[asterisk-commits] file: branch 12 r404027 - /branches/12/main/framehook.c

[SVN commits to the Asterisk project]

Author: file
Date: Tue Dec 17 12:25:26 2013
New Revision: 404027

URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=404027
Log:
framehooks: Re-iterate if framehook provides different frame.

Framehooks can be used in a reactive manner to execute specific logic
when a frame is received with a certain type and payload. Since it is
possible for framehooks to provide frames it was possible for this
reactive framehook to be unaware of frames it is looking for.

This change makes it so that when framehooks return a modified frame
the code will now re-iterate (from the beginning) and call any
previous framehooks that have not provided a modified frame themselves.

Review: https://reviewboard.asterisk.org/r/3046/

Modified:
    branches/12/main/framehook.c

Modified: branches/12/main/framehook.c
URL: http://svnview.digium.com/svn/asterisk/branches/12/main/framehook.c?view=diff&rev=404027&r1=404026&r2=404027
==============================================================================
--- branches/12/main/framehook.c (original)
+++ branches/12/main/framehook.c Tue Dec 17 12:25:26 2013
@@ -49,6 +49,9 @@
 };
 
 struct ast_framehook_list {
+	/*! the number of hooks currently present */
+	unsigned int count;
+	/*! id for next framehook added */
 	unsigned int id_count;
 	AST_LIST_HEAD_NOLOCK(, ast_framehook) list;
 };
@@ -73,21 +76,49 @@
 static struct ast_frame *framehook_list_push_event(struct ast_framehook_list *framehooks, struct ast_frame *frame, enum ast_framehook_event event)
 {
 	struct ast_framehook *framehook;
+	struct ast_frame *original_frame;
+	int *skip;
+	size_t skip_size;
 
 	if (!framehooks) {
 		return frame;
 	}
 
-	AST_LIST_TRAVERSE_SAFE_BEGIN(&framehooks->list, framehook, list) {
-		if (framehook->detach_and_destroy_me) {
-			/* this guy is signaled for destruction */
-			AST_LIST_REMOVE_CURRENT(list);
-			framehook_detach_and_destroy(framehook);
-		} else {
+	skip_size = sizeof(int) * framehooks->count;
+	skip = alloca(skip_size);
+	memset(skip, 0, skip_size);
+
+	do {
+		unsigned int num = 0;
+		original_frame = frame;
+
+		AST_LIST_TRAVERSE_SAFE_BEGIN(&framehooks->list, framehook, list) {
+			if (framehook->detach_and_destroy_me) {
+				/* this guy is signaled for destruction */
+				AST_LIST_REMOVE_CURRENT(list);
+				framehook_detach_and_destroy(framehook);
+				continue;
+			}
+
+			/* If this framehook has been marked as needing to be skipped, do so */
+			if (skip[num]) {
+				num++;
+				continue;
+			}
+
 			frame = framehook->i.event_cb(framehook->chan, frame, event, framehook->i.data);
-		}
-	}
-	AST_LIST_TRAVERSE_SAFE_END;
+
+			if (frame != original_frame) {
+				/* To prevent looping we skip any framehooks that have already provided a modified frame */
+				skip[num] = 1;
+				break;
+			}
+
+			num++;
+		}
+		AST_LIST_TRAVERSE_SAFE_END;
+	} while (frame != original_frame);
+
 	return frame;
 }
 
@@ -116,6 +147,7 @@
 		ast_channel_framehooks_set(chan, fh_list);
 	}
 
+	ast_channel_framehooks(chan)->count++;
 	framehook->id = ++ast_channel_framehooks(chan)->id_count;
 	AST_LIST_INSERT_TAIL(&ast_channel_framehooks(chan)->list, framehook, list);