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from airflow.hooks.base_hook import BaseHook
from azure.datalake.store import core, lib, multithread
[docs]class AzureDataLakeHook(BaseHook):
"""
Interacts with Azure Data Lake.
Client ID and client secret should be in user and password parameters.
Tenant and account name should be extra field as
{"tenant": "<TENANT>", "account_name": "ACCOUNT_NAME"}.
:param azure_data_lake_conn_id: Reference to the Azure Data Lake connection.
:type azure_data_lake_conn_id: str
"""
def __init__(self, azure_data_lake_conn_id='azure_data_lake_default'):
self.conn_id = azure_data_lake_conn_id
self.connection = self.get_conn()
[docs] def get_conn(self):
"""Return a AzureDLFileSystem object."""
conn = self.get_connection(self.conn_id)
service_options = conn.extra_dejson
self.account_name = service_options.get('account_name')
adlCreds = lib.auth(tenant_id=service_options.get('tenant'),
client_secret=conn.password,
client_id=conn.login)
adlsFileSystemClient = core.AzureDLFileSystem(adlCreds,
store_name=self.account_name)
adlsFileSystemClient.connect()
return adlsFileSystemClient
[docs] def check_for_file(self, file_path):
"""
Check if a file exists on Azure Data Lake.
:param file_path: Path and name of the file.
:type file_path: str
:return: True if the file exists, False otherwise.
:rtype bool
"""
try:
files = self.connection.glob(file_path, details=False, invalidate_cache=True)
return len(files) == 1
except FileNotFoundError:
return False
[docs] def upload_file(self, local_path, remote_path, nthreads=64, overwrite=True,
buffersize=4194304, blocksize=4194304):
"""
Upload a file to Azure Data Lake.
:param local_path: local path. Can be single file, directory (in which case,
upload recursively) or glob pattern. Recursive glob patterns using `**`
are not supported.
:type local_path: str
:param remote_path: Remote path to upload to; if multiple files, this is the
dircetory root to write within.
:type remote_path: str
:param nthreads: Number of threads to use. If None, uses the number of cores.
:type nthreads: int
:param overwrite: Whether to forcibly overwrite existing files/directories.
If False and remote path is a directory, will quit regardless if any files
would be overwritten or not. If True, only matching filenames are actually
overwritten.
:type overwrite: bool
:param buffersize: int [2**22]
Number of bytes for internal buffer. This block cannot be bigger than
a chunk and cannot be smaller than a block.
:type buffersize: int
:param blocksize: int [2**22]
Number of bytes for a block. Within each chunk, we write a smaller
block for each API call. This block cannot be bigger than a chunk.
:type blocksize: int
"""
multithread.ADLUploader(self.connection,
lpath=local_path,
rpath=remote_path,
nthreads=nthreads,
overwrite=overwrite,
buffersize=buffersize,
blocksize=blocksize)
[docs] def download_file(self, local_path, remote_path, nthreads=64, overwrite=True,
buffersize=4194304, blocksize=4194304):
"""
Download a file from Azure Blob Storage.
:param local_path: local path. If downloading a single file, will write to this
specific file, unless it is an existing directory, in which case a file is
created within it. If downloading multiple files, this is the root
directory to write within. Will create directories as required.
:type local_path: str
:param remote_path: remote path/globstring to use to find remote files.
Recursive glob patterns using `**` are not supported.
:type remote_path: str
:param nthreads: Number of threads to use. If None, uses the number of cores.
:type nthreads: int
:param overwrite: Whether to forcibly overwrite existing files/directories.
If False and remote path is a directory, will quit regardless if any files
would be overwritten or not. If True, only matching filenames are actually
overwritten.
:type overwrite: bool
:param buffersize: int [2**22]
Number of bytes for internal buffer. This block cannot be bigger than
a chunk and cannot be smaller than a block.
:type buffersize: int
:param blocksize: int [2**22]
Number of bytes for a block. Within each chunk, we write a smaller
block for each API call. This block cannot be bigger than a chunk.
:type blocksize: int
"""
multithread.ADLDownloader(self.connection,
lpath=local_path,
rpath=remote_path,
nthreads=nthreads,
overwrite=overwrite,
buffersize=buffersize,
blocksize=blocksize)