agent/php/ElasticApm/Impl/ClockInterface.php

<?php

/*
 * Licensed to Elasticsearch B.V. under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch B.V. licenses this file to you 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.
 */

declare(strict_types=1);

namespace Elastic\Apm\Impl;

/**
 * Code in this file is part of implementation internals and thus it is not covered by the backward compatibility.
 *
 * @internal
 */
interface ClockInterface
{
    /**
     * @return float UTC based and in microseconds since Unix epoch
     *
     * @see ExecutionSegmentInterface::getTimestamp() For the description
     */
    public function getSystemClockCurrentTime(): float;

    /**
     * Clock that cannot be set and represents monotonic time since some unspecified starting point.
     * In microseconds.
     * Used to measure duration.
     *
     * @return float Monotonic time since some unspecified starting point in microseconds
     *
     * @see ExecutionSegmentInterface::end()
     */
    public function getMonotonicClockCurrentTime(): float;
}