Function move_to_string

src/jrd/blb.cpp:2683–2732

static void move_to_string(thread_db* tdbb, dsc* fromDesc, dsc* toDesc)
{
/**************************************
 *
 *      m o v e _ t o _ s t r i n g
 *
 **************************************
 *
 * Functional description
 *      Perform an assignment from a blob to another datatype.
 *
 **************************************/
	SET_TDBB(tdbb);

	fb_assert(DTYPE_IS_BLOB_OR_QUAD(fromDesc->dsc_dtype));
	fb_assert(!DTYPE_IS_BLOB_OR_QUAD(toDesc->dsc_dtype));

	dsc blobAsText;
	blobAsText.dsc_dtype = dtype_text;

	if (DTYPE_IS_TEXT(toDesc->dsc_dtype))
		blobAsText.dsc_ttype() = toDesc->dsc_ttype();
	else
		blobAsText.dsc_ttype() = ttype_ascii;

	Request* request = tdbb->getRequest();
	jrd_tra* transaction = request ? request->req_transaction : tdbb->getTransaction();
	transaction = transaction->getOuter();

	UCharBuffer bpb;
	BLB_gen_bpb_from_descs(fromDesc, &blobAsText, bpb);

	blb* blob = blb::open2(tdbb, transaction,
		(bid*) fromDesc->dsc_address, bpb.getCount(), bpb.begin());

	const CharSet* fromCharSet = INTL_charset_lookup(tdbb, fromDesc->dsc_scale);
	const CharSet* toCharSet = INTL_charset_lookup(tdbb, INTL_GET_CHARSET(&blobAsText));

	HalfStaticArray<UCHAR, BUFFER_SMALL> buffer;
	buffer.getBuffer((blob->blb_length / fromCharSet->minBytesPerChar()) * toCharSet->maxBytesPerChar());
	const ULONG len = blob->BLB_get_data(tdbb, buffer.begin(), buffer.getCapacity(), true);

	if (len > MAX_STR_SIZE)
		ERR_post(Arg::Gds(isc_arith_except) << Arg::Gds(isc_blob_truncation));

	blobAsText.dsc_address = buffer.begin();
	blobAsText.dsc_length = (USHORT) len;

	MOV_move(tdbb, &blobAsText, toDesc);
}


// Release a blob and associated blocks. Among other things, disconnect it from the transaction.