Make client append a empty 'clean' file after download succeed

mithril-client/src/services/snapshot.rs

@@ -1,5 +1,6 @@
 use std::{
     fmt::Write,
+    fs::File,
     path::{Path, PathBuf},
     sync::Arc,
     time::Duration,
@@ -209,14 +210,14 @@ impl SnapshotService for MithrilClientSnapshotService {
 
         let unpack_dir = download_dir.join("db");
         let progress_bar = MultiProgress::with_draw_target(progress_target);
-        progress_bar.println("1/7 - Checking local disk info…")?;
+        progress_bar.println("1/8 - Checking local disk info…")?;
         let unpacker = SnapshotUnpacker;
 
         if let Err(e) = unpacker.check_prerequisites(&unpack_dir, snapshot_entity.artifact.size) {
             self.check_disk_space_error(e)?;
         }
 
-        progress_bar.println("2/7 - Fetching the certificate's information…")?;
+        progress_bar.println("2/8 - Fetching the certificate's information…")?;
         let certificate = self
             .certificate_client
             .get(&snapshot_entity.certificate_id)
@@ -227,11 +228,11 @@ impl SnapshotService for MithrilClientSnapshotService {
                 )
             })?;
 
-        progress_bar.println("3/7 - Verifying the certificate chain…")?;
+        progress_bar.println("3/8 - Verifying the certificate chain…")?;
         let verifier = self.verify_certificate_chain(genesis_verification_key, &certificate);
         self.wait_spinner(&progress_bar, verifier).await?;
 
-        progress_bar.println("4/7 - Downloading the snapshot…")?;
+        progress_bar.println("4/8 - Downloading the snapshot…")?;
         let pb = progress_bar.add(ProgressBar::new(snapshot_entity.artifact.size));
         pb.set_style(ProgressStyle::with_template("{spinner:.green} [{elapsed_precise}] [{wide_bar:.cyan/blue}] {bytes}/{total_bytes} ({eta})")
             .unwrap()
@@ -248,11 +249,11 @@ impl SnapshotService for MithrilClientSnapshotService {
                 )
             })?;
 
-        progress_bar.println("5/7 - Unpacking the snapshot…")?;
+        progress_bar.println("5/8 - Unpacking the snapshot…")?;
         let unpacker = unpacker.unpack_snapshot(&snapshot_path, &unpack_dir);
         self.wait_spinner(&progress_bar, unpacker).await?;
 
-        progress_bar.println("6/7 - Computing the snapshot digest…")?;
+        progress_bar.println("6/8 - Computing the snapshot digest…")?;
         let unpacked_snapshot_digest = self
             .immutable_digester
             .compute_digest(&unpack_dir, &certificate.beacon)
@@ -264,7 +265,7 @@ impl SnapshotService for MithrilClientSnapshotService {
                 )
             })?;
 
-        progress_bar.println("7/7 - Verifying the snapshot signature…")?;
+        progress_bar.println("7/8 - Verifying the snapshot signature…")?;
         let expected_message = {
             let mut protocol_message = certificate.protocol_message.clone();
             protocol_message.set_message_part(
@@ -288,6 +289,15 @@ impl SnapshotService for MithrilClientSnapshotService {
             .into());
         }
 
+        progress_bar.println("8/8 - Append 'clean' file to speedup node bootstrap…")?;
+        if let Err(error) = File::create(unpack_dir.join("clean")) {
+            warn!(
+                "Error while creating of a 'clean' file in the unpacked directory to speed\
+                up cardano node bootstrap: {error}.";
+                "unpacked_directory" => &unpack_dir.display()
+            );
+        };
+
         Ok(unpack_dir)
     }
 }
@@ -556,6 +566,51 @@ mod tests {
         assert_eq!(Some(OsStr::new("db")), filepath.file_name());
     }
 
+    #[tokio::test]
+    async fn test_download_snapshot_ok_add_clean_file_allowing_node_bootstrap_speedup() {
+        let test_path = std::env::temp_dir()
+            .join("test_download_snapshot_ok_add_clean_file_allowing_node_bootstrap_speedup");
+        let _ = std::fs::remove_dir_all(&test_path);
+
+        let (http_client, certificate_verifier, digester) =
+            get_mocks_for_snapshot_service_configured_to_make_download_succeed();
+
+        let mut builder = get_dep_builder(Arc::new(http_client));
+        builder.certificate_verifier = Some(Arc::new(certificate_verifier));
+        builder.immutable_digester = Some(Arc::new(digester));
+        let snapshot_service = builder.get_snapshot_service().await.unwrap();
+
+        let snapshot = FromSnapshotMessageAdapter::adapt(get_snapshot_message());
+        build_dummy_snapshot(
+            "digest-10.tar.gz",
+            "1234567890".repeat(124).as_str(),
+            &test_path,
+        );
+
+        let (_, verifier) = setup_genesis();
+        let genesis_verification_key = verifier.to_verification_key();
+
+        let filepath = snapshot_service
+            .download(
+                &snapshot,
+                &test_path,
+                &key_encode_hex(genesis_verification_key).unwrap(),
+                ProgressDrawTarget::hidden(),
+            )
+            .await
+            .expect("Snapshot download should succeed.");
+
+        let clean_file = filepath.join("clean");
+
+        assert!(
+            clean_file.is_file(),
+            "'clean' file should exist and be a file"
+        );
+
+        let clean_file_metadata = clean_file.metadata().unwrap();
+        assert_eq!(clean_file_metadata.len(), 0, "'clean' file should be empty")
+    }
+
     #[tokio::test]
     async fn test_download_snapshot_invalid_digest() {
         let test_path = std::env::temp_dir().join("test_download_snapshot_invalid_digest");