column_get_bool

col.cc

typedef struct {
	std::shared_ptr<arrow::Array> chunk;
	int64_t offset;
	const char *error;
} chunk_t;

chunk_t find_chunk(void *vp, long long i, int typ) {
	chunk_t ct = {nullptr, 0, nullptr};

  auto column = (Column *)vp;
	if (column == nullptr) {
		ct.error = "null pointer";
		return ct;
	}

  if (column->ptr->type()->id() != typ) {
		ct.error = "wrong type";
		return ct;
  }

  if ((i < 0) || (i >= column->ptr->length())) {
		ct.error = "index out of range";
		return ct;
  }

  auto chunks = column->ptr->data();
	ct.offset = i;

	for (int c = 0; c < chunks->num_chunks(); c++) {
		auto chunk = chunks->chunk(c);
		if (ct.offset < chunk->length()) {
			ct.chunk = chunk;
			return ct;
		}
		ct.offset -= chunk->length();
	}

	ct.error = "can't get here";
	return ct;
}	

int column_bool_at(void *vp, long long i) {
	auto res = find_chunk(vp, i, BOOL_DTYPE);
	if (res.error != nullptr) {
		return -1;
	}

	auto arr = (arrow::BooleanArray *)(res.chunk.get());
  return arr->Value(res.offset);
}