encodePackedVarintsField function

List<int> encodePackedVarintsField(List<int> buffer, int fieldNumber, List<int> values)

Encode a packed repeated varints field (wire type 2): tag + varint(total_len) + concatenated varint-encoded values.

Used for repeated scalar fields that use varint encoding (int32, int64, uint32, uint64, sint32, sint64, bool, enum).

Proto3 rule: does not emit anything if values is empty.

Returns buffer with the field bytes appended.

Implementation

List<int> encodePackedVarintsField(
  List<int> buffer,
  int fieldNumber,
  List<int> values,
) {
  if (values.isEmpty) return buffer;
  // Encode all values into a temporary buffer to determine total byte length.
  List<int> temp = [];
  for (int i = 0; i < values.length; i++) {
    encodeVarint(temp, values[i]);
  }
  encodeTag(buffer, fieldNumber, _wireTypeLEN);
  encodeBytes(buffer, temp);
  return buffer;
}