feat: create digest engine with Sha256/Md5/None and integrate with save mode

src/modes/save.rs

@@ -11,6 +11,7 @@ use log::debug;
 use rusqlite::Connection;
 
 use crate::db::{self};
+use crate::digest_engine::{DigestEngine, get_engine, DigestType};
 use crate::modes::common::get_meta_from_env;
 use chrono::Utc;
 
@@ -53,6 +54,10 @@ pub fn mode_save(
     let compression_type = compression_type_opt.unwrap();
     debug!("MAIN: Compression type: {}", compression_type);
 
+    // Create a new digest engine
+    let digest_type = DigestType::Sha256;
+    let mut digest_engine = get_engine(digest_type);
+    
     let mut item = db::Item {
         id: None,
         ts: Utc::now(),
@@ -140,6 +145,7 @@ pub fn mode_save(
 
         stdout.write_all(&buffer[..n])?;
         item_out.write_all(&buffer[..n])?;
+        digest_engine.update(&buffer[..n])?;
         item.size = match item.size {
             None => Some(n as i64),
             Some(prev_n) => Some(prev_n + n as i64),
@@ -149,6 +155,10 @@ pub fn mode_save(
 
     stdout.flush()?;
     item_out.flush()?;
+    
+    // Finalize the digest and log the result
+    let digest = digest_engine.finalize()?;
+    debug!("DIGEST: {}", digest);
 
     db::update_item(&conn, item.clone())?;