use rayon::prelude::*;
 use rustc_hash::FxHashMap as HashMap;
 use std::time::Instant;

src/main/rust/src/implementations/single_thread.rs

@@ -2,10 +2,9 @@ use std::collections::HashMap;
 use std::fs::File;
 use std::io::{BufRead, BufReader};
 use std::time::Instant;
-
 use crate::models::station_measurements::StationMeasurements;
 use crate::utils::parse;
-use crate::utils::parse::hashbytes;
+use crate::utils::parse::hashstr;
 
 const DEFAULT_HASHMAP_LENGTH: usize = 10000;
 
@@ -25,7 +24,7 @@ pub fn run() {
             break;
         }
         let (station, temp) = line.rsplit_once(|&byte| byte == b';').unwrap();
-        let hash = hashbytes(station);
+        let hash = hashstr(station);
         let station = unsafe { String::from_utf8_unchecked(Vec::from(station)) };
         let temp = parse::temp(temp.split_last().unwrap().1);
         let measurements_option = stations.get_mut(&hash);

src/main/rust/src/utils/parse.rs

@@ -67,7 +67,7 @@ pub fn temp_simd(bytes: &[u8]) -> isize {
 }
 
 #[inline]
-pub fn hashbytes(bytes: &[u8]) -> usize {
+pub fn hashstr(bytes: &[u8]) -> usize {
     let mut hash = 0;
     let (chunks, remainder) = bytes.as_chunks::<8>();
     for &chunk in chunks {
@@ -84,27 +84,9 @@ pub fn hashbytes(bytes: &[u8]) -> usize {
     hash
 }
 
-#[inline]
-pub fn hashstr(s: &str) -> usize {
-    let mut hash = 0;
-    let (chunks, remainder) = s.as_bytes().as_chunks::<8>();
-    for &chunk in chunks {
-        hash += usize::from_be_bytes(chunk);
-    }
-    let mut r = [0_u8; 8];
-    r[0] = remainder.len() as u8;
-    let mut idx = 1;
-    for &byte in remainder {
-        r[idx] = byte;
-        idx += 1;
-    }
-    hash += usize::from_be_bytes(r);
-    hash
-}
-
 #[cfg(test)]
 mod tests {
-    use crate::utils::parse::{hashbytes, hashstr, temp_new};
+    use crate::utils::parse::{hashstr, temp_new};
 
     #[test]
     fn test_temp_new_max() {
@@ -136,23 +118,12 @@ mod tests {
         assert_eq!(temp_neg_10, -99);
     }
 
-    #[test]
-    fn test_hashbytes() {
-        let hash_1 = hashbytes(b"abcdefghijk");
-        let hash_2 = hashbytes(b"kjihgfedcba");
-        let hash_3 = hashbytes(b"abba");
-        let hash_4 = hashbytes(b"baab");
-
-        assert_ne!(hash_1, hash_2);
-        assert_ne!(hash_3, hash_4);
-    }
-
     #[test]
     fn test_hashstr() {
-        let hash_1 = hashstr("abcdefghijk");
+        let hash_1 = hashstr(b"abcdefghijk");
-        let hash_2 = hashstr("kjihgfedcba");
+        let hash_2 = hashstr(b"kjihgfedcba");
-        let hash_3 = hashstr("abba");
+        let hash_3 = hashstr(b"abba");
-        let hash_4 = hashstr("baab");
+        let hash_4 = hashstr(b"baab");
 
         assert_ne!(hash_1, hash_2);
         assert_ne!(hash_3, hash_4);