add string.hashCode

xuezu · xuezu · commit 523e29400c44 · 2015-08-23T12:57:14.000+08:00
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,6 @@
+node_modules
+logs
+test
+.*
+!.gitignore
+!.npmignore
diff --git a/.npmignore b/.npmignore
@@ -0,0 +1 @@
+test
diff --git a/index.js b/index.js
@@ -0,0 +1,40 @@
+/**
+ * - index.js
+ * @author luckydrq(drqzju@gmail.com)
+ */
+'use strict';
+
+var util = require('core-util-is');
+
+/**
+ * return a hash code of this string
+ * @ref http://blog.csdn.net/exceptional_derek/article/details/9074137
+ * @param {String} str
+ * @return {Number}
+ * @api public
+ */
+exports.hashCode = function(str) {
+  if (util.isFunction(str.hashCode)) {
+    return str.hashCode();
+  }
+
+  str = new String(str);
+  str.value = str.split('').map(function(c) { return c.charCodeAt(0); });
+  str.offset = 0;
+  str.hash = 0;
+  str.hashCode = function() {
+    var count = this.length;
+    var h = this.hash;
+    if (h === 0 && count > 0) {
+      var off = this.offset;
+      var val = this.value;
+      var len = count;
+      for (var i = 0; i < len; i++) {
+        h = 31 * h + val[off++];
+      }
+      this.hash = h;
+    }
+    return h;
+  };
+  return str.hashCode();
+};
diff --git a/package.json b/package.json
@@ -0,0 +1,29 @@
+{
+  "name": "string-extras",
+  "version": "0.0.1",
+  "description": "Extra utilities for string",
+  "keywords": [
+    "string",
+    "utility",
+    "extra"
+  ],
+  "maintainers": [
+    {
+      "name": "Deng Ruoqi",
+      "email": "drqzju@gmail.com"
+    }
+  ],
+  "scripts": {
+    "test": "mocha ./test/*.test.js"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git@github.com:luckydrq/string-extras.git"
+  },
+  "dependencies": {
+    "core-util-is": "~1.0.1"
+  },
+  "devDependencies": {
+    "mocha": "~2.2.5"
+  }
+}
