sql-migrate: interactions notify - length to octet_length

src/utils/model/sql_migrations/001020_interactions_notification.sql

@@ -0,0 +1,51 @@
+-- +migrate Down
+
+-- +migrate Up
+
+-- +migrate StatementBegin
+CREATE OR REPLACE FUNCTION notify_l2_interaction() RETURNS trigger AS $$
+DECLARE
+	is_queue_full boolean; 
+	is_forwarder_listening boolean;
+   	is_too_big boolean;
+    src_tx_id text;
+	payload text;
+BEGIN
+	-- Notify only upon L2 changes
+	IF NEW.source != 'redstone-sequencer' THEN
+		RETURN NEW;
+	END IF;
+
+	-- Skip if there's a risk pg_notify would fail
+	SELECT pg_notification_queue_usage() > 0.9 INTO is_queue_full;
+	IF is_queue_full THEN
+		-- pg_notify would fail upon full queue, so let's avoid this situation
+		RETURN NEW;
+	END IF;
+
+	-- Skip if there's no forwarder listening
+	SELECT EXISTS(SELECT pid FROM pg_stat_activity WHERE query='listen "interactions"') INTO is_forwarder_listening;
+	IF NOT is_forwarder_listening THEN
+		-- Forwarder is down, it will get this interaction when it comes back up
+		RETURN NEW;
+	END IF;
+
+    -- Get the source tx id
+    SELECT contracts.src_tx_id FROM contracts WHERE contracts.contract_id = NEW.contract_id INTO src_tx_id;
+
+	-- Neglect big interactions
+	SELECT jsonb_build_object(
+            'contractId', NEW.contract_id,
+			'interaction', NEW.interaction,
+            'srcTxId', src_tx_id
+		)::TEXT INTO payload;
+	SELECT octet_length(payload) > 7999 INTO is_too_big;
+
+	IF NOT is_too_big THEN
+		PERFORM pg_notify('interactions', payload);
+	END IF;
+
+	RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+-- +migrate StatementEnd