Implement smart buffer

package.json

@@ -18,8 +18,11 @@
     "@types/jest": "^27.4.0",
     "jest": "^27.4.7",
     "ts-jest": "^27.1.3",
+    "ts-loader": "^9.2.6",
     "ts-standard": "^11.0.0",
-    "typescript": "^4.5.5"
+    "typescript": "^4.5.5",
+    "webpack": "^5.68.0",
+    "webpack-cli": "^4.9.2"
   },
   "jest": {
     "verbose": true,

src/bennc.ts

@@ -1,17 +1,23 @@
 import { IMessageEvent } from 'websocket'
 import { IncomingPacket } from './structures/server'
+// import { SubscribeMessage } from './structures/subscribe'
 
 export function connect (url: string): void {
   const webSocket = new WebSocket(url)
   webSocket.binaryType = 'arraybuffer'
-  webSocket.onopen = onOpen
   webSocket.onmessage = onMessage
-}
 
-function onOpen (): void {
-  console.log('Connected!')
+  webSocket.onopen = () => {
+    console.log('Connected!')
+    // const subscribeMessage = new SubscribeMessage(0x0001)
+    const tmp = Uint8Array.from([0x00, 0x00, 0x00, 0x02, 0x00, 0x01])
+    console.log(tmp)
+    webSocket.send(tmp)
+  }
 }
 
 function onMessage (event: IMessageEvent): void {
-  console.log(new IncomingPacket(event.data as Buffer))
+  console.log('New message.')
+  console.log(event.data)
+  console.log(new IncomingPacket(event.data as ArrayBuffer))
 }

src/buffer-reader.ts

@@ -1,37 +0,0 @@
-import { ByteLength } from './common'
-
-export class BufferReader {
-  private readonly _data: Buffer
-  private _cursor: number
-
-  constructor (data: Buffer = Buffer.from([])) {
-    this._data = data
-    this._cursor = 0
-  }
-
-  get cursor (): number {
-    return this._cursor
-  }
-
-  set cursor (position: number) {
-    if (position < 0 || position > this._data.length) {
-      throw RangeError(`Cannot seek to ${this.cursor} of ${this._data.length} bytes.`)
-    }
-    this._cursor = position
-  }
-
-  readUInt16 (): number {
-    this.cursor += ByteLength.UInt16
-    return this._data.slice(this.cursor - ByteLength.UInt16, this.cursor).readInt16BE()
-  }
-
-  readUInt32 (): number {
-    this.cursor += ByteLength.UInt32
-    return this._data.slice(this.cursor - ByteLength.UInt32, this.cursor).readInt32BE()
-  }
-
-  readBuffer (len: number): Buffer {
-    this.cursor += len
-    return this._data.slice(this.cursor - len, this.cursor)
-  }
-}

src/common.ts

@@ -1,3 +1,5 @@
+export const MAX_DATA_LENGTH = 1000
+
 export enum ByteLength {
   UInt16 = 2,
   UInt32 = 4

src/index.ts

@@ -1 +1,3 @@
-export { connect } from './bennc'
+import { connect } from './bennc'
+
+connect('wss://chat.3t.network/BENNC')

src/smart-buffer.ts

@@ -0,0 +1,158 @@
+import { ByteLength } from './common'
+
+export class SmartBuffer {
+  private _data: number[]
+  private _cursor: number
+
+  /**
+  * Wrap a buffer to track position and provide useful read / write functionality.
+  * @param data Buffer to wrap (optional).
+  */
+  constructor (data?: Uint8Array) {
+    this._data = data === undefined ? [] : [...data]
+    this._cursor = 0
+  }
+
+  /**
+  * Return a regular buffer.
+  */
+  get data (): Uint8Array {
+    return Uint8Array.from(this._data)
+  }
+
+  /**
+  * Update the smart buffer to wrap new data.
+  */
+  set data (data: Uint8Array) {
+    this._data = [...data]
+    this.cursor = 0
+  }
+
+  /**
+  * Get the length of the smart buffer data.
+  */
+  get length (): number {
+    return this._data.length
+  }
+
+  /**
+  * Set the length of the smart buffer data.
+  */
+  set length (length: number) {
+    this._data.length = length
+  }
+
+  /**
+  * Get the current cursor position of the smart buffer.
+  */
+  get cursor (): number {
+    return this._cursor
+  }
+
+  /**
+  * Set the cursor position of the smart buffer.
+  */
+  set cursor (position: number) {
+    if (position < 0) {
+      throw RangeError(`Cannot seek to ${this.cursor} of ${this.length} bytes.`)
+    }
+    this._cursor = position
+  }
+
+  /**
+  * Pads bytes to the end of the smart buffer.
+  * @param length The number of bytes to pad.
+  */
+  pad (length: number): void {
+    this._data.push(...new Uint8Array(length))
+  }
+
+  /**
+  * Return the data from the specified range.
+  * @param start The start position.
+  * @param end The end position.
+  * @returns A new buffer containing data from the specified range.
+  */
+  slice (start: number, end: number): Uint8Array {
+    return Uint8Array.from(this._data.slice(start, end))
+  }
+
+  /**
+   * Splice bytes into the smart buffer's data.
+   * @param start The position at which to insert the new data.
+   * @param deleteCount The number of items to remove before inserting new data.
+   * @param items The items to insert at the specified position.
+   */
+  splice (start: number, deleteCount: number, ...items: number[]): void {
+    if (this.length < start) {
+      this.pad(start)
+    }
+    this._data.splice(this.cursor, ByteLength.UInt16, ...items)
+  }
+
+  /**
+  * Read a UInt16 number from the smart buffer at the current cursor position, and increment the cursor.
+  * @returns A number represented by the bytes at the current cursor position.
+  */
+  readUInt16 (): number {
+    this.cursor += ByteLength.UInt16
+    const bytes = this.slice(this.cursor - ByteLength.UInt16, this.cursor)
+    return (bytes[0] << 8) | bytes[1]
+  }
+
+  /**
+  * Read a UInt32 number from the smart buffer at the current cursor position, and increment the cursor.
+  * @returns A number represented by the bytes at the current cursor position.
+  */
+  readUInt32 (): number {
+    this.cursor += ByteLength.UInt32
+    const bytes = this.slice(this.cursor - ByteLength.UInt32, this.cursor)
+    return (((bytes[0] << 24) | (bytes[1] << 16)) | (bytes[2] << 8) | bytes[3])
+  }
+
+  /**
+  * Read the specified number of bytes from the smart buffer at the current cursor position, and increment the cursor.
+  * @returns A buffer containing the bytes read from the current cursor position.
+  */
+  readBytes (length: number): Uint8Array {
+    this.cursor += length
+    return this.slice(this.cursor - length, this.cursor)
+  }
+
+  /**
+  * Write a UInt16 number to the smart buffer at the current cursor position, and increment the cursor.
+  * @param number The number to write in UInt16 format at the current cursor position.
+  */
+  writeUInt16 (number: number): void {
+    const bytes = [
+      (number & 0xff00) >> 8,
+      (number & 0x00ff)
+    ]
+    this.splice(this.cursor, ByteLength.UInt16, ...bytes)
+    this.cursor += ByteLength.UInt16
+  }
+
+  /**
+  * Write a UInt32 number to the smart buffer at the current cursor position, and increment the cursor.
+  * @param number The number to write in UInt32 format at the current cursor position.
+  */
+  writeUInt32 (number: number): void {
+    const bytes = [
+      (number & 0xff000000) >> 24,
+      (number & 0x00ff0000) >> 16,
+      (number & 0x0000ff00) >> 8,
+      (number & 0x000000ff)
+    ]
+    this.splice(this.cursor, ByteLength.UInt32, ...bytes)
+    this.cursor += ByteLength.UInt32
+  }
+
+  /**
+  * Write the specified bytes to the smart buffer at the current cursor position, and increment the cursor.
+  * @param buffer The bytes to write at the current cursor position.
+  */
+  writeBytes (buffer: Uint8Array): void {
+    this.splice(this.cursor, buffer.length, ...buffer)
+    this.cursor += buffer.length
+  }
+}

src/structures/server.ts

@@ -1,16 +1,35 @@
-import { BufferReader } from '../buffer-reader'
+import { MAX_DATA_LENGTH } from '../common'
+import { SmartBuffer } from '../smart-buffer'
 
-export class IncomingPacket extends BufferReader {
-  messageType: number
-  senderId: number
-  length: number
-  data: Buffer
+export class IncomingPacket extends SmartBuffer {
+  fields: {
+    messageType: number
+    senderId: number
+    length: number
+    data: Uint8Array
+  }
 
-  constructor (data: Buffer) {
+  constructor (data: ArrayBuffer) {
     super()
-    this.messageType = this.readUInt16()
-    this.senderId = this.readUInt32()
-    this.length = this.readUInt16()
-    this.data = this.readBuffer(this.length)
+    this.data = new Uint8Array(data)
+    this.fields = {
+      messageType: this.readUInt16(),
+      senderId: this.readUInt32(),
+      length: this.readUInt16(),
+      data: this.readBytes(this.length)
+    }
+  }
+}
+
+export class OutgoingPacket extends SmartBuffer {
+  constructor (messageType: number, data: Uint8Array = new Uint8Array(0)) {
+    super()
+    if (data.length > MAX_DATA_LENGTH) {
+      throw RangeError(`Specified data of length ${data.length} exceeds max data length ${MAX_DATA_LENGTH}.`)
+    }
+
+    this.writeUInt16(messageType)
+    this.writeUInt16(data.length)
+    this.writeBytes(data)
   }
 }

src/structures/subscribe.ts

@@ -0,0 +1,22 @@
+import { SmartBuffer } from '../smart-buffer'
+import { OutgoingPacket } from './server'
+
+export class SubscribeMessage extends SmartBuffer {
+  static readonly messageType = 0x0000
+
+  constructor (id: number) {
+    super()
+    const outgoingPacket = new OutgoingPacket(SubscribeMessage.messageType)
+    this.data = outgoingPacket.data
+    this.writeUInt16(id)
+  }
+}
+
+export class Unsubscribe extends OutgoingPacket {
+  static readonly messageType = 0xffff
+
+  constructor (id: number) {
+    super(Unsubscribe.messageType)
+    this.writeUInt16(id)
+  }
+}

tests/buffer-reader.test.ts

@@ -1,96 +0,0 @@
-import { BufferReader } from '../src/buffer-reader'
-
-test('Read a UInt16.', () => {
-  // Given
-  const buffer = Buffer.from([0x30, 0x39])
-
-  // When
-  const smartBuffer = new BufferReader(buffer)
-
-  // Then
-  expect(smartBuffer.readUInt16()).toBe(12345)
-})
-
-test('Read a UInt32.', () => {
-  // Given
-  const buffer = Buffer.from([0x49, 0x96, 0x02, 0xD2])
-
-  // When
-  const smartBuffer = new BufferReader(buffer)
-
-  // Then
-  expect(smartBuffer.readUInt32()).toBe(1234567890)
-})
-
-test('Read a buffer.', () => {
-  // Given
-  const buffer = Buffer.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
-
-  // When
-  const smartBuffer = new BufferReader(buffer)
-
-  // Then
-  expect(smartBuffer.readBuffer(4)).toMatchObject(Buffer.from([0, 1, 2, 3]))
-})
-
-test('Cursor is correctly incremented after reading a UInt16.', () => {
-  // Given
-  const buffer = Buffer.from([0x30, 0x39, 0x1A, 0x85])
-
-  // When
-  const smartBuffer = new BufferReader(buffer)
-
-  // Then
-  expect(smartBuffer.readUInt16()).toBe(12345)
-  expect(smartBuffer.readUInt16()).toBe(6789)
-})
-
-test('Cursor is correctly incremented after reading a buffer.', () => {
-  // Given
-  const buffer = Buffer.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
-
-  // When
-  const smartBuffer = new BufferReader(buffer)
-
-  // Then
-  expect(smartBuffer.readBuffer(4)).toMatchObject(Buffer.from([0, 1, 2, 3]))
-  expect(smartBuffer.readBuffer(4)).toMatchObject(Buffer.from([4, 5, 6, 7]))
-})
-
-test('Cursor is correctly incremented after reading a UInt32.', () => {
-  // Given
-  const buffer = Buffer.from([0x49, 0x96, 0x02, 0xD2, 0x3A, 0xDE, 0x68, 0xB1])
-
-  // When
-  const smartBuffer = new BufferReader(buffer)
-
-  // Then
-  expect(smartBuffer.readUInt32()).toBe(1234567890)
-  expect(smartBuffer.readUInt32()).toBe(987654321)
-})
-
-test('Seek to position below 0 throws range error.', () => {
-  // Given
-  const buffer = Buffer.from([])
-
-  // When
-  const smartBuffer = new BufferReader(buffer)
-
-  // Then
-  expect(() => {
-    smartBuffer.cursor = -1
-  }).toThrow(RangeError)
-})
-
-test('Seek beyond buffer throws range error.', () => {
-  // Given
-  const buffer = Buffer.from([0, 1, 2, 3])
-
-  // When
-  const smartBuffer = new BufferReader(buffer)
-
-  // Then
-  expect(() => {
-    smartBuffer.cursor = 5
-  }).toThrow(RangeError)
-})

tests/smart-buffer.test.ts

@@ -0,0 +1,229 @@
+import { SmartBuffer } from '../src/smart-buffer'
+
+test('Read a UInt16.', () => {
+  // Given
+  const buffer = Uint8Array.from([0x30, 0x39])
+
+  // When
+  const smartBuffer = new SmartBuffer(buffer)
+
+  // Then
+  expect(smartBuffer.readUInt16()).toBe(12345)
+})
+
+test('Read a UInt32.', () => {
+  // Given
+  const buffer = Uint8Array.from([0x49, 0x96, 0x02, 0xD2])
+
+  // When
+  const smartBuffer = new SmartBuffer(buffer)
+
+  // Then
+  expect(smartBuffer.readUInt32()).toBe(1234567890)
+})
+
+test('Read a buffer.', () => {
+  // Given
+  const buffer = Uint8Array.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
+
+  // When
+  const smartBuffer = new SmartBuffer(buffer)
+
+  // Then
+  expect(smartBuffer.readBytes(4)).toMatchObject(Uint8Array.from([0, 1, 2, 3]))
+})
+
+test('Read a UInt16 from an offset.', () => {
+  // Given
+  const buffer = Uint8Array.from([0x00, 0x00, 0x30, 0x39])
+
+  // When
+  const smartBuffer = new SmartBuffer(buffer)
+  smartBuffer.cursor = 2
+
+  // Then
+  expect(smartBuffer.readUInt16()).toBe(12345)
+})
+
+test('Read a UInt32 from an offset.', () => {
+  // Given
+  const buffer = Uint8Array.from([0x00, 0x00, 0x49, 0x96, 0x02, 0xD2])
+
+  // When
+  const smartBuffer = new SmartBuffer(buffer)
+  smartBuffer.cursor = 2
+
+  // Then
+  expect(smartBuffer.readUInt32()).toBe(1234567890)
+})
+
+test('Read a buffer from an offset.', () => {
+  // Given
+  const buffer = Uint8Array.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
+
+  // When
+  const smartBuffer = new SmartBuffer(buffer)
+  smartBuffer.cursor = 2
+
+  // Then
+  expect(smartBuffer.readBytes(4)).toMatchObject(Uint8Array.from([2, 3, 4, 5]))
+})
+
+test('Write a UInt16.', () => {
+  // Given
+  const smartBuffer = new SmartBuffer()
+
+  // When
+  smartBuffer.writeUInt16(12345)
+
+  // Then
+  expect(smartBuffer.data).toMatchObject(Uint8Array.from([0x30, 0x39]))
+})
+
+test('Write a UInt32.', () => {
+  // Given
+  const smartBuffer = new SmartBuffer()
+
+  // When
+  smartBuffer.writeUInt32(1234567890)
+
+  // Then
+  expect(smartBuffer.data).toMatchObject(Uint8Array.from([0x49, 0x96, 0x02, 0xD2]))
+})
+
+test('Write a buffer.', () => {
+  // Given
+  const smartBuffer = new SmartBuffer()
+
+  // When
+  smartBuffer.writeBytes(Uint8Array.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
+
+  // Then
+  expect(smartBuffer.data).toMatchObject(Uint8Array.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
+})
+
+test('Write a UInt16 at an offset.', () => {
+  // Given
+  const smartBuffer = new SmartBuffer()
+
+  // When
+  smartBuffer.cursor = 2
+  smartBuffer.writeUInt16(12345)
+
+  // Then
+  expect(smartBuffer.data).toMatchObject(Uint8Array.from([0x00, 0x00, 0x30, 0x39]))
+})
+
+test('Write a UInt32 at an offset.', () => {
+  // Given
+  const smartBuffer = new SmartBuffer()
+
+  // When
+  smartBuffer.cursor = 2
+  smartBuffer.writeUInt32(1234567890)
+
+  // Then
+  expect(smartBuffer.data).toMatchObject(Uint8Array.from([0x00, 0x00, 0x49, 0x96, 0x02, 0xD2]))
+})
+
+test('Write a buffer at an offset.', () => {
+  // Given
+  const smartBuffer = new SmartBuffer()
+
+  // When
+  smartBuffer.cursor = 2
+  smartBuffer.writeBytes(Uint8Array.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
+
+  // Then
+  expect(smartBuffer.data).toMatchObject(Uint8Array.from([0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
+})
+
+test('Cursor is correctly incremented after reading a UInt16.', () => {
+  // Given
+  const buffer = new Uint8Array(4)
+
+  // When
+  const smartBuffer = new SmartBuffer(buffer)
+
+  // Then
+  smartBuffer.readUInt16()
+  expect(smartBuffer.cursor).toBe(2)
+})
+
+test('Cursor is correctly incremented after reading a UInt32.', () => {
+  // Given
+  const buffer = new Uint8Array(4)
+
+  // When
+  const smartBuffer = new SmartBuffer(buffer)
+
+  // Then
+  smartBuffer.readUInt32()
+  expect(smartBuffer.cursor).toBe(4)
+})
+
+test('Cursor is correctly incremented after reading a buffer.', () => {
+  // Given
+  const buffer = new Uint8Array(8)
+
+  // When
+  const smartBuffer = new SmartBuffer(buffer)
+
+  // Then
+  smartBuffer.readBytes(4)
+  expect(smartBuffer.cursor).toBe(4)
+})
+
+test('Cursor is correctly incremented after writing a UInt16.', () => {
+  // Given
+  const smartBuffer = new SmartBuffer()
+
+  // When
+  smartBuffer.writeUInt16(12345)
+
+  // Then
+  expect(smartBuffer.cursor).toBe(2)
+})
+
+test('Cursor is correctly incremented after writing a UInt32.', () => {
+  // Given
+  const smartBuffer = new SmartBuffer()
+
+  // When
+  smartBuffer.writeUInt32(1234567890)
+
+  // Then
+  expect(smartBuffer.cursor).toBe(4)
+})
+
+test('Cursor is correctly incremented after writing a buffer.', () => {
+  // Given
+  const smartBuffer = new SmartBuffer()
+
+  // When
+  smartBuffer.writeBytes(Uint8Array.from([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
+
+  // Then
+  expect(smartBuffer.cursor).toBe(10)
+})
+
+test('Seek to position below 0 throws range error.', () => {
+  // When
+  const smartBuffer = new SmartBuffer()
+
+  // Then
+  expect(() => {
+    smartBuffer.cursor = -1
+  }).toThrow(RangeError)
+})
+
+test('Pad some data..', () => {
+  // Given
+  const smartBuffer = new SmartBuffer()
+
+  // When
+  smartBuffer.pad(10)
+
+  // Then
+  expect(smartBuffer.length).toBe(10)
+})

webpack.config.js

@@ -0,0 +1,20 @@
+const path = require('path')
+module.exports = {
+  entry: './src/index.ts',
+  module: {
+    rules: [
+      {
+        test: /\.tsx?$/,
+        use: 'ts-loader',
+        exclude: /node_modules/
+      }
+    ]
+  },
+  resolve: {
+    extensions: ['.tsx', '.ts', '.js']
+  },
+  output: {
+    filename: 'bundle.js',
+    path: path.resolve(__dirname, 'dist')
+  }
+}