refactor: accept arc reference for serve (#83)

* refactor: accept Arc<SessionContext> for serve

* chore: update readme

Author: sunng87

README.md

@@ -37,7 +37,7 @@ use datafusion::prelude::SessionContext;
 use datafusion_postgres::{serve, ServerOptions};
 
 // Create datafusion SessionContext
-let session_context = SessionContext::new();
+let session_context = Arc::new(SessionContext::new());
 // Configure your `session_context`
 // ...
 

datafusion-postgres-cli/src/main.rs

@@ -1,5 +1,6 @@
 use std::ffi::OsStr;
 use std::fs;
+use std::sync::Arc;
 
 use datafusion::execution::options::{
     ArrowReadOptions, AvroReadOptions, CsvReadOptions, NdJsonReadOptions, ParquetReadOptions,
@@ -184,7 +185,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         .with_host(opts.host)
         .with_port(opts.port);
 
-    serve(session_context, &server_options)
+    serve(Arc::new(session_context), &server_options)
         .await
         .map_err(|e| format!("Failed to run server: {}", e))?;
 

datafusion-postgres/src/handlers.rs

@@ -61,8 +61,7 @@ pub struct DfSessionService {
 }
 
 impl DfSessionService {
-    pub fn new(session_context: SessionContext) -> DfSessionService {
-        let session_context = Arc::new(session_context);
+    pub fn new(session_context: Arc<SessionContext>) -> DfSessionService {
         let parser = Arc::new(Parser {
             session_context: session_context.clone(),
         });

datafusion-postgres/src/lib.rs

@@ -37,7 +37,7 @@ impl Default for ServerOptions {
 
 /// Serve the Datafusion `SessionContext` with Postgres protocol.
 pub async fn serve(
-    session_context: SessionContext,
+    session_context: Arc<SessionContext>,
     opts: &ServerOptions,
 ) -> Result<(), std::io::Error> {
     // Create the handler factory with the session context and catalog name