From 1158c74c9dd36f96f49ef4a7e27b27cac0096b1a Mon Sep 17 00:00:00 2001
From: Lars Wirzenius <liw@liw.fi>
Date: Tue, 6 Apr 2021 11:35:48 +0300
Subject: try rayon and fail

---
 src/main.rs | 34 ++++++++++++++++++++++------------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index c67d111..22870a9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,4 @@
+use rayon::prelude::*;
 use sha2::{Digest, Sha256};
 
 const N: usize = 10;
@@ -5,43 +6,52 @@ const SIZE: usize = 128 * 1024;
 
 fn main() {
     println!("sequential");
-    for checksum in Blobs::new(SIZE, N).map(|x| sha256(&x)) {
+    for checksum in Blobs::new(N).map(|x| sha256(&x)) {
         println!("{}", checksum);
     }
 
-    // println!("rayon");
-    // for checksum in blobs.take(N).par_iter().map(|x| sha256(x)) {
-    //     println!("{}", checksum);
-    // }
+    println!("rayon");
+    for checksum in Blobs::new(N).par_iter().map(|x| sha256(&x)) {
+        println!("{}", checksum);
+    }
 }
 
 struct Blobs {
-    size: usize,
     n: usize,
 }
 
 impl Blobs {
-    fn new(size: usize, n: usize) -> Self {
-        Self { size, n }
+    fn new(n: usize) -> Self {
+        Self { n }
+    }
+}
+
+struct Blob {
+    data: [u8; SIZE],
+}
+
+impl Blob {
+    fn new() -> Self {
+        Self { data: [0; SIZE] }
     }
 }
 
 impl Iterator for Blobs {
-    type Item = Vec<u8>;
+    type Item = Blob;
 
     fn next(&mut self) -> Option<Self::Item> {
         if self.n > 0 {
             self.n -= 1;
-            Some(vec![0; self.size])
+            Some(Blob::new())
         } else {
             None
         }
     }
 }
 
-fn sha256(data: &[u8]) -> String {
+fn sha256(blob: &Blob) -> String {
     let mut hasher = Sha256::new();
-    hasher.update(data);
+    hasher.update(&blob.data);
     let hash = hasher.finalize();
     format!("{:x}", hash)
 }
-- 
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