Merge branch 'wip-MDL-34343-m24' of git://github.com/samhemelryk/moodle

lib/dml/moodle_database.php

@@ -118,6 +118,9 @@ abstract class moodle_database {
     /** @var bool Flag used to force rollback of all current transactions. */
     private $force_rollback = false;
 
+    /** @var string MD5 of settings used for connection. Used by MUC as an identifier. */
+    private $settingshash;
+
     /**
      * @var int internal temporary variable used to fix params. Its used by {@link _fix_sql_params_dollar_callback()}.
      */
@@ -288,6 +291,20 @@ abstract class moodle_database {
         $this->dboptions = (array)$dboptions;
     }
 
+    /**
+     * Returns a hash for the settings used during connection.
+     *
+     * If not already requested it is generated and stored in a private property.
+     *
+     * @return string
+     */
+    protected function get_settings_hash() {
+        if (empty($this->settingshash)) {
+            $this->settingshash = md5($this->dbhost . $this->dbuser . $this->prefix);
+        }
+        return $this->settingshash;
+    }
+
     /**
      * Attempt to create the database
      * @param string $dbhost The database host.
@@ -909,6 +926,9 @@ abstract class moodle_database {
     public function reset_caches() {
         $this->columns = array();
         $this->tables  = null;
+        // Purge MUC as well
+        $identifiers = array('dbfamily' => $this->get_dbfamily(), 'settings' => $this->get_settings_hash());
+        cache_helper::purge_by_definition('core', 'databasemeta', $identifiers);
     }
 
     /**

lib/dml/mysqli_native_moodle_database.php

@@ -515,11 +515,16 @@ class mysqli_native_moodle_database extends moodle_database {
      * @return array array of database_column_info objects indexed with column names
      */
     public function get_columns($table, $usecache=true) {
-        if ($usecache and isset($this->columns[$table])) {
-            return $this->columns[$table];
+
+        if ($usecache) {
+            $properties = array('dbfamily' => $this->get_dbfamily(), 'settings' => $this->get_settings_hash());
+            $cache = cache::make('core', 'databasemeta', $properties);
+            if ($data = $cache->get($table)) {
+                return $data;
+            }
         }
 
-        $this->columns[$table] = array();
+        $structure = array();
 
         $sql = "SELECT column_name, data_type, character_maximum_length, numeric_precision,
                        numeric_scale, is_nullable, column_type, column_default, column_key, extra
@@ -539,7 +544,7 @@ class mysqli_native_moodle_database extends moodle_database {
             // standard table exists
             while ($rawcolumn = $result->fetch_assoc()) {
                 $info = (object)$this->get_column_info((object)$rawcolumn);
-                $this->columns[$table][$info->name] = new database_column_info($info);
+                $structure[$info->name] = new database_column_info($info);
             }
             $result->close();
 
@@ -614,12 +619,16 @@ class mysqli_native_moodle_database extends moodle_database {
                 }
 
                 $info = $this->get_column_info($rawcolumn);
-                $this->columns[$table][$info->name] = new database_column_info($info);
+                $structure[$info->name] = new database_column_info($info);
             }
             $result->close();
         }
 
-        return $this->columns[$table];
+        if ($usecache) {
+            $result = $cache->set($table, $structure);
+        }
+
+        return $structure;
     }
 
     /**

lib/dml/pgsql_native_moodle_database.php

@@ -395,11 +395,15 @@ class pgsql_native_moodle_database extends moodle_database {
      * @return array array of database_column_info objects indexed with column names
      */
     public function get_columns($table, $usecache=true) {
-        if ($usecache and isset($this->columns[$table])) {
-            return $this->columns[$table];
+        if ($usecache) {
+            $properties = array('dbfamily' => $this->get_dbfamily(), 'settings' => $this->get_settings_hash());
+            $cache = cache::make('core', 'databasemeta', $properties);
+            if ($data = $cache->get($table)) {
+                return $data;
+            }
         }
 
-        $this->columns[$table] = array();
+        $structure = array();
 
         $tablename = $this->prefix.$table;
 
@@ -569,12 +573,16 @@ class pgsql_native_moodle_database extends moodle_database {
 
             }
 
-            $this->columns[$table][$info->name] = new database_column_info($info);
+            $structure[$info->name] = new database_column_info($info);
         }
 
         pg_free_result($result);
 
-        return $this->columns[$table];
+        if ($usecache) {
+            $result = $cache->set($table, $structure);
+        }
+
+        return $structure;
     }
 
     /**