libsql: Add local encryption example

Author: penberg

libsql/examples/encryption_local.rs

@@ -0,0 +1,67 @@
+// Example of using offline writes with encryption
+
+use libsql::{params, Builder};
+use libsql::{EncryptionConfig, Cipher};
+
+#[tokio::main]
+async fn main() {
+    tracing_subscriber::fmt::init();
+
+    // The local database path where the data will be stored.
+    let db_path = std::env::var("LIBSQL_DB_PATH").unwrap();
+
+    // The encryption key for the database.
+    let encryption_key = std::env::var("LIBSQL_ENCRYPTION_KEY").unwrap();
+
+    let mut db_builder = Builder::new_local(db_path);
+
+    db_builder = db_builder.encryption_config(EncryptionConfig {
+        cipher: Cipher::Aes256Cbc,
+        encryption_key: encryption_key.into(),
+    });
+
+    let db = match db_builder.build().await {
+        Ok(db) => db,
+        Err(error) => {
+            return;
+        }
+    };
+
+    let conn = db.connect().unwrap();
+
+    conn.execute("ATTACH DATABASE 'world.db' AS world KEY secret", ()).await.unwrap();
+
+    conn.execute(
+        r#"
+        CREATE TABLE IF NOT EXISTS guest_book_entries (
+            text TEXT
+        )"#,
+        (),
+    )
+    .await
+    .unwrap();
+
+    let mut input = String::new();
+    println!("Please write your entry to the guestbook:");
+    match std::io::stdin().read_line(&mut input) {
+        Ok(_) => {
+            println!("You entered: {}", input);
+            let params = params![input.as_str()];
+            conn.execute("INSERT INTO guest_book_entries (text) VALUES (?)", params)
+                .await
+                .unwrap();
+        }
+        Err(error) => {
+            eprintln!("Error reading input: {}", error);
+        }
+    }
+    let mut results = conn
+        .query("SELECT * FROM guest_book_entries", ())
+        .await
+        .unwrap();
+    println!("Guest book entries:");
+    while let Some(row) = results.next().await.unwrap() {
+        let text: String = row.get(0).unwrap();
+        println!("  {}", text);
+    }
+}