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  # Copyright 2011 OpenStack Foundation
  # All Rights Reserved.
  #
  #    Licensed under the Apache License, Version 2.0 (the "License"); you may
  #    not use this file except in compliance with the License. You may obtain
  #    a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  #    License for the specific language governing permissions and limitations
  #    under the License.
  
  import urlparse
  import webob
  
  from nova.api.openstack import extensions
  from nova.api.openstack import wsgi
  from nova.api.openstack import xmlutil
  import nova.context
  from nova import db
  from nova import exception
  from nova.openstack.common.gettextutils import _
  from nova.openstack.common import log as logging
  from nova.openstack.common import strutils
  from nova import quota
  
  
  ALIAS = "os-quota-sets"
  QUOTAS = quota.QUOTAS
  LOG = logging.getLogger(__name__)
  authorize_update = extensions.extension_authorizer('compute',
                                                     'v3:%s:update' % ALIAS)
  authorize_show = extensions.extension_authorizer('compute',
                                                   'v3:%s:show' % ALIAS)
  authorize_delete = extensions.extension_authorizer('compute',
                                                     'v3:%s:delete' % ALIAS)
  authorize_detail = extensions.extension_authorizer('compute',
                                                     'v3:%s:detail' % ALIAS)
  
  
  class QuotaTemplate(xmlutil.TemplateBuilder):
      def construct(self):
          root = xmlutil.TemplateElement('quota_set', selector='quota_set')
          root.set('id')
  
          for resource in QUOTAS.resources:
              elem = xmlutil.SubTemplateElement(root, resource)
              elem.text = resource
  
          return xmlutil.MasterTemplate(root, 1)
  
  
  class QuotaDetailTemplate(xmlutil.TemplateBuilder):
      def construct(self):
          root = xmlutil.TemplateElement('quota_set', selector='quota_set')
          root.set('id')
  
          for resource in QUOTAS.resources:
              elem = xmlutil.SubTemplateElement(root, resource,
                                                selector=resource)
              elem.set('in_use')
              elem.set('reserved')
              elem.set('limit')
  
          return xmlutil.MasterTemplate(root, 1)
  
  
  class QuotaSetsController(object):
  
      def _format_quota_set(self, project_id, quota_set):
          """Convert the quota object to a result dict."""
          quota_set.update(id=project_id)
          return dict(quota_set=quota_set)
  
      def _validate_quota_limit(self, limit, minimum, maximum):
          # NOTE: -1 is a flag value for unlimited
          if limit < -1:
              msg = _("Quota limit must be -1 or greater.")
              raise webob.exc.HTTPBadRequest(explanation=msg)
          if ((limit < minimum) and
             (maximum != -1 or (maximum == -1 and limit != -1))):
              msg = _("Quota limit must greater than %s.") % minimum
              raise webob.exc.HTTPBadRequest(explanation=msg)
          if maximum != -1 and limit > maximum:
              msg = _("Quota limit must less than %s.") % maximum
              raise webob.exc.HTTPBadRequest(explanation=msg)
  
      def _get_quotas(self, context, id, user_id=None, usages=False):
          if user_id:
              values = QUOTAS.get_user_quotas(context, id, user_id,
                                              usages=usages)
          else:
              values = QUOTAS.get_project_quotas(context, id, usages=usages)
  
          if usages:
              return values
          else:
              return dict((k, v['limit']) for k, v in values.items())
  
      @extensions.expected_errors(403)
      @wsgi.serializers(xml=QuotaTemplate)
      def show(self, req, id):
          context = req.environ['nova.context']
          authorize_show(context)
          params = urlparse.parse_qs(req.environ.get('QUERY_STRING', ''))
          user_id = params.get('user_id', [None])[0]
          try:
              nova.context.authorize_project_context(context, id)
              return self._format_quota_set(id,
                      self._get_quotas(context, id, user_id=user_id))
          except exception.NotAuthorized:
              raise webob.exc.HTTPForbidden()
  
      @extensions.expected_errors(403)
      @wsgi.serializers(xml=QuotaDetailTemplate)
      def detail(self, req, id):
          context = req.environ['nova.context']
          authorize_detail(context)
          user_id = req.GET.get('user_id', None)
          try:
              nova.context.authorize_project_context(context, id)
              return self._format_quota_set(id, self._get_quotas(context, id,
                                                                 user_id=user_id,
                                                                 usages=True))
          except exception.NotAuthorized:
              raise webob.exc.HTTPForbidden()
  
      @extensions.expected_errors((400, 403))
      @wsgi.serializers(xml=QuotaTemplate)
      def update(self, req, id, body):
          context = req.environ['nova.context']
          authorize_update(context)
          project_id = id
          params = urlparse.parse_qs(req.environ.get('QUERY_STRING', ''))
          user_id = params.get('user_id', [None])[0]
  
          bad_keys = []
          force_update = False
  
          for key, value in body['quota_set'].items():
              if key not in QUOTAS and key != 'force':
                  bad_keys.append(key)
                  continue
              if key == 'force':
                  force_update = strutils.bool_from_string(value)
              elif key != 'force' and value:
                  try:
                      value = int(value)
                  except (ValueError, TypeError):
                      msg = _("Quota value for key '%(key)s' should be an "
                              "integer.  It is actually type '%(vtype)s'.")
                      msg = msg % {'key': key, 'vtype': type(value)}
                      LOG.warn(msg)
                      raise webob.exc.HTTPBadRequest(explanation=msg)
  
          if len(bad_keys) > 0:
              msg = _("Bad key(s) %s in quota_set") % ",".join(bad_keys)
              raise webob.exc.HTTPBadRequest(explanation=msg)
  
          try:
              settable_quotas = QUOTAS.get_settable_quotas(context, project_id,
                                                           user_id=user_id)
          except exception.NotAuthorized:
              raise webob.exc.HTTPForbidden()
  
          try:
              quotas = self._get_quotas(context, id, user_id=user_id,
                                        usages=True)
          except exception.NotAuthorized:
              raise webob.exc.HTTPForbidden()
  
          LOG.debug(_("Force update quotas: %s"), force_update)
  
          for key, value in body['quota_set'].iteritems():
              if key == 'force' or (not value and value != 0):
                  continue
              # validate whether already used and reserved exceeds the new
              # quota, this check will be ignored if admin want to force
              # update
              value = int(value)
              if force_update is not True and value >= 0:
                  quota_value = quotas.get(key)
                  if quota_value and quota_value['limit'] >= 0:
                      quota_used = (quota_value['in_use'] +
                                    quota_value['reserved'])
                      LOG.debug(_("Quota %(key)s used: %(quota_used)s, "
                                  "value: %(value)s."),
                                {'key': key, 'quota_used': quota_used,
                                 'value': value})
                      if quota_used > value:
                          msg = (_("Quota value %(value)s for %(key)s are "
                                  "less than already used and reserved "
                                  "%(quota_used)s") %
                                  {'value': value, 'key': key,
                                   'quota_used': quota_used})
                          raise webob.exc.HTTPBadRequest(explanation=msg)
  
              minimum = settable_quotas[key]['minimum']
              maximum = settable_quotas[key]['maximum']
              self._validate_quota_limit(value, minimum, maximum)
              try:
                  db.quota_create(context, project_id, key, value,
                                  user_id=user_id)
              except exception.QuotaExists:
                  db.quota_update(context, project_id, key, value,
                                  user_id=user_id)
              except exception.AdminRequired:
                  raise webob.exc.HTTPForbidden()
          return self._format_quota_set(id, self._get_quotas(context, id,
                                                             user_id=user_id))
  
      @extensions.expected_errors(())
      @wsgi.serializers(xml=QuotaTemplate)
      def defaults(self, req, id):
          context = req.environ['nova.context']
          authorize_show(context)
          return self._format_quota_set(id, QUOTAS.get_defaults(context))
  
      @extensions.expected_errors(403)
      @wsgi.response(204)
      def delete(self, req, id):
          context = req.environ['nova.context']
          authorize_delete(context)
          params = urlparse.parse_qs(req.environ.get('QUERY_STRING', ''))
          user_id = params.get('user_id', [None])[0]
          try:
              nova.context.authorize_project_context(context, id)
              if user_id:
                  QUOTAS.destroy_all_by_project_and_user(context,
                                                         id, user_id)
              else:
                  QUOTAS.destroy_all_by_project(context, id)
          except exception.NotAuthorized:
              raise webob.exc.HTTPForbidden()
  
  
  class QuotaSets(extensions.V3APIExtensionBase):
      """Quotas management support."""
  
      name = "Quotas"
      alias = ALIAS
      namespace = "http://docs.openstack.org/compute/ext/os-quotas-sets/api/v3"
      version = 1
  
      def get_resources(self):
          resources = []
  
          res = extensions.ResourceExtension(ALIAS,
                                              QuotaSetsController(),
                                              member_actions={'defaults': 'GET',
                                                              'detail': 'GET'})
          resources.append(res)
  
          return resources
  
      def get_controller_extensions(self):
          return []
  