1 files changed, 51 insertions, 0 deletions
diff --git a/app/models/loose_foreign_keys/modification_tracker.rb b/app/models/loose_foreign_keys/modification_tracker.rb
new file mode 100644
index 00000000000..6eb04608cd9
--- /dev/null
+++ b/app/models/loose_foreign_keys/modification_tracker.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+module LooseForeignKeys
+  class ModificationTracker
+    MAX_DELETES = 100_000
+    MAX_UPDATES = 50_000
+    MAX_RUNTIME = 3.minutes
+
+    delegate :monotonic_time, to: :'Gitlab::Metrics::System'
+
+    def initialize
+      @delete_count_by_table = Hash.new { |h, k| h[k] = 0 }
+      @update_count_by_table = Hash.new { |h, k| h[k] = 0 }
+      @start_time = monotonic_time
+      @deletes_counter = Gitlab::Metrics.counter(
+        :loose_foreign_key_deletions,
+        'The number of loose foreign key deletions'
+      )
+      @updates_counter = Gitlab::Metrics.counter(
+        :loose_foreign_key_updates,
+        'The number of loose foreign key updates'
+      )
+    end
+
+    def add_deletions(table, count)
+      @delete_count_by_table[table] += count
+      @deletes_counter.increment({ table: table }, count)
+    end
+
+    def add_updates(table, count)
+      @update_count_by_table[table] += count
+      @updates_counter.increment({ table: table }, count)
+    end
+
+    def over_limit?
+      @delete_count_by_table.values.sum >= MAX_DELETES ||
+        @update_count_by_table.values.sum >= MAX_UPDATES ||
+        monotonic_time - @start_time >= MAX_RUNTIME
+    end
+
+    def stats
+      {
+        over_limit: over_limit?,
+        delete_count_by_table: @delete_count_by_table,
+        update_count_by_table: @update_count_by_table,
+        delete_count: @delete_count_by_table.values.sum,
+        update_count: @update_count_by_table.values.sum
+      }
+    end
+  end
+end