root / lib / utils / __init__.py @ 6b27f535
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#
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#
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# Copyright (C) 2006, 2007, 2010, 2011 Google Inc.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301, USA.
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"""Ganeti utility module.
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This module holds functions that can be used in both daemons (all) and
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the command line scripts.
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"""
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# Allow wildcard import in pylint: disable=W0401
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import os |
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import re |
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import errno |
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import pwd |
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import time |
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import itertools |
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import select |
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import logging |
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import signal |
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from ganeti import errors |
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from ganeti import constants |
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from ganeti import compat |
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from ganeti.utils.algo import * |
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from ganeti.utils.filelock import * |
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from ganeti.utils.hash import * |
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from ganeti.utils.io import * |
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from ganeti.utils.log import * |
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from ganeti.utils.mlock import * |
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from ganeti.utils.nodesetup import * |
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from ganeti.utils.process import * |
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from ganeti.utils.retry import * |
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from ganeti.utils.text import * |
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from ganeti.utils.wrapper import * |
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from ganeti.utils.x509 import * |
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_VALID_SERVICE_NAME_RE = re.compile("^[-_.a-zA-Z0-9]{1,128}$")
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UUID_RE = re.compile("^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-"
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"[a-f0-9]{4}-[a-f0-9]{12}$")
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def ForceDictType(target, key_types, allowed_values=None): |
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"""Force the values of a dict to have certain types.
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@type target: dict
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@param target: the dict to update
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@type key_types: dict
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@param key_types: dict mapping target dict keys to types
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in constants.ENFORCEABLE_TYPES
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@type allowed_values: list
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@keyword allowed_values: list of specially allowed values
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"""
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if allowed_values is None: |
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allowed_values = [] |
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if not isinstance(target, dict): |
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msg = "Expected dictionary, got '%s'" % target
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raise errors.TypeEnforcementError(msg)
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for key in target: |
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if key not in key_types: |
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msg = "Unknown parameter '%s'" % key
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raise errors.TypeEnforcementError(msg)
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if target[key] in allowed_values: |
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continue
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ktype = key_types[key] |
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if ktype not in constants.ENFORCEABLE_TYPES: |
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msg = "'%s' has non-enforceable type %s" % (key, ktype)
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raise errors.ProgrammerError(msg)
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if ktype in (constants.VTYPE_STRING, constants.VTYPE_MAYBE_STRING): |
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if target[key] is None and ktype == constants.VTYPE_MAYBE_STRING: |
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pass
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elif not isinstance(target[key], basestring): |
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if isinstance(target[key], bool) and not target[key]: |
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target[key] = ""
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else:
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msg = "'%s' (value %s) is not a valid string" % (key, target[key])
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raise errors.TypeEnforcementError(msg)
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elif ktype == constants.VTYPE_BOOL:
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if isinstance(target[key], basestring) and target[key]: |
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if target[key].lower() == constants.VALUE_FALSE:
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target[key] = False
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elif target[key].lower() == constants.VALUE_TRUE:
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target[key] = True
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else:
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msg = "'%s' (value %s) is not a valid boolean" % (key, target[key])
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raise errors.TypeEnforcementError(msg)
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elif target[key]:
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target[key] = True
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else:
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target[key] = False
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elif ktype == constants.VTYPE_SIZE:
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try:
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target[key] = ParseUnit(target[key]) |
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except errors.UnitParseError, err:
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msg = "'%s' (value %s) is not a valid size. error: %s" % \
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(key, target[key], err) |
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raise errors.TypeEnforcementError(msg)
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elif ktype == constants.VTYPE_INT:
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try:
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target[key] = int(target[key])
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except (ValueError, TypeError): |
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msg = "'%s' (value %s) is not a valid integer" % (key, target[key])
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raise errors.TypeEnforcementError(msg)
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def ValidateServiceName(name): |
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"""Validate the given service name.
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@type name: number or string
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@param name: Service name or port specification
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"""
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try:
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numport = int(name)
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except (ValueError, TypeError): |
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# Non-numeric service name
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valid = _VALID_SERVICE_NAME_RE.match(name) |
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else:
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# Numeric port (protocols other than TCP or UDP might need adjustments
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# here)
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valid = (numport >= 0 and numport < (1 << 16)) |
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if not valid: |
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raise errors.OpPrereqError("Invalid service name '%s'" % name, |
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errors.ECODE_INVAL) |
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return name
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def ListVolumeGroups(): |
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"""List volume groups and their size
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@rtype: dict
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@return:
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Dictionary with keys volume name and values
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the size of the volume
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"""
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command = "vgs --noheadings --units m --nosuffix -o name,size"
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result = RunCmd(command) |
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retval = {} |
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if result.failed:
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return retval
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for line in result.stdout.splitlines(): |
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try:
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name, size = line.split() |
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size = int(float(size)) |
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except (IndexError, ValueError), err: |
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logging.error("Invalid output from vgs (%s): %s", err, line)
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continue
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retval[name] = size |
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return retval
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def BridgeExists(bridge): |
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"""Check whether the given bridge exists in the system
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@type bridge: str
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@param bridge: the bridge name to check
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@rtype: boolean
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@return: True if it does
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"""
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return os.path.isdir("/sys/class/net/%s/bridge" % bridge) |
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def TryConvert(fn, val): |
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"""Try to convert a value ignoring errors.
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This function tries to apply function I{fn} to I{val}. If no
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C{ValueError} or C{TypeError} exceptions are raised, it will return
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the result, else it will return the original value. Any other
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exceptions are propagated to the caller.
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@type fn: callable
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@param fn: function to apply to the value
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@param val: the value to be converted
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@return: The converted value if the conversion was successful,
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otherwise the original value.
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"""
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try:
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nv = fn(val) |
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except (ValueError, TypeError): |
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nv = val |
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return nv
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def ParseCpuMask(cpu_mask): |
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"""Parse a CPU mask definition and return the list of CPU IDs.
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CPU mask format: comma-separated list of CPU IDs
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or dash-separated ID ranges
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Example: "0-2,5" -> "0,1,2,5"
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@type cpu_mask: str
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@param cpu_mask: CPU mask definition
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@rtype: list of int
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@return: list of CPU IDs
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"""
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if not cpu_mask: |
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return []
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cpu_list = [] |
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for range_def in cpu_mask.split(","): |
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boundaries = range_def.split("-")
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n_elements = len(boundaries)
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if n_elements > 2: |
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raise errors.ParseError("Invalid CPU ID range definition" |
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" (only one hyphen allowed): %s" % range_def)
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try:
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lower = int(boundaries[0]) |
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except (ValueError, TypeError), err: |
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raise errors.ParseError("Invalid CPU ID value for lower boundary of" |
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" CPU ID range: %s" % str(err)) |
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try:
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higher = int(boundaries[-1]) |
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except (ValueError, TypeError), err: |
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raise errors.ParseError("Invalid CPU ID value for higher boundary of" |
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" CPU ID range: %s" % str(err)) |
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if lower > higher:
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raise errors.ParseError("Invalid CPU ID range definition" |
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" (%d > %d): %s" % (lower, higher, range_def))
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cpu_list.extend(range(lower, higher + 1)) |
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return cpu_list
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def GetHomeDir(user, default=None): |
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"""Try to get the homedir of the given user.
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The user can be passed either as a string (denoting the name) or as
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an integer (denoting the user id). If the user is not found, the
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'default' argument is returned, which defaults to None.
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"""
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try:
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if isinstance(user, basestring): |
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result = pwd.getpwnam(user) |
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elif isinstance(user, (int, long)): |
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result = pwd.getpwuid(user) |
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else:
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raise errors.ProgrammerError("Invalid type passed to GetHomeDir (%s)" % |
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type(user))
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except KeyError: |
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return default
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return result.pw_dir
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def FirstFree(seq, base=0): |
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"""Returns the first non-existing integer from seq.
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The seq argument should be a sorted list of positive integers. The
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first time the index of an element is smaller than the element
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value, the index will be returned.
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The base argument is used to start at a different offset,
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i.e. C{[3, 4, 6]} with I{offset=3} will return 5.
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Example: C{[0, 1, 3]} will return I{2}.
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@type seq: sequence
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@param seq: the sequence to be analyzed.
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@type base: int
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@param base: use this value as the base index of the sequence
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@rtype: int
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@return: the first non-used index in the sequence
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"""
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for idx, elem in enumerate(seq): |
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assert elem >= base, "Passed element is higher than base offset" |
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if elem > idx + base:
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# idx is not used
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return idx + base
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return None |
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def SingleWaitForFdCondition(fdobj, event, timeout): |
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"""Waits for a condition to occur on the socket.
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Immediately returns at the first interruption.
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@type fdobj: integer or object supporting a fileno() method
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@param fdobj: entity to wait for events on
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@type event: integer
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@param event: ORed condition (see select module)
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@type timeout: float or None
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@param timeout: Timeout in seconds
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@rtype: int or None
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@return: None for timeout, otherwise occured conditions
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"""
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check = (event | select.POLLPRI | |
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select.POLLNVAL | select.POLLHUP | select.POLLERR) |
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if timeout is not None: |
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# Poller object expects milliseconds
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timeout *= 1000
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poller = select.poll() |
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poller.register(fdobj, event) |
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try:
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# TODO: If the main thread receives a signal and we have no timeout, we
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# could wait forever. This should check a global "quit" flag or something
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# every so often.
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io_events = poller.poll(timeout) |
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except select.error, err:
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if err[0] != errno.EINTR: |
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raise
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io_events = [] |
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if io_events and io_events[0][1] & check: |
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return io_events[0][1] |
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else:
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return None |
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class FdConditionWaiterHelper(object): |
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"""Retry helper for WaitForFdCondition.
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This class contains the retried and wait functions that make sure
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WaitForFdCondition can continue waiting until the timeout is actually
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expired.
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"""
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def __init__(self, timeout): |
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self.timeout = timeout
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def Poll(self, fdobj, event): |
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result = SingleWaitForFdCondition(fdobj, event, self.timeout)
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if result is None: |
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raise RetryAgain()
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else:
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return result
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def UpdateTimeout(self, timeout): |
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self.timeout = timeout
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def WaitForFdCondition(fdobj, event, timeout): |
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"""Waits for a condition to occur on the socket.
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Retries until the timeout is expired, even if interrupted.
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@type fdobj: integer or object supporting a fileno() method
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@param fdobj: entity to wait for events on
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@type event: integer
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@param event: ORed condition (see select module)
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@type timeout: float or None
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@param timeout: Timeout in seconds
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@rtype: int or None
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@return: None for timeout, otherwise occured conditions
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"""
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if timeout is not None: |
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retrywaiter = FdConditionWaiterHelper(timeout) |
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try:
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result = Retry(retrywaiter.Poll, RETRY_REMAINING_TIME, timeout, |
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args=(fdobj, event), wait_fn=retrywaiter.UpdateTimeout) |
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except RetryTimeout:
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result = None
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else:
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result = None
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while result is None: |
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result = SingleWaitForFdCondition(fdobj, event, timeout) |
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return result
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def EnsureDaemon(name): |
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"""Check for and start daemon if not alive.
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"""
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result = RunCmd([constants.DAEMON_UTIL, "check-and-start", name])
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if result.failed:
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logging.error("Can't start daemon '%s', failure %s, output: %s",
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name, result.fail_reason, result.output) |
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return False |
408 |
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return True |
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def StopDaemon(name): |
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"""Stop daemon
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"""
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result = RunCmd([constants.DAEMON_UTIL, "stop", name])
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if result.failed:
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logging.error("Can't stop daemon '%s', failure %s, output: %s",
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name, result.fail_reason, result.output) |
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return False |
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return True |
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def CheckVolumeGroupSize(vglist, vgname, minsize): |
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"""Checks if the volume group list is valid.
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The function will check if a given volume group is in the list of
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volume groups and has a minimum size.
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@type vglist: dict
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@param vglist: dictionary of volume group names and their size
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@type vgname: str
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@param vgname: the volume group we should check
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@type minsize: int
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@param minsize: the minimum size we accept
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@rtype: None or str
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@return: None for success, otherwise the error message
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"""
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vgsize = vglist.get(vgname, None)
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if vgsize is None: |
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return "volume group '%s' missing" % vgname |
444 |
elif vgsize < minsize:
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return ("volume group '%s' too small (%s MiB required, %d MiB found)" % |
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(vgname, minsize, vgsize)) |
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return None |
448 |
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def SplitTime(value): |
451 |
"""Splits time as floating point number into a tuple.
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@param value: Time in seconds
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@type value: int or float
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@return: Tuple containing (seconds, microseconds)
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"""
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(seconds, microseconds) = divmod(int(value * 1000000), 1000000) |
459 |
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assert 0 <= seconds, \ |
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"Seconds must be larger than or equal to 0, but are %s" % seconds
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assert 0 <= microseconds <= 999999, \ |
463 |
"Microseconds must be 0-999999, but are %s" % microseconds
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return (int(seconds), int(microseconds)) |
466 |
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|
468 |
def MergeTime(timetuple): |
469 |
"""Merges a tuple into time as a floating point number.
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470 |
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471 |
@param timetuple: Time as tuple, (seconds, microseconds)
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@type timetuple: tuple
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473 |
@return: Time as a floating point number expressed in seconds
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474 |
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"""
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(seconds, microseconds) = timetuple |
477 |
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assert 0 <= seconds, \ |
479 |
"Seconds must be larger than or equal to 0, but are %s" % seconds
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assert 0 <= microseconds <= 999999, \ |
481 |
"Microseconds must be 0-999999, but are %s" % microseconds
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return float(seconds) + (float(microseconds) * 0.000001) |
484 |
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def FindMatch(data, name): |
487 |
"""Tries to find an item in a dictionary matching a name.
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488 |
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489 |
Callers have to ensure the data names aren't contradictory (e.g. a regexp
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that matches a string). If the name isn't a direct key, all regular
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expression objects in the dictionary are matched against it.
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@type data: dict
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@param data: Dictionary containing data
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@type name: string
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@param name: Name to look for
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@rtype: tuple; (value in dictionary, matched groups as list)
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"""
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if name in data: |
501 |
return (data[name], [])
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for key, value in data.items(): |
504 |
# Regex objects
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505 |
if hasattr(key, "match"): |
506 |
m = key.match(name) |
507 |
if m:
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return (value, list(m.groups())) |
509 |
|
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return None |
511 |
|
512 |
|
513 |
def GetMounts(filename=constants.PROC_MOUNTS): |
514 |
"""Returns the list of mounted filesystems.
|
515 |
|
516 |
This function is Linux-specific.
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517 |
|
518 |
@param filename: path of mounts file (/proc/mounts by default)
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@rtype: list of tuples
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@return: list of mount entries (device, mountpoint, fstype, options)
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|
522 |
"""
|
523 |
# TODO(iustin): investigate non-Linux options (e.g. via mount output)
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data = [] |
525 |
mountlines = ReadFile(filename).splitlines() |
526 |
for line in mountlines: |
527 |
device, mountpoint, fstype, options, _ = line.split(None, 4) |
528 |
data.append((device, mountpoint, fstype, options)) |
529 |
|
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return data
|
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|
532 |
|
533 |
def SignalHandled(signums): |
534 |
"""Signal Handled decoration.
|
535 |
|
536 |
This special decorator installs a signal handler and then calls the target
|
537 |
function. The function must accept a 'signal_handlers' keyword argument,
|
538 |
which will contain a dict indexed by signal number, with SignalHandler
|
539 |
objects as values.
|
540 |
|
541 |
The decorator can be safely stacked with iself, to handle multiple signals
|
542 |
with different handlers.
|
543 |
|
544 |
@type signums: list
|
545 |
@param signums: signals to intercept
|
546 |
|
547 |
"""
|
548 |
def wrap(fn): |
549 |
def sig_function(*args, **kwargs): |
550 |
assert "signal_handlers" not in kwargs or \ |
551 |
kwargs["signal_handlers"] is None or \ |
552 |
isinstance(kwargs["signal_handlers"], dict), \ |
553 |
"Wrong signal_handlers parameter in original function call"
|
554 |
if "signal_handlers" in kwargs and kwargs["signal_handlers"] is not None: |
555 |
signal_handlers = kwargs["signal_handlers"]
|
556 |
else:
|
557 |
signal_handlers = {} |
558 |
kwargs["signal_handlers"] = signal_handlers
|
559 |
sighandler = SignalHandler(signums) |
560 |
try:
|
561 |
for sig in signums: |
562 |
signal_handlers[sig] = sighandler |
563 |
return fn(*args, **kwargs)
|
564 |
finally:
|
565 |
sighandler.Reset() |
566 |
return sig_function
|
567 |
return wrap
|
568 |
|
569 |
|
570 |
def TimeoutExpired(epoch, timeout, _time_fn=time.time): |
571 |
"""Checks whether a timeout has expired.
|
572 |
|
573 |
"""
|
574 |
return _time_fn() > (epoch + timeout)
|
575 |
|
576 |
|
577 |
class SignalWakeupFd(object): |
578 |
try:
|
579 |
# This is only supported in Python 2.5 and above (some distributions
|
580 |
# backported it to Python 2.4)
|
581 |
_set_wakeup_fd_fn = signal.set_wakeup_fd |
582 |
except AttributeError: |
583 |
# Not supported
|
584 |
def _SetWakeupFd(self, _): # pylint: disable=R0201 |
585 |
return -1 |
586 |
else:
|
587 |
def _SetWakeupFd(self, fd): |
588 |
return self._set_wakeup_fd_fn(fd) |
589 |
|
590 |
def __init__(self): |
591 |
"""Initializes this class.
|
592 |
|
593 |
"""
|
594 |
(read_fd, write_fd) = os.pipe() |
595 |
|
596 |
# Once these succeeded, the file descriptors will be closed automatically.
|
597 |
# Buffer size 0 is important, otherwise .read() with a specified length
|
598 |
# might buffer data and the file descriptors won't be marked readable.
|
599 |
self._read_fh = os.fdopen(read_fd, "r", 0) |
600 |
self._write_fh = os.fdopen(write_fd, "w", 0) |
601 |
|
602 |
self._previous = self._SetWakeupFd(self._write_fh.fileno()) |
603 |
|
604 |
# Utility functions
|
605 |
self.fileno = self._read_fh.fileno |
606 |
self.read = self._read_fh.read |
607 |
|
608 |
def Reset(self): |
609 |
"""Restores the previous wakeup file descriptor.
|
610 |
|
611 |
"""
|
612 |
if hasattr(self, "_previous") and self._previous is not None: |
613 |
self._SetWakeupFd(self._previous) |
614 |
self._previous = None |
615 |
|
616 |
def Notify(self): |
617 |
"""Notifies the wakeup file descriptor.
|
618 |
|
619 |
"""
|
620 |
self._write_fh.write("\0") |
621 |
|
622 |
def __del__(self): |
623 |
"""Called before object deletion.
|
624 |
|
625 |
"""
|
626 |
self.Reset()
|
627 |
|
628 |
|
629 |
class SignalHandler(object): |
630 |
"""Generic signal handler class.
|
631 |
|
632 |
It automatically restores the original handler when deconstructed or
|
633 |
when L{Reset} is called. You can either pass your own handler
|
634 |
function in or query the L{called} attribute to detect whether the
|
635 |
signal was sent.
|
636 |
|
637 |
@type signum: list
|
638 |
@ivar signum: the signals we handle
|
639 |
@type called: boolean
|
640 |
@ivar called: tracks whether any of the signals have been raised
|
641 |
|
642 |
"""
|
643 |
def __init__(self, signum, handler_fn=None, wakeup=None): |
644 |
"""Constructs a new SignalHandler instance.
|
645 |
|
646 |
@type signum: int or list of ints
|
647 |
@param signum: Single signal number or set of signal numbers
|
648 |
@type handler_fn: callable
|
649 |
@param handler_fn: Signal handling function
|
650 |
|
651 |
"""
|
652 |
assert handler_fn is None or callable(handler_fn) |
653 |
|
654 |
self.signum = set(signum) |
655 |
self.called = False |
656 |
|
657 |
self._handler_fn = handler_fn
|
658 |
self._wakeup = wakeup
|
659 |
|
660 |
self._previous = {}
|
661 |
try:
|
662 |
for signum in self.signum: |
663 |
# Setup handler
|
664 |
prev_handler = signal.signal(signum, self._HandleSignal)
|
665 |
try:
|
666 |
self._previous[signum] = prev_handler
|
667 |
except:
|
668 |
# Restore previous handler
|
669 |
signal.signal(signum, prev_handler) |
670 |
raise
|
671 |
except:
|
672 |
# Reset all handlers
|
673 |
self.Reset()
|
674 |
# Here we have a race condition: a handler may have already been called,
|
675 |
# but there's not much we can do about it at this point.
|
676 |
raise
|
677 |
|
678 |
def __del__(self): |
679 |
self.Reset()
|
680 |
|
681 |
def Reset(self): |
682 |
"""Restore previous handler.
|
683 |
|
684 |
This will reset all the signals to their previous handlers.
|
685 |
|
686 |
"""
|
687 |
for signum, prev_handler in self._previous.items(): |
688 |
signal.signal(signum, prev_handler) |
689 |
# If successful, remove from dict
|
690 |
del self._previous[signum] |
691 |
|
692 |
def Clear(self): |
693 |
"""Unsets the L{called} flag.
|
694 |
|
695 |
This function can be used in case a signal may arrive several times.
|
696 |
|
697 |
"""
|
698 |
self.called = False |
699 |
|
700 |
def _HandleSignal(self, signum, frame): |
701 |
"""Actual signal handling function.
|
702 |
|
703 |
"""
|
704 |
# This is not nice and not absolutely atomic, but it appears to be the only
|
705 |
# solution in Python -- there are no atomic types.
|
706 |
self.called = True |
707 |
|
708 |
if self._wakeup: |
709 |
# Notify whoever is interested in signals
|
710 |
self._wakeup.Notify()
|
711 |
|
712 |
if self._handler_fn: |
713 |
self._handler_fn(signum, frame)
|
714 |
|
715 |
|
716 |
class FieldSet(object): |
717 |
"""A simple field set.
|
718 |
|
719 |
Among the features are:
|
720 |
- checking if a string is among a list of static string or regex objects
|
721 |
- checking if a whole list of string matches
|
722 |
- returning the matching groups from a regex match
|
723 |
|
724 |
Internally, all fields are held as regular expression objects.
|
725 |
|
726 |
"""
|
727 |
def __init__(self, *items): |
728 |
self.items = [re.compile("^%s$" % value) for value in items] |
729 |
|
730 |
def Extend(self, other_set): |
731 |
"""Extend the field set with the items from another one"""
|
732 |
self.items.extend(other_set.items)
|
733 |
|
734 |
def Matches(self, field): |
735 |
"""Checks if a field matches the current set
|
736 |
|
737 |
@type field: str
|
738 |
@param field: the string to match
|
739 |
@return: either None or a regular expression match object
|
740 |
|
741 |
"""
|
742 |
for m in itertools.ifilter(None, (val.match(field) for val in self.items)): |
743 |
return m
|
744 |
return None |
745 |
|
746 |
def NonMatching(self, items): |
747 |
"""Returns the list of fields not matching the current set
|
748 |
|
749 |
@type items: list
|
750 |
@param items: the list of fields to check
|
751 |
@rtype: list
|
752 |
@return: list of non-matching fields
|
753 |
|
754 |
"""
|
755 |
return [val for val in items if not self.Matches(val)] |