[DDC-692] Add ClassMetadataInfo::isReadOnly flag and ignore these entities in Change Tracking.

lib/Doctrine/ORM/Mapping/ClassMetadata.php

@@ -334,6 +334,10 @@ class ClassMetadata extends ClassMetadataInfo
             $serialized[] = 'namedQueries';
         }
 
+        if ($this->isReadOnly) {
+            $serialized[] = 'isReadOnly';
+        }
+
         return $serialized;
     }
 

lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php

@@ -484,6 +484,17 @@ class ClassMetadataInfo implements ClassMetadata
      */
     public $reflClass;
 
+    /**
+     * Is this entity marked as "read-only"?
+     *
+     * That means it is never considered for change-tracking in the UnitOfWork. It is a very helpful performance
+     * optimization for entities that are immutable, either in your domain or through the relation database
+     * (coming from a view, or a history table for example).
+     *
+     * @var bool
+     */
+    public $isReadOnly = false;
+
     /**
      * Initializes a new ClassMetadata instance that will hold the object-relational mapping
      * metadata of the class with the given name.
@@ -1818,4 +1829,14 @@ class ClassMetadataInfo implements ClassMetadata
     {
         $this->versionField = $versionField;
     }
+
+    /**
+     * Mark this class as read only, no change tracking is applied to it.
+     *
+     * @return void
+     */
+    public function markReadOnly()
+    {
+        $this->isReadOnly = true;
+    }
 }

lib/Doctrine/ORM/UnitOfWork.php

@@ -514,9 +514,9 @@ class UnitOfWork implements PropertyChangedListener
             $class = $this->em->getClassMetadata($className);
 
             // Skip class if instances are read-only
-            //if ($class->isReadOnly) {
+            if ($class->isReadOnly) {
-            //    continue;
+                continue;
-            //}
+            }
 
             // If change tracking is explicit or happens through notification, then only compute
             // changes on entities of that type that are explicitly marked for synchronization.

tests/Doctrine/Tests/ORM/Mapping/ClassMetadataTest.php

@@ -30,6 +30,8 @@ class ClassMetadataTest extends \Doctrine\Tests\OrmTestCase
         $cm->setCustomRepositoryClass("UserRepository");
         $cm->setDiscriminatorColumn(array('name' => 'disc', 'type' => 'integer'));
         $cm->mapOneToOne(array('fieldName' => 'phonenumbers', 'targetEntity' => 'Bar', 'mappedBy' => 'foo'));
+        $cm->markReadOnly();
+        $cm->addNamedQuery(array('name' => 'dql', 'query' => 'foo'));
         $this->assertEquals(1, count($cm->associationMappings));
 
         $serialized = serialize($cm);
@@ -51,6 +53,8 @@ class ClassMetadataTest extends \Doctrine\Tests\OrmTestCase
         $this->assertTrue($oneOneMapping['fetch'] == ClassMetadata::FETCH_LAZY);
         $this->assertEquals('phonenumbers', $oneOneMapping['fieldName']);
         $this->assertEquals('Doctrine\Tests\Models\CMS\Bar', $oneOneMapping['targetEntity']);
+        $this->assertTrue($cm->isReadOnly);
+        $this->assertEquals(array('dql' => 'foo'), $cm->namedQueries);
     }
 
     public function testFieldIsNullable()