更新

2026-08-11 17:41:36 +08:00
parent cfe4c82c90
commit 03fe4ddf9d
18771 changed files with 3617239 additions and 0 deletions
@@ -0,0 +1,23 @@
+var has = require('./has');
+exports = function(fn) {
+    var hashFn =
+        arguments.length > 1 && arguments[1] !== undefined
+            ? arguments[1]
+            : JSON.stringify;
+    var singleton = function() {
+        var cache = singleton.cache;
+        var address = hashFn.apply(this, arguments);
+        if (has(cache, address)) {
+            return cache[address];
+        }
+        var promise = fn.apply(this, arguments).finally(function() {
+            delete cache[address];
+        });
+        cache[address] = promise;
+        return promise;
+    };
+    singleton.cache = {};
+    return singleton;
+};
+
+module.exports = exports;