Remove petastorm.hdfs

Author: Yevgeni Litvin

petastorm/fs_utils.py

@@ -17,9 +17,6 @@
 import six
 from six.moves.urllib.parse import urlparse
 
-from petastorm.gcsfs_helpers.gcsfs_wrapper import GCSFSWrapper
-from petastorm.hdfs.namenode import HdfsNamenodeResolver, HdfsConnector
-
 logger = logging.getLogger(__name__)
 
 
@@ -36,168 +33,6 @@ def get_dataset_path(parsed_url):
     return parsed_url.path
 
 
-class FilesystemResolver(object):
-    """Resolves a dataset URL, makes a connection via pyarrow, and provides a filesystem object."""
-
-    def __init__(self, dataset_url, hadoop_configuration=None, connector=HdfsConnector,
-                 hdfs_driver='libhdfs3', user=None, s3_config_kwargs=None):
-        """
-        Given a dataset URL and an optional hadoop configuration, parse and interpret the URL to
-        instantiate a pyarrow filesystem.
-
-        Interpretation of the URL ``scheme://hostname:port/path`` occurs in the following order:
-
-        1. If no ``scheme``, no longer supported, so raise an exception!
-        2. If ``scheme`` is ``file``, use local filesystem path.
-        3. If ``scheme`` is ``hdfs``:
-           a. Try the ``hostname`` as a namespace and attempt to connect to a name node.
-              1. If that doesn't work, try connecting directly to namenode ``hostname:port``.
-           b. If no host, connect to the default name node.
-        5. If ``scheme`` is ``s3``, use s3fs. The user must manually install s3fs before using s3
-        6. If ``scheme`` is ``gs``or ``gcs``, use gcsfs. The user must manually install gcsfs before using GCS
-        7. Fail otherwise.
-
-        :param dataset_url: The hdfs URL or absolute path to the dataset
-        :param hadoop_configuration: an optional hadoop configuration
-        :param connector: the HDFS connector object to use (ONLY override for testing purposes)
-        :param hdfs_driver: A string denoting the hdfs driver to use (if using a dataset on hdfs). Current choices are
-        libhdfs (java through JNI) or libhdfs3 (C++)
-        :param user: String denoting username when connecting to HDFS. None implies login user.
-        """
-        # Cache both the original URL and the resolved, urlparsed dataset_url
-        self._dataset_url = dataset_url
-        self._parsed_dataset_url = None
-        # Cache the instantiated filesystem object
-        self._filesystem = None
-
-        if isinstance(self._dataset_url, six.string_types):
-            self._parsed_dataset_url = urlparse(self._dataset_url)
-        else:
-            self._parsed_dataset_url = self._dataset_url
-
-        if not self._parsed_dataset_url.scheme:
-            # Case 1
-            raise ValueError('ERROR! A scheme-less dataset url ({}) is no longer supported. '
-                             'Please prepend "file://" for local filesystem.'.format(self._parsed_dataset_url.scheme))
-
-        elif self._parsed_dataset_url.scheme == 'file':
-            # Case 2: definitely local
-            self._filesystem = pyarrow.localfs
-            self._filesystem_factory = lambda: pyarrow.localfs
-
-        elif self._parsed_dataset_url.scheme == 'hdfs':
-
-            if hdfs_driver == 'libhdfs3':
-                # libhdfs3 does not do any namenode resolution itself so we do it manually. This is not necessary
-                # if using libhdfs
-
-                # Obtain singleton and force hadoop config evaluation
-                namenode_resolver = HdfsNamenodeResolver(hadoop_configuration)
-
-                # Since we can't tell for sure, first treat the URL as though it references a name service
-                if self._parsed_dataset_url.netloc:
-                    # Case 3a: Use the portion of netloc before any port, which doesn't get lowercased
-                    nameservice = self._parsed_dataset_url.netloc.split(':')[0]
-                    namenodes = namenode_resolver.resolve_hdfs_name_service(nameservice)
-                    if namenodes:
-                        self._filesystem = connector.connect_to_either_namenode(namenodes, user=user)
-                        self._filesystem_factory = lambda: connector.connect_to_either_namenode(namenodes, user=user)
-                    if self._filesystem is None:
-                        # Case 3a1: That didn't work; try the URL as a namenode host
-                        self._filesystem = connector.hdfs_connect_namenode(self._parsed_dataset_url, user=user)
-                        self._filesystem_factory = \
-                            lambda url=self._dataset_url, user=user: \
-                            connector.hdfs_connect_namenode(urlparse(url), user=user)
-                else:
-                    # Case 3b: No netloc, so let's try to connect to default namenode
-                    # HdfsNamenodeResolver will raise exception if it fails to connect.
-                    nameservice, namenodes = namenode_resolver.resolve_default_hdfs_service()
-                    filesystem = connector.connect_to_either_namenode(namenodes, user=user)
-                    self._filesystem_factory = lambda: connector.connect_to_either_namenode(namenodes, user=user)
-                    if filesystem is not None:
-                        # Properly replace the parsed dataset URL once default namenode is confirmed
-                        self._parsed_dataset_url = urlparse(
-                            'hdfs://{}{}'.format(nameservice, self._parsed_dataset_url.path))
-                        self._filesystem = filesystem
-            else:
-                self._filesystem = connector.hdfs_connect_namenode(self._parsed_dataset_url, hdfs_driver, user=user)
-                self._filesystem_factory = \
-                    lambda url=self._dataset_url, user=user: \
-                    connector.hdfs_connect_namenode(urlparse(url), hdfs_driver, user=user)
-
-        elif self._parsed_dataset_url.scheme in ('s3', 's3a', 's3n'):
-            # Case 5
-            # S3 support requires s3fs to be installed
-            try:
-                import s3fs
-            except ImportError:
-                raise ValueError('Must have s3fs installed in order to use datasets on s3. '
-                                 'Please install s3fs and try again.')
-
-            if not self._parsed_dataset_url.netloc:
-                raise ValueError('URLs must be of the form s3://bucket/path')
-
-            fs = s3fs.S3FileSystem(config_kwargs=s3_config_kwargs)
-            self._filesystem = fs
-            self._filesystem_factory = lambda: s3fs.S3FileSystem(
-                config_kwargs=s3_config_kwargs
-            )
-
-        elif self._parsed_dataset_url.scheme in ['gs', 'gcs']:
-            # Case 6
-            # GCS support requires gcsfs to be installed
-            try:
-                import gcsfs
-            except ImportError:
-                raise ValueError('Must have gcsfs installed in order to use datasets on GCS. '
-                                 'Please install gcsfs and try again.')
-
-            if not self._parsed_dataset_url.netloc:
-                raise ValueError('URLs must be of the form gs://bucket/path or gcs://bucket/path')
-
-            fs = gcsfs.GCSFileSystem()
-            self._filesystem = GCSFSWrapper(fs)
-            self._filesystem_factory = lambda: GCSFSWrapper(gcsfs.GCSFileSystem())
-
-        else:
-            # Case 7
-            raise ValueError('Unsupported scheme in dataset url {}. '
-                             'Currently, only "file" and "hdfs" are supported.'.format(self._parsed_dataset_url.scheme))
-
-    def parsed_dataset_url(self):
-        """
-        :return: The urlparse'd dataset_url
-        """
-        return self._parsed_dataset_url
-
-    def get_dataset_path(self):
-        """
-        The dataset path is different than the one in `_parsed_dataset_url` for some filesystems.
-        For example s3fs expects the bucket name to be included in the path and doesn't support
-        paths that start with a `/`
-        """
-        return get_dataset_path(self._parsed_dataset_url)
-
-    def filesystem(self):
-        """
-        :return: The pyarrow filesystem object
-        """
-        return self._filesystem
-
-    def filesystem_factory(self):
-        """
-        :return: A serializable function that can be used to recreate the filesystem
-        object; useful for providing access to the filesystem object on distributed
-        Spark executors.
-        """
-        return self._filesystem_factory
-
-    def __getstate__(self):
-        raise RuntimeError('Pickling FilesystemResolver is not supported as it may contain some '
-                           'a file-system instance objects that do not support pickling but do not have '
-                           'anti-pickling protection')
-
-
 def get_filesystem_and_path_or_paths(url_or_urls, hdfs_driver='libhdfs3', s3_config_kwargs=None):
     """
     Given a url or url list, return a tuple ``(filesystem, path_or_paths)``