1 files changed, 127 insertions, 0 deletions
diff --git a/testing/xpcshell/node-ws/lib/buffer-util.js b/testing/xpcshell/node-ws/lib/buffer-util.js
new file mode 100644
index 0000000000..df75955467
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/buffer-util.js
@@ -0,0 +1,127 @@
+'use strict';
+
+const { EMPTY_BUFFER } = require('./constants');
+
+/**
+ * Merges an array of buffers into a new buffer.
+ *
+ * @param {Buffer[]} list The array of buffers to concat
+ * @param {Number} totalLength The total length of buffers in the list
+ * @return {Buffer} The resulting buffer
+ * @public
+ */
+function concat(list, totalLength) {
+  if (list.length === 0) return EMPTY_BUFFER;
+  if (list.length === 1) return list[0];
+
+  const target = Buffer.allocUnsafe(totalLength);
+  let offset = 0;
+
+  for (let i = 0; i < list.length; i++) {
+    const buf = list[i];
+    target.set(buf, offset);
+    offset += buf.length;
+  }
+
+  if (offset < totalLength) return target.slice(0, offset);
+
+  return target;
+}
+
+/**
+ * Masks a buffer using the given mask.
+ *
+ * @param {Buffer} source The buffer to mask
+ * @param {Buffer} mask The mask to use
+ * @param {Buffer} output The buffer where to store the result
+ * @param {Number} offset The offset at which to start writing
+ * @param {Number} length The number of bytes to mask.
+ * @public
+ */
+function _mask(source, mask, output, offset, length) {
+  for (let i = 0; i < length; i++) {
+    output[offset + i] = source[i] ^ mask[i & 3];
+  }
+}
+
+/**
+ * Unmasks a buffer using the given mask.
+ *
+ * @param {Buffer} buffer The buffer to unmask
+ * @param {Buffer} mask The mask to use
+ * @public
+ */
+function _unmask(buffer, mask) {
+  for (let i = 0; i < buffer.length; i++) {
+    buffer[i] ^= mask[i & 3];
+  }
+}
+
+/**
+ * Converts a buffer to an `ArrayBuffer`.
+ *
+ * @param {Buffer} buf The buffer to convert
+ * @return {ArrayBuffer} Converted buffer
+ * @public
+ */
+function toArrayBuffer(buf) {
+  if (buf.byteLength === buf.buffer.byteLength) {
+    return buf.buffer;
+  }
+
+  return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
+}
+
+/**
+ * Converts `data` to a `Buffer`.
+ *
+ * @param {*} data The data to convert
+ * @return {Buffer} The buffer
+ * @throws {TypeError}
+ * @public
+ */
+function toBuffer(data) {
+  toBuffer.readOnly = true;
+
+  if (Buffer.isBuffer(data)) return data;
+
+  let buf;
+
+  if (data instanceof ArrayBuffer) {
+    buf = Buffer.from(data);
+  } else if (ArrayBuffer.isView(data)) {
+    buf = Buffer.from(data.buffer, data.byteOffset, data.byteLength);
+  } else {
+    buf = Buffer.from(data);
+    toBuffer.readOnly = false;
+  }
+
+  return buf;
+}
+
+module.exports = {
+  concat,
+  mask: _mask,
+  toArrayBuffer,
+  toBuffer,
+  unmask: _unmask
+};
+
+/* istanbul ignore else  */
+if (!process.env.WS_NO_BUFFER_UTIL) {
+  try {
+    const bufferUtil = require('bufferutil');
+
+    module.exports.mask = function (source, mask, output, offset, length) {
+      if (length < 48) _mask(source, mask, output, offset, length);
+      else bufferUtil.mask(source, mask, output, offset, length);
+    };
+
+    module.exports.unmask = function (buffer, mask) {
+      if (buffer.length < 32) _unmask(buffer, mask);
+      else bufferUtil.unmask(buffer, mask);
+    };
+  } catch (e) {
+    // Continue regardless of the error.
+  }
+}