Bug 889157 - Uplift Add-on SDK to Firefox r=me

addon-sdk/source/lib/sdk/io/buffer.js

@@ -0,0 +1,82 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+"use strict";
+
+module.metadata = {
+  "stability": "experimental"
+};
+
+
+const { Cc, Ci, CC } = require("chrome");
+const { Class } = require("../core/heritage");
+
+const Transcoder = CC("@mozilla.org/intl/scriptableunicodeconverter",
+                      "nsIScriptableUnicodeConverter");
+
+var Buffer = Class({
+  initialize: function initialize(subject, encoding) {
+    subject = subject ? subject.valueOf() : 0;
+    let length = typeof subject === "number" ? subject : 0;
+    this.encoding = encoding || "utf-8";
+    this.valueOf(Array.isArray(subject) ? subject : new Array(length));
+
+    if (typeof subject === "string") this.write(subject);
+  },
+  get length() {
+    return this.valueOf().length;
+  },
+  get: function get(index) {
+    return this.valueOf()[index];
+  },
+  set: function set(index, value) {
+    return this.valueOf()[index] = value;
+  },
+  valueOf: function valueOf(value) {
+    Object.defineProperty(this, "valueOf", {
+      value: Array.prototype.valueOf.bind(value),
+      configurable: false,
+      writable: false,
+      enumerable: false
+    });
+  },
+  toString: function toString(encoding, start, end) {
+    let bytes = this.valueOf().slice(start || 0, end || this.length);
+    let transcoder = Transcoder();
+    transcoder.charset = String(encoding || this.encoding).toUpperCase();
+    return transcoder.convertFromByteArray(bytes, this.length);
+  },
+  toJSON: function toJSON() {
+    return this.toString()
+  },
+  write: function write(string, offset, encoding) {
+    offset = Math.max(offset || 0, 0);
+    let value = this.valueOf();
+    let transcoder = Transcoder();
+    transcoder.charset = String(encoding || this.encoding).toUpperCase();
+    let bytes = transcoder.convertToByteArray(string, {});
+    value.splice.apply(value, [
+      offset,
+      Math.min(value.length - offset, bytes.length, bytes)
+    ].concat(bytes));
+    return bytes;
+  },
+  slice: function slice(start, end) {
+    return new Buffer(this.valueOf().slice(start, end));
+  },
+  copy: function copy(target, offset, start, end) {
+    offset = Math.max(offset || 0, 0);
+    target = target.valueOf();
+    let bytes = this.valueOf();
+    bytes.slice(Math.max(start || 0, 0), end);
+    target.splice.apply(target, [
+      offset,
+      Math.min(target.length - offset, bytes.length),
+    ].concat(bytes));
+  }
+});
+Buffer.isBuffer = function isBuffer(buffer) {
+  return buffer instanceof Buffer
+};
+exports.Buffer = Buffer;