FileWaiter.py

Go to the documentation of this file.

#!/usr/bin/env python

#
# LSST Data Management System
# Copyright 2008, 2009, 2010 LSST Corporation.
#
# This product includes software developed by the
# LSST Project (http://www.lsst.org/).
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the LSST License Statement and
# the GNU General Public License along with this program.  If not,
# see <http://www.lsstcorp.org/LegalNotices/>.
#


from __future__ import print_function
from builtins import object
import os
import lsst.log as log


class FileWaiter(object):
    # @brief initializer
    """Waits for files to come into existence on a remote resource
    Parameters
    ----------
    remoteNode : `str`
        Name of the remote node to execute on
    remoteFileWaiter : `str`
        name of the remote file waiter script
    fileListName : `str`
        name of the remote file list file
    logger: `Log`, optional
        lsst.log logging object

    Notes
    -----
    Use of logger in this way should be deprecated in the future
    """
    def __init__(self, remoteNode, remoteFileWaiter, fileListName, logger=None):
        log.debug("FileWaiter:__init__")

        self.remoteNode = remoteNode

        self.fileListName = fileListName

        self.remoteFileWaiter = remoteFileWaiter

    def waitForFirstFile(self):
        """Waits for first file in the list to come into existence
        """
        log.debug("FileWaiter:waitForFirstFile")
        print("waiting for log file to be created to confirm launch.")
        cmd = "gsissh %s %s -f %s" % (self.remoteNode, self.remoteFileWaiter, self.fileListName)
        pid = os.fork()
        if not pid:
            os.execvp("gsissh", cmd.split())
        os.wait()[0]

    def waitForAllFiles(self):
        """Waits for all files in the list to come into existence
        """
        log.debug("FileWaiter:waitForAllFiles")

        print("waiting for all log files to be created to confirm launch")
        cmd = "gsissh %s %s -l %s" % (self.remoteNode, self.remoteFileWaiter, self.fileListName)
        pid = os.fork()
        if not pid:
            os.execvp("gsissh", cmd.split())
        os.wait()[0]