Function makeReplace

src/jrd/SysFunction.cpp:1767–1825

void makeReplace(DataTypeUtilBase* dataTypeUtil, const SysFunction* function, dsc* result,
	int argsCount, const dsc** args)
{
	fb_assert(argsCount >= function->minArgCount);

	bool isNullable = false;
	const dsc* firstBlob = NULL;

	for (int i = 0; i < argsCount; ++i)
	{
		if (args[i]->isNull())
		{
			result->makeNullString();
			return;
		}

		if (args[i]->isNullable())
			isNullable = true;

		if (!firstBlob && args[i]->isBlob())
			firstBlob = args[i];
	}

	const dsc* searched = args[0];
	const dsc* find = args[1];
	const dsc* replacement = args[2];

	if (firstBlob)
		*result = *firstBlob;
	else
	{
		result->clear();
		result->dsc_dtype = dtype_varying;
	}

	result->setBlobSubType(dataTypeUtil->getResultBlobSubType(searched, find));
	result->setBlobSubType(dataTypeUtil->getResultBlobSubType(result, replacement));

	result->setTextType(dataTypeUtil->getResultTextType(searched, find));
	result->setTextType(dataTypeUtil->getResultTextType(result, replacement));

	if (!firstBlob)
	{
		const int searchedLen = dataTypeUtil->convertLength(searched, result);
		const int findLen = dataTypeUtil->convertLength(find, result);
		const int replacementLen = dataTypeUtil->convertLength(replacement, result);

		if (findLen == 0)
			result->dsc_length = dataTypeUtil->fixLength(result, searchedLen) + static_cast<USHORT>(sizeof(USHORT));
		else
		{
			result->dsc_length = dataTypeUtil->fixLength(result,
				MAX(searchedLen, searchedLen + (searchedLen / findLen) * (replacementLen - findLen))) +
				static_cast<USHORT>(sizeof(USHORT));
		}
	}

	result->setNullable(isNullable);