xF: maintain an index of buffer by name

Imperceptibly improves performance, shortens source code.

xF.c

@@ -475,6 +475,7 @@ static struct
 
 	struct buffer *buffers;             ///< Ordered list of all buffers
 	struct buffer *buffers_tail;        ///< The tail of all buffers
+	struct str_map buffers_by_name;     ///< Buffers indexed by name
 	struct buffer *buffer_current;      ///< The current buffer
 	struct buffer *buffer_last;         ///< Last used buffer
 
@@ -1166,6 +1167,7 @@ app_reset_relay_state (void)
 	LIST_FOR_EACH (struct buffer, iter, g.buffers)
 		buffer_destroy (iter);
 	g.buffers = g.buffers_tail = NULL;
+	str_map_clear (&g.buffers_by_name);
 
 	str_map_free (&g.servers);
 	g.servers = str_map_make ((str_map_free_fn) server_destroy);
@@ -1245,15 +1247,6 @@ xui_request_attention (void)
 #endif
 }
 
-static struct buffer *
-buffer_find (const char *name)
-{
-	LIST_FOR_EACH (struct buffer, buffer, g.buffers)
-		if (!strcmp (buffer->buffer_name, name))
-			return buffer;
-	return NULL;
-}
-
 static void
 buffer_line_convert_items (struct buffer_line *line,
 	const union relay_item_data *items, uint32_t len)
@@ -1462,7 +1455,7 @@ relay_process_buffer_event (struct relay_event_message *m)
 	const char *buffer_name = relay_message_buffer_name (m);
 	hard_assert (buffer_name);
 
-	struct buffer *b = buffer_find (buffer_name);
+	struct buffer *b = str_map_find (&g.buffers_by_name, buffer_name);
 	if (!b)
 	{
 		if (m->data.event != RELAY_EVENT_BUFFER_UPDATE)
@@ -1473,6 +1466,7 @@ relay_process_buffer_event (struct relay_event_message *m)
 
 		b = buffer_new (buffer_name);
 		LIST_APPEND_WITH_TAIL (g.buffers, g.buffers_tail, b);
+		str_map_set (&g.buffers_by_name, b->buffer_name, b);
 	}
 
 	switch (m->data.event)
@@ -1490,11 +1484,13 @@ relay_process_buffer_event (struct relay_event_message *m)
 		b->highlighted = m->data.buffer_stats.highlighted;
 		break;
 	case RELAY_EVENT_BUFFER_RENAME:
-		free (b->buffer_name);
-		b->buffer_name = xstrdup (m->data.buffer_rename.new.str);
+		str_map_set (&g.buffers_by_name, b->buffer_name, NULL);
+		cstr_set (&b->buffer_name, xstrdup (m->data.buffer_rename.new.str));
+		str_map_set (&g.buffers_by_name, b->buffer_name, b);
 		break;
 	case RELAY_EVENT_BUFFER_REMOVE:
 		LIST_UNLINK_WITH_TAIL (g.buffers, g.buffers_tail, b);
+		str_map_set (&g.buffers_by_name, b->buffer_name, NULL);
 		if (g.buffer_current == b)
 			g.buffer_current = NULL;
 		if (g.buffer_last == b)
@@ -1872,17 +1868,6 @@ app_viewport_height (void)
 	return MAX (0, g_xui.height - 3 * g_xui.vunit);
 }
 
-static int
-app_buffer_list_content_height (void)
-{
-	size_t count = 0;
-	LIST_FOR_EACH (struct buffer, buffer, g.buffers)
-		count++;
-
-	uint64_t height = count * (uint64_t) g_xui.vunit;
-	return MIN ((uint64_t) INT_MAX, height);
-}
-
 static int *
 app_content_scroll_offset (void)
 {
@@ -1906,8 +1891,11 @@ static struct app_scroll_view
 app_scroll_view (enum app_widget_id id)
 {
 	if (id == WIDGET_BUFFER_LIST_SCROLLBAR)
+	{
+		size_t height = g.buffers_by_name.len * (size_t) g_xui.vunit;
 		return (struct app_scroll_view) { &g.buffer_list_offset,
-			app_buffer_list_content_height (), false };
+			MIN ((size_t) INT_MAX, height), false };
+	}
 
 	hard_assert (id == WIDGET_TRANSCRIPT_SCROLLBAR);
 	return (struct app_scroll_view) { app_content_scroll_offset (),
@@ -3581,7 +3569,8 @@ app_external_editor_process_file (void)
 		while (input.len && strchr ("\r\n", input.str[input.len - 1]))
 			input.str[--input.len] = 0;
 
-		struct buffer *buffer = buffer_find (g.editor_running_for);
+		struct buffer *buffer =
+			str_map_find (&g.buffers_by_name, g.editor_running_for);
 		if (buffer == g.buffer_current)
 			app_editor_set (input.str);
 		else if (buffer)
@@ -4338,6 +4327,7 @@ app_init_context (void)
 	g.relay.read_buffer = str_make ();
 	g.relay.write_buffer = str_make ();
 
+	g.buffers_by_name = str_map_make (NULL);
 	g.servers = str_map_make ((str_map_free_fn) server_destroy);
 }
 
@@ -4348,6 +4338,7 @@ app_free_context (void)
 	LIST_FOR_EACH (struct buffer_line, iter, g.local_lines)
 		buffer_line_destroy (iter);
 	g.local_lines = g.local_lines_tail = NULL;
+	str_map_free (&g.buffers_by_name);
 
 	log_view_free (&g.log);
 	str_map_free (&g.servers);