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Specify VersionId when possible on multipart downloads #254

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Specify VersionId when possible on multipart downloads #254

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50 changes: 34 additions & 16 deletions s3transfer/__init__.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -533,6 +533,11 @@ def __init__(

def download_file(
self, bucket, key, filename, object_size, extra_args, callback=None
):
self.download_versioned_file(bucket, key, filename, object_size, None, extra_args, callback=callback)

def download_versioned_file(
self, bucket, key, filename, object_size, object_version, extra_args, callback=None
):
with self._executor_cls(max_workers=2) as controller:
# 1 thread for the future that manages the uploading of files
Expand All @@ -543,6 +548,7 @@ def download_file(
key,
filename,
object_size,
object_version,
callback,
)
parts_future = controller.submit(download_parts_handler)
Expand All @@ -563,7 +569,7 @@ def _process_future_results(self, futures):
future.result()

def _download_file_as_future(
self, bucket, key, filename, object_size, callback
self, bucket, key, filename, object_size, object_version, callback
):
part_size = self._config.multipart_chunksize
num_parts = int(math.ceil(object_size / float(part_size)))
Expand All @@ -573,6 +579,7 @@ def _download_file_as_future(
bucket,
key,
filename,
object_version,
part_size,
num_parts,
callback,
Expand All @@ -593,7 +600,7 @@ def _calculate_range_param(self, part_size, part_index, num_parts):
return range_param

def _download_range(
self, bucket, key, filename, part_size, num_parts, callback, part_index
self, bucket, key, filename, object_version, part_size, num_parts, callback, part_index
):
try:
range_param = self._calculate_range_param(
Expand All @@ -605,9 +612,10 @@ def _download_range(
for i in range(max_attempts):
try:
logger.debug("Making get_object call.")
response = self._client.get_object(
Bucket=bucket, Key=key, Range=range_param
)
kwargs = {'Bucket': bucket, 'Key': key, 'Range': range_param}
if object_version is not None:
kwargs['VersionId'] = object_version
response = self._client.get_object(**kwargs)
streaming_body = StreamReaderProgress(
response['Body'], callback
)
Expand Down Expand Up @@ -781,11 +789,23 @@ def download_file(
if extra_args is None:
extra_args = {}
self._validate_all_known_args(extra_args, self.ALLOWED_DOWNLOAD_ARGS)
object_size = self._object_size(bucket, key, extra_args)
object_meta = self._object_meta(bucket, key, extra_args)
object_size = object_meta['ContentLength']

# If the latest version of the file changes during a multipart download and we make
# multiple concurrent ranged downloads, then each download may see a different version.
# To avoid this, we specify a common version for all. If the bucket does not have
# version, then there is nothing that can be done, and we specify no version.
object_version = object_meta.get('VersionId')
if object_version is not None:
logger.debug("Using version ID %s for %s/%s", object_version, bucket, key)
else:
logger.debug("Not using version ID for %s/%s", bucket, key)

temp_filename = filename + os.extsep + random_file_extension()
try:
self._download_file(
bucket, key, temp_filename, object_size, extra_args, callback
bucket, key, temp_filename, object_size, object_version, extra_args, callback
)
except Exception:
logger.debug(
Expand All @@ -800,11 +820,11 @@ def download_file(
self._osutil.rename_file(temp_filename, filename)

def _download_file(
self, bucket, key, filename, object_size, extra_args, callback
self, bucket, key, filename, object_size, object_version, extra_args, callback
):
if object_size >= self._config.multipart_threshold:
self._ranged_download(
bucket, key, filename, object_size, extra_args, callback
bucket, key, filename, object_size, object_version, extra_args, callback
)
else:
self._get_object(bucket, key, filename, extra_args, callback)
Expand All @@ -818,13 +838,13 @@ def _validate_all_known_args(self, actual, allowed):
)

def _ranged_download(
self, bucket, key, filename, object_size, extra_args, callback
self, bucket, key, filename, object_size, object_version, extra_args, callback
):
downloader = MultipartDownloader(
self._client, self._config, self._osutil
)
downloader.download_file(
bucket, key, filename, object_size, extra_args, callback
downloader.download_versioned_file(
bucket, key, filename, object_size, object_version, extra_args, callback
)

def _get_object(self, bucket, key, filename, extra_args, callback):
Expand Down Expand Up @@ -865,10 +885,8 @@ def _do_get_object(self, bucket, key, filename, extra_args, callback):
for chunk in iter(lambda: streaming_body.read(8192), b''):
f.write(chunk)

def _object_size(self, bucket, key, extra_args):
return self._client.head_object(Bucket=bucket, Key=key, **extra_args)[
'ContentLength'
]
def _object_meta(self, bucket, key, extra_args):
return self._client.head_object(Bucket=bucket, Key=key, **extra_args)

def _multipart_upload(self, filename, bucket, key, callback, extra_args):
uploader = MultipartUploader(self._client, self._config, self._osutil)
Expand Down
38 changes: 37 additions & 1 deletion tests/unit/test_s3transfer.py
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Original file line number Diff line number Diff line change
Expand Up @@ -382,6 +382,7 @@ class TestMultipartDownloader(unittest.TestCase):

def test_multipart_download_uses_correct_client_calls(self):
client = mock.Mock()
version_id = '123'
response_body = b'foobarbaz'
client.get_object.return_value = {'Body': BytesIO(response_body)}

Expand All @@ -396,6 +397,14 @@ def test_multipart_download_uses_correct_client_calls(self):
Range='bytes=0-', Bucket='bucket', Key='key'
)

downloader.download_versioned_file(
'bucket', 'key', 'filename', len(response_body), version_id, {}
)

client.get_object.assert_called_with(
Range='bytes=0-', Bucket='bucket', Key='key', VersionId=version_id
)

def test_multipart_download_with_multiple_parts(self):
client = mock.Mock()
response_body = b'foobarbaz'
Expand Down Expand Up @@ -608,12 +617,39 @@ def test_uses_multipart_download_when_over_threshold(self):
'bucket', 'key', 'filename', callback=callback
)

downloader.return_value.download_file.assert_called_with(
downloader.return_value.download_versioned_file.assert_called_with(
# Note how we're downloading to a temporary random file.
'bucket',
'key',
'filename.RANDOM',
over_multipart_threshold,
None,
{},
callback,
)

def test_multipart_download_uses_version(self):
with mock.patch('s3transfer.MultipartDownloader') as downloader:
osutil = InMemoryOSLayer({})
over_multipart_threshold = 100 * 1024 * 1024
version_id = 'version-id'
transfer = S3Transfer(self.client, osutil=osutil)
callback = mock.sentinel.CALLBACK
self.client.head_object.return_value = {
'ContentLength': over_multipart_threshold,
'VersionId': version_id,
}
transfer.download_file(
'bucket', 'key', 'filename', callback=callback
)

downloader.return_value.download_versioned_file.assert_called_with(
# Note how we're downloading to a temporary random file.
'bucket',
'key',
'filename.RANDOM',
over_multipart_threshold,
version_id,
{},
callback,
)
Expand Down