/**
* Searches through the pages loking for a page with enough space to store r. If no space
* is found, it grows the segment
*
* @param r: the record
*
* @return rtrn: TID identifying the location where r was stored
*/
TID SPSegment::insert(Record& r) {
TID rtrn;
SlottedPage* spHolder = NULL;
// instantiate new record pointer by given r
Record* newRec = new Record(r.getLen(), r.getData());
// try to find slotted page which can hold record
for (auto it = spMap.begin(); it != spMap.end(); ++it) {
if (it->second->getFreeSpace() >= (newRec->getLen() + (2 * sizeof(uint16_t)) + sizeof(bool))) {
spHolder = it->second;
rtrn.pageId = it->first;
break;
}
}
// page to hold record found
if (spHolder != NULL) {
// insert record into slotted page
rtrn.slotId = spHolder->insertRecord(*newRec);
// write changes back to disk
if (!writeToFrame(spHolder, rtrn.pageId)) {
cerr << "Cannot write slotted page into frame" << endl;
}
}
// no page found to hold record, so increase the segment
else {
// just need one more page
vector<uint64_t> neededExtents;
// grow by 10 pages
vector<uint64_t> newExtents = grow(10);
// create new slotted page
SlottedPage* sp = new SlottedPage();
sp->getHeader()->freeSpace = bm->getPageSize() - sizeof(Header);
rtrn.pageId = newExtents.front();
// insert record into slotted page
rtrn.slotId = sp->insertRecord(*newRec);
// write changes back to disk
if (writeToFrame(sp, rtrn.pageId)) {
spMap[rtrn.pageId] = sp;
} else {
cerr << "Cannot write slotted page into frame" << endl;
}
}
return rtrn;
}
/**
* Constructor: initializes slotted pages
*/
SPSegment::SPSegment(vector<uint64_t> freeExtents, uint64_t segId, FSISegment *fsi,BufferManager * bm) :
Segment(freeExtents, segId, fsi, bm) {
for (unsigned i = 0; i < getSize(); i++) {
SlottedPage* sp = new SlottedPage();
sp->getHeader()->freeSpace = bm->getPageSize() - sizeof(Header);
uint64_t pageId = at(i);
// write slottet page to disk
if (writeToFrame(sp, pageId)) {
spMap.insert(make_pair(pageId, sp));
} else {
cerr << "Cannot write slotted page into frame" << endl;
}
}
cout << "SPSegment extents: " << std::endl;
for (unsigned i = 0; i < extents.size(); ++i) {
std::cout << "value: " << i << ": " << extents.at(i) << std::endl;
}
}
