Source code for apache_beam.io.azure.blobstoragefilesystem

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"""Azure Blob Storage Implementation for accesing files on
Azure Blob Storage.
"""

from apache_beam.io.azure import blobstorageio
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

__all__ = ['BlobStorageFileSystem']


[docs]class BlobStorageFileSystem(FileSystem): """An Azure Blob Storage ``FileSystem`` implementation for accesing files on Azure Blob Storage. """ CHUNK_SIZE = blobstorageio.MAX_BATCH_OPERATION_SIZE AZURE_FILE_SYSTEM_PREFIX = 'azfs://'
[docs] @classmethod def scheme(cls): """URI scheme for the FileSystem """ return 'azfs'
[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(BlobStorageFileSystem.AZURE_FILE_SYSTEM_PREFIX): raise ValueError( 'Basepath %r must be an Azure Blob Storage 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. For file-systems other than the local file-system, head should include the prefix. Args: path: path as a string Returns: a pair of path components as strings. """ path = path.strip() if not path.startswith(BlobStorageFileSystem.AZURE_FILE_SYSTEM_PREFIX): raise ValueError('Path %r must be Azure Blob Storage path.' % path) prefix_len = len(BlobStorageFileSystem.AZURE_FILE_SYSTEM_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 in \ blobstorageio.BlobStorageIO().list_prefix(dir_or_prefix).items(): yield FileMetadata(path, size) except Exception as e: # pylint: disable=broad-except raise BeamIOError("List operation failed", {dir_or_prefix: e}) 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 = blobstorageio.BlobStorageIO().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 read 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 """ if not len(source_file_names) == len(destination_file_names): message = 'Unable to copy unequal number of sources and destinations.' raise BeamIOError(message) src_dest_pairs = list(zip(source_file_names, destination_file_names)) return blobstorageio.BlobStorageIO().copy_paths(src_dest_pairs)
[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 """ if not len(source_file_names) == len(destination_file_names): message = 'Unable to rename unequal number of sources and destinations.' raise BeamIOError(message) src_dest_pairs = list(zip(source_file_names, destination_file_names)) results = blobstorageio.BlobStorageIO().rename_files(src_dest_pairs) # Retrieve exceptions. exceptions = {(src, dest): error for (src, dest, error) in results if error is not None} 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 """ try: return blobstorageio.BlobStorageIO().exists(path) except Exception as e: # pylint: disable=broad-except raise BeamIOError("Exists operation failed", {path: e})
[docs] def size(self, path): """Get size in bytes of a file on the FileSystem. Args: path: string filepath of file. Returns: int size of file according to the FileSystem. Raises: ``BeamIOError``: if path doesn't exist. """ try: return blobstorageio.BlobStorageIO().size(path) except Exception as e: # pylint: disable=broad-except raise BeamIOError("Size operation failed", {path: e})
[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. """ try: return blobstorageio.BlobStorageIO().last_updated(path) except Exception as e: # pylint: disable=broad-except raise BeamIOError("Last updated operation failed", {path: e})
[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 blobstorageio.BlobStorageIO().checksum(path) except Exception as e: # pylint: disable=broad-except raise BeamIOError("Checksum 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 Raises: ``BeamIOError``: if any of the delete operations fail """ results = blobstorageio.BlobStorageIO().delete_paths(paths) # Retrieve exceptions. exceptions = { path: error for (path, error) in results.items() if error is not None } if exceptions: raise BeamIOError("Delete operation failed", exceptions)