Run results for: looped parsing

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36

Browser: Chrome 132

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
test1	4423763.0 Ops/sec
test2	4663258.0 Ops/sec
inlined	1391944.4 Ops/sec

Script Preparation code:


let schema=[
  //[0,0,0,8,4,15]
  "aaaiep",
  ""
]

let P=(idx, view, buffer)=> {
  let sc = schema[idx];
  let grandObject = [];
  let newObj = grandObject, decoder = new TextDecoder(), end_idx = sc.length, begin_idx = 0, repeats = 0, i = 0, offset = 0, rep_ct = 0;

  while (i < end_idx) {
    let field = sc.charCodeAt(i) - 0x61;
    let top = field >> 2;
    let code = field & 3;
    let candidate = 0;

    // don't read if its an end token...
    switch (code) {
      case 0:candidate=view.getInt8(offset,true);++offset;break;
      case 1:candidate=view.getInt16(offset,true);offset+=2;break;
      case 2:candidate=view.getInt32(offset,true);offset+=4;break;
    }

    if (top == 0) {
      newObj.push(candidate);
    } else if (top == 1) {
      newObj.push(decoder.decode(buffer.slice(offset, offset+candidate)));
      offset += candidate;
    } else if (top == 2) {
      repeats = candidate;
      rep_ct = 0;
      newObj.push(new Array(candidate).fill(null).map(() => []));
      newObj = newObj.at(-1).at(0);
      begin_idx = i;
    } else {
      ++rep_ct;

      if (rep_ct >= repeats) {
        rep_ct = 0;
        newObj = grandObject;
      } else {
        i = begin_idx;
        newObj = grandObject.at(-1)[rep_ct];
      }
    }

    ++i;
  }

  return grandObject;//[grandObject, offset];
}


let arrData = [21, 19, 10, 5, 3, 97, 97 + 2, 97 + 5,  3, 97, 97 + 2, 97 + 5,  3, 97, 97 + 2, 97 + 5,  3, 97, 97 + 2, 97 + 5,  3, 97, 97 + 2, 97 + 5];

// Step 2: Create a Uint8Array from arrData
let uint8Arr = new Uint8Array(arrData);

// Step 3: Get the underlying ArrayBuffer from the Uint8Array
let arrayBuf = uint8Arr.buffer;

// Step 4: Create a DataView based on the ArrayBuffer
let dataView = new DataView(arrayBuf);

// Example usage:
console.log(uint8Arr);   // Uint8Array(7) [21, 19, 10, 3, 97, 99, 102]
console.log(arrayBuf);   // ArrayBuffer with byteLength of 7
console.log(dataView);   // DataView { byteLength: 7, ... }

Tests:

test1
P(0,dataView, arrayBuf)
test2
const jsonStrings = [ '{"name": "Alice", "age": 30, "city": "Wonderland"}', '{"title": "Book Title", "author": "Some Author", "pages": 350}', '{"status": "success", "code": 50, "data": [1, 2, 3]}', '{"coordinates": {"x": 10, "y": 0}, "visible": true}', '{"items": ["apple", "banana", "ear"], "count": 3}', '{"status": "success", "code": 220, "data": [1, 2, 3]}', '{"coordinates": {"x": 10, "y": 10}, "visible": true}', '{"items": ["apple", "banana", "pear"], "count": 3}', '{"status": "success", "code": 3, "data": [1, 2, 3]}', '{"coordinates": {"x": 10, "y": 20}, "visible": true}', '{"items": ["apple", "banana", "pear"], "count": 3}', '{"status": "success", "code": 11, "data": [1, 2, 3]}', '{"coordinates": {"x": 10, "y": 20}, "visible": true}', '{"items": ["apple", "banana", "pear"], "count": 3}', '{"status": "success", "code": 4, "data": [1, 2, 3]}', '{"coordinates": {"x": 10, "y": 20}, "visible": true}', '{"items": ["apple", "banana", "pear"], "count": 3}', '{"status": "success", "code": 4, "data": [1, 2, 3]}', '{"coordinates": {"x": 10, "y": 5}, "visible": true}', '{"items": ["apple", "banana", "pear"], "count": 3}', '{"users": [{"id": 1}, {"id": 2}], "hasMore": false}' ]; // A function to pick a random JSON string from the array function getRandomJsonString() { // Generate a random index based on the length of the array const randomIndex = Math.floor(Math.random() * jsonStrings.length); // Return the JSON string at that index return jsonStrings[randomIndex]; } JSON.parse(getRandomJsonString());
inlined
let newObj=[],bytes = 0, decoder = new TextDecoder(); let ofs=0;dataView.getInt8(ofs,true);ofs+=1; dataView.getInt8(ofs,true);ofs+=1; dataView.getInt8(ofs,true);ofs+=1; let strlen=dataView.getInt8(ofs,true);ofs+=1; newObj.push(uint8Arr.subarray(ofs, ofs+strlen));

Run results for: looped parsing

test1

test2

inlined