add md5, minor changes to trait

src/args.rs

@@ -25,4 +25,7 @@ pub struct Args {
     /// Blake2b256
     #[arg(long)]
     pub blake256: bool,
+    /// MD5
+    #[arg(long)]
+    pub md5: bool,
 }

src/hashes.rs

@@ -2,6 +2,7 @@ mod null_hash;
 
 use crate::Args;
 
+use md5::digest;
 use std::sync::Arc;
 
 type BITS256 = [u8; 32];
@@ -46,12 +47,8 @@ impl HashReturn {
 
 pub trait Hasher {
     fn new() -> Self;
-    fn digest(&mut self, bytes: ArcU8);
+    fn digest(&mut self, bytes: impl AsRef<[u8]>);
     fn complete(self) -> HashReturn;
 }
 
-struct HashKeeper {}
+pub struct Hashes {}
-
-pub struct Hashes {
-    hashes: Args,
-}

src/hashes/null_hash.rs

@@ -22,7 +22,7 @@ impl Hasher for NullHash {
     fn new() -> Self {
         NullHash { hash: [0; 32] }
     }
-    fn digest(&mut self, bytes: ArcU8) {
+    fn digest(&mut self, bytes: impl AsRef<[u8]>) {
         let bytes = bytes.as_ref();
 
         let start_point = if bytes.len() < 32 {
@@ -50,7 +50,7 @@ mod test {
         let mut hasher = NullHash::new();
 
         for i in 0..32u8 {
-            hasher.digest(Arc::new([i; 1]));
+            hasher.digest([i; 1]);
         }
 
         assert_eq!(*hasher.complete().into_bytes().first().unwrap(), 31);
@@ -66,7 +66,7 @@ mod test {
             *byte = i;
         }
 
-        hasher.digest(Arc::new(source_bytes));
+        hasher.digest(source_bytes);
 
         let result = hasher.complete().into_bytes();