1# Copyright 2012 Google Inc. All Rights Reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, 10# software distributed under the License is distributed on an 11# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 12# either express or implied. See the License for the specific 13# language governing permissions and limitations under the License. 14 15"""Google Cloud Storage specific Files API calls.""" 16 17 18 19 20 21__all__ = ['AuthorizationError', 22 'check_status', 23 'Error', 24 'FatalError', 25 'FileClosedError', 26 'ForbiddenError', 27 'InvalidRange', 28 'NotFoundError', 29 'ServerError', 30 'TimeoutError', 31 'TransientError', 32 ] 33 34import httplib 35 36 37class Error(Exception): 38 """Base error for all gcs operations. 39 40 Error can happen on GAE side or GCS server side. 41 For details on a particular GCS HTTP response code, see 42 https://developers.google.com/storage/docs/reference-status#standardcodes 43 """ 44 45 46class TransientError(Error): 47 """TransientError could be retried.""" 48 49 50class TimeoutError(TransientError): 51 """HTTP 408 timeout.""" 52 53 54class FatalError(Error): 55 """FatalError shouldn't be retried.""" 56 57 58class FileClosedError(FatalError): 59 """File is already closed. 60 61 This can happen when the upload has finished but 'write' is called on 62 a stale upload handle. 63 """ 64 65 66class NotFoundError(FatalError): 67 """HTTP 404 resource not found.""" 68 69 70class ForbiddenError(FatalError): 71 """HTTP 403 Forbidden. 72 73 While GCS replies with a 403 error for many reasons, the most common one 74 is due to bucket permission not correctly setup for your app to access. 75 """ 76 77 78class AuthorizationError(FatalError): 79 """HTTP 401 authentication required. 80 81 Unauthorized request has been received by GCS. 82 83 This error is mostly handled by GCS client. GCS client will request 84 a new access token and retry the request. 85 """ 86 87 88class InvalidRange(FatalError): 89 """HTTP 416 RequestRangeNotSatifiable.""" 90 91 92class ServerError(TransientError): 93 """HTTP >= 500 server side error.""" 94 95 96def check_status(status, expected, path, headers=None, 97 resp_headers=None, body=None, extras=None): 98 """Check HTTP response status is expected. 99 100 Args: 101 status: HTTP response status. int. 102 expected: a list of expected statuses. A list of ints. 103 path: filename or a path prefix. 104 headers: HTTP request headers. 105 resp_headers: HTTP response headers. 106 body: HTTP response body. 107 extras: extra info to be logged verbatim if error occurs. 108 109 Raises: 110 AuthorizationError: if authorization failed. 111 NotFoundError: if an object that's expected to exist doesn't. 112 TimeoutError: if HTTP request timed out. 113 ServerError: if server experienced some errors. 114 FatalError: if any other unexpected errors occurred. 115 """ 116 if status in expected: 117 return 118 119 msg = ('Expect status %r from Google Storage. But got status %d.\n' 120 'Path: %r.\n' 121 'Request headers: %r.\n' 122 'Response headers: %r.\n' 123 'Body: %r.\n' 124 'Extra info: %r.\n' % 125 (expected, status, path, headers, resp_headers, body, extras)) 126 127 if status == httplib.UNAUTHORIZED: 128 raise AuthorizationError(msg) 129 elif status == httplib.FORBIDDEN: 130 raise ForbiddenError(msg) 131 elif status == httplib.NOT_FOUND: 132 raise NotFoundError(msg) 133 elif status == httplib.REQUEST_TIMEOUT: 134 raise TimeoutError(msg) 135 elif status == httplib.REQUESTED_RANGE_NOT_SATISFIABLE: 136 raise InvalidRange(msg) 137 elif (status == httplib.OK and 308 in expected and 138 httplib.OK not in expected): 139 raise FileClosedError(msg) 140 elif status >= 500: 141 raise ServerError(msg) 142 else: 143 raise FatalError(msg) 144