Retry file uploads via SwiftService

When we introduced LengthWrapper, we neglected to make it resettable. As
a result, upload failures result in errors like:

    put_object(...) failure and no ability to reset contents for reupload.

Now, LengthWrappers will be resettable if their _readable has seek/tell.

Related-Change: I6c8bc1366dfb591a26d934a30cd21c9e6b9a04ce
Change-Id: I21f43f06e8c78b24d1fc081efedf2687942e042f
This commit is contained in:
Tim Burke 2015-09-23 10:42:43 -07:00
parent 81003b8d99
commit d4157ce5b5
4 changed files with 101 additions and 23 deletions

View File

@ -1546,10 +1546,12 @@ class Connection(object):
if self.retries > 0:
tell = getattr(contents, 'tell', None)
seek = getattr(contents, 'seek', None)
reset = getattr(contents, 'reset', None)
if tell and seek:
orig_pos = tell()
reset_func = lambda *a, **k: seek(orig_pos)
elif reset:
reset_func = reset
return self._retry(reset_func, put_object, container, obj, contents,
content_length=content_length, etag=etag,
chunk_size=chunk_size, content_type=content_type,

View File

@ -202,27 +202,36 @@ class LengthWrapper(object):
def __init__(self, readable, length, md5=False):
"""
:param readable: The filelike object to read from.
:param length: The maximum amount of content to that can be read from
:param length: The maximum amount of content that can be read from
the filelike object before it is simulated to be
empty.
:param md5: Flag to enable calculating the MD5 of the content
as it is read.
"""
self.md5sum = hashlib.md5() if md5 else NoopMD5()
self._md5 = md5
self._reset_md5()
self._length = self._remaining = length
self._readable = readable
self._can_reset = all(hasattr(readable, attr)
for attr in ('seek', 'tell'))
if self._can_reset:
self._start = readable.tell()
def __len__(self):
return self._length
def _reset_md5(self):
self.md5sum = hashlib.md5() if self._md5 else NoopMD5()
def get_md5sum(self):
return self.md5sum.hexdigest()
def read(self, *args, **kwargs):
def read(self, size=-1):
if self._remaining <= 0:
return ''
chunk = self._readable.read(*args, **kwargs)[:self._remaining]
to_read = self._remaining if size < 0 else min(size, self._remaining)
chunk = self._readable.read(to_read)
self._remaining -= len(chunk)
try:
@ -232,6 +241,21 @@ class LengthWrapper(object):
return chunk
@property
def reset(self):
if self._can_reset:
return self._reset
raise AttributeError("%r object has no attribute 'reset'" %
type(self).__name__)
def _reset(self, *args, **kwargs):
if not self._can_reset:
raise TypeError('%r object cannot be reset; needs both seek and '
'tell methods' % type(self._readable).__name__)
self._readable.seek(self._start)
self._reset_md5()
self._remaining = self._length
def iter_wrapper(iterable):
for chunk in iterable:

View File

@ -17,6 +17,7 @@ import logging
import mock
import six
import socket
import string
import testtools
import warnings
import tempfile
@ -1774,23 +1775,24 @@ class TestConnection(MockHttpTest):
class LocalContents(object):
def __init__(self, tell_value=0):
self.already_read = False
self.data = six.BytesIO(string.ascii_letters.encode() * 10)
self.data.seek(tell_value)
self.reads = []
self.seeks = []
self.tell_value = tell_value
self.tells = []
def tell(self):
return self.tell_value
self.tells.append(self.data.tell())
return self.tells[-1]
def seek(self, position):
self.seeks.append(position)
self.already_read = False
def seek(self, position, mode=0):
self.seeks.append((position, mode))
self.data.seek(position, mode)
def read(self, size=-1):
if self.already_read:
return ''
else:
self.already_read = True
return 'abcdef'
read_data = self.data.read(size)
self.reads.append((size, read_data))
return read_data
class LocalConnection(object):
@ -1801,7 +1803,7 @@ class TestConnection(MockHttpTest):
self.port = parsed_url.netloc
def putrequest(self, *args, **kwargs):
self.send()
self.send('PUT', *args, **kwargs)
def putheader(self, *args, **kwargs):
return
@ -1810,6 +1812,13 @@ class TestConnection(MockHttpTest):
return
def send(self, *args, **kwargs):
data = kwargs.get('data')
if data is not None:
if hasattr(data, 'read'):
data.read()
else:
for datum in data:
pass
raise socket.error('oops')
def request(self, *args, **kwargs):
@ -1844,7 +1853,12 @@ class TestConnection(MockHttpTest):
conn.put_object('c', 'o', contents)
except socket.error as err:
exc = err
self.assertEqual(contents.seeks, [0])
self.assertEqual(contents.tells, [0])
self.assertEqual(contents.seeks, [(0, 0)])
# four reads: two in the initial pass, two in the retry
self.assertEqual(4, len(contents.reads))
self.assertEqual((65536, b''), contents.reads[1])
self.assertEqual((65536, b''), contents.reads[3])
self.assertEqual(str(exc), 'oops')
contents = LocalContents(tell_value=123)
@ -1853,9 +1867,29 @@ class TestConnection(MockHttpTest):
conn.put_object('c', 'o', contents)
except socket.error as err:
exc = err
self.assertEqual(contents.seeks, [123])
self.assertEqual(contents.tells, [123])
self.assertEqual(contents.seeks, [(123, 0)])
# four reads: two in the initial pass, two in the retry
self.assertEqual(4, len(contents.reads))
self.assertEqual((65536, b''), contents.reads[1])
self.assertEqual((65536, b''), contents.reads[3])
self.assertEqual(str(exc), 'oops')
contents = LocalContents(tell_value=123)
wrapped_contents = swiftclient.utils.LengthWrapper(
contents, 6, md5=True)
exc = None
try:
conn.put_object('c', 'o', wrapped_contents)
except socket.error as err:
exc = err
self.assertEqual(contents.tells, [123])
self.assertEqual(contents.seeks, [(123, 0)])
self.assertEqual(contents.reads, [(6, b'tuvwxy')] * 2)
self.assertEqual(str(exc), 'oops')
self.assertEqual(md5(b'tuvwxy').hexdigest(),
wrapped_contents.get_md5sum())
contents = LocalContents()
contents.tell = None
exc = None

View File

@ -219,9 +219,10 @@ class TestReadableToIterable(testtools.TestCase):
class TestLengthWrapper(testtools.TestCase):
def test_stringio(self):
contents = six.StringIO(u'a' * 100)
contents = six.StringIO(u'a' * 50 + u'b' * 50)
contents.seek(22)
data = u.LengthWrapper(contents, 42, True)
s = u'a' * 42
s = u'a' * 28 + u'b' * 14
read_data = u''.join(iter(data.read, ''))
self.assertEqual(42, len(data))
@ -229,10 +230,19 @@ class TestLengthWrapper(testtools.TestCase):
self.assertEqual(s, read_data)
self.assertEqual(md5(s.encode()).hexdigest(), data.get_md5sum())
data.reset()
self.assertEqual(md5().hexdigest(), data.get_md5sum())
read_data = u''.join(iter(data.read, ''))
self.assertEqual(42, len(read_data))
self.assertEqual(s, read_data)
self.assertEqual(md5(s.encode()).hexdigest(), data.get_md5sum())
def test_bytesio(self):
contents = six.BytesIO(b'a' * 100)
contents = six.BytesIO(b'a' * 50 + b'b' * 50)
contents.seek(22)
data = u.LengthWrapper(contents, 42, True)
s = b'a' * 42
s = b'a' * 28 + b'b' * 14
read_data = b''.join(iter(data.read, ''))
self.assertEqual(42, len(data))
@ -272,3 +282,11 @@ class TestLengthWrapper(testtools.TestCase):
self.assertEqual(segment_length, len(read_data))
self.assertEqual(s, read_data)
self.assertEqual(md5(s).hexdigest(), data.get_md5sum())
data.reset()
self.assertEqual(md5().hexdigest(), data.get_md5sum())
read_data = b''.join(iter(data.read, ''))
self.assertEqual(segment_length, len(data))
self.assertEqual(segment_length, len(read_data))
self.assertEqual(s, read_data)
self.assertEqual(md5(s).hexdigest(), data.get_md5sum())