Performance improvements

+ Optimizing for speed
+ clippy + fmt

.cargo/config

@@ -0,0 +1,3 @@
+[target.x86_64-unknown-linux-gnu]
+linker = "/usr/bin/clang"
+rustflags = ["-Clink-arg=-fuse-ld=lld", "-Clink-arg=-Wl,--no-rosegment"]

Cargo.toml

@@ -8,5 +8,8 @@ edition = "2021"
 [profile.dev]
 overflow-checks = false
 
+[profile.release]
+debug = true
+
 [dependencies]
 

src/lib.rs

@@ -2,6 +2,10 @@
 
 const SHA1_CONST: &[u32] = &[0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0];
 
+fn u32_rotate_left(val: u32, places: u32) -> u32 {
+    val << places | (val >> (32 - places))
+}
+
 pub struct SHA1Hash {
     len: usize,
     data_len: usize,
@@ -33,11 +37,14 @@ impl SHA1Hash {
         let mut buffer = [0u32; 80];
 
         let mut buffer_ndx = 0;
-        for chunk_ndx in (0..self.chunk.len()).step_by(4) {
-            let mut word = [0u8; 4];
+
+        let mut chunk_ndx = 0;
+        let mut word = [0u8; 4];
+        while chunk_ndx < self.chunk.len() {
             word.copy_from_slice(&self.chunk[chunk_ndx..chunk_ndx + 4]);
             buffer[buffer_ndx] = u32::from_be_bytes(word);
             buffer_ndx += 1;
+            chunk_ndx += 4;
         }
 
         for ndx in buffer_ndx..80 {
@@ -54,7 +61,10 @@ impl SHA1Hash {
         let mut f;
         let mut k;
 
-        for (i, word) in buffer.iter().enumerate() {
+        let mut i = 0;
+        while i < buffer.len() {
+            let word = buffer[i];
+
             match i {
                 0..=19 => {
                     f = d ^ (b & (c ^ d));
@@ -75,12 +85,14 @@ impl SHA1Hash {
                 _ => unreachable!("Loop range is 0 to 79"),
             }
 
-            let temp = a.rotate_left(5) + f + e + k + word;
+            let temp = u32_rotate_left(a, 5) + f + e + k + word;
             e = d;
             d = c;
-            c = b.rotate_left(30);
+            c = u32_rotate_left(b, 30);
             b = a;
             a = temp;
+
+            i += 1;
         }
 
         self.state[0] += a;
@@ -146,48 +158,60 @@ impl SHA1Hash {
 mod tests {
     use super::*;
 
-    #[test]
-    fn verify_single_block() {
+    fn verify_sha1(buf: &[u8], expected_hash: &[u8; 20]) {
         let mut sha1 = SHA1Hash::new();
 
-        let msg = "The quick brown fox jumps over the lazy dog\n";
-
-        sha1.digest(msg.as_bytes());
+        sha1.digest(buf);
 
         let output = sha1.finalize();
 
+        assert_eq!(&output, expected_hash);
+    }
+
+    #[test]
+    fn verify_single_block() {
+        let msg = "The quick brown fox jumps over the lazy dog\n";
+
         let expected_hash =
             b"\xbe\x41\x77\x68\xb5\xc3\xc5\xc1\xd9\xbc\xb2\xe7\xc1\x19\x19\x6d\xd7\x6b\x55\x70";
-        assert_eq!(&output, expected_hash);
+
+        verify_sha1(msg.as_bytes(), expected_hash)
     }
 
     #[test]
     fn verify_multi_blocks() {
-        let mut sha1 = SHA1Hash::new();
-
         let msg = "OOPSIE WOOPSIE!! Uwu We make a fucky wucky!! A wittle fucko boingo! The code monkeys at our headquarters are working VEWY HAWD to fix this!\n";
-
-        sha1.digest(msg.as_bytes());
-
-        let output = sha1.finalize();
-
         let expected_hash =
             b"\x14\x09\x49\x37\xfb\x7c\x3c\x30\x02\xda\x1a\x8d\x30\x84\x7f\x1d\xc9\x2b\x36\x0b";
-        assert_eq!(&output, expected_hash);
+
+        verify_sha1(msg.as_bytes(), expected_hash)
     }
 
     #[test]
     fn verify_64_bytes() {
-        let mut sha1 = SHA1Hash::new();
-
         let msg = "a".repeat(64);
 
-        sha1.digest(msg.as_bytes());
-
-        let output = sha1.finalize();
-
         let expected_hash =
             b"\x00\x98\xba\x82\x4b\x5c\x16\x42\x7b\xd7\xa1\x12\x2a\x5a\x44\x2a\x25\xec\x64\x4d";
-        assert_eq!(&output, expected_hash);
+
+        verify_sha1(msg.as_bytes(), expected_hash)
+    }
+
+    #[test]
+    fn verify_speed() {
+        let mut sha1 = SHA1Hash::new();
+        let size = 1048576; // 1024 bytes * 1024 * 1024 = 1GB
+        let buf = [0x55u8; 1024];
+
+        for _ in 0..size {
+            sha1.digest(&buf);
+        }
+
+        let output = sha1.finalize();
+
+        assert_eq!(
+            &output,
+            b"\xa4\x14\xa6\x96\x2c\x6f\x87\x47\x7d\xf2\xc0\x10\xae\x36\x27\xe5\xf1\x9f\x0e\xed"
+        )
     }
 }