# Copyright 2016 Amazon.com, Inc. or its affiliates. All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"). You # may not use this file except in compliance with the License. A copy of # the License is located at # # http://aws.amazon.com/apache2.0/ # # or in the "license" file accompanying this file. This file is # distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF # ANY KIND, either express or implied. See the License for the specific # language governing permissions and limitations under the License. import copy import logging import threading from botocore.compat import six from s3transfer.constants import KB, MB from s3transfer.constants import ALLOWED_DOWNLOAD_ARGS from s3transfer.utils import get_callbacks from s3transfer.utils import signal_transferring from s3transfer.utils import signal_not_transferring from s3transfer.utils import CallArgs from s3transfer.utils import OSUtils from s3transfer.utils import TaskSemaphore from s3transfer.utils import SlidingWindowSemaphore from s3transfer.exceptions import CancelledError from s3transfer.exceptions import FatalError from s3transfer.futures import IN_MEMORY_DOWNLOAD_TAG from s3transfer.futures import IN_MEMORY_UPLOAD_TAG from s3transfer.futures import BoundedExecutor from s3transfer.futures import TransferFuture from s3transfer.futures import TransferMeta from s3transfer.futures import TransferCoordinator from s3transfer.download import DownloadSubmissionTask from s3transfer.upload import UploadSubmissionTask from s3transfer.copies import CopySubmissionTask from s3transfer.delete import DeleteSubmissionTask from s3transfer.bandwidth import LeakyBucket from s3transfer.bandwidth import BandwidthLimiter logger = logging.getLogger(__name__) class TransferConfig(object): def __init__(self, multipart_threshold=8 * MB, multipart_chunksize=8 * MB, max_request_concurrency=10, max_submission_concurrency=5, max_request_queue_size=1000, max_submission_queue_size=1000, max_io_queue_size=1000, io_chunksize=256 * KB, num_download_attempts=5, max_in_memory_upload_chunks=10, max_in_memory_download_chunks=10, max_bandwidth=None): """Configurations for the transfer mangager :param multipart_threshold: The threshold for which multipart transfers occur. :param max_request_concurrency: The maximum number of S3 API transfer-related requests that can happen at a time. :param max_submission_concurrency: The maximum number of threads processing a call to a TransferManager method. Processing a call usually entails determining which S3 API requests that need to be enqueued, but does **not** entail making any of the S3 API data transfering requests needed to perform the transfer. The threads controlled by ``max_request_concurrency`` is responsible for that. :param multipart_chunksize: The size of each transfer if a request becomes a multipart transfer. :param max_request_queue_size: The maximum amount of S3 API requests that can be queued at a time. A value of zero means that there is no maximum. :param max_submission_queue_size: The maximum amount of TransferManager method calls that can be queued at a time. A value of zero means that there is no maximum. :param max_io_queue_size: The maximum amount of read parts that can be queued to be written to disk per download. A value of zero means that there is no maximum. The default size for each element in this queue is 8 KB. :param io_chunksize: The max size of each chunk in the io queue. Currently, this is size used when reading from the downloaded stream as well. :param num_download_attempts: The number of download attempts that will be tried upon errors with downloading an object in S3. Note that these retries account for errors that occur when streamming down the data from s3 (i.e. socket errors and read timeouts that occur after recieving an OK response from s3). Other retryable exceptions such as throttling errors and 5xx errors are already retried by botocore (this default is 5). The ``num_download_attempts`` does not take into account the number of exceptions retried by botocore. :param max_in_memory_upload_chunks: The number of chunks that can be stored in memory at a time for all ongoing upload requests. This pertains to chunks of data that need to be stored in memory during an upload if the data is sourced from a file-like object. The total maximum memory footprint due to a in-memory upload chunks is roughly equal to: max_in_memory_upload_chunks * multipart_chunksize + max_submission_concurrency * multipart_chunksize ``max_submission_concurrency`` has an affect on this value because for each thread pulling data off of a file-like object, they may be waiting with a single read chunk to be submitted for upload because the ``max_in_memory_upload_chunks`` value has been reached by the threads making the upload request. :param max_in_memory_download_chunks: The number of chunks that can be buffered in memory and **not** in the io queue at a time for all ongoing dowload requests. This pertains specifically to file-like objects that cannot be seeked. The total maximum memory footprint due to a in-memory download chunks is roughly equal to: max_in_memory_download_chunks * multipart_chunksize :param max_bandwidth: The maximum bandwidth that will be consumed in uploading and downloading file content. The value is in terms of bytes per second. """ self.multipart_threshold = multipart_threshold self.multipart_chunksize = multipart_chunksize self.max_request_concurrency = max_request_concurrency self.max_submission_concurrency = max_submission_concurrency self.max_request_queue_size = max_request_queue_size self.max_submission_queue_size = max_submission_queue_size self.max_io_queue_size = max_io_queue_size self.io_chunksize = io_chunksize self.num_download_attempts = num_download_attempts self.max_in_memory_upload_chunks = max_in_memory_upload_chunks self.max_in_memory_download_chunks = max_in_memory_download_chunks self.max_bandwidth = max_bandwidth self._validate_attrs_are_nonzero() def _validate_attrs_are_nonzero(self): for attr, attr_val, in self.__dict__.items(): if attr_val is not None and attr_val <= 0: raise ValueError( 'Provided parameter %s of value %s must be greater than ' '0.' % (attr, attr_val)) class TransferManager(object): ALLOWED_DOWNLOAD_ARGS = ALLOWED_DOWNLOAD_ARGS ALLOWED_UPLOAD_ARGS = [ 'ACL', 'CacheControl', 'ContentDisposition', 'ContentEncoding', 'ContentLanguage', 'ContentType', 'Expires', 'GrantFullControl', 'GrantRead', 'GrantReadACP', 'GrantWriteACP', 'Metadata', 'RequestPayer', 'ServerSideEncryption', 'StorageClass', 'SSECustomerAlgorithm', 'SSECustomerKey', 'SSECustomerKeyMD5', 'SSEKMSKeyId', 'SSEKMSEncryptionContext', 'Tagging', 'WebsiteRedirectLocation' ] ALLOWED_COPY_ARGS = ALLOWED_UPLOAD_ARGS + [ 'CopySourceIfMatch', 'CopySourceIfModifiedSince', 'CopySourceIfNoneMatch', 'CopySourceIfUnmodifiedSince', 'CopySourceSSECustomerAlgorithm', 'CopySourceSSECustomerKey', 'CopySourceSSECustomerKeyMD5', 'MetadataDirective', 'TaggingDirective', ] ALLOWED_DELETE_ARGS = [ 'MFA', 'VersionId', 'RequestPayer', ] def __init__(self, client, config=None, osutil=None, executor_cls=None): """A transfer manager interface for Amazon S3 :param client: Client to be used by the manager :param config: TransferConfig to associate specific configurations :param osutil: OSUtils object to use for os-related behavior when using with transfer manager. :type executor_cls: s3transfer.futures.BaseExecutor :param executor_cls: The class of executor to use with the transfer manager. By default, concurrent.futures.ThreadPoolExecutor is used. """ self._client = client self._config = config if config is None: self._config = TransferConfig() self._osutil = osutil if osutil is None: self._osutil = OSUtils() self._coordinator_controller = TransferCoordinatorController() # A counter to create unique id's for each transfer submitted. self._id_counter = 0 # The executor responsible for making S3 API transfer requests self._request_executor = BoundedExecutor( max_size=self._config.max_request_queue_size, max_num_threads=self._config.max_request_concurrency, tag_semaphores={ IN_MEMORY_UPLOAD_TAG: TaskSemaphore( self._config.max_in_memory_upload_chunks), IN_MEMORY_DOWNLOAD_TAG: SlidingWindowSemaphore( self._config.max_in_memory_download_chunks) }, executor_cls=executor_cls ) # The executor responsible for submitting the necessary tasks to # perform the desired transfer self._submission_executor = BoundedExecutor( max_size=self._config.max_submission_queue_size, max_num_threads=self._config.max_submission_concurrency, executor_cls=executor_cls ) # There is one thread available for writing to disk. It will handle # downloads for all files. self._io_executor = BoundedExecutor( max_size=self._config.max_io_queue_size, max_num_threads=1, executor_cls=executor_cls ) # The component responsible for limiting bandwidth usage if it # is configured. self._bandwidth_limiter = None if self._config.max_bandwidth is not None: logger.debug( 'Setting max_bandwidth to %s', self._config.max_bandwidth) leaky_bucket = LeakyBucket(self._config.max_bandwidth) self._bandwidth_limiter = BandwidthLimiter(leaky_bucket) self._register_handlers() @property def client(self): return self._client @property def config(self): return self._config def upload(self, fileobj, bucket, key, extra_args=None, subscribers=None): """Uploads a file to S3 :type fileobj: str or seekable file-like object :param fileobj: The name of a file to upload or a seekable file-like object to upload. It is recommended to use a filename because file-like objects may result in higher memory usage. :type bucket: str :param bucket: The name of the bucket to upload to :type key: str :param key: The name of the key to upload to :type extra_args: dict :param extra_args: Extra arguments that may be passed to the client operation :type subscribers: list(s3transfer.subscribers.BaseSubscriber) :param subscribers: The list of subscribers to be invoked in the order provided based on the event emit during the process of the transfer request. :rtype: s3transfer.futures.TransferFuture :returns: Transfer future representing the upload """ if extra_args is None: extra_args = {} if subscribers is None: subscribers = [] self._validate_all_known_args(extra_args, self.ALLOWED_UPLOAD_ARGS) call_args = CallArgs( fileobj=fileobj, bucket=bucket, key=key, extra_args=extra_args, subscribers=subscribers ) extra_main_kwargs = {} if self._bandwidth_limiter: extra_main_kwargs['bandwidth_limiter'] = self._bandwidth_limiter return self._submit_transfer( call_args, UploadSubmissionTask, extra_main_kwargs) def download(self, bucket, key, fileobj, extra_args=None, subscribers=None): """Downloads a file from S3 :type bucket: str :param bucket: The name of the bucket to download from :type key: str :param key: The name of the key to download from :type fileobj: str or seekable file-like object :param fileobj: The name of a file to download or a seekable file-like object to download. It is recommended to use a filename because file-like objects may result in higher memory usage. :type extra_args: dict :param extra_args: Extra arguments that may be passed to the client operation :type subscribers: list(s3transfer.subscribers.BaseSubscriber) :param subscribers: The list of subscribers to be invoked in the order provided based on the event emit during the process of the transfer request. :rtype: s3transfer.futures.TransferFuture :returns: Transfer future representing the download """ if extra_args is None: extra_args = {} if subscribers is None: subscribers = [] self._validate_all_known_args(extra_args, self.ALLOWED_DOWNLOAD_ARGS) call_args = CallArgs( bucket=bucket, key=key, fileobj=fileobj, extra_args=extra_args, subscribers=subscribers ) extra_main_kwargs = {'io_executor': self._io_executor} if self._bandwidth_limiter: extra_main_kwargs['bandwidth_limiter'] = self._bandwidth_limiter return self._submit_transfer( call_args, DownloadSubmissionTask, extra_main_kwargs) def copy(self, copy_source, bucket, key, extra_args=None, subscribers=None, source_client=None): """Copies a file in S3 :type copy_source: dict :param copy_source: The name of the source bucket, key name of the source object, and optional version ID of the source object. The dictionary format is: ``{'Bucket': 'bucket', 'Key': 'key', 'VersionId': 'id'}``. Note that the ``VersionId`` key is optional and may be omitted. :type bucket: str :param bucket: The name of the bucket to copy to :type key: str :param key: The name of the key to copy to :type extra_args: dict :param extra_args: Extra arguments that may be passed to the client operation :type subscribers: a list of subscribers :param subscribers: The list of subscribers to be invoked in the order provided based on the event emit during the process of the transfer request. :type source_client: botocore or boto3 Client :param source_client: The client to be used for operation that may happen at the source object. For example, this client is used for the head_object that determines the size of the copy. If no client is provided, the transfer manager's client is used as the client for the source object. :rtype: s3transfer.futures.TransferFuture :returns: Transfer future representing the copy """ if extra_args is None: extra_args = {} if subscribers is None: subscribers = [] if source_client is None: source_client = self._client self._validate_all_known_args(extra_args, self.ALLOWED_COPY_ARGS) call_args = CallArgs( copy_source=copy_source, bucket=bucket, key=key, extra_args=extra_args, subscribers=subscribers, source_client=source_client ) return self._submit_transfer(call_args, CopySubmissionTask) def delete(self, bucket, key, extra_args=None, subscribers=None): """Delete an S3 object. :type bucket: str :param bucket: The name of the bucket. :type key: str :param key: The name of the S3 object to delete. :type extra_args: dict :param extra_args: Extra arguments that may be passed to the DeleteObject call. :type subscribers: list :param subscribers: A list of subscribers to be invoked during the process of the transfer request. Note that the ``on_progress`` callback is not invoked during object deletion. :rtype: s3transfer.futures.TransferFuture :return: Transfer future representing the deletion. """ if extra_args is None: extra_args = {} if subscribers is None: subscribers = [] self._validate_all_known_args(extra_args, self.ALLOWED_DELETE_ARGS) call_args = CallArgs( bucket=bucket, key=key, extra_args=extra_args, subscribers=subscribers ) return self._submit_transfer(call_args, DeleteSubmissionTask) def _validate_all_known_args(self, actual, allowed): for kwarg in actual: if kwarg not in allowed: raise ValueError( "Invalid extra_args key '%s', " "must be one of: %s" % ( kwarg, ', '.join(allowed))) def _submit_transfer(self, call_args, submission_task_cls, extra_main_kwargs=None): if not extra_main_kwargs: extra_main_kwargs = {} # Create a TransferFuture to return back to the user transfer_future, components = self._get_future_with_components( call_args) # Add any provided done callbacks to the created transfer future # to be invoked on the transfer future being complete. for callback in get_callbacks(transfer_future, 'done'): components['coordinator'].add_done_callback(callback) # Get the main kwargs needed to instantiate the submission task main_kwargs = self._get_submission_task_main_kwargs( transfer_future, extra_main_kwargs) # Submit a SubmissionTask that will submit all of the necessary # tasks needed to complete the S3 transfer. self._submission_executor.submit( submission_task_cls( transfer_coordinator=components['coordinator'], main_kwargs=main_kwargs ) ) # Increment the unique id counter for future transfer requests self._id_counter += 1 return transfer_future def _get_future_with_components(self, call_args): transfer_id = self._id_counter # Creates a new transfer future along with its components transfer_coordinator = TransferCoordinator(transfer_id=transfer_id) # Track the transfer coordinator for transfers to manage. self._coordinator_controller.add_transfer_coordinator( transfer_coordinator) # Also make sure that the transfer coordinator is removed once # the transfer completes so it does not stick around in memory. transfer_coordinator.add_done_callback( self._coordinator_controller.remove_transfer_coordinator, transfer_coordinator) components = { 'meta': TransferMeta(call_args, transfer_id=transfer_id), 'coordinator': transfer_coordinator } transfer_future = TransferFuture(**components) return transfer_future, components def _get_submission_task_main_kwargs( self, transfer_future, extra_main_kwargs): main_kwargs = { 'client': self._client, 'config': self._config, 'osutil': self._osutil, 'request_executor': self._request_executor, 'transfer_future': transfer_future } main_kwargs.update(extra_main_kwargs) return main_kwargs def _register_handlers(self): # Register handlers to enable/disable callbacks on uploads. event_name = 'request-created.s3' self._client.meta.events.register_first( event_name, signal_not_transferring, unique_id='s3upload-not-transferring') self._client.meta.events.register_last( event_name, signal_transferring, unique_id='s3upload-transferring') def __enter__(self): return self def __exit__(self, exc_type, exc_value, *args): cancel = False cancel_msg = '' cancel_exc_type = FatalError # If a exception was raised in the context handler, signal to cancel # all of the inprogress futures in the shutdown. if exc_type: cancel = True cancel_msg = six.text_type(exc_value) if not cancel_msg: cancel_msg = repr(exc_value) # If it was a KeyboardInterrupt, the cancellation was initiated # by the user. if isinstance(exc_value, KeyboardInterrupt): cancel_exc_type = CancelledError self._shutdown(cancel, cancel_msg, cancel_exc_type) def shutdown(self, cancel=False, cancel_msg=''): """Shutdown the TransferManager It will wait till all transfers complete before it completely shuts down. :type cancel: boolean :param cancel: If True, calls TransferFuture.cancel() for all in-progress in transfers. This is useful if you want the shutdown to happen quicker. :type cancel_msg: str :param cancel_msg: The message to specify if canceling all in-progress transfers. """ self._shutdown(cancel, cancel, cancel_msg) def _shutdown(self, cancel, cancel_msg, exc_type=CancelledError): if cancel: # Cancel all in-flight transfers if requested, before waiting # for them to complete. self._coordinator_controller.cancel(cancel_msg, exc_type) try: # Wait until there are no more in-progress transfers. This is # wrapped in a try statement because this can be interrupted # with a KeyboardInterrupt that needs to be caught. self._coordinator_controller.wait() except KeyboardInterrupt: # If not errors were raised in the try block, the cancel should # have no coordinators it needs to run cancel on. If there was # an error raised in the try statement we want to cancel all of # the inflight transfers before shutting down to speed that # process up. self._coordinator_controller.cancel('KeyboardInterrupt()') raise finally: # Shutdown all of the executors. self._submission_executor.shutdown() self._request_executor.shutdown() self._io_executor.shutdown() class TransferCoordinatorController(object): def __init__(self): """Abstraction to control all transfer coordinators This abstraction allows the manager to wait for inprogress transfers to complete and cancel all inprogress transfers. """ self._lock = threading.Lock() self._tracked_transfer_coordinators = set() @property def tracked_transfer_coordinators(self): """The set of transfer coordinators being tracked""" with self._lock: # We return a copy because the set is mutable and if you were to # iterate over the set, it may be changing in length due to # additions and removals of transfer coordinators. return copy.copy(self._tracked_transfer_coordinators) def add_transfer_coordinator(self, transfer_coordinator): """Adds a transfer coordinator of a transfer to be canceled if needed :type transfer_coordinator: s3transfer.futures.TransferCoordinator :param transfer_coordinator: The transfer coordinator for the particular transfer """ with self._lock: self._tracked_transfer_coordinators.add(transfer_coordinator) def remove_transfer_coordinator(self, transfer_coordinator): """Remove a transfer coordinator from cancelation consideration Typically, this method is invoked by the transfer coordinator itself to remove its self when it completes its transfer. :type transfer_coordinator: s3transfer.futures.TransferCoordinator :param transfer_coordinator: The transfer coordinator for the particular transfer """ with self._lock: self._tracked_transfer_coordinators.remove(transfer_coordinator) def cancel(self, msg='', exc_type=CancelledError): """Cancels all inprogress transfers This cancels the inprogress transfers by calling cancel() on all tracked transfer coordinators. :param msg: The message to pass on to each transfer coordinator that gets cancelled. :param exc_type: The type of exception to set for the cancellation """ for transfer_coordinator in self.tracked_transfer_coordinators: transfer_coordinator.cancel(msg, exc_type) def wait(self): """Wait until there are no more inprogress transfers This will not stop when failures are encountered and not propogate any of these errors from failed transfers, but it can be interrupted with a KeyboardInterrupt. """ try: transfer_coordinator = None for transfer_coordinator in self.tracked_transfer_coordinators: transfer_coordinator.result() except KeyboardInterrupt: logger.debug('Received KeyboardInterrupt in wait()') # If Keyboard interrupt is raised while waiting for # the result, then exit out of the wait and raise the # exception if transfer_coordinator: logger.debug( 'On KeyboardInterrupt was waiting for %s', transfer_coordinator) raise except Exception: # A general exception could have been thrown because # of result(). We just want to ignore this and continue # because we at least know that the transfer coordinator # has completed. pass