Synnefo » snf-ganeti » ganeti-local

#

#

# Copyright (C) 2006, 2007 Google Inc.

#

# 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 2 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.

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# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

# 02110-1301, USA.

"""Module implementing the job queue handling."""

import threading

import Queue

from ganeti import opcodes

from ganeti import errors

class JobObject:

  """In-memory job representation.

  This is what we use to track the user-submitted jobs (which are of

  class opcodes.Job).

  """

  def __init__(self, jid, jdesc):

    self.data = jdesc

    jdesc.status = opcodes.Job.STATUS_PENDING

    jdesc.job_id = jid

    jdesc.op_status = [opcodes.Job.STATUS_PENDING for i in jdesc.op_list]

    jdesc.op_result = [None for i in jdesc.op_list]

    self.lock = threading.Lock()

  def SetStatus(self, status, result=None):

    self.lock.acquire()

    self.data.status = status

    if result is not None:

      self.data.result = result

    self.lock.release()

  def GetData(self):

    self.lock.acquire()

    #FIXME(iustin): make a deep copy of result

    result = self.data

    self.lock.release()

    return result

class QueueManager:

  """Example queue implementation.

  """

  def __init__(self):

    self.job_queue = {}

    self.jid = 1

    self.lock = threading.Lock()

    self.new_queue = Queue.Queue()

  def put(self, item):

    """Add a new job to the queue.

    This enters the job into our job queue and also puts it on the new

    queue, in order for it to be picked up by the queue processors.

    """

    self.lock.acquire()

    try:

      rid = self.jid

      self.jid += 1

      job = JobObject(rid, item)

      self.job_queue[rid] = job

    finally:

      self.lock.release()

    self.new_queue.put(job)

    return rid

  def query(self, rid):

    """Query a given job ID.

    """

    self.lock.acquire()

    result = self.job_queue.get(rid, None)

    self.lock.release()

    return result

  def query_jobs(self, fields, names):

    """Query all jobs.

    The fields and names parameters are similar to the ones passed to

    the OpQueryInstances.

    """

    result = []

    self.lock.acquire()

    if names:

      values = [self.job_queue[j_id] for j_id in names]

    else:

      values = self.job_queue.itervalues()

    try:

      for jobj in values:

        row = []

        jdata = jobj.data

        for fname in fields:

          if fname == "id":

            row.append(jdata.job_id)

          elif fname == "status":

            row.append(jdata.status)

          elif fname == "op_list":

            row.append([op.__getstate__() for op in jdata.op_list])

          elif fname == "op_status":

            row.append(jdata.op_status)

          elif fname == "op_result":

            row.append(jdata.op_result)

          else:

            raise errors.OpExecError("Invalid job query field '%s'" %

                                           fname)

        result.append(row)

    finally:

      self.lock.release()

    return result