Doctrine\ODM\MongoDB\UnitOfWork::computeChangeSets PHP Method

    public function computeChangeSets()
    {
        $this->computeScheduleInsertsChangeSets();
        $this->computeScheduleUpsertsChangeSets();
        // Compute changes for other MANAGED documents. Change tracking policies take effect here.
        foreach ($this->identityMap as $className => $documents) {
            $class = $this->dm->getClassMetadata($className);
            if ($class->isEmbeddedDocument) {
                /* we do not want to compute changes to embedded documents up front
                 * in case embedded document was replaced and its changeset
                 * would corrupt data. Embedded documents' change set will
                 * be calculated by reachability from owning document.
                 */
                continue;
            }
            // If change tracking is explicit or happens through notification, then only compute
            // changes on document of that type that are explicitly marked for synchronization.
            switch (true) {
                case $class->isChangeTrackingDeferredImplicit():
                    $documentsToProcess = $documents;
                    break;
                case isset($this->scheduledForDirtyCheck[$className]):
                    $documentsToProcess = $this->scheduledForDirtyCheck[$className];
                    break;
                default:
                    $documentsToProcess = array();
            }
            foreach ($documentsToProcess as $document) {
                // Ignore uninitialized proxy objects
                if ($document instanceof Proxy && !$document->__isInitialized__) {
                    continue;
                }
                // Only MANAGED documents that are NOT SCHEDULED FOR INSERTION, UPSERT OR DELETION are processed here.
                $oid = spl_object_hash($document);
                if (!isset($this->documentInsertions[$oid]) && !isset($this->documentUpserts[$oid]) && !isset($this->documentDeletions[$oid]) && isset($this->documentStates[$oid])) {
                    $this->computeChangeSet($class, $document);
                }
            }
        }
    }