From 8a06ac7fb9a8ee23530bcb385c06af917e2fdc55 Mon Sep 17 00:00:00 2001
From: Matchu <matchu1993@gmail.com>
Date: Tue, 24 Nov 2020 21:03:45 -0800
Subject: [PATCH] perf upgrade for UserItemsPage
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I knowingly wrote this less performant at first. And indeed, it was slow—like 2sec of main thread time! Turn that O(mn) into O(n) pls!
---
 .../__snapshots__/User.test.js.snap           |  4 +--
 src/server/types/User.js                      | 25 +++++++++++++------
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/server/query-tests/__snapshots__/User.test.js.snap b/src/server/query-tests/__snapshots__/User.test.js.snap
index b5c6116..a17d006 100644
--- a/src/server/query-tests/__snapshots__/User.test.js.snap
+++ b/src/server/query-tests/__snapshots__/User.test.js.snap
@@ -69,7 +69,7 @@ Object {
             "name": "Blue Jelly Tiara",
           },
         ],
-        "name": "(Not in a list)",
+        "name": "Not in a list",
         "ownsOrWantsItems": "OWNS",
       },
       Object {
@@ -81,7 +81,7 @@ Object {
             "name": "Altador Cup Background - Kreludor",
           },
         ],
-        "name": "(Not in a list)",
+        "name": "Not in a list",
         "ownsOrWantsItems": "WANTS",
       },
     ],
diff --git a/src/server/types/User.js b/src/server/types/User.js
index 5c521a3..9372cda 100644
--- a/src/server/types/User.js
+++ b/src/server/types/User.js
@@ -136,12 +136,25 @@ const resolvers = {
         userLoader.load(id),
       ]);
 
+      const hangersByList = new Map(closetLists.map((l) => [l.id, []]));
+      const defaultListOwnedHangers = [];
+      const defaultListWantedHangers = [];
+      for (const hanger of allClosetHangers) {
+        if (hanger.listId) {
+          hangersByList.get(hanger.listId).push(hanger);
+        } else if (hanger.owned) {
+          defaultListOwnedHangers.push(hanger);
+        } else {
+          defaultListWantedHangers.push(hanger);
+        }
+      }
+
       const closetListNodes = closetLists
         .filter((closetList) => isCurrentUser || closetList.visibility >= 1)
         .map((closetList) => ({
           id: closetList.id,
-          items: allClosetHangers
-            .filter((h) => h.listId === closetList.id)
+          items: hangersByList
+            .get(closetList.id)
             .map((h) => ({ id: h.itemId })),
         }));
 
@@ -150,9 +163,7 @@ const resolvers = {
           isDefaultList: true,
           userId: id,
           ownsOrWantsItems: "OWNS",
-          items: allClosetHangers
-            .filter((h) => h.listId == null && h.owned)
-            .map((h) => ({ id: h.itemId })),
+          items: defaultListOwnedHangers.map((h) => ({ id: h.itemId })),
         });
       }
 
@@ -162,9 +173,7 @@ const resolvers = {
           userId: id,
           ownsOrWantsItems: "WANTS",
           isDefaultList: true,
-          items: allClosetHangers
-            .filter((h) => h.listId == null && !h.owned)
-            .map((h) => ({ id: h.itemId })),
+          items: defaultListWantedHangers.map((h) => ({ id: h.itemId })),
         });
       }