The Tor Browser: addon-sdk/source/lib/sdk/io/buffer.js@129ffea94266 (annotated)

addon-sdk/source/lib/sdk/io/buffer.js@129ffea94266 (annotated)

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

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /* 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'
 };
 /*
  * Encodings supported by TextEncoder/Decoder:
  * utf-8, utf-16le, utf-16be
  * http://encoding.spec.whatwg.org/#interface-textencoder
  *
  * Node however supports the following encodings:
  * ascii, utf-8, utf-16le, usc2, base64, hex
  */
 const { Cu } = require('chrome');
 const { isNumber } = require('sdk/lang/type');
 const { TextEncoder, TextDecoder } = Cu.import('resource://gre/modules/commonjs/toolkit/loader.js', {});
 exports.TextEncoder = TextEncoder;
 exports.TextDecoder = TextDecoder;
 /**
  * Use WeakMaps to work around Bug 929146, which prevents us from adding
  * getters or values to typed arrays
  * https://bugzilla.mozilla.org/show_bug.cgi?id=929146
  */
 const parents = new WeakMap();
 const views = new WeakMap();
 function Buffer(subject, encoding /*, bufferLength */) {
   // Allow invocation without `new` constructor
   if (!(this instanceof Buffer))
     return new Buffer(subject, encoding, arguments[2]);
   var type = typeof(subject);
   switch (type) {
     case 'number':
       // Create typed array of the given size if number.
       try {
         let buffer = new Uint8Array(subject > 0 ? Math.floor(subject) : 0);
         return buffer;
       } catch (e) {
         if (/size and count too large/.test(e.message) ||
             /invalid arguments/.test(e.message))
           throw new RangeError('Could not instantiate buffer: size of buffer may be too large');
         else
           throw new Error('Could not instantiate buffer');
       }
       break;
     case 'string':
       // If string encode it and use buffer for the returned Uint8Array
       // to create a local patched version that acts like node buffer.
       encoding = encoding || 'utf8';
       return new Uint8Array(new TextEncoder(encoding).encode(subject).buffer);
     case 'object':
       // This form of the constructor uses the form of
       // new Uint8Array(buffer, offset, length);
       // So we can instantiate a typed array within the constructor
       // to inherit the appropriate properties, where both the
       // `subject` and newly instantiated buffer share the same underlying
       // data structure.
       if (arguments.length === 3)
         return new Uint8Array(subject, encoding, arguments[2]);
       // If array or alike just make a copy with a local patched prototype.
       else
         return new Uint8Array(subject);
     default:
       throw new TypeError('must start with number, buffer, array or string');
   }
 }
 exports.Buffer = Buffer;
 // Tests if `value` is a Buffer.
 Buffer.isBuffer = value => value instanceof Buffer
 // Returns true if the encoding is a valid encoding argument & false otherwise
 Buffer.isEncoding = function (encoding) {
   if (!encoding) return false;
   try {
     new TextDecoder(encoding);
   } catch(e) {
     return false;
   }
   return true;
 }
 // Gives the actual byte length of a string. encoding defaults to 'utf8'.
 // This is not the same as String.prototype.length since that returns the
 // number of characters in a string.
 Buffer.byteLength = (value, encoding = 'utf8') =>
   new TextEncoder(encoding).encode(value).byteLength
 // Direct copy of the nodejs's buffer implementation:
 // https://github.com/joyent/node/blob/b255f4c10a80343f9ce1cee56d0288361429e214/lib/buffer.js#L146-L177
 Buffer.concat = function(list, length) {
   if (!Array.isArray(list))
     throw new TypeError('Usage: Buffer.concat(list[, length])');
   if (typeof length === 'undefined') {
     length = 0;
     for (var i = 0; i < list.length; i++)
       length += list[i].length;
   } else {
     length = ~~length;
   }
   if (length < 0)
     length = 0;
   if (list.length === 0)
     return new Buffer(0);
   else if (list.length === 1)
     return list[0];
   if (length < 0)
     throw new RangeError('length is not a positive number');
   var buffer = new Buffer(length);
   var pos = 0;
   for (var i = 0; i < list.length; i++) {
     var buf = list[i];
     buf.copy(buffer, pos);
     pos += buf.length;
   }
   return buffer;
 };
 // Node buffer is very much like Uint8Array although it has bunch of methods
 // that typically can be used in combination with `DataView` while preserving
 // access by index. Since in SDK each module has it's own set of bult-ins it
 // ok to patch ours to make it nodejs Buffer compatible.
 Buffer.prototype = Uint8Array.prototype;
 Object.defineProperties(Buffer.prototype, {
   parent: {
     get: function() { return parents.get(this, undefined); }
   },
   view: {
     get: function () {
       let view = views.get(this, undefined);
       if (view) return view;
       view = new DataView(this.buffer);
       views.set(this, view);
       return view;
     }
   },
   toString: {
     value: function(encoding, start, end) {
       encoding = !!encoding ? (encoding + '').toLowerCase() : 'utf8';
       start = Math.max(0, ~~start);
       end = Math.min(this.length, end === void(0) ? this.length : ~~end);
       return new TextDecoder(encoding).decode(this.subarray(start, end));
     }
   },
   toJSON: {
     value: function() {
       return { type: 'Buffer', data: Array.slice(this, 0) };
     }
   },
   get: {
     value: function(offset) {
       return this[offset];
     }
   },
   set: {
     value: function(offset, value) { this[offset] = value; }
   },
   copy: {
     value: function(target, offset, start, end) {
       let length = this.length;
       let targetLength = target.length;
       offset = isNumber(offset) ? offset : 0;
       start = isNumber(start) ? start : 0;
       if (start < 0)
         throw new RangeError('sourceStart is outside of valid range');
       if (end < 0)
         throw new RangeError('sourceEnd is outside of valid range');
       // If sourceStart > sourceEnd, or targetStart > targetLength,
       // zero bytes copied
       if (start > end ||
           offset > targetLength
           )
         return 0;
       // If `end` is not defined, or if it is defined
       // but would overflow `target`, redefine `end`
       // so we can copy as much as we can
       if (end - start > targetLength - offset ||
           end == null) {
         let remainingTarget = targetLength - offset;
         let remainingSource = length - start;
         if (remainingSource <= remainingTarget)
           end = length;
         else
           end = start + remainingTarget;
       }
       Uint8Array.set(target, this.subarray(start, end), offset);
       return end - start;
     }
   },
   slice: {
     value: function(start, end) {
       let length = this.length;
       start = ~~start;
       end = end != null ? end : length;
       if (start < 0) {
         start += length;
         if (start < 0) start = 0;
       } else if (start > length)
         start = length;
       if (end < 0) {
         end += length;
         if (end < 0) end = 0;
       } else if (end > length)
         end = length;
       if (end < start)
         end = start;
       // This instantiation uses the new Uint8Array(buffer, offset, length) version
       // of construction to share the same underling data structure
       let buffer = new Buffer(this.buffer, start, end - start);
       // If buffer has a value, assign its parent value to the
       // buffer it shares its underlying structure with. If a slice of
       // a slice, then use the root structure
       if (buffer.length > 0)
         parents.set(buffer, this.parent || this);
       return buffer;
     }
   },
   write: {
     value: function(string, offset, length, encoding = 'utf8') {
       // write(string, encoding);
       if (typeof(offset) === 'string' && Number.isNaN(parseInt(offset))) {
         ([offset, length, encoding]) = [0, null, offset];
       }
       // write(string, offset, encoding);
       else if (typeof(length) === 'string')
         ([length, encoding]) = [null, length];
       if (offset < 0 || offset > this.length)
         throw new RangeError('offset is outside of valid range');
       offset = ~~offset;
       // Clamp length if it would overflow buffer, or if its
       // undefined
       if (length == null || length + offset > this.length)
         length = this.length - offset;
       let buffer = new TextEncoder(encoding).encode(string);
       let result = Math.min(buffer.length, length);
       if (buffer.length !== length)
         buffer = buffer.subarray(0, length);
       Uint8Array.set(this, buffer, offset);
       return result;
     }
   },
   fill: {
     value: function fill(value, start, end) {
       let length = this.length;
       value = value || 0;
       start = start || 0;
       end = end || length;
       if (typeof(value) === 'string')
         value = value.charCodeAt(0);
       if (typeof(value) !== 'number' || isNaN(value))
         throw TypeError('value is not a number');
       if (end < start)
         throw new RangeError('end < start');
       // Fill 0 bytes; we're done
       if (end === start)
         return 0;
       if (length == 0)
         return 0;
       if (start < 0 || start >= length)
         throw RangeError('start out of bounds');
       if (end < 0 || end > length)
         throw RangeError('end out of bounds');
       let index = start;
       while (index < end) this[index++] = value;
     }
   }
 });
 // Define nodejs Buffer's getter and setter functions that just proxy
 // to internal DataView's equivalent methods.
 // TODO do we need to check architecture to see if it's default big/little endian?
 [['readUInt16LE', 'getUint16', true],
  ['readUInt16BE', 'getUint16', false],
  ['readInt16LE', 'getInt16', true],
  ['readInt16BE', 'getInt16', false],
  ['readUInt32LE', 'getUint32', true],
  ['readUInt32BE', 'getUint32', false],
  ['readInt32LE', 'getInt32', true],
  ['readInt32BE', 'getInt32', false],
  ['readFloatLE', 'getFloat32', true],
  ['readFloatBE', 'getFloat32', false],
  ['readDoubleLE', 'getFloat64', true],
  ['readDoubleBE', 'getFloat64', false],
  ['readUInt8', 'getUint8'],
  ['readInt8', 'getInt8']].forEach(([alias, name, littleEndian]) => {
   Object.defineProperty(Buffer.prototype, alias, {
     value: function(offset) this.view[name](offset, littleEndian)
   });
 });
 [['writeUInt16LE', 'setUint16', true],
  ['writeUInt16BE', 'setUint16', false],
  ['writeInt16LE', 'setInt16', true],
  ['writeInt16BE', 'setInt16', false],
  ['writeUInt32LE', 'setUint32', true],
  ['writeUInt32BE', 'setUint32', false],
  ['writeInt32LE', 'setInt32', true],
  ['writeInt32BE', 'setInt32', false],
  ['writeFloatLE', 'setFloat32', true],
  ['writeFloatBE', 'setFloat32', false],
  ['writeDoubleLE', 'setFloat64', true],
  ['writeDoubleBE', 'setFloat64', false],
  ['writeUInt8', 'setUint8'],
  ['writeInt8', 'setInt8']].forEach(([alias, name, littleEndian]) => {
   Object.defineProperty(Buffer.prototype, alias, {
     value: function(value, offset) this.view[name](offset, value, littleEndian)
   });
 });