fs.py

# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed 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.

import os
import multiprocessing

import re
import time
import six
import abc
from paddle.fluid import core
import functools

import shutil

__all__ = []


class ExecuteError(Exception):
    pass


class FSFileExistsError(Exception):
    pass


class FSFileNotExistsError(Exception):
    pass


class FSTimeOut(Exception):
    pass


class FSShellCmdAborted(ExecuteError):
    pass


class FS(object):

    @abc.abstractmethod
    def ls_dir(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def is_file(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def is_dir(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def is_exist(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def upload(self, local_path, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def download(self, fs_path, local_path):
        raise NotImplementedError

    @abc.abstractmethod
    def mkdirs(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def delete(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def need_upload_download(self):
        raise NotImplementedError

    @abc.abstractmethod
    def rename(self, fs_src_path, fs_dst_path):
        raise NotImplementedError

    @abc.abstractmethod
    def mv(self, fs_src_path, fs_dst_path, overwrite=False, test_exists=False):
        raise NotImplementedError

    @abc.abstractmethod
    def upload_dir(self, local_dir, dest_dir):
        raise NotImplementedError

    @abc.abstractmethod
    def list_dirs(self, fs_path):
        raise NotImplementedError

    @abc.abstractmethod
    def touch(self, fs_path, exist_ok=True):
        raise NotImplementedError

    @abc.abstractmethod
    def cat(self, fs_path=None):
        raise NotImplementedError


class LocalFS(FS):
    """
    A tool of local file system.

    Examples:
        .. code-block:: python

            from paddle.distributed.fleet.utils import LocalFS

            client = LocalFS()
            subdirs, files = client.ls_dir("./")
    """

    def ls_dir(self, fs_path):
        """
        List directorys and files under `fs_path` .

        Args:
            fs_path(str): The local file path.

        Returns:
            Tuple: Return a 2-tuple, the first is a list of all its subdirectories,
            and the second is a list of all its subfiles, e.g. ([subdirname1, subdirname1, ...], [filename1, filename2, ...]).

        Examples:
            .. code-block:: python

                from paddle.distributed.fleet.utils import LocalFS

                client = LocalFS()
                subdirs, files = client.ls_dir("./")
        """
        if not self.is_exist(fs_path):
            return [], []

        dirs = []
        files = []
        for f in os.listdir(fs_path):
            if os.path.isdir(fs_path + "/" + f):
                dirs.append(f)
            else:
                files.append(f)

        return dirs, files

    def mkdirs(self, fs_path):
        """
        Create a local directory.

        Args:
            fs_path(str): The local directory path.

        Examples:
            .. code-block:: python

                from paddle.distributed.fleet.utils import LocalFS

                client = LocalFS()
                client.mkdirs("test_mkdirs")
                client.delete("test_mkdirs")
        """
        assert not os.path.isfile(fs_path), "{} is already a file".format(
            fs_path)
        os.system("mkdir -p {}".format(fs_path))

    def rename(self, fs_src_path, fs_dst_path):
        """
        Rename the file.

        Args:
            fs_src_path(str): The actual name of the file or directory
            fs_dst_path(str): The new name of the file or directory.

        Examples:
            .. code-block:: python

                from paddle.distributed.fleet.utils import LocalFS

                client = LocalFS()
                client.touch("test_rename_src")
                print(client.is_exists("test_rename_src")) # True
                client.rename("test_rename_src", "test_rename_dst")
                print(client.is_exists("test_rename_src")) # False
                print(client.is_exists("test_rename_dst")) # True
                client.delete("test_rename_dst")
        """
        os.rename(fs_src_path, fs_dst_path)

    def _rmr(self, fs_path):
        shutil.rmtree(fs_path)

    def _rm(self, fs_path):
        os.remove(fs_path)

    def delete(self, fs_path):
        """
        Delete the local file path, whether it's a file or directory.

        Args:
            fs_path(str): The local file path.

        Examples:
            .. code-block:: python

                from paddle.distributed.fleet.utils import LocalFS

                client = LocalFS()
                client.mkdirs("test_localFS_mkdirs")
                client.delete("test_localFS_mkdirs")
        """
        if not self.is_exist(fs_path):
            return

        if os.path.isfile(fs_path):
            return self._rm(fs_path)

        return self._rmr(fs_path)

    def need_upload_download(self):
        return False

    def is_file(self, fs_path):
        """
        Whether the local file path is a file.

        Args:
            fs_path(str): The local file path.

        Returns:
            Bool: Return true if the path exists and it's a file, otherwise return false.

        Examples:
            .. code-block:: python

                from paddle.distributed.fleet.utils import LocalFS

                client = LocalFS()
                client.touch("test_is_file")
                print(client.is_file("test_is_file")) # True
                client.delete("test_is_file")
        """
        return os.path.isfile(fs_path)

    def is_dir(self, fs_path):
        """
        Whether the local file path is a directory.

        Args:
            fs_path(str): The local file path.

        Returns:
            Bool: Return true if the path exists and it's a directory, otherwise return false.

        Examples:
            .. code-block:: python

                from paddle.distributed.fleet.utils import LocalFS

                client = LocalFS()
                client.mkdirs("test_is_dir")
                print(client.is_dir("test_is_file")) # True
                client.delete("test_is_dir")
        """
        return os.path.isdir(fs_path)

    def is_exist(self, fs_path):
        """
        Whether the local file path exists.

        Args:
            fs_path(str): The local file path.

        Returns:
            Bool: Wheter it's a file or directory, return true if the path exists,
            otherwise return false.

        Examples:
            .. code-block:: python

                from paddle.distributed.fleet.utils import LocalFS

                client = LocalFS()
                ret = local_fs.is_exist("test_is_exist")
        """
        return os.path.exists(fs_path)

    def touch(self, fs_path, exist_ok=True):
        """
        Create a local file.

        Args:
            fs_path(str): The local file path.
            exist_ok(bool): When `fs_path` exists, if `exist_ok` is set false,
            program will throw an Exception. Default is true.

        Examples:
            .. code-block:: python

                from paddle.distributed.fleet.utils import LocalFS

                client = LocalFS()
                client.touch("test_touch")
                client.delete("test_touch")
        """
        if self.is_exist(fs_path):
            if exist_ok:
                return
            raise FSFileExistsError

        os.system("touch {}".format(fs_path))

    def mv(self, src_path, dst_path, overwrite=False, test_exists=False):
        """
        Move a local file or directory from `src_path` to `dst_path` .

        Args:
            src_path(str):  Name of the file or directory, that's needed to be moved.
            dst_path(str):  Name of the file or directory to which to move to.
            overwrite(bool): Whether to re-write `dst_path` if that exists. Default is False.

        Examples:
            .. code-block:: python

                from paddle.distributed.fleet.utils import LocalFS

                client = LocalFS()
                client.touch("test_mv_src")
                client.mv("test_mv_src", "test_mv_dst")
                client.delete("test_mv_dst")
        """
        if not self.is_exist(src_path):
            raise FSFileNotExistsError

        if overwrite and self.is_exist(dst_path):
            self.delete(dst_path)

        if self.is_exist(dst_path):
            raise FSFileExistsError

        return self.rename(src_path, dst_path)

    def list_dirs(self, fs_path):
        """
        Only list directorys under `fs_path` .

        Args:
            fs_path(str): The local file path.

        Returns:
            List: A list of all its subdirectories, e.g. [subdirname1, subdirname1, ...].

        Examples:
            .. code-block:: python

                from paddle.distributed.fleet.utils import LocalFS

                client = LocalFS()
                subdirs = client.list_dirs("./")
        """
        if not self.is_exist(fs_path):
            return []

        dirs = [
            f for f in os.listdir(fs_path) if os.path.isdir(fs_path + "/" + f)
        ]

        return dirs


def _handle_errors(max_time_out=None):

    def decorator(f):

        @functools.wraps(f)
        def handler(*args, **kwargs):
            o = args[0]
            time_out = max_time_out
            if time_out is None:
                time_out = float(o._time_out) / 1000.0
            else:
                time_out /= 1000.0
            inter = float(o._sleep_inter) / 1000.0

            start = time.time()
            last_print_time = start
            while True:
                try:
                    return f(*args, **kwargs)
                # important: only ExecuteError need to retry
                except ExecuteError as e:
                    if time.time() - start >= time_out:
                        raise FSTimeOut("args:{} timeout:{}".format(
                            args,
                            time.time() - start))

                    time.sleep(inter)

                if time.time() - last_print_time > 30:
                    print("hadoop operator timeout:args:{} timeout:{}".format(
                        args,
                        time.time() - start))
                    last_print_time = time.time()

        return handler

    return decorator


class HDFSClient(FS):
    """
    A tool of HDFS.

    Args:
        hadoop_home(str): Hadoop home.
        configs(dict): Hadoop config. It is a dictionary and needs to contain the
            keys: "fs.default.name" and "hadoop.job.ugi".

    Examples:

        .. code-block:: text

            from paddle.distributed.fleet.utils import HDFSClient
            hadoop_home = "/home/client/hadoop-client/hadoop/"

            configs = {
                "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                "hadoop.job.ugi": "hello,hello123"
            }

            client = HDFSClient(hadoop_home, configs)
            client.ls_dir("hdfs:/test_hdfs_client")
    """

    def __init__(
            self,
            hadoop_home,
            configs,
            time_out=5 * 60 * 1000,  # ms
            sleep_inter=1000):  # ms
        self.pre_commands = []
        hadoop_bin = '%s/bin/hadoop' % hadoop_home
        self.pre_commands.append(hadoop_bin)
        dfs = 'fs'
        self.pre_commands.append(dfs)

        if configs:
            for k, v in six.iteritems(configs):
                config_command = '-D%s=%s' % (k, v)
                self.pre_commands.append(config_command)

        self._time_out = time_out
        self._sleep_inter = sleep_inter
        self._base_cmd = " ".join(self.pre_commands)
        self._bd_err_re = re.compile(
            r'\s?responseErrorMsg\s?\:.*, errorCode\:\s?[0-9]+, path\:')

    def _run_cmd(self, cmd, redirect_stderr=False, retry_times=5):
        exe_cmd = "{} -{}".format(self._base_cmd, cmd)
        ret = 0
        output = None
        retry_sleep_second = 3
        for x in range(retry_times + 1):
            ret, output = core.shell_execute_cmd(exe_cmd, 0, 0, redirect_stderr)
            ret = int(ret)
            if ret == 0:
                break
            time.sleep(retry_sleep_second)
        if ret == 134:
            raise FSShellCmdAborted(cmd)

        return ret, output.splitlines()

    @_handle_errors()
    def list_dirs(self, fs_path):
        """
        Only list directorys under `fs_path` .

        Args:
            fs_path(str): The HDFS file path.

        Returns:
            List: A list of all its subdirectories, e.g. [subdirname1, subdirname1, ...].

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                subdirs = client.list_dirs("hdfs:/test_hdfs_client")
        """
        if not self.is_exist(fs_path):
            return []

        dirs, files = self._ls_dir(fs_path)
        return dirs

    @_handle_errors()
    def ls_dir(self, fs_path):
        """
        List directorys and files under `fs_path` .

        Args:
            fs_path(str): The HDFS file path.

        Returns:
            Tuple: Return a 2-tuple, the first element is the list of all its subdirectories,
            and the second one is the list of all its subfiles, e.g. ([subdirname1, subdirname1, ...], [filename1, filename2, ...]).

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                subdirs, files = client.ls_dir("hdfs:/test_hdfs_client")
        """
        if not self.is_exist(fs_path):
            return [], []

        return self._ls_dir(fs_path)

    def _ls_dir(self, fs_path):
        cmd = "ls {}".format(fs_path)
        ret, lines = self._run_cmd(cmd)

        if ret != 0:
            raise ExecuteError(cmd)

        dirs = []
        files = []
        for line in lines:
            arr = line.split()
            if len(arr) != 8:
                continue

            p = os.path.basename(arr[7])
            if arr[0][0] == 'd':
                dirs.append(p)
            else:
                files.append(p)

        return dirs, files

    def _test_match(self, lines):
        for l in lines:
            m = self._bd_err_re.match(l)
            if m != None:
                return m

        return None

    @_handle_errors()
    def is_dir(self, fs_path):
        """
        Whether the remote HDFS path is a directory.

        Args:
            fs_path(str): The HDFS file path.

        Returns:
            Bool: Return true if the path exists and it's a directory, otherwise return false.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                ret = client.is_file("hdfs:/test_hdfs_client")
        """
        if not self.is_exist(fs_path):
            return False

        return self._is_dir(fs_path)

    def _is_dir(self, fs_path):
        cmd = "test -d {}".format(fs_path, redirect_stderr=True)
        ret, lines = self._run_cmd(cmd, retry_times=1)
        if ret:
            # other error
            if self._test_match(lines):
                print('raise exception: ')
                print('\n'.join(lines))
                raise ExecuteError(cmd)

            return False

        return True

    def is_file(self, fs_path):
        """
        Whether the remote HDFS path is a file.

        Args:
            fs_path(str): The HDFS file path.

        Returns:
            Bool: Return true if the path exists and it's a file, otherwise return false.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                ret = client.is_file("hdfs:/test_hdfs_client")
        """
        if not self.is_exist(fs_path):
            return False

        return not self._is_dir(fs_path)

    @_handle_errors()
    def is_exist(self, fs_path):
        """
        Whether the remote HDFS path exists.

        Args:
            fs_path(str): The hdfs file path.

        Returns:
            Bool: Whether it's is file or directory, return true if the path exists,
            otherwise return false.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                ret = client.is_exist("hdfs:/test_hdfs_client")
        """
        cmd = "test -e {} ".format(fs_path)
        ret, out = self._run_cmd(cmd, redirect_stderr=True, retry_times=1)
        if ret != 0:
            return False

        return True

    def upload_dir(self, local_dir, dest_dir, overwrite=False):
        """
        upload dir to hdfs
        Args:
            local_dir(str): local dir
            dest_dir(str): hdfs dest dir
            overwrite(bool): is overwrite
        Returns:
            return code
        """
        local_dir = local_dir.rstrip("/")
        dest_dir = dest_dir.rstrip("/")
        local_basename = os.path.basename(local_dir)
        if self.is_exist(dest_dir + "/" + local_basename) and overwrite:
            self.delete(dest_dir + "/" + local_basename)
        if not self.is_exist(dest_dir):
            self.mkdirs(dest_dir)
        self._try_upload(local_dir, dest_dir)

    # can't retry
    def upload(self, local_path, fs_path, multi_processes=5, overwrite=False):
        """
        Upload the local path to remote HDFS.

        Args:
            local_path(str): The local path.
            fs_path(str): The HDFS path.
            multi_processes(int|1): the upload data process at the same time, default=5
            overwrite(bool|False): will overwrite file on HDFS or not

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                client.upload("test_hdfs_client", "hdfs:/test_hdfs_client")
        """

        def __subprocess_upload(hdfs_path_single, datas):
            for data in datas:
                self._try_upload(data, hdfs_path_single)

        def get_local_files(path):
            """
            get local files
            Args:
                path(str): local path
            Returns:
                list of local files
            """
            rlist = []

            if not os.path.exists(path):
                return rlist

            if os.path.isdir(path):
                for file in os.listdir(path):
                    t = os.path.join(path, file)
                    rlist.append(t)
            else:
                rlist.append(path)
            return rlist

        local = LocalFS()
        if not local.is_exist(local_path):
            raise FSFileNotExistsError("{} not exists".format(local_path))

        all_files = get_local_files(local_path)
        if not all_files:
            print("there are nothing need to upload, function exit")
            return

        if self.is_exist(fs_path) and overwrite:
            self.delete(fs_path)
            self.mkdirs(fs_path)

        procs = []
        for i in range(multi_processes):
            process_datas = self._split_files(all_files, i, multi_processes)
            p = multiprocessing.Process(target=__subprocess_upload,
                                        args=(fs_path, process_datas))
            procs.append(p)
            p.start()

        # complete the processes
        for proc in procs:
            proc.join()

    @_handle_errors()
    def _try_upload(self, local_path, fs_path):
        cmd = "put {} {}".format(local_path, fs_path)
        ret = 0
        try:
            ret, _ = self._run_cmd(cmd)
            if ret != 0:
                raise ExecuteError(cmd)
        except Exception as e:
            self.delete(fs_path)
            raise e

    # can't retry
    def download(self, fs_path, local_path, multi_processes=5, overwrite=False):
        """
        Download remote HDFS path to the local.

        Args:
            fs_path(str):  The HDFS path.
            local_path(str): The local path.
            multi_processes(int|1): the download data process at the same time, default=1
            overwrite(bool): is overwrite

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                client.download("hdfs:/test_hdfs_client", "./")
        """

        def __subprocess_download(local_path, datas):
            """
            download file from HDFS
            Args:
                local_path(str): the local file path
                datas(str): the hdfs file path list
            """
            for data in datas:
                self._try_download(data, local_path)

        if not self.is_exist(fs_path):
            raise FSFileNotExistsError("{} not exits".format(fs_path))
        # download file
        if self.is_file(fs_path):
            return self._try_download(fs_path, local_path)
        # download dir
        dirs, all_filenames = self.ls_dir(fs_path)
        all_files = [fs_path + "/" + i for i in all_filenames]
        all_files.extend([fs_path + "/" + i for i in dirs])
        procs = []
        for i in range(multi_processes):
            process_datas = self._split_files(all_files, i, multi_processes)
            p = multiprocessing.Process(target=__subprocess_download,
                                        args=(local_path, process_datas))
            procs.append(p)
            p.start()

        # complete the processes
        for proc in procs:
            proc.join()

    @_handle_errors()
    def _try_download(self, fs_path, local_path):
        cmd = "get {} {}".format(fs_path, local_path)
        ret = 0
        try:
            ret, _ = self._run_cmd(cmd)
            if ret != 0:
                raise ExecuteError(cmd)
        except Exception as e:
            local_fs = LocalFS()
            local_fs.delete(local_path)
            raise e

    @_handle_errors()
    def mkdirs(self, fs_path):
        """
        Create a remote HDFS directory.

        Args:
            fs_path(str): The HDFS directory path.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                client.mkdirs("hdfs:/test_hdfs_client")
        """
        if self.is_exist(fs_path):
            return

        out_hdfs = False

        cmd = "mkdir {} ".format(fs_path)
        ret, out = self._run_cmd(cmd, redirect_stderr=True)
        if ret != 0:
            for l in out:
                if "No such file or directory" in l:
                    out_hdfs = True
                    break
            if not out_hdfs:
                raise ExecuteError(cmd)

        if out_hdfs and not self.is_exist(fs_path):
            cmd = "mkdir -p {}".format(fs_path)
            ret, _ = self._run_cmd(cmd)
            if ret != 0:
                raise ExecuteError(cmd)

    def mv(self, fs_src_path, fs_dst_path, overwrite=False, test_exists=True):
        """
        Move a remote HDFS file or directory from `fs_src_path` to `fs_dst_path` .

        Args:
            fs_src_path(str):  Name of the file or directory, that's needed to be moved.
            fs_dst_path(str):  Name of the file or directory to which to move to.
            overwrite(bool): Whether to re-write `fs_dst_path` if that exists. Default is False.
            test_exists(bool): Check the existence of `fs_src_path` and `fs_dst_path` . When `test_exists` is set true, if `fs_src_path` doesn't exist or `fs_dst_path` exists, program will throw an Excetption.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                client.mv("hdfs:/test_hdfs_client", "hdfs:/test_hdfs_client2")
        """
        if overwrite and self.is_exist(fs_dst_path):
            self.delete(fs_dst_path)

        if test_exists:
            if not self.is_exist(fs_src_path):
                raise FSFileNotExistsError(
                    "{} is not exists".format(fs_src_path))

            if self.is_exist(fs_dst_path):
                raise FSFileExistsError("{} exists already".format(fs_dst_path))

        return self._try_mv(fs_src_path, fs_dst_path)

    @_handle_errors()
    def _try_mv(self, fs_src_path, fs_dst_path):
        cmd = "mv {} {}".format(fs_src_path, fs_dst_path)
        ret = 0
        try:
            ret, _ = self._run_cmd(cmd, retry_times=1)
            if ret != 0:
                raise ExecuteError(cmd)
        except Exception as e:
            if not self.is_exist(fs_src_path) and \
                    self.is_exist(fs_dst_path):
                return
            raise e

    def _rmr(self, fs_path):
        cmd = "rmr {}".format(fs_path)
        ret, _ = self._run_cmd(cmd)
        if ret != 0:
            raise ExecuteError(cmd)

    def _rm(self, fs_path):
        cmd = "rm {}".format(fs_path)
        ret, _ = self._run_cmd(cmd)
        if ret != 0:
            raise ExecuteError(cmd)

    @_handle_errors()
    def delete(self, fs_path):
        """
        Delete a remote HDFS path, whether it's a file or directory.

        Args:
            fs_path(str): The HDFS file path.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                client.delete("hdfs:/test_hdfs_client")
        """
        if not self.is_exist(fs_path):
            return

        is_dir = self._is_dir(fs_path)
        if is_dir:
            return self._rmr(fs_path)

        return self._rm(fs_path)

    def touch(self, fs_path, exist_ok=True):
        """
        Create a remote HDFS file.

        Args:
            fs_path(str): The HDFS file path.
            exist_ok(bool): When `fs_path` exists, if `exist_ok` is set false,
            program will throw an Exception. Default is true.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                client.touch("hdfs:/test_hdfs_client")
        """
        if self.is_exist(fs_path):
            if exist_ok:
                return
            raise FSFileExistsError

        return self._touchz(fs_path)

    @_handle_errors()
    def _touchz(self, fs_path):
        cmd = "touchz {}".format(fs_path)
        ret, _ = self._run_cmd(cmd)
        if ret != 0:
            raise ExecuteError(cmd)

    def need_upload_download(self):
        return True

    def cat(self, fs_path=None):
        """
        Cat a remote HDFS file.

        Args:
            fs_path(str): The HDFS file path.

        Returns:
            file content

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                hadoop_home = "/home/client/hadoop-client/hadoop/"
                configs = {
                    "fs.default.name": "hdfs://xxx.hadoop.com:54310",
                    "hadoop.job.ugi": "hello,hello123"
                }

                client = HDFSClient(hadoop_home, configs)
                client.cat("hdfs:/test_hdfs_client")
        """
        if self.is_file(fs_path):
            output = self._try_cat(fs_path)
            return "\n".join(output)
        else:
            return ""

    @_handle_errors()
    def _try_cat(self, fs_path):
        cmd = "cat {}".format(fs_path)
        ret, output = self._run_cmd(cmd, retry_times=1)
        if ret != 0:
            raise ExecuteError(cmd)
        return output

    def _split_files(self, files, trainer_id, trainers):
        """
        split file list
        Args:
            files(list): file list
            trainer_id(int): trainer mpi rank id
            trainers(int): all trainers num
        Returns:
            fileist(list): file list of current trainer
        """
        remainder = len(files) % trainers
        blocksize = len(files) // trainers

        blocks = [blocksize] * trainers
        for i in range(remainder):
            blocks[i] += 1

        trainer_files = [[]] * trainers
        begin = 0
        for i in range(trainers):
            trainer_files[i] = files[begin:begin + blocks[i]]
            begin += blocks[i]

        return trainer_files[trainer_id]

    def list_files_info(self, path_list):
        """
        list_files return file path and size
        Args:
            path_list(list): file list
        Returns:
            fileist(list): file list with file path and size
        """
        if len(path_list) <= 0:
            return []

        file_list = []

        #concat filelist can speed up 'hadoop ls'
        str_concat = ""
        for path in path_list:
            str_concat += path + " "
        cmd = "ls " + str_concat + " | awk '{if ($8 != \"\") {print $5\" \"$8 }}'"
        ret, lines = self._run_cmd(cmd)
        if (len(lines) == 0):
            logger.warning("list_files empty, path[%s]" % path_list)
            return []
        for line in lines:
            arr = line.split(' ')
            if len(arr) < 2:
                continue
            file_path = arr[1]
            file_size = int(arr[0])
            file_list.append({'path': file_path, 'size': file_size})

        return file_list


class AFSClient(FS):
    """
    A tool of AFS. Use AfsWrapper.

    Examples:

        .. code-block:: text

            from paddle.distributed.fleet.utils import AFSClient
            client = AFSClient()
            client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
            client.ls_dir("hdfs:/test_hdfs_client")
    """

    def __init__(
            self,
            time_out=5 * 60 * 1000,  # ms
            sleep_inter=1000):  # ms
        self._fs = core.AfsWrapper()
        self._time_out = time_out

    def init(self, fs_name, fs_user, fs_passwd, fs_conf):
        self._fs.init(fs_name, fs_user, fs_passwd, fs_conf)

    def list_dirs(self, fs_path):
        """
        Only list directorys under `fs_path` .

        Args:
            fs_path(str): The HDFS file path.

        Returns:
            List: A list of all its subdirectories, e.g. [subdirname1, subdirname1, ...].

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                subdirs = client.list_dirs("hdfs:/test_hdfs_client")
        """
        if not self.is_exist(fs_path):
            return []
        # TODO:fengdanlei
        dirs, files = self._ls_dir(fs_path)
        return dirs

    def ls_dir(self, fs_path):
        """
        List directorys and files under `fs_path` .

        Args:
            fs_path(str): The HDFS file path.

        Returns:
            Tuple: Return a 2-tuple, the first element is the list of all its subdirectories,
            and the second one is the list of all its subfiles, e.g. ([subdirname1, subdirname1, ...], [filename1, filename2, ...]).

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                subdirs, files = client.ls_dir("hdfs:/test_hdfs_client")
        """
        if not self.is_exist(fs_path):
            return [], []

        return self._ls_dir(fs_path)

    def _ls_dir(self, fs_path):

        files = self._fs.list(fs_path)
        dirs = [fs_path]
        return dirs, files

    def is_dir(self, fs_path):
        """
        Whether the remote HDFS path is a directory.

        Args:
            fs_path(str): The HDFS file path.

        Returns:
            Bool: Return true if the path exists and it's a directory, otherwise return false.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                ret = client.is_file("hdfs:/test_hdfs_client")
        """
        if not self.is_exist(fs_path):
            return False

        return self._is_dir(fs_path)

    def _is_dir(self, fs_path):
        list_path = self._fs.list(fs_path)
        if (len(list_path)) > 0:
            return True
        else:
            return False

    def is_file(self, fs_path):
        """
        Whether the remote HDFS path is a file.

        Args:
            fs_path(str): The HDFS file path.

        Returns:
            Bool: Return true if the path exists and it's a file, otherwise return false.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                ret = client.is_file("hdfs:/test_hdfs_client")
        """
        if not self.is_exist(fs_path):
            return False

        return not self._is_dir(fs_path)

    def is_exist(self, fs_path):
        """
        Whether the remote HDFS path exists.

        Args:
            fs_path(str): The hdfs file path.

        Returns:
            Bool: Whether it's is file or directory, return true if the path exists,
            otherwise return false.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                ret = client.is_exist("hdfs:/test_hdfs_client")
        """
        return self._fs.exist(fs_path)

    def upload_dir(self, local_dir, dest_dir, overwrite=False):
        """
        upload dir to hdfs
        Args:
            local_dir(str): local dir
            dest_dir(str): hdfs dest dir
            overwrite(bool): is overwrite
        Returns:
            return code
        """
        local_dir = local_dir.rstrip("/")
        dest_dir = dest_dir.rstrip("/")
        local_basename = os.path.basename(local_dir)
        if self.is_exist(dest_dir + "/" + local_basename) and overwrite:
            self.delete(dest_dir + "/" + local_basename)
        if not self.is_exist(dest_dir):
            self.mkdirs(dest_dir)
        self._fs.upload(local_dir, dest_dir)

    # can't retry
    def upload(self, local_path, fs_path, multi_processes=1, overwrite=False):
        """
        Upload the local path to remote HDFS.

        Args:
            local_path(str): The local path.
            fs_path(str): The HDFS path.
            multi_processes(int|1): the upload data process at the same time, default=5
            overwrite(bool|False): will overwrite file on HDFS or not

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                client.upload("test_hdfs_client", "hdfs:/test_hdfs_client")
        """

        local = LocalFS()
        if not local.is_exist(local_path):
            raise FSFileNotExistsError("{} not exists".format(local_path))

        self._fs.upload(local_path, fs_path)

    def download(self, fs_path, local_path, multi_processes=1, overwrite=False):
        """
        Download remote HDFS path to the local.

        Args:
            fs_path(str):  The HDFS path.
            local_path(str): The local path.
            multi_processes(int|1): the download data process at the same time, default=1
            overwrite(bool): is overwrite

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                client.download("hdfs:/test_hdfs_client", "./")
        """

        def __subprocess_download(local_path, datas):
            """
            download file from HDFS
            Args:
                local_path(str): the local file path
                datas(str): the hdfs file path list
            """
            for data in datas:
                self._fs.download(local_path, data)

        if not self.is_exist(fs_path):
            raise FSFileNotExistsError("{} not exits".format(fs_path))
        # download file
        if self.is_file(fs_path):
            return self._fs.download(local_path, fs_path)
        # download dir
        _, all_filenames = self.ls_dir(fs_path)
        all_files = [fs_path + i for i in all_filenames]
        procs = []
        for i in range(multi_processes):
            process_datas = self._split_files(all_files, i, multi_processes)
            p = multiprocessing.Process(target=__subprocess_download,
                                        args=(local_path, process_datas))
            procs.append(p)
            p.start()

        # complete the processes
        for proc in procs:
            proc.join()

    def mkdirs(self, fs_path):
        """
        Create a remote HDFS directory.

        Args:
            fs_path(str): The HDFS directory path.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                client.mkdirs("hdfs:/test_hdfs_client")
        """
        if self.is_exist(fs_path):
            return
        self._fs.mkdir(fs_path)

    def mv(self, fs_src_path, fs_dst_path, overwrite=False, test_exists=True):
        """
        Move a remote HDFS file or directory from `fs_src_path` to `fs_dst_path` .

        Args:
            fs_src_path(str):  Name of the file or directory, that's needed to be moved.
            fs_dst_path(str):  Name of the file or directory to which to move to.
            overwrite(bool): Whether to re-write `fs_dst_path` if that exists. Default is False.
            test_exists(bool): Check the existence of `fs_src_path` and `fs_dst_path` . When `test_exists` is set true, if `fs_src_path` doesn't exist or `fs_dst_path` exists, program will throw an Excetption.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                client.mv("hdfs:/test_hdfs_client", "hdfs:/test_hdfs_client2")
        """
        if overwrite and self.is_exist(fs_dst_path):
            self.delete(fs_dst_path)

        if test_exists:
            if not self.is_exist(fs_src_path):
                raise FSFileNotExistsError(
                    "{} is not exists".format(fs_src_path))

            if self.is_exist(fs_dst_path):
                raise FSFileExistsError("{} exists already".format(fs_dst_path))

        self._fs.mv(fs_src_path, fs_dst_path)

    def delete(self, fs_path):
        """
        Delete a remote HDFS path, whether it's a file or directory.

        Args:
            fs_path(str): The HDFS file path.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import HDFSClient

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                client.delete("hdfs:/test_hdfs_client")
        """
        if not self.is_exist(fs_path):
            return
        self._fs.remove(fs_path)

    def touch(self, fs_path, exist_ok=True):
        """
        Create a remote HDFS file.

        Args:
            fs_path(str): The HDFS file path.
            exist_ok(bool): When `fs_path` exists, if `exist_ok` is set false,
            program will throw an Exception. Default is true.

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                client.touch("hdfs:/test_hdfs_client")
        """
        if self.is_exist(fs_path):
            if exist_ok:
                return
            raise FSFileExistsError

        return self._fs.touchz(fs_path)

    def need_upload_download(self):
        return True

    def cat(self, fs_path=None):
        """
        Cat a remote HDFS file.

        Args:
            fs_path(str): The HDFS file path.

        Returns:
            file content

        Examples:

            .. code-block:: text

                from paddle.distributed.fleet.utils import AFSClient

                client = AFSClient()
                client.init("hdfs://xxx.hadoop.com:54310", "hello", "hello123", "./fs_conf")
                client.cat("hdfs:/test_hdfs_client")
        """
        if self.is_file(fs_path):
            return self._fs.cat(fs_path)
        else:
            return ""

    def _split_files(self, files, trainer_id, trainers):
        """
        split file list
        Args:
            files(list): file list
            trainer_id(int): trainer mpi rank id
            trainers(int): all trainers num
        Returns:
            fileist(list): file list of current trainer
        """
        remainder = len(files) % trainers
        blocksize = len(files) // trainers

        blocks = [blocksize] * trainers
        for i in range(remainder):
            blocks[i] += 1

        trainer_files = [[]] * trainers
        begin = 0
        for i in range(trainers):
            trainer_files[i] = files[begin:begin + blocks[i]]
            begin += blocks[i]

        return trainer_files[trainer_id]