1 files changed, 75 insertions, 0 deletions
diff --git a/db/migrate/20181024224956_migrate_account_conversations.rb b/db/migrate/20181024224956_migrate_account_conversations.rb
new file mode 100644
index 000000000..47f7375ba
--- /dev/null
+++ b/db/migrate/20181024224956_migrate_account_conversations.rb
@@ -0,0 +1,75 @@
+class MigrateAccountConversations < ActiveRecord::Migration[5.2]
+  disable_ddl_transaction!
+
+  def up
+    say ''
+    say 'WARNING: This migration may take a *long* time for large instances'
+    say 'It will *not* lock tables for any significant time, but it may run'
+    say 'for a very long time. We will pause for 10 seconds to allow you to'
+    say 'interrupt this migration if you are not ready.'
+    say ''
+
+    10.downto(1) do |i|
+      say "Continuing in #{i} second#{i == 1 ? '' : 's'}...", true
+      sleep 1
+    end
+
+    total        = estimate_rows(local_direct_statuses) + estimate_rows(notifications_about_direct_statuses)
+    migrated     = 0
+    started_time = Time.zone.now
+    last_time    = Time.zone.now
+
+    local_direct_statuses.includes(:account, mentions: :account).find_each do |status|
+      AccountConversation.add_status(status.account, status)
+      migrated += 1
+
+      if Time.zone.now - last_time > 1
+        say_progress(migrated, total, started_time)
+        last_time = Time.zone.now
+      end
+    end
+
+    notifications_about_direct_statuses.includes(:account, mention: { status: [:account, mentions: :account] }).find_each do |notification|
+      AccountConversation.add_status(notification.account, notification.target_status)
+      migrated += 1
+
+      if Time.zone.now - last_time > 1
+        say_progress(migrated, total, started_time)
+        last_time = Time.zone.now
+      end
+    end
+  end
+
+  def down
+  end
+
+  private
+
+  def estimate_rows(query)
+    result = exec_query("EXPLAIN #{query.to_sql}").first
+    result['QUERY PLAN'].scan(/ rows=([\d]+)/).first&.first&.to_i || 0
+  end
+
+  def say_progress(migrated, total, started_time)
+    status = "Migrated #{migrated} rows"
+
+    percentage = 100.0 * migrated / total
+    status += " (~#{sprintf('%.2f', percentage)}%, "
+
+    remaining_time = (100.0 - percentage) * (Time.zone.now - started_time) / percentage
+
+    status += "#{(remaining_time / 60).to_i}:"
+    status += sprintf('%02d', remaining_time.to_i % 60)
+    status += ' remaining)'
+
+    say status, true
+  end
+
+  def local_direct_statuses
+    Status.unscoped.local.where(visibility: :direct)
+  end
+
+  def notifications_about_direct_statuses
+    Notification.joins(mention: :status).where(activity_type: 'Mention', statuses: { visibility: :direct })
+  end
+end