Close voting after 30 days, delete vote records

This makes it so that posts (both topics and comments) can no longer be
voted on after they're over 30 days old. An hourly cronjob makes this
"official" by updating a flag on the post indicating that voting is
closed. The daily clean_private_data script then deletes all individual
vote records for posts with closed voting, and the triggers on the
voting tables have been updated to not decrement the vote totals when
these deletions happen.

The net result of this is that Tildes only stores users' votes for a
maximum of 30 days, removing a lot of sensitive/private data that builds
up over the long term.

salt/salt/cronjobs.sls

@@ -1,5 +1,12 @@
 {% from 'common.jinja2' import app_dir, app_username, bin_dir %}
 
+close-voting-cronjob:
+  cron.present:
+    - name: {{ bin_dir }}/python -c "from scripts.close_voting_on_old_posts import close_voting_on_old_posts; close_voting_on_old_posts('{{ app_dir }}/{{ pillar['ini_file'] }}')"
+    - user: {{ app_username }}
+    - hour: '*'
+    - minute: 3
+
 data-cleanup-cronjob:
   cron.present:
     - name: {{ bin_dir }}/python -c "from scripts.clean_private_data import clean_all_data; clean_all_data('{{ app_dir }}/{{ pillar['ini_file'] }}')"

tildes/alembic/versions/4d352e61a468_add_is_voting_closed_to_comments_.py

@@ -0,0 +1,129 @@
+"""Add is_voting_closed to comments and topics
+
+Revision ID: 4d352e61a468
+Revises: 879588c5729d
+Create Date: 2019-11-15 23:58:09.613684
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "4d352e61a468"
+down_revision = "879588c5729d"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.add_column(
+        "comments",
+        sa.Column(
+            "is_voting_closed", sa.Boolean(), server_default="false", nullable=False
+        ),
+    )
+    op.create_index(
+        op.f("ix_comments_is_voting_closed"),
+        "comments",
+        ["is_voting_closed"],
+        unique=False,
+    )
+    op.add_column(
+        "topics",
+        sa.Column(
+            "is_voting_closed", sa.Boolean(), server_default="false", nullable=False
+        ),
+    )
+    op.create_index(
+        op.f("ix_topics_is_voting_closed"), "topics", ["is_voting_closed"], unique=False
+    )
+
+    op.execute(
+        """
+        CREATE OR REPLACE FUNCTION update_comment_num_votes() RETURNS TRIGGER AS $$
+        BEGIN
+            IF (TG_OP = 'INSERT') THEN
+                UPDATE comments
+                    SET num_votes = num_votes + 1
+                    WHERE comment_id = NEW.comment_id;
+            ELSIF (TG_OP = 'DELETE') THEN
+                UPDATE comments
+                    SET num_votes = num_votes - 1
+                    WHERE comment_id = OLD.comment_id
+                        AND is_voting_closed = FALSE;
+            END IF;
+
+            RETURN NULL;
+        END
+        $$ LANGUAGE plpgsql;
+        """
+    )
+
+    op.execute(
+        """
+        CREATE OR REPLACE FUNCTION update_topic_num_votes() RETURNS TRIGGER AS $$
+        BEGIN
+            IF (TG_OP = 'INSERT') THEN
+                UPDATE topics
+                    SET num_votes = num_votes + 1
+                    WHERE topic_id = NEW.topic_id;
+            ELSIF (TG_OP = 'DELETE') THEN
+                UPDATE topics
+                    SET num_votes = num_votes - 1
+                    WHERE topic_id = OLD.topic_id
+                        AND is_voting_closed = FALSE;
+            END IF;
+
+            RETURN NULL;
+        END
+        $$ LANGUAGE plpgsql;
+        """
+    )
+
+
+def downgrade():
+    op.drop_index(op.f("ix_topics_is_voting_closed"), table_name="topics")
+    op.drop_column("topics", "is_voting_closed")
+    op.drop_index(op.f("ix_comments_is_voting_closed"), table_name="comments")
+    op.drop_column("comments", "is_voting_closed")
+
+    op.execute(
+        """
+        CREATE OR REPLACE FUNCTION update_comment_num_votes() RETURNS TRIGGER AS $$
+        BEGIN
+            IF (TG_OP = 'INSERT') THEN
+                UPDATE comments
+                    SET num_votes = num_votes + 1
+                    WHERE comment_id = NEW.comment_id;
+            ELSIF (TG_OP = 'DELETE') THEN
+                UPDATE comments
+                    SET num_votes = num_votes - 1
+                    WHERE comment_id = OLD.comment_id;
+            END IF;
+
+            RETURN NULL;
+        END
+        $$ LANGUAGE plpgsql;
+        """
+    )
+
+    op.execute(
+        """
+        CREATE OR REPLACE FUNCTION update_topic_num_votes() RETURNS TRIGGER AS $$
+        BEGIN
+            IF (TG_OP = 'INSERT') THEN
+                UPDATE topics
+                    SET num_votes = num_votes + 1
+                    WHERE topic_id = NEW.topic_id;
+            ELSIF (TG_OP = 'DELETE') THEN
+                UPDATE topics
+                    SET num_votes = num_votes - 1
+                    WHERE topic_id = OLD.topic_id;
+            END IF;
+
+            RETURN NULL;
+        END
+        $$ LANGUAGE plpgsql;
+        """
+    )

tildes/scripts/clean_private_data.py

@@ -4,7 +4,6 @@
 """Script for cleaning up private/deleted data.
 
 Other things that should probably be added here eventually:
-    - Delete individual votes on comments/topics after voting has been closed
     - Delete which users labeled comments after labeling has been closed
     - Delete old used invite codes (30 days after used?)
 """
@@ -65,6 +64,7 @@ class DataCleaner:
 
         self.delete_old_log_entries()
         self.delete_old_topic_visits()
+        self.delete_old_votes()
 
         self.clean_old_deleted_comments()
         self.clean_old_deleted_topics()
@@ -96,6 +96,25 @@ class DataCleaner:
         self.db_session.commit()
         logging.info(f"Deleted {deleted} old topic visits.")
 
+    def delete_old_votes(self) -> None:
+        """Delete individual votes on posts with their voting closed."""
+        self.db_session.execute(
+            """
+            DELETE FROM comment_votes USING comments
+            WHERE comments.comment_id = comment_votes.comment_id
+                AND comments.is_voting_closed = TRUE
+            """
+        )
+        self.db_session.execute(
+            """
+            DELETE FROM topic_votes USING topics
+            WHERE topics.topic_id = topic_votes.topic_id
+                AND topics.is_voting_closed = TRUE
+            """
+        )
+
+        self.db_session.commit()
+
     def clean_old_deleted_comments(self) -> None:
         """Clean the data of old deleted comments.
 

tildes/scripts/close_voting_on_old_posts.py

@@ -0,0 +1,31 @@
+# Copyright (c) 2019 Tildes contributors <code@tildes.net>
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+"""Simple script to "officially" close voting on old posts.
+
+This script should be set up to run regularly (such as every hour). It's not totally
+essential since the application can generally prevent voting using the same logic, but
+the more often it's run, the more correct the is_voting_closed column will be.
+"""
+
+from tildes.lib.database import get_session_from_config
+from tildes.lib.datetime import utc_now
+from tildes.models.comment import Comment, VOTING_PERIOD as COMMENT_VOTING_PERIOD
+from tildes.models.topic import Topic, VOTING_PERIOD as TOPIC_VOTING_PERIOD
+
+
+def close_voting_on_old_posts(config_path: str) -> None:
+    """Update is_voting_closed column on all posts older than the voting period."""
+    db_session = get_session_from_config(config_path)
+
+    db_session.query(Comment).filter(
+        Comment.created_time < utc_now() - COMMENT_VOTING_PERIOD,
+        Comment._is_voting_closed == False,  # noqa
+    ).update({"_is_voting_closed": True}, synchronize_session=False)
+
+    db_session.query(Topic).filter(
+        Topic.created_time < utc_now() - TOPIC_VOTING_PERIOD,
+        Topic._is_voting_closed == False,  # noqa
+    ).update({"_is_voting_closed": True}, synchronize_session=False)
+
+    db_session.commit()

tildes/scss/modules/_btn.scss

@@ -83,7 +83,6 @@
   align-items: center;
   justify-content: space-between;
   margin: 0;
-  padding: 0 0.2rem;
 
   // The buttons don't need to be spaced widely on a desktop
   @media (min-width: $size-md) {

tildes/scss/modules/_comment.scss

@@ -166,8 +166,7 @@
 
 .comment-votes {
   font-size: 0.6rem;
-  font-weight: bold;
-  margin: 0 0.4rem;
+  margin: 0.2rem 0.4rem;
 }
 
 .is-comment-by-op {

tildes/sql/init/triggers/comment_votes/comments.sql

@@ -8,9 +8,12 @@ BEGIN
             SET num_votes = num_votes + 1
             WHERE comment_id = NEW.comment_id;
     ELSIF (TG_OP = 'DELETE') THEN
+        -- Exclude comments with closed voting from decrements so that individual vote
+        -- records can be deleted while retaining the final vote total.
         UPDATE comments
             SET num_votes = num_votes - 1
-            WHERE comment_id = OLD.comment_id;
+            WHERE comment_id = OLD.comment_id
+                AND is_voting_closed = FALSE;
     END IF;
 
     RETURN NULL;

tildes/sql/init/triggers/topic_votes/topics.sql

@@ -8,9 +8,12 @@ BEGIN
             SET num_votes = num_votes + 1
             WHERE topic_id = NEW.topic_id;
     ELSIF (TG_OP = 'DELETE') THEN
+        -- Exclude topics with closed voting from decrements so that individual vote
+        -- records can be deleted while retaining the final vote total.
         UPDATE topics
             SET num_votes = num_votes - 1
-            WHERE topic_id = OLD.topic_id;
+            WHERE topic_id = OLD.topic_id
+                AND is_voting_closed = FALSE;
     END IF;
 
     RETURN NULL;

tildes/tildes/models/comment/__init__.py

@@ -1,6 +1,6 @@
 """Contains models related to comments."""
 
-from .comment import Comment, EDIT_GRACE_PERIOD
+from .comment import Comment, EDIT_GRACE_PERIOD, VOTING_PERIOD
 from .comment_bookmark import CommentBookmark
 from .comment_label import CommentLabel
 from .comment_notification import CommentNotification

tildes/tildes/models/comment/comment.py

@@ -31,6 +31,9 @@ else:
 # edits inside this period after creation will not mark the comment as edited
 EDIT_GRACE_PERIOD = timedelta(minutes=5)
 
+# comments can no longer be voted on when they're older than this
+VOTING_PERIOD = timedelta(days=30)
+
 
 class Comment(DatabaseModel):
     """Model for a comment on the site.
@@ -38,7 +41,7 @@ class Comment(DatabaseModel):
     Trigger behavior:
       Incoming:
         - num_votes will be incremented and decremented by insertions and deletions in
-          comment_votes.
+          comment_votes (but no decrementing if voting is closed).
       Outgoing:
         - Inserting or deleting rows, or updating is_deleted/is_removed to change
           visibility will increment or decrement num_comments accordingly on the
@@ -88,6 +91,9 @@ class Comment(DatabaseModel):
     rendered_html: str = Column(Text, nullable=False)
     excerpt: str = Column(Text, nullable=False, server_default="")
     num_votes: int = Column(Integer, nullable=False, server_default="0", index=True)
+    _is_voting_closed: bool = Column(
+        "is_voting_closed", Boolean, nullable=False, server_default="false", index=True
+    )
     search_tsv: Any = deferred(Column(TSVECTOR))
 
     user: User = relationship("User", lazy=False, innerjoin=True)
@@ -170,10 +176,14 @@ class Comment(DatabaseModel):
 
         # vote:
         #  - removed comments can't be voted on by anyone
+        #  - if voting has been closed, nobody can vote
         #  - otherwise, logged-in users except the author can vote
         if self.is_removed:
             acl.append((Deny, Everyone, "vote"))
 
+        if self.is_voting_closed:
+            acl.append((Deny, Everyone, "vote"))
+
         acl.append((Deny, self.user_id, "vote"))
         acl.append((Allow, Authenticated, "vote"))
 
@@ -259,6 +269,21 @@ class Comment(DatabaseModel):
 
         return f"{self.topic.permalink}#comment-{self.parent_comment_id36}"
 
+    @property
+    def is_voting_closed(self) -> bool:
+        """Return whether voting on the comment is closed.
+
+        Note that if any logic is changed in here, the close_voting_on_old posts script
+        should be updated to match.
+        """
+        if self._is_voting_closed:
+            return True
+
+        if self.age > VOTING_PERIOD:
+            return True
+
+        return False
+
     @property
     def label_counts(self) -> Counter:
         """Counter for number of times each label is on this comment."""

tildes/tildes/models/comment/comment_vote.py

@@ -22,7 +22,7 @@ class CommentVote(DatabaseModel):
     Trigger behavior:
       Outgoing:
         - Inserting or deleting a row will increment or decrement the num_votes column
-          for the relevant comment.
+          for the relevant comment (but no decrementing if its voting is closed).
     """
 
     __tablename__ = "comment_votes"

tildes/tildes/models/topic/__init__.py

@@ -1,6 +1,6 @@
 """Contains models related to topics."""
 
-from .topic import EDIT_GRACE_PERIOD, Topic
+from .topic import EDIT_GRACE_PERIOD, Topic, VOTING_PERIOD
 from .topic_bookmark import TopicBookmark
 from .topic_query import TopicQuery
 from .topic_schedule import TopicSchedule

tildes/tildes/models/topic/topic.py

@@ -47,6 +47,9 @@ else:
 # edits inside this period after creation will not mark the topic as edited
 EDIT_GRACE_PERIOD = timedelta(minutes=5)
 
+# topics can no longer be voted on when they're older than this
+VOTING_PERIOD = timedelta(days=30)
+
 
 class Topic(DatabaseModel):
     """Model for a topic on the site.
@@ -54,7 +57,7 @@ class Topic(DatabaseModel):
     Trigger behavior:
       Incoming:
         - num_votes will be incremented and decremented by insertions and deletions in
-          topic_votes.
+          topic_votes (but no decrementing if voting is closed).
         - num_comments will be incremented and decremented by insertions, deletions, and
           updates to is_deleted in comments.
         - last_activity_time will be updated by insertions, deletions, and updates to
@@ -123,6 +126,9 @@ class Topic(DatabaseModel):
     )
     num_comments: int = Column(Integer, nullable=False, server_default="0", index=True)
     num_votes: int = Column(Integer, nullable=False, server_default="0", index=True)
+    _is_voting_closed: bool = Column(
+        "is_voting_closed", Boolean, nullable=False, server_default="false", index=True
+    )
     tags: List[str] = Column(TagList, nullable=False, server_default="{}")
     is_official: bool = Column(Boolean, nullable=False, server_default="false")
     is_locked: bool = Column(Boolean, nullable=False, server_default="false")
@@ -235,7 +241,7 @@ class Topic(DatabaseModel):
     def _update_creation_metric(self) -> None:
         incr_counter("topics", type=self.topic_type.name.lower())
 
-    def __acl__(self) -> Sequence[Tuple[str, Any, str]]:
+    def __acl__(self) -> Sequence[Tuple[str, Any, str]]:  # noqa
         """Pyramid security ACL."""
         acl = []
 
@@ -274,10 +280,14 @@ class Topic(DatabaseModel):
 
         # vote:
         #  - removed topics can't be voted on by anyone
+        #  - if voting has been closed, nobody can vote
         #  - otherwise, logged-in users except the author can vote
         if self.is_removed:
             acl.append((Deny, Everyone, "vote"))
 
+        if self.is_voting_closed:
+            acl.append((Deny, Everyone, "vote"))
+
         acl.append((Deny, self.user_id, "vote"))
         acl.append((Allow, Authenticated, "vote"))
 
@@ -402,6 +412,21 @@ class Topic(DatabaseModel):
         """Return whether the topic is marked as a spoiler."""
         return self.has_tag("spoiler")
 
+    @property
+    def is_voting_closed(self) -> bool:
+        """Return whether voting on the topic is closed.
+
+        Note that if any logic is changed in here, the close_voting_on_old posts script
+        should be updated to match.
+        """
+        if self._is_voting_closed:
+            return True
+
+        if self.age > VOTING_PERIOD:
+            return True
+
+        return False
+
     def has_tag(self, check_tag: str) -> bool:
         """Return whether the topic has a tag or any sub-tag of it."""
         if check_tag in self.tags:

tildes/tildes/models/topic/topic_vote.py

@@ -22,7 +22,7 @@ class TopicVote(DatabaseModel):
     Trigger behavior:
       Outgoing:
         - Inserting or deleting a row will increment or decrement the num_votes column
-          for the relevant topic.
+          for the relevant topic (but no decrementing if its voting is closed).
     """
 
     __tablename__ = "topic_votes"

tildes/tildes/templates/macros/comments.jinja2

@@ -144,12 +144,12 @@
         {{ comment.rendered_html|safe }}
       </div>
 
-      {# Show votes at the bottom only if the viewer is logged out #}
-      {% if not request.user and comment.num_votes > 0 %}
-        <div class="comment-votes">{{ pluralize(comment.num_votes, "vote") }}</div>
-      {% endif %}
-
       <menu class="btn-post">
+        {# Show non-button vote count if the viewer can't vote and it's not their comment #}
+        {% if not request.has_permission("vote", comment) and comment.num_votes > 0 and comment.user != request.user %}
+          <div class="comment-votes">{{ pluralize(comment.num_votes, "vote") }}</div>
+        {% endif %}
+
         {% if request.has_permission('vote', comment) %}
           {% if comment.user_voted is defined and comment.user_voted %}
             <li><button class="btn-post-action btn-post-action-used" name="unvote"