source: trip-planner-front/node_modules/ws/lib/buffer-util.js@ 6a80231

Last change on this file since 6a80231 was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

initial commit

  • Property mode set to 100644
File size: 3.0 KB
Line 
1'use strict';
2
3const { EMPTY_BUFFER } = require('./constants');
4
5/**
6 * Merges an array of buffers into a new buffer.
7 *
8 * @param {Buffer[]} list The array of buffers to concat
9 * @param {Number} totalLength The total length of buffers in the list
10 * @return {Buffer} The resulting buffer
11 * @public
12 */
13function concat(list, totalLength) {
14 if (list.length === 0) return EMPTY_BUFFER;
15 if (list.length === 1) return list[0];
16
17 const target = Buffer.allocUnsafe(totalLength);
18 let offset = 0;
19
20 for (let i = 0; i < list.length; i++) {
21 const buf = list[i];
22 target.set(buf, offset);
23 offset += buf.length;
24 }
25
26 if (offset < totalLength) return target.slice(0, offset);
27
28 return target;
29}
30
31/**
32 * Masks a buffer using the given mask.
33 *
34 * @param {Buffer} source The buffer to mask
35 * @param {Buffer} mask The mask to use
36 * @param {Buffer} output The buffer where to store the result
37 * @param {Number} offset The offset at which to start writing
38 * @param {Number} length The number of bytes to mask.
39 * @public
40 */
41function _mask(source, mask, output, offset, length) {
42 for (let i = 0; i < length; i++) {
43 output[offset + i] = source[i] ^ mask[i & 3];
44 }
45}
46
47/**
48 * Unmasks a buffer using the given mask.
49 *
50 * @param {Buffer} buffer The buffer to unmask
51 * @param {Buffer} mask The mask to use
52 * @public
53 */
54function _unmask(buffer, mask) {
55 // Required until https://github.com/nodejs/node/issues/9006 is resolved.
56 const length = buffer.length;
57 for (let i = 0; i < length; i++) {
58 buffer[i] ^= mask[i & 3];
59 }
60}
61
62/**
63 * Converts a buffer to an `ArrayBuffer`.
64 *
65 * @param {Buffer} buf The buffer to convert
66 * @return {ArrayBuffer} Converted buffer
67 * @public
68 */
69function toArrayBuffer(buf) {
70 if (buf.byteLength === buf.buffer.byteLength) {
71 return buf.buffer;
72 }
73
74 return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
75}
76
77/**
78 * Converts `data` to a `Buffer`.
79 *
80 * @param {*} data The data to convert
81 * @return {Buffer} The buffer
82 * @throws {TypeError}
83 * @public
84 */
85function toBuffer(data) {
86 toBuffer.readOnly = true;
87
88 if (Buffer.isBuffer(data)) return data;
89
90 let buf;
91
92 if (data instanceof ArrayBuffer) {
93 buf = Buffer.from(data);
94 } else if (ArrayBuffer.isView(data)) {
95 buf = Buffer.from(data.buffer, data.byteOffset, data.byteLength);
96 } else {
97 buf = Buffer.from(data);
98 toBuffer.readOnly = false;
99 }
100
101 return buf;
102}
103
104try {
105 const bufferUtil = require('bufferutil');
106 const bu = bufferUtil.BufferUtil || bufferUtil;
107
108 module.exports = {
109 concat,
110 mask(source, mask, output, offset, length) {
111 if (length < 48) _mask(source, mask, output, offset, length);
112 else bu.mask(source, mask, output, offset, length);
113 },
114 toArrayBuffer,
115 toBuffer,
116 unmask(buffer, mask) {
117 if (buffer.length < 32) _unmask(buffer, mask);
118 else bu.unmask(buffer, mask);
119 }
120 };
121} catch (e) /* istanbul ignore next */ {
122 module.exports = {
123 concat,
124 mask: _mask,
125 toArrayBuffer,
126 toBuffer,
127 unmask: _unmask
128 };
129}
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