Sync only missing blocks on cold import

= Add eth_node_fingerprint to block that can be imitated by both hot and cold imports
- Only sync missing blocks (blocks that are missing or don't share a fingerprint) on cold import
- Set block is_final status after import

db/migrations/1525464568_add_eth_node_fingerprint_to_blocks.down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE blocks
+  DROP COLUMN eth_node_fingerprint;

db/migrations/1525464568_add_eth_node_fingerprint_to_blocks.up.sql

@@ -0,0 +1,14 @@
+BEGIN;
+
+ALTER TABLE blocks
+  ADD COLUMN eth_node_fingerprint VARCHAR(128);
+
+UPDATE blocks
+  SET eth_node_fingerprint = (
+    SELECT eth_node_id FROM eth_nodes WHERE eth_nodes.id = blocks.eth_node_id
+  );
+
+ALTER TABLE blocks
+  ALTER COLUMN eth_node_fingerprint SET NOT NULL;
+
+COMMIT;

db/schema.sql

@@ -83,7 +83,8 @@ CREATE TABLE public.blocks (
     miner character varying(42),
     extra_data character varying,
     reward double precision,
-    uncles_reward double precision
+    uncles_reward double precision,
+    eth_node_fingerprint character varying(128) NOT NULL
 );