<?php
namespace GuzzleHttp\Stream;

/**
* Stream decorator that begins dropping data once the size of the underlying
* stream becomes too full.
*/
class DroppingStream implements StreamInterface
{
use StreamDecoratorTrait;

private $maxLength;

/**
* @param StreamInterface $stream Underlying stream to decorate.
* @param int $maxLength Maximum size before dropping data.
*/
public function __construct(StreamInterface $stream, $maxLength)
{
$this->stream = $stream;
$this->maxLength = $maxLength;
}

public function write($string)
{
$diff = $this->maxLength - $this->stream->getSize();

// Begin returning false when the underlying stream is too large.
if ($diff <= 0) {
return false;
}

// Write the stream or a subset of the stream if needed.
if (strlen($string) < $diff) {
return $this->stream->write($string);
}

$this->stream->write(substr($string, 0, $diff));

return false;
}
}