decouple-service-from-fd-array-index.patch

This patch removes the relationship between position in the
pollfd[] array and any meaning about the type of socket.

It also refactors the service loop so there is a per-fd
function that detects the mode of the connection and services
it accordingly.

The context wsi * array is removed and a hashtable introduced
allowing fast wsi lookup from just the fd that it is
associated with

Signed-off-by: Andy Green <andy@warmcat.com>

lib/client-handshake.c

@@ -50,11 +50,10 @@ libwebsocket_client_close(struct libwebsocket *wsi)
 		clients = wsi->protocol->owning_server;
 		if (clients)
 			for (n = 0; n < clients->fds_count; n++) {
-				if (clients->wsi[n] != wsi)
+				if (clients->fds[n].fd != wsi->sock)
 					continue;
 				while (n < clients->fds_count - 1) {
 					clients->fds[n] = clients->fds[n + 1];
-					clients->wsi[n] = clients->wsi[n + 1];
 					n++;
 				}
 				/* we only have to deal with one */
@@ -150,8 +149,6 @@ libwebsocket_client_connect(struct libwebsocket_context *this,
 		return NULL;
 	}
 
-	this->wsi[this->fds_count] = wsi;
-
 	/* -1 means just use latest supported */
 
 	if (ietf_version_or_minus_one == -1)
@@ -225,6 +222,7 @@ libwebsocket_client_connect(struct libwebsocket_context *this,
 		goto bail1;
 	}
 
+	insert_wsi(this, wsi);
 
 	server_addr.sin_family = AF_INET;
 	server_addr.sin_port = htons(port);

lib/parsers.c

@@ -1143,6 +1143,8 @@ int libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf,
 					*/
 					buf[0] = 'C';
 					break;
+				default:
+					break;
 				}
 			}
 			break;

lib/private-libwebsockets.h

@@ -68,7 +68,7 @@ static inline void debug(const char *format, ...)
 }
 #endif
 
-
+#define FD_HASHTABLE_MODULUS 32
 #define MAX_CLIENTS 100
 #define LWS_MAX_HEADER_NAME_LENGTH 64
 #define LWS_MAX_HEADER_LEN 4096
@@ -166,11 +166,29 @@ struct lws_tokens {
 	int token_len;
 };
 
+enum connection_mode {
+	LWS_CONNMODE_WS_SERVING,
+	LWS_CONNMODE_WS_CLIENT,
+
+	/* special internal types */
+	LWS_CONNMODE_SERVER_LISTENER,
+	LWS_CONNMODE_BROADCAST_PROXY_LISTENER,
+	LWS_CONNMODE_BROADCAST_PROXY
+};
+
+
+#define LWS_FD_HASH(fd) ((fd ^ (fd >> 8) ^ (fd >> 16)) % FD_HASHTABLE_MODULUS)
+
+struct libwebsocket_fd_hashtable {
+	struct libwebsocket *wsi[MAX_CLIENTS + 1];
+	int length;
+};
+
 struct libwebsocket_protocols;
 
 struct libwebsocket_context {
-	struct libwebsocket *wsi[MAX_CLIENTS + 1];
-	struct pollfd fds[MAX_CLIENTS + 1];
+	struct libwebsocket_fd_hashtable fd_hashtable[FD_HASHTABLE_MODULUS];
+	struct pollfd fds[MAX_CLIENTS * FD_HASHTABLE_MODULUS + 1];
 	int fds_count;
 	int listen_port;
 	char http_proxy_address[256];
@@ -189,10 +207,6 @@ struct libwebsocket_context {
 	int count_protocols;
 };
 
-enum connection_mode {
-	LWS_CONNMODE_WS_SERVING,
-	LWS_CONNMODE_WS_CLIENT,
-};
 
 
 /*
@@ -215,6 +229,7 @@ struct libwebsocket {
 	char rx_user_buffer[LWS_SEND_BUFFER_PRE_PADDING + MAX_USER_RX_BUFFER +
 						  LWS_SEND_BUFFER_POST_PADDING];
 	int rx_user_buffer_head;
+	int protocol_index_for_broadcast_proxy;
 
 	int sock;
 
@@ -279,3 +294,12 @@ xor_mask_04(struct libwebsocket *wsi, unsigned char c);
 
 extern unsigned char
 xor_mask_05(struct libwebsocket *wsi, unsigned char c);
+
+extern struct libwebsocket *
+wsi_from_fd(struct libwebsocket_context *this, int fd);
+
+extern int
+insert_wsi(struct libwebsocket_context *this, struct libwebsocket *wsi);
+
+extern int
+delete_from_fd(struct libwebsocket_context *this, int fd);

libwebsockets-api-doc.html

@@ -67,6 +67,13 @@ nothing is pending, or as soon as it services whatever was pending.
 <dt><b>wsi</b>
 <dd>Websocket connection instance to get callback for
 </dl>
+<h3>Description</h3>
+<blockquote>
+<p>
+This only works for internal <b>poll</b> management, (ie, calling the libwebsocket
+service loop, you will have to make your own arrangements if your <b>poll</b>
+loop is managed externally.
+</blockquote>
 <hr>
 <h2>libwebsocket_callback_on_writable_all_protocol - Request a callback for all connections using the given protocol when it becomes possible to write to each socket without blocking in turn.</h2>
 <i>int</i>
@@ -77,6 +84,13 @@ nothing is pending, or as soon as it services whatever was pending.
 <dt><b>protocol</b>
 <dd>Protocol whose connections will get callbacks
 </dl>
+<h3>Description</h3>
+<blockquote>
+<p>
+This only works for internal <b>poll</b> management, (ie, calling the libwebsocket
+service loop, you will have to make your own arrangements if your <b>poll</b>
+loop is managed externally.
+</blockquote>
 <hr>
 <h2>libwebsocket_get_socket_fd - returns the socket file descriptor</h2>
 <i>int</i>
@@ -110,6 +124,10 @@ You will not need this unless you are doing something special
 <p>
 If the output side of a server process becomes choked, this allows flow
 control for the input side.
+<p>
+This only works for internal <b>poll</b> management, (ie, calling the libwebsocket
+service loop, you will have to make your own arrangements if your <b>poll</b>
+loop is managed externally.
 </blockquote>
 <hr>
 <h2>libwebsocket_canonical_hostname - returns this host's hostname</h2>