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# Copyright (c) Microsoft Corporation
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# MIT License
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import argparse
import sys
import os
from subprocess import Popen, PIPE
import time
import logging
import shlex
import re
from pyhdfs import HdfsClient

from .hdfsClientUtility import copyDirectoryToHdfs
from .constants import HOME_DIR, LOG_DIR, STDOUT_FULL_PATH, STDERR_FULL_PATH
from .metrics_reader import read_experiment_metrics

logger = logging.getLogger('trial_keeper')

def main_loop(args):
    '''main loop logic for trial keeper'''
    
    if not os.path.exists(LOG_DIR):
        os.makedirs(LOG_DIR)
    
    stdout_file = open(STDOUT_FULL_PATH, 'a+')
    stderr_file = open(STDERR_FULL_PATH, 'a+')
    print(shlex.split(args.trial_command))
    # Notice: We don't appoint env, which means subprocess wil inherit current environment and that is expected behavior
    process = Popen(args.trial_command, shell = True, stdout = stdout_file, stderr = stderr_file)
    print('Subprocess pid is {}'.format(process.pid))
    while True:
        retCode = process.poll()
        ## Read experiment metrics, to avoid missing metrics
        read_experiment_metrics(args.nnimanager_ip)
        
        if retCode is not None:
            print('subprocess terminated. Exit code is {}. Quit'.format(retCode))
            #copy local directory to hdfs
            nni_local_output_dir = os.environ['NNI_OUTPUT_DIR']
            try:
                hdfs_client = HdfsClient(hosts='{0}:{1}'.format(args.pai_hdfs_host, '50070'), user_name=args.pai_user_name, timeout=5)
                if copyDirectoryToHdfs(nni_local_output_dir, args.pai_hdfs_output_dir, hdfs_client):
                    print('copy directory from {0} to {1} success!'.format(nni_local_output_dir, args.pai_hdfs_output_dir))
                else:
                    print('copy directory from {0} to {1} failed!'.format(nni_local_output_dir, args.pai_hdfs_output_dir))
            except Exception as exception:
                print('HDFS copy directory got exception')
                raise exception

            ## Exit as the retCode of subprocess(trial)
            exit(retCode)
            break
        else:
            print('subprocess pid: {} is still alive'.format(process.pid))

        time.sleep(2)

def trial_keeper_help_info(*args):
    print('please run --help to see guidance')

if __name__ == '__main__':
    '''NNI Trial Keeper main function'''
    PARSER = argparse.ArgumentParser()
    PARSER.set_defaults(func=trial_keeper_help_info)
    PARSER.add_argument('--trial_command', type=str, help='Command to launch trial process')
    PARSER.add_argument('--nnimanager_ip', type=str, default='localhost', help='NNI manager IP')
    PARSER.add_argument('--pai_hdfs_output_dir', type=str, help='the output dir of hdfs')
    PARSER.add_argument('--pai_hdfs_host', type=str, help='the host of hdfs')
    PARSER.add_argument('--pai_user_name', type=str, help='the username of hdfs')
    args, unknown = PARSER.parse_known_args()
    if args.trial_command is None:
        exit(1)

    try:
        main_loop(args)
    except SystemExit as se:
        print('NNI trial keeper exit with code {}'.format(se.code))
        sys.exit(se.code)
    except Exception as e:
        print('Exit trial keeper with code 1 because Exception: {} is catched'.format(str(e)))
        sys.exit(1)

