/**
* Append another chunk data to a previously-started chunked upload session.
*
* @param string $uploadId
* The unique identifier for the chunked upload session. This is obtained via
* {@link chunkedUploadStart}.
*
* @param int $byteOffset
* The number of bytes you think you've already uploaded to the given chunked upload
* session. The server will append the new chunk of data after that point.
*
* @param string $data
* The data to append to the existing chunked upload session.
*
* @return int|bool
* If <code>false</code>, it means the server didn't know about the given
* <code>$uploadId</code>. This may be because the chunked upload session has expired
* (they last around 24 hours).
* If <code>true</code>, the chunk was successfully uploaded. If an integer, it means
* you and the server don't agree on the current <code>$byteOffset</code>. The returned
* integer is the server's internal byte offset for the chunked upload session. You need
* to adjust your input to match.
*
* @throws Exception
*/
function chunkedUploadContinue($uploadId, $byteOffset, $data)
{
Checker::argStringNonEmpty("uploadId", $uploadId);
Checker::argNat("byteOffset", $byteOffset);
Checker::argString("data", $data);
$response = $this->_chunkedUpload(array("upload_id" => $uploadId, "offset" => $byteOffset), $data);
if ($response->statusCode === 404) {
// The server doesn't know our upload ID. Maybe it expired?
return false;
}
$correction = self::_chunkedUploadCheckForOffsetCorrection($response);
if ($correction !== null) {
list($correctedUploadId, $correctedByteOffset) = $correction;
if ($correctedUploadId !== $uploadId) {
throw new Exception_BadResponse("Corrective 400 upload_id mismatch: us=" . self::q($uploadId) . " server=" . self::q($correctedUploadId));
}
if ($correctedByteOffset === $byteOffset) {
throw new Exception_BadResponse("Corrective 400 offset is the same as ours: {$byteOffset}");
}
return $correctedByteOffset;
}
if ($response->statusCode !== 200) {
throw RequestUtil::unexpectedStatus($response);
}
list($retUploadId, $retByteOffset) = self::_chunkedUploadParse200Response($response->body);
$nextByteOffset = $byteOffset + strlen($data);
if ($uploadId !== $retUploadId) {
throw new Exception_BadResponse("upload_id mismatch: us=" . self::q($uploadId) . ", server=" . self::q($uploadId));
}
if ($nextByteOffset !== $retByteOffset) {
throw new Exception_BadResponse("next-offset mismatch: us={$nextByteOffset}, server={$retByteOffset}");
}
return true;
}
/**
* @param int $maxRetries
* The number of times to retry it the action if it fails with one of the transient
* API errors. A value of 1 means we'll try the action once and if it fails, we
* will retry once.
*
* @param callable $action
* The the action you want to retry.
*
* @return mixed
* Whatever is returned by the $action callable.
*/
static function runWithRetry($maxRetries, $action)
{
Checker::argNat("maxRetries", $maxRetries);
$retryDelay = 1;
$numRetries = 0;
while (true) {
try {
return $action();
} catch (Exception_NetworkIO $ex) {
$savedEx = $ex;
} catch (Exception_ServerError $ex) {
$savedEx = $ex;
} catch (Exception_RetryLater $ex) {
$savedEx = $ex;
}
// We maxed out our retries. Propagate the last exception we got.
if ($numRetries >= $maxRetries) {
throw $savedEx;
}
$numRetries++;
sleep($retryDelay);
$retryDelay *= 2;
// Exponential back-off.
}
throw new \RuntimeException("unreachable");
}
