Merge pull request #19 from vulcanize/state_leaf_remove

Add function to check for state node removal.

db/migrations/00028_add_state_leaf_remove_function.sql

@@ -0,0 +1,20 @@
+-- +goose Up
+-- +goose StatementBegin
+-- returns if a state leaf node was removed within the provided block number
+CREATE OR REPLACE FUNCTION was_state_leaf_removed(key character varying, hash character varying)
+    RETURNS boolean AS $$
+    SELECT state_cids.node_type = 3
+    FROM eth.state_cids
+             INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
+    WHERE state_leaf_key = key
+      AND block_number <= (SELECT block_number
+                           FROM eth.header_cids
+                           WHERE block_hash = hash)
+    ORDER BY block_number DESC LIMIT 1;
+$$
+language sql;
+-- +goose StatementEnd
+
+
+-- +goose Down
+DROP FUNCTION was_state_leaf_removed;

db/schema.sql

@@ -232,6 +232,24 @@ END
 $$;
 
 
+--
+-- Name: was_state_leaf_removed(character varying, character varying); Type: FUNCTION; Schema: public; Owner: -
+--
+
+CREATE FUNCTION public.was_state_leaf_removed(key character varying, hash character varying) RETURNS boolean
+    LANGUAGE sql
+    AS $$
+    SELECT state_cids.node_type = 3
+    FROM eth.state_cids
+             INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
+    WHERE state_leaf_key = key
+      AND block_number <= (SELECT block_number
+                           FROM eth.header_cids
+                           WHERE block_hash = hash)
+    ORDER BY block_number DESC LIMIT 1;
+$$;
+
+
 --
 -- Name: was_state_removed(bytea, bigint, character varying); Type: FUNCTION; Schema: public; Owner: -
 --