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# Copyright (C) 2010 Google Inc.

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# This program is free software; you can redistribute it and/or modify

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# General Public License for more details.

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

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"""User-id pool related functions.

The user-id pool is cluster-wide configuration option.

It is stored as a list of user-id ranges.

This module contains functions used for manipulating the

user-id pool parameter and for requesting/returning user-ids

from the pool.

"""

from ganeti import errors

from ganeti import constants

def ParseUidPool(value, separator=None):

  """Parse a user-id pool definition.

  @param value: string representation of the user-id pool.

                The accepted input format is a list of integer ranges.

                The boundaries are inclusive.

                Example: '1000-5000,8000,9000-9010'.

  @param separator: the separator character between the uids/uid-ranges.

                    Defaults to a comma.

  @return: a list of integer pairs (lower, higher range boundaries)

  """

  if separator is None:

    separator = ","

  ranges = []

  for range_def in value.split(separator):

    if not range_def:

      # Skip empty strings

      continue

    boundaries = range_def.split("-")

    n_elements = len(boundaries)

    if n_elements > 2:

      raise errors.OpPrereqError(

          "Invalid user-id range definition. Only one hyphen allowed: %s"

          % boundaries)

    try:

      lower = int(boundaries[0])

    except (ValueError, TypeError), err:

      raise errors.OpPrereqError("Invalid user-id value for lower boundary of"

                                 " user-id range: %s"

                                 % str(err), errors.ECODE_INVAL)

    try:

      higher = int(boundaries[n_elements - 1])

    except (ValueError, TypeError), err:

      raise errors.OpPrereqError("Invalid user-id value for higher boundary of"

                                 " user-id range: %s"

                                 % str(err), errors.ECODE_INVAL)

    ranges.append((lower, higher))

  ranges.sort()

  return ranges

def CheckUidPool(uid_pool):

  """Sanity check user-id pool range definition values.

  @param uid_pool: a list of integer pairs (lower, higher range boundaries)

  """

  for lower, higher in uid_pool:

    if lower > higher:

      raise errors.OpPrereqError(

          "Lower user-id range boundary value (%s)"

          " is larger than higher boundary value (%s)" %

          (lower, higher), errors.ECODE_INVAL)

    if lower < constants.UIDPOOL_UID_MIN:

      raise errors.OpPrereqError(

          "Lower user-id range boundary value (%s)"

          " is smaller than UIDPOOL_UID_MIN (%s)." %

          (lower, constants.UIDPOOL_UID_MIN),

          errors.ECODE_INVAL)

    if higher > constants.UIDPOOL_UID_MAX:

      raise errors.OpPrereqError(

          "Higher user-id boundary value (%s)"

          " is larger than UIDPOOL_UID_MAX (%s)." %

          (higher, constants.UIDPOOL_UID_MAX),

          errors.ECODE_INVAL)

def ExpandUidPool(uid_pool):

  """Expands a uid-pool definition to a list of uids.

  @param uid_pool: a list of integer pairs (lower, higher range boundaries)

  @return: a list of integers

  """

  uids = set()

  for lower, higher in uid_pool:

    uids.update(range(lower, higher + 1))

  return list(uids)