morphit/node_modules/cborg/lib/byte-utils.js

320 lines
8.4 KiB
JavaScript

// Use Uint8Array directly in the browser, use Buffer in Node.js but don't
// speak its name directly to avoid bundlers pulling in the `Buffer` polyfill
// @ts-ignore
export const useBuffer = globalThis.process &&
// @ts-ignore
!globalThis.process.browser &&
// @ts-ignore
globalThis.Buffer &&
// @ts-ignore
typeof globalThis.Buffer.isBuffer === 'function'
const textEncoder = new TextEncoder()
/**
* @param {Uint8Array} buf
* @returns {boolean}
*/
function isBuffer (buf) {
// @ts-ignore
return useBuffer && globalThis.Buffer.isBuffer(buf)
}
/**
* @param {Uint8Array|number[]} buf
* @returns {Uint8Array}
*/
export function asU8A (buf) {
/* c8 ignore next */
if (!(buf instanceof Uint8Array)) {
return Uint8Array.from(buf)
}
return isBuffer(buf) ? new Uint8Array(buf.buffer, buf.byteOffset, buf.byteLength) : buf
}
// Threshold for manual UTF-8 encoding vs native methods.
// Node.js Buffer.from: crossover ~24 chars
// Browser TextEncoder: crossover ~200 chars
const FROM_STRING_THRESHOLD_BUFFER = 24
const FROM_STRING_THRESHOLD_TEXTENCODER = 200
export const fromString = useBuffer
? // eslint-disable-line operator-linebreak
/**
* @param {string} string
*/
(string) => {
return string.length >= FROM_STRING_THRESHOLD_BUFFER
? // eslint-disable-line operator-linebreak
// @ts-ignore
globalThis.Buffer.from(string)
: utf8ToBytes(string)
}
/* c8 ignore next 7 */
: // eslint-disable-line operator-linebreak
/**
* @param {string} string
*/
(string) => {
return string.length >= FROM_STRING_THRESHOLD_TEXTENCODER ? textEncoder.encode(string) : utf8ToBytes(string)
}
/**
* Buffer variant not fast enough for what we need
* @param {number[]} arr
* @returns {Uint8Array}
*/
export const fromArray = (arr) => {
return Uint8Array.from(arr)
}
export const slice = useBuffer
? // eslint-disable-line operator-linebreak
/**
* @param {Uint8Array} bytes
* @param {number} start
* @param {number} end
*/
// Buffer.slice() returns a view, not a copy, so we need special handling
(bytes, start, end) => {
if (isBuffer(bytes)) {
return new Uint8Array(bytes.subarray(start, end))
}
return bytes.slice(start, end)
}
/* c8 ignore next 9 */
: // eslint-disable-line operator-linebreak
/**
* @param {Uint8Array} bytes
* @param {number} start
* @param {number} end
*/
(bytes, start, end) => {
return bytes.slice(start, end)
}
export const concat = useBuffer
? // eslint-disable-line operator-linebreak
/**
* @param {Uint8Array[]} chunks
* @param {number} length
* @returns {Uint8Array}
*/
(chunks, length) => {
// might get a stray plain Array here
/* c8 ignore next 1 */
chunks = chunks.map((c) => c instanceof Uint8Array
? c
// this case is occasionally missed during test runs so becomes coverage-flaky
/* c8 ignore next 4 */
: // eslint-disable-line operator-linebreak
// @ts-ignore
globalThis.Buffer.from(c))
// @ts-ignore
return asU8A(globalThis.Buffer.concat(chunks, length))
}
/* c8 ignore next 19 */
: // eslint-disable-line operator-linebreak
/**
* @param {Uint8Array[]} chunks
* @param {number} length
* @returns {Uint8Array}
*/
(chunks, length) => {
const out = new Uint8Array(length)
let off = 0
for (let b of chunks) {
if (off + b.length > out.length) {
// final chunk that's bigger than we need
b = b.subarray(0, out.length - off)
}
out.set(b, off)
off += b.length
}
return out
}
export const alloc = useBuffer
? // eslint-disable-line operator-linebreak
/**
* @param {number} size
* @returns {Uint8Array}
*/
(size) => {
// we always write over the contents we expose so this should be safe
// @ts-ignore
return globalThis.Buffer.allocUnsafe(size)
}
/* c8 ignore next 8 */
: // eslint-disable-line operator-linebreak
/**
* @param {number} size
* @returns {Uint8Array}
*/
(size) => {
return new Uint8Array(size)
}
export const toHex = useBuffer
? // eslint-disable-line operator-linebreak
/**
* @param {Uint8Array} d
* @returns {string}
*/
(d) => {
if (typeof d === 'string') {
return d
}
// @ts-ignore
return globalThis.Buffer.from(toBytes(d)).toString('hex')
}
/* c8 ignore next 12 */
: // eslint-disable-line operator-linebreak
/**
* @param {Uint8Array} d
* @returns {string}
*/
(d) => {
if (typeof d === 'string') {
return d
}
// @ts-ignore not smart enough to figure this out
return Array.prototype.reduce.call(toBytes(d), (p, c) => `${p}${c.toString(16).padStart(2, '0')}`, '')
}
export const fromHex = useBuffer
? // eslint-disable-line operator-linebreak
/**
* @param {string|Uint8Array} hex
* @returns {Uint8Array}
*/
(hex) => {
if (hex instanceof Uint8Array) {
return hex
}
// @ts-ignore
return globalThis.Buffer.from(hex, 'hex')
}
/* c8 ignore next 17 */
: // eslint-disable-line operator-linebreak
/**
* @param {string|Uint8Array} hex
* @returns {Uint8Array}
*/
(hex) => {
if (hex instanceof Uint8Array) {
return hex
}
if (!hex.length) {
return new Uint8Array(0)
}
return new Uint8Array(hex.split('')
.map((/** @type {string} */ c, /** @type {number} */ i, /** @type {string[]} */ d) => i % 2 === 0 ? `0x${c}${d[i + 1]}` : '')
.filter(Boolean)
.map((/** @type {string} */ e) => parseInt(e, 16)))
}
/**
* @param {Uint8Array|ArrayBuffer|ArrayBufferView} obj
* @returns {Uint8Array}
*/
function toBytes (obj) {
if (obj instanceof Uint8Array && obj.constructor.name === 'Uint8Array') {
return obj
}
if (obj instanceof ArrayBuffer) {
return new Uint8Array(obj)
}
if (ArrayBuffer.isView(obj)) {
return new Uint8Array(obj.buffer, obj.byteOffset, obj.byteLength)
}
/* c8 ignore next */
throw new Error('Unknown type, must be binary type')
}
/**
* @param {Uint8Array} b1
* @param {Uint8Array} b2
* @returns {number}
*/
export function compare (b1, b2) {
/* c8 ignore next 5 */
if (isBuffer(b1) && isBuffer(b2)) {
// probably not possible to get here in the current API
// @ts-ignore Buffer
return b1.compare(b2)
}
for (let i = 0; i < b1.length; i++) {
if (b1[i] === b2[i]) {
continue
}
return b1[i] < b2[i] ? -1 : 1
} /* c8 ignore next 3 */
return 0
}
// The below code is taken from https://github.com/google/closure-library/blob/8598d87242af59aac233270742c8984e2b2bdbe0/closure/goog/crypt/crypt.js#L117-L143
// Licensed Apache-2.0.
/**
* @param {string} str
* @returns {number[]}
*/
function utf8ToBytes (str) {
const out = []
let p = 0
for (let i = 0; i < str.length; i++) {
let c = str.charCodeAt(i)
if (c < 128) {
out[p++] = c
} else if (c < 2048) {
out[p++] = (c >> 6) | 192
out[p++] = (c & 63) | 128
} else if (
((c & 0xFC00) === 0xD800) && (i + 1) < str.length &&
((str.charCodeAt(i + 1) & 0xFC00) === 0xDC00)) {
// Surrogate Pair
c = 0x10000 + ((c & 0x03FF) << 10) + (str.charCodeAt(++i) & 0x03FF)
out[p++] = (c >> 18) | 240
out[p++] = ((c >> 12) & 63) | 128
out[p++] = ((c >> 6) & 63) | 128
out[p++] = (c & 63) | 128
} else {
if ((c >= 0xD800) && (c <= 0xDFFF)) {
c = 0xFFFD // Unpaired Surrogate
}
out[p++] = (c >> 12) | 224
out[p++] = ((c >> 6) & 63) | 128
out[p++] = (c & 63) | 128
}
}
return out
}
// Based on http://stackoverflow.com/a/22747272/680742, the browser with
// the lowest limit is Chrome, with 0x10000 args.
// We go 1 magnitude less, for safety
const MAX_ARGUMENTS_LENGTH = 0x1000
/**
* @param {number[]} codePoints
* @returns {string}
*/
export function decodeCodePointsArray (codePoints) {
const len = codePoints.length
if (len <= MAX_ARGUMENTS_LENGTH) {
return String.fromCharCode.apply(String, codePoints) // avoid extra slice()
}
/* c8 ignore next 10 */
// Decode in chunks to avoid "call stack size exceeded".
let res = ''
let i = 0
while (i < len) {
res += String.fromCharCode.apply(
String,
codePoints.slice(i, i += MAX_ARGUMENTS_LENGTH)
)
}
return res
}