Merge pull request #3223 from ostcar/many_restricted_data

Speed up WS connection

CHANGELOG

@@ -42,6 +42,8 @@ Core:
   pdf [#3184, #3207, #3208].
 - Fixing error when clearing empty chat [#3199].
 - Added notify system [#3212].
+- Enhanced performance esp. for server restart and first connection of all
+  clients by refactorting autoupdate, Collection and AccessPermission [#3223].
 
 General:
 - Switched from npm to Yarn [#3188].

openslides/agenda/access_permissions.py

@@ -1,5 +1,6 @@
 from ..utils.access_permissions import BaseAccessPermissions
 from ..utils.auth import has_perm
+from ..utils.collection import Collection
 
 
 class ItemAccessPermissions(BaseAccessPermissions):
@@ -22,37 +23,71 @@ class ItemAccessPermissions(BaseAccessPermissions):
 
     # TODO: In the following method we use full_data['is_hidden'] but this can be out of date.
 
-    def get_restricted_data(self, full_data, user):
+    def get_restricted_data(self, container, user):
         """
         Returns the restricted serialized data for the instance prepared
         for the user.
+
+        We remove comments for non admins/managers and a lot of fields of
+        hidden items for users without permission to see hidden items.
         """
+        def filtered_data(full_data, blocked_keys):
+            """
+            Returns a new dict like full_data but with all blocked_keys removed.
+            """
+            whitelist = full_data.keys() - blocked_keys
+            return {key: full_data[key] for key in whitelist}
+
+        # Expand full_data to a list if it is not one.
+        full_data = container.get_full_data() if isinstance(container, Collection) else [container.get_full_data()]
+
+        # Parse data.
         if has_perm(user, 'agenda.can_see'):
-            if full_data['is_hidden'] and not has_perm(user, 'agenda.can_see_hidden_items'):
+            if has_perm(user, 'agenda.can_manage') and has_perm(user, 'agenda.can_see_hidden_items'):
-                # The data is hidden but the user isn't allowed to see it. Jst pass
+                # Managers with special permission can see everything.
-                # the whitelisted keys so the list of speakers is provided regardless.
+                data = full_data
-                whitelist = (
+            elif has_perm(user, 'agenda.can_see_hidden_items'):
+                # Non managers with special permission can see everything but comments.
+                blocked_keys = ('comment',)
+                data = [filtered_data(full, blocked_keys) for full in full_data]
+            else:
+                # Users without special permissin for hidden items.
+
+                # In hidden case managers and non managers see only some fields
+                # so that list of speakers is provided regardless.
+                blocked_keys_hidden_case = full_data[0].keys() - (
                     'id',
                     'title',
                     'speakers',
                     'speaker_list_closed',
-                    'content_object',)
+                    'content_object')
-                data = {}
+
-                for key in full_data.keys():
+                # In non hidden case managers see everything and non managers see
-                    if key in whitelist:
+                # everything but comments.
-                        data[key] = full_data[key]
-            else:
                 if has_perm(user, 'agenda.can_manage'):
-                    data = full_data
+                    blocked_keys_non_hidden_case = []
                 else:
-                    # Strip out item comments for unprivileged users.
+                    blocked_keys_non_hidden_case = ('comment',)
-                    data = {}
+
-                    for key in full_data.keys():
+                data = []
-                        if key != 'comment':
+                for full in full_data:
-                            data[key] = full_data[key]
+                    if full['is_hidden']:
+                        data.append(filtered_data(full, blocked_keys_hidden_case))
                     else:
-            data = None
+                        data.append(filtered_data(full, blocked_keys_non_hidden_case))
-        return data
+        else:
+            data = []
+
+        # Reduce result to a single item or None if it was not a collection at
+        # the beginning of the method.
+        if isinstance(container, Collection):
+            restricted_data = data
+        elif data:
+            restricted_data = data[0]
+        else:
+            restricted_data = None
+
+        return restricted_data
 
     def get_projector_data(self, full_data):
         """

openslides/agenda/signals.py

@@ -54,20 +54,15 @@ def get_permission_change_data(sender, permissions, **kwargs):
             break
 
 
-def is_user_data_required(sender, request_user, user_data, **kwargs):
+def is_user_data_required(sender, request_user, **kwargs):
     """
-    Returns True if request user can see the agenda and user_data is required
+    Returns all user ids that are displayed as speakers in any agenda item
-    to be displayed as speaker.
+    if request_user can see the agenda. This function may return an empty
+    set.
     """
-    result = False
+    speakers = set()
     if has_perm(request_user, 'agenda.can_see'):
         for item_collection_element in Collection(Item.get_collection_string()).element_generator():
             full_data = item_collection_element.get_full_data()
-            for speaker in full_data['speakers']:
+            speakers.update(speaker['user_id'] for speaker in full_data['speakers'])
-                if user_data['id'] == speaker['user_id']:
+    return speakers
-                    result = True
-                    break
-            else:
-                continue
-            break
-    return result

openslides/assignments/access_permissions.py

@@ -1,5 +1,6 @@
 from ..utils.access_permissions import BaseAccessPermissions
 from ..utils.auth import has_perm
+from ..utils.collection import Collection
 
 
 class AssignmentAccessPermissions(BaseAccessPermissions):
@@ -24,20 +25,38 @@ class AssignmentAccessPermissions(BaseAccessPermissions):
             serializer_class = AssignmentShortSerializer
         return serializer_class
 
-    def get_restricted_data(self, full_data, user):
+    def get_restricted_data(self, container, user):
         """
         Returns the restricted serialized data for the instance prepared
         for the user. Removes unpublished polls for non admins so that they
         only get a result like the AssignmentShortSerializer would give them.
         """
+        # Expand full_data to a list if it is not one.
+        full_data = container.get_full_data() if isinstance(container, Collection) else [container.get_full_data()]
+
+        # Parse data.
         if has_perm(user, 'assignments.can_see') and has_perm(user, 'assignments.can_manage'):
             data = full_data
         elif has_perm(user, 'assignments.can_see'):
-            data = full_data.copy()
+            # Exclude unpublished polls.
-            data['polls'] = [poll for poll in data['polls'] if poll['published']]
+            data = []
+            for full in full_data:
+                full_copy = full.copy()
+                full_copy['polls'] = [poll for poll in full['polls'] if poll['published']]
+                data.append(full_copy)
         else:
-            data = None
+            data = []
-        return data
+
+        # Reduce result to a single item or None if it was not a collection at
+        # the beginning of the method.
+        if isinstance(container, Collection):
+            restricted_data = data
+        elif data:
+            restricted_data = data[0]
+        else:
+            restricted_data = None
+
+        return restricted_data
 
     def get_projector_data(self, full_data):
         """

openslides/assignments/signals.py

@@ -16,30 +16,17 @@ def get_permission_change_data(sender, permissions=None, **kwargs):
             yield from assignments_app.get_startup_elements()
 
 
-def is_user_data_required(sender, request_user, user_data, **kwargs):
+def is_user_data_required(sender, request_user, **kwargs):
     """
-    Returns True if request user can see assignments and user_data is required
+    Returns all user ids that are displayed as candidates (including poll
-    to be displayed as candidates (including poll options).
+    options) in any assignment if request_user can see assignments. This
+    function may return an empty set.
     """
-    result = False
+    candidates = set()
     if has_perm(request_user, 'assignments.can_see'):
         for assignment_collection_element in Collection(Assignment.get_collection_string()).element_generator():
             full_data = assignment_collection_element.get_full_data()
-            for related_user in full_data['assignment_related_users']:
+            candidates.update(related_user['user_id'] for related_user in full_data['assignment_related_users'])
-                if user_data['id'] == related_user['user_id']:
-                    result = True
-                    break
-            else:
             for poll in full_data['polls']:
-                    for option in poll['options']:
+                candidates.update(option['candidate_id'] for option in poll['options'])
-                        if user_data['id'] == option['candidate_id']:
+    return candidates
-                            result = True
-                            break
-                    else:
-                        continue
-                    break
-                else:
-                    continue
-                break
-            break
-    return result

openslides/core/signals.py

@@ -52,16 +52,14 @@ def get_permission_change_data(sender, permissions, **kwargs):
                 yield Collection(core_app.get_model('ChatMessage').get_collection_string())
 
 
-def is_user_data_required(sender, request_user, user_data, **kwargs):
+def is_user_data_required(sender, request_user, **kwargs):
     """
-    Returns True if request user can use chat and user_data is required
+    Returns all user ids that are displayed as chatters if request_user can
-    to be displayed as chatter.
+    use the chat. This function may return an empty set.
     """
-    result = False
+    chatters = set()
     if has_perm(request_user, 'core.can_use_chat'):
         for chat_message_collection_element in Collection(ChatMessage.get_collection_string()).element_generator():
             full_data = chat_message_collection_element.get_full_data()
-            if user_data['id'] == full_data['user_id']:
+            chatters.add(full_data['user_id'])
-                result = True
+    return chatters
-                break
-    return result

openslides/mediafiles/access_permissions.py

@@ -1,5 +1,6 @@
 from ..utils.access_permissions import BaseAccessPermissions
 from ..utils.auth import has_perm
+from ..utils.collection import Collection
 
 
 class MediafileAccessPermissions(BaseAccessPermissions):
@@ -20,13 +21,30 @@ class MediafileAccessPermissions(BaseAccessPermissions):
 
         return MediafileSerializer
 
-    def get_restricted_data(self, full_data, user):
+    def get_restricted_data(self, container, user):
         """
         Returns the restricted serialized data for the instance prepared
-        for the user.
+        for the user. Removes hidden mediafiles for  some users.
         """
-        data = None
+        # Expand full_data to a list if it is not one.
-        if has_perm(user, 'mediafiles.can_see'):
+        full_data = container.get_full_data() if isinstance(container, Collection) else [container.get_full_data()]
-            if (not full_data['hidden'] or has_perm(user, 'mediafiles.can_see_hidden')):
+
+        # Parse data.
+        if has_perm(user, 'mediafiles.can_see') and has_perm(user, 'mediafiles.can_see_hidden'):
             data = full_data
-        return data
+        elif has_perm(user, 'mediafiles.can_see'):
+            # Exclude hidden mediafiles.
+            data = [full for full in full_data if not full['hidden']]
+        else:
+            data = []
+
+        # Reduce result to a single item or None if it was not a collection at
+        # the beginning of the method.
+        if isinstance(container, Collection):
+            restricted_data = data
+        elif data:
+            restricted_data = data[0]
+        else:
+            restricted_data = None
+
+        return restricted_data

openslides/mediafiles/signals.py

@@ -16,16 +16,15 @@ def get_permission_change_data(sender, permissions=None, **kwargs):
             yield from mediafiles_app.get_startup_elements()
 
 
-def is_user_data_required(sender, request_user, user_data, **kwargs):
+def is_user_data_required(sender, request_user, **kwargs):
     """
-    Returns True if request user can see mediafiles and user_data is required
+    Returns all user ids that are displayed as uploaders in any mediafile
-    to be displayed as uploader.
+    if request_user can see mediafiles. This function may return an empty
+    set.
     """
-    result = False
+    uploaders = set()
     if has_perm(request_user, 'mediafiles.can_see'):
         for mediafile_collection_element in Collection(Mediafile.get_collection_string()).element_generator():
             full_data = mediafile_collection_element.get_full_data()
-            if user_data['id'] == full_data['uploader_id']:
+            uploaders.add(full_data['uploader_id'])
-                result = True
+    return uploaders
-                break
-    return result

openslides/motions/access_permissions.py

@@ -1,11 +1,9 @@
 from copy import deepcopy
 
-from django.contrib.auth import get_user_model
-
 from ..core.config import config
 from ..utils.access_permissions import BaseAccessPermissions
 from ..utils.auth import has_perm
-from ..utils.collection import CollectionElement
+from ..utils.collection import Collection, CollectionElement
 
 
 class MotionAccessPermissions(BaseAccessPermissions):
@@ -26,53 +24,77 @@ class MotionAccessPermissions(BaseAccessPermissions):
 
         return MotionSerializer
 
-    def get_restricted_data(self, full_data, user):
+    def get_restricted_data(self, container, user):
         """
         Returns the restricted serialized data for the instance prepared for
         the user. Removes motion if the user has not the permission to see
         the motion in this state. Removes non public comment fields for
-        some unauthorized users.
+        some unauthorized users. Ensures that a user can only see his own
+        personal notes.
         """
-        if isinstance(user, get_user_model()):
+        # Expand full_data to a list if it is not one.
-            # Converts a user object to a collection element.
+        full_data = container.get_full_data() if isinstance(container, Collection) else [container.get_full_data()]
-            # from_instance can not be used because the user serializer loads
-            # the group from the db. So each call to from_instance(user) consts
-            # one db query.
-            user = CollectionElement.from_values('users/user', user.id)
 
+        # Parse data.
+        if has_perm(user, 'motions.can_see'):
+            # TODO: Refactor this after personal_notes system is refactored.
+            data = []
+            for full in full_data:
+                # Check if user is submitter of this motion.
                 if isinstance(user, CollectionElement):
-            is_submitter = user.get_full_data()['id'] in full_data.get('submitters_id', [])
+                    is_submitter = user.get_full_data()['id'] in full.get('submitters_id', [])
                 else:
-            # Anonymous users can not be submitters
+                    # Anonymous users can not be submitters.
                     is_submitter = False
 
-        required_permission_to_see = full_data['state_required_permission_to_see']
+                # Check see permission for this motion.
-        data = None
+                required_permission_to_see = full['state_required_permission_to_see']
-        if has_perm(user, 'motions.can_see'):
+                permission = (
-            if (not required_permission_to_see or
+                    not required_permission_to_see or
                     has_perm(user, required_permission_to_see) or
                     has_perm(user, 'motions.can_manage') or
-                    is_submitter):
+                    is_submitter)
-                if has_perm(user, 'motions.can_see_and_manage_comments') or not full_data.get('comments'):
+
-                    data = full_data
+                # Parse single motion.
+                if permission:
+                    if has_perm(user, 'motions.can_see_and_manage_comments') or not full.get('comments'):
+                        # Provide access to all fields.
+                        motion = full
                     else:
-                    data = deepcopy(full_data)
+                        # Set private comment fields to None.
+                        full_copy = deepcopy(full)
                         for i, field in enumerate(config['motions_comments']):
                             if not field.get('public'):
                                 try:
-                                data['comments'][i] = None
+                                    full_copy['comments'][i] = None
                                 except IndexError:
                                     # No data in range. Just do nothing.
                                     pass
+                        motion = full_copy
+
                     # Now filter personal notes.
-                data = data.copy()
+                    motion = motion.copy()
-                data['personal_notes'] = []
+                    motion['personal_notes'] = []
                     if user is not None:
-                    for personal_note in full_data.get('personal_notes', []):
+                        for personal_note in full.get('personal_notes', []):
                             if personal_note.get('user_id') == user.id:
-                            data['personal_notes'].append(personal_note)
+                                motion['personal_notes'].append(personal_note)
                                 break
-        return data
+
+                    data.append(motion)
+        else:
+            data = []
+
+        # Reduce result to a single item or None if it was not a collection at
+        # the beginning of the method.
+        if isinstance(container, Collection):
+            restricted_data = data
+        elif data:
+            restricted_data = data[0]
+        else:
+            restricted_data = None
+
+        return restricted_data
 
     def get_projector_data(self, full_data):
         """

openslides/motions/signals.py

@@ -118,16 +118,16 @@ def get_permission_change_data(sender, permissions, **kwargs):
             yield from motions_app.get_startup_elements()
 
 
-def is_user_data_required(sender, request_user, user_data, **kwargs):
+def is_user_data_required(sender, request_user, **kwargs):
     """
-    Returns True if request user can see motions and user_data is required
+    Returns all user ids that are displayed as as submitter or supporter in
-    to be displayed as motion submitter or supporter.
+    any motion if request_user can see motions. This function may return an
+    empty set.
     """
-    result = False
+    submitters_supporters = set()
     if has_perm(request_user, 'motions.can_see'):
         for motion_collection_element in Collection(Motion.get_collection_string()).element_generator():
             full_data = motion_collection_element.get_full_data()
-            if user_data['id'] in full_data['submitters_id'] or user_data['id'] in full_data['supporters_id']:
+            submitters_supporters.update(full_data['submitters_id'])
-                result = True
+            submitters_supporters.update(full_data['supporters_id'])
-                break
+    return submitters_supporters
-    return result

openslides/users/access_permissions.py

@@ -3,6 +3,7 @@ from django.contrib.auth.models import AnonymousUser
 from ..core.signals import user_data_required
 from ..utils.access_permissions import BaseAccessPermissions
 from ..utils.auth import anonymous_is_enabled, has_perm
+from ..utils.collection import Collection
 
 
 class UserAccessPermissions(BaseAccessPermissions):
@@ -23,7 +24,7 @@ class UserAccessPermissions(BaseAccessPermissions):
 
         return UserFullSerializer
 
-    def get_restricted_data(self, full_data, user):
+    def get_restricted_data(self, container, user):
         """
         Returns the restricted serialized data for the instance prepared
         for the user. Removes several fields for non admins so that they do
@@ -31,57 +32,75 @@ class UserAccessPermissions(BaseAccessPermissions):
         """
         from .serializers import USERCANSEESERIALIZER_FIELDS, USERCANSEEEXTRASERIALIZER_FIELDS
 
-        NO_DATA = 0
+        def filtered_data(full_data, whitelist):
-        LITTLE_DATA = 1
+            """
-        MANY_DATA = 2
+            Returns a new dict like full_data but only with whitelisted keys.
-        FULL_DATA = 3
+            """
+            return {key: full_data[key] for key in whitelist}
+
+        # Expand full_data to a list if it is not one.
+        full_data = container.get_full_data() if isinstance(container, Collection) else [container.get_full_data()]
+
+        # We have four sets of data to be sent:
+        # * full data i. e. all fields,
+        # * many data i. e. all fields but not the default password,
+        # * little data i. e. all fields but not the default password, comments and active status,
+        # * no data.
+
+        # Prepare field set for users with "many" data and with "little" data.
+        many_data_fields = set(USERCANSEEEXTRASERIALIZER_FIELDS)
+        many_data_fields.add('groups_id')
+        many_data_fields.discard('groups')
+        litte_data_fields = set(USERCANSEESERIALIZER_FIELDS)
+        litte_data_fields.add('groups_id')
+        litte_data_fields.discard('groups')
 
         # Check user permissions.
         if has_perm(user, 'users.can_see_name'):
             if has_perm(user, 'users.can_see_extra_data'):
                 if has_perm(user, 'users.can_manage'):
-                    case = FULL_DATA
+                    data = full_data
                 else:
-                    case = MANY_DATA
+                    data = [filtered_data(full, many_data_fields) for full in full_data]
             else:
-                case = LITTLE_DATA
+                data = [filtered_data(full, litte_data_fields) for full in full_data]
-        elif user is not None and user.id == full_data.get('id'):
-            # An authenticated user without the permission to see users tries
-            # to see himself.
-            case = LITTLE_DATA
         else:
-            # Now check if the user to be sent out is required by any app e. g.
+            # Build a list of users, that can be seen without any permissions (with little fields).
-            # as motion submitter or assignment candidate.
+
+            user_ids = set()
+
+            # Everybody can see himself. Also everybody can see every user
+            # that is required e. g. as speaker, motion submitter or
+            # assignment candidate.
+
+            # Add oneself.
+            if user is not None:
+                user_ids.add(user.id)
+
+            # Get a list of all users, that are required by another app.
             receiver_responses = user_data_required.send(
                 sender=self.__class__,
-                request_user=user,
+                request_user=user)
-                user_data=full_data)
             for receiver, response in receiver_responses:
-                if response:
+                user_ids.update(response)
-                    case = LITTLE_DATA
-                    break
-            else:
-                case = NO_DATA
 
-        # Setup data.
+            # Parse data.
-        if case == FULL_DATA:
+            data = [
-            data = full_data
+                filtered_data(full, litte_data_fields)
-        elif case == NO_DATA:
+                for full
-            data = None
+                in full_data
+                if full['id'] in user_ids]
+
+        # Reduce result to a single item or None if it was not a collection at
+        # the beginning of the method.
+        if isinstance(container, Collection):
+            restricted_data = data
+        elif data:
+            restricted_data = data[0]
         else:
-            # case in (LITTLE_DATA, ḾANY_DATA)
+            restricted_data = None
-            if case == MANY_DATA:
+
-                fields = USERCANSEEEXTRASERIALIZER_FIELDS
+        return restricted_data
-            else:
-                # case == LITTLE_DATA
-                fields = USERCANSEESERIALIZER_FIELDS
-            # Let only some fields pass this method.
-            data = {}
-            for base_key in fields:
-                for key in (base_key, base_key + '_id'):
-                    if key in full_data.keys():
-                        data[key] = full_data[key]
-        return data
 
     def get_projector_data(self, full_data):
         """

openslides/users/migrations/0004_personalnote.py

@@ -3,7 +3,6 @@
 from __future__ import unicode_literals
 
 import django.db.models.deletion
-
 from django.conf import settings
 from django.db import migrations, models
 

openslides/utils/access_permissions.py

@@ -1,5 +1,6 @@
 from django.dispatch import Signal
 
+from .collection import Collection
 from .dispatch import SignalConnectMetaClass
 
 
@@ -56,14 +57,17 @@ class BaseAccessPermissions(object, metaclass=SignalConnectMetaClass):
         """
         return self.get_serializer_class(user=None)(instance).data
 
-    def get_restricted_data(self, full_data, user):
+    def get_restricted_data(self, container, user):
         """
         Returns the restricted serialized data for the instance prepared
         for the user.
 
-        Returns None if the user has no read access. Returns reduced data
+        The argument container should be a CollectionElement or a
-        if the user has limited access. Default: Returns full data if the
+        Collection. The type of the return value is a dictionary or a list
-        user has read access to model instances.
+        according to the given type (or None). Returns None or an empty
+        list if the user has no read access. Returns reduced data if the
+        user has limited access. Default: Returns full data if the user has
+        read access to model instances.
 
         Hint: You should override this method if your get_serializer_class()
         method returns different serializers for different users or if you
@@ -71,7 +75,9 @@ class BaseAccessPermissions(object, metaclass=SignalConnectMetaClass):
         retrieve() or list().
         """
         if self.check_permissions(user):
-            data = full_data
+            data = container.get_full_data()
+        elif isinstance(container, Collection):
+            data = []
         else:
             data = None
         return data

openslides/utils/autoupdate.py

@@ -6,14 +6,13 @@ from collections import Iterable, defaultdict
 from channels import Channel, Group
 from channels.asgi import get_channel_layer
 from channels.auth import channel_session_user, channel_session_user_from_http
-from django.apps import apps
 from django.core.exceptions import ObjectDoesNotExist
 from django.db import transaction
 
 from ..core.config import config
 from ..core.models import Projector
 from .auth import has_perm, user_to_collection_user
-from .cache import websocket_user_cache
+from .cache import startup_cache, websocket_user_cache
 from .collection import Collection, CollectionElement, CollectionElementList
 
 
@@ -42,6 +41,28 @@ def send_or_wait(send_func, *args, **kwargs):
         )
 
 
+def format_for_autoupdate(collection_string, id, action, data=None):
+    """
+    Returns a dict that can be used for autoupdate.
+    """
+    if not data:
+        # If the data is None or is empty, then the action has to be deleted,
+        # even when it says diffrently. This can happen when the object is not
+        # deleted, but the user has no permission to see it.
+        action = 'deleted'
+
+    output = {
+        'collection': collection_string,
+        'id': id,
+        'action': action,
+    }
+
+    if action != 'deleted':
+        output['data'] = data
+
+    return output
+
+
 @channel_session_user_from_http
 def ws_add_site(message):
     """
@@ -60,21 +81,31 @@ def ws_add_site(message):
     send_or_wait(message.reply_channel.send, {'accept': True})
 
     # Collect all elements that shoud be send to the client when the websocket
-    # connection is established
+    # connection is established.
-    output = []
-    for app in apps.get_app_configs():
-        try:
-            # Get the method get_startup_elements() from an app.
-            # This method has to return an iterable of Collection objects.
-            get_startup_elements = app.get_startup_elements
-        except AttributeError:
-            # Skip apps that do not implement get_startup_elements
-            continue
-        for collection in get_startup_elements():
     user = user_to_collection_user(message.user.id)
-            output.extend(collection.as_autoupdate_for_user(user))
+    output = []
+    for collection in startup_cache.get_collections():
+        access_permissions = collection.get_access_permissions()
+        restricted_data = access_permissions.get_restricted_data(collection, user)
 
-    # Send all data. If there is no data, then only accept the connection
+        if collection.collection_string == 'core/config':
+            id_key = 'key'
+        else:
+            id_key = 'id'
+
+        for data in restricted_data:
+            if data is None:
+                # We do not want to send 'deleted' objects on startup.
+                # That's why we skip such data.
+                continue
+            output.append(
+                format_for_autoupdate(
+                    collection_string=collection.collection_string,
+                    id=data[id_key],
+                    action='changed',
+                    data=data))
+
+    # Send all data.
     if output:
         send_or_wait(message.reply_channel.send, {'text': json.dumps(output)})
 
@@ -338,9 +369,13 @@ def send_autoupdate(collection_elements):
     Helper function, that sends collection_elements through a channel to the
     autoupdate system.
 
+    Before sending the startup_cache is cleared because it is possibly out of
+    date.
+
     Does nothing if collection_elements is empty.
     """
     if collection_elements:
+        startup_cache.clear()
         send_or_wait(
             Channel('autoupdate.send_data').send,
             collection_elements.as_channels_message())

openslides/utils/cache.py

@@ -2,6 +2,7 @@ from collections import defaultdict
 
 from channels import Group
 from channels.sessions import session_for_reply_channel
+from django.apps import apps
 from django.core.cache import cache, caches
 
 
@@ -184,6 +185,62 @@ class DjangoCacheWebsocketUserCache(BaseWebsocketUserCache):
         cache.set(self.get_cache_key(), data)
 
 
+class StartupCache:
+    """
+    Cache of all data that are required when a client connects via websocket.
+    """
+    cache_key = "full_data_startup_cache"
+
+    def build(self):
+        """
+        Generate the cache by going through all apps. Returns a dict where the
+        key is the collection string and the value a list of the full_data from
+        the collection elements.
+        """
+        cache_data = {}
+        for app in apps.get_app_configs():
+            try:
+                # Get the method get_startup_elements() from an app.
+                # This method has to return an iterable of Collection objects.
+                get_startup_elements = app.get_startup_elements
+            except AttributeError:
+                # Skip apps that do not implement get_startup_elements.
+                continue
+
+            for collection in get_startup_elements():
+                cache_data[collection.collection_string] = [
+                    collection_element.get_full_data()
+                    for collection_element
+                    in collection.element_generator()]
+
+        cache.set(self.cache_key, cache_data, 86400)
+        return cache_data
+
+    def clear(self):
+        """
+        Clears the cache.
+        """
+        cache.delete(self.cache_key)
+
+    def get_collections(self):
+        """
+        Generator that returns all cached Collections.
+
+        The data is read from the cache if it exists. It builds the cache if it
+        does not exists.
+        """
+        from .collection import Collection
+        data = cache.get(self.cache_key)
+        if data is None:
+            # The cache does not exist.
+            data = self.build()
+        for collection_string, full_data in data.items():
+            yield Collection(collection_string, full_data)
+
+
+startup_cache = StartupCache()
+
+
 def use_redis_cache():
     """
     Returns True if Redis is used als caching backend.

openslides/utils/collection.py

@@ -100,21 +100,27 @@ class CollectionElement:
         Only for internal use. Do not use it directly. Use as_autoupdate_for_user()
         or as_autoupdate_for_projector().
         """
-        output = {
+        from .autoupdate import format_for_autoupdate
-            'collection': self.collection_string,
+
-            'id': self.id,
+        # TODO: Revert this after get_projector_data is also enhanced like get_restricted_data.
-            'action': 'deleted' if self.is_deleted() else 'changed',
+        if method == 'get_restricted_data':
-        }
+            container = self
+        else:
+            container = self.get_full_data()
+        # End of hack
+
         if not self.is_deleted():
             data = getattr(self.get_access_permissions(), method)(
-                self.get_full_data(),
+                container,
                 *args)
-            if data is None:
-                # The user is not allowed to see this element. Set action to deleted.
-                output['action'] = 'deleted'
         else:
-                output['data'] = data
+            data = None
-        return output
+
+        return format_for_autoupdate(
+            collection_string=self.collection_string,
+            id=self.id,
+            action='deleted' if self.is_deleted() else 'changed',
+            data=data)
 
     def as_autoupdate_for_user(self, user):
         """
@@ -143,9 +149,7 @@ class CollectionElement:
         The argument `user` can be anything, that is allowd as argument for
         utils.auth.has_perm().
         """
-        return self.get_access_permissions().get_restricted_data(
+        return self.get_access_permissions().get_restricted_data(self, user)
-            self.get_full_data(),
-            user)
 
     def get_model(self):
         """
@@ -286,8 +290,15 @@ class Collection:
     Represents all elements of one collection.
     """
 
-    def __init__(self, collection_string):
+    def __init__(self, collection_string, full_data=None):
+        """
+        Initiates a Collection. A collection_string has to be given. If
+        full_data (a list of dictionaries) is not given the method
+        get_full_data() exposes all data by iterating over all
+        CollectionElements.
+        """
         self.collection_string = collection_string
+        self.full_data = full_data
 
     def get_cache_key(self, raw=False):
         """
@@ -307,10 +318,18 @@ class Collection:
         """
         return get_model_from_collection_string(self.collection_string)
 
+    def get_access_permissions(self):
+        """
+        Returns the get_access_permissions object for the this collection.
+        """
+        return self.get_model().get_access_permissions()
+
     def element_generator(self):
         """
         Generator that yields all collection_elements of this collection.
         """
+        # TODO: This method should use self.full_data if it already exists.
+
         # Get all cache keys.
         ids = self.get_all_ids()
         cache_keys = [
@@ -355,10 +374,23 @@ class Collection:
                 for instance in query.filter(pk__in=missing_ids):
                     yield CollectionElement.from_instance(instance)
 
+    def get_full_data(self):
+        """
+        Returns a list of dictionaries with full_data of all collection
+        elements.
+        """
+        if self.full_data is None:
+            self.full_data = [
+                collection_element.get_full_data()
+                for collection_element
+                in self.element_generator()]
+        return self.full_data
+
     def as_autoupdate_for_projector(self):
         """
         Returns a list of dictonaries to send them to the projector.
         """
+        # TODO: This method is only used in one case. Remove it.
         output = []
         for collection_element in self.element_generator():
             content = collection_element.as_autoupdate_for_projector()
@@ -374,6 +406,7 @@ class Collection:
         The argument `user` can be anything, that is allowd as argument for
         utils.auth.has_perm().
         """
+        # TODO: This method is not used. Remove it.
         output = []
         for collection_element in self.element_generator():
             content = collection_element.as_autoupdate_for_user(user)

tests/unit/utils/test_collection.py

@@ -128,7 +128,7 @@ class TestCollectionElement(TestCase):
              'id': 42,
              'action': 'changed',
              'data': 'restricted_data'})
-        collection_element.get_full_data.assert_called_once_with()
+        collection_element.get_full_data.assert_not_called()
 
     def test_as_autoupdate_for_user_no_permission(self):
         with patch.object(collection.CollectionElement, 'get_full_data'):
@@ -143,7 +143,7 @@ class TestCollectionElement(TestCase):
             {'collection': 'testmodule/model',
              'id': 42,
              'action': 'deleted'})
-        collection_element.get_full_data.assert_called_once_with()
+        collection_element.get_full_data.assert_not_called()
 
     def test_as_autoupdate_for_user_deleted(self):
         collection_element = collection.CollectionElement.from_values('testmodule/model', 42, deleted=True)