swh:1:snp:c53ab93da1867a0ee99951a3636bca865f9194df
Tip revision: 56f80625399de02abfe6c0d718ea5a8939969318 authored by Luigi Pinca on 04 November 2017, 09:20:38 UTC
[dist] 3.3.0
[dist] 3.3.0
Tip revision: 56f8062
Sender.js
/*!
* ws: a node.js websocket client
* Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
* MIT Licensed
*/
'use strict';
const safeBuffer = require('safe-buffer');
const crypto = require('crypto');
const PerMessageDeflate = require('./PerMessageDeflate');
const bufferUtil = require('./BufferUtil');
const ErrorCodes = require('./ErrorCodes');
const Buffer = safeBuffer.Buffer;
/**
* HyBi Sender implementation.
*/
class Sender {
/**
* Creates a Sender instance.
*
* @param {net.Socket} socket The connection socket
* @param {Object} extensions An object containing the negotiated extensions
*/
constructor (socket, extensions) {
this._extensions = extensions || {};
this._socket = socket;
this._firstFragment = true;
this._compress = false;
this._bufferedBytes = 0;
this._deflating = false;
this._queue = [];
}
/**
* Frames a piece of data according to the HyBi WebSocket protocol.
*
* @param {Buffer} data The data to frame
* @param {Object} options Options object
* @param {Number} options.opcode The opcode
* @param {Boolean} options.readOnly Specifies whether `data` can be modified
* @param {Boolean} options.fin Specifies whether or not to set the FIN bit
* @param {Boolean} options.mask Specifies whether or not to mask `data`
* @param {Boolean} options.rsv1 Specifies whether or not to set the RSV1 bit
* @return {Buffer[]} The framed data as a list of `Buffer` instances
* @public
*/
static frame (data, options) {
const merge = data.length < 1024 || (options.mask && options.readOnly);
var offset = options.mask ? 6 : 2;
var payloadLength = data.length;
if (data.length >= 65536) {
offset += 8;
payloadLength = 127;
} else if (data.length > 125) {
offset += 2;
payloadLength = 126;
}
const target = Buffer.allocUnsafe(merge ? data.length + offset : offset);
target[0] = options.fin ? options.opcode | 0x80 : options.opcode;
if (options.rsv1) target[0] |= 0x40;
if (payloadLength === 126) {
target.writeUInt16BE(data.length, 2, true);
} else if (payloadLength === 127) {
target.writeUInt32BE(0, 2, true);
target.writeUInt32BE(data.length, 6, true);
}
if (!options.mask) {
target[1] = payloadLength;
if (merge) {
data.copy(target, offset);
return [target];
}
return [target, data];
}
const mask = crypto.randomBytes(4);
target[1] = payloadLength | 0x80;
target[offset - 4] = mask[0];
target[offset - 3] = mask[1];
target[offset - 2] = mask[2];
target[offset - 1] = mask[3];
if (merge) {
bufferUtil.mask(data, mask, target, offset, data.length);
return [target];
}
bufferUtil.mask(data, mask, data, 0, data.length);
return [target, data];
}
/**
* Sends a close message to the other peer.
*
* @param {(Number|undefined)} code The status code component of the body
* @param {String} data The message component of the body
* @param {Boolean} mask Specifies whether or not to mask the message
* @param {Function} cb Callback
* @public
*/
close (code, data, mask, cb) {
if (code !== undefined && (typeof code !== 'number' || !ErrorCodes.isValidErrorCode(code))) {
throw new Error('first argument must be a valid error code number');
}
const buf = Buffer.allocUnsafe(2 + (data ? Buffer.byteLength(data) : 0));
buf.writeUInt16BE(code || 1000, 0, true);
if (buf.length > 2) buf.write(data, 2);
if (this._deflating) {
this.enqueue([this.doClose, buf, mask, cb]);
} else {
this.doClose(buf, mask, cb);
}
}
/**
* Frames and sends a close message.
*
* @param {Buffer} data The message to send
* @param {Boolean} mask Specifies whether or not to mask `data`
* @param {Function} cb Callback
* @private
*/
doClose (data, mask, cb) {
this.sendFrame(Sender.frame(data, {
fin: true,
rsv1: false,
opcode: 0x08,
mask,
readOnly: false
}), cb);
}
/**
* Sends a ping message to the other peer.
*
* @param {*} data The message to send
* @param {Boolean} mask Specifies whether or not to mask `data`
* @public
*/
ping (data, mask) {
var readOnly = true;
if (!Buffer.isBuffer(data)) {
if (data instanceof ArrayBuffer) {
data = Buffer.from(data);
} else if (ArrayBuffer.isView(data)) {
data = viewToBuffer(data);
} else {
data = Buffer.from(data);
readOnly = false;
}
}
if (this._deflating) {
this.enqueue([this.doPing, data, mask, readOnly]);
} else {
this.doPing(data, mask, readOnly);
}
}
/**
* Frames and sends a ping message.
*
* @param {*} data The message to send
* @param {Boolean} mask Specifies whether or not to mask `data`
* @param {Boolean} readOnly Specifies whether `data` can be modified
* @private
*/
doPing (data, mask, readOnly) {
this.sendFrame(Sender.frame(data, {
fin: true,
rsv1: false,
opcode: 0x09,
mask,
readOnly
}));
}
/**
* Sends a pong message to the other peer.
*
* @param {*} data The message to send
* @param {Boolean} mask Specifies whether or not to mask `data`
* @public
*/
pong (data, mask) {
var readOnly = true;
if (!Buffer.isBuffer(data)) {
if (data instanceof ArrayBuffer) {
data = Buffer.from(data);
} else if (ArrayBuffer.isView(data)) {
data = viewToBuffer(data);
} else {
data = Buffer.from(data);
readOnly = false;
}
}
if (this._deflating) {
this.enqueue([this.doPong, data, mask, readOnly]);
} else {
this.doPong(data, mask, readOnly);
}
}
/**
* Frames and sends a pong message.
*
* @param {*} data The message to send
* @param {Boolean} mask Specifies whether or not to mask `data`
* @param {Boolean} readOnly Specifies whether `data` can be modified
* @private
*/
doPong (data, mask, readOnly) {
this.sendFrame(Sender.frame(data, {
fin: true,
rsv1: false,
opcode: 0x0a,
mask,
readOnly
}));
}
/**
* Sends a data message to the other peer.
*
* @param {*} data The message to send
* @param {Object} options Options object
* @param {Boolean} options.compress Specifies whether or not to compress `data`
* @param {Boolean} options.binary Specifies whether `data` is binary or text
* @param {Boolean} options.fin Specifies whether the fragment is the last one
* @param {Boolean} options.mask Specifies whether or not to mask `data`
* @param {Function} cb Callback
* @public
*/
send (data, options, cb) {
var opcode = options.binary ? 2 : 1;
var rsv1 = options.compress;
var readOnly = true;
if (!Buffer.isBuffer(data)) {
if (data instanceof ArrayBuffer) {
data = Buffer.from(data);
} else if (ArrayBuffer.isView(data)) {
data = viewToBuffer(data);
} else {
data = Buffer.from(data);
readOnly = false;
}
}
const perMessageDeflate = this._extensions[PerMessageDeflate.extensionName];
if (this._firstFragment) {
this._firstFragment = false;
if (rsv1 && perMessageDeflate) {
rsv1 = data.length >= perMessageDeflate._threshold;
}
this._compress = rsv1;
} else {
rsv1 = false;
opcode = 0;
}
if (options.fin) this._firstFragment = true;
if (perMessageDeflate) {
const opts = {
fin: options.fin,
rsv1,
opcode,
mask: options.mask,
readOnly
};
if (this._deflating) {
this.enqueue([this.dispatch, data, this._compress, opts, cb]);
} else {
this.dispatch(data, this._compress, opts, cb);
}
} else {
this.sendFrame(Sender.frame(data, {
fin: options.fin,
rsv1: false,
opcode,
mask: options.mask,
readOnly
}), cb);
}
}
/**
* Dispatches a data message.
*
* @param {Buffer} data The message to send
* @param {Boolean} compress Specifies whether or not to compress `data`
* @param {Object} options Options object
* @param {Number} options.opcode The opcode
* @param {Boolean} options.readOnly Specifies whether `data` can be modified
* @param {Boolean} options.fin Specifies whether or not to set the FIN bit
* @param {Boolean} options.mask Specifies whether or not to mask `data`
* @param {Boolean} options.rsv1 Specifies whether or not to set the RSV1 bit
* @param {Function} cb Callback
* @private
*/
dispatch (data, compress, options, cb) {
if (!compress) {
this.sendFrame(Sender.frame(data, options), cb);
return;
}
const perMessageDeflate = this._extensions[PerMessageDeflate.extensionName];
this._deflating = true;
perMessageDeflate.compress(data, options.fin, (_, buf) => {
options.readOnly = false;
this.sendFrame(Sender.frame(buf, options), cb);
this._deflating = false;
this.dequeue();
});
}
/**
* Executes queued send operations.
*
* @private
*/
dequeue () {
while (!this._deflating && this._queue.length) {
const params = this._queue.shift();
this._bufferedBytes -= params[1].length;
params[0].apply(this, params.slice(1));
}
}
/**
* Enqueues a send operation.
*
* @param {Array} params Send operation parameters.
* @private
*/
enqueue (params) {
this._bufferedBytes += params[1].length;
this._queue.push(params);
}
/**
* Sends a frame.
*
* @param {Buffer[]} list The frame to send
* @param {Function} cb Callback
* @private
*/
sendFrame (list, cb) {
if (list.length === 2) {
this._socket.write(list[0]);
this._socket.write(list[1], cb);
} else {
this._socket.write(list[0], cb);
}
}
}
module.exports = Sender;
/**
* Converts an `ArrayBuffer` view into a buffer.
*
* @param {(DataView|TypedArray)} view The view to convert
* @return {Buffer} Converted view
* @private
*/
function viewToBuffer (view) {
const buf = Buffer.from(view.buffer);
if (view.byteLength !== view.buffer.byteLength) {
return buf.slice(view.byteOffset, view.byteOffset + view.byteLength);
}
return buf;
}