--- admin.php	2009/04/01 09:30:42	1.60
+++ admin.php	2009/04/14 17:08:44	1.61
@@ -125,6 +125,11 @@
 $string['privilegedserverips']='Privileged server IPs';
 $string['configprivilegedserverips']='A comma-separated list of numerical IP addresses for OU servers that have privileged access to web services or other back-end communication.';
 
+$string['logbatchfolder']='Log batch folder';
+$string['configlogbatchfolder']='Disk folder used to batch up log inserts, specified as an absolute path. Leave blank to disable log insert batching. If specified, this <strong>must</strong> be on a local (not networked) disk, and must already exist.';
+$string['logbatchtime']='Log batch time';
+$string['configlogbatchtime']='Time in seconds to group log inserts into batches. (Note: In periods of low activity, inserts might be delayed longer because the batch insert only happens when there is another log request.)';
+
 $string['perflogview'] = 'Performance logs';
 $string['exportdisk'] = 'Bulk DVD Export';
 $string['sitemapgen'] = 'SEO Sitemap Generator';
--- server.php	2009/04/01 09:30:42	1.63
+++ server.php	2009/04/14 17:08:44	1.64
@@ -360,6 +360,14 @@
                                           get_string('configmemcachedpconn', 'admin'), 0,
                                           array( '0' => get_string('no'),
                                                  '1' => get_string('yes'))));
+// ou-specific begins
+$temp->add(new admin_setting_configtext('logbatchfolder',
+    get_string('logbatchfolder', 'admin'),
+    get_string('configlogbatchfolder','admin'),''));
+$temp->add(new admin_setting_configtext('logbatchtime',
+    get_string('logbatchtime', 'admin'),
+    get_string('configlogbatchtime','admin'),'30'));
+// ou-specific ends
 $ADMIN->add('server', $temp);
 
 if ($CFG->dbfamily === 'mysql') {
--- ou_lib.php	2009/03/03 10:50:38	1.6
+++ ou_lib.php	2009/04/14 17:08:44	1.7
@@ -136,4 +136,95 @@
         
         return true;
      }
+
+/**
+ * For use with very frequent SQL inserts. Batches them up into a file in 
+ * local filesystem which is inserted in a single transaction after a number
+ * of seconds (when a future insert happens).
+ * 
+ * @param string $table Name of table (unique identifier for type of insert)
+ * @param string $sql SQL of insert command
+ */
+function ou_run_batched_insert($table, $sql) {
+    global $CFG, $db;
+
+    // If not enabled, run SQL statement directly
+    if (empty($CFG->logbatchfolder) || empty($CFG->logbatchtime)) {
+        if(!$db->Execute($sql)) {
+            debugging("Insert into $table failed [$sql]");
+        }
+        return;
+    }
+
+    // Otherwise batch together inserts over a period of time using filesystem    
+    $logtimefile = $CFG->logbatchfolder . '/' . $table . '.time';
+    $logbatchfile = $CFG->logbatchfolder . '/' . $table . '.batch';
+
+    // Open batch file (this should lock it)
+    if ($handle = fopen($logbatchfile, 'a+')) {
+        // Get modified time of time file and create it if it doesn't exist
+        if (!($modified = @filemtime($logtimefile))) {
+            file_put_contents($logtimefile, 
+                'This file tracks when update batch was last applied');
+            $modified = time();
+        }
+
+        // See how long since we've updated
+        if (time() - $modified < $CFG->logbatchtime) {
+            // It isn't long since we updated, so just add the current
+            // function call to the file
+            fwrite($handle, strlen($sql) . ':' . $sql);
+            fclose($handle);
+            return;
+        } else {
+            // It's a while since we updated, so read the whole file and
+            // update it. First read the data
+            touch($logtimefile);
+            fseek($handle, 0);
+            $size = filesize($logbatchfile);
+            if($size > 0) {
+                $data = fread($handle, $size);
+                // Clear and close the file now so it doesn't stay locked long
+                ftruncate($handle, 0);
+            } else {
+                $data = '';
+            }
+            fclose($handle);
+
+            // Start batch
+            begin_sql();
+
+            // Process the data
+            while($data !== '') {
+                // Get data chunk
+                $colon = strpos($data, ':');
+                if($colon === false) {
+                    debugging('Error: invalid log batch format');
+                    break;
+                } 
+                $bytes = (int)substr($data, 0, $colon);
+                $batchsql = substr($data, $colon + 1, $bytes);
+                $data = (string)substr($data, $colon + 1 + $bytes);
+
+                // Execute SQL
+                if(!$db->Execute($batchsql)) {
+                    debugging("Insert into $table failed [$batchsql]");
+                }
+            }
+
+            // Finally don't forget to actually log *this* request too
+            if(!$db->Execute($sql)) {
+                debugging("Insert into $table failed [$sql]");
+            }
+
+            // Finish batch
+            commit_sql();
+        }
+    } else {
+        debugging('Failed to open log batch file');
+        if(!$db->Execute($sql)) {
+            debugging("Insert into $table failed [$sql]");
+        }
+    }
+}
 ?>
--- datalib.php	2009/03/17 16:28:52	1.103
+++ datalib.php	2009/04/14 17:08:44	1.104
@@ -2249,7 +2248,11 @@
     }
     $sql ='INSERT INTO '. $CFG->prefix .'log (time, userid, course, ip, module, cmid, action, url, info)
         VALUES (' . "'$timenow', '$userid', '$courseid', '$REMOTE_ADDR', '$module', '$cm', '$action', '$url', '$info')";
-
+// ou-specific begins
+    ou_run_batched_insert('log', $sql);
+    return;
+// ou-specific ends
+    
     $result = $db->Execute($sql);
 
     // MDL-11893, alert $CFG->supportemail if insert into log failed