Stop holding on to sys.exc_info tuples quite so much

This used to be necessary on older eventlet, or you'd get TypeErrors
when you went to reraise. Following eventlet 0.13.0, however, it's just
extra code.

For the original eventlet issue, see
https://web.archive.org/web/20140823005223/https://bitbucket.org/eventlet/eventlet/issue/149/yield-in-except-clause-with-wilcard-raise

Change-Id: I19ad0968a82827bdd4ef75fde9ed51f193627d6e
Related-Bug: 1181146

swift/common/internal_client.py

@@ -221,7 +221,7 @@ class InternalClient(object):
             raise UnexpectedResponse(msg, resp)
         if exc_type:
             # To make pep8 tool happy, in place of raise t, v, tb:
-            six.reraise(exc_type(*exc_value.args), None, exc_traceback)
+            six.reraise(exc_type, exc_value, exc_traceback)
 
     def _get_metadata(
             self, path, metadata_prefix='', acceptable_statuses=(2,),

swift/common/middleware/proxy_logging.py

@@ -71,10 +71,8 @@ if this is a middleware subrequest or not. A log processor calculating
 bandwidth usage will want to only sum up logs with no swift.source.
 """
 
-import sys
 import time
 
-import six
 from six.moves.urllib.parse import quote
 from swift.common.swob import Request
 from swift.common.utils import (get_logger, get_remote_client,
@@ -333,13 +331,12 @@ class ProxyLoggingMiddleware(object):
         try:
             iterable = self.app(env, my_start_response)
         except Exception:
-            exc_type, exc_value, exc_traceback = sys.exc_info()
             req = Request(env)
             status_int = status_int_for_logging(start_status=500)
             self.log_request(
                 req, status_int, input_proxy.bytes_received, 0, start_time,
                 time.time())
-            six.reraise(exc_type, exc_value, exc_traceback)
+            raise
         else:
             return iter_response(iterable)
 

swift/common/middleware/s3api/acl_handlers.py

@@ -49,8 +49,6 @@ Example::
   the end of method.
 
 """
-import sys
-
 from swift.common.middleware.s3api.subresource import ACL, Owner, encode_acl
 from swift.common.middleware.s3api.s3response import MissingSecurityHeader, \
     MalformedACLError, UnexpectedContent
@@ -168,9 +166,8 @@ class BaseAclHandler(object):
             except(XMLSyntaxError, DocumentInvalid):
                 raise MalformedACLError()
             except Exception as e:
-                exc_type, exc_value, exc_traceback = sys.exc_info()
                 self.logger.error(e)
-                raise exc_type, exc_value, exc_traceback
+                raise
         else:
             if body:
                 # Specifying grant with both header and xml is not allowed.

swift/common/middleware/s3api/controllers/bucket.py

@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import sys
 from base64 import standard_b64encode as b64encode
 from base64 import standard_b64decode as b64decode
 
@@ -218,9 +217,8 @@ class BucketController(Controller):
             except (XMLSyntaxError, DocumentInvalid):
                 raise MalformedXML()
             except Exception as e:
-                exc_type, exc_value, exc_traceback = sys.exc_info()
                 self.logger.error(e)
-                raise exc_type, exc_value, exc_traceback
+                raise
 
             if location != self.conf.location:
                 # s3api cannot support multiple regions currently.

swift/common/middleware/s3api/controllers/multi_delete.py

@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import sys
-
 from swift.common.utils import public
 
 from swift.common.middleware.s3api.controllers.base import Controller, \
@@ -85,9 +83,8 @@ class MultiObjectDeleteController(Controller):
         except ErrorResponse:
             raise
         except Exception as e:
-            exc_type, exc_value, exc_traceback = sys.exc_info()
             self.logger.error(e)
-            raise exc_type, exc_value, exc_traceback
+            raise
 
         elem = Element('DeleteResult')
 

swift/common/middleware/s3api/controllers/multi_upload.py

@@ -61,7 +61,6 @@ Static Large Object when the multipart upload is completed.
 
 import os
 import re
-import sys
 
 from swift.common.swob import Range
 from swift.common.utils import json, public
@@ -605,9 +604,8 @@ class UploadController(Controller):
         except ErrorResponse:
             raise
         except Exception as e:
-            exc_type, exc_value, exc_traceback = sys.exc_info()
             self.logger.error(e)
-            raise exc_type, exc_value, exc_traceback
+            raise
 
         # Check the size of each segment except the last and make sure they are
         # all more than the minimum upload chunk size

swift/common/middleware/s3api/controllers/obj.py

@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import sys
-
 from swift.common.http import HTTP_OK, HTTP_PARTIAL_CONTENT, HTTP_NO_CONTENT
 from swift.common.swob import Range, content_range_header_value
 from swift.common.utils import public
@@ -144,7 +142,6 @@ class ObjectController(Controller):
                 resp.body = ''
         except NoSuchKey:
             # expect to raise NoSuchBucket when the bucket doesn't exist
-            exc_type, exc_value, exc_traceback = sys.exc_info()
             req.get_container_info(self.app)
-            raise exc_type, exc_value, exc_traceback
+            raise
         return resp

swift/common/middleware/s3api/etree.py

@@ -18,7 +18,6 @@ from urllib import quote
 from copy import deepcopy
 from pkg_resources import resource_stream  # pylint: disable-msg=E0611
 import six
-import sys
 
 from swift.common.utils import get_logger
 from swift.common.middleware.s3api.exception import S3Exception
@@ -76,10 +75,9 @@ def fromstring(text, root_tag=None, logger=None):
                 lxml.etree.RelaxNG(file=rng).assertValid(elem)
         except IOError as e:
             # Probably, the schema file doesn't exist.
-            exc_type, exc_value, exc_traceback = sys.exc_info()
             logger = logger or get_logger({}, log_route='s3api')
             logger.error(e)
-            raise exc_type, exc_value, exc_traceback
+            raise
         except lxml.etree.DocumentInvalid as e:
             if logger:
                 logger.debug(e)

swift/proxy/controllers/base.py

@@ -973,7 +973,7 @@ class ResumingGetter(object):
                     except ChunkReadTimeout:
                         exc_type, exc_value, exc_traceback = exc_info()
                         if self.newest or self.server_type != 'Object':
-                            six.reraise(exc_type, exc_value, exc_traceback)
+                            raise
                         try:
                             self.fast_forward(self.bytes_used_from_backend)
                         except (HTTPException, ValueError):
@@ -1091,20 +1091,18 @@ class ResumingGetter(object):
                 self.app.client_timeout)
             self.app.logger.increment('client_timeouts')
         except GeneratorExit:
-            exc_type, exc_value, exc_traceback = exc_info()
             warn = True
-            try:
-                req_range = Range(self.backend_headers['Range'])
-            except ValueError:
-                req_range = None
-            if req_range and len(req_range.ranges) == 1:
-                begin, end = req_range.ranges[0]
-                if end is not None and begin is not None:
-                    if end - begin + 1 == self.bytes_used_from_backend:
-                        warn = False
+            req_range = self.backend_headers['Range']
+            if req_range:
+                req_range = Range(req_range)
+                if len(req_range.ranges) == 1:
+                    begin, end = req_range.ranges[0]
+                    if end is not None and begin is not None:
+                        if end - begin + 1 == self.bytes_used_from_backend:
+                            warn = False
             if not req.environ.get('swift.non_client_disconnect') and warn:
                 self.app.logger.warning(_('Client disconnected on read'))
-            six.reraise(exc_type, exc_value, exc_traceback)
+            raise
         except Exception:
             self.app.logger.exception(_('Trying to send to client'))
             raise