more dataview replacements

src/decoders/chunk.ts

@@ -1,16 +1,16 @@
 import { Chunk } from '../models/chunk';
 
 export default (buffer: Uint8Array): Chunk => {
-  let offset = 0;
-  const view = new DataView(buffer.buffer, buffer.byteOffset, buffer.byteLength);
-  const id = view.getUint16(offset, true);
-  offset += 2;
+  if (buffer.length < 4) {
+    throw new Error('Chunk buffer must be at least 4 bytes');
+  }
+
+  const id = (buffer[1] << 8) + buffer[0];
 
   // NOTE(jwetzell): this data is split up as 1 bit for hasSubchunks and 15 bits for the dataLen
-  const combinedLengthAndFlag = view.getUint16(offset, true);
+  const combinedLengthAndFlag = (buffer[3] << 8) + buffer[2];
   const hasSubchunks = combinedLengthAndFlag > 32768;
   const dataLen = hasSubchunks ? combinedLengthAndFlag - 32768 : combinedLengthAndFlag;
-  offset += 2;
 
   const header = {
     id,
@@ -18,7 +18,7 @@ export default (buffer: Uint8Array): Chunk => {
     hasSubchunks,
   };
 
-  const chunkData = buffer.subarray(offset, offset + header.dataLen);
+  const chunkData = buffer.subarray(4, 4 + header.dataLen);
 
   const chunk = {
     chunkData,