better-testing

LiskMigrationIterator.php
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			<?php

			/*
			* Copyright 2012 Facebook, Inc.
			*
			* Licensed under the Apache License, Version 2.0 (the "License");
			* you may not use this file except in compliance with the License.
			* You may obtain a copy of the License at
			*
			* http://www.apache.org/licenses/LICENSE-2.0
			*
			* Unless required by applicable law or agreed to in writing, software
			* distributed under the License is distributed on an "AS IS" BASIS,
			* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
			* See the License for the specific language governing permissions and
			* limitations under the License.
			*/

			/**
			* 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;

			public function __construct(LiskDAO $object) {
			$this->object = $object;
			}

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

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

			protected function loadPage() {
			$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;
			}

			}