cache result of (expensive) security check for visitor rights

begin tightening x-profile security

1 files changed, 28 insertions, 12 deletions

diff --git a/include/security.php b/include/security.php
index f37603916..5e79e1edd 100644
--- a/include/security.php
+++ b/include/security.php
@@ -2,15 +2,27 @@
 
 function can_write_wall(&$a,$owner) {
 
-        if((! (local_user())) && (! (remote_user())))
-                return false;
-		$uid = local_user();
+	static $verified = 0;
 
-        if(($uid) && ($uid == $owner)) {
-                return true;
-		}
+	if((! (local_user())) && (! (remote_user())))
+		return false;
+
+	$uid = local_user();
+
+	if(($uid) && ($uid == $owner)) {
+		return true;
+	}
+
+	if(remote_user()) {
 
-		if(remote_user()) {
+		// user remembered decision and avoid a DB lookup for each and every display item
+		// DO NOT use this function if there are going to be multiple owners
+
+		if($verified === 2)
+			return true;
+		elseif($verified === 1)
+			return false;
+		else {
 			$r = q("SELECT `contact`.*, `user`.`page-flags` FROM `contact` LEFT JOIN `user` on `user`.`uid` = `contact`.`uid` 
 				WHERE `contact`.`uid` = %d AND `contact`.`id` = %d AND `contact`.`blocked` = 0 AND `contact`.`pending` = 0 
 				AND `readonly` = 0  AND ( `contact`.`rel` IN ( %d , %d ) OR `user`.`page-flags` = %d ) LIMIT 1",
@@ -20,11 +32,15 @@ function can_write_wall(&$a,$owner) {
 				intval(REL_BUD),
 				intval(PAGE_COMMUNITY)
 			);
+			if(count($r)) {
+				$verified = 2;
+				return true;
+			}
+			else {
+				$verified = 1;
+			}
 		}
-		if(count($r))
-			return true;
-
-		
-        return false;
+	}
 
+	return false;
 }