Method extend

src/jrd/trace/TraceLog.cpp:217–267

}

void TraceLog::extend(FB_SIZE_T size)
{
	TraceLogHeader* header = m_sharedMemory->getHeader();
	const ULONG oldSize = header->allocated;
	const FB_SIZE_T oldUsed = getUsed();

	ULONG newSize = header->allocated * ((header->allocated + size) / header->allocated + 1);
	newSize = MIN(newSize, header->maxSize);

	LocalStatus ls;
	CheckStatusWrapper s(&ls);

	if (!m_sharedMemory->remapFile(&s, newSize, true))
		status_exception::raise(&s);

	header = m_sharedMemory->getHeader();
	header->allocated = newSize;

	if (header->writePos < header->readPos)
	{
		const FB_SIZE_T toMoveW = header->writePos - sizeof(TraceLogHeader);
		const FB_SIZE_T toMoveR = oldSize - header->readPos;

		char* data = reinterpret_cast<char*> (header);
		const FB_SIZE_T deltaSize = newSize - oldSize;

		if (toMoveW < toMoveR)
		{
			if (toMoveW <= deltaSize)
			{
				memcpy(data + oldSize, data + sizeof(TraceLogHeader), toMoveW);
				header->writePos = oldSize + toMoveW;

				if (header->writePos == header->allocated)
					header->writePos = sizeof(TraceLogHeader);
			}
			else
			{
				memcpy(data + oldSize, data + sizeof(TraceLogHeader), deltaSize);
				memcpy(data + sizeof(TraceLogHeader), data + sizeof(TraceLogHeader) + deltaSize, toMoveW - deltaSize);
				header->writePos -= deltaSize;
			}
		}
		else
		{
			memcpy(data + newSize - toMoveR, data + header->readPos, toMoveR);
			header->readPos = newSize - toMoveR;
		}
	}
	fb_assert(oldUsed == getUsed());
}

FB_SIZE_T TraceLog::getUsed()
{