Function UTF8ArrayToString

sqlite-wasm-opfs/jswasm/sqlite3.js:348–385

(heapOrArray, idx, maxBytesToRead)

function UTF8ArrayToString(heapOrArray, idx, maxBytesToRead) {
  var endIdx = idx + maxBytesToRead;
  var endPtr = idx;
  
  
  
  while (heapOrArray[endPtr] && !(endPtr >= endIdx)) ++endPtr;

  if (endPtr - idx > 16 && heapOrArray.buffer && UTF8Decoder) {
    return UTF8Decoder.decode(heapOrArray.subarray(idx, endPtr));
  }
  var str = '';
  
  while (idx < endPtr) {
    
    
    
    
    var u0 = heapOrArray[idx++];
    if (!(u0 & 0x80)) { str += String.fromCharCode(u0); continue; }
    var u1 = heapOrArray[idx++] & 63;
    if ((u0 & 0xE0) == 0xC0) { str += String.fromCharCode(((u0 & 31) << 6) | u1); continue; }
    var u2 = heapOrArray[idx++] & 63;
    if ((u0 & 0xF0) == 0xE0) {
      u0 = ((u0 & 15) << 12) | (u1 << 6) | u2;
    } else {
      u0 = ((u0 & 7) << 18) | (u1 << 12) | (u2 << 6) | (heapOrArray[idx++] & 63);
    }

    if (u0 < 0x10000) {
      str += String.fromCharCode(u0);
    } else {
      var ch = u0 - 0x10000;
      str += String.fromCharCode(0xD800 | (ch >> 10), 0xDC00 | (ch & 0x3FF));
    }
  }
  return str;
}