Method openBlob

src/jrd/jrd.cpp:3677–3728

JBlob* JAttachment::openBlob(CheckStatusWrapper* user_status, ITransaction* tra, ISC_QUAD* blob_id,
	unsigned int bpb_length, const unsigned char* bpb)
{
/**************************************
 *
 *	g d s _ $ o p e n _ b l o b 2
 *
 **************************************
 *
 * Functional description
 *	Open an existing blob.
 *
 **************************************/
	blb* blob = NULL;

	try
	{
		JTransaction* const jt = getTransactionInterface(user_status, tra);
		EngineContextHolder tdbb(user_status, this, FB_FUNCTION);

		jrd_tra* transaction = jt->getHandle();
		validateHandle(tdbb, transaction);
		check_database(tdbb);

		try
		{
			const bid* id = reinterpret_cast<bid*>(blob_id);

			if (blob_id->gds_quad_high)
				transaction->checkBlob(tdbb, id, NULL, true);

			blob = blb::open2(tdbb, transaction, id, bpb_length, bpb, true);
		}
		catch (const Exception& ex)
		{
			transliterateException(tdbb, ex, user_status, "JAttachment::openBlob");
			return NULL;
		}
	}
	catch (const Exception& ex)
	{
		ex.stuffException(user_status);
		return NULL;
	}

	successful_completion(user_status);

	JBlob* jb = FB_NEW JBlob(blob, getStable());
	jb->addRef();
	blob->blb_interface = jb;
	return jb;
}


void JTransaction::prepare(CheckStatusWrapper* user_status, unsigned int msg_length, const unsigned char* msg)