Port httpserver extension to DuckDB v1.5.4. (#52)

* Port httpserver extension to DuckDB v1.5.4.

Update duckdb and extension-ci-tools submodules, pin CI workflows to v1.5.4, and fix a crash in httpserve_start caused by a dangling ExtensionLoader reference.

* Fix Linux CI segfault by using synchronous httplib task queue.

OpenSSL-enabled httplib runs request handlers in a thread pool by default, which can crash with statically linked OpenSSL on Linux amd64. Handle requests on the server thread instead.

Author: lmangani

.github/workflows/MainDistributionPipeline.yml

@@ -13,8 +13,8 @@ concurrency:
 jobs:
   duckdb-stable-build:
     name: Build extension binaries
-    uses: duckdb/extension-ci-tools/.github/workflows/_extension_distribution.yml@main
+    uses: duckdb/extension-ci-tools/.github/workflows/_extension_distribution.yml@v1.5.4
     with:
-      duckdb_version: main
-      ci_tools_version: main
+      duckdb_version: v1.5.4
+      ci_tools_version: v1.5.4
       extension_name: httpserver

duckdb

@@ -26,6 +26,23 @@ namespace duckdb
 
 	using namespace duckdb_yyjson; // NOLINT(*-build-using-namespace)
 
+	// httplib defaults to a thread pool when OpenSSL is enabled. With statically
+	// linked OpenSSL on Linux this can segfault in worker threads, so handle
+	// requests synchronously on the server thread instead.
+	class SynchronousTaskQueue : public duckdb_httplib_openssl::TaskQueue
+	{
+	public:
+		bool enqueue(std::function<void()> fn) override
+		{
+			fn();
+			return true;
+		}
+
+		void shutdown() override
+		{
+		}
+	};
+
 	struct HttpServerState
 	{
 		std::unique_ptr<duckdb_httplib_openssl::Server> server;
@@ -384,6 +401,12 @@ namespace duckdb
 			std::string error_message = "DB::Exception: " + std::string(ex.what());
 			res.set_content(error_message, "text/plain");
 		}
+		catch (const std::exception &ex)
+		{
+			res.status = 500;
+			std::string error_message = "DB::Exception: " + std::string(ex.what());
+			res.set_content(error_message, "text/plain");
+		}
 	}
 
 	void HttpServerStart(shared_ptr<DatabaseInstance> db, string_t host, int32_t port, string_t auth = string_t())
@@ -395,6 +418,7 @@ namespace duckdb
 
 		global_state.db_instance = db;
 		global_state.server = make_uniq<duckdb_httplib_openssl::Server>();
+		global_state.server->new_task_queue = []() { return new SynchronousTaskQueue(); };
 		global_state.is_running = true;
 		global_state.auth_token = auth.GetString();
 
@@ -580,9 +604,10 @@ namespace duckdb
 
 	static void LoadInternal(ExtensionLoader &loader)
 	{
+		auto db = loader.GetDatabaseInstance().shared_from_this();
 		auto httpserve_start = ScalarFunction(
 				"httpserve_start", {LogicalType::VARCHAR, LogicalType::INTEGER, LogicalType::VARCHAR}, LogicalType::VARCHAR,
-				[&](DataChunk &args, ExpressionState &state, Vector &result)
+				[db](DataChunk &args, ExpressionState &state, Vector &result)
 				{
 					auto &host_vector = args.data[0];
 					auto &port_vector = args.data[1];
@@ -592,7 +617,7 @@ namespace duckdb
 																										 {
 			    auto port = ((int32_t *)port_vector.GetData())[0];
 			    auto auth = ((string_t *)auth_vector.GetData())[0];
-			    HttpServerStart(loader.GetDatabaseInstance().shared_from_this(), host, port, auth);
+			    HttpServerStart(db, host, port, auth);
 			    return StringVector::AddString(result, "HTTP server started on " + host.GetString() + ":" +
 			                                               std::to_string(port)); });
 				});