优化rating计算速度

hydro/lib/sha1.js

@@ -0,0 +1,10 @@
+const crypto = require('crypto');
+/**
+ * @param {any} content
+ * @return {string}
+ */
+global.Hydro.lib.sha1 = module.exports = (content) => {
+    const hash = crypto.createHash('sha1');
+    hash.update(content);
+    return hash.digest('hex');
+};