vendor/doctrine/lib/Doctrine/ORM/UnitOfWork.php
changeset 0 7f95f8617b0b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/doctrine/lib/Doctrine/ORM/UnitOfWork.php	Sat Sep 24 15:40:41 2011 +0200
@@ -0,0 +1,2385 @@
+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the LGPL. For more information, see
+ * <http://www.doctrine-project.org>.
+ */
+
+namespace Doctrine\ORM;
+
+use Exception, InvalidArgumentException, UnexpectedValueException,
+    Doctrine\Common\Collections\ArrayCollection,
+    Doctrine\Common\Collections\Collection,
+    Doctrine\Common\NotifyPropertyChanged,
+    Doctrine\Common\PropertyChangedListener,
+    Doctrine\ORM\Event\LifecycleEventArgs,
+    Doctrine\ORM\Mapping\ClassMetadata,
+    Doctrine\ORM\Proxy\Proxy;
+
+/**
+ * The UnitOfWork is responsible for tracking changes to objects during an
+ * "object-level" transaction and for writing out changes to the database
+ * in the correct order.
+ *
+ * @since       2.0
+ * @author      Benjamin Eberlei <kontakt@beberlei.de>
+ * @author      Guilherme Blanco <guilhermeblanco@hotmail.com>
+ * @author      Jonathan Wage <jonwage@gmail.com>
+ * @author      Roman Borschel <roman@code-factory.org>
+ * @internal    This class contains highly performance-sensitive code.
+ */
+class UnitOfWork implements PropertyChangedListener
+{
+    /**
+     * An entity is in MANAGED state when its persistence is managed by an EntityManager.
+     */
+    const STATE_MANAGED = 1;
+
+    /**
+     * An entity is new if it has just been instantiated (i.e. using the "new" operator)
+     * and is not (yet) managed by an EntityManager.
+     */
+    const STATE_NEW = 2;
+
+    /**
+     * A detached entity is an instance with persistent state and identity that is not
+     * (or no longer) associated with an EntityManager (and a UnitOfWork).
+     */
+    const STATE_DETACHED = 3;
+
+    /**
+     * A removed entity instance is an instance with a persistent identity,
+     * associated with an EntityManager, whose persistent state will be deleted
+     * on commit.
+     */
+    const STATE_REMOVED = 4;
+
+    /**
+     * The identity map that holds references to all managed entities that have
+     * an identity. The entities are grouped by their class name.
+     * Since all classes in a hierarchy must share the same identifier set,
+     * we always take the root class name of the hierarchy.
+     *
+     * @var array
+     */
+    private $identityMap = array();
+
+    /**
+     * Map of all identifiers of managed entities.
+     * Keys are object ids (spl_object_hash).
+     *
+     * @var array
+     */
+    private $entityIdentifiers = array();
+
+    /**
+     * Map of the original entity data of managed entities.
+     * Keys are object ids (spl_object_hash). This is used for calculating changesets
+     * at commit time.
+     *
+     * @var array
+     * @internal Note that PHPs "copy-on-write" behavior helps a lot with memory usage.
+     *           A value will only really be copied if the value in the entity is modified
+     *           by the user.
+     */
+    private $originalEntityData = array();
+
+    /**
+     * Map of entity changes. Keys are object ids (spl_object_hash).
+     * Filled at the beginning of a commit of the UnitOfWork and cleaned at the end.
+     *
+     * @var array
+     */
+    private $entityChangeSets = array();
+
+    /**
+     * The (cached) states of any known entities.
+     * Keys are object ids (spl_object_hash).
+     *
+     * @var array
+     */
+    private $entityStates = array();
+
+    /**
+     * Map of entities that are scheduled for dirty checking at commit time.
+     * This is only used for entities with a change tracking policy of DEFERRED_EXPLICIT.
+     * Keys are object ids (spl_object_hash).
+     * 
+     * @var array
+     * @todo rename: scheduledForSynchronization
+     */
+    private $scheduledForDirtyCheck = array();
+
+    /**
+     * A list of all pending entity insertions.
+     *
+     * @var array
+     */
+    private $entityInsertions = array();
+
+    /**
+     * A list of all pending entity updates.
+     *
+     * @var array
+     */
+    private $entityUpdates = array();
+    
+    /**
+     * Any pending extra updates that have been scheduled by persisters.
+     * 
+     * @var array
+     */
+    private $extraUpdates = array();
+
+    /**
+     * A list of all pending entity deletions.
+     *
+     * @var array
+     */
+    private $entityDeletions = array();
+
+    /**
+     * All pending collection deletions.
+     *
+     * @var array
+     */
+    private $collectionDeletions = array();
+
+    /**
+     * All pending collection updates.
+     *
+     * @var array
+     */
+    private $collectionUpdates = array();
+
+    /**
+     * List of collections visited during changeset calculation on a commit-phase of a UnitOfWork.
+     * At the end of the UnitOfWork all these collections will make new snapshots
+     * of their data.
+     *
+     * @var array
+     */
+    private $visitedCollections = array();
+
+    /**
+     * The EntityManager that "owns" this UnitOfWork instance.
+     *
+     * @var Doctrine\ORM\EntityManager
+     */
+    private $em;
+
+    /**
+     * The calculator used to calculate the order in which changes to
+     * entities need to be written to the database.
+     *
+     * @var Doctrine\ORM\Internal\CommitOrderCalculator
+     */
+    private $commitOrderCalculator;
+
+    /**
+     * The entity persister instances used to persist entity instances.
+     *
+     * @var array
+     */
+    private $persisters = array();
+
+    /**
+     * The collection persister instances used to persist collections.
+     *
+     * @var array
+     */
+    private $collectionPersisters = array();
+    
+    /**
+     * The EventManager used for dispatching events.
+     * 
+     * @var EventManager
+     */
+    private $evm;
+    
+    /**
+     * Orphaned entities that are scheduled for removal.
+     * 
+     * @var array
+     */
+    private $orphanRemovals = array();
+    
+    //private $_readOnlyObjects = array();
+
+    /**
+     * Map of Entity Class-Names and corresponding IDs that should eager loaded when requested.
+     * 
+     * @var array
+     */
+    private $eagerLoadingEntities = array();
+
+    /**
+     * Initializes a new UnitOfWork instance, bound to the given EntityManager.
+     *
+     * @param Doctrine\ORM\EntityManager $em
+     */
+    public function __construct(EntityManager $em)
+    {
+        $this->em = $em;
+        $this->evm = $em->getEventManager();
+    }
+
+    /**
+     * Commits the UnitOfWork, executing all operations that have been postponed
+     * up to this point. The state of all managed entities will be synchronized with
+     * the database.
+     * 
+     * The operations are executed in the following order:
+     * 
+     * 1) All entity insertions
+     * 2) All entity updates
+     * 3) All collection deletions
+     * 4) All collection updates
+     * 5) All entity deletions
+     * 
+     */
+    public function commit()
+    {
+        // Compute changes done since last commit.
+        $this->computeChangeSets();
+
+        if ( ! ($this->entityInsertions ||
+                $this->entityDeletions ||
+                $this->entityUpdates ||
+                $this->collectionUpdates ||
+                $this->collectionDeletions ||
+                $this->orphanRemovals)) {
+            return; // Nothing to do.
+        }
+
+        if ($this->orphanRemovals) {
+            foreach ($this->orphanRemovals as $orphan) {
+                $this->remove($orphan);
+            }
+        }
+        
+        // Raise onFlush
+        if ($this->evm->hasListeners(Events::onFlush)) {
+            $this->evm->dispatchEvent(Events::onFlush, new Event\OnFlushEventArgs($this->em));
+        }
+        
+        // Now we need a commit order to maintain referential integrity
+        $commitOrder = $this->getCommitOrder();
+
+        $conn = $this->em->getConnection();
+
+        $conn->beginTransaction();
+        try {
+            if ($this->entityInsertions) {
+                foreach ($commitOrder as $class) {
+                    $this->executeInserts($class);
+                }
+            }
+
+            if ($this->entityUpdates) {
+                foreach ($commitOrder as $class) {
+                    $this->executeUpdates($class);
+                }
+            }
+
+            // Extra updates that were requested by persisters.
+            if ($this->extraUpdates) {
+                $this->executeExtraUpdates();
+            }
+
+            // Collection deletions (deletions of complete collections)
+            foreach ($this->collectionDeletions as $collectionToDelete) {
+                $this->getCollectionPersister($collectionToDelete->getMapping())
+                        ->delete($collectionToDelete);
+            }
+            // Collection updates (deleteRows, updateRows, insertRows)
+            foreach ($this->collectionUpdates as $collectionToUpdate) {
+                $this->getCollectionPersister($collectionToUpdate->getMapping())
+                        ->update($collectionToUpdate);
+            }
+
+            // Entity deletions come last and need to be in reverse commit order
+            if ($this->entityDeletions) {
+                for ($count = count($commitOrder), $i = $count - 1; $i >= 0; --$i) {
+                    $this->executeDeletions($commitOrder[$i]);
+                }
+            }
+
+            $conn->commit();
+        } catch (Exception $e) {
+            $this->em->close();
+            $conn->rollback();
+            throw $e;
+        }
+
+        // Take new snapshots from visited collections
+        foreach ($this->visitedCollections as $coll) {
+            $coll->takeSnapshot();
+        }
+
+        // Clear up
+        $this->entityInsertions =
+        $this->entityUpdates =
+        $this->entityDeletions =
+        $this->extraUpdates =
+        $this->entityChangeSets =
+        $this->collectionUpdates =
+        $this->collectionDeletions =
+        $this->visitedCollections =
+        $this->scheduledForDirtyCheck =
+        $this->orphanRemovals = array();
+    }
+    
+    /**
+     * Executes any extra updates that have been scheduled.
+     */
+    private function executeExtraUpdates()
+    {
+        foreach ($this->extraUpdates as $oid => $update) {
+            list ($entity, $changeset) = $update;
+            $this->entityChangeSets[$oid] = $changeset;
+            $this->getEntityPersister(get_class($entity))->update($entity);
+        }
+    }
+
+    /**
+     * Gets the changeset for an entity.
+     *
+     * @return array
+     */
+    public function getEntityChangeSet($entity)
+    {
+        $oid = spl_object_hash($entity);
+        if (isset($this->entityChangeSets[$oid])) {
+            return $this->entityChangeSets[$oid];
+        }
+        return array();
+    }
+
+    /**
+     * Computes the changes that happened to a single entity.
+     *
+     * Modifies/populates the following properties:
+     *
+     * {@link _originalEntityData}
+     * If the entity is NEW or MANAGED but not yet fully persisted (only has an id)
+     * then it was not fetched from the database and therefore we have no original
+     * entity data yet. All of the current entity data is stored as the original entity data.
+     *
+     * {@link _entityChangeSets}
+     * The changes detected on all properties of the entity are stored there.
+     * A change is a tuple array where the first entry is the old value and the second
+     * entry is the new value of the property. Changesets are used by persisters
+     * to INSERT/UPDATE the persistent entity state.
+     *
+     * {@link _entityUpdates}
+     * If the entity is already fully MANAGED (has been fetched from the database before)
+     * and any changes to its properties are detected, then a reference to the entity is stored
+     * there to mark it for an update.
+     *
+     * {@link _collectionDeletions}
+     * If a PersistentCollection has been de-referenced in a fully MANAGED entity,
+     * then this collection is marked for deletion.
+     *
+     * @param ClassMetadata $class The class descriptor of the entity.
+     * @param object $entity The entity for which to compute the changes.
+     */
+    public function computeChangeSet(ClassMetadata $class, $entity)
+    {
+        if ( ! $class->isInheritanceTypeNone()) {
+            $class = $this->em->getClassMetadata(get_class($entity));
+        }
+        
+        $oid = spl_object_hash($entity);
+        $actualData = array();
+        foreach ($class->reflFields as $name => $refProp) {
+            $value = $refProp->getValue($entity);
+            if (isset($class->associationMappings[$name])
+                    && ($class->associationMappings[$name]['type'] & ClassMetadata::TO_MANY)
+                    && $value !== null
+                    && ! ($value instanceof PersistentCollection)) {
+
+                // If $value is not a Collection then use an ArrayCollection.
+                if ( ! $value instanceof Collection) {
+                    $value = new ArrayCollection($value);
+                }
+                
+                $assoc = $class->associationMappings[$name];
+                
+                // Inject PersistentCollection
+                $coll = new PersistentCollection(
+                    $this->em,
+                    $this->em->getClassMetadata($assoc['targetEntity']),
+                    $value
+                );
+                
+                $coll->setOwner($entity, $assoc);
+                $coll->setDirty( ! $coll->isEmpty());
+                $class->reflFields[$name]->setValue($entity, $coll);
+                $actualData[$name] = $coll;
+            } else if ( (! $class->isIdentifier($name) || ! $class->isIdGeneratorIdentity()) && ($name !== $class->versionField) ) {
+                $actualData[$name] = $value;
+            }
+        }
+
+        if ( ! isset($this->originalEntityData[$oid])) {
+            // Entity is either NEW or MANAGED but not yet fully persisted (only has an id).
+            // These result in an INSERT.
+            $this->originalEntityData[$oid] = $actualData;
+            $changeSet = array();
+            foreach ($actualData as $propName => $actualValue) {
+                if (isset($class->associationMappings[$propName])) {
+                    $assoc = $class->associationMappings[$propName];
+                    if ($assoc['isOwningSide'] && $assoc['type'] & ClassMetadata::TO_ONE) {
+                        $changeSet[$propName] = array(null, $actualValue);
+                    }
+                } else {
+                    $changeSet[$propName] = array(null, $actualValue);
+                }
+            }
+            $this->entityChangeSets[$oid] = $changeSet;
+        } else {
+            // Entity is "fully" MANAGED: it was already fully persisted before
+            // and we have a copy of the original data
+            $originalData = $this->originalEntityData[$oid];
+            $isChangeTrackingNotify = $class->isChangeTrackingNotify();
+            $changeSet = ($isChangeTrackingNotify && isset($this->entityChangeSets[$oid])) ? $this->entityChangeSets[$oid] : array();
+
+            foreach ($actualData as $propName => $actualValue) {
+                $orgValue = isset($originalData[$propName]) ? $originalData[$propName] : null;
+                if (isset($class->associationMappings[$propName])) {
+                    $assoc = $class->associationMappings[$propName];
+                    if ($assoc['type'] & ClassMetadata::TO_ONE && $orgValue !== $actualValue) {
+                        if ($assoc['isOwningSide']) {
+                            $changeSet[$propName] = array($orgValue, $actualValue);
+                        }
+                        if ($orgValue !== null && $assoc['orphanRemoval']) {
+                            $this->scheduleOrphanRemoval($orgValue);
+                        }
+                    } else if ($orgValue instanceof PersistentCollection && $orgValue !== $actualValue) {
+                        // A PersistentCollection was de-referenced, so delete it.
+                        if  ( ! in_array($orgValue, $this->collectionDeletions, true)) {
+                            $this->collectionDeletions[] = $orgValue;
+                            $changeSet[$propName] = $orgValue; // Signal changeset, to-many assocs will be ignored.
+                        }
+                    }
+                } else if ($isChangeTrackingNotify) {
+                    continue;
+                } else if ($orgValue !== $actualValue) {
+                    $changeSet[$propName] = array($orgValue, $actualValue);
+                }
+            }
+            if ($changeSet) {
+                $this->entityChangeSets[$oid] = $changeSet;
+                $this->originalEntityData[$oid] = $actualData;
+                $this->entityUpdates[$oid] = $entity;
+            }
+        }
+
+        // Look for changes in associations of the entity
+        foreach ($class->associationMappings as $field => $assoc) {
+            $val = $class->reflFields[$field]->getValue($entity);
+            if ($val !== null) {
+                $this->computeAssociationChanges($assoc, $val);
+            }
+        }
+    }
+
+    /**
+     * Computes all the changes that have been done to entities and collections
+     * since the last commit and stores these changes in the _entityChangeSet map
+     * temporarily for access by the persisters, until the UoW commit is finished.
+     */
+    public function computeChangeSets()
+    {
+        // Compute changes for INSERTed entities first. This must always happen.
+        foreach ($this->entityInsertions as $entity) {
+            $class = $this->em->getClassMetadata(get_class($entity));
+            $this->computeChangeSet($class, $entity);
+        }
+
+        // Compute changes for other MANAGED entities. Change tracking policies take effect here.
+        foreach ($this->identityMap as $className => $entities) {
+            $class = $this->em->getClassMetadata($className);
+
+            // Skip class if instances are read-only
+            if ($class->isReadOnly) {
+                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.
+            $entitiesToProcess = ! $class->isChangeTrackingDeferredImplicit() ?
+                    (isset($this->scheduledForDirtyCheck[$className]) ?
+                        $this->scheduledForDirtyCheck[$className] : array())
+                    : $entities;
+
+            foreach ($entitiesToProcess as $entity) {
+                // Ignore uninitialized proxy objects
+                if (/* $entity is readOnly || */ $entity instanceof Proxy && ! $entity->__isInitialized__) {
+                    continue;
+                }
+                // Only MANAGED entities that are NOT SCHEDULED FOR INSERTION are processed here.
+                $oid = spl_object_hash($entity);
+                if ( ! isset($this->entityInsertions[$oid]) && isset($this->entityStates[$oid])) {
+                    $this->computeChangeSet($class, $entity);
+                }
+            }
+        }
+    }
+
+    /**
+     * Computes the changes of an association.
+     *
+     * @param AssociationMapping $assoc
+     * @param mixed $value The value of the association.
+     */
+    private function computeAssociationChanges($assoc, $value)
+    {
+        if ($value instanceof PersistentCollection && $value->isDirty()) {
+            if ($assoc['isOwningSide']) {
+                $this->collectionUpdates[] = $value;
+            }
+            $this->visitedCollections[] = $value;
+        }
+
+        // Look through the entities, and in any of their associations, for transient (new)
+        // enities, recursively. ("Persistence by reachability")
+        if ($assoc['type'] & ClassMetadata::TO_ONE) {
+            if ($value instanceof Proxy && ! $value->__isInitialized__) {
+                return; // Ignore uninitialized proxy objects
+            }
+            $value = array($value);
+        } else if ($value instanceof PersistentCollection) {
+            // Unwrap. Uninitialized collections will simply be empty.
+            $value = $value->unwrap();
+        }
+
+        $targetClass = $this->em->getClassMetadata($assoc['targetEntity']);
+        foreach ($value as $entry) {
+            $state = $this->getEntityState($entry, self::STATE_NEW);
+            $oid = spl_object_hash($entry);
+            if ($state == self::STATE_NEW) {
+                if ( ! $assoc['isCascadePersist']) {
+                    throw new InvalidArgumentException("A new entity was found through the relationship '"
+                            . $assoc['sourceEntity'] . "#" . $assoc['fieldName'] . "' that was not"
+                            . " configured to cascade persist operations for entity: " . self::objToStr($entry) . "."
+                            . " Explicitly persist the new entity or configure cascading persist operations"
+                            . " on the relationship. If you cannot find out which entity causes the problem"
+                            . " implement '" . $assoc['targetEntity'] . "#__toString()' to get a clue.");
+                }
+                $this->persistNew($targetClass, $entry);
+                $this->computeChangeSet($targetClass, $entry);
+            } else if ($state == self::STATE_REMOVED) {
+                return new InvalidArgumentException("Removed entity detected during flush: "
+                        . self::objToStr($entry).". Remove deleted entities from associations.");
+            } else if ($state == self::STATE_DETACHED) {
+                // Can actually not happen right now as we assume STATE_NEW,
+                // so the exception will be raised from the DBAL layer (constraint violation).
+                throw new InvalidArgumentException("A detached entity was found through a "
+                        . "relationship during cascading a persist operation.");
+            }
+            // MANAGED associated entities are already taken into account
+            // during changeset calculation anyway, since they are in the identity map.
+        }
+    }
+
+    private function persistNew($class, $entity)
+    {
+        $oid = spl_object_hash($entity);
+        if (isset($class->lifecycleCallbacks[Events::prePersist])) {
+            $class->invokeLifecycleCallbacks(Events::prePersist, $entity);
+        }
+        if ($this->evm->hasListeners(Events::prePersist)) {
+            $this->evm->dispatchEvent(Events::prePersist, new LifecycleEventArgs($entity, $this->em));
+        }
+
+        $idGen = $class->idGenerator;
+        if ( ! $idGen->isPostInsertGenerator()) {
+            $idValue = $idGen->generate($this->em, $entity);
+            if ( ! $idGen instanceof \Doctrine\ORM\Id\AssignedGenerator) {
+                $this->entityIdentifiers[$oid] = array($class->identifier[0] => $idValue);
+                $class->setIdentifierValues($entity, $this->entityIdentifiers[$oid]);
+            } else {
+                $this->entityIdentifiers[$oid] = $idValue;
+            }
+        }
+        $this->entityStates[$oid] = self::STATE_MANAGED;
+
+        $this->scheduleForInsert($entity);
+    }
+    
+    /**
+     * INTERNAL:
+     * Computes the changeset of an individual entity, independently of the
+     * computeChangeSets() routine that is used at the beginning of a UnitOfWork#commit().
+     * 
+     * The passed entity must be a managed entity. If the entity already has a change set
+     * because this method is invoked during a commit cycle then the change sets are added.
+     * whereby changes detected in this method prevail.
+     * 
+     * @ignore
+     * @param ClassMetadata $class The class descriptor of the entity.
+     * @param object $entity The entity for which to (re)calculate the change set.
+     * @throws InvalidArgumentException If the passed entity is not MANAGED.
+     */
+    public function recomputeSingleEntityChangeSet($class, $entity)
+    {
+        $oid = spl_object_hash($entity);
+        
+        if ( ! isset($this->entityStates[$oid]) || $this->entityStates[$oid] != self::STATE_MANAGED) {
+            throw new InvalidArgumentException('Entity must be managed.');
+        }
+        
+        /* TODO: Just return if changetracking policy is NOTIFY?
+        if ($class->isChangeTrackingNotify()) {
+            return;
+        }*/
+
+        if ( ! $class->isInheritanceTypeNone()) {
+            $class = $this->em->getClassMetadata(get_class($entity));
+        }
+
+        $actualData = array();
+        foreach ($class->reflFields as $name => $refProp) {
+            if ( ! $class->isIdentifier($name) || ! $class->isIdGeneratorIdentity()) {
+                $actualData[$name] = $refProp->getValue($entity);
+            }
+        }
+
+        $originalData = $this->originalEntityData[$oid];
+        $changeSet = array();
+
+        foreach ($actualData as $propName => $actualValue) {
+            $orgValue = isset($originalData[$propName]) ? $originalData[$propName] : null;
+            if (is_object($orgValue) && $orgValue !== $actualValue) {
+                $changeSet[$propName] = array($orgValue, $actualValue);
+            } else if ($orgValue != $actualValue || ($orgValue === null ^ $actualValue === null)) {
+                $changeSet[$propName] = array($orgValue, $actualValue);
+            }
+        }
+
+        if ($changeSet) {
+            if (isset($this->entityChangeSets[$oid])) {
+                $this->entityChangeSets[$oid] = array_merge($this->entityChangeSets[$oid], $changeSet);
+            }
+            $this->originalEntityData[$oid] = $actualData;
+        }
+    }
+
+    /**
+     * Executes all entity insertions for entities of the specified type.
+     *
+     * @param Doctrine\ORM\Mapping\ClassMetadata $class
+     */
+    private function executeInserts($class)
+    {
+        $className = $class->name;
+        $persister = $this->getEntityPersister($className);
+        
+        $hasLifecycleCallbacks = isset($class->lifecycleCallbacks[Events::postPersist]);
+        $hasListeners = $this->evm->hasListeners(Events::postPersist);
+        if ($hasLifecycleCallbacks || $hasListeners) {
+            $entities = array();
+        }
+        
+        foreach ($this->entityInsertions as $oid => $entity) {
+            if (get_class($entity) === $className) {
+                $persister->addInsert($entity);
+                unset($this->entityInsertions[$oid]);
+                if ($hasLifecycleCallbacks || $hasListeners) {
+                    $entities[] = $entity;
+                }
+            }
+        }
+
+        $postInsertIds = $persister->executeInserts();
+
+        if ($postInsertIds) {
+            // Persister returned post-insert IDs
+            foreach ($postInsertIds as $id => $entity) {
+                $oid = spl_object_hash($entity);
+                $idField = $class->identifier[0];
+                $class->reflFields[$idField]->setValue($entity, $id);
+                $this->entityIdentifiers[$oid] = array($idField => $id);
+                $this->entityStates[$oid] = self::STATE_MANAGED;
+                $this->originalEntityData[$oid][$idField] = $id;
+                $this->addToIdentityMap($entity);
+            }
+        }
+        
+        if ($hasLifecycleCallbacks || $hasListeners) {
+            foreach ($entities as $entity) {
+                if ($hasLifecycleCallbacks) {
+                    $class->invokeLifecycleCallbacks(Events::postPersist, $entity);
+                }
+                if ($hasListeners) {
+                    $this->evm->dispatchEvent(Events::postPersist, new LifecycleEventArgs($entity, $this->em));
+                }
+            }
+        }
+    }
+
+    /**
+     * Executes all entity updates for entities of the specified type.
+     *
+     * @param Doctrine\ORM\Mapping\ClassMetadata $class
+     */
+    private function executeUpdates($class)
+    {
+        $className = $class->name;
+        $persister = $this->getEntityPersister($className);
+
+        $hasPreUpdateLifecycleCallbacks = isset($class->lifecycleCallbacks[Events::preUpdate]);
+        $hasPreUpdateListeners = $this->evm->hasListeners(Events::preUpdate);
+        $hasPostUpdateLifecycleCallbacks = isset($class->lifecycleCallbacks[Events::postUpdate]);
+        $hasPostUpdateListeners = $this->evm->hasListeners(Events::postUpdate);
+        
+        foreach ($this->entityUpdates as $oid => $entity) {
+            if (get_class($entity) == $className || $entity instanceof Proxy && get_parent_class($entity) == $className) {
+                
+                if ($hasPreUpdateLifecycleCallbacks) {
+                    $class->invokeLifecycleCallbacks(Events::preUpdate, $entity);
+                    $this->recomputeSingleEntityChangeSet($class, $entity);
+                }
+                
+                if ($hasPreUpdateListeners) {
+                    $this->evm->dispatchEvent(Events::preUpdate, new Event\PreUpdateEventArgs(
+                        $entity, $this->em, $this->entityChangeSets[$oid])
+                    );
+                }
+
+                if ($this->entityChangeSets[$oid]) {
+                    $persister->update($entity);
+                }
+                unset($this->entityUpdates[$oid]);
+                
+                if ($hasPostUpdateLifecycleCallbacks) {
+                    $class->invokeLifecycleCallbacks(Events::postUpdate, $entity);
+                }
+                if ($hasPostUpdateListeners) {
+                    $this->evm->dispatchEvent(Events::postUpdate, new LifecycleEventArgs($entity, $this->em));
+                }
+            }
+        }
+    }
+
+    /**
+     * Executes all entity deletions for entities of the specified type.
+     *
+     * @param Doctrine\ORM\Mapping\ClassMetadata $class
+     */
+    private function executeDeletions($class)
+    {
+        $className = $class->name;
+        $persister = $this->getEntityPersister($className);
+                
+        $hasLifecycleCallbacks = isset($class->lifecycleCallbacks[Events::postRemove]);
+        $hasListeners = $this->evm->hasListeners(Events::postRemove);
+        
+        foreach ($this->entityDeletions as $oid => $entity) {
+            if (get_class($entity) == $className || $entity instanceof Proxy && get_parent_class($entity) == $className) {
+                $persister->delete($entity);
+                unset(
+                    $this->entityDeletions[$oid],
+                    $this->entityIdentifiers[$oid],
+                    $this->originalEntityData[$oid],
+                    $this->entityStates[$oid]
+                    );
+                // Entity with this $oid after deletion treated as NEW, even if the $oid
+                // is obtained by a new entity because the old one went out of scope.
+                //$this->entityStates[$oid] = self::STATE_NEW;
+                if ( ! $class->isIdentifierNatural()) {
+                    $class->reflFields[$class->identifier[0]]->setValue($entity, null);
+                }
+
+                if ($hasLifecycleCallbacks) {
+                    $class->invokeLifecycleCallbacks(Events::postRemove, $entity);
+                }
+                if ($hasListeners) {
+                    $this->evm->dispatchEvent(Events::postRemove, new LifecycleEventArgs($entity, $this->em));
+                }
+            }
+        }
+    }
+
+    /**
+     * Gets the commit order.
+     *
+     * @return array
+     */
+    private function getCommitOrder(array $entityChangeSet = null)
+    {
+        if ($entityChangeSet === null) {
+            $entityChangeSet = array_merge(
+                    $this->entityInsertions,
+                    $this->entityUpdates,
+                    $this->entityDeletions
+                    );
+        }
+        
+        $calc = $this->getCommitOrderCalculator();
+        
+        // See if there are any new classes in the changeset, that are not in the
+        // commit order graph yet (dont have a node).
+        $newNodes = array();
+        foreach ($entityChangeSet as $oid => $entity) {
+            $className = get_class($entity);         
+            if ( ! $calc->hasClass($className)) {
+                $class = $this->em->getClassMetadata($className);
+                $calc->addClass($class);
+                $newNodes[] = $class;
+            }
+        }
+
+        // Calculate dependencies for new nodes
+        foreach ($newNodes as $class) {
+            foreach ($class->associationMappings as $assoc) {
+                if ($assoc['isOwningSide'] && $assoc['type'] & ClassMetadata::TO_ONE) {
+                    $targetClass = $this->em->getClassMetadata($assoc['targetEntity']);
+                    if ( ! $calc->hasClass($targetClass->name)) {
+                        $calc->addClass($targetClass);
+                    }
+                    $calc->addDependency($targetClass, $class);
+                    // If the target class has mapped subclasses,
+                    // these share the same dependency.
+                    if ($targetClass->subClasses) {
+                        foreach ($targetClass->subClasses as $subClassName) {
+                            $targetSubClass = $this->em->getClassMetadata($subClassName);
+                            if ( ! $calc->hasClass($subClassName)) {
+                                $calc->addClass($targetSubClass);
+                            }
+                            $calc->addDependency($targetSubClass, $class);
+                        }
+                    }
+                }
+            }
+        }
+
+        return $calc->getCommitOrder();
+    }
+
+    /**
+     * Schedules an entity for insertion into the database.
+     * If the entity already has an identifier, it will be added to the identity map.
+     *
+     * @param object $entity The entity to schedule for insertion.
+     */
+    public function scheduleForInsert($entity)
+    {
+        $oid = spl_object_hash($entity);
+
+        if (isset($this->entityUpdates[$oid])) {
+            throw new InvalidArgumentException("Dirty entity can not be scheduled for insertion.");
+        }
+        if (isset($this->entityDeletions[$oid])) {
+            throw new InvalidArgumentException("Removed entity can not be scheduled for insertion.");
+        }
+        if (isset($this->entityInsertions[$oid])) {
+            throw new InvalidArgumentException("Entity can not be scheduled for insertion twice.");
+        }
+
+        $this->entityInsertions[$oid] = $entity;
+
+        if (isset($this->entityIdentifiers[$oid])) {
+            $this->addToIdentityMap($entity);
+        }
+    }
+
+    /**
+     * Checks whether an entity is scheduled for insertion.
+     *
+     * @param object $entity
+     * @return boolean
+     */
+    public function isScheduledForInsert($entity)
+    {
+        return isset($this->entityInsertions[spl_object_hash($entity)]);
+    }
+
+    /**
+     * Schedules an entity for being updated.
+     *
+     * @param object $entity The entity to schedule for being updated.
+     */
+    public function scheduleForUpdate($entity)
+    {
+        $oid = spl_object_hash($entity);
+        if ( ! isset($this->entityIdentifiers[$oid])) {
+            throw new InvalidArgumentException("Entity has no identity.");
+        }
+        if (isset($this->entityDeletions[$oid])) {
+            throw new InvalidArgumentException("Entity is removed.");
+        }
+
+        if ( ! isset($this->entityUpdates[$oid]) && ! isset($this->entityInsertions[$oid])) {
+            $this->entityUpdates[$oid] = $entity;
+        }
+    }
+    
+    /**
+     * INTERNAL:
+     * Schedules an extra update that will be executed immediately after the
+     * regular entity updates within the currently running commit cycle.
+     * 
+     * Extra updates for entities are stored as (entity, changeset) tuples.
+     * 
+     * @ignore
+     * @param object $entity The entity for which to schedule an extra update.
+     * @param array $changeset The changeset of the entity (what to update).
+     */
+    public function scheduleExtraUpdate($entity, array $changeset)
+    {
+        $oid = spl_object_hash($entity);
+        if (isset($this->extraUpdates[$oid])) {
+            list($ignored, $changeset2) = $this->extraUpdates[$oid];
+            $this->extraUpdates[$oid] = array($entity, $changeset + $changeset2);
+        } else {
+            $this->extraUpdates[$oid] = array($entity, $changeset);
+        }
+    }
+
+    /**
+     * Checks whether an entity is registered as dirty in the unit of work.
+     * Note: Is not very useful currently as dirty entities are only registered
+     * at commit time.
+     *
+     * @param object $entity
+     * @return boolean
+     */
+    public function isScheduledForUpdate($entity)
+    {
+        return isset($this->entityUpdates[spl_object_hash($entity)]);
+    }
+
+    public function isScheduledForDirtyCheck($entity)
+    {
+        $rootEntityName = $this->em->getClassMetadata(get_class($entity))->rootEntityName;
+        return isset($this->scheduledForDirtyCheck[$rootEntityName][spl_object_hash($entity)]);
+    }
+
+    /**
+     * INTERNAL:
+     * Schedules an entity for deletion.
+     * 
+     * @param object $entity
+     */
+    public function scheduleForDelete($entity)
+    {
+        $oid = spl_object_hash($entity);
+        
+        if (isset($this->entityInsertions[$oid])) {
+            if ($this->isInIdentityMap($entity)) {
+                $this->removeFromIdentityMap($entity);
+            }
+            unset($this->entityInsertions[$oid], $this->entityStates[$oid]);
+            return; // entity has not been persisted yet, so nothing more to do.
+        }
+
+        if ( ! $this->isInIdentityMap($entity)) {
+            return; // ignore
+        }
+
+        $this->removeFromIdentityMap($entity);
+
+        if (isset($this->entityUpdates[$oid])) {
+            unset($this->entityUpdates[$oid]);
+        }
+        if ( ! isset($this->entityDeletions[$oid])) {
+            $this->entityDeletions[$oid] = $entity;
+            $this->entityStates[$oid] = self::STATE_REMOVED;
+        }
+    }
+
+    /**
+     * Checks whether an entity is registered as removed/deleted with the unit
+     * of work.
+     *
+     * @param object $entity
+     * @return boolean
+     */
+    public function isScheduledForDelete($entity)
+    {
+        return isset($this->entityDeletions[spl_object_hash($entity)]);
+    }
+
+    /**
+     * Checks whether an entity is scheduled for insertion, update or deletion.
+     * 
+     * @param $entity
+     * @return boolean
+     */
+    public function isEntityScheduled($entity)
+    {
+        $oid = spl_object_hash($entity);
+        return isset($this->entityInsertions[$oid]) ||
+                isset($this->entityUpdates[$oid]) ||
+                isset($this->entityDeletions[$oid]);
+    }
+
+    /**
+     * INTERNAL:
+     * Registers an entity in the identity map.
+     * Note that entities in a hierarchy are registered with the class name of
+     * the root entity.
+     *
+     * @ignore
+     * @param object $entity  The entity to register.
+     * @return boolean  TRUE if the registration was successful, FALSE if the identity of
+     *                  the entity in question is already managed.
+     */
+    public function addToIdentityMap($entity)
+    {
+        $classMetadata = $this->em->getClassMetadata(get_class($entity));
+        $idHash = implode(' ', $this->entityIdentifiers[spl_object_hash($entity)]);
+        if ($idHash === '') {
+            throw new InvalidArgumentException("The given entity has no identity.");
+        }
+        $className = $classMetadata->rootEntityName;
+        if (isset($this->identityMap[$className][$idHash])) {
+            return false;
+        }
+        $this->identityMap[$className][$idHash] = $entity;
+        if ($entity instanceof NotifyPropertyChanged) {
+            $entity->addPropertyChangedListener($this);
+        }
+        return true;
+    }
+
+    /**
+     * Gets the state of an entity with regard to the current unit of work.
+     *
+     * @param object $entity
+     * @param integer $assume The state to assume if the state is not yet known (not MANAGED or REMOVED).
+     *                        This parameter can be set to improve performance of entity state detection
+     *                        by potentially avoiding a database lookup if the distinction between NEW and DETACHED
+     *                        is either known or does not matter for the caller of the method.
+     * @return int The entity state.
+     */
+    public function getEntityState($entity, $assume = null)
+    {
+        $oid = spl_object_hash($entity);
+        if ( ! isset($this->entityStates[$oid])) {
+            // State can only be NEW or DETACHED, because MANAGED/REMOVED states are known.
+            // Note that you can not remember the NEW or DETACHED state in _entityStates since
+            // the UoW does not hold references to such objects and the object hash can be reused.
+            // More generally because the state may "change" between NEW/DETACHED without the UoW being aware of it.
+            if ($assume === null) {
+                $class = $this->em->getClassMetadata(get_class($entity));
+                $id = $class->getIdentifierValues($entity);
+                if ( ! $id) {
+                    return self::STATE_NEW;
+                } else if ($class->isIdentifierNatural()) {
+                    // Check for a version field, if available, to avoid a db lookup.
+                    if ($class->isVersioned) {
+                        if ($class->getFieldValue($entity, $class->versionField)) {
+                            return self::STATE_DETACHED;
+                        } else {
+                            return self::STATE_NEW;
+                        }
+                    } else {
+                        // Last try before db lookup: check the identity map.
+                        if ($this->tryGetById($id, $class->rootEntityName)) {
+                            return self::STATE_DETACHED;
+                        } else {
+                            // db lookup
+                            if ($this->getEntityPersister(get_class($entity))->exists($entity)) {
+                                return self::STATE_DETACHED;
+                            } else {
+                                return self::STATE_NEW;
+                            }
+                        }
+                    }
+                } else {
+                    return self::STATE_DETACHED;
+                }
+            } else {
+                return $assume;
+            }
+        }
+        return $this->entityStates[$oid];
+    }
+
+    /**
+     * INTERNAL:
+     * Removes an entity from the identity map. This effectively detaches the
+     * entity from the persistence management of Doctrine.
+     *
+     * @ignore
+     * @param object $entity
+     * @return boolean
+     */
+    public function removeFromIdentityMap($entity)
+    {
+        $oid = spl_object_hash($entity);
+        $classMetadata = $this->em->getClassMetadata(get_class($entity));
+        $idHash = implode(' ', $this->entityIdentifiers[$oid]);
+        if ($idHash === '') {
+            throw new InvalidArgumentException("The given entity has no identity.");
+        }
+        $className = $classMetadata->rootEntityName;
+        if (isset($this->identityMap[$className][$idHash])) {
+            unset($this->identityMap[$className][$idHash]);
+            //$this->entityStates[$oid] = self::STATE_DETACHED;
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * INTERNAL:
+     * Gets an entity in the identity map by its identifier hash.
+     *
+     * @ignore
+     * @param string $idHash
+     * @param string $rootClassName
+     * @return object
+     */
+    public function getByIdHash($idHash, $rootClassName)
+    {
+        return $this->identityMap[$rootClassName][$idHash];
+    }
+
+    /**
+     * INTERNAL:
+     * Tries to get an entity by its identifier hash. If no entity is found for
+     * the given hash, FALSE is returned.
+     *
+     * @ignore
+     * @param string $idHash
+     * @param string $rootClassName
+     * @return mixed The found entity or FALSE.
+     */
+    public function tryGetByIdHash($idHash, $rootClassName)
+    {
+        return isset($this->identityMap[$rootClassName][$idHash]) ?
+                $this->identityMap[$rootClassName][$idHash] : false;
+    }
+
+    /**
+     * Checks whether an entity is registered in the identity map of this UnitOfWork.
+     *
+     * @param object $entity
+     * @return boolean
+     */
+    public function isInIdentityMap($entity)
+    {
+        $oid = spl_object_hash($entity);
+        if ( ! isset($this->entityIdentifiers[$oid])) {
+            return false;
+        }
+        $classMetadata = $this->em->getClassMetadata(get_class($entity));
+        $idHash = implode(' ', $this->entityIdentifiers[$oid]);
+        if ($idHash === '') {
+            return false;
+        }
+        
+        return isset($this->identityMap[$classMetadata->rootEntityName][$idHash]);
+    }
+
+    /**
+     * INTERNAL:
+     * Checks whether an identifier hash exists in the identity map.
+     *
+     * @ignore
+     * @param string $idHash
+     * @param string $rootClassName
+     * @return boolean
+     */
+    public function containsIdHash($idHash, $rootClassName)
+    {
+        return isset($this->identityMap[$rootClassName][$idHash]);
+    }
+
+    /**
+     * Persists an entity as part of the current unit of work.
+     *
+     * @param object $entity The entity to persist.
+     */
+    public function persist($entity)
+    {
+        $visited = array();
+        $this->doPersist($entity, $visited);
+    }
+
+    /**
+     * Persists an entity as part of the current unit of work.
+     * 
+     * This method is internally called during persist() cascades as it tracks
+     * the already visited entities to prevent infinite recursions.
+     *
+     * @param object $entity The entity to persist.
+     * @param array $visited The already visited entities.
+     */
+    private function doPersist($entity, array &$visited)
+    {
+        $oid = spl_object_hash($entity);
+        if (isset($visited[$oid])) {
+            return; // Prevent infinite recursion
+        }
+
+        $visited[$oid] = $entity; // Mark visited
+
+        $class = $this->em->getClassMetadata(get_class($entity));
+
+        // We assume NEW, so DETACHED entities result in an exception on flush (constraint violation).
+        // If we would detect DETACHED here we would throw an exception anyway with the same
+        // consequences (not recoverable/programming error), so just assuming NEW here
+        // lets us avoid some database lookups for entities with natural identifiers.
+        $entityState = $this->getEntityState($entity, self::STATE_NEW);
+
+        switch ($entityState) {
+            case self::STATE_MANAGED:
+                // Nothing to do, except if policy is "deferred explicit"
+                if ($class->isChangeTrackingDeferredExplicit()) {
+                    $this->scheduleForDirtyCheck($entity);
+                }
+                break;
+            case self::STATE_NEW:
+                $this->persistNew($class, $entity);
+                break;
+            case self::STATE_REMOVED:
+                // Entity becomes managed again
+                unset($this->entityDeletions[$oid]);
+                $this->entityStates[$oid] = self::STATE_MANAGED;
+                break;
+            case self::STATE_DETACHED:
+                // Can actually not happen right now since we assume STATE_NEW.
+                throw new InvalidArgumentException("Detached entity passed to persist().");
+            default:
+                throw new UnexpectedValueException("Unexpected entity state: $entityState.");
+        }
+
+        $this->cascadePersist($entity, $visited);
+    }
+
+    /**
+     * Deletes an entity as part of the current unit of work.
+     *
+     * @param object $entity The entity to remove.
+     */
+    public function remove($entity)
+    {
+        $visited = array();
+        $this->doRemove($entity, $visited);
+    }
+
+    /**
+     * Deletes an entity as part of the current unit of work.
+     *
+     * This method is internally called during delete() cascades as it tracks
+     * the already visited entities to prevent infinite recursions.
+     *
+     * @param object $entity The entity to delete.
+     * @param array $visited The map of the already visited entities.
+     * @throws InvalidArgumentException If the instance is a detached entity.
+     */
+    private function doRemove($entity, array &$visited)
+    {
+        $oid = spl_object_hash($entity);
+        if (isset($visited[$oid])) {
+            return; // Prevent infinite recursion
+        }
+
+        $visited[$oid] = $entity; // mark visited
+        
+        // Cascade first, because scheduleForDelete() removes the entity from the identity map, which 
+        // can cause problems when a lazy proxy has to be initialized for the cascade operation.
+        $this->cascadeRemove($entity, $visited);
+
+        $class = $this->em->getClassMetadata(get_class($entity));
+        $entityState = $this->getEntityState($entity);
+        switch ($entityState) {
+            case self::STATE_NEW:
+            case self::STATE_REMOVED:
+                // nothing to do
+                break;
+            case self::STATE_MANAGED:
+                if (isset($class->lifecycleCallbacks[Events::preRemove])) {
+                    $class->invokeLifecycleCallbacks(Events::preRemove, $entity);
+                }
+                if ($this->evm->hasListeners(Events::preRemove)) {
+                    $this->evm->dispatchEvent(Events::preRemove, new LifecycleEventArgs($entity, $this->em));
+                }
+                $this->scheduleForDelete($entity);
+                break;
+            case self::STATE_DETACHED:
+                throw new InvalidArgumentException("A detached entity can not be removed.");
+            default:
+                throw new UnexpectedValueException("Unexpected entity state: $entityState.");
+        }
+
+    }
+
+    /**
+     * Merges the state of the given detached entity into this UnitOfWork.
+     *
+     * @param object $entity
+     * @return object The managed copy of the entity.
+     * @throws OptimisticLockException If the entity uses optimistic locking through a version
+     *         attribute and the version check against the managed copy fails.
+     *
+     * @todo Require active transaction!? OptimisticLockException may result in undefined state!?
+     */
+    public function merge($entity)
+    {
+        $visited = array();
+        return $this->doMerge($entity, $visited);
+    }
+
+    /**
+     * Executes a merge operation on an entity.
+     *
+     * @param object $entity
+     * @param array $visited
+     * @return object The managed copy of the entity.
+     * @throws OptimisticLockException If the entity uses optimistic locking through a version
+     *         attribute and the version check against the managed copy fails.
+     * @throws InvalidArgumentException If the entity instance is NEW.
+     */
+    private function doMerge($entity, array &$visited, $prevManagedCopy = null, $assoc = null)
+    {
+        $oid = spl_object_hash($entity);
+        if (isset($visited[$oid])) {
+            return; // Prevent infinite recursion
+        }
+
+        $visited[$oid] = $entity; // mark visited
+
+        $class = $this->em->getClassMetadata(get_class($entity));
+
+        // First we assume DETACHED, although it can still be NEW but we can avoid
+        // an extra db-roundtrip this way. If it is not MANAGED but has an identity,
+        // we need to fetch it from the db anyway in order to merge.
+        // MANAGED entities are ignored by the merge operation.
+        if ($this->getEntityState($entity, self::STATE_DETACHED) == self::STATE_MANAGED) {
+            $managedCopy = $entity;
+        } else {
+            // Try to look the entity up in the identity map.
+            $id = $class->getIdentifierValues($entity);
+
+            // If there is no ID, it is actually NEW.
+            if ( ! $id) {
+                $managedCopy = $class->newInstance();
+                $this->persistNew($class, $managedCopy);
+            } else {
+                $managedCopy = $this->tryGetById($id, $class->rootEntityName);
+                if ($managedCopy) {
+                    // We have the entity in-memory already, just make sure its not removed.
+                    if ($this->getEntityState($managedCopy) == self::STATE_REMOVED) {
+                        throw new InvalidArgumentException('Removed entity detected during merge.'
+                                . ' Can not merge with a removed entity.');
+                    }
+                } else {
+                    // We need to fetch the managed copy in order to merge.
+                    $managedCopy = $this->em->find($class->name, $id);
+                }
+
+                if ($managedCopy === null) {
+                    // If the identifier is ASSIGNED, it is NEW, otherwise an error
+                    // since the managed entity was not found.
+                    if ($class->isIdentifierNatural()) {
+                        $managedCopy = $class->newInstance();
+                        $class->setIdentifierValues($managedCopy, $id);
+                        $this->persistNew($class, $managedCopy);
+                    } else {
+                        throw new EntityNotFoundException;
+                    }
+                }
+            }
+
+            if ($class->isVersioned) {
+                $managedCopyVersion = $class->reflFields[$class->versionField]->getValue($managedCopy);
+                $entityVersion = $class->reflFields[$class->versionField]->getValue($entity);
+                // Throw exception if versions dont match.
+                if ($managedCopyVersion != $entityVersion) {
+                    throw OptimisticLockException::lockFailedVersionMissmatch($entity, $entityVersion, $managedCopyVersion);
+                }
+            }
+
+            // Merge state of $entity into existing (managed) entity
+            foreach ($class->reflFields as $name => $prop) {
+                if ( ! isset($class->associationMappings[$name])) {
+                    if ( ! $class->isIdentifier($name)) {
+                        $prop->setValue($managedCopy, $prop->getValue($entity));
+                    }
+                } else {
+                    $assoc2 = $class->associationMappings[$name];
+                    if ($assoc2['type'] & ClassMetadata::TO_ONE) {
+                        $other = $prop->getValue($entity);
+                        if ($other === null) {
+                            $prop->setValue($managedCopy, null);
+                        } else if ($other instanceof Proxy && !$other->__isInitialized__) {
+                            // do not merge fields marked lazy that have not been fetched.
+                            continue;
+                        } else if ( ! $assoc2['isCascadeMerge']) {
+                            if ($this->getEntityState($other, self::STATE_DETACHED) == self::STATE_MANAGED) {
+                                $prop->setValue($managedCopy, $other);
+                            } else {
+                                $targetClass = $this->em->getClassMetadata($assoc2['targetEntity']);
+                                $id = $targetClass->getIdentifierValues($other);
+                                $proxy = $this->em->getProxyFactory()->getProxy($assoc2['targetEntity'], $id);
+                                $prop->setValue($managedCopy, $proxy);
+                                $this->registerManaged($proxy, $id, array());
+                            }
+                        }
+                    } else {
+                        $mergeCol = $prop->getValue($entity);
+                        if ($mergeCol instanceof PersistentCollection && !$mergeCol->isInitialized()) {
+                            // do not merge fields marked lazy that have not been fetched.
+                            // keep the lazy persistent collection of the managed copy.
+                            continue;
+                        }
+
+                        $managedCol = $prop->getValue($managedCopy);
+                        if (!$managedCol) {
+                            $managedCol = new PersistentCollection($this->em,
+                                    $this->em->getClassMetadata($assoc2['targetEntity']),
+                                    new ArrayCollection
+                                    );
+                            $managedCol->setOwner($managedCopy, $assoc2);
+                            $prop->setValue($managedCopy, $managedCol);
+                            $this->originalEntityData[$oid][$name] = $managedCol;
+                        }
+                        if ($assoc2['isCascadeMerge']) {
+                            $managedCol->initialize();
+                            // clear and set dirty a managed collection if its not also the same collection to merge from.
+                            if (!$managedCol->isEmpty() && $managedCol != $mergeCol) {
+                                $managedCol->unwrap()->clear();
+                                $managedCol->setDirty(true);
+                                if ($assoc2['isOwningSide'] && $assoc2['type'] == ClassMetadata::MANY_TO_MANY && $class->isChangeTrackingNotify()) {
+                                    $this->scheduleForDirtyCheck($managedCopy);
+                                }
+                            }
+                        }
+                    }
+                }
+                if ($class->isChangeTrackingNotify()) {
+                    // Just treat all properties as changed, there is no other choice.
+                    $this->propertyChanged($managedCopy, $name, null, $prop->getValue($managedCopy));
+                }
+            }
+            if ($class->isChangeTrackingDeferredExplicit()) {
+                $this->scheduleForDirtyCheck($entity);
+            }
+        }
+
+        if ($prevManagedCopy !== null) {
+            $assocField = $assoc['fieldName'];
+            $prevClass = $this->em->getClassMetadata(get_class($prevManagedCopy));
+            if ($assoc['type'] & ClassMetadata::TO_ONE) {
+                $prevClass->reflFields[$assocField]->setValue($prevManagedCopy, $managedCopy);
+            } else {
+                $prevClass->reflFields[$assocField]->getValue($prevManagedCopy)->add($managedCopy);
+                if ($assoc['type'] == ClassMetadata::ONE_TO_MANY) {
+                    $class->reflFields[$assoc['mappedBy']]->setValue($managedCopy, $prevManagedCopy);
+                }
+            }
+        }
+
+        // Mark the managed copy visited as well
+        $visited[spl_object_hash($managedCopy)] = true;
+
+        $this->cascadeMerge($entity, $managedCopy, $visited);
+
+        return $managedCopy;
+    }
+    
+    /**
+     * Detaches an entity from the persistence management. It's persistence will
+     * no longer be managed by Doctrine.
+     *
+     * @param object $entity The entity to detach.
+     */
+    public function detach($entity)
+    {
+        $visited = array();
+        $this->doDetach($entity, $visited);
+    }
+    
+    /**
+     * Executes a detach operation on the given entity.
+     * 
+     * @param object $entity
+     * @param array $visited
+     */
+    private function doDetach($entity, array &$visited)
+    {
+        $oid = spl_object_hash($entity);
+        if (isset($visited[$oid])) {
+            return; // Prevent infinite recursion
+        }
+
+        $visited[$oid] = $entity; // mark visited
+        
+        switch ($this->getEntityState($entity, self::STATE_DETACHED)) {
+            case self::STATE_MANAGED:
+                if ($this->isInIdentityMap($entity)) {
+                    $this->removeFromIdentityMap($entity);
+                }
+                unset($this->entityInsertions[$oid], $this->entityUpdates[$oid],
+                        $this->entityDeletions[$oid], $this->entityIdentifiers[$oid],
+                        $this->entityStates[$oid], $this->originalEntityData[$oid]);
+                break;
+            case self::STATE_NEW:
+            case self::STATE_DETACHED:
+                return;
+        }
+        
+        $this->cascadeDetach($entity, $visited);
+    }
+    
+    /**
+     * Refreshes the state of the given entity from the database, overwriting
+     * any local, unpersisted changes.
+     * 
+     * @param object $entity The entity to refresh.
+     * @throws InvalidArgumentException If the entity is not MANAGED.
+     */
+    public function refresh($entity)
+    {
+        $visited = array();
+        $this->doRefresh($entity, $visited);
+    }
+    
+    /**
+     * Executes a refresh operation on an entity.
+     * 
+     * @param object $entity The entity to refresh.
+     * @param array $visited The already visited entities during cascades.
+     * @throws InvalidArgumentException If the entity is not MANAGED.
+     */
+    private function doRefresh($entity, array &$visited)
+    {
+        $oid = spl_object_hash($entity);
+        if (isset($visited[$oid])) {
+            return; // Prevent infinite recursion
+        }
+
+        $visited[$oid] = $entity; // mark visited
+
+        $class = $this->em->getClassMetadata(get_class($entity));
+        if ($this->getEntityState($entity) == self::STATE_MANAGED) {
+            $this->getEntityPersister($class->name)->refresh(
+                array_combine($class->getIdentifierFieldNames(), $this->entityIdentifiers[$oid]),
+                $entity
+            );
+        } else {
+            throw new InvalidArgumentException("Entity is not MANAGED.");
+        }
+        
+        $this->cascadeRefresh($entity, $visited);
+    }
+    
+    /**
+     * Cascades a refresh operation to associated entities.
+     *
+     * @param object $entity
+     * @param array $visited
+     */
+    private function cascadeRefresh($entity, array &$visited)
+    {
+        $class = $this->em->getClassMetadata(get_class($entity));
+        foreach ($class->associationMappings as $assoc) {
+            if ( ! $assoc['isCascadeRefresh']) {
+                continue;
+            }
+            $relatedEntities = $class->reflFields[$assoc['fieldName']]->getValue($entity);
+            if ($relatedEntities instanceof Collection) {
+                if ($relatedEntities instanceof PersistentCollection) {
+                    // Unwrap so that foreach() does not initialize
+                    $relatedEntities = $relatedEntities->unwrap();
+                }
+                foreach ($relatedEntities as $relatedEntity) {
+                    $this->doRefresh($relatedEntity, $visited);
+                }
+            } else if ($relatedEntities !== null) {
+                $this->doRefresh($relatedEntities, $visited);
+            }
+        }
+    }
+    
+    /**
+     * Cascades a detach operation to associated entities.
+     *
+     * @param object $entity
+     * @param array $visited
+     */
+    private function cascadeDetach($entity, array &$visited)
+    {
+        $class = $this->em->getClassMetadata(get_class($entity));
+        foreach ($class->associationMappings as $assoc) {
+            if ( ! $assoc['isCascadeDetach']) {
+                continue;
+            }
+            $relatedEntities = $class->reflFields[$assoc['fieldName']]->getValue($entity);
+            if ($relatedEntities instanceof Collection) {
+                if ($relatedEntities instanceof PersistentCollection) {
+                    // Unwrap so that foreach() does not initialize
+                    $relatedEntities = $relatedEntities->unwrap();
+                }
+                foreach ($relatedEntities as $relatedEntity) {
+                    $this->doDetach($relatedEntity, $visited);
+                }
+            } else if ($relatedEntities !== null) {
+                $this->doDetach($relatedEntities, $visited);
+            }
+        }
+    }
+
+    /**
+     * Cascades a merge operation to associated entities.
+     *
+     * @param object $entity
+     * @param object $managedCopy
+     * @param array $visited
+     */
+    private function cascadeMerge($entity, $managedCopy, array &$visited)
+    {
+        $class = $this->em->getClassMetadata(get_class($entity));
+        foreach ($class->associationMappings as $assoc) {
+            if ( ! $assoc['isCascadeMerge']) {
+                continue;
+            }
+            $relatedEntities = $class->reflFields[$assoc['fieldName']]->getValue($entity);
+            if ($relatedEntities instanceof Collection) {
+                if ($relatedEntities === $class->reflFields[$assoc['fieldName']]->getValue($managedCopy)) {
+                    continue;
+                }
+
+                if ($relatedEntities instanceof PersistentCollection) {
+                    // Unwrap so that foreach() does not initialize
+                    $relatedEntities = $relatedEntities->unwrap();
+                }
+                foreach ($relatedEntities as $relatedEntity) {
+                    $this->doMerge($relatedEntity, $visited, $managedCopy, $assoc);
+                }
+            } else if ($relatedEntities !== null) {
+                $this->doMerge($relatedEntities, $visited, $managedCopy, $assoc);
+            }
+        }
+    }
+
+    /**
+     * Cascades the save operation to associated entities.
+     *
+     * @param object $entity
+     * @param array $visited
+     * @param array $insertNow
+     */
+    private function cascadePersist($entity, array &$visited)
+    {
+        $class = $this->em->getClassMetadata(get_class($entity));
+        foreach ($class->associationMappings as $assoc) {
+            if ( ! $assoc['isCascadePersist']) {
+                continue;
+            }
+            
+            $relatedEntities = $class->reflFields[$assoc['fieldName']]->getValue($entity);
+            if (($relatedEntities instanceof Collection || is_array($relatedEntities))) {
+                if ($relatedEntities instanceof PersistentCollection) {
+                    // Unwrap so that foreach() does not initialize
+                    $relatedEntities = $relatedEntities->unwrap();
+                }
+                foreach ($relatedEntities as $relatedEntity) {
+                    $this->doPersist($relatedEntity, $visited);
+                }
+            } else if ($relatedEntities !== null) {
+                $this->doPersist($relatedEntities, $visited);
+            }
+        }
+    }
+
+    /**
+     * Cascades the delete operation to associated entities.
+     *
+     * @param object $entity
+     * @param array $visited
+     */
+    private function cascadeRemove($entity, array &$visited)
+    {
+        $class = $this->em->getClassMetadata(get_class($entity));
+        foreach ($class->associationMappings as $assoc) {
+            if ( ! $assoc['isCascadeRemove']) {
+                continue;
+            }
+            
+            if ($entity instanceof Proxy && !$entity->__isInitialized__) {
+                $entity->__load();
+            }
+            
+            $relatedEntities = $class->reflFields[$assoc['fieldName']]->getValue($entity);
+            if ($relatedEntities instanceof Collection || is_array($relatedEntities)) {
+                // If its a PersistentCollection initialization is intended! No unwrap!
+                foreach ($relatedEntities as $relatedEntity) {
+                    $this->doRemove($relatedEntity, $visited);
+                }
+            } else if ($relatedEntities !== null) {
+                $this->doRemove($relatedEntities, $visited);
+            }
+        }
+    }
+
+    /**
+     * Acquire a lock on the given entity.
+     *
+     * @param object $entity
+     * @param int $lockMode
+     * @param int $lockVersion
+     */
+    public function lock($entity, $lockMode, $lockVersion = null)
+    {
+        if ($this->getEntityState($entity) != self::STATE_MANAGED) {
+            throw new InvalidArgumentException("Entity is not MANAGED.");
+        }
+        
+        $entityName = get_class($entity);
+        $class = $this->em->getClassMetadata($entityName);
+
+        if ($lockMode == \Doctrine\DBAL\LockMode::OPTIMISTIC) {
+            if (!$class->isVersioned) {
+                throw OptimisticLockException::notVersioned($entityName);
+            }
+
+            if ($lockVersion != null) {
+                $entityVersion = $class->reflFields[$class->versionField]->getValue($entity);
+                if ($entityVersion != $lockVersion) {
+                    throw OptimisticLockException::lockFailedVersionMissmatch($entity, $lockVersion, $entityVersion);
+                }
+            }
+        } else if (in_array($lockMode, array(\Doctrine\DBAL\LockMode::PESSIMISTIC_READ, \Doctrine\DBAL\LockMode::PESSIMISTIC_WRITE))) {
+
+            if (!$this->em->getConnection()->isTransactionActive()) {
+                throw TransactionRequiredException::transactionRequired();
+            }
+            
+            $oid = spl_object_hash($entity);
+
+            $this->getEntityPersister($class->name)->lock(
+                array_combine($class->getIdentifierFieldNames(), $this->entityIdentifiers[$oid]),
+                $lockMode
+            );
+        }
+    }
+
+    /**
+     * Gets the CommitOrderCalculator used by the UnitOfWork to order commits.
+     *
+     * @return Doctrine\ORM\Internal\CommitOrderCalculator
+     */
+    public function getCommitOrderCalculator()
+    {
+        if ($this->commitOrderCalculator === null) {
+            $this->commitOrderCalculator = new Internal\CommitOrderCalculator;
+        }
+        return $this->commitOrderCalculator;
+    }
+
+    /**
+     * Clears the UnitOfWork.
+     */
+    public function clear()
+    {
+        $this->identityMap =
+        $this->entityIdentifiers =
+        $this->originalEntityData =
+        $this->entityChangeSets =
+        $this->entityStates =
+        $this->scheduledForDirtyCheck =
+        $this->entityInsertions =
+        $this->entityUpdates =
+        $this->entityDeletions =
+        $this->collectionDeletions =
+        $this->collectionUpdates =
+        $this->extraUpdates =
+        $this->orphanRemovals = array();
+        if ($this->commitOrderCalculator !== null) {
+            $this->commitOrderCalculator->clear();
+        }
+
+        if ($this->evm->hasListeners(Events::onClear)) {
+            $this->evm->dispatchEvent(Events::onClear, new Event\OnClearEventArgs($this->em));
+        }
+    }
+    
+    /**
+     * INTERNAL:
+     * Schedules an orphaned entity for removal. The remove() operation will be
+     * invoked on that entity at the beginning of the next commit of this
+     * UnitOfWork.
+     * 
+     * @ignore
+     * @param object $entity
+     */
+    public function scheduleOrphanRemoval($entity)
+    {
+        $this->orphanRemovals[spl_object_hash($entity)] = $entity;
+    }
+    
+    /**
+     * INTERNAL:
+     * Schedules a complete collection for removal when this UnitOfWork commits.
+     *
+     * @param PersistentCollection $coll
+     */
+    public function scheduleCollectionDeletion(PersistentCollection $coll)
+    {
+        //TODO: if $coll is already scheduled for recreation ... what to do?
+        // Just remove $coll from the scheduled recreations?
+        $this->collectionDeletions[] = $coll;
+    }
+
+    public function isCollectionScheduledForDeletion(PersistentCollection $coll)
+    {
+        return in_array($coll, $this->collectionsDeletions, true);
+    }
+
+    /**
+     * INTERNAL:
+     * Creates an entity. Used for reconstitution of persistent entities.
+     *
+     * @ignore
+     * @param string $className The name of the entity class.
+     * @param array $data The data for the entity.
+     * @param array $hints Any hints to account for during reconstitution/lookup of the entity.
+     * @return object The managed entity instance.
+     * @internal Highly performance-sensitive method.
+     * 
+     * @todo Rename: getOrCreateEntity
+     */
+    public function createEntity($className, array $data, &$hints = array())
+    {
+        $class = $this->em->getClassMetadata($className);
+        //$isReadOnly = isset($hints[Query::HINT_READ_ONLY]);
+
+        if ($class->isIdentifierComposite) {
+            $id = array();
+            foreach ($class->identifier as $fieldName) {
+                if (isset($class->associationMappings[$fieldName])) {
+                    $id[$fieldName] = $data[$class->associationMappings[$fieldName]['joinColumns'][0]['name']];
+                } else {
+                    $id[$fieldName] = $data[$fieldName];
+                }
+            }
+            $idHash = implode(' ', $id);
+        } else {
+            if (isset($class->associationMappings[$class->identifier[0]])) {
+                $idHash = $data[$class->associationMappings[$class->identifier[0]]['joinColumns'][0]['name']];
+            } else {
+                $idHash = $data[$class->identifier[0]];
+            }
+            $id = array($class->identifier[0] => $idHash);
+        }
+        
+        if (isset($this->identityMap[$class->rootEntityName][$idHash])) {            
+            $entity = $this->identityMap[$class->rootEntityName][$idHash];
+            $oid = spl_object_hash($entity);
+            if ($entity instanceof Proxy && ! $entity->__isInitialized__) {
+                $entity->__isInitialized__ = true;
+                $overrideLocalValues = true;
+                if ($entity instanceof NotifyPropertyChanged) {
+                    $entity->addPropertyChangedListener($this);
+                }
+            } else {
+                $overrideLocalValues = isset($hints[Query::HINT_REFRESH]);
+            }
+
+            if ($overrideLocalValues) {
+                $this->originalEntityData[$oid] = $data;
+            }
+        } else {
+            $entity = $class->newInstance();
+            $oid = spl_object_hash($entity);
+            $this->entityIdentifiers[$oid] = $id;
+            $this->entityStates[$oid] = self::STATE_MANAGED;
+            $this->originalEntityData[$oid] = $data;
+            $this->identityMap[$class->rootEntityName][$idHash] = $entity;
+            if ($entity instanceof NotifyPropertyChanged) {
+                $entity->addPropertyChangedListener($this);
+            }
+            $overrideLocalValues = true;
+        }
+
+        if ($overrideLocalValues) {
+            foreach ($data as $field => $value) {
+                if (isset($class->fieldMappings[$field])) {
+                    $class->reflFields[$field]->setValue($entity, $value);
+                }
+            }
+
+            // Loading the entity right here, if its in the eager loading map get rid of it there.
+            unset($this->eagerLoadingEntities[$class->rootEntityName][$idHash]);
+            
+            // Properly initialize any unfetched associations, if partial objects are not allowed.
+            if ( ! isset($hints[Query::HINT_FORCE_PARTIAL_LOAD])) {
+                foreach ($class->associationMappings as $field => $assoc) {
+                    // Check if the association is not among the fetch-joined associations already.
+                    if (isset($hints['fetched'][$className][$field])) {
+                        continue;
+                    }
+
+                    $targetClass = $this->em->getClassMetadata($assoc['targetEntity']);
+
+                    if ($assoc['type'] & ClassMetadata::TO_ONE) {
+                        if ($assoc['isOwningSide']) {
+                            $associatedId = array();
+                            // TODO: Is this even computed right in all cases of composite keys?
+                            foreach ($assoc['targetToSourceKeyColumns'] as $targetColumn => $srcColumn) {
+                                $joinColumnValue = isset($data[$srcColumn]) ? $data[$srcColumn] : null;
+                                if ($joinColumnValue !== null) {
+                                    if ($targetClass->containsForeignIdentifier) {
+                                        $associatedId[$targetClass->getFieldForColumn($targetColumn)] = $joinColumnValue;
+                                    } else {
+                                        $associatedId[$targetClass->fieldNames[$targetColumn]] = $joinColumnValue;
+                                    }
+                                }
+                            }
+                            if ( ! $associatedId) {
+                                // Foreign key is NULL
+                                $class->reflFields[$field]->setValue($entity, null);
+                                $this->originalEntityData[$oid][$field] = null;
+                            } else {
+                                if (!isset($hints['fetchMode'][$class->name][$field])) {
+                                    $hints['fetchMode'][$class->name][$field] = $assoc['fetch'];
+                                }
+
+                                // Foreign key is set
+                                // Check identity map first
+                                // FIXME: Can break easily with composite keys if join column values are in
+                                //        wrong order. The correct order is the one in ClassMetadata#identifier.
+                                $relatedIdHash = implode(' ', $associatedId);
+                                if (isset($this->identityMap[$targetClass->rootEntityName][$relatedIdHash])) {
+                                    $newValue = $this->identityMap[$targetClass->rootEntityName][$relatedIdHash];
+                                    
+                                    // if this is an uninitialized proxy, we are deferring eager loads,
+                                    // this association is marked as eager fetch, and its an uninitialized proxy (wtf!)
+                                    // then we cann append this entity for eager loading!
+                                    if ($hints['fetchMode'][$class->name][$field] == ClassMetadata::FETCH_EAGER &&
+                                        isset($hints['deferEagerLoad']) &&
+                                        !$targetClass->isIdentifierComposite &&
+                                        $newValue instanceof Proxy &&
+                                        $newValue->__isInitialized__ === false) {
+                                        
+                                        $this->eagerLoadingEntities[$targetClass->rootEntityName][$relatedIdHash] = current($associatedId);
+                                    }
+                                } else {
+                                    if ($targetClass->subClasses) {
+                                        // If it might be a subtype, it can not be lazy. There isn't even
+                                        // a way to solve this with deferred eager loading, which means putting
+                                        // an entity with subclasses at a *-to-one location is really bad! (performance-wise)
+                                        $newValue = $this->getEntityPersister($assoc['targetEntity'])
+                                                ->loadOneToOneEntity($assoc, $entity, $associatedId);
+                                    } else {
+                                        // Deferred eager load only works for single identifier classes
+
+                                        if ($hints['fetchMode'][$class->name][$field] == ClassMetadata::FETCH_EAGER) {
+                                            if (isset($hints['deferEagerLoad']) && !$targetClass->isIdentifierComposite) {
+                                                // TODO: Is there a faster approach?
+                                                $this->eagerLoadingEntities[$targetClass->rootEntityName][$relatedIdHash] = current($associatedId);
+
+                                                $newValue = $this->em->getProxyFactory()->getProxy($assoc['targetEntity'], $associatedId);
+                                            } else {
+                                                // TODO: This is very imperformant, ignore it?
+                                                $newValue = $this->em->find($assoc['targetEntity'], $associatedId);
+                                            }
+                                        } else {
+                                            $newValue = $this->em->getProxyFactory()->getProxy($assoc['targetEntity'], $associatedId);
+                                        }
+                                        // PERF: Inlined & optimized code from UnitOfWork#registerManaged()
+                                        $newValueOid = spl_object_hash($newValue);
+                                        $this->entityIdentifiers[$newValueOid] = $associatedId;
+                                        $this->identityMap[$targetClass->rootEntityName][$relatedIdHash] = $newValue;
+                                        $this->entityStates[$newValueOid] = self::STATE_MANAGED;
+                                        // make sure that when an proxy is then finally loaded, $this->originalEntityData is set also!
+                                    }
+                                }
+                                $this->originalEntityData[$oid][$field] = $newValue;
+                                $class->reflFields[$field]->setValue($entity, $newValue);
+                                
+                                if ($assoc['inversedBy'] && $assoc['type'] & ClassMetadata::ONE_TO_ONE) {
+                                    $inverseAssoc = $targetClass->associationMappings[$assoc['inversedBy']];
+                                    $targetClass->reflFields[$inverseAssoc['fieldName']]->setValue($newValue, $entity);
+                                }
+                            }
+                        } else {
+                            // Inverse side of x-to-one can never be lazy
+                            $class->reflFields[$field]->setValue($entity, $this->getEntityPersister($assoc['targetEntity'])
+                                    ->loadOneToOneEntity($assoc, $entity));
+                        }
+                    } else {
+                        // Inject collection
+                        $pColl = new PersistentCollection($this->em, $targetClass, new ArrayCollection);
+                        $pColl->setOwner($entity, $assoc);
+
+                        $reflField = $class->reflFields[$field];
+                        $reflField->setValue($entity, $pColl);
+
+                        if ($assoc['fetch'] == ClassMetadata::FETCH_EAGER) {
+                            $this->loadCollection($pColl);
+                            $pColl->takeSnapshot();
+                        } else {
+                            $pColl->setInitialized(false);
+                        }
+                        $this->originalEntityData[$oid][$field] = $pColl;
+                    }
+                }
+            }
+        }
+        
+        //TODO: These should be invoked later, after hydration, because associations may not yet be loaded here.
+        if (isset($class->lifecycleCallbacks[Events::postLoad])) {
+            $class->invokeLifecycleCallbacks(Events::postLoad, $entity);
+        }
+        if ($this->evm->hasListeners(Events::postLoad)) {
+            $this->evm->dispatchEvent(Events::postLoad, new LifecycleEventArgs($entity, $this->em));
+        }
+
+        return $entity;
+    }
+
+    /**
+     * @return void
+     */
+    public function triggerEagerLoads()
+    {
+        if (!$this->eagerLoadingEntities) {
+            return;
+        }
+
+        // avoid infinite recursion
+        $eagerLoadingEntities = $this->eagerLoadingEntities;
+        $this->eagerLoadingEntities = array();
+
+        foreach ($eagerLoadingEntities AS $entityName => $ids) {
+            $class = $this->em->getClassMetadata($entityName);
+            $this->getEntityPersister($entityName)->loadAll(array_combine($class->identifier, array(array_values($ids))));
+        }
+    }
+
+    /**
+     * Initializes (loads) an uninitialized persistent collection of an entity.
+     *
+     * @param PeristentCollection $collection The collection to initialize.
+     * @todo Maybe later move to EntityManager#initialize($proxyOrCollection). See DDC-733.
+     */
+    public function loadCollection(PersistentCollection $collection)
+    {
+        $assoc = $collection->getMapping();
+        switch ($assoc['type']) {
+            case ClassMetadata::ONE_TO_MANY:
+                $this->getEntityPersister($assoc['targetEntity'])->loadOneToManyCollection(
+                        $assoc, $collection->getOwner(), $collection);
+                break;
+            case ClassMetadata::MANY_TO_MANY:
+                $this->getEntityPersister($assoc['targetEntity'])->loadManyToManyCollection(
+                        $assoc, $collection->getOwner(), $collection);
+                break;
+        }
+    }
+
+    /**
+     * Gets the identity map of the UnitOfWork.
+     *
+     * @return array
+     */
+    public function getIdentityMap()
+    {
+        return $this->identityMap;
+    }
+
+    /**
+     * Gets the original data of an entity. The original data is the data that was
+     * present at the time the entity was reconstituted from the database.
+     *
+     * @param object $entity
+     * @return array
+     */
+    public function getOriginalEntityData($entity)
+    {
+        $oid = spl_object_hash($entity);
+        if (isset($this->originalEntityData[$oid])) {
+            return $this->originalEntityData[$oid];
+        }
+        return array();
+    }
+    
+    /**
+     * @ignore
+     */
+    public function setOriginalEntityData($entity, array $data)
+    {
+        $this->originalEntityData[spl_object_hash($entity)] = $data;
+    }
+
+    /**
+     * INTERNAL:
+     * Sets a property value of the original data array of an entity.
+     *
+     * @ignore
+     * @param string $oid
+     * @param string $property
+     * @param mixed $value
+     */
+    public function setOriginalEntityProperty($oid, $property, $value)
+    {
+        $this->originalEntityData[$oid][$property] = $value;
+    }
+
+    /**
+     * Gets the identifier of an entity.
+     * The returned value is always an array of identifier values. If the entity
+     * has a composite identifier then the identifier values are in the same
+     * order as the identifier field names as returned by ClassMetadata#getIdentifierFieldNames().
+     *
+     * @param object $entity
+     * @return array The identifier values.
+     */
+    public function getEntityIdentifier($entity)
+    {        
+        return $this->entityIdentifiers[spl_object_hash($entity)];
+    }
+
+    /**
+     * Tries to find an entity with the given identifier in the identity map of
+     * this UnitOfWork.
+     *
+     * @param mixed $id The entity identifier to look for.
+     * @param string $rootClassName The name of the root class of the mapped entity hierarchy.
+     * @return mixed Returns the entity with the specified identifier if it exists in
+     *               this UnitOfWork, FALSE otherwise.
+     */
+    public function tryGetById($id, $rootClassName)
+    {
+        $idHash = implode(' ', (array) $id);
+        if (isset($this->identityMap[$rootClassName][$idHash])) {
+            return $this->identityMap[$rootClassName][$idHash];
+        }
+        return false;
+    }
+
+    /**
+     * Schedules an entity for dirty-checking at commit-time.
+     *
+     * @param object $entity The entity to schedule for dirty-checking.
+     * @todo Rename: scheduleForSynchronization
+     */
+    public function scheduleForDirtyCheck($entity)
+    {
+        $rootClassName = $this->em->getClassMetadata(get_class($entity))->rootEntityName;
+        $this->scheduledForDirtyCheck[$rootClassName][spl_object_hash($entity)] = $entity;
+    }
+
+    /**
+     * Checks whether the UnitOfWork has any pending insertions.
+     *
+     * @return boolean TRUE if this UnitOfWork has pending insertions, FALSE otherwise.
+     */
+    public function hasPendingInsertions()
+    {
+        return ! empty($this->entityInsertions);
+    }
+
+    /**
+     * Calculates the size of the UnitOfWork. The size of the UnitOfWork is the
+     * number of entities in the identity map.
+     *
+     * @return integer
+     */
+    public function size()
+    {
+        $count = 0;
+        foreach ($this->identityMap as $entitySet) {
+            $count += count($entitySet);
+        }
+        return $count;
+    }
+
+    /**
+     * Gets the EntityPersister for an Entity.
+     *
+     * @param string $entityName  The name of the Entity.
+     * @return Doctrine\ORM\Persisters\AbstractEntityPersister
+     */
+    public function getEntityPersister($entityName)
+    {
+        if ( ! isset($this->persisters[$entityName])) {
+            $class = $this->em->getClassMetadata($entityName);
+            if ($class->isInheritanceTypeNone()) {
+                $persister = new Persisters\BasicEntityPersister($this->em, $class);
+            } else if ($class->isInheritanceTypeSingleTable()) {
+                $persister = new Persisters\SingleTablePersister($this->em, $class);
+            } else if ($class->isInheritanceTypeJoined()) {
+                $persister = new Persisters\JoinedSubclassPersister($this->em, $class);
+            } else {
+                $persister = new Persisters\UnionSubclassPersister($this->em, $class);
+            }
+            $this->persisters[$entityName] = $persister;
+        }
+        return $this->persisters[$entityName];
+    }
+
+    /**
+     * Gets a collection persister for a collection-valued association.
+     *
+     * @param AssociationMapping $association
+     * @return AbstractCollectionPersister
+     */
+    public function getCollectionPersister(array $association)
+    {
+        $type = $association['type'];
+        if ( ! isset($this->collectionPersisters[$type])) {
+            if ($type == ClassMetadata::ONE_TO_MANY) {
+                $persister = new Persisters\OneToManyPersister($this->em);
+            } else if ($type == ClassMetadata::MANY_TO_MANY) {
+                $persister = new Persisters\ManyToManyPersister($this->em);
+            }
+            $this->collectionPersisters[$type] = $persister;
+        }
+        return $this->collectionPersisters[$type];
+    }
+
+    /**
+     * INTERNAL:
+     * Registers an entity as managed.
+     *
+     * @param object $entity The entity.
+     * @param array $id The identifier values.
+     * @param array $data The original entity data.
+     */
+    public function registerManaged($entity, array $id, array $data)
+    {
+        $oid = spl_object_hash($entity);
+        $this->entityIdentifiers[$oid] = $id;
+        $this->entityStates[$oid] = self::STATE_MANAGED;
+        $this->originalEntityData[$oid] = $data;
+        $this->addToIdentityMap($entity);
+    }
+
+    /**
+     * INTERNAL:
+     * Clears the property changeset of the entity with the given OID.
+     *
+     * @param string $oid The entity's OID.
+     */
+    public function clearEntityChangeSet($oid)
+    {
+        $this->entityChangeSets[$oid] = array();
+    }
+
+    /* PropertyChangedListener implementation */
+
+    /**
+     * Notifies this UnitOfWork of a property change in an entity.
+     *
+     * @param object $entity The entity that owns the property.
+     * @param string $propertyName The name of the property that changed.
+     * @param mixed $oldValue The old value of the property.
+     * @param mixed $newValue The new value of the property.
+     */
+    public function propertyChanged($entity, $propertyName, $oldValue, $newValue)
+    {
+        $oid = spl_object_hash($entity);
+        $class = $this->em->getClassMetadata(get_class($entity));
+
+        $isAssocField = isset($class->associationMappings[$propertyName]);
+
+        if ( ! $isAssocField && ! isset($class->fieldMappings[$propertyName])) {
+            return; // ignore non-persistent fields
+        }
+
+        // Update changeset and mark entity for synchronization
+        $this->entityChangeSets[$oid][$propertyName] = array($oldValue, $newValue);
+        if ( ! isset($this->scheduledForDirtyCheck[$class->rootEntityName][$oid])) {
+            $this->scheduleForDirtyCheck($entity);
+        }
+    }
+
+    /**
+     * Gets the currently scheduled entity insertions in this UnitOfWork.
+     * 
+     * @return array
+     */
+    public function getScheduledEntityInsertions()
+    {
+        return $this->entityInsertions;
+    }
+    
+    /**
+     * Gets the currently scheduled entity updates in this UnitOfWork.
+     * 
+     * @return array
+     */
+    public function getScheduledEntityUpdates()
+    {
+        return $this->entityUpdates;
+    }
+    
+    /**
+     * Gets the currently scheduled entity deletions in this UnitOfWork.
+     * 
+     * @return array
+     */
+    public function getScheduledEntityDeletions()
+    {
+        return $this->entityDeletions;
+    }
+
+    /**
+     * Get the currently scheduled complete collection deletions
+     *
+     * @return array
+     */
+    public function getScheduledCollectionDeletions()
+    {
+        return $this->collectionDeletions;
+    }
+
+    /**
+     * Gets the currently scheduled collection inserts, updates and deletes.
+     *
+     * @return array
+     */
+    public function getScheduledCollectionUpdates()
+    {
+        return $this->collectionUpdates;
+    }
+    
+    /**
+     * Helper method to initialize a lazy loading proxy or persistent collection.
+     * 
+     * @param object
+     * @return void
+     */
+    public function initializeObject($obj)
+    {
+        if ($obj instanceof Proxy) {
+            $obj->__load();
+        } else if ($obj instanceof PersistentCollection) {
+            $obj->initialize();
+        }
+    }
+    
+    /**
+     * Helper method to show an object as string.
+     * 
+     * @param  object $obj
+     * @return string 
+     */
+    private static function objToStr($obj)
+    {
+        return method_exists($obj, '__toString') ? (string)$obj : get_class($obj).'@'.spl_object_hash($obj);
+    }
+}