Source code for apache_beam.io.gcp.gcsfilesystem

#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License 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.
#

"""GCS file system implementation for accessing files on GCS.

**Updates to the I/O connector code**

For any significant updates to this I/O connector, please consider involving
corresponding code reviewers mentioned in
https://github.com/apache/beam/blob/master/sdks/python/OWNERS
"""

# pytype: skip-file

from typing import BinaryIO  # pylint: disable=unused-import

from apache_beam.io.filesystem import BeamIOError
from apache_beam.io.filesystem import CompressedFile
from apache_beam.io.filesystem import CompressionTypes
from apache_beam.io.filesystem import FileMetadata
from apache_beam.io.filesystem import FileSystem
from apache_beam.io.gcp import gcsio

__all__ = ['GCSFileSystem']


[docs]class GCSFileSystem(FileSystem): """A GCS ``FileSystem`` implementation for accessing files on GCS. """ CHUNK_SIZE = gcsio.MAX_BATCH_OPERATION_SIZE # Chuck size in batch operations GCS_PREFIX = 'gs://' def __init__(self, pipeline_options): super().__init__(pipeline_options) self._pipeline_options = pipeline_options
[docs] @classmethod def scheme(cls): """URI scheme for the FileSystem """ return 'gs'
[docs] def join(self, basepath, *paths): """Join two or more pathname components for the filesystem Args: basepath: string path of the first component of the path paths: path components to be added Returns: full path after combining all the passed components """ if not basepath.startswith(GCSFileSystem.GCS_PREFIX): raise ValueError('Basepath %r must be GCS path.' % basepath) path = basepath for p in paths: path = path.rstrip('/') + '/' + p.lstrip('/') return path
[docs] def split(self, path): """Splits the given path into two parts. Splits the path into a pair (head, tail) such that tail contains the last component of the path and head contains everything up to that. Head will include the GCS prefix ('gs://'). Args: path: path as a string Returns: a pair of path components as strings. """ path = path.strip() if not path.startswith(GCSFileSystem.GCS_PREFIX): raise ValueError('Path %r must be GCS path.' % path) prefix_len = len(GCSFileSystem.GCS_PREFIX) last_sep = path[prefix_len:].rfind('/') if last_sep >= 0: last_sep += prefix_len if last_sep > 0: return (path[:last_sep], path[last_sep + 1:]) elif last_sep < 0: return (path, '') else: raise ValueError('Invalid path: %s' % path)
[docs] def mkdirs(self, path): """Recursively create directories for the provided path. Args: path: string path of the directory structure that should be created Raises: IOError: if leaf directory already exists. """ pass
[docs] def has_dirs(self): """Whether this FileSystem supports directories.""" return False
def _list(self, dir_or_prefix): """List files in a location. Listing is non-recursive, for filesystems that support directories. Args: dir_or_prefix: (string) A directory or location prefix (for filesystems that don't have directories). Returns: Generator of ``FileMetadata`` objects. Raises: ``BeamIOError``: if listing fails, but not if no files were found. """ try: for path, (size, updated) in self._gcsIO().list_files(dir_or_prefix, with_metadata=True): yield FileMetadata(path, size, updated) except Exception as e: # pylint: disable=broad-except raise BeamIOError("List operation failed", {dir_or_prefix: e}) def _gcsIO(self): return gcsio.GcsIO(pipeline_options=self._pipeline_options) def _path_open( self, path, mode, mime_type='application/octet-stream', compression_type=CompressionTypes.AUTO): """Helper functions to open a file in the provided mode. """ compression_type = FileSystem._get_compression_type(path, compression_type) mime_type = CompressionTypes.mime_type(compression_type, mime_type) raw_file = self._gcsIO().open(path, mode, mime_type=mime_type) if compression_type == CompressionTypes.UNCOMPRESSED: return raw_file return CompressedFile(raw_file, compression_type=compression_type)
[docs] def create( self, path, mime_type='application/octet-stream', compression_type=CompressionTypes.AUTO): # type: (...) -> BinaryIO """Returns a write channel for the given file path. Args: path: string path of the file object to be written to the system mime_type: MIME type to specify the type of content in the file object compression_type: Type of compression to be used for this object Returns: file handle with a close function for the user to use """ return self._path_open(path, 'wb', mime_type, compression_type)
[docs] def open( self, path, mime_type='application/octet-stream', compression_type=CompressionTypes.AUTO): # type: (...) -> BinaryIO """Returns a read channel for the given file path. Args: path: string path of the file object to be written to the system mime_type: MIME type to specify the type of content in the file object compression_type: Type of compression to be used for this object Returns: file handle with a close function for the user to use """ return self._path_open(path, 'rb', mime_type, compression_type)
[docs] def copy(self, source_file_names, destination_file_names): """Recursively copy the file tree from the source to the destination Args: source_file_names: list of source file objects that needs to be copied destination_file_names: list of destination of the new object Raises: ``BeamIOError``: if any of the copy operations fail """ err_msg = ( "source_file_names and destination_file_names should " "be equal in length") assert len(source_file_names) == len(destination_file_names), err_msg def _copy_path(source, destination): """Recursively copy the file tree from the source to the destination """ if not destination.startswith(GCSFileSystem.GCS_PREFIX): raise ValueError('Destination %r must be GCS path.' % destination) # Use copy_tree if the path ends with / as it is a directory if source.endswith('/'): self._gcsIO().copytree(source, destination) else: self._gcsIO().copy(source, destination) exceptions = {} for source, destination in zip(source_file_names, destination_file_names): try: _copy_path(source, destination) except Exception as e: # pylint: disable=broad-except exceptions[(source, destination)] = e if exceptions: raise BeamIOError("Copy operation failed", exceptions)
[docs] def rename(self, source_file_names, destination_file_names): """Rename the files at the source list to the destination list. Source and destination lists should be of the same size. Args: source_file_names: List of file paths that need to be moved destination_file_names: List of destination_file_names for the files Raises: ``BeamIOError``: if any of the rename operations fail """ err_msg = ( "source_file_names and destination_file_names should " "be equal in length") assert len(source_file_names) == len(destination_file_names), err_msg gcs_batches = [] gcs_current_batch = [] for src, dest in zip(source_file_names, destination_file_names): gcs_current_batch.append((src, dest)) if len(gcs_current_batch) == self.CHUNK_SIZE: gcs_batches.append(gcs_current_batch) gcs_current_batch = [] if gcs_current_batch: gcs_batches.append(gcs_current_batch) # Execute GCS renames if any and return exceptions. exceptions = {} for batch in gcs_batches: copy_statuses = self._gcsIO().copy_batch(batch) copy_succeeded = {} delete_targets = [] for src, dest, exception in copy_statuses: if exception: exceptions[(src, dest)] = exception else: copy_succeeded[src] = dest delete_targets.append(src) delete_statuses = self._gcsIO().delete_batch(delete_targets) for src, exception in delete_statuses: if exception: dest = copy_succeeded[src] exceptions[(src, dest)] = exception if exceptions: raise BeamIOError("Rename operation failed", exceptions)
[docs] def exists(self, path): """Check if the provided path exists on the FileSystem. Args: path: string path that needs to be checked. Returns: boolean flag indicating if path exists """ return self._gcsIO().exists(path)
[docs] def size(self, path): """Get size of path on the FileSystem. Args: path: string path in question. Returns: int size of path according to the FileSystem. Raises: ``BeamIOError``: if path doesn't exist. """ return self._gcsIO().size(path)
[docs] def last_updated(self, path): """Get UNIX Epoch time in seconds on the FileSystem. Args: path: string path of file. Returns: float UNIX Epoch time Raises: ``BeamIOError``: if path doesn't exist. """ return self._gcsIO().last_updated(path)
[docs] def checksum(self, path): """Fetch checksum metadata of a file on the :class:`~apache_beam.io.filesystem.FileSystem`. Args: path: string path of a file. Returns: string containing checksum Raises: ``BeamIOError``: if path isn't a file or doesn't exist. """ try: return self._gcsIO().checksum(path) except Exception as e: # pylint: disable=broad-except raise BeamIOError("Checksum operation failed", {path: e})
[docs] def metadata(self, path): """Fetch metadata fields of a file on the FileSystem. Args: path: string path of a file. Returns: :class:`~apache_beam.io.filesystem.FileMetadata`. Raises: ``BeamIOError``: if path isn't a file or doesn't exist. """ try: file_metadata = self._gcsIO()._status(path) return FileMetadata(path, file_metadata['size'], file_metadata['updated']) except Exception as e: # pylint: disable=broad-except raise BeamIOError("Metadata operation failed", {path: e})
[docs] def delete(self, paths): """Deletes files or directories at the provided paths. Directories will be deleted recursively. Args: paths: list of paths that give the file objects to be deleted """ exceptions = {} for path in paths: if path.endswith('/'): path_to_use = path + '*' else: path_to_use = path match_result = self.match([path_to_use])[0] statuses = self._gcsIO().delete_batch( [m.path for m in match_result.metadata_list]) for target, exception in statuses: if exception: exceptions[target] = exception if exceptions: raise BeamIOError("Delete operation failed", exceptions)