Added pool_delegations_list variant that calculates bare minimum dele… (

#281)

Added pool_delegations_list variant that calculates bare minimum
delegator data needed by pool_info endpoint, to improve performance of
the latter

Co-authored-by: hodlonaut <[email protected]>

files/grest/rpc/pool/pool_delegators.sql

@@ -66,3 +66,70 @@ END;
 $$;
 
 COMMENT ON FUNCTION grest.pool_delegators IS 'Return information about live delegators for a given pool.'; --noqa: LT01
+
+
+
+
+CREATE OR REPLACE FUNCTION grest.pool_delegators_list(_pool_bech32 text)
+RETURNS TABLE (
+  stake_address character varying,
+  amount text
+)
+LANGUAGE plpgsql
+AS $$
+#variable_conflict use_column
+DECLARE
+  _pool_id bigint;
+BEGIN
+  SELECT id INTO _pool_id FROM pool_hash WHERE pool_hash.view = _pool_bech32;
+
+  RETURN QUERY
+    WITH
+      _all_delegations AS (
+        SELECT
+          sa.id AS stake_address_id,
+          sdc.stake_address,
+          (
+            CASE WHEN sdc.total_balance >= 0
+              THEN sdc.total_balance
+              ELSE 0
+            END
+          ) AS total_balance
+        FROM grest.stake_distribution_cache AS sdc
+        INNER JOIN public.stake_address AS sa ON sa.view = sdc.stake_address
+        WHERE sdc.pool_id = _pool_bech32
+
+        UNION ALL
+
+        -- combine with registered delegations not in stake-dist-cache yet
+        SELECT 
+          z.stake_address_id, z.stake_address, SUM(acc_info.value::numeric) AS total_balance
+        FROM
+          ( 
+            SELECT
+              sa.id AS stake_address_id,
+              sa.view AS stake_address
+            FROM delegation AS d 
+              INNER JOIN stake_address AS sa ON d.addr_id = sa.id and d.pool_hash_id = _pool_id
+              AND NOT EXISTS (SELECT null FROM delegation AS d2 WHERE d2.addr_id = d.addr_id AND d2.id > d.id)
+              AND NOT EXISTS (SELECT null FROM stake_deregistration AS sd WHERE sd.addr_id = d.addr_id AND sd.tx_id > d.tx_id)
+              -- AND NOT grest.is_dangling_delegation(d.id)
+              AND NOT EXISTS (SELECT null FROM grest.stake_distribution_cache AS sdc WHERE sdc.stake_address = sa.view)
+          ) z,
+          LATERAL grest.account_utxos(array[z.stake_address], false) AS acc_info
+        GROUP BY
+          z.stake_address_id,
+          z.stake_address
+      )
+
+    SELECT 
+      ad.stake_address,
+      ad.total_balance::text
+    FROM _all_delegations AS ad;
+
+END;
+$$;
+
+
+COMMENT ON FUNCTION grest.pool_delegators_list IS 'Return brief variant of information about live delegators for a given pool, needed by pool_info endpoint.'; --noqa: LT01
+

files/grest/rpc/pool/pool_info.sql

@@ -127,7 +127,7 @@ BEGIN
         ELSE
           SUM(CASE WHEN pool_delegs.stake_address = ANY(api.owners) THEN amount::numeric ELSE 0 END)::lovelace
         END AS pledge
-      FROM grest.pool_delegators(api.pool_id_bech32) AS pool_delegs
+      FROM grest.pool_delegators_list(api.pool_id_bech32) AS pool_delegs
     ) AS live ON TRUE;
 END;
 $$;