add rollout strategy

src/isInRollout.ts

@@ -0,0 +1,77 @@
+/* eslint-disable no-fallthrough */
+
+import { cInfo } from './core';
+
+/* eslint-disable no-bitwise */
+function murmurhash3_32_gc(key: string, seed = 0) {
+  let remainder, bytes, h1, h1b, c1, c2, k1, i;
+
+  remainder = key.length & 3; // key.length % 4
+  bytes = key.length - remainder;
+  h1 = seed;
+  c1 = 0xcc9e2d51;
+  c2 = 0x1b873593;
+  i = 0;
+
+  while (i < bytes) {
+    k1 =
+      (key.charCodeAt(i) & 0xff) |
+      ((key.charCodeAt(++i) & 0xff) << 8) |
+      ((key.charCodeAt(++i) & 0xff) << 16) |
+      ((key.charCodeAt(++i) & 0xff) << 24);
+    ++i;
+
+    ((k1 & 0xffff) * c1 + ((((k1 >>> 16) * c1) & 0xffff) << 16)) & 0xffffffff;
+    k1 = (k1 << 15) | (k1 >>> 17);
+    k1 =
+      ((k1 & 0xffff) * c2 + ((((k1 >>> 16) * c2) & 0xffff) << 16)) & 0xffffffff;
+
+    h1 ^= k1;
+    h1 = (h1 << 13) | (h1 >>> 19);
+    h1b =
+      ((h1 & 0xffff) * 5 + ((((h1 >>> 16) * 5) & 0xffff) << 16)) & 0xffffffff;
+    h1 = (h1b & 0xffff) + 0x6b64 + ((((h1b >>> 16) + 0xe654) & 0xffff) << 16);
+  }
+
+  k1 = 0;
+
+  switch (remainder) {
+    case 3:
+      k1 ^= (key.charCodeAt(i + 2) & 0xff) << 16;
+    case 2:
+      k1 ^= (key.charCodeAt(i + 1) & 0xff) << 8;
+    case 1:
+      k1 ^= key.charCodeAt(i) & 0xff;
+
+      k1 =
+        ((k1 & 0xffff) * c1 + ((((k1 >>> 16) * c1) & 0xffff) << 16)) &
+        0xffffffff;
+      k1 = (k1 << 15) | (k1 >>> 17);
+      k1 =
+        ((k1 & 0xffff) * c2 + ((((k1 >>> 16) * c2) & 0xffff) << 16)) &
+        0xffffffff;
+      h1 ^= k1;
+  }
+
+  h1 ^= key.length;
+
+  h1 ^= h1 >>> 16;
+  h1 =
+    ((h1 & 0xffff) * 0x85ebca6b +
+      ((((h1 >>> 16) * 0x85ebca6b) & 0xffff) << 16)) &
+    0xffffffff;
+  h1 ^= h1 >>> 13;
+  h1 =
+    ((h1 & 0xffff) * 0xc2b2ae35 +
+      ((((h1 >>> 16) * 0xc2b2ae35) & 0xffff) << 16)) &
+    0xffffffff;
+  h1 ^= h1 >>> 16;
+
+  return h1 >>> 0;
+}
+
+const intForUUID = murmurhash3_32_gc(cInfo.uuid);
+
+export function isInRollout(rollout: number) {
+  return intForUUID % 100 < rollout;
+}