# -*- coding: utf-8 -*- # # Copyright (C) 2019 Radim Rehurek # # This code is distributed under the terms and conditions # from the MIT License (MIT). # """Implements file-like objects for reading and writing from/to AWS S3.""" from __future__ import annotations import http import io import functools import logging import time import warnings from typing import ( Callable, List, TYPE_CHECKING, ) try: import boto3 import botocore.client import botocore.exceptions import urllib3.exceptions except ImportError: MISSING_DEPS = True import smart_open.bytebuffer import smart_open.concurrency import smart_open.utils from smart_open import constants if TYPE_CHECKING: from mypy_boto3_s3.client import S3Client from typing_extensions import Buffer logger = logging.getLogger(__name__) # # AWS puts restrictions on the part size for multipart uploads. # Each part must be more than 5MB, and less than 5GB. # # On top of that, our MultipartWriter has a min_part_size option. # In retrospect, it's an unfortunate name, because it conflicts with the # minimum allowable part size (5MB), but it's too late to change it, because # people are using that parameter (unlike the MIN, DEFAULT, MAX constants). # It really just means "part size": as soon as you have this many bytes, # write a part to S3 (see the MultipartWriter.write method). # MIN_PART_SIZE = 5 * 1024 ** 2 """The absolute minimum permitted by Amazon.""" DEFAULT_PART_SIZE = 50 * 1024**2 """The default part size for S3 multipart uploads, chosen carefully by smart_open""" MAX_PART_SIZE = 5 * 1024 ** 3 """The absolute maximum permitted by Amazon.""" SCHEMES = ("s3", "s3n", 's3u', "s3a") DEFAULT_PORT = 443 DEFAULT_HOST = 's3.amazonaws.com' DEFAULT_BUFFER_SIZE = 128 * 1024 URI_EXAMPLES = ( 's3://my_bucket/my_key', 's3://my_key:my_secret@my_bucket/my_key', 's3://my_key:my_secret@my_server:my_port@my_bucket/my_key', ) # Returned by AWS when we try to seek beyond EOF. _OUT_OF_RANGE = 'InvalidRange' class Retry: def __init__(self): self.attempts: int = 6 self.sleep_seconds: int = 10 self.exceptions: List[Exception] = [botocore.exceptions.EndpointConnectionError] self.client_error_codes: List[str] = ['NoSuchUpload'] def _do(self, fn: Callable): for attempt in range(self.attempts): try: return fn() except tuple(self.exceptions) as err: logger.critical( 'Caught non-fatal %s, retrying %d more times', err, self.attempts - attempt - 1, ) logger.exception(err) time.sleep(self.sleep_seconds) except botocore.exceptions.ClientError as err: error_code = err.response['Error'].get('Code') if error_code not in self.client_error_codes: raise logger.critical( 'Caught non-fatal ClientError (%s), retrying %d more times', error_code, self.attempts - attempt - 1, ) logger.exception(err) time.sleep(self.sleep_seconds) else: logger.critical('encountered too many non-fatal errors, giving up') raise IOError('%s failed after %d attempts', fn.func, self.attempts) # # The retry mechanism for this submodule. Client code may modify it, e.g. by # updating RETRY.sleep_seconds and friends. # if 'MISSING_DEPS' not in locals(): RETRY = Retry() class _ClientWrapper: """Wraps a client to inject the appropriate keyword args into each method call. The keyword args are a dictionary keyed by the fully qualified method name. For example, S3.Client.create_multipart_upload. See https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/s3.html#client This wrapper behaves identically to the client otherwise. """ def __init__(self, client, kwargs): self.client = client self.kwargs = kwargs def __getattr__(self, method_name): method = getattr(self.client, method_name) kwargs = self.kwargs.get('S3.Client.%s' % method_name, {}) return functools.partial(method, **kwargs) def parse_uri(uri_as_string): # # Restrictions on bucket names and labels: # # - Bucket names must be at least 3 and no more than 63 characters long. # - Bucket names must be a series of one or more labels. # - Adjacent labels are separated by a single period (.). # - Bucket names can contain lowercase letters, numbers, and hyphens. # - Each label must start and end with a lowercase letter or a number. # # We use the above as a guide only, and do not perform any validation. We # let boto3 take care of that for us. # split_uri = smart_open.utils.safe_urlsplit(uri_as_string) assert split_uri.scheme in SCHEMES port = DEFAULT_PORT host = DEFAULT_HOST ordinary_calling_format = False # # These defaults tell boto3 to look for credentials elsewhere # access_id, access_secret = None, None # # Common URI template [secret:key@][host[:port]@]bucket/object # # The urlparse function doesn't handle the above schema, so we have to do # it ourselves. # uri = split_uri.netloc + split_uri.path # # Attempt to extract edge-case authentication details from the URL. # # See: # 1. https://summitroute.com/blog/2018/06/20/aws_security_credential_formats/ # 2. test_s3_uri_with_credentials* in test_smart_open.py for example edge cases # if '@' in uri: maybe_auth, rest = uri.split('@', 1) if ':' in maybe_auth: maybe_id, maybe_secret = maybe_auth.split(':', 1) if '/' not in maybe_id: access_id, access_secret = maybe_id, maybe_secret uri = rest head, key_id = uri.split('/', 1) if '@' in head and ':' in head: ordinary_calling_format = True host_port, bucket_id = head.split('@') host, port = host_port.split(':', 1) port = int(port) elif '@' in head: ordinary_calling_format = True host, bucket_id = head.split('@') else: bucket_id = head return dict( scheme=split_uri.scheme, bucket_id=bucket_id, key_id=key_id, port=port, host=host, ordinary_calling_format=ordinary_calling_format, access_id=access_id, access_secret=access_secret, ) def _consolidate_params(uri, transport_params): """Consolidates the parsed Uri with the additional parameters. This is necessary because the user can pass some of the parameters can in two different ways: 1) Via the URI itself 2) Via the transport parameters These are not mutually exclusive, but we have to pick one over the other in a sensible way in order to proceed. """ transport_params = dict(transport_params) def inject(**kwargs): try: client_kwargs = transport_params['client_kwargs'] except KeyError: client_kwargs = transport_params['client_kwargs'] = {} try: init_kwargs = client_kwargs['S3.Client'] except KeyError: init_kwargs = client_kwargs['S3.Client'] = {} init_kwargs.update(**kwargs) client = transport_params.get('client') if client is not None and (uri['access_id'] or uri['access_secret']): logger.warning( 'ignoring credentials parsed from URL because they conflict with ' 'transport_params["client"]. Set transport_params["client"] to None ' 'to suppress this warning.' ) uri.update(access_id=None, access_secret=None) elif (uri['access_id'] and uri['access_secret']): inject( aws_access_key_id=uri['access_id'], aws_secret_access_key=uri['access_secret'], ) uri.update(access_id=None, access_secret=None) if client is not None and uri['host'] != DEFAULT_HOST: logger.warning( 'ignoring endpoint_url parsed from URL because they conflict with ' 'transport_params["client"]. Set transport_params["client"] to None ' 'to suppress this warning.' ) uri.update(host=None) elif uri['host'] != DEFAULT_HOST: if uri['scheme'] == 's3u': scheme = 'http' else: scheme = 'https' inject(endpoint_url=scheme + '://%(host)s:%(port)d' % uri) uri.update(host=None) return uri, transport_params def open_uri(uri, mode, transport_params): deprecated = ( 'multipart_upload_kwargs', 'object_kwargs', 'resource', 'resource_kwargs', 'session', 'singlepart_upload_kwargs', ) detected = [k for k in deprecated if k in transport_params] if detected: doc_url = ( 'https://github.com/RaRe-Technologies/smart_open/blob/develop/' 'MIGRATING_FROM_OLDER_VERSIONS.rst' ) # # We use warnings.warn /w UserWarning instead of logger.warn here because # # 1) Not everyone has logging enabled; and # 2) check_kwargs (below) already uses logger.warn with a similar message # # https://github.com/RaRe-Technologies/smart_open/issues/614 # message = ( 'ignoring the following deprecated transport parameters: %r. ' 'See <%s> for details' % (detected, doc_url) ) warnings.warn(message, UserWarning) parsed_uri = parse_uri(uri) parsed_uri, transport_params = _consolidate_params(parsed_uri, transport_params) kwargs = smart_open.utils.check_kwargs(open, transport_params) return open(parsed_uri['bucket_id'], parsed_uri['key_id'], mode, **kwargs) def open( bucket_id, key_id, mode, version_id=None, buffer_size=DEFAULT_BUFFER_SIZE, min_part_size=DEFAULT_PART_SIZE, multipart_upload=True, defer_seek=False, client=None, client_kwargs=None, writebuffer=None, ): """Open an S3 object for reading or writing. Parameters ---------- bucket_id: str The name of the bucket this object resides in. key_id: str The name of the key within the bucket. mode: str The mode for opening the object. Must be either "rb" or "wb". buffer_size: int, optional The buffer size to use when performing I/O. min_part_size: int, optional The minimum part size for multipart uploads, in bytes. When the writebuffer contains this many bytes, smart_open will upload the bytes to S3 as a single part of a multi-part upload, freeing the buffer either partially or entirely. When you close the writer, it will assemble the parts together. The value determines the upper limit for the writebuffer. If buffer space is short (e.g. you are buffering to memory), then use a smaller value for min_part_size, or consider buffering to disk instead (see the writebuffer option). The value must be between 5MB and 5GB. If you specify a value outside of this range, smart_open will adjust it for you, because otherwise the upload _will_ fail. For writing only. Does not apply if you set multipart_upload=False. multipart_upload: bool, optional Default: `True` If set to `True`, will use multipart upload for writing to S3. If set to `False`, S3 upload will use the S3 Single-Part Upload API, which is more ideal for small file sizes. For writing only. version_id: str, optional Version of the object, used when reading object. If None, will fetch the most recent version. defer_seek: boolean, optional Default: `False` If set to `True` on a file opened for reading, GetObject will not be called until the first seek() or read(). Avoids redundant API queries when seeking before reading. client: object, optional The S3 client to use when working with boto3. If you don't specify this, then smart_open will create a new client for you. client_kwargs: dict, optional Additional parameters to pass to the relevant functions of the client. The keys are fully qualified method names, e.g. `S3.Client.create_multipart_upload`. The values are kwargs to pass to that method each time it is called. writebuffer: IO[bytes], optional By default, this module will buffer data in memory using io.BytesIO when writing. Pass another binary IO instance here to use it instead. For example, you may pass a file object to buffer to local disk instead of in RAM. Use this to keep RAM usage low at the expense of additional disk IO. If you pass in an open file, then you are responsible for cleaning it up after writing completes. """ logger.debug('%r', locals()) if mode not in constants.BINARY_MODES: raise NotImplementedError('bad mode: %r expected one of %r' % (mode, constants.BINARY_MODES)) if (mode == constants.WRITE_BINARY) and (version_id is not None): raise ValueError("version_id must be None when writing") if mode == constants.READ_BINARY: fileobj = Reader( bucket_id, key_id, version_id=version_id, buffer_size=buffer_size, defer_seek=defer_seek, client=client, client_kwargs=client_kwargs, ) elif mode == constants.WRITE_BINARY: if multipart_upload: fileobj = MultipartWriter( bucket_id, key_id, client=client, client_kwargs=client_kwargs, writebuffer=writebuffer, part_size=min_part_size, ) else: fileobj = SinglepartWriter( bucket_id, key_id, client=client, client_kwargs=client_kwargs, writebuffer=writebuffer, ) else: assert False, 'unexpected mode: %r' % mode fileobj.name = key_id return fileobj def _get(client, bucket, key, version, range_string): try: params = dict(Bucket=bucket, Key=key) if version: params["VersionId"] = version if range_string: params["Range"] = range_string return client.get_object(**params) except botocore.client.ClientError as error: wrapped_error = IOError( 'unable to access bucket: %r key: %r version: %r error: %s' % ( bucket, key, version, error ) ) wrapped_error.backend_error = error raise wrapped_error from error def _unwrap_ioerror(ioe): """Given an IOError from _get, return the 'Error' dictionary from boto.""" try: return ioe.backend_error.response['Error'] except (AttributeError, KeyError): return None class _SeekableRawReader(object): """Read an S3 object. This class is internal to the S3 submodule. """ def __init__( self, client, bucket, key, version_id=None, ): self._client = client self._bucket = bucket self._key = key self._version_id = version_id self._content_length = None self._position = 0 self._body = None def seek(self, offset, whence=constants.WHENCE_START): """Seek to the specified position. :param int offset: The offset in bytes. :param int whence: Where the offset is from. :returns: the position after seeking. :rtype: int """ if whence not in constants.WHENCE_CHOICES: raise ValueError('invalid whence, expected one of %r' % constants.WHENCE_CHOICES) # # Close old body explicitly. # When first seek() after __init__(), self._body is not exist. # if self._body is not None: self._body.close() self._body = None start = None stop = None if whence == constants.WHENCE_START: start = max(0, offset) elif whence == constants.WHENCE_CURRENT: start = max(0, offset + self._position) else: stop = max(0, -offset) # # If we can figure out that we've read past the EOF, then we can save # an extra API call. # if self._content_length is None: reached_eof = False elif start is not None and start >= self._content_length: reached_eof = True elif stop == 0: reached_eof = True else: reached_eof = False if reached_eof: self._body = io.BytesIO() self._position = self._content_length else: self._open_body(start, stop) return self._position def _open_body(self, start=None, stop=None): """Open a connection to download the specified range of bytes. Store the open file handle in self._body. If no range is specified, start defaults to self._position. start and stop follow the semantics of the http range header, so a stop without a start will read bytes beginning at stop. As a side effect, set self._content_length. Set self._position to self._content_length if start is past end of file. """ if start is None and stop is None: start = self._position range_string = smart_open.utils.make_range_string(start, stop) try: # Optimistically try to fetch the requested content range. response = _get( self._client, self._bucket, self._key, self._version_id, range_string, ) except IOError as ioe: # Handle requested content range exceeding content size. error_response = _unwrap_ioerror(ioe) if error_response is None or error_response.get('Code') != _OUT_OF_RANGE: raise try: self._position = self._content_length = int(error_response['ActualObjectSize']) self._body = io.BytesIO() except KeyError: response = _get( self._client, self._bucket, self._key, self._version_id, None, ) self._position = self._content_length = response["ContentLength"] self._body = response["Body"] else: # # Keep track of how many times boto3's built-in retry mechanism # activated. # # https://boto3.amazonaws.com/v1/documentation/api/latest/guide/retries.html#checking-retry-attempts-in-an-aws-service-response # logger.debug( '%s: RetryAttempts: %d', self, response['ResponseMetadata']['RetryAttempts'], ) # # range request may not always return partial content, see: # https://developer.mozilla.org/en-US/docs/Web/HTTP/Range_requests#partial_request_responses # status_code = response['ResponseMetadata']['HTTPStatusCode'] if status_code == http.HTTPStatus.PARTIAL_CONTENT: _, start, stop, length = smart_open.utils.parse_content_range(response['ContentRange']) self._position = start elif status_code == http.HTTPStatus.OK: length = response["ContentLength"] self._content_length = length self._body = response['Body'] def read(self, size=-1): """Read from the continuous connection with the remote peer.""" if self._body is None: # This is necessary for the very first read() after __init__(). self._open_body() if self._position >= self._content_length: return b'' # # Boto3 has built-in error handling and retry mechanisms: # # https://boto3.amazonaws.com/v1/documentation/api/latest/guide/error-handling.html # https://boto3.amazonaws.com/v1/documentation/api/latest/guide/retries.html # # Unfortunately, it isn't always enough. There is still a non-zero # possibility that an exception will slip past these mechanisms and # terminate the read prematurely. Luckily, at this stage, it's very # simple to recover from the problem: wait a little bit, reopen the # HTTP connection and try again. Usually, a single retry attempt is # enough to recover, but we try multiple times "just in case". # for attempt, seconds in enumerate([1, 2, 4, 8, 16], 1): try: if size == -1: binary = self._body.read() else: binary = self._body.read(size) except ( ConnectionResetError, botocore.exceptions.BotoCoreError, urllib3.exceptions.HTTPError, ) as err: logger.warning( '%s: caught %r while reading %d bytes, sleeping %ds before retry', self, err, size, seconds, ) time.sleep(seconds) self._open_body() else: self._position += len(binary) return binary raise IOError('%s: failed to read %d bytes after %d attempts' % (self, size, attempt)) def __str__(self): return 'smart_open.s3._SeekableReader(%r, %r)' % (self._bucket, self._key) def _initialize_boto3(rw, client, client_kwargs, bucket, key): """Created the required objects for accessing S3. Ideally, they have been already created for us and we can just reuse them.""" if client_kwargs is None: client_kwargs = {} if client is None: init_kwargs = client_kwargs.get('S3.Client', {}) client = boto3.client('s3', **init_kwargs) assert client rw._client = _ClientWrapper(client, client_kwargs) rw._bucket = bucket rw._key = key class Reader(io.BufferedIOBase): """Reads bytes from S3. Implements the io.BufferedIOBase interface of the standard library.""" def __init__( self, bucket, key, version_id=None, buffer_size=DEFAULT_BUFFER_SIZE, line_terminator=constants.BINARY_NEWLINE, defer_seek=False, client=None, client_kwargs=None, ): self._version_id = version_id self._buffer_size = buffer_size _initialize_boto3(self, client, client_kwargs, bucket, key) self._raw_reader = _SeekableRawReader( self._client, bucket, key, self._version_id, ) self._current_pos = 0 self._buffer = smart_open.bytebuffer.ByteBuffer(buffer_size) self._eof = False self._line_terminator = line_terminator self._seek_initialized = False # # This member is part of the io.BufferedIOBase interface. # self.raw = None if not defer_seek: self.seek(0) # # io.BufferedIOBase methods. # def close(self): """Flush and close this stream.""" logger.debug("close: called") pass def readable(self): """Return True if the stream can be read from.""" return True def read(self, size=-1): """Read up to size bytes from the object and return them.""" if size == 0: return b'' elif size < 0: # call read() before setting _current_pos to make sure _content_length is set out = self._read_from_buffer() + self._raw_reader.read() self._current_pos = self._raw_reader._content_length return out # # Return unused data first # if len(self._buffer) >= size: return self._read_from_buffer(size) # # If the stream is finished, return what we have. # if self._eof: return self._read_from_buffer() self._fill_buffer(size) return self._read_from_buffer(size) def read1(self, size=-1): """This is the same as read().""" return self.read(size=size) def readinto(self, b): """Read up to len(b) bytes into b, and return the number of bytes read.""" data = self.read(len(b)) if not data: return 0 b[:len(data)] = data return len(data) def readline(self, limit=-1): """Read up to and including the next newline. Returns the bytes read.""" if limit != -1: raise NotImplementedError('limits other than -1 not implemented yet') # # A single line may span multiple buffers. # line = io.BytesIO() while not (self._eof and len(self._buffer) == 0): line_part = self._buffer.readline(self._line_terminator) line.write(line_part) self._current_pos += len(line_part) if line_part.endswith(self._line_terminator): break else: self._fill_buffer() return line.getvalue() def seekable(self): """If False, seek(), tell() and truncate() will raise IOError. We offer only seek support, and no truncate support.""" return True def seek(self, offset, whence=constants.WHENCE_START): """Seek to the specified position. :param int offset: The offset in bytes. :param int whence: Where the offset is from. Returns the position after seeking.""" # Convert relative offset to absolute, since self._raw_reader # doesn't know our current position. if whence == constants.WHENCE_CURRENT: whence = constants.WHENCE_START offset += self._current_pos if not self._seek_initialized or not ( whence == constants.WHENCE_START and offset == self._current_pos ): self._current_pos = self._raw_reader.seek(offset, whence) self._buffer.empty() self._eof = self._current_pos == self._raw_reader._content_length self._seek_initialized = True return self._current_pos def tell(self): """Return the current position within the file.""" return self._current_pos def truncate(self, size=None): """Unsupported.""" raise io.UnsupportedOperation def detach(self): """Unsupported.""" raise io.UnsupportedOperation def terminate(self): """Do nothing.""" pass def to_boto3(self, resource): """Create an **independent** `boto3.s3.Object` instance that points to the same S3 object as this instance. Changes to the returned object will not affect the current instance. """ assert resource, 'resource must be a boto3.resource instance' obj = resource.Object(self._bucket, self._key) if self._version_id is not None: return obj.Version(self._version_id) else: return obj # # Internal methods. # def _read_from_buffer(self, size=-1): """Remove at most size bytes from our buffer and return them.""" size = size if size >= 0 else len(self._buffer) part = self._buffer.read(size) self._current_pos += len(part) return part def _fill_buffer(self, size=-1): size = max(size, self._buffer._chunk_size) while len(self._buffer) < size and not self._eof: bytes_read = self._buffer.fill(self._raw_reader) if bytes_read == 0: logger.debug('%s: reached EOF while filling buffer', self) self._eof = True def __str__(self): return "smart_open.s3.Reader(%r, %r)" % (self._bucket, self._key) def __repr__(self): return ( "smart_open.s3.Reader(" "bucket=%r, " "key=%r, " "version_id=%r, " "buffer_size=%r, " "line_terminator=%r)" ) % ( self._bucket, self._key, self._version_id, self._buffer_size, self._line_terminator, ) class MultipartWriter(io.BufferedIOBase): """Writes bytes to S3 using the multi part API. Implements the io.BufferedIOBase interface of the standard library.""" _upload_id = None # so `closed` property works in case __init__ fails and __del__ is called def __init__( self, bucket, key, part_size=DEFAULT_PART_SIZE, client=None, client_kwargs=None, writebuffer: io.BytesIO | None = None, ): adjusted_ps = smart_open.utils.clamp(part_size, MIN_PART_SIZE, MAX_PART_SIZE) if part_size != adjusted_ps: logger.warning(f"adjusting part_size from {part_size} to {adjusted_ps}") part_size = adjusted_ps self._part_size = part_size _initialize_boto3(self, client, client_kwargs, bucket, key) self._client: S3Client self._bucket: str self._key: str try: partial = functools.partial( self._client.create_multipart_upload, Bucket=bucket, Key=key, ) self._upload_id = RETRY._do(partial)['UploadId'] except botocore.client.ClientError as error: raise ValueError( 'the bucket %r does not exist, or is forbidden for access (%r)' % ( bucket, error ) ) from error if writebuffer is None: self._buf = io.BytesIO() else: self._buf = writebuffer self._total_bytes = 0 self._total_parts = 0 self._parts: list[dict[str, object]] = [] # # This member is part of the io.BufferedIOBase interface. # self.raw = None # type: ignore[assignment] def flush(self): pass # # Override some methods from io.IOBase. # def close(self): logger.debug("close: called") if self.closed: return if self._buf.tell(): self._upload_next_part() logger.debug('%s: completing multipart upload', self) if self._total_bytes and self._upload_id: partial = functools.partial( self._client.complete_multipart_upload, Bucket=self._bucket, Key=self._key, UploadId=self._upload_id, MultipartUpload={'Parts': self._parts}, ) RETRY._do(partial) logger.debug('%s: completed multipart upload', self) elif self._upload_id: # # AWS complains with "The XML you provided was not well-formed or # did not validate against our published schema" when the input is # completely empty => abort the upload, no file created. # # We work around this by creating an empty file explicitly. # self._client.abort_multipart_upload( Bucket=self._bucket, Key=self._key, UploadId=self._upload_id, ) self._client.put_object( Bucket=self._bucket, Key=self._key, Body=b'', ) logger.debug('%s: wrote 0 bytes to imitate multipart upload', self) self._upload_id = None @property def closed(self): return self._upload_id is None def writable(self): """Return True if the stream supports writing.""" return True def seekable(self): """If False, seek(), tell() and truncate() will raise IOError. We offer only tell support, and no seek or truncate support.""" return True def seek(self, offset, whence=constants.WHENCE_START): """Unsupported.""" raise io.UnsupportedOperation def truncate(self, size=None): """Unsupported.""" raise io.UnsupportedOperation def tell(self): """Return the current stream position.""" return self._total_bytes # # io.BufferedIOBase methods. # def detach(self): raise io.UnsupportedOperation("detach() not supported") def write(self, b: Buffer) -> int: """Write the given buffer (bytes, bytearray, memoryview or any buffer interface implementation) to the S3 file. For more information about buffers, see https://docs.python.org/3/c-api/buffer.html There's buffering happening under the covers, so this may not actually do any HTTP transfer right away.""" offset = 0 mv = memoryview(b) self._total_bytes += len(mv) # # botocore does not accept memoryview, otherwise we could've gotten # away with not needing to write a copy to the buffer aside from cases # where b is smaller than part_size # while offset < len(mv): start = offset end = offset + self._part_size - self._buf.tell() self._buf.write(mv[start:end]) if self._buf.tell() < self._part_size: # # Not enough data to write a new part just yet. The assert # ensures that we've consumed all of the input buffer. # assert end >= len(mv) return len(mv) self._upload_next_part() offset = end return len(mv) def terminate(self): """Cancel the underlying multipart upload.""" if self.closed: return logger.debug('%s: terminating multipart upload', self) self._client.abort_multipart_upload( Bucket=self._bucket, Key=self._key, UploadId=self._upload_id, ) self._upload_id = None logger.debug('%s: terminated multipart upload', self) def to_boto3(self, resource): """Create an **independent** `boto3.s3.Object` instance that points to the same S3 object as this instance. Changes to the returned object will not affect the current instance. """ assert resource, 'resource must be a boto3.resource instance' return resource.Object(self._bucket, self._key) # # Internal methods. # def _upload_next_part(self) -> None: part_num = self._total_parts + 1 logger.info( "%s: uploading part_num: %i, %i bytes (total %.3fGB)", self, part_num, self._buf.tell(), self._total_bytes / 1024.0 ** 3, ) self._buf.seek(0) # # Network problems in the middle of an upload are particularly # troublesome. We don't want to abort the entire upload just because # of a temporary connection problem, so this part needs to be # especially robust. # upload = RETRY._do( functools.partial( self._client.upload_part, Bucket=self._bucket, Key=self._key, UploadId=self._upload_id, PartNumber=part_num, Body=self._buf, ) ) self._parts.append({'ETag': upload['ETag'], 'PartNumber': part_num}) logger.debug("%s: upload of part_num #%i finished", self, part_num) self._total_parts += 1 self._buf.seek(0) self._buf.truncate(0) def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): if exc_type is not None: self.terminate() else: self.close() def __str__(self): return "smart_open.s3.MultipartWriter(%r, %r)" % (self._bucket, self._key) def __repr__(self): return "smart_open.s3.MultipartWriter(bucket=%r, key=%r, part_size=%r)" % ( self._bucket, self._key, self._part_size, ) class SinglepartWriter(io.BufferedIOBase): """Writes bytes to S3 using the single part API. Implements the io.BufferedIOBase interface of the standard library. This class buffers all of its input in memory until its `close` method is called. Only then will the data be written to S3 and the buffer is released.""" _buf = None # so `closed` property works in case __init__ fails and __del__ is called def __init__( self, bucket, key, client=None, client_kwargs=None, writebuffer=None, ): _initialize_boto3(self, client, client_kwargs, bucket, key) try: self._client.head_bucket(Bucket=bucket) except botocore.client.ClientError as e: raise ValueError('the bucket %r does not exist, or is forbidden for access' % bucket) from e if writebuffer is None: self._buf = io.BytesIO() else: self._buf = writebuffer self._total_bytes = 0 # # This member is part of the io.BufferedIOBase interface. # self.raw = None def flush(self): pass # # Override some methods from io.IOBase. # def close(self): logger.debug("close: called") if self.closed: return self._buf.seek(0) try: self._client.put_object( Bucket=self._bucket, Key=self._key, Body=self._buf, ) except botocore.client.ClientError as e: raise ValueError( 'the bucket %r does not exist, or is forbidden for access' % self._bucket) from e logger.debug("%s: direct upload finished", self) self._buf = None @property def closed(self): return self._buf is None def writable(self): """Return True if the stream supports writing.""" return True def seekable(self): """If False, seek(), tell() and truncate() will raise IOError. We offer only tell support, and no seek or truncate support.""" return True def seek(self, offset, whence=constants.WHENCE_START): """Unsupported.""" raise io.UnsupportedOperation def truncate(self, size=None): """Unsupported.""" raise io.UnsupportedOperation def tell(self): """Return the current stream position.""" return self._total_bytes # # io.BufferedIOBase methods. # def detach(self): raise io.UnsupportedOperation("detach() not supported") def write(self, b): """Write the given buffer (bytes, bytearray, memoryview or any buffer interface implementation) into the buffer. Content of the buffer will be written to S3 on close as a single-part upload. For more information about buffers, see https://docs.python.org/3/c-api/buffer.html""" length = self._buf.write(b) self._total_bytes += length return length def terminate(self): self._buf = None logger.debug('%s: terminated singlepart upload', self) # # Internal methods. # def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): if exc_type is not None: self.terminate() else: self.close() def __str__(self): return "smart_open.s3.SinglepartWriter(%r, %r)" % (self._bucket, self._key) def __repr__(self): return "smart_open.s3.SinglepartWriter(bucket=%r, key=%r)" % (self._bucket, self._key) def _accept_all(key): return True def iter_bucket( bucket_name, prefix='', accept_key=None, key_limit=None, workers=16, retries=3, **session_kwargs): """ Iterate and download all S3 objects under `s3://bucket_name/prefix`. Parameters ---------- bucket_name: str The name of the bucket. prefix: str, optional Limits the iteration to keys starting with the prefix. accept_key: callable, optional This is a function that accepts a key name (unicode string) and returns True/False, signalling whether the given key should be downloaded. The default behavior is to accept all keys. key_limit: int, optional If specified, the iterator will stop after yielding this many results. workers: int, optional The number of subprocesses to use. retries: int, optional The number of time to retry a failed download. session_kwargs: dict, optional Keyword arguments to pass when creating a new session. For a list of available names and values, see: https://boto3.amazonaws.com/v1/documentation/api/latest/reference/core/session.html#boto3.session.Session Yields ------ str The full key name (does not include the bucket name). bytes The full contents of the key. Notes ----- The keys are processed in parallel, using `workers` processes (default: 16), to speed up downloads greatly. If multiprocessing is not available, thus _MULTIPROCESSING is False, this parameter will be ignored. Examples -------- >>> # get all JSON files under "mybucket/foo/" >>> for key, content in iter_bucket( ... bucket_name, prefix='foo/', ... accept_key=lambda key: key.endswith('.json')): ... print key, len(content) >>> # limit to 10k files, using 32 parallel workers (default is 16) >>> for key, content in iter_bucket(bucket_name, key_limit=10000, workers=32): ... print key, len(content) """ if accept_key is None: accept_key = _accept_all # # If people insist on giving us bucket instances, silently extract the name # before moving on. Works for boto3 as well as boto. # try: bucket_name = bucket_name.name except AttributeError: pass total_size, key_no = 0, -1 key_iterator = _list_bucket( bucket_name, prefix=prefix, accept_key=accept_key, **session_kwargs) download_key = functools.partial( _download_key, bucket_name=bucket_name, retries=retries, **session_kwargs) with smart_open.concurrency.create_pool(processes=workers) as pool: result_iterator = pool.imap_unordered(download_key, key_iterator) key_no = 0 while True: try: (key, content) = result_iterator.__next__() if key_no % 1000 == 0: logger.info( "yielding key #%i: %s, size %i (total %.1fMB)", key_no, key, len(content), total_size / 1024.0 ** 2 ) yield key, content total_size += len(content) if key_limit is not None and key_no + 1 >= key_limit: # we were asked to output only a limited number of keys => we're done break except botocore.exceptions.ClientError as err: # # ignore 404 not found errors: they mean the object was deleted # after we listed the contents of the bucket, but before we # downloaded the object. # if not ('Error' in err.response and err.response['Error'].get('Code') == '404'): raise err except StopIteration: break key_no += 1 logger.info("processed %i keys, total size %i" % (key_no + 1, total_size)) def _list_bucket( bucket_name, prefix='', accept_key=lambda k: True, **session_kwargs): session = boto3.session.Session(**session_kwargs) client = session.client('s3') ctoken = None while True: # list_objects_v2 doesn't like a None value for ContinuationToken # so we don't set it if we don't have one. if ctoken: kwargs = dict(Bucket=bucket_name, Prefix=prefix, ContinuationToken=ctoken) else: kwargs = dict(Bucket=bucket_name, Prefix=prefix) response = client.list_objects_v2(**kwargs) try: content = response['Contents'] except KeyError: pass else: for c in content: key = c['Key'] if accept_key(key): yield key ctoken = response.get('NextContinuationToken', None) if not ctoken: break def _download_key(key_name, bucket_name=None, retries=3, **session_kwargs): if bucket_name is None: raise ValueError('bucket_name may not be None') # # https://boto3.amazonaws.com/v1/documentation/api/latest/guide/resources.html#multithreading-or-multiprocessing-with-resources # session = boto3.session.Session(**session_kwargs) s3 = session.resource('s3') bucket = s3.Bucket(bucket_name) # Sometimes, https://github.com/boto/boto/issues/2409 can happen # because of network issues on either side. # Retry up to 3 times to ensure its not a transient issue. for x in range(retries + 1): try: content_bytes = _download_fileobj(bucket, key_name) except botocore.client.ClientError: # Actually fail on last pass through the loop if x == retries: raise # Otherwise, try again, as this might be a transient timeout pass else: return key_name, content_bytes def _download_fileobj(bucket, key_name): # # This is a separate function only because it makes it easier to inject # exceptions during tests. # buf = io.BytesIO() bucket.download_fileobj(key_name, buf) return buf.getvalue()