初始化

engine/cocos2d/renderer/memop/pool.js

@@ -0,0 +1,59 @@
+export default class Pool {
+  constructor(fn, size) {
+    this._fn = fn;
+    this._idx = size - 1;
+    this._frees = new Array(size);
+
+    for (let i = 0; i < size; ++i) {
+      this._frees[i] = fn();
+    }
+  }
+
+  _expand(size) {
+    let old = this._frees;
+    this._frees = new Array(size);
+
+    let len = size - old.length;
+    for (let i = 0; i < len; ++i) {
+      this._frees[i] = this._fn();
+    }
+
+    for (let i = len, j = 0; i < size; ++i, ++j) {
+      this._frees[i] = old[j];
+    }
+
+    this._idx += len;
+  }
+
+  alloc() {
+    // create some more space (expand by 20%, minimum 1)
+    if (this._idx < 0) {
+      this._expand(Math.round(this._frees.length * 1.2) + 1);
+    }
+
+    let ret = this._frees[this._idx];
+    this._frees[this._idx] = null;
+    --this._idx;
+
+    return ret;
+  }
+
+  free(obj) {
+    ++this._idx;
+    this._frees[this._idx] = obj;
+  }
+
+  /**
+   * 清除对象池。
+   * @param fn 清除回调，对每个释放的对象调用一次。
+   */
+  clear (fn) {
+    for (let i = 0; i <= this._idx; i++) {
+        if (fn) {
+            fn(this._frees[i]);
+        }
+    }
+    this._frees.length = 0;
+    this._idx = -1;
+  }
+}