+ * @param int|string $key The cache key to decrement.
+ * @param int $offset Optional. The amount by which to decrement the item's value. Default 1.
+ * @param string $group Optional. The group the key is in. Default 'default'.
+ * @return false|int False on failure, the item's new value on success.
+ */
+ public function decr( $key, $offset = 1, $group = 'default' ) {
+ if ( empty( $group ) )
+ $group = 'default';
+
+ if ( $this->multisite && ! isset( $this->global_groups[ $group ] ) )
+ $key = $this->blog_prefix . $key;
+
+ if ( ! $this->_exists( $key, $group ) )
+ return false;
+
+ if ( ! is_numeric( $this->cache[ $group ][ $key ] ) )
+ $this->cache[ $group ][ $key ] = 0;
+
+ $offset = (int) $offset;
+
+ $this->cache[ $group ][ $key ] -= $offset;
+
+ if ( $this->cache[ $group ][ $key ] < 0 )
+ $this->cache[ $group ][ $key ] = 0;
+
+ return $this->cache[ $group ][ $key ];
+ }
+
+ /**
+ * Removes the contents of the cache key in the group.
+ *
+ * If the cache key does not exist in the group, then nothing will happen.