Record SPSegment::lookup(TID tid) {
// TODO assert(tid.getPage() is part of this segment);
BufferFrame frame = bm->fixPage(tid.getPage(), false);
SlottedPage* page = reinterpret_cast<SlottedPage*>(frame.getData());
Slot* slot = page->getSlot(tid.getSlot());
if (slot->isMoved()) {
// Slot was indirected: Lookup that TID the slot points to recursively.
bm->unfixPage(frame, false);
return this->lookup(TID(slot->slot));
} else if (slot->length() == 0 && slot->offset() == 0) {
// Slot is empty: Return empty record
bm->unfixPage(frame, false);
return Record(0, nullptr);
} else {
// Slot has content: Return record with content.
bm->unfixPage(frame, false);
return Record(slot->length(), slot->getRecord()->getData());
}
}
Record SPSegment::inPlaceLookup(TID tid) {
// TODO assert(tid.getPage() is part of this segment);
BufferFrame frame = bm->fixPage(tid.getPage(), false);
SlottedPage* page = reinterpret_cast<SlottedPage*>(frame.getData());
Slot* slot = page->getSlot(tid.getSlot());
if (slot->isMoved() || slot->isEmpty()) {
// Slot is empty: Return empty record
bm->unfixPage(frame, false);
return Record(0, nullptr);
} else {
// Slot has content: Return record with content.
bm->unfixPage(frame, false);
return Record(slot->length(), slot->getRecord()->getData());
}
}