refactor: no need for LRU for interval (2.2m parsed/s) (#683)

Author: benjie

packages/graphile-build-pg/src/plugins/PgTypesPlugin.js

@@ -3,8 +3,7 @@ import type { Plugin } from "graphile-build";
 
 import makeGraphQLJSONType from "../GraphQLJSON";
 
-import { parseInterval as rawParseInterval } from "../postgresInterval";
-import LRU from "@graphile/lru";
+import { parseInterval } from "../postgresInterval";
 
 function indent(str) {
   return "  " + str.replace(/\n/g, "\n  ");
@@ -14,17 +13,6 @@ function identity(value) {
   return value;
 }
 
-const parseCache = new LRU({ maxLength: 500 });
-function parseInterval(str) {
-  let result = parseCache.get(str);
-  if (!result) {
-    result = rawParseInterval(str);
-    Object.freeze(result);
-    parseCache.set(str, result);
-  }
-  return result;
-}
-
 export default (function PgTypesPlugin(
   builder,
   {

packages/graphile-build-pg/src/postgresInterval.js

@@ -1,5 +1,14 @@
 // @flow
 
+export type Interval = {
+  years: number,
+  months: number,
+  days: number,
+  hours: number,
+  minutes: number,
+  seconds: number,
+};
+
 // Regexp construction enhanced from `postgres-interval`, which is licensed
 // under the MIT license and is copyright (c) Ben Drucker <bvdrucker@gmail.com>
 // (bendrucker.me).
@@ -15,35 +24,15 @@ const DAY = `${NUMBER}\\s+days?`;
 const TIME = "([+-])?(\\d+):(\\d\\d):(\\d\\d(?:\\.\\d{1,6})?)";
 
 const INTERVAL = new RegExp(
-  "^\\s*" +
+  "^" +
     // All parts of an interval are optional
     [YEAR, MONTH, DAY, TIME].map(str => "(?:" + str + ")?").join("\\s*") +
-    "\\s*$"
+    "$"
 );
 
-export type Interval = {
-  years: number,
-  months: number,
-  days: number,
-  hours: number,
-  minutes: number,
-  seconds: number,
-};
-
 export function parseInterval(interval: string): Interval {
-  if (!interval) {
-    return {
-      years: 0,
-      months: 0,
-      days: 0,
-      hours: 0,
-      minutes: 0,
-      seconds: 0.0,
-    };
-  }
-
   const [, years, months, days, plusMinusTime, hours, minutes, seconds] =
-    INTERVAL.exec(interval) || [];
+    INTERVAL.exec(interval || "") || [];
 
   const timeMultiplier = plusMinusTime === "-" ? -1 : 1;