parsePgBinaryArray static method

List<String?>? parsePgBinaryArray(List<int> bytes)

Parse the PostgreSQL binary ARRAY wire format (one-dimensional) into a List of UTF-8 element strings (enum labels, text, …).

Layout: int32 ndim, int32 hasNull, int32 elemOid, then per dimension {int32 size, int32 lowerBound}, then per element {int32 byteLength (-1 = NULL), payload bytes}. Returns null when the bytes do not parse cleanly as such an array (callers fall back to plain UTF-8 decode).

Implementation

static List<String?>? parsePgBinaryArray(List<int> bytes) {
  if (bytes.length < 12) return null;
  // The driver already hands us a Uint8List; only copy when it doesn't,
  // and decode elements as views over the same buffer (no per-element
  // sublist copies).
  final u8 = bytes is Uint8List ? bytes : Uint8List.fromList(bytes);
  final data = ByteData.sublistView(u8);
  final ndim = data.getInt32(0);
  final hasNull = data.getInt32(4);
  if (hasNull != 0 && hasNull != 1) return null;
  if (ndim == 0) return u8.length == 12 ? <String?>[] : null;
  if (ndim != 1 || u8.length < 20) return null;

  final size = data.getInt32(12);
  if (size < 0 || size > 100000) return null;

  final elements = <String?>[];
  var offset = 20;
  for (var i = 0; i < size; i++) {
    if (offset + 4 > u8.length) return null;
    final len = data.getInt32(offset);
    offset += 4;
    if (len == -1) {
      elements.add(null);
      continue;
    }
    if (len < 0 || offset + len > u8.length) return null;
    elements.add(utf8.decode(Uint8List.sublistView(u8, offset, offset + len),
        allowMalformed: true));
    offset += len;
  }
  return offset == u8.length ? elements : null;
}