From 181231f3ff9dce1d6edb3d264422bbc2a1bfe406 Mon Sep 17 00:00:00 2001
From: Devaev Maxim <mdevaev@gmail.com>
Date: Sun, 28 Mar 2021 21:51:34 +0300
Subject: [PATCH] common list operations

---
 src/libs/tools.h            | 34 ++++++++++++++++++++++++++++++++--
 src/ustreamer/http/server.c | 33 ++++++++-------------------------
 2 files changed, 40 insertions(+), 27 deletions(-)

diff --git a/src/libs/tools.h b/src/libs/tools.h
index c2b4416..157b0d5 100644
--- a/src/libs/tools.h
+++ b/src/libs/tools.h
@@ -35,6 +35,9 @@
 #include <sys/file.h>
 
 
+#define INLINE inline __attribute__((always_inline))
+#define UNUSED __attribute__((unused))
+
 #define A_CALLOC(_dest, _nmemb)		assert((_dest = calloc(_nmemb, sizeof(*(_dest)))))
 #define A_REALLOC(_dest, _nmemb)	assert((_dest = realloc(_dest, _nmemb * sizeof(*(_dest)))))
 #define MEMSET_ZERO(_obj)			memset(&(_obj), 0, sizeof(_obj))
@@ -43,8 +46,35 @@
 
 #define ARRAY_LEN(_array) (sizeof(_array) / sizeof(_array[0]))
 
-#define INLINE inline __attribute__((always_inline))
-#define UNUSED __attribute__((unused))
+#define LIST_ITERATE(_first, _item, ...) { \
+		for (__typeof__(_first) _item = _first; _item;) { \
+			__typeof__(_first) _next = _item->next; \
+			__VA_ARGS__ \
+			_item = _next; \
+		} \
+	}
+
+#define LIST_APPEND(_first, _item) { \
+		if (_first == NULL) { \
+			_first = _item; \
+		} else { \
+			__typeof__(_first) _last = _first; \
+			for (; _last->next; _last = _last->next); \
+			_item->prev = _last; \
+			_last->next = _item; \
+		} \
+	}
+
+#define LIST_REMOVE(_first, _item) { \
+		if (_item->prev == NULL) { \
+			_first = _item->next; \
+		} else { \
+			_item->prev->next = _item->next; \
+		} \
+		if (_item->next != NULL) { \
+			_item->next->prev = _item->prev; \
+		} \
+	}
 
 
 INLINE const char *bool_to_string(bool flag) {
diff --git a/src/ustreamer/http/server.c b/src/ustreamer/http/server.c
index 163b60f..4a594b9 100644
--- a/src/ustreamer/http/server.c
+++ b/src/ustreamer/http/server.c
@@ -93,13 +93,11 @@ void server_destroy(server_s *server) {
 	libevent_global_shutdown();
 #	endif
 
-	for (stream_client_s *client = RUN(stream_clients); client != NULL;) {
-		stream_client_s *next = client->next;
+	LIST_ITERATE(RUN(stream_clients), client, {
 		free(client->key);
 		free(client->hostport);
 		free(client);
-		client = next;
-	}
+	});
 
 	if (RUN(auth_token)) {
 		free(RUN(auth_token));
@@ -367,7 +365,7 @@ static void _http_callback_state(struct evhttp_request *request, void *v_server)
 		RUN(stream_clients_count)
 	));
 
-	for (stream_client_s * client = RUN(stream_clients); client != NULL; client = client->next) {
+	LIST_ITERATE(RUN(stream_clients), client, {
 		assert(evbuffer_add_printf(buf,
 			"\"%" PRIx64 "\": {\"fps\": %u, \"extra_headers\": %s, \"advance_headers\": %s,"
 			" \"dual_final_frames\": %s, \"zero_data\": %s}%s",
@@ -379,7 +377,7 @@ static void _http_callback_state(struct evhttp_request *request, void *v_server)
 			bool_to_string(client->zero_data),
 			(client->next ? ", " : "")
 		));
-	}
+	});
 
 	assert(evbuffer_add_printf(buf, "}}}}"));
 
@@ -477,15 +475,7 @@ static void _http_callback_stream(struct evhttp_request *request, void *v_server
 		client->hostport = _http_get_client_hostport(request);
 		client->id = get_now_id();
 
-		if (RUN(stream_clients) == NULL) {
-			RUN(stream_clients) = client;
-		} else {
-			stream_client_s *last = RUN(stream_clients);
-
-			for (; last->next != NULL; last = last->next);
-			client->prev = last;
-			last->next = client;
-		}
+		LIST_APPEND(RUN(stream_clients), client);
 		RUN(stream_clients_count) += 1;
 
 		if (RUN(stream_clients_count) == 1) {
@@ -673,14 +663,7 @@ static void _http_callback_stream_error(UNUSED struct bufferevent *buf_event, UN
 		evhttp_connection_free(conn);
 	}
 
-	if (client->prev == NULL) {
-		RUN(stream_clients) = client->next;
-	} else {
-		client->prev->next = client->next;
-	}
-	if (client->next != NULL) {
-		client->next->prev = client->prev;
-	}
+	LIST_REMOVE(RUN(stream_clients), client);
 	free(client->key);
 	free(client->hostport);
 	free(client);
@@ -692,7 +675,7 @@ static void _http_queue_send_stream(server_s *server, bool stream_updated, bool
 	bool has_clients = false;
 	bool queued = false;
 
-	for (stream_client_s *client = RUN(stream_clients); client != NULL; client = client->next) {
+	LIST_ITERATE(RUN(stream_clients), client, {
 		struct evhttp_connection *conn = evhttp_request_get_connection(client->request);
 		if (conn) {
 			// Фикс для бага WebKit. При включенной опции дропа одинаковых фреймов,
@@ -723,7 +706,7 @@ static void _http_queue_send_stream(server_s *server, bool stream_updated, bool
 
 			has_clients = true;
 		}
-	}
+	});
 
 	if (queued) {
 		static unsigned queued_fps_accum = 0;