refactor the whole damn thing

src/Binary/Decoder.js

@@ -0,0 +1,87 @@
+import utf8 from 'utf-8'
+
+export default class BinaryDecoder {
+  constructor (buffer) {
+    if (buffer instanceof ArrayBuffer) {
+      this.uint8arr = new Uint8Array(buffer)
+    } else if (buffer instanceof Uint8Array || (typeof Buffer !== 'undefined' && buffer instanceof Buffer)) {
+      this.uint8arr = buffer
+    } else {
+      throw new Error('Expected an ArrayBuffer or Uint8Array!')
+    }
+    this.pos = 0
+  }
+
+  clone (newPos = this.pos) {
+    let decoder = new BinaryDecoder(this.uint8arr)
+    decoder.pos = newPos
+    return decoder
+  }
+
+  get length () {
+    return this.uint8arr.length
+  }
+
+  skip8 () {
+    this.pos++
+  }
+
+  readUint8 () {
+    return this.uint8arr[this.pos++]
+  }
+
+  readUint32 () {
+    let uint =
+      this.uint8arr[this.pos] +
+      (this.uint8arr[this.pos + 1] << 8) +
+      (this.uint8arr[this.pos + 2] << 16) +
+      (this.uint8arr[this.pos + 3] << 24)
+    this.pos += 4
+    return uint
+  }
+
+  peekUint8 () {
+    return this.uint8arr[this.pos]
+  }
+
+  readVarUint () {
+    let num = 0
+    let len = 0
+    while (true) {
+      let r = this.uint8arr[this.pos++]
+      num = num | ((r & 0b1111111) << len)
+      len += 7
+      if (r < 1 << 7) {
+        return num >>> 0 // return unsigned number!
+      }
+      if (len > 35) {
+        throw new Error('Integer out of range!')
+      }
+    }
+  }
+
+  readVarString () {
+    let len = this.readVarUint()
+    let bytes = new Array(len)
+    for (let i = 0; i < len; i++) {
+      bytes[i] = this.uint8arr[this.pos++]
+    }
+    return utf8.getStringFromBytes(bytes)
+  }
+
+  peekVarString () {
+    let pos = this.pos
+    let s = this.readVarString()
+    this.pos = pos
+    return s
+  }
+
+  readOpID () {
+    let user = this.readVarUint()
+    if (user !== 0xFFFFFF) {
+      return [user, this.readVarUint()]
+    } else {
+      return [user, this.readVarString()]
+    }
+  }
+}