<?php
namespace Guzzle\Http;
use Guzzle\Stream\StreamInterface;
/**
* EntityBody decorator used to return only a subset of an entity body
*/
class ReadLimitEntityBody extends AbstractEntityBodyDecorator
{
/** @var int Limit the number of bytes that can be read */
protected $limit;
/** @var int Offset to start reading from */
protected $offset;
/**
* @param EntityBodyInterface $body Body to wrap
* @param int $limit Total number of bytes to allow to be read from the stream
* @param int $offset Position to seek to before reading (only works on seekable streams)
*/
public function __construct(EntityBodyInterface $body, $limit, $offset = 0)
{
parent::__construct($body);
$this->setLimit($limit)->setOffset($offset);
}
/**
* Returns only a subset of the decorated entity body when cast as a string
* {@inheritdoc}
*/
public function __toString()
{
if (!$this->body->isReadable() ||
(!$this->body->isSeekable() && $this->body->isConsumed())
) {
return '';
}
$originalPos = $this->body->ftell();
$this->body->seek($this->offset);
$data = '';
while (!$this->feof()) {
$data .= $this->read(1048576);
}
$this->body->seek($originalPos);
return (string) $data ?: '';
}
public function isConsumed()
{
return $this->body->isConsumed() ||
($this->body->ftell() >= $this->offset + $this->limit);
}
/**
* Returns the Content-Length of the limited subset of data
* {@inheritdoc}
*/
public function getContentLength()
{
$length = $this->body->getContentLength();
return $length === false
? $this->limit
: min($this->limit, min($length, $this->offset + $this->limit) - $this->offset);
}
/**
* Allow for a bounded seek on the read limited entity body
* {@inheritdoc}
*/
public function seek($offset, $whence = SEEK_SET)
{
return $whence === SEEK_SET
? $this->body->seek(max($this->offset, min($this->offset + $this->limit, $offset)))
: false;
}
/**
* Set the offset to start limiting from
*
* @param int $offset Offset to seek to and begin byte limiting from
*
* @return self
*/
public function setOffset($offset)
{
$this->body->seek($offset);
$this->offset = $offset;
return $this;
}
/**
* Set the limit of bytes that the decorator allows to be read from the stream
*
* @param int $limit Total number of bytes to allow to be read from the stream
*
* @return self
*/
public function setLimit($limit)
{
$this->limit = $limit;
return $this;
}
public function read($length)
{
// Check if the current position is less than the total allowed bytes + original offset
$remaining = ($this->offset + $this->limit) - $this->body->ftell();
if ($remaining > 0) {
// Only return the amount of requested data, ensuring that the byte limit is not exceeded
return $this->body->read(min($remaining, $length));
} else {
return false;
}
}
}