Add a browser-only implementation for environments without Buffer (#5)

extremeheat · May 5, 2024 · 040788a · 040788a
1 parent eee82cb
commit 040788a
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Showing 5 changed files with 416 additions and 2 deletions.
diff --git a/package.json b/package.json
@@ -2,7 +2,7 @@
   "name": "bytewriter",
   "version": "1.0.2",
   "description": "Simple binary byte stream implementation with support for reading/writing numbers, strings, and varints (zigzag or unsigned) in both little and big endian encoding",
-  "main": "index.js",
+  "main": "src/index.js",
   "scripts": {
     "test": "mocha --reporter spec --exit",
     "pretest": "npm run lint",

diff --git a/src/browser.js b/src/browser.js
@@ -0,0 +1,339 @@
+const MAX_ALLOC_SIZE = 1024 * 1024 * 2 // 2MB
+const DEFAULT_ALLOC_SIZE = 10000
+
+class ByteStream {
+  constructor (buffer, maxSize) {
+    if (buffer instanceof ArrayBuffer) {
+      this.buffer = new Uint8Array(buffer)
+    } else if (buffer instanceof Uint8Array) {
+      this.buffer = buffer
+    } else {
+      this.buffer = new Uint8Array(DEFAULT_ALLOC_SIZE)
+    }
+    this.readOffset = 0
+    this.writeOffset = 0
+    this.size = this.buffer.length
+    this.guardLimit = maxSize || MAX_ALLOC_SIZE
+    this.view = new DataView(this.buffer.buffer)
+  }
+
+  resizeForWriteIfNeeded (bytes) {
+    if ((this.writeOffset + bytes) > this.size) {
+      this.size *= 2
+      const newBuffer = new Uint8Array(this.size)
+      newBuffer.set(this.buffer)
+      this.buffer = newBuffer
+      this.view = new DataView(this.buffer.buffer)
+    }
+    if (this.size > this.guardLimit) throw new Error('Buffer size exceeded guard limit')
+  }
+
+  readByte () {
+    return this.buffer[this.readOffset++]
+  }
+
+  // Write unsigned
+  writeUInt8 (value) {
+    this.resizeForWriteIfNeeded(1)
+    this.buffer[this.writeOffset] = value
+    this.writeOffset += 1
+  }
+
+  writeUInt16LE (value) {
+    this.resizeForWriteIfNeeded(2)
+    this.view.setUint16(this.writeOffset, value, true)
+    this.writeOffset += 2
+  }
+
+  writeUInt32LE (value) {
+    this.resizeForWriteIfNeeded(4)
+    this.view.setUint32(this.writeOffset, value, true)
+    this.writeOffset += 4
+  }
+
+  writeUInt64LE (value) {
+    this.resizeForWriteIfNeeded(8)
+    this.view.setBigUint64(this.writeOffset, BigInt(value), true)
+    this.writeOffset += 8
+  }
+
+  writeFloatLE (value) {
+    this.resizeForWriteIfNeeded(4)
+    this.view.setFloat32(this.writeOffset, value, true)
+    this.writeOffset += 4
+  }
+
+  writeDoubleLE (value) {
+    this.resizeForWriteIfNeeded(8)
+    this.view.setFloat64(this.writeOffset, value, true)
+    this.writeOffset += 8
+  }
+
+  writeUInt16BE (value) {
+    this.resizeForWriteIfNeeded(2)
+    this.view.setUint16(this.writeOffset, value, false)
+    this.writeOffset += 2
+  }
+
+  writeUInt32BE (value) {
+    this.resizeForWriteIfNeeded(4)
+    this.view.setUint32(this.writeOffset, value, false)
+    this.writeOffset += 4
+  }
+
+  writeUInt64BE (value) {
+    this.resizeForWriteIfNeeded(8)
+    this.view.setBigUint64(this.writeOffset, BigInt(value), false)
+    this.writeOffset += 8
+  }
+
+  // Write signed
+  writeInt8 (value) {
+    this.resizeForWriteIfNeeded(1)
+    this.buffer[this.writeOffset] = value
+    this.writeOffset += 1
+  }
+
+  writeInt16LE (value) {
+    this.resizeForWriteIfNeeded(2)
+    this.view.setInt16(this.writeOffset, value, true)
+    this.writeOffset += 2
+  }
+
+  writeInt32LE (value) {
+    this.resizeForWriteIfNeeded(4)
+    this.view.setInt32(this.writeOffset, value, true)
+    this.writeOffset += 4
+  }
+
+  writeInt64LE (value) {
+    this.resizeForWriteIfNeeded(8)
+    this.view.setBigInt64(this.writeOffset, BigInt(value), true)
+    this.writeOffset += 8
+  }
+
+  writeInt16BE (value) {
+    this.resizeForWriteIfNeeded(2)
+    this.view.setInt16(this.writeOffset, value, false)
+    this.writeOffset += 2
+  }
+
+  writeInt32BE (value) {
+    this.resizeForWriteIfNeeded(4)
+    this.view.setInt32(this.writeOffset, value, false)
+    this.writeOffset += 4
+  }
+
+  writeInt64BE (value) {
+    this.resizeForWriteIfNeeded(8)
+    this.view.setBigInt64(this.writeOffset, BigInt(value), false)
+    this.writeOffset += 8
+  }
+
+  // Write floats
+  writeFloatBE (value) {
+    this.resizeForWriteIfNeeded(4)
+    this.view.setFloat32(this.writeOffset, value, false)
+    this.writeOffset += 4
+  }
+
+  writeDoubleBE (value) {
+    this.resizeForWriteIfNeeded(8)
+    this.view.setFloat64(this.writeOffset, value, false)
+    this.writeOffset += 8
+  }
+
+  // Read
+  readUInt8 () {
+    const value = this.buffer[this.readOffset]
+    this.readOffset += 1
+    return value
+  }
+
+  readUInt16LE () {
+    const value = this.view.getUint16(this.readOffset, true)
+    this.readOffset += 2
+    return value
+  }
+
+  readUInt32LE () {
+    const value = this.view.getUint32(this.readOffset, true)
+    this.readOffset += 4
+    return value
+  }
+
+  readUInt64LE () {
+    const value = this.view.getBigUint64(this.readOffset, true)
+    this.readOffset += 8
+    return value
+  }
+
+  readUInt16BE () {
+    const value = this.view.getUint16(this.readOffset, false)
+    this.readOffset += 2
+    return value
+  }
+
+  readUInt32BE () {
+    const value = this.view.getUint32(this.readOffset, false)
+    this.readOffset += 4
+    return value
+  }
+
+  readUInt64BE () {
+    const value = this.view.getBigUint64(this.readOffset, false)
+    this.readOffset += 8
+    return value
+  }
+
+  readInt8 () {
+    const value = this.buffer[this.readOffset]
+    this.readOffset += 1
+    return value
+  }
+
+  readInt16LE () {
+    const value = this.view.getInt16(this.readOffset, true)
+    this.readOffset += 2
+    return value
+  }
+
+  readInt32LE () {
+    const value = this.view.getInt32(this.readOffset, true)
+    this.readOffset += 4
+    return value
+  }
+
+  readInt64LE () {
+    const value = this.view.getBigInt64(this.readOffset, true)
+    this.readOffset += 8
+    return value
+  }
+
+  // Strings
+  writeStringNT (value, encoding = 'utf8') {
+    const encoder = new TextEncoder(encoding)
+    const encodedString = encoder.encode(value)
+    this.resizeForWriteIfNeeded(encodedString.length + 1)
+    this.buffer.set(encodedString, this.writeOffset)
+    this.buffer[this.writeOffset + encodedString.length] = 0 // Null terminator
+    this.writeOffset += encodedString.length + 1
+  }
+
+  writeStringRaw (value, encoding = 'utf8') {
+    const encoder = new TextEncoder(encoding)
+    const encodedString = encoder.encode(value)
+    this.resizeForWriteIfNeeded(encodedString.length)
+    this.buffer.set(encodedString, this.writeOffset)
+    this.writeOffset += encodedString.length
+  }
+
+  writeBuffer (value) {
+    this.resizeForWriteIfNeeded(value.byteLength)
+    this.buffer.set(value, this.writeOffset)
+    this.writeOffset += value.byteLength
+  }
+
+  readBuffer (length) {
+    const value = this.buffer.subarray(this.readOffset, this.readOffset + length)
+    this.readOffset += length
+    return value
+  }
+
+  // Varints
+  // Write a signed varint
+  writeVarInt (value) {
+    this.resizeForWriteIfNeeded(9)
+    let offset = 0
+    while (value & ~0x7F) {
+      this.buffer[this.writeOffset + offset] = (value & 0x7f) | 0x80
+      value = value >>> 7
+      offset += 1
+    }
+    this.buffer[this.writeOffset + offset] = value
+    this.writeOffset += offset + 1
+  }
+
+  // Read a signed varint
+  readVarInt () {
+    let value = 0
+    let offset = 0
+    let byte
+    do {
+      byte = this.buffer[this.readOffset + offset]
+      value |= (byte & 0x7f) << (7 * offset)
+      offset += 1
+    } while (byte & 0x80)
+    this.readOffset += offset
+    return value
+  }
+
+  // Write a signed 64-bit varint
+  writeVarLong (value) {
+    value = typeof value === 'bigint' ? value : BigInt(value)
+    this.resizeForWriteIfNeeded(9)
+    value = BigInt.asUintN(64, value)
+    let offset = 0
+    while (value & ~0x7Fn) {
+      this.buffer[this.writeOffset + offset] = Number((value & 0x7fn) | 0x80n)
+      value = value >> 7n
+      offset += 1
+    }
+    this.buffer[this.writeOffset + offset] = Number(value)
+    this.writeOffset += offset + 1
+  }
+
+  // Read a signed 64-bit varint
+  readVarLong () {
+    let value = 0n
+    let offset = 0
+    let byte
+    do {
+      byte = this.buffer[this.readOffset + offset]
+      value |= BigInt(byte & 0x7f) << BigInt(7 * offset)
+      offset += 1
+    } while (byte & 0x80)
+    this.readOffset += offset
+    return BigInt.asIntN(64, value)
+  }
+
+  // Write a zigzag encoded, signed varint upto 32bits
+  writeZigZagVarInt (value) {
+    const zigzag = (value << 1) ^ (value >> 31)
+    this.writeVarInt(zigzag)
+  }
+
+  // Read a zigzag encoded, signed varint upto 32bits
+  readZigZagVarInt () {
+    const value = this.readVarInt()
+    return (value >>> 1) ^ -(value & 1)
+  }
+
+  // Write a zigzag encoded, signed varint upto 64bits
+  writeZigZagVarLong (value) {
+    value = typeof value === 'bigint' ? value : BigInt(value)
+    const zigzag = (value << 1n) ^ (value >> 63n)
+    this.writeVarLong(zigzag)
+  }
+
+  // Read a zigzag encoded, signed varint upto 64bits
+  readZigZagVarLong () {
+    const value = this.readVarLong()
+    return (value >> 1n) ^ -(value & 1n)
+  }
+
+  // Extra
+  peekUInt8 () {
+    return this.buffer[this.readOffset]
+  }
+
+  peek () {
+    return this.buffer[this.readOffset]
+  }
+
+  getBuffer () {
+    return this.buffer.subarray(0, this.writeOffset)
+  }
+}
+
+module.exports = ByteStream
diff --git a/src/index.js b/src/index.js
@@ -0,0 +1,6 @@
+const NodeBinaryStream = require('./node')
+const BrowserBinaryStream = require('./browser')
+
+module.exports = typeof Buffer === 'undefined'
+  ? BrowserBinaryStream
+  : NodeBinaryStream
diff --git a/index.js → src/node.js b/index.js → src/node.js