<?php
namespace Guzzle\Http;
use Guzzle\Common\Exception\RuntimeException;
/**
* EntityBody decorator that can cache previously read bytes from a sequentially read tstream
*/
class CachingEntityBody extends AbstractEntityBodyDecorator
{
/** @var EntityBody Remote stream used to actually pull data onto the buffer */
protected $remoteStream;
/** @var int The number of bytes to skip reading due to a write on the temporary buffer */
protected $skipReadBytes = 0;
/**
* We will treat the buffer object as the body of the entity body
* {@inheritdoc}
*/
public function __construct(EntityBodyInterface $body)
{
$this->remoteStream = $body;
$this->body = new EntityBody(fopen('php://temp', 'r+'));
}
/**
* Will give the contents of the buffer followed by the exhausted remote stream.
*
* Warning: Loads the entire stream into memory
*
* @return string
*/
public function __toString()
{
$pos = $this->ftell();
$this->rewind();
$str = '';
while (!$this->isConsumed()) {
$str .= $this->read(16384);
}
$this->seek($pos);
return $str;
}
public function getSize()
{
return max($this->body->getSize(), $this->remoteStream->getSize());
}
/**
* {@inheritdoc}
* @throws RuntimeException When seeking with SEEK_END or when seeking past the total size of the buffer stream
*/
public function seek($offset, $whence = SEEK_SET)
{
if ($whence == SEEK_SET) {
$byte = $offset;
} elseif ($whence == SEEK_CUR) {
$byte = $offset + $this->ftell();
} else {
throw new RuntimeException(__CLASS__ . ' supports only SEEK_SET and SEEK_CUR seek operations');
}
// You cannot skip ahead past where you've read from the remote stream
if ($byte > $this->body->getSize()) {
throw new RuntimeException(
"Cannot seek to byte {$byte} when the buffered stream only contains {$this->body->getSize()} bytes"
);
}
return $this->body->seek($byte);
}
public function rewind()
{
return $this->seek(0);
}
/**
* Does not support custom rewind functions
*
* @throws RuntimeException
*/
public function setRewindFunction($callable)
{
throw new RuntimeException(__CLASS__ . ' does not support custom stream rewind functions');
}
public function read($length)
{
// Perform a regular read on any previously read data from the buffer
$data = $this->body->read($length);
$remaining = $length - strlen($data);
// More data was requested so read from the remote stream
if ($remaining) {
// If data was written to the buffer in a position that would have been filled from the remote stream,
// then we must skip bytes on the remote stream to emulate overwriting bytes from that position. This
// mimics the behavior of other PHP stream wrappers.
$remoteData = $this->remoteStream->read($remaining + $this->skipReadBytes);
if ($this->skipReadBytes) {
$len = strlen($remoteData);
$remoteData = substr($remoteData, $this->skipReadBytes);
$this->skipReadBytes = max(0, $this->skipReadBytes - $len);
}
$data .= $remoteData;
$this->body->write($remoteData);
}
return $data;
}
public function write($string)
{
// When appending to the end of the currently read stream, you'll want to skip bytes from being read from
// the remote stream to emulate other stream wrappers. Basically replacing bytes of data of a fixed length.
$overflow = (strlen($string) + $this->ftell()) - $this->remoteStream->ftell();
if ($overflow > 0) {
$this->skipReadBytes += $overflow;
}
return $this->body->write($string);
}
/**
* {@inheritdoc}
* @link http://php.net/manual/en/function.fgets.php
*/
public function readLine($maxLength = null)
{
$buffer = '';
$size = 0;
while (!$this->isConsumed()) {
$byte = $this->read(1);
$buffer .= $byte;
// Break when a new line is found or the max length - 1 is reached
if ($byte == PHP_EOL || ++$size == $maxLength - 1) {
break;
}
}
return $buffer;
}
public function isConsumed()
{
return $this->body->isConsumed() && $this->remoteStream->isConsumed();
}
/**
* Close both the remote stream and buffer stream
*/
public function close()
{
return $this->remoteStream->close() && $this->body->close();
}
public function setStream($stream, $size = 0)
{
$this->remoteStream->setStream($stream, $size);
}
public function getContentType()
{
return $this->remoteStream->getContentType();
}
public function getContentEncoding()
{
return $this->remoteStream->getContentEncoding();
}
public function getMetaData($key = null)
{
return $this->remoteStream->getMetaData($key);
}
public function getStream()
{
return $this->remoteStream->getStream();
}
public function getWrapper()
{
return $this->remoteStream->getWrapper();
}
public function getWrapperData()
{
return $this->remoteStream->getWrapperData();
}
public function getStreamType()
{
return $this->remoteStream->getStreamType();
}
public function getUri()
{
return $this->remoteStream->getUri();
}
/**
* Always retrieve custom data from the remote stream
* {@inheritdoc}
*/
public function getCustomData($key)
{
return $this->remoteStream->getCustomData($key);
}
/**
* Always set custom data on the remote stream
* {@inheritdoc}
*/
public function setCustomData($key, $value)
{
$this->remoteStream->setCustomData($key, $value);
return $this;
}
}