replace last_delete with next_delete

migrations/versions/e769c033e5c9_replace_last_delete_with_next_delete.py

@@ -0,0 +1,32 @@
+"""replace last_delete with next_delete
+
+Revision ID: e769c033e5c9
+Revises: 6d298e6406f2
+Create Date: 2017-08-14 20:51:02.248343
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = 'e769c033e5c9'
+down_revision = '6d298e6406f2'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.add_column('accounts', sa.Column('next_delete', sa.DateTime(), server_default='epoch', nullable=True))
+    op.execute('UPDATE accounts SET next_delete = last_delete + policy_delete_every;')
+    op.create_index(op.f('ix_accounts_next_delete'), 'accounts', ['next_delete'], unique=False)
+    op.drop_index('ix_accounts_last_delete', table_name='accounts')
+    op.drop_column('accounts', 'last_delete')
+
+
+def downgrade():
+    op.add_column('accounts', sa.Column('last_delete', postgresql.TIMESTAMP(), server_default=sa.text("'1970-01-01 00:00:00'::timestamp without time zone"), autoincrement=False, nullable=True))
+    op.execute('UPDATE accounts SET last__delete = next_delete - policy_delete_every;')
+    op.create_index('ix_accounts_last_delete', 'accounts', ['last_delete'], unique=False)
+    op.drop_index(op.f('ix_accounts_next_delete'), table_name='accounts')
+    op.drop_column('accounts', 'next_delete')

model.py

@@ -5,7 +5,7 @@ from app import db
 from twitter import Twitter, OAuth
 import secrets
 from lib import decompose_interval
-from datetime import timedelta
+from datetime import timedelta, datetime
 
 class TimestampMixin(object):
     created_at = db.Column(db.DateTime, server_default=db.func.now(), nullable=False)
@@ -53,14 +53,17 @@ class Account(TimestampMixin, RemoteIDMixin):
     reported_post_count = db.Column(db.Integer)
 
     last_fetch = db.Column(db.DateTime, server_default='epoch', index=True)
-    last_delete = db.Column(db.DateTime, server_default='epoch', index=True)
     last_refresh = db.Column(db.DateTime, server_default='epoch', index=True)
+    next_delete = db.Column(db.DateTime, server_default='epoch', index=True)
 
     def touch_fetch(self):
         self.last_fetch = db.func.now()
 
     def touch_delete(self):
-        self.last_delete = db.func.now()
+        if(datetime.now() - self.next_delete > 3 * self.delete_every):
+            self.next_delete = db.func.now() + self.delete_every
+        else:
+            self.next_delete += self.delete_every
 
     def touch_refresh(self):
         self.last_refresh = db.func.now()

routes.py

@@ -151,12 +151,12 @@ def enable():
             return render_template('warn.html', message=f"""You've set the time between deleting posts to 0. Every post that matches your expiration rules will be deleted within minutes.
                     { ("That's about " + str(approx) + " posts.") if approx > 0 else "" }
                     Go ahead?""")
-        if g.viewer.account.last_delete < datetime.now() - timedelta(days=365):
+        if g.viewer.account.next_delete < datetime.now() - timedelta(days=365):
             return render_template('warn.html', message="""Once you enable Forget, posts that match your expiration rules will be deleted <b>permanently</b>. We can't bring them back. Make sure that you won't miss them.""")
 
 
     if not g.viewer.account.policy_enabled:
-        g.viewer.account.last_delete = db.func.now()
+        g.viewer.account.next_delete = datetime.now() + g.viewer.account.policy_delete_every
 
     g.viewer.account.policy_enabled = True
     db.session.commit()
@@ -202,6 +202,6 @@ def api_viewer_post_counts():
             last_refresh_rel=lib.interval.relnow(viewer.last_refresh),
             last_fetch=viewer.last_fetch,
             last_fetch_rel=lib.interval.relnow(viewer.last_fetch),
-            last_delete=viewer.last_delete,
-            last_delete_rel=lib.interval.relnow(viewer.last_delete),
+            next_delete=viewer.next_delete,
+            next_delete_rel=lib.interval.relnow(viewer.next_delete),
         )

tasks.py

@@ -127,7 +127,7 @@ def periodic_cleanup():
 @app.task
 def queue_deletes():
     eligible_accounts = Account.query.filter(Account.policy_enabled == True).\
-            filter(Account.last_delete + Account.policy_delete_every < db.func.now())
+            filter(Account.next_delete < db.func.now())
     for account in eligible_accounts:
         delete_from_account.s(account.id).apply_async()
 
@@ -151,6 +151,7 @@ def delete_from_account(account_id):
                 print("deleting all {} eligible posts for {}".format(len(eligible), account))
                 for post in eligible:
                     lib.twitter.delete(post)
+                    account.touch_delete()
             else:
                 post = random.choice(eligible)
                 print("deleting {}".format(post))