/**
* {@inheritdoc}
*/
public function read($length)
{
$this->initialize();
if ($this->stream === null) {
return null;
}
$data = $this->stream->read($length);
if ($this->eof()) {
$this->close();
}
return $data;
}
public function read($length)
{
$readFromBuffer = $this->buffer->read($length);
if (strlen($readFromBuffer) === $length) {
return $readFromBuffer;
}
$remaining = $length - strlen($readFromBuffer);
// Calculate the approximate length required to read so that the base64 encoded stream does not have padding.
// base64 is calculated for blocks of 3 input characters resulting in 4 output characters.
// strlen(base64_encode($str)) ==> strlen($str) * 4 / 3
//
// This leads to:
//
// strlen($str) ==> strlen(base64_encode($str)) * 3 / 4
//
// Meaning, to read $length characters from the base64 encoded string, read 3/4 of $length from the original stream.
// $length is first rounded to the first larger number divisible by 4 since base64 encoded strings come in blocks of 4 characters.
$closestGroupLength = $remaining + (self::BASE64_BLOCK_SIZE - $remaining % self::BASE64_BLOCK_SIZE);
$read = $closestGroupLength * self::ORIGIN_BLOCK_SIZE / self::BASE64_BLOCK_SIZE;
$this->buffer->write(base64_encode($this->getStream()->read($read)));
return $readFromBuffer . $this->buffer->read($remaining);
}
/**
* {@inheritdoc}
*/
public function close()
{
$this->stream->close();
}
