feat(cross-platform): add QUICKSTART.md, live crash test, and platform abstraction module

tests/live_crash_resilience_test.rs

@@ -0,0 +1,152 @@
+use std::path::PathBuf;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::Arc;
+
+use bytes::Bytes;
+use dav_server::{
+    davpath::DavPath,
+    fs::{DavFileSystem, OpenOptions},
+};
+use rand::RngCore;
+use sanctum::{
+    crypto::{derive_kek, generate_dek, generate_salt, wrap_dek, KdfParams, FORMAT_VERSION},
+    storage::Database,
+    verify::verify_container,
+    vfs::SanctumFs,
+};
+
+/// Live-Crash- und Stresstest: Simuliert harten Verbindungsabbruch und Power-Cut
+/// während intensiver paralleler Schreibvorgänge im VFS.
+#[tokio::test]
+async fn test_live_crash_and_recovery_stress() {
+    let temp_dir = std::env::temp_dir();
+    let container_path: PathBuf = temp_dir.join(format!("sanctum_live_stress_{}.sanctum", std::process::id()));
+    if container_path.exists() {
+        let _ = std::fs::remove_file(&container_path);
+    }
+
+    let password = "LiveStressPassword2026!";
+    let salt = generate_salt();
+    let kdf_params = KdfParams {
+        memory_cost: 1024,
+        time_cost: 1,
+        parallelism: 1,
+    };
+    let kek = derive_kek(password, &salt, &kdf_params).expect("KEK derivation");
+    let dek = generate_dek();
+    let (wrapped_dek, header_nonce, header_tag) = wrap_dek(&kek, &dek).expect("DEK wrapping");
+
+    // 1. Initialisierung des Containers
+    {
+        let db = Database::open(&container_path).expect("Open database");
+        db.init_schema(&salt, &kdf_params, &wrapped_dek, &header_nonce, &header_tag)
+            .expect("Init schema");
+        db.checkpoint().expect("Initial Checkpoint");
+    }
+
+    // 2. Parallele Schreiblast mit SanctumFs erzeugen
+    let stop_signal = Arc::new(AtomicBool::new(false));
+    let db = Database::open(&container_path).expect("Open database for VFS");
+    let fs = SanctumFs::new(db, dek.clone(), FORMAT_VERSION);
+
+    let mut handles = Vec::new();
+
+    // Spawn 4 parallele Schreiber
+    for worker_id in 0..4 {
+        let fs_clone = fs.clone();
+        let stop_clone = stop_signal.clone();
+
+        let handle = tokio::spawn(async move {
+            let mut file_idx = 0;
+            while !stop_clone.load(Ordering::Relaxed) && file_idx < 10 {
+                let file_path_str = format!("/worker_{}_file_{}.dat", worker_id, file_idx);
+                let dav_path = DavPath::new(&file_path_str).unwrap();
+
+                let mut opts = OpenOptions::default();
+                opts.write = true;
+                opts.create = true;
+                opts.truncate = true;
+
+                // Datei anlegen
+                let mut file = match fs_clone.open(&dav_path, opts).await {
+                    Ok(f) => f,
+                    Err(_) => break,
+                };
+
+                // Mehrere 256-KB Blöcke schreiben (über mehrere Chunks hinweg)
+                let mut payload = vec![0u8; 256 * 1024];
+                rand::thread_rng().fill_bytes(&mut payload);
+
+                for _ in 0..6 {
+                    if stop_clone.load(Ordering::Relaxed) {
+                        break;
+                    }
+                    let _ = file.write_bytes(Bytes::copy_from_slice(&payload)).await;
+                }
+                let _ = file.flush().await;
+                file_idx += 1;
+            }
+        });
+        handles.push(handle);
+    }
+
+    // Lass die Worker 500ms unter Volllast schreiben
+    tokio::time::sleep(tokio::time::Duration::from_millis(500)).await;
+
+    // 3. Simuliere abrupten Prozessabbruch (Hard Kill / Power Cut)
+    // Wir brechen die Worker hart ab (Cancel) und verwerfen das FS-Handle ohne sauberen Unmount
+    stop_signal.store(true, Ordering::SeqCst);
+    for h in handles {
+        h.abort(); // Simuliert Kill
+    }
+
+    // FS ohne Checkpoint/Drop-Finalisierung freigeben
+    drop(fs);
+
+    // 4. Recovery & Integritätsprüfung nach Crash
+    // Das System muss die SQLite WAL-Datei automatisch erkennen und verarbeiten
+    let verify_result = verify_container(&container_path, Some(&dek), false).expect("Verify post-crash");
+    assert!(
+        verify_result.is_healthy(),
+        "Container muss nach Crash vollkommen konsistent sein! Fehler: {:?}",
+        verify_result.errors
+    );
+    assert_eq!(verify_result.corrupted_chunks, 0, "Keine korrupten Chunks erlaubt");
+
+    // 5. Konsistentes Weiterarbeiten nach dem Absturz
+    let db_recovered = Database::open(&container_path).expect("Open database after crash");
+    let fs_recovered = SanctumFs::new(db_recovered, dek.clone(), FORMAT_VERSION);
+
+    // Neue Datei im wiederhergestellten Dateisystem anlegen und lesen
+    let recovery_test_path = DavPath::new("/post_crash_verification.txt").unwrap();
+    {
+        let mut opts = OpenOptions::default();
+        opts.write = true;
+        opts.create = true;
+        opts.truncate = true;
+        let mut file = fs_recovered
+            .open(&recovery_test_path, opts)
+            .await
+            .expect("Create post-crash file");
+        file.write_bytes(Bytes::from_static(b"Sanctum Crash Consistency Verified!"))
+            .await
+            .expect("Write post crash file");
+        file.flush().await.expect("Flush post crash file");
+    }
+
+    // Datei wieder einlesen
+    {
+        let mut opts = OpenOptions::default();
+        opts.read = true;
+        let mut file = fs_recovered
+            .open(&recovery_test_path, opts)
+            .await
+            .expect("Read post-crash file");
+        let bytes = file.read_bytes(1024).await.expect("Read bytes");
+        assert_eq!(&bytes[..], b"Sanctum Crash Consistency Verified!");
+    }
+
+    // Sauberes Aufräumen der Testdatei
+    drop(fs_recovered);
+    let _ = std::fs::remove_file(&container_path);
+}