Function stringToUTF16

js/sql-debug.js:935–953

(str, outPtr, maxBytesToWrite)

// Returns the number of bytes written, EXCLUDING the null terminator.

function stringToUTF16(str, outPtr, maxBytesToWrite) {
  // Backwards compatibility: if max bytes is not specified, assume unsafe unbounded write is allowed.
  if (maxBytesToWrite === undefined) {
    maxBytesToWrite = 0x7FFFFFFF;
  }
  if (maxBytesToWrite < 2) return 0;
  maxBytesToWrite -= 2; // Null terminator.
  var startPtr = outPtr;
  var numCharsToWrite = (maxBytesToWrite < str.length*2) ? (maxBytesToWrite / 2) : str.length;
  for (var i = 0; i < numCharsToWrite; ++i) {
    // charCodeAt returns a UTF-16 encoded code unit, so it can be directly written to the HEAP.
    var codeUnit = str.charCodeAt(i); // possibly a lead surrogate
    HEAP16[((outPtr)>>1)]=codeUnit;
    outPtr += 2;
  }
  // Null-terminate the pointer to the HEAP.
  HEAP16[((outPtr)>>1)]=0;
  return outPtr - startPtr;
}


// Returns the number of bytes the given Javascript string takes if encoded as a UTF16 byte array, EXCLUDING the null terminator byte.