Method init

src/jrd/recsrc/SortedStream.cpp:182–284

}

Sort* SortedStream::init(thread_db* tdbb) const
{
	Request* const request = tdbb->getRequest();

	m_next->open(tdbb);

	// Initialize for sort. If this is really a project operation,
	// establish a callback routine to reject duplicate records.

	AutoPtr<Sort> scb(FB_NEW_POOL(request->req_sorts.getPool())
		Sort(tdbb->getDatabase(), &request->req_sorts,
			 m_map->length, m_map->keyItems.getCount(), m_map->keyItems.getCount(),
			 m_map->keyItems.begin(),
			 ((m_map->flags & FLAG_PROJECT) ? rejectDuplicate : nullptr), 0));

	// Pump the input stream dry while pushing records into sort. For
	// each record, map all fields into the sort record. The reverse
	// mapping is done in get_sort().

	dsc to, temp;

	while (m_next->getRecord(tdbb))
	{
		// "Put" a record to sort. Actually, get the address of a place
		// to build a record.

		UCHAR* data = nullptr;
		scb->put(tdbb, reinterpret_cast<ULONG**>(&data));

		// Zero out the sort key. This solves a multitude of problems.

		memset(data, 0, m_map->length);

		// Loop thru all field (keys and hangers on) involved in the sort.
		// Be careful to null field all unused bytes in the sort key.

		const SortMap::Item* const end_item = m_map->items.begin() + m_map->items.getCount();
		for (const SortMap::Item* item = m_map->items.begin(); item < end_item; item++)
		{
			to = item->desc;
			to.dsc_address = data + (IPTR) to.dsc_address;
			bool flag = false;
			dsc* from = nullptr;

			if (item->node)
			{
				from = EVL_expr(tdbb, request, item->node);
				if (request->req_flags & req_null)
					flag = true;
			}
			else
			{
				from = &temp;

				record_param* const rpb = &request->req_rpb[item->stream];

				if (item->fieldId < 0)
				{