implemented frontend including separate message system; started to implement backend

yjs-poll/node_modules/lib0/buffer.js

@@ -0,0 +1,163 @@
+/**
+ * Utility functions to work with buffers (Uint8Array).
+ *
+ * @module buffer
+ */
+
+import * as string from './string.js'
+import * as env from './environment.js'
+import * as array from './array.js'
+import * as math from './math.js'
+import * as encoding from './encoding.js'
+import * as decoding from './decoding.js'
+
+/**
+ * @param {number} len
+ */
+export const createUint8ArrayFromLen = len => new Uint8Array(len)
+
+/**
+ * Create Uint8Array with initial content from buffer
+ *
+ * @param {ArrayBuffer} buffer
+ * @param {number} byteOffset
+ * @param {number} length
+ */
+export const createUint8ArrayViewFromArrayBuffer = (buffer, byteOffset, length) => new Uint8Array(buffer, byteOffset, length)
+
+/**
+ * Create Uint8Array with initial content from buffer
+ *
+ * @param {ArrayBuffer} buffer
+ */
+export const createUint8ArrayFromArrayBuffer = buffer => new Uint8Array(buffer)
+
+/* c8 ignore start */
+/**
+ * @param {Uint8Array} bytes
+ * @return {string}
+ */
+const toBase64Browser = bytes => {
+  let s = ''
+  for (let i = 0; i < bytes.byteLength; i++) {
+    s += string.fromCharCode(bytes[i])
+  }
+  // eslint-disable-next-line no-undef
+  return btoa(s)
+}
+/* c8 ignore stop */
+
+/**
+ * @param {Uint8Array} bytes
+ * @return {string}
+ */
+const toBase64Node = bytes => Buffer.from(bytes.buffer, bytes.byteOffset, bytes.byteLength).toString('base64')
+
+/* c8 ignore start */
+/**
+ * @param {string} s
+ * @return {Uint8Array<ArrayBuffer>}
+ */
+const fromBase64Browser = s => {
+  // eslint-disable-next-line no-undef
+  const a = atob(s)
+  const bytes = createUint8ArrayFromLen(a.length)
+  for (let i = 0; i < a.length; i++) {
+    bytes[i] = a.charCodeAt(i)
+  }
+  return bytes
+}
+/* c8 ignore stop */
+
+/**
+ * @param {string} s
+ */
+const fromBase64Node = s => {
+  const buf = Buffer.from(s, 'base64')
+  return createUint8ArrayViewFromArrayBuffer(buf.buffer, buf.byteOffset, buf.byteLength)
+}
+
+/* c8 ignore next */
+export const toBase64 = env.isBrowser ? toBase64Browser : toBase64Node
+
+/* c8 ignore next */
+export const fromBase64 = env.isBrowser ? fromBase64Browser : fromBase64Node
+
+/**
+ * Implements base64url - see https://datatracker.ietf.org/doc/html/rfc4648#section-5
+ * @param {Uint8Array} buf
+ */
+export const toBase64UrlEncoded = buf => toBase64(buf).replaceAll('+', '-').replaceAll('/', '_').replaceAll('=', '')
+
+/**
+ * @param {string} base64
+ */
+export const fromBase64UrlEncoded = base64 => fromBase64(base64.replaceAll('-', '+').replaceAll('_', '/'))
+
+/**
+ * Base64 is always a more efficient choice. This exists for utility purposes only.
+ *
+ * @param {Uint8Array} buf
+ */
+export const toHexString = buf => array.map(buf, b => b.toString(16).padStart(2, '0')).join('')
+
+/**
+ * Note: This function expects that the hex doesn't start with 0x..
+ *
+ * @param {string} hex
+ */
+export const fromHexString = hex => {
+  const hlen = hex.length
+  const buf = new Uint8Array(math.ceil(hlen / 2))
+  for (let i = 0; i < hlen; i += 2) {
+    buf[buf.length - i / 2 - 1] = Number.parseInt(hex.slice(hlen - i - 2, hlen - i), 16)
+  }
+  return buf
+}
+
+/**
+ * Copy the content of an Uint8Array view to a new ArrayBuffer.
+ *
+ * @param {Uint8Array} uint8Array
+ * @return {Uint8Array}
+ */
+export const copyUint8Array = uint8Array => {
+  const newBuf = createUint8ArrayFromLen(uint8Array.byteLength)
+  newBuf.set(uint8Array)
+  return newBuf
+}
+
+/**
+ * Encode anything as a UInt8Array. It's a pun on typescripts's `any` type.
+ * See encoding.writeAny for more information.
+ *
+ * @param {any} data
+ * @return {Uint8Array}
+ */
+export const encodeAny = data =>
+  encoding.encode(encoder => encoding.writeAny(encoder, data))
+
+/**
+ * Decode an any-encoded value.
+ *
+ * @param {Uint8Array} buf
+ * @return {any}
+ */
+export const decodeAny = buf => decoding.readAny(decoding.createDecoder(buf))
+
+/**
+ * Shift Byte Array {N} bits to the left. Does not expand byte array.
+ *
+ * @param {Uint8Array} bs
+ * @param {number} N should be in the range of [0-7]
+ */
+export const shiftNBitsLeft = (bs, N) => {
+  if (N === 0) return bs
+  bs = new Uint8Array(bs)
+  bs[0] <<= N
+  for (let i = 1; i < bs.length; i++) {
+    bs[i - 1] |= bs[i] >>> (8 - N)
+    bs[i] <<= N
+  }
+  return bs
+}