From ab80874fa59736505c0cce9894c9e8518fdb94db Mon Sep 17 00:00:00 2001
From: tanjinzhou <415800467@qq.com>
Date: Sun, 27 Sep 2020 16:05:53 +0800
Subject: [PATCH] feat: update virtuallist

---
 antdv-demo                                    |  2 +-
 components/vc-virtual-list/utils/CacheMap.js  | 19 +++++++++++++++++++
 components/vc-virtual-list/utils/isFirefox.js |  3 +++
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 components/vc-virtual-list/utils/CacheMap.js
 create mode 100644 components/vc-virtual-list/utils/isFirefox.js

diff --git a/antdv-demo b/antdv-demo
index 83ab203d1..955716e4e 160000
--- a/antdv-demo
+++ b/antdv-demo
@@ -1 +1 @@
-Subproject commit 83ab203d1ab9861132f6efd1e74015507c0e45f6
+Subproject commit 955716e4e9533bc628c651d6ba6c8d1eb9b21a9d
diff --git a/components/vc-virtual-list/utils/CacheMap.js b/components/vc-virtual-list/utils/CacheMap.js
new file mode 100644
index 000000000..ffca328f7
--- /dev/null
+++ b/components/vc-virtual-list/utils/CacheMap.js
@@ -0,0 +1,19 @@
+// Firefox has low performance of map.
+class CacheMap {
+  maps;
+
+  constructor() {
+    this.maps = {};
+    this.maps.prototype = null;
+  }
+
+  set(key, value) {
+    this.maps[key] = value;
+  }
+
+  get(key) {
+    return this.maps[key];
+  }
+}
+
+export default CacheMap;
diff --git a/components/vc-virtual-list/utils/isFirefox.js b/components/vc-virtual-list/utils/isFirefox.js
new file mode 100644
index 000000000..871180a78
--- /dev/null
+++ b/components/vc-virtual-list/utils/isFirefox.js
@@ -0,0 +1,3 @@
+const isFF = typeof navigator === 'object' && /Firefox/i.test(navigator.userAgent);
+
+export default isFF;