Allow specifying db path and pool size

packages/duckdb-server-rust/Cargo.toml

@@ -19,6 +19,7 @@ async-trait = "0.1.83"
 axum = { version = "0.7", features = ["http1", "http2", "ws", "json", "tokio", "tracing", "macros"] }
 axum-server = { version = "0.7", features = ["tls-rustls"] }
 axum-server-dual-protocol = "0.7"
+clap = { version = "4.5.20", features = ["derive"] }
 duckdb = { version = "1", features = ["bundled", "csv", "json", "parquet", "url", "r2d2"] }
 futures = "0.3"
 listenfd = "1.0"

packages/duckdb-server-rust/src/app.rs

@@ -40,9 +40,11 @@ async fn handle_post(
     query::handle(&state, params).await
 }
 
-pub fn app() -> Result<Router> {
+pub fn app(db_path: &str, pool_size: u32) -> Result<Router> {
+    let effective_pool_size = if db_path == ":memory:" { 1 } else { pool_size };
+
     // Database and state setup
-    let db = ConnectionPool::new(":memory:", 1)?; // TODO: we can only use one connection since temp tables are scoped per connection
+    let db = ConnectionPool::new(db_path, effective_pool_size)?;
     let cache = lru::LruCache::new(1000.try_into()?);
 
     let state = Arc::new(AppState {

packages/duckdb-server-rust/src/main.rs

@@ -1,5 +1,6 @@
 use anyhow::Result;
 use axum_server::tls_rustls::RustlsConfig;
+use clap::Parser;
 use listenfd::ListenFd;
 use std::net::TcpListener;
 use std::{net::Ipv4Addr, net::SocketAddr, path::PathBuf};
@@ -14,8 +15,24 @@ mod interfaces;
 mod query;
 mod websocket;
 
+// Define command-line arguments using clap
+#[derive(Parser, Debug)]
+#[command(author, version, about)]
+struct Args {
+    /// Path to the DuckDB database file (default: ":memory:")
+    #[arg(short, long)]
+    db_path: Option<String>,
+
+    /// Size of the connection pool (default: 1)
+    #[arg(short, long, default_value_t = 1)]
+    pool_size: u32,
+}
+
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let args = Args::parse();
+    let db_path = args.db_path.unwrap_or_else(|| ":memory:".to_string());
+
     // Tracing setup
     tracing_subscriber::registry()
         .with(
@@ -27,7 +44,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         .init();
 
     // App setup
-    let app = app::app()?;
+    let app = app::app(&db_path, args.pool_size)?;
 
     // TLS configuration
     let mut config = RustlsConfig::from_pem_file(