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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /netwerk/dns/mdns/libmdns/fallback/DataWriter.jsm
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'netwerk/dns/mdns/libmdns/fallback/DataWriter.jsm')
-rw-r--r--netwerk/dns/mdns/libmdns/fallback/DataWriter.jsm98
1 files changed, 98 insertions, 0 deletions
diff --git a/netwerk/dns/mdns/libmdns/fallback/DataWriter.jsm b/netwerk/dns/mdns/libmdns/fallback/DataWriter.jsm
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+++ b/netwerk/dns/mdns/libmdns/fallback/DataWriter.jsm
@@ -0,0 +1,98 @@
+/* -*- Mode: js; js-indent-level: 2; indent-tabs-mode: nil; tab-width: 2 -*- */
+/* 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/. */
+/* jshint esnext: true, moz: true */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = ['DataWriter'];
+
+class DataWriter {
+ constructor(data, maxBytes = 512) {
+ if (typeof data === 'number') {
+ maxBytes = data;
+ data = undefined;
+ }
+
+ this._buffer = new ArrayBuffer(maxBytes);
+ this._data = new Uint8Array(this._buffer);
+ this._cursor = 0;
+
+ if (data) {
+ this.putBytes(data);
+ }
+ }
+
+ get buffer() {
+ return this._buffer.slice(0, this._cursor);
+ }
+
+ get data() {
+ return new Uint8Array(this.buffer);
+ }
+
+ // `data` is `Uint8Array`
+ putBytes(data) {
+ if (this._cursor + data.length > this._data.length) {
+ throw new Error('DataWriter buffer is exceeded');
+ }
+
+ for (let i = 0, length = data.length; i < length; i++) {
+ this._data[this._cursor] = data[i];
+ this._cursor++;
+ }
+ }
+
+ putByte(byte) {
+ if (this._cursor + 1 > this._data.length) {
+ throw new Error('DataWriter buffer is exceeded');
+ }
+
+ this._data[this._cursor] = byte
+ this._cursor++;
+ }
+
+ putValue(value, length) {
+ length = length || 1;
+ if (length == 1) {
+ this.putByte(value);
+ } else {
+ this.putBytes(_valueToUint8Array(value, length));
+ }
+ }
+
+ putLabel(label) {
+ // Eliminate any trailing '.'s in the label (valid in text representation).
+ label = label.replace(/\.$/, '');
+ let parts = label.split('.');
+ parts.forEach((part) => {
+ this.putLengthString(part);
+ });
+ this.putValue(0);
+ }
+
+ putLengthString(string) {
+ if (string.length > 0xff) {
+ throw new Error("String too long.");
+ }
+ this.putValue(string.length);
+ for (let i = 0; i < string.length; i++) {
+ this.putValue(string.charCodeAt(i));
+ }
+ }
+}
+
+/**
+ * @private
+ */
+function _valueToUint8Array(value, length) {
+ let arrayBuffer = new ArrayBuffer(length);
+ let uint8Array = new Uint8Array(arrayBuffer);
+ for (let i = length - 1; i >= 0; i--) {
+ uint8Array[i] = value & 0xff;
+ value = value >> 8;
+ }
+
+ return uint8Array;
+}