C++ (Cpp) FragmentList::Remove Examples

Example #1

File: ipv6.cpp Project: Barrett17/haiku-contacts-kit-old

status_t
FragmentPacket::AddFragment(uint16 start, uint16 end, net_buffer* buffer,
	bool lastFragment)
{
	// restart the timer
	gStackModule->set_timer(&fTimer, FRAGMENT_TIMEOUT);

	if (start >= end) {
		// invalid fragment
		return B_BAD_DATA;
	}

	// Search for a position in the list to insert the fragment

	FragmentList::ReverseIterator iterator = fFragments.GetReverseIterator();
	net_buffer* previous = NULL;
	net_buffer* next = NULL;
	while ((previous = iterator.Next()) != NULL) {
		if (previous->fragment.start <= start) {
			// The new fragment can be inserted after this one
			break;
		}

		next = previous;
	}

	// See if we already have the fragment's data

	if (previous != NULL && previous->fragment.start <= start
		&& previous->fragment.end >= end) {
		// we do, so we can just drop this fragment
		gBufferModule->free(buffer);
		return B_OK;
	}

	fIndex = buffer->index;
		// adopt the buffer's device index

	TRACE("    previous: %p, next: %p", previous, next);

	// If we have parts of the data already, truncate as needed

	if (previous != NULL && previous->fragment.end > start) {
		TRACE("    remove header %d bytes", previous->fragment.end - start);
		gBufferModule->remove_header(buffer, previous->fragment.end - start);
		start = previous->fragment.end;
	}
	if (next != NULL && next->fragment.start < end) {
		TRACE("    remove trailer %d bytes", next->fragment.start - end);
		gBufferModule->remove_trailer(buffer, next->fragment.start - end);
		end = next->fragment.start;
	}

	// Now try if we can already merge the fragments together

	// We will always keep the last buffer received, so that we can still
	// report an error (in which case we're not responsible for freeing it)

	if (previous != NULL && previous->fragment.end == start) {
		fFragments.Remove(previous);

		buffer->fragment.start = previous->fragment.start;
		buffer->fragment.end = end;

		status_t status = gBufferModule->merge(buffer, previous, false);
		TRACE("    merge previous: %s", strerror(status));
		if (status != B_OK) {
			fFragments.Insert(next, previous);
			return status;
		}

		fFragments.Insert(next, buffer);

		// cut down existing hole
		fBytesLeft -= end - start;

		if (lastFragment && !fReceivedLastFragment) {
			fReceivedLastFragment = true;
			fBytesLeft -= IPV6_MAXPACKET - end;
		}

		TRACE("    hole length: %d", (int)fBytesLeft);

		return B_OK;
	} else if (next != NULL && next->fragment.start == end) {
		net_buffer* afterNext = (net_buffer*)next->link.next;
		fFragments.Remove(next);

		buffer->fragment.start = start;
		buffer->fragment.end = next->fragment.end;

		status_t status = gBufferModule->merge(buffer, next, true);
		TRACE("    merge next: %s", strerror(status));
		if (status != B_OK) {
			// Insert "next" at its previous position
			fFragments.Insert(afterNext, next);
			return status;
		}

		fFragments.Insert(afterNext, buffer);

		// cut down existing hole
		fBytesLeft -= end - start;

		if (lastFragment && !fReceivedLastFragment) {
			fReceivedLastFragment = true;
			fBytesLeft -= IPV6_MAXPACKET - end;
		}

		TRACE("    hole length: %d", (int)fBytesLeft);

		return B_OK;
	}

	// We couldn't merge the fragments, so we need to add it as is

	TRACE("    new fragment: %p, bytes %d-%d", buffer, start, end);

	buffer->fragment.start = start;
	buffer->fragment.end = end;
	fFragments.Insert(next, buffer);

	// update length of the hole, if any
	fBytesLeft -= end - start;

	if (lastFragment && !fReceivedLastFragment) {
		fReceivedLastFragment = true;
		fBytesLeft -= IPV6_MAXPACKET - end;
	}

	TRACE("    hole length: %d", (int)fBytesLeft);

	return B_OK;
}