refactor, add rayon

Sponsored-by: author

2 files changed, 30 insertions, 53 deletions

diff --git a/Cargo.toml b/Cargo.toml
index dffbe19..fd7084f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,5 +1,5 @@
 [package]
-name = "checksums_threads"
+name = "checksums"
 version = "0.1.0"
 edition = "2021"
 
@@ -8,4 +8,5 @@ edition = "2021"
 [dependencies]
 anyhow = "1.0.56"
 clap = { version = "3.1.6", features = ["derive"] }
+rayon = "1.5.1"
 sha2 = "0.10.2"
diff --git a/src/main.rs b/src/main.rs
index 2f3fbff..43ad299 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,69 +1,45 @@
 use clap::Parser;
-use sha2::{Digest, Sha256};
-use std::fs::File;
-use std::io::{BufReader, Read};
-use std::path::{Path, PathBuf};
-
-const BUF_SIZE: usize = 4096;
+use rayon::prelude::*;
+use std::path::PathBuf;
+use checksums::*;
 
 fn main() {
     let args = Args::parse();
-    if let Err(e) = checksums_main(&args.filenames) {
+
+    if let Err(e) = checksums_linear(&args.filenames) {
         eprintln!("ERROR: {e}");
         std::process::exit(1);
     }
-}
 
-fn checksums_main(filenames: &[PathBuf]) -> anyhow::Result<()> {
-    let checksums: Result<Vec<FileChecksum>, std::io::Error> = filenames
-        .iter()
-        .map(|filename| checksum(filename))
-        .collect();
-    for c in checksums? {
-        c.print();
+    println!();
+    if let Err(e) = checksums_rayon(&args.filenames) {
+        eprintln!("ERROR: {e}");
+        std::process::exit(1);
     }
-    Ok(())
 }
 
-fn checksum(filename: &Path) -> Result<FileChecksum, std::io::Error> {
-    let mut checksum = Sha256::new();
-
-    let file = File::open(filename)?;
-    let mut reader = BufReader::new(file);
-    loop {
-        let mut buf = vec![0; BUF_SIZE];
-        let n = reader.read(&mut buf)?;
-        if n == 0 {
-            break;
-        }
-        checksum.update(&buf[..n]);
+fn print(checksums: &[FileChecksum]) {
+    for c in checksums {
+        c.print();
     }
-
-    let checksum = checksum.finalize();
-    let checksum = format!("{checksum:x}");
-    Ok(FileChecksum::new(filename, checksum))
 }
 
-#[derive(Parser)]
-struct Args {
-    filenames: Vec<PathBuf>,
-}
-
-#[derive(Debug)]
-struct FileChecksum {
-    filename: PathBuf,
-    checksum: String,
+fn checksums_linear(filenames: &[PathBuf]) -> anyhow::Result<()> {
+    println!("linear");
+    let checksums: Result<Vec<FileChecksum>, std::io::Error> = filenames
+        .iter()
+        .map(|filename| checksum(filename))
+        .collect();
+    print(&checksums?);
+    Ok(())
 }
 
-impl FileChecksum {
-    fn new(filename: &Path, checksum: String) -> Self {
-        Self {
-            filename: filename.to_path_buf(),
-            checksum,
-        }
-    }
-
-    fn print(&self) {
-        println!("{} {}", self.checksum, self.filename.display());
-    }
+fn checksums_rayon(filenames: &[PathBuf]) -> anyhow::Result<()> {
+    println!("rayon");
+    let checksums: Result<Vec<FileChecksum>, std::io::Error> = filenames
+        .par_iter()
+        .map(|filename| checksum(filename))
+        .collect();
+    print(&checksums?);
+    Ok(())
 }