Stop caching unfindable keys

There were some problems with the automated cache/uncache system
for data objects that made us cache unfindable keys (with null
attributes and sometimes null names). Fixed those problems and
refactored the encache() and decache() methods so they use a helper
to find the cache keys to use.

diff --git a/classes/Memcached_DataObject.php b/classes/Memcached_DataObject.php
index 1608720d14072980187db8ba0cfb682a9d2d0334..020d813b2c4787b8a2e6439decd806e8023f9987 100644 (file)
--- a/classes/Memcached_DataObject.php
+++ b/classes/Memcached_DataObject.php
@@ -152,52 +152,69 @@ class Memcached_DataObject extends DB_DataObject
     function encache()
     {
         $c = $this->memcache();
+
         if (!$c) {
             return false;
-        } else {
-            $pkey = array();
-            $pval = array();
-            $types = $this->keyTypes();
-            ksort($types);
-            foreach ($types as $key => $type) {
-                if ($type == 'K') {
-                    $pkey[] = $key;
-                    $pval[] = $this->$key;
-                } else {
-                    $c->set($this->cacheKey($this->tableName(), $key, $this->$key), $this);
-                }
-            }
-            # XXX: should work for both compound and scalar pkeys
-            $pvals = implode(',', $pval);
-            $pkeys = implode(',', $pkey);
-            $c->set($this->cacheKey($this->tableName(), $pkeys, $pvals), $this);
+        }
+
+        $keys = $this->_allCacheKeys();
+
+        foreach ($keys as $key) {
+            $c->set($key, $this);
         }
     }
 
     function decache()
     {
         $c = $this->memcache();
+
         if (!$c) {
             return false;
-        } else {
-            $pkey = array();
-            $pval = array();
-            $types = $this->keyTypes();
-            ksort($types);
-            foreach ($types as $key => $type) {
-                if ($type == 'K') {
-                    $pkey[] = $key;
-                    $pval[] = $this->$key;
-                } else {
-                    $c->delete($this->cacheKey($this->tableName(), $key, $this->$key));
+        }
+
+        $keys = $this->_allCacheKeys();
+
+        foreach ($keys as $key) {
+            $c->delete($key, $this);
+        }
+    }
+
+    function _allCacheKeys()
+    {
+        $ckeys = array();
+
+        $types = $this->keyTypes();
+        ksort($types);
+
+        $pkey = array();
+        $pval = array();
+
+        foreach ($types as $key => $type) {
+
+            assert(!empty($key));
+
+            if ($type == 'U') {
+                if (empty($this->$key)) {
+                    continue;
                 }
+                $ckeys[] = $this->cacheKey($this->tableName(), $key, $this->$key);
+            } else if ($type == 'K' || $type == 'N') {
+                $pkey[] = $key;
+                $pval[] = $this->$key;
+            } else {
+                throw new Exception("Unknown key type $key => $type for " . $this->tableName());
             }
-            # should work for both compound and scalar pkeys
-            # XXX: comma works for now but may not be safe separator for future keys
-            $pvals = implode(',', $pval);
-            $pkeys = implode(',', $pkey);
-            $c->delete($this->cacheKey($this->tableName(), $pkeys, $pvals));
         }
+
+        assert(count($pkey) > 0);
+
+        // XXX: should work for both compound and scalar pkeys
+        $pvals = implode(',', $pval);
+        $pkeys = implode(',', $pkey);
+
+        $ckeys[] = $this->cacheKey($this->tableName(), $pkeys, $pvals);
+
+        return $ckeys;
     }
 
     function multicache($cls, $kv)