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721 lines
28 KiB
721 lines
28 KiB
# Copyright 2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"). You
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# may not use this file except in compliance with the License. A copy of
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# the License is located at
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#
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# http://aws.amazon.com/apache2.0/
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#
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# or in the "license" file accompanying this file. This file is
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# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
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# ANY KIND, either express or implied. See the License for the specific
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# language governing permissions and limitations under the License.
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import logging
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import os
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import socket
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import math
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import threading
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import heapq
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from botocore.compat import six
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from botocore.exceptions import IncompleteReadError
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from botocore.vendored.requests.packages.urllib3.exceptions import \
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ReadTimeoutError
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from s3transfer.compat import SOCKET_ERROR
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from s3transfer.compat import seekable
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from s3transfer.exceptions import RetriesExceededError
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from s3transfer.futures import IN_MEMORY_DOWNLOAD_TAG
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from s3transfer.utils import random_file_extension
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from s3transfer.utils import get_callbacks
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from s3transfer.utils import invoke_progress_callbacks
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from s3transfer.utils import calculate_range_parameter
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from s3transfer.utils import FunctionContainer
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from s3transfer.utils import CountCallbackInvoker
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from s3transfer.utils import StreamReaderProgress
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from s3transfer.utils import DeferredOpenFile
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from s3transfer.tasks import Task
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from s3transfer.tasks import SubmissionTask
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logger = logging.getLogger(__name__)
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S3_RETRYABLE_ERRORS = (
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socket.timeout, SOCKET_ERROR, ReadTimeoutError, IncompleteReadError
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)
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class DownloadOutputManager(object):
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"""Base manager class for handling various types of files for downloads
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This class is typically used for the DownloadSubmissionTask class to help
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determine the following:
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* Provides the fileobj to write to downloads to
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* Get a task to complete once everything downloaded has been written
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The answers/implementations differ for the various types of file outputs
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that may be accepted. All implementations must subclass and override
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public methods from this class.
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"""
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def __init__(self, osutil, transfer_coordinator, io_executor):
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self._osutil = osutil
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self._transfer_coordinator = transfer_coordinator
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self._io_executor = io_executor
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@classmethod
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def is_compatible(cls, download_target, osutil):
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"""Determines if the target for the download is compatible with manager
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:param download_target: The target for which the upload will write
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data to.
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:param osutil: The os utility to be used for the transfer
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:returns: True if the manager can handle the type of target specified
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otherwise returns False.
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"""
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raise NotImplementedError('must implement is_compatible()')
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def get_download_task_tag(self):
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"""Get the tag (if any) to associate all GetObjectTasks
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:rtype: s3transfer.futures.TaskTag
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:returns: The tag to associate all GetObjectTasks with
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"""
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return None
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def get_fileobj_for_io_writes(self, transfer_future):
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"""Get file-like object to use for io writes in the io executor
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:type transfer_future: s3transfer.futures.TransferFuture
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:param transfer_future: The future associated with upload request
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returns: A file-like object to write to
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"""
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raise NotImplementedError('must implement get_fileobj_for_io_writes()')
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def queue_file_io_task(self, fileobj, data, offset):
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"""Queue IO write for submission to the IO executor.
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This method accepts an IO executor and information about the
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downloaded data, and handles submitting this to the IO executor.
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This method may defer submission to the IO executor if necessary.
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"""
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self._transfer_coordinator.submit(
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self._io_executor,
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self.get_io_write_task(fileobj, data, offset)
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)
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def get_io_write_task(self, fileobj, data, offset):
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"""Get an IO write task for the requested set of data
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This task can be ran immediately or be submitted to the IO executor
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for it to run.
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:type fileobj: file-like object
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:param fileobj: The file-like object to write to
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:type data: bytes
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:param data: The data to write out
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:type offset: integer
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:param offset: The offset to write the data to in the file-like object
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:returns: An IO task to be used to write data to a file-like object
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"""
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return IOWriteTask(
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self._transfer_coordinator,
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main_kwargs={
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'fileobj': fileobj,
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'data': data,
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'offset': offset,
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}
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)
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def get_final_io_task(self):
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"""Get the final io task to complete the download
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This is needed because based on the architecture of the TransferManager
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the final tasks will be sent to the IO executor, but the executor
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needs a final task for it to signal that the transfer is done and
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all done callbacks can be run.
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:rtype: s3transfer.tasks.Task
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:returns: A final task to completed in the io executor
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"""
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raise NotImplementedError(
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'must implement get_final_io_task()')
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def _get_fileobj_from_filename(self, filename):
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f = DeferredOpenFile(
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filename, mode='wb', open_function=self._osutil.open)
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# Make sure the file gets closed and we remove the temporary file
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# if anything goes wrong during the process.
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self._transfer_coordinator.add_failure_cleanup(f.close)
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return f
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class DownloadFilenameOutputManager(DownloadOutputManager):
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def __init__(self, osutil, transfer_coordinator, io_executor):
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super(DownloadFilenameOutputManager, self).__init__(
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osutil, transfer_coordinator, io_executor)
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self._final_filename = None
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self._temp_filename = None
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self._temp_fileobj = None
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@classmethod
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def is_compatible(cls, download_target, osutil):
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return isinstance(download_target, six.string_types)
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def get_fileobj_for_io_writes(self, transfer_future):
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fileobj = transfer_future.meta.call_args.fileobj
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self._final_filename = fileobj
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self._temp_filename = fileobj + os.extsep + random_file_extension()
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self._temp_fileobj = self._get_temp_fileobj()
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return self._temp_fileobj
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def get_final_io_task(self):
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# A task to rename the file from the temporary file to its final
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# location is needed. This should be the last task needed to complete
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# the download.
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return IORenameFileTask(
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transfer_coordinator=self._transfer_coordinator,
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main_kwargs={
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'fileobj': self._temp_fileobj,
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'final_filename': self._final_filename,
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'osutil': self._osutil
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},
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is_final=True
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)
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def _get_temp_fileobj(self):
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f = self._get_fileobj_from_filename(self._temp_filename)
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self._transfer_coordinator.add_failure_cleanup(
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self._osutil.remove_file, self._temp_filename)
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return f
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class DownloadSeekableOutputManager(DownloadOutputManager):
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@classmethod
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def is_compatible(cls, download_target, osutil):
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return seekable(download_target)
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def get_fileobj_for_io_writes(self, transfer_future):
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# Return the fileobj provided to the future.
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return transfer_future.meta.call_args.fileobj
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def get_final_io_task(self):
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# This task will serve the purpose of signaling when all of the io
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# writes have finished so done callbacks can be called.
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return CompleteDownloadNOOPTask(
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transfer_coordinator=self._transfer_coordinator)
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class DownloadNonSeekableOutputManager(DownloadOutputManager):
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def __init__(self, osutil, transfer_coordinator, io_executor,
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defer_queue=None):
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super(DownloadNonSeekableOutputManager, self).__init__(
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osutil, transfer_coordinator, io_executor)
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if defer_queue is None:
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defer_queue = DeferQueue()
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self._defer_queue = defer_queue
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self._io_submit_lock = threading.Lock()
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@classmethod
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def is_compatible(cls, download_target, osutil):
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return hasattr(download_target, 'write')
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def get_download_task_tag(self):
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return IN_MEMORY_DOWNLOAD_TAG
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def get_fileobj_for_io_writes(self, transfer_future):
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return transfer_future.meta.call_args.fileobj
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def get_final_io_task(self):
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return CompleteDownloadNOOPTask(
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transfer_coordinator=self._transfer_coordinator)
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def queue_file_io_task(self, fileobj, data, offset):
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with self._io_submit_lock:
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writes = self._defer_queue.request_writes(offset, data)
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for write in writes:
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data = write['data']
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logger.debug("Queueing IO offset %s for fileobj: %s",
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write['offset'], fileobj)
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super(
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DownloadNonSeekableOutputManager, self).queue_file_io_task(
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fileobj, data, offset)
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def get_io_write_task(self, fileobj, data, offset):
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return IOStreamingWriteTask(
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self._transfer_coordinator,
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main_kwargs={
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'fileobj': fileobj,
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'data': data,
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}
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)
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class DownloadSpecialFilenameOutputManager(DownloadNonSeekableOutputManager):
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def __init__(self, osutil, transfer_coordinator, io_executor,
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defer_queue=None):
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super(DownloadSpecialFilenameOutputManager, self).__init__(
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osutil, transfer_coordinator, io_executor, defer_queue)
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self._fileobj = None
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@classmethod
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def is_compatible(cls, download_target, osutil):
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return isinstance(download_target, six.string_types) and \
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osutil.is_special_file(download_target)
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def get_fileobj_for_io_writes(self, transfer_future):
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filename = transfer_future.meta.call_args.fileobj
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self._fileobj = self._get_fileobj_from_filename(filename)
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return self._fileobj
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def get_final_io_task(self):
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# Make sure the file gets closed once the transfer is done.
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return IOCloseTask(
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transfer_coordinator=self._transfer_coordinator,
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is_final=True,
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main_kwargs={'fileobj': self._fileobj})
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class DownloadSubmissionTask(SubmissionTask):
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"""Task for submitting tasks to execute a download"""
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def _get_download_output_manager_cls(self, transfer_future, osutil):
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"""Retrieves a class for managing output for a download
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:type transfer_future: s3transfer.futures.TransferFuture
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:param transfer_future: The transfer future for the request
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:type osutil: s3transfer.utils.OSUtils
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:param osutil: The os utility associated to the transfer
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:rtype: class of DownloadOutputManager
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:returns: The appropriate class to use for managing a specific type of
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input for downloads.
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"""
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download_manager_resolver_chain = [
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DownloadSpecialFilenameOutputManager,
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DownloadFilenameOutputManager,
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DownloadSeekableOutputManager,
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DownloadNonSeekableOutputManager,
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]
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fileobj = transfer_future.meta.call_args.fileobj
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for download_manager_cls in download_manager_resolver_chain:
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if download_manager_cls.is_compatible(fileobj, osutil):
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return download_manager_cls
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raise RuntimeError(
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'Output %s of type: %s is not supported.' % (
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fileobj, type(fileobj)))
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def _submit(self, client, config, osutil, request_executor, io_executor,
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transfer_future, bandwidth_limiter=None):
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"""
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:param client: The client associated with the transfer manager
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:type config: s3transfer.manager.TransferConfig
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:param config: The transfer config associated with the transfer
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manager
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:type osutil: s3transfer.utils.OSUtil
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:param osutil: The os utility associated to the transfer manager
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:type request_executor: s3transfer.futures.BoundedExecutor
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:param request_executor: The request executor associated with the
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transfer manager
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:type io_executor: s3transfer.futures.BoundedExecutor
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:param io_executor: The io executor associated with the
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transfer manager
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:type transfer_future: s3transfer.futures.TransferFuture
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:param transfer_future: The transfer future associated with the
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transfer request that tasks are being submitted for
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:type bandwidth_limiter: s3transfer.bandwidth.BandwidthLimiter
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:param bandwidth_limiter: The bandwidth limiter to use when
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downloading streams
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"""
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if transfer_future.meta.size is None:
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# If a size was not provided figure out the size for the
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# user.
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response = client.head_object(
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Bucket=transfer_future.meta.call_args.bucket,
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Key=transfer_future.meta.call_args.key,
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**transfer_future.meta.call_args.extra_args
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)
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transfer_future.meta.provide_transfer_size(
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response['ContentLength'])
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download_output_manager = self._get_download_output_manager_cls(
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transfer_future, osutil)(osutil, self._transfer_coordinator,
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io_executor)
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# If it is greater than threshold do a ranged download, otherwise
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# do a regular GetObject download.
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if transfer_future.meta.size < config.multipart_threshold:
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self._submit_download_request(
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client, config, osutil, request_executor, io_executor,
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download_output_manager, transfer_future, bandwidth_limiter)
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else:
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self._submit_ranged_download_request(
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client, config, osutil, request_executor, io_executor,
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download_output_manager, transfer_future, bandwidth_limiter)
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def _submit_download_request(self, client, config, osutil,
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request_executor, io_executor,
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download_output_manager, transfer_future,
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bandwidth_limiter):
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call_args = transfer_future.meta.call_args
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# Get a handle to the file that will be used for writing downloaded
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# contents
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fileobj = download_output_manager.get_fileobj_for_io_writes(
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transfer_future)
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# Get the needed callbacks for the task
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progress_callbacks = get_callbacks(transfer_future, 'progress')
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# Get any associated tags for the get object task.
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get_object_tag = download_output_manager.get_download_task_tag()
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# Get the final io task to run once the download is complete.
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final_task = download_output_manager.get_final_io_task()
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# Submit the task to download the object.
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self._transfer_coordinator.submit(
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request_executor,
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ImmediatelyWriteIOGetObjectTask(
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transfer_coordinator=self._transfer_coordinator,
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main_kwargs={
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'client': client,
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'bucket': call_args.bucket,
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'key': call_args.key,
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'fileobj': fileobj,
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'extra_args': call_args.extra_args,
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'callbacks': progress_callbacks,
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'max_attempts': config.num_download_attempts,
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'download_output_manager': download_output_manager,
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'io_chunksize': config.io_chunksize,
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'bandwidth_limiter': bandwidth_limiter
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},
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done_callbacks=[final_task]
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),
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tag=get_object_tag
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)
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def _submit_ranged_download_request(self, client, config, osutil,
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request_executor, io_executor,
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download_output_manager,
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transfer_future,
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bandwidth_limiter):
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call_args = transfer_future.meta.call_args
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# Get the needed progress callbacks for the task
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progress_callbacks = get_callbacks(transfer_future, 'progress')
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# Get a handle to the file that will be used for writing downloaded
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# contents
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fileobj = download_output_manager.get_fileobj_for_io_writes(
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transfer_future)
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# Determine the number of parts
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part_size = config.multipart_chunksize
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num_parts = int(
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math.ceil(transfer_future.meta.size / float(part_size)))
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# Get any associated tags for the get object task.
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get_object_tag = download_output_manager.get_download_task_tag()
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# Callback invoker to submit the final io task once all downloads
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# are complete.
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finalize_download_invoker = CountCallbackInvoker(
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self._get_final_io_task_submission_callback(
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download_output_manager, io_executor
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)
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)
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for i in range(num_parts):
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# Calculate the range parameter
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range_parameter = calculate_range_parameter(
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part_size, i, num_parts)
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# Inject the Range parameter to the parameters to be passed in
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# as extra args
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extra_args = {'Range': range_parameter}
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extra_args.update(call_args.extra_args)
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finalize_download_invoker.increment()
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# Submit the ranged downloads
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self._transfer_coordinator.submit(
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request_executor,
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GetObjectTask(
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transfer_coordinator=self._transfer_coordinator,
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main_kwargs={
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'client': client,
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'bucket': call_args.bucket,
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'key': call_args.key,
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'fileobj': fileobj,
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'extra_args': extra_args,
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'callbacks': progress_callbacks,
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'max_attempts': config.num_download_attempts,
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'start_index': i * part_size,
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'download_output_manager': download_output_manager,
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'io_chunksize': config.io_chunksize,
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'bandwidth_limiter': bandwidth_limiter
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},
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done_callbacks=[finalize_download_invoker.decrement]
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),
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tag=get_object_tag
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)
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finalize_download_invoker.finalize()
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def _get_final_io_task_submission_callback(self, download_manager,
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io_executor):
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final_task = download_manager.get_final_io_task()
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return FunctionContainer(
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self._transfer_coordinator.submit, io_executor, final_task)
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def _calculate_range_param(self, part_size, part_index, num_parts):
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# Used to calculate the Range parameter
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start_range = part_index * part_size
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if part_index == num_parts - 1:
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end_range = ''
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else:
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end_range = start_range + part_size - 1
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range_param = 'bytes=%s-%s' % (start_range, end_range)
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return range_param
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class GetObjectTask(Task):
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def _main(self, client, bucket, key, fileobj, extra_args, callbacks,
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max_attempts, download_output_manager, io_chunksize,
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start_index=0, bandwidth_limiter=None):
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"""Downloads an object and places content into io queue
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:param client: The client to use when calling GetObject
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:param bucket: The bucket to download from
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:param key: The key to download from
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:param fileobj: The file handle to write content to
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:param exta_args: Any extra arguements to include in GetObject request
|
|
:param callbacks: List of progress callbacks to invoke on download
|
|
:param max_attempts: The number of retries to do when downloading
|
|
:param download_output_manager: The download output manager associated
|
|
with the current download.
|
|
:param io_chunksize: The size of each io chunk to read from the
|
|
download stream and queue in the io queue.
|
|
:param start_index: The location in the file to start writing the
|
|
content of the key to.
|
|
:param bandwidth_limiter: The bandwidth limiter to use when throttling
|
|
the downloading of data in streams.
|
|
"""
|
|
last_exception = None
|
|
for i in range(max_attempts):
|
|
try:
|
|
response = client.get_object(
|
|
Bucket=bucket, Key=key, **extra_args)
|
|
streaming_body = StreamReaderProgress(
|
|
response['Body'], callbacks)
|
|
if bandwidth_limiter:
|
|
streaming_body = \
|
|
bandwidth_limiter.get_bandwith_limited_stream(
|
|
streaming_body, self._transfer_coordinator)
|
|
|
|
current_index = start_index
|
|
chunks = DownloadChunkIterator(streaming_body, io_chunksize)
|
|
for chunk in chunks:
|
|
# If the transfer is done because of a cancellation
|
|
# or error somewhere else, stop trying to submit more
|
|
# data to be written and break out of the download.
|
|
if not self._transfer_coordinator.done():
|
|
self._handle_io(
|
|
download_output_manager, fileobj, chunk,
|
|
current_index
|
|
)
|
|
current_index += len(chunk)
|
|
else:
|
|
return
|
|
return
|
|
except S3_RETRYABLE_ERRORS as e:
|
|
logger.debug("Retrying exception caught (%s), "
|
|
"retrying request, (attempt %s / %s)", e, i,
|
|
max_attempts, exc_info=True)
|
|
last_exception = e
|
|
# Also invoke the progress callbacks to indicate that we
|
|
# are trying to download the stream again and all progress
|
|
# for this GetObject has been lost.
|
|
invoke_progress_callbacks(
|
|
callbacks, start_index - current_index)
|
|
continue
|
|
raise RetriesExceededError(last_exception)
|
|
|
|
def _handle_io(self, download_output_manager, fileobj, chunk, index):
|
|
download_output_manager.queue_file_io_task(fileobj, chunk, index)
|
|
|
|
|
|
class ImmediatelyWriteIOGetObjectTask(GetObjectTask):
|
|
"""GetObjectTask that immediately writes to the provided file object
|
|
|
|
This is useful for downloads where it is known only one thread is
|
|
downloading the object so there is no reason to go through the
|
|
overhead of using an IO queue and executor.
|
|
"""
|
|
def _handle_io(self, download_output_manager, fileobj, chunk, index):
|
|
task = download_output_manager.get_io_write_task(fileobj, chunk, index)
|
|
task()
|
|
|
|
|
|
class IOWriteTask(Task):
|
|
def _main(self, fileobj, data, offset):
|
|
"""Pulls off an io queue to write contents to a file
|
|
|
|
:param f: The file handle to write content to
|
|
:param data: The data to write
|
|
:param offset: The offset to write the data to.
|
|
"""
|
|
fileobj.seek(offset)
|
|
fileobj.write(data)
|
|
|
|
|
|
class IOStreamingWriteTask(Task):
|
|
"""Task for writing data to a non-seekable stream."""
|
|
|
|
def _main(self, fileobj, data):
|
|
"""Write data to a fileobj.
|
|
|
|
Data will be written directly to the fileboj without
|
|
any prior seeking.
|
|
|
|
:param fileobj: The fileobj to write content to
|
|
:param data: The data to write
|
|
|
|
"""
|
|
fileobj.write(data)
|
|
|
|
|
|
class IORenameFileTask(Task):
|
|
"""A task to rename a temporary file to its final filename
|
|
|
|
:param f: The file handle that content was written to.
|
|
:param final_filename: The final name of the file to rename to
|
|
upon completion of writing the contents.
|
|
:param osutil: OS utility
|
|
"""
|
|
def _main(self, fileobj, final_filename, osutil):
|
|
fileobj.close()
|
|
osutil.rename_file(fileobj.name, final_filename)
|
|
|
|
|
|
class IOCloseTask(Task):
|
|
"""A task to close out a file once the download is complete.
|
|
|
|
:param fileobj: The fileobj to close.
|
|
"""
|
|
def _main(self, fileobj):
|
|
fileobj.close()
|
|
|
|
|
|
class CompleteDownloadNOOPTask(Task):
|
|
"""A NOOP task to serve as an indicator that the download is complete
|
|
|
|
Note that the default for is_final is set to True because this should
|
|
always be the last task.
|
|
"""
|
|
def __init__(self, transfer_coordinator, main_kwargs=None,
|
|
pending_main_kwargs=None, done_callbacks=None,
|
|
is_final=True):
|
|
super(CompleteDownloadNOOPTask, self).__init__(
|
|
transfer_coordinator=transfer_coordinator,
|
|
main_kwargs=main_kwargs,
|
|
pending_main_kwargs=pending_main_kwargs,
|
|
done_callbacks=done_callbacks,
|
|
is_final=is_final
|
|
)
|
|
|
|
def _main(self):
|
|
pass
|
|
|
|
|
|
class DownloadChunkIterator(object):
|
|
def __init__(self, body, chunksize):
|
|
"""Iterator to chunk out a downloaded S3 stream
|
|
|
|
:param body: A readable file-like object
|
|
:param chunksize: The amount to read each time
|
|
"""
|
|
self._body = body
|
|
self._chunksize = chunksize
|
|
self._num_reads = 0
|
|
|
|
def __iter__(self):
|
|
return self
|
|
|
|
def __next__(self):
|
|
chunk = self._body.read(self._chunksize)
|
|
self._num_reads += 1
|
|
if chunk:
|
|
return chunk
|
|
elif self._num_reads == 1:
|
|
# Even though the response may have not had any
|
|
# content, we still want to account for an empty object's
|
|
# existance so return the empty chunk for that initial
|
|
# read.
|
|
return chunk
|
|
raise StopIteration()
|
|
|
|
next = __next__
|
|
|
|
|
|
class DeferQueue(object):
|
|
"""IO queue that defers write requests until they are queued sequentially.
|
|
|
|
This class is used to track IO data for a *single* fileobj.
|
|
|
|
You can send data to this queue, and it will defer any IO write requests
|
|
until it has the next contiguous block available (starting at 0).
|
|
|
|
"""
|
|
def __init__(self):
|
|
self._writes = []
|
|
self._pending_offsets = set()
|
|
self._next_offset = 0
|
|
|
|
def request_writes(self, offset, data):
|
|
"""Request any available writes given new incoming data.
|
|
|
|
You call this method by providing new data along with the
|
|
offset associated with the data. If that new data unlocks
|
|
any contiguous writes that can now be submitted, this
|
|
method will return all applicable writes.
|
|
|
|
This is done with 1 method call so you don't have to
|
|
make two method calls (put(), get()) which acquires a lock
|
|
each method call.
|
|
|
|
"""
|
|
if offset < self._next_offset:
|
|
# This is a request for a write that we've already
|
|
# seen. This can happen in the event of a retry
|
|
# where if we retry at at offset N/2, we'll requeue
|
|
# offsets 0-N/2 again.
|
|
return []
|
|
writes = []
|
|
if offset in self._pending_offsets:
|
|
# We've already queued this offset so this request is
|
|
# a duplicate. In this case we should ignore
|
|
# this request and prefer what's already queued.
|
|
return []
|
|
heapq.heappush(self._writes, (offset, data))
|
|
self._pending_offsets.add(offset)
|
|
while self._writes and self._writes[0][0] == self._next_offset:
|
|
next_write = heapq.heappop(self._writes)
|
|
writes.append({'offset': next_write[0], 'data': next_write[1]})
|
|
self._pending_offsets.remove(next_write[0])
|
|
self._next_offset += len(next_write[1])
|
|
return writes
|