132 lines
3.0 KiB
JavaScript
132 lines
3.0 KiB
JavaScript
'use strict';
|
|
|
|
const { EMPTY_BUFFER } = require('./constants');
|
|
|
|
const FastBuffer = Buffer[Symbol.species];
|
|
|
|
/**
|
|
* 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 new FastBuffer(target.buffer, target.byteOffset, 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.length === buf.buffer.byteLength) {
|
|
return buf.buffer;
|
|
}
|
|
|
|
return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.length);
|
|
}
|
|
|
|
/**
|
|
* 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 = new FastBuffer(data);
|
|
} else if (ArrayBuffer.isView(data)) {
|
|
buf = new FastBuffer(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.
|
|
}
|
|
}
|