<?php
/*
* Copyright 2018 Google LLC
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* 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.
*/
namespace Google\ApiCore;
trait PollingTrait
{
/**
* @param callable $pollCallable The call to poll. Must return a boolean indicating whether the
* operation has completed, and the polling loop can be terminated.
* @param array $options {
* Options for configuring the polling behaviour.
*
* @type int $initialPollDelayMillis The initial polling interval to use, in milliseconds.
* @type int $pollDelayMultiplier Multiplier applied to the polling interval on each retry.
* @type int $maxPollDelayMillis The maximum polling interval to use, in milliseconds.
* @type int $totalPollTimeoutMillis The maximum amount of time to continue polling, in milliseconds.
* }
* @return bool
*/
private function poll(callable $pollCallable, array $options)
{
$currentPollDelayMillis = $options['initialPollDelayMillis'];
$pollDelayMultiplier = $options['pollDelayMultiplier'];
$maxPollDelayMillis = $options['maxPollDelayMillis'];
$totalPollTimeoutMillis = $options['totalPollTimeoutMillis'];
$hasTotalPollTimeout = $totalPollTimeoutMillis > 0.0;
$endTime = $this->getCurrentTimeMillis() + $totalPollTimeoutMillis;
while (true) {
if ($hasTotalPollTimeout && $this->getCurrentTimeMillis() > $endTime) {
return false;
}
$this->sleepMillis($currentPollDelayMillis);
if ($pollCallable()) {
return true;
}
$currentPollDelayMillis = min([
$currentPollDelayMillis * $pollDelayMultiplier,
$maxPollDelayMillis
]);
}
}
/**
* Protected to allow overriding for tests
*
* @return float Current time in milliseconds
*/
protected function getCurrentTimeMillis()
{
return microtime(true) * 1000.0;
}
/**
* Protected to allow overriding for tests
*
* @param int $millis
*/
protected function sleepMillis($millis)
{
usleep($millis * 1000);
}
}