LiskMigrationIterator.php
d27e7c52b218stable

LiskMigrationIterator.php
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			<?php

			/**
			* Iterate over every object of a given type, without holding all of them in
			* memory. This is useful for performing database migrations.
			*
			* $things = new LiskMigrationIterator(new LiskThing());
			* foreach ($things as $thing) {
			* // do something
			* }
			*
			* NOTE: This only works on objects with a normal `id` column.
			*
			* @task storage
			*/
			final class LiskMigrationIterator extends PhutilBufferedIterator {

			private $object;
			private $cursor;
			private $set;

			public function __construct(LiskDAO $object) {
			$this->set = new LiskDAOSet();
			$this->object = $object->putInSet($this->set);
			}

			protected function didRewind() {
			$this->cursor = 0;
			}

			public function key() {
			return $this->current()->getID();
			}

			protected function loadPage() {
			$this->set->clearSet();

			$results = $this->object->loadAllWhere(
			'id > %d ORDER BY id ASC LIMIT %d',
			$this->cursor,
			$this->getPageSize());
			if ($results) {
			$this->cursor = last($results)->getID();
			}
			return $results;
			}

			}