Add WebSocket support and enhance chat functionality

- Implement WebSocket handling in the FastCGI server, allowing for real-time communication.
- Introduce functions for managing WebSocket connections, broadcasting messages, and sending to specific connections.
- Create a chat interface in the `websockets.ws.uce` file, including message handling and user notifications.
- Refactor existing code to accommodate WebSocket integration, ensuring compatibility with HTTP requests.
- Update documentation to reflect new features and usage instructions for WebSocket functionality.

src/lib/compiler.cpp

@@ -202,6 +202,7 @@ void load_shared_unit(Request* context, SharedUnit* su, String file_name)
 	//setup_unit_paths(context, su, file_name);
 
 	su->on_render = 0;
+	su->on_websocket = 0;
 	su->on_setup = 0;
 	su->compiler_messages = "";
 
@@ -223,6 +224,9 @@ void load_shared_unit(Request* context, SharedUnit* su, String file_name)
 		if ((error = dlerror()) != NULL)
 			printf("Error - %s in %s\n", error, su->file_name.c_str());
 		su->on_render = (call_handler)dlsym(su->so_handle, "render");
+		dlerror();
+		su->on_websocket = (call_handler)dlsym(su->so_handle, "websocket");
+		dlerror();
 		su->api_declarations = split(file_get_contents(su->api_file_name), "\n");
 		//else
 		//	printf("(i) loaded unit %s\n", su->file_name.c_str());
@@ -403,6 +407,31 @@ void compiler_invoke(Request* context, String file_name, DTree& call_param)
 	}
 }
 
+void compiler_invoke_websocket(Request* context, String file_name, DTree& call_param)
+{
+	auto su = compiler_load_shared_unit(context, file_name, "", false);
+	if(!su)
+		return;
+
+	if(!su->on_setup)
+	{
+		printf("internal error: set_current_request() not defined in %s\n", file_name.c_str());
+		return;
+	}
+
+	if(!su->on_websocket)
+	{
+		printf("no WS() entry point in %s\n", file_name.c_str());
+		return;
+	}
+
+	String prev_wd = get_cwd();
+	set_cwd(su->src_path);
+	su->on_setup(context);
+	su->on_websocket(call_param);
+	set_cwd(prev_wd);
+}
+
 void render_file(String file_name)
 {
 	//printf("(i) render_file(%s)\n", file_name.c_str());
@@ -461,4 +490,3 @@ DTree* call_file(String file_name, String function_name, DTree* call_param)
 	}
 	return(result);
 }
-

src/lib/compiler.h

@@ -1,4 +1,5 @@
 #define RENDER() extern "C" void render(DTree& call)
+#define WS() extern "C" void websocket(DTree& call)
 #define EXPORT extern "C"
 
 String process_html_literal(Request* context, SharedUnit* su, String content);
@@ -8,6 +9,7 @@ void load_shared_unit(Request* context, SharedUnit* su, String file_name);
 void compile_shared_unit(Request* context, SharedUnit* su, String file_name);
 SharedUnit* get_shared_unit(Request* context, String file_name, bool opt_so_optional = false);
 void compiler_invoke(Request* context, String file_name, DTree& call_param);
+void compiler_invoke_websocket(Request* context, String file_name, DTree& call_param);
 SharedUnit* compiler_load_shared_unit(Request* context, String file_name, String current_path = "", bool opt_so_optional = false);
 
 SharedUnit* load_file(String file_name);

src/lib/sys.cpp

@@ -431,7 +431,7 @@ std::map<pid_t, Worker> workers;
 #include <sys/resource.h>
 #include <sys/prctl.h>
 
-void spawn_subprocess(std::function<void()> exec_after_spawn)
+pid_t spawn_subprocess(std::function<void()> exec_after_spawn)
 {
 	parent_pid = getpid();
 	pid_t p;
@@ -442,6 +442,7 @@ void spawn_subprocess(std::function<void()> exec_after_spawn)
 		//printf("(C) child procress started, PID:%i\n", my_pid);
 		prctl(PR_SET_PDEATHSIG, SIGHUP);
 		exec_after_spawn();
+		return(0);
 	}
 	else
 	{
@@ -449,6 +450,7 @@ void spawn_subprocess(std::function<void()> exec_after_spawn)
 		w.pid = p;
 		workers[w.pid] = w;
 		printf("(P) child procress spawned: PID %i\n", p);
+		return(p);
 	}
 }
 

src/lib/sys.h

@@ -36,6 +36,16 @@ void socket_close(u64 sockfd);
 bool socket_write(u64 sockfd, String data);
 String socket_read(u64 sockfd, u32 max_length = 1024*128, u32 timeout = 1);
 
+String ws_message();
+String ws_connection_id();
+String ws_scope();
+StringList ws_connections(String scope = "");
+u64 ws_connection_count(String scope = "");
+bool ws_send(String message, String scope = "");
+u64 ws_broadcast(String message, String scope = "");
+bool ws_send_to(String connection_id, String message);
+bool ws_close(String connection_id = "");
+
 String memcache_escape_key(String key);
 StringList memcache_escape_keys(StringList keys);
 u64 memcache_connect(String host = "127.0.0.1", short port = 11211);

src/lib/types.cpp

@@ -47,7 +47,10 @@ void Request::ob_start()
 
 Request::~Request()
 {
+	for(auto* stream : ob_stack)
+		delete stream;
+	ob_stack.clear();
+	ob = 0;
 	for(auto& sockfd : resources.sockets)
 		close(sockfd);
 }
-

src/lib/types.h

@@ -78,6 +78,7 @@ struct SharedUnit {
 
 	request_handler on_setup;
 	call_handler on_render;
+	call_handler on_websocket;
 
 	String compiler_messages;
 	time_t last_compiled;
@@ -169,6 +170,9 @@ struct Request {
 		std::vector<void*> mysql_connections;
 		u64 client_socket = 0;
 		u64 server_socket = 0;
+		bool is_websocket = false;
+		String websocket_connection_id = "";
+		String websocket_scope = "";
 		std::string params_buffer;
 	} resources;
 

src/lib/uri.cpp

@@ -1,5 +1,32 @@
 #include "uri.h"
 
+static String base64_encode(String raw)
+{
+	static const char* chars =
+		"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+		"abcdefghijklmnopqrstuvwxyz"
+		"0123456789+/";
+
+	String result;
+	int val = 0;
+	int bits = -6;
+	for(unsigned char c : raw)
+	{
+		val = (val << 8) + c;
+		bits += 8;
+		while(bits >= 0)
+		{
+			result.append(1, chars[(val >> bits) & 0x3F]);
+			bits -= 6;
+		}
+	}
+	if(bits > -6)
+		result.append(1, chars[((val << 8) >> (bits + 8)) & 0x3F]);
+	while(result.length() % 4 != 0)
+		result.append(1, '=');
+	return(result);
+}
+
 String var_dump(URI uri, String prefix, String postfix)
 {
 	return(
@@ -427,3 +454,106 @@ void session_destroy(String session_name)
 		context->session_id = "";
 	}
 }
+
+String ws_make_accept_key(String client_key)
+{
+	return(base64_encode(gen_sha1(
+		client_key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11",
+		true
+	)));
+}
+
+String ws_encode_frame(String payload, u8 opcode, bool is_final_fragment)
+{
+	String frame;
+	u8 first_byte = opcode & 0x0F;
+	if(is_final_fragment)
+		first_byte |= 0x80;
+	frame.append(1, first_byte);
+
+	u64 payload_length = payload.length();
+	if(payload_length <= 125)
+	{
+		frame.append(1, (char)payload_length);
+	}
+	else if(payload_length <= 0xFFFF)
+	{
+		frame.append(1, 126);
+		frame.append(1, (char)((payload_length >> 8) & 0xFF));
+		frame.append(1, (char)(payload_length & 0xFF));
+	}
+	else
+	{
+		frame.append(1, 127);
+		for(int shift = 56; shift >= 0; shift -= 8)
+			frame.append(1, (char)((payload_length >> shift) & 0xFF));
+	}
+
+	frame += payload;
+	return(frame);
+}
+
+String ws_close_frame(u16 status_code, String reason)
+{
+	String payload;
+	payload.append(1, (char)((status_code >> 8) & 0xFF));
+	payload.append(1, (char)(status_code & 0xFF));
+	payload += reason;
+	return(ws_encode_frame(payload, 0x8));
+}
+
+bool WSFrame::parse(const String& buffer, String& error)
+{
+	error = "";
+	payload = "";
+
+	if(buffer.length() < 2)
+		return(false);
+
+	const unsigned char* raw = (const unsigned char*)buffer.data();
+	opcode = raw[0] & 0x0F;
+	is_final_fragment = (raw[0] & 0x80) != 0;
+	mask_bit = (raw[1] & 0x80) != 0;
+	payload_length = raw[1] & 0x7F;
+	header_length = 2;
+
+	if(payload_length == 126)
+	{
+		if(buffer.length() < 4)
+			return(false);
+		payload_length = ((u64)raw[2] << 8) | (u64)raw[3];
+		header_length = 4;
+	}
+	else if(payload_length == 127)
+	{
+		if(buffer.length() < 10)
+			return(false);
+		payload_length = 0;
+		for(u32 i = 0; i < 8; i++)
+			payload_length = (payload_length << 8) | (u64)raw[2 + i];
+		header_length = 10;
+	}
+
+	u64 mask_offset = header_length;
+	if(mask_bit)
+		header_length += 4;
+
+	frame_length = header_length + payload_length;
+	if(frame_length < header_length)
+	{
+		error = "invalid websocket frame length";
+		return(false);
+	}
+	if(buffer.length() < frame_length)
+		return(false);
+
+	payload.assign(buffer.data() + header_length, payload_length);
+	if(mask_bit)
+	{
+		const unsigned char* mask = raw + mask_offset;
+		for(u64 i = 0; i < payload.length(); i++)
+			payload[i] = payload[i] ^ mask[i % 4];
+	}
+
+	return(true);
+}

src/lib/uri.h

@@ -17,69 +17,20 @@ StringMap load_session_data(String session_id);
 void save_session_data(String session_id, StringMap data);
 String session_start(String session_name = "uce-session");
 void session_destroy(String session_name = "uce-session");
+String ws_make_accept_key(String client_key);
+String ws_encode_frame(String payload, u8 opcode = 0x1, bool is_final_fragment = true);
+String ws_close_frame(u16 status_code = 1000, String reason = "");
 
 struct WSFrame {
 
-	u8 opcode;
-	u8 is_final_fragment;
-	u8 mask_bit;
-	u64 payload_length;
-	u64 offset;
-	u8* payload;
+	u8 opcode = 0;
+	bool is_final_fragment = false;
+	bool mask_bit = false;
+	u64 payload_length = 0;
+	u64 header_length = 0;
+	u64 frame_length = 0;
+	String payload;
 
-	WSFrame(String& bufstr)
-	{
-		const char* buffer = bufstr.c_str();
-		u64 buffer_size = bufstr.size();
-		opcode = buffer[0] & 0x0F;
-		is_final_fragment = buffer[0] & 0x80;
-		mask_bit = buffer[1] & 0x80;
-		payload_length = buffer[1] & 0x7F;
-
-		offset = 2;
-		if (payload_length == 126) {
-			payload_length = ((u64) buffer[2] << 8) | buffer[3];
-			offset = 4;
-		} else if (payload_length == 127) {
-			payload_length = ((u64) buffer[2] << 56) |
-				((u64) buffer[3] << 48) |
-				((u64) buffer[4] << 40) |
-				((u64) buffer[5] << 32) |
-				((u64) buffer[6] << 24) |
-				((u64) buffer[7] << 16) |
-				((u64) buffer[8] << 8) |
-				buffer[9];
-			offset = 10;
-		}
-
-		uint8_t* maskingKey = nullptr;
-		if (mask_bit) {
-			maskingKey = reinterpret_cast<uint8_t*>(const_cast<char*>(buffer + offset));
-			offset += 4;
-		}
-
-		// Parse the frame payload
-		payload = reinterpret_cast<uint8_t*>(const_cast<char*>(buffer + offset));
-		if (mask_bit) {
-			for (int i = 0; i < payload_length; i++) {
-				payload[i] = payload[i] ^ maskingKey[i % 4];
-			}
-		}
-
-		// Print the parsed frame
-		std::cout << "Parsed WebSocket frame:" << std::endl;
-		std::cout << "  Opcode: " << (int) opcode << std::endl;
-		std::cout << "  Is final fragment: " << (is_final_fragment ? "true" : "false") << std::endl;
-		std::cout << "  Payload length: " << payload_length << std::endl;
-		if (mask_bit) {
-			std::cout << "  Masking key: ";
-			for (int i = 0; i < 4; i++) {
-				std::cout << std::hex << (int) maskingKey[i] << " ";
-			}
-			std::cout << std::endl;
-		}
-		std::cout << "  Payload: " << std::endl << std::string((const char*) payload, payload_length) << std::endl;
-
-	}
+	bool parse(const String& buffer, String& error);
 
 };