X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/e70dfa18fa10ef220799905cde86fae039a2a75d..0dafda7327014d7591df397cb9c54df8f172e677:/lib/lib.php

diff --git a/lib/lib.php b/lib/lib.php
index f34b09b7..91fe21b2 100644
--- a/lib/lib.php
+++ b/lib/lib.php
@@ -60,7 +60,7 @@
 	{
 		$sLoadAverage = file_get_contents('/proc/loadavg');
                 $aLoadAverage = explode(' ',$sLoadAverage);
-		return (int)$aLoadAverage[0];
+		return (float)$aLoadAverage[0];
 	}
 
 	function getProcessorCount()
@@ -917,3 +917,125 @@
                 return true;
         }
 
+	function getBucketMemcache()
+	{
+		static $m;
+
+		if (!CONST_ConnectionBucket_MemcacheServerAddress) return null;
+		if (!isset($m))
+		{
+		        $m = new Memcached();
+        		$m->addServer(CONST_ConnectionBucket_MemcacheServerAddress, CONST_ConnectionBucket_MemcacheServerPort);
+		}
+		return $m;
+	}
+
+	function doBucket($asKey, $iRequestCost, $iLeakPerSecond, $iThreshold)
+	{
+	        $m = getBucketMemcache();
+		if (!$m) return 0;
+
+		$iMaxVal = 0;
+	        $t = time();
+
+		foreach($asKey as $sKey)
+		{
+		        $aCurrentBlock = $m->get($sKey);
+	        	if (!$aCurrentBlock)
+			{
+		                $aCurrentBlock = array($iRequestCost, $t);
+        		}
+			else
+			{
+				// add RequestCost
+				// remove leak * the time since the last request 
+	        		$aCurrentBlock[0] += $iRequestCost - ($t - $aCurrentBlock[1])*$iLeakPerSecond;
+		        	$aCurrentBlock[1] = $t;
+			}
+
+	        	if ($aCurrentBlock[0] <= 0)
+			{
+                		$m->delete($sKey);
+		        }
+			else
+			{
+				// If we have hit the threshold stop and record this to the block list
+				if ($aCurrentBlock[0] >= $iThreshold)
+				{
+					$aCurrentBlock[0] = $iThreshold;
+
+					// Make up to 10 attempts to record this to memcache (with locking to prevent conflicts)
+					$i = 10;
+					for($i = 0; $i < 10; $i++)
+					{
+						$aBlockedList = $m->get('blockedList', null, $hCasToken);
+						if (!$aBlockedList)
+						{
+							$aBlockedList = array();
+							$m->add('blockedList', $aBlockedList);
+							$aBlockedList = $m->get('blockedList', null, $hCasToken);
+						}
+						if (!isset($aBlockedList[$sKey]))
+						{
+							$aBlockedList[$sKey] = array(1, $t);
+						}
+						else
+						{
+							$aBlockedList[$sKey][0]++;
+							$aBlockedList[$sKey][1] = $t;
+						}
+						$x = $m->cas($hCasToken, 'blockedList', $aBlockedList);
+						if ($x) break;
+					}
+				}
+				// Only keep in memcache until the time it would have expired (to avoid clutering memcache)
+	                	$m->set($sKey, $aCurrentBlock, $t + 1 + $aCurrentBlock[0]/$iLeakPerSecond);
+			}
+
+			// Bucket result in the largest bucket we find
+			$iMaxVal = max($iMaxVal, $aCurrentBlock[0]);
+		}
+
+		return $iMaxVal;
+        }
+
+	function byLastBlockTime($a, $b)
+	{
+		if ($a['lastBlockTimestamp'] == $b['lastBlockTimestamp'])
+		{
+			return 0;
+		}
+		return ($a['lastBlockTimestamp'] > $b['lastBlockTimestamp']) ? -1 : 1;
+	}
+
+	function getBucketBlocks()
+	{
+	        $m = getBucketMemcache();
+		if (!$m) return null;
+	        $t = time();
+		$aBlockedList = $m->get('blockedList', null, $hCasToken);
+		if (!$aBlockedList) $aBlockedList = array();
+		foreach($aBlockedList as $sKey => $aDetails)
+		{
+			$aCurrentBlock = $m->get($sKey);
+			if (!$aCurrentBlock) $aCurrentBlock = array(0, $t);
+			$iCurrentBucketSize = max(0, $aCurrentBlock[0] - ($t - $aCurrentBlock[1])*CONST_ConnectionBucket_LeakRate);
+			$aBlockedList[$sKey] = array(
+				'totalBlocks' => $aDetails[0],
+				'lastBlockTimestamp' => $aDetails[1],
+				'currentBucketSize' => $iCurrentBucketSize,
+				'lastRequestBlocked' => $aCurrentBlock[0] >= CONST_ConnectionBucket_BlockLimit,
+				'currentlyBlocked' => $iCurrentBucketSize + (CONST_ConnectionBucket_Cost_Reverse) >= CONST_ConnectionBucket_BlockLimit,
+				);
+		}
+		uasort($aBlockedList, 'byLastBlockTime');
+		return $aBlockedList;
+	}
+
+	function clearBucketBlocks()
+	{
+	        $m = getBucketMemcache();
+		if (!$m) return false;
+		$m->delete('blockedList');
+		return true;
+	}