# -*- coding: utf-8 -*- # coding=utf-8 # -------------------------------------------------------------------------- # Copyright (c) Microsoft Corporation. All rights reserved. # Licensed under the MIT License. See License.txt in the project root for # license information. # -------------------------------------------------------------------------- """ High performance multi-threaded module to up/download Calls method in `core` with thread pool executor to ensure the network is used to its maximum throughput. Only implements upload and download of (massive) files and directory trees. """ from contextlib import closing import glob import logging import os import pickle import time import errno import uuid from io import open from .core import AzureDLPath, _fetch_range from .exceptions import FileExistsError, FileNotFoundError from .transfer import ADLTransferClient from .utils import datadir, read_block, tokenize from .retry import ExponentialRetryPolicy logger = logging.getLogger(__name__) def save(instance, filename, keep=True): if os.path.exists(filename): all_downloads = load(filename) else: all_downloads = {} if not instance.client._fstates.contains_all('finished') and keep: all_downloads[instance._name] = instance else: all_downloads.pop(instance._name, None) try: # persist failure should not halt things with open(filename, 'wb') as f: pickle.dump(all_downloads, f) except IOError: logger.debug("Persist failed: %s" % filename) def load(filename): try: return pickle.load(open(filename, 'rb')) except: return {} class ADLDownloader(object): """ Download remote file(s) using chunks and threads Launches multiple threads for efficient downloading, with `chunksize` assigned to each. The remote path can be a single file, a directory of files or a glob pattern. Parameters ---------- adlfs: ADL filesystem instance rpath: str remote path/globstring to use to find remote files. Recursive glob patterns using `**` are not supported. lpath: str 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. nthreads: int [None] Number of threads to use. If None, uses the number of cores. chunksize: int [2**28] Number of bytes for a chunk. Large files are split into chunks. Files smaller than this number will always be transferred in a single thread. buffersize: int [2**22] Ignored in curret implementation. Number of bytes for internal buffer. This block cannot be bigger than a chunk and cannot be smaller than a block. 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. client: ADLTransferClient [None] Set an instance of ADLTransferClient when finer-grained control over transfer parameters is needed. Ignores `nthreads` and `chunksize` set by constructor. run: bool [True] Whether to begin executing immediately. overwrite: bool [False] Whether to forcibly overwrite existing files/directories. If False and local path is a directory, will quit regardless if any files would be overwritten or not. If True, only matching filenames are actually overwritten. progress_callback: callable [None] Callback for progress with signature function(current, total) where current is the number of bytes transfered so far, and total is the size of the blob, or None if the total size is unknown. timeout: int (0) Default value 0 means infinite timeout. Otherwise time in seconds before the process will stop and raise an exception if transfer is still in progress See Also -------- azure.datalake.store.transfer.ADLTransferClient """ def __init__(self, adlfs, rpath, lpath, nthreads=None, chunksize=2**28, buffersize=2**22, blocksize=2**22, client=None, run=True, overwrite=False, verbose=False, progress_callback=None, timeout=0): # validate that the src exists and the current user has access to it # this only validates access to the top level folder. If there are files # or folders underneath it that the user does not have access to the download # will fail on those files. We clean the path in case there are wildcards. # In this case, we will always invalidate the cache for this check to # do our best to ensure that the path exists as close to run time of the transfer as possible. # Due to the nature of a distributed filesystem, the path could be deleted later during execution, # at which point the transfer's behavior may be non-deterministic, but it will indicate an error. if not adlfs.exists(AzureDLPath(rpath).globless_prefix, invalidate_cache=True): raise FileNotFoundError('Data Lake item at path: {} either does not exist or the current user does not have permission to access it.'.format(rpath)) if client: self.client = client else: self.client = ADLTransferClient( adlfs, transfer=get_chunk, nthreads=nthreads, chunksize=chunksize, buffersize=buffersize, blocksize=blocksize, chunked=False, verbose=verbose, parent=self, progress_callback=progress_callback, timeout=timeout) self._name = tokenize(adlfs, rpath, lpath, chunksize, blocksize) self.rpath = rpath self.lpath = lpath self._overwrite = overwrite existing_files = self._setup() if existing_files: raise FileExistsError('Overwrite was not specified and the following files exist, blocking the transfer operation. Please specify overwrite to overwrite these files during transfer: {}'.format(','.join(existing_files))) if run: self.run() def save(self, keep=True): """ Persist this download Saves a copy of this transfer process in its current state to disk. This is done automatically for a running transfer, so that as a chunk is completed, this is reflected. Thus, if a transfer is interrupted, e.g., by user action, the transfer can be restarted at another time. All chunks that were not already completed will be restarted at that time. See methods ``load`` to retrieved saved transfers and ``run`` to resume a stopped transfer. Parameters ---------- keep: bool (True) If True, transfer will be saved if some chunks remain to be completed; the transfer will be sure to be removed otherwise. """ save(self, os.path.join(datadir, 'downloads'), keep) @staticmethod def load(): """ Load list of persisted transfers from disk, for possible resumption. Returns ------- A dictionary of download instances. The hashes are auto- generated unique. The state of the chunks completed, errored, etc., can be seen in the status attribute. Instances can be resumed with ``run()``. """ return load(os.path.join(datadir, 'downloads')) @staticmethod def clear_saved(): """ Remove references to all persisted downloads. """ if os.path.exists(os.path.join(datadir, 'downloads')): os.remove(os.path.join(datadir, 'downloads')) @property def hash(self): return self._name def _setup(self): """ Create set of parameters to loop over """ def is_glob_path(path): path = AzureDLPath(path).trim() prefix = path.globless_prefix return not path == prefix is_rpath_glob = is_glob_path(self.rpath) if is_rpath_glob: rfiles = self.client._adlfs.glob(self.rpath, details=True, invalidate_cache=True) else: rfiles = self.client._adlfs.walk(self.rpath, details=True, invalidate_cache=True) if not rfiles: raise ValueError('No files to download') # If only one file is returned we are not sure whether user specified a dir or a file to download, # since walk gives the same result for both i.e walk("DirWithsingleFile") == walk("DirWithSingleFile\SingleFile) # If user specified a file in rpath, # then we want to download the file into lpath directly and not create another subdir for that. # If user specified a dir that happens to contain only one file, we want to create the dir as well under lpath. if len(rfiles) == 1 and not is_rpath_glob and self.client._adlfs.info(self.rpath)['type'] == 'FILE': if os.path.exists(self.lpath) and os.path.isdir(self.lpath): file_pairs = [(os.path.join(self.lpath, os.path.basename(rfiles[0]['name'] + '.inprogress')), rfiles[0])] else: file_pairs = [(self.lpath, rfiles[0])] else: local_rel_rpath = str(AzureDLPath(self.rpath).trim().globless_prefix) file_pairs = [(os.path.join(self.lpath, os.path.relpath(f['name'] +'.inprogress', local_rel_rpath)), f) for f in rfiles] # this property is used for internal validation # and should not be referenced directly by public callers self._file_pairs = file_pairs existing_files = [] for lfile, rfile in file_pairs: # only interested in the final destination file name for existence, # not the initial inprogress target destination_file = lfile.replace('.inprogress', '') if not self._overwrite and os.path.exists(destination_file): existing_files.append(destination_file) else: self.client.submit(rfile['name'], lfile, rfile['length']) return existing_files def run(self, nthreads=None, monitor=True): """ Populate transfer queue and execute downloads Parameters ---------- nthreads: int [None] Override default nthreads, if given monitor: bool [True] To watch and wait (block) until completion. """ def touch(self, src, dst): root = os.path.dirname(dst) if not os.path.exists(root) and root: # don't attempt to create current directory logger.debug('Creating directory %s', root) try: os.makedirs(root) except OSError as e: if e.errno != errno.EEXIST: raise logger.debug('Creating empty file %s', dst) with open(dst, 'wb'): pass for empty_directory in self.client._adlfs._empty_dirs_to_add(): local_rel_rpath = str(AzureDLPath(self.rpath).trim().globless_prefix) path = os.path.join(self.lpath, os.path.relpath(empty_directory['name'], local_rel_rpath)) try: os.makedirs(path) except OSError as e: if e.errno != errno.EEXIST: raise self.client.run(nthreads, monitor, before_start=touch) def active(self): """ Return whether the downloader is active """ return self.client.active def successful(self): """ Return whether the downloader completed successfully. It will raise AssertionError if the downloader is active. """ return self.client.successful def __str__(self): return " %s (%s)>" % (self.rpath, self.lpath, self.client.status) __repr__ = __str__ def get_chunk(adlfs, src, dst, offset, size, buffersize, blocksize, shutdown_event=None, retries=10, delay=0.01, backoff=3): """ Download a piece of a remote file and write locally Internal function used by `download`. """ err = None total_bytes_downloaded = 0 retry_policy = ExponentialRetryPolicy(max_retries=retries, exponential_retry_interval=delay, exponential_factor=backoff) filesessionid = str(uuid.uuid4()) try: nbytes = 0 start = offset with open(dst, 'rb+') as fout: fout.seek(start) while start < offset+size: with closing(_fetch_range(adlfs.azure, src, start=start, end=min(start+blocksize, offset+size), stream=True, retry_policy=retry_policy, filesessionid=filesessionid)) as response: chunk = response.content if shutdown_event and shutdown_event.is_set(): return total_bytes_downloaded, None if chunk: nwritten = fout.write(chunk) if nwritten: nbytes += nwritten start += nwritten else: raise IOError("Failed to write to disk for {0} at location {1} with blocksize {2}".format(dst, start, blocksize)) logger.debug('Downloaded %s bytes to %s, byte offset %s', nbytes, dst, offset) # There are certain cases where we will be throttled and recieve less than the expected amount of data. # In these cases, instead of failing right away, instead indicate a retry is occuring and update offset and # size to attempt another read to get the rest of the data. We will only do this if the amount of bytes read # is less than size, because if somehow we recieved too much data we are not clear on how to proceed. if nbytes < size: errMsg = 'Did not recieve total bytes requested from server. This can be due to server side throttling and will be retried. Data Expected: {}. Data Received: {}.'.format(size, nbytes) size -= nbytes offset += nbytes total_bytes_downloaded += nbytes raise IOError(errMsg) elif nbytes > size: raise IOError('Received more bytes than expected from the server. Expected: {}. Received: {}.'.format(size, nbytes)) else: total_bytes_downloaded += nbytes return total_bytes_downloaded, None except Exception as e: err = e logger.debug('Exception %s on ADL download on attempt', repr(err)) exception = RuntimeError('Max number of ADL retries exceeded: exception ' + repr(err)) logger.error('Download failed %s; %s', dst, repr(exception)) return total_bytes_downloaded, exception class ADLUploader(object): """ Upload local file(s) using chunks and threads Launches multiple threads for efficient uploading, with `chunksize` assigned to each. The path can be a single file, a directory of files or a glob pattern. Parameters ---------- adlfs: ADL filesystem instance rpath: str remote path to upload to; if multiple files, this is the dircetory root to write within lpath: str local path. Can be single file, directory (in which case, upload recursively) or glob pattern. Recursive glob patterns using `**` are not supported. nthreads: int [None] Number of threads to use. If None, uses the number of cores. chunksize: int [None] Number of bytes for a chunk. Large files are split into chunks. Files smaller than this number will always be transferred in a single thread. 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. 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. client: ADLTransferClient [None] Set an instance of ADLTransferClient when finer-grained control over transfer parameters is needed. Ignores `nthreads` and `chunksize` set by constructor. run: bool [True] Whether to begin executing immediately. overwrite: bool [False] 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. progress_callback: callable [None] Callback for progress with signature function(current, total) where current is the number of bytes transfered so far, and total is the size of the blob, or None if the total size is unknown. timeout: int (0) Default value 0 means infinite timeout. Otherwise time in seconds before the process will stop and raise an exception if transfer is still in progress See Also -------- azure.datalake.store.transfer.ADLTransferClient """ def __init__(self, adlfs, rpath, lpath, nthreads=None, chunksize=None, buffersize=2**22, blocksize=2**22, client=None, run=True, overwrite=False, verbose=False, progress_callback=None, timeout=0): if client: self.client = client else: self.client = ADLTransferClient( adlfs, transfer=put_chunk, nthreads=nthreads, chunksize=None, buffersize=buffersize, blocksize=blocksize, chunked=False, delimiter=None, # TODO: see utils.cs for what is required to support delimiters. parent=self, verbose=verbose, unique_temporary=True, progress_callback=progress_callback, timeout=timeout) self._name = tokenize(adlfs, rpath, lpath, chunksize, blocksize) self.rpath = AzureDLPath(rpath) self.lpath = lpath self._overwrite = overwrite existing_files = self._setup() if existing_files: raise FileExistsError('Overwrite was not specified and the following files exist, blocking the transfer operation. Please specify overwrite to overwrite these files during transfer: {}'.format(','.join(existing_files))) if run: self.run() def save(self, keep=True): """ Persist this upload Saves a copy of this transfer process in its current state to disk. This is done automatically for a running transfer, so that as a chunk is completed, this is reflected. Thus, if a transfer is interrupted, e.g., by user action, the transfer can be restarted at another time. All chunks that were not already completed will be restarted at that time. See methods ``load`` to retrieved saved transfers and ``run`` to resume a stopped transfer. Parameters ---------- keep: bool (True) If True, transfer will be saved if some chunks remain to be completed; the transfer will be sure to be removed otherwise. """ save(self, os.path.join(datadir, 'uploads'), keep) @staticmethod def load(): """ Load list of persisted transfers from disk, for possible resumption. Returns ------- A dictionary of upload instances. The hashes are auto generated unique. The state of the chunks completed, errored, etc., can be seen in the status attribute. Instances can be resumed with ``run()``. """ return load(os.path.join(datadir, 'uploads')) @staticmethod def clear_saved(): """ Remove references to all persisted uploads. """ if os.path.exists(os.path.join(datadir, 'uploads')): os.remove(os.path.join(datadir, 'uploads')) @property def hash(self): return self._name def _setup(self): """ Create set of parameters to loop over """ is_path_walk_empty = False if "*" not in self.lpath: lfiles = [] for directory, subdir, fnames in os.walk(self.lpath): lfiles.extend([os.path.join(directory, f) for f in fnames]) if not subdir and not fnames: # Empty Directory self.client._adlfs._emptyDirs.append(directory) if (not lfiles and os.path.exists(self.lpath) and not os.path.isdir(self.lpath)): lfiles = [self.lpath] is_path_walk_empty = True else: lfiles = glob.glob(self.lpath) if len(lfiles) > 0 and not is_path_walk_empty: local_rel_lpath = str(AzureDLPath(self.lpath).globless_prefix) file_pairs = [(f, self.rpath / AzureDLPath(f).relative_to(local_rel_lpath)) for f in lfiles] elif lfiles: if self.client._adlfs.exists(self.rpath, invalidate_cache=True) and \ self.client._adlfs.info(self.rpath, invalidate_cache=False)['type'] == "DIRECTORY": file_pairs = [(lfiles[0], self.rpath / AzureDLPath(lfiles[0]).name)] else: file_pairs = [(lfiles[0], self.rpath)] else: raise ValueError('No files to upload') # this property is used for internal validation # and should not be referenced directly by public callers self._file_pairs = file_pairs existing_files = [] for lfile, rfile in file_pairs: if not self._overwrite and self.client._adlfs.exists(rfile, invalidate_cache=False): existing_files.append(rfile.as_posix()) else: fsize = os.stat(lfile).st_size self.client.submit(lfile, rfile, fsize) return existing_files def run(self, nthreads=None, monitor=True): """ Populate transfer queue and execute downloads Parameters ---------- nthreads: int [None] Override default nthreads, if given monitor: bool [True] To watch and wait (block) until completion. """ for empty_directory in self.client._adlfs._empty_dirs_to_add(): local_rel_path = os.path.relpath(empty_directory, self.lpath) rel_rpath = str(AzureDLPath(self.rpath).trim().globless_prefix / local_rel_path) self.client._adlfs.mkdir(rel_rpath) self.client.run(nthreads, monitor) def active(self): """ Return whether the uploader is active """ return self.client.active def successful(self): """ Return whether the uploader completed successfully. It will raise AssertionError if the uploader is active. """ return self.client.successful def __str__(self): return " %s (%s)>" % (self.lpath, self.rpath, self.client.status) __repr__ = __str__ def put_chunk(adlfs, src, dst, offset, size, buffersize, blocksize, delimiter=None, shutdown_event=None): """ Upload a piece of a local file Internal function used by `upload`. """ nbytes = 0 try: with adlfs.open(dst, 'wb', blocksize=buffersize, delimiter=delimiter) as fout: end = offset + size miniblock = min(size, blocksize) # For empty files there is no need to take the IO hit. if size != 0: with open(src, 'rb') as fin: for o in range(offset, end, miniblock): if shutdown_event and shutdown_event.is_set(): return nbytes, None data = read_block(fin, o, miniblock, delimiter) nbytes += fout.write(data) except Exception as e: exception = repr(e) logger.error('Upload failed %s; %s', src, exception) return nbytes, exception logger.debug('Uploaded from %s, byte offset %s', src, offset) return nbytes, None