If the storage was already bootstrapped this method returns silently.
While you could call bootstrap() on each request, you should not do that!
This method will do unnecessary storage communications just to see that
bootstrapping was performed already. You therefore should call that
method in your application's bootstrap or deploy process.
This method is threadsafe.
/**
* Initialize the a new token bucket, then proload that bucket with tokens
* @param string $bucketName The name of the bucket to create
* @param Rate $fillRate Rate Object used to define fill rate
* @return TokenBucket The initialized bucket
* @access private
*/
private function initializeBucket($bucketName, Rate $fillRate)
{
$storage = new PHPRedisStorage($bucketName, $this->redisObj);
$bucket = new TokenBucket(self::MAXBUCKETSIZE, $fillRate, $storage);
$bucket->bootstrap(self::MAXBUCKETSIZE);
return $bucket;
}
/**
* Test the capacity limit of the bucket
*
* @test
*/
public function testCapacity()
{
$rate = new Rate(1, Rate::SECOND);
$tokenBucket = new TokenBucket(10, $rate, new SingleProcessStorage());
$tokenBucket->bootstrap();
sleep(11);
$this->assertTrue($tokenBucket->consume(10));
$this->assertFalse($tokenBucket->consume(1));
}
/**
* Tests traffic shapping filtering.
*
* @param float $expectedDuration The expected duration in seconds.
* @param int[] $bytes The amount of bytes to write.
*
* @test
* @dataProvider provideTestFilterShapesTraffic
*/
public function testFilterShapesTraffic($expectedDuration, array $bytes)
{
$stream = fopen("php://memory", "w");
$bucket = new TokenBucket(10, new Rate(1, Rate::SECOND), new SingleProcessStorage());
$bucket->bootstrap();
stream_filter_register("test", TokenBucketFilter::class);
$this->filter = stream_filter_append($stream, "test", STREAM_FILTER_WRITE, $bucket);
$time = microtime(true);
foreach ($bytes as $byte) {
fwrite($stream, str_repeat(" ", $byte));
}
fclose($stream);
$this->assertLessThan(0.001, abs(microtime(true) - $time - $expectedDuration));
}
/**
* Throttles a stream to the given rate.
*
* This registers a filter to the given stream which does the traffic
* shaping. After that any stream operation is throttled.
*
* The stream can be an input or an output stream.
*
* This object can throttle only one stream at a time. If you want to
* call throttle() again, make either sure you called {@link unthrottle()}
* before or use a new instance.
*
* @param resource $stream The stream.
*
* @throws BandwidthThrottleException Error during throtteling the stream.
* @throws \LengthException The initial burst size was greater than the burst size.
*/
public function throttle($stream)
{
try {
if (is_resource($this->filter)) {
throw new BandwidthThrottleException("This throttle is still attached to a stream. Call unthrottle() or use a new instance.");
}
$this->registerOnce();
$capacity = empty($this->capacity) ? $this->rate->getTokensPerSecond() : $this->capacity;
$bucket = new TokenBucket($capacity, $this->rate, $this->storage);
$bucket->bootstrap($this->initialTokens);
$this->filter = stream_filter_append($stream, self::FILTER_NAME, $this->filterMode, $bucket);
if (!is_resource($this->filter)) {
throw new BandwidthThrottleException("Could not throttle the stream.");
}
} catch (StorageException $e) {
throw new BandwidthThrottleException("Could not initialize token bucket.", 0, $e);
}
}
/**
* Tests consume() won't sleep less than one millisecond.
*
* @test
*/
public function testMinimumSleep()
{
$rate = new Rate(10, Rate::MILLISECOND);
$bucket = new TokenBucket(1, $rate, new SingleProcessStorage());
$bucket->bootstrap();
$consumer = new BlockingConsumer($bucket);
$time = microtime(true);
$consumer->consume(1);
$this->assertLessThan(1.0E-5, abs(microtime(true) - $time - 0.001));
}
/**
* After waiting longer than the complete refill period on an empty bucket,
* getTokens() should return the capacity of the bucket.
*
* @test
*/
public function getTokensShouldReturnCapacityAfterWaitingLongerThanRefillPeriod()
{
$rate = new Rate(1, Rate::SECOND);
$bucket = new TokenBucket(10, $rate, new SingleProcessStorage());
$bucket->bootstrap(0);
sleep(11);
$this->assertEquals(10, $bucket->getTokens());
}
