BufferFrame* BPlusSegment<K,V>::fixLeafFor(const K& key, const bool exclusive) const{
BufferFrame* pageOfKey = &bm.fixPage(segmentId, root, exclusive);
while(!isLeaf(pageOfKey->getData())){
BPlusPage<K, PageID> page(pageOfKey->getData(), pageSize, cmp);
PageID nextPage;
try{
nextPage = page.lookupSmallestGreaterThan(key).value;
}catch(NotFoundException e){
//upper exists?
if (page.getUpperExists()){
nextPage = page.getUpper();
}else{
bm.unfixPage(*pageOfKey, false);
throw NotFoundException();
}
}
BufferFrame* oldBF = pageOfKey;
pageOfKey = &bm.fixPage(segmentId, nextPage, exclusive);
bm.unfixPage(*oldBF, false);
}
return pageOfKey;
}
V BPlusSegment<K, V>::findGreatestKey(BufferFrame* startFrame) const{
BufferFrame* pageFrame = startFrame;
bool isFirst = true;
while(!isLeaf(pageFrame->getData())){
BPlusPage<K, PageID> page(pageFrame->getData(), pageSize, cmp);
PageID nextPage;
if (page.getUpperExists()){
nextPage = page.getUpper();
}else{
nextPage = page.getValueOfHighestKey();
}
BufferFrame* oldBF = pageFrame;
pageFrame = &bm.fixPage(segmentId, nextPage, false);
//don't unfix first frame, as it is controlled by caller
if (isFirst){
isFirst = false;
}else{
bm.unfixPage(*oldBF, false);
}
}
BPlusPage<K, V> page(pageFrame->getData(), pageSize, cmp);
K highestKey = page.getHighestKey();
if (!isFirst) bm.unfixPage(*pageFrame, false);
return highestKey;
}
inline void BTree<KeyType, KeyComparator>::insert(KeyType key, TID tid) {
size_t currHeight = 0;
uint64_t currPageId = rootPageId;
BufferFrame *parentFrame = nullptr;
BufferFrame *currFrame = nullptr;
InnerNode<KeyType, KeyComparator> *parentNode = nullptr;
InnerNode<KeyType, KeyComparator> *currNode = nullptr;
while (!isLeafHeight(currHeight)) {
if (parentFrame != nullptr) {
bufferManager.unfixPage(*parentFrame, true);
}
parentFrame = currFrame;
parentNode = currNode;
currFrame = &bufferManager.fixPage(this->segmentId, currPageId, true);
currNode = reinterpret_cast<InnerNode<KeyType, KeyComparator> *>(currFrame->getData());
if (!currNode->hasSpaceForOneMoreEntry()) {
if (parentNode == nullptr) {
auto newNode = createEmptyNode(currPageId);
parentFrame = newNode.first;
parentNode = newNode.second;
currHeight++;
}
auto splitResult = splitInnerNode(currNode, currFrame, currPageId,
parentNode, key);
currFrame = splitResult.first;
currNode = splitResult.second;
}
currPageId = currNode->getNextNode(key, this->smallerComparator);
currHeight++;
}
// we are now at leaf height - the currPageId points to a leaf
if (parentFrame != nullptr) {
bufferManager.unfixPage(*parentFrame, true);
}
parentFrame = currFrame;
parentNode = currNode;
currNode = nullptr;
currFrame = &bufferManager.fixPage(this->segmentId, currPageId, true);
auto leaf = reinterpret_cast<Leaf<KeyType, KeyComparator> *>(currFrame->getData());
if (!leaf->hasSpaceForOneMoreEntry()) {
if (parentNode == nullptr) {
auto newNode = createEmptyNode(currPageId);
parentFrame = newNode.first;
parentNode = newNode.second;
}
auto splitResult = splitLeaf(leaf, currFrame, currPageId, parentNode, key);
currFrame = splitResult.first;
leaf = splitResult.second;
}
if (parentFrame != nullptr) {
bufferManager.unfixPage(*parentFrame, true);
}
leaf->insertDefiniteFit(key, tid, smallerComparator);
bufferManager.unfixPage(*currFrame, true);
treeSize++;
}
std::vector<uint64_t> BTree<K, Comp>::lookupRange(K key1, K key2) {
std::vector < uint64_t > resultSet;
//Get Leaf of lower key
K leftK, rightK;
if (smaller(key1, key2)) {
leftK = key1;
rightK = key2;
} else {
leftK = key2;
rightK = key1;
}
BufferFrame* leafFrame = traverseToLeaf(leftK, false);
Node<K, Comp>* leaf = reinterpret_cast<Node<K, Comp>*>(leafFrame->getData());
uint64_t pos = leaf->findKeyPos(leftK, smaller);
if (pos >= leaf->count || smaller(leaf->keyValuePairs[pos].first, leftK)) {
//No matching key was found
bufferManager.unfixPage(*leafFrame, false);
return resultSet;
}
while (true) {
while (pos < leaf->count) {
if (smaller(rightK, leaf->keyValuePairs[pos].first)) {
bufferManager.unfixPage(*leafFrame, false);
return resultSet;
}
resultSet.push_back(leaf->keyValuePairs[pos].second);
pos++;
}
if (leaf->next == std::numeric_limits<uint64_t>::max()) {
//There is no next leaf --> return
bufferManager.unfixPage(*leafFrame, false);
return resultSet;
} else {
//Continue in next Leaf. Get it and unfix current Leaf
uint64_t nextLeafPID = leaf->next;
bufferManager.unfixPage(*leafFrame, false);
leafFrame = &bufferManager.fixPage(nextLeafPID, false);
leaf = reinterpret_cast<Node<K, Comp>*>(leafFrame->getData());
pos = 0;
}
}
bufferManager.unfixPage(*leafFrame, false);
return resultSet;
}
BufferFrame* BTree<K, Comp>::createNewRoot() {
BufferFrame* newFrame = &bufferManager.fixPage(nextFreePage++, true);
rootPID = newFrame->pageId;
Node<K, Comp>* newRoot = reinterpret_cast<Node<K, Comp>*>(newFrame->getData());
*newRoot = Node<K, Comp>(false);
return newFrame;
}
SplitResult<K> BPlusSegment<K,V>::splitPage(BufferFrame &frame, const bool inner){
//TODO: find a better way to work with the types here
if (inner){
//notice: K, PageID here instead of V
BPlusPage<K, PageID> page(frame.getData(), pageSize, cmp);
assert(!page.hasAdditionalSpace());
PageID siblingPageID = pageCount;
BufferFrame& siblingFrame = bm.fixPage(segmentId, siblingPageID, true);
pageCount++;
//notice: K, PageID here instead of V
BPlusPage<K, PageID> sibling(siblingFrame.getData(), pageSize, cmp);
sibling.initialize();
sibling.setLeaf(false);
sibling.takeUpperFrom(page);
//handle upper key on split
if (page.getUpperExists()){
K newKey = findGreatestKey(&frame);
sibling.insert(newKey, page.getUpper());
page.setUpperNotExists();
}
K siblingHighestKey = sibling.getHighestKey();
K pageHighestKey = page.getHighestKey();
bm.unfixPage(siblingFrame, true);
return SplitResult<K>(siblingPageID, siblingHighestKey, pageHighestKey, true, frame);
}else{
BPlusPage<K, V> page(frame.getData(), pageSize, cmp);
assert(!page.hasAdditionalSpace());
PageID siblingPageID = pageCount;
BufferFrame& siblingFrame = bm.fixPage(segmentId, siblingPageID, true);
pageCount++;
BPlusPage<K, V> sibling(siblingFrame.getData(), pageSize, cmp);
sibling.initialize();
sibling.takeUpperFrom(page);
K siblingHighestKey = sibling.getHighestKey();
K pageHighestKey = page.getHighestKey();
bm.unfixPage(siblingFrame, true);
return SplitResult<K>(siblingPageID, siblingHighestKey, pageHighestKey, true, frame);
}
}
bool BTree<K, Comp>::erase(K key) {
BufferFrame* leafFrame = traverseToLeaf(key, true);
Node<K, Comp>* leaf = reinterpret_cast<Node<K, Comp>*>(leafFrame->getData());
bool deleted = leaf->deleteKey(key, smaller);
bufferManager.unfixPage(*leafFrame, true);
if (deleted) {
elements--; //update size of BTree
}
return deleted;
}
inline bool BTree<KeyType, KeyComparator>::searchForKey(
KeyType key, TID &tid, uint64_t pageId, size_t currentHeight) {
BufferFrame *currentFrame = &bufferManager.fixPage(this->segmentId, pageId, false);
bool result;
if (isLeafHeight(currentHeight)) {
Leaf<KeyType, KeyComparator> *leaf = reinterpret_cast<Leaf<KeyType, KeyComparator> *>(
currentFrame->getData());
result = leaf->lookup(key, smallerComparator, &tid);
} else {
//we haven't reached the leaves yet
InnerNode<KeyType, KeyComparator> *currNode = reinterpret_cast<InnerNode<KeyType, KeyComparator> *> (
currentFrame->getData());
pageId = currNode->getNextNode(key, smallerComparator);
result = searchForKey(key, tid, pageId, currentHeight + 1);
}
//return page as result was received and page is no longer required
bufferManager.unfixPage(*currentFrame, false);
return result;
}
inline std::vector<TID> BTree<KeyType, KeyComparator>::lookupRange(KeyType begin, KeyType end) {
KeyType left = begin;
KeyType right = end;
/* if given end-limit is lower than begin, we need to swap both borders*/
if (smallerComparator(end, begin)) {
left = end;
right = begin;
}
std::vector<TID> lookupSet;
Leaf<KeyType, KeyComparator> leftLeaf = getLeaf(left);
int position = EntriesHelper::findPosition<KeyType, KeyComparator, TID>(
leftLeaf.entries, left,
0, leftLeaf.header.keyCount,
smallerComparator);
BufferFrame * currentFrame = nullptr;
while (true) {
while (position < leftLeaf.header.keyCount) {
Entry<KeyType, TID> entry = leftLeaf.entries[position];
if (begin <= entry.key && entry.key <= end){
lookupSet.push_back(entry.value);
}
position++;
}
if (position == leftLeaf.header.keyCount) {
//reached end of leaf and need to check the next leaf
uint64_t nextLeaf = leftLeaf.header.nextLeafPageId;
if (nextLeaf != LeafHeader::INVALID_PAGE_ID) {
// set next leaf and reset position to first entry
if (currentFrame != nullptr){
bufferManager.unfixPage(*currentFrame, false);
currentFrame = nullptr;
}
currentFrame = &bufferManager.fixPage(this->segmentId, nextLeaf, true);
leftLeaf = * reinterpret_cast<Leaf<KeyType, KeyComparator> *>(currentFrame->getData());
position = 0;
} else {
// end of leaves reached, we cannot look further so we return the set
break;
}
} else {
break;
}
}
if (currentFrame != nullptr){
bufferManager.unfixPage(*currentFrame, false);
}
return lookupSet;
}
boost::optional<uint64_t> BTree<K, Comp>::lookup(K key) {
BufferFrame* leafFrame = traverseToLeaf(key, false);
Node<K, Comp>* leaf = reinterpret_cast<Node<K, Comp>*>(leafFrame->getData());
uint64_t pos = leaf->findKeyPos(key, smaller);
uint64_t tid = std::numeric_limits<uint64_t>::max();
bool found = false;
if (pos < leaf->count && isEqual(key, leaf->keyValuePairs[pos].first, smaller)) {
found = true;
tid = leaf->keyValuePairs[pos].second;
}
bufferManager.unfixPage(*leafFrame, false);
return boost::optional<uint64_t> { found, tid };
}
// gets the requested data from file and puts a new bufferFrame into the hashmap
// if required, this method replaces frames in the buffer
void BufferManager::cachePageFromFile(unsigned pageId) {
// lock hash table and lru queue
pthread_rwlock_wrlock(&buffer_latch);
pthread_rwlock_wrlock(&lruBuffer_latch);
// if buffer is full, replace a frame in buffer with page from file
if(lruBuffer.size() >= size) {
// Search for the first lockable buffer frame
BufferFrame *toBeFreed = NULL;
for(vector<BufferFrame*>::iterator i = lruBuffer.begin(); i != lruBuffer.end(); ++i) {
// try to lock this frame, if not possible continue with next frame in lruBuffer
int lockResult = pthread_rwlock_trywrlock(&((*i)->latch));
//cout << "lockResult: " << lockResult << " for pageId " << (*i)->pageId << endl;
if(lockResult == 0) {
pthread_rwlock_unlock(&((*i)->latch));
// cout << (*i)->pageId << " wr_locked and unlocked\n";
toBeFreed = *i;
// if we found our candidate frame, delete it from the buffers and deallocate the memory
int cnt = buffer.erase(toBeFreed->pageId); // delete from hash map
assert(cnt == 1);
toBeFreed->writeDataToFile(); // save changes
lruBuffer.erase(i);
//free mmapped memory
if (munmap(toBeFreed->getData(), FRAME_SIZE) == -1) {
cerr << "Error un-mmapping the file";
}
delete toBeFreed; // deallocate memory
break;
}
}
if(toBeFreed==NULL) {
cerr<<"no candidate was found => release locks and return!!!";
pthread_rwlock_unlock(&lruBuffer_latch);
pthread_rwlock_unlock(&buffer_latch);
return;
}
}
// add new frame to hash map and append to end of lruBuffer
BufferFrame *bf = new BufferFrame(file, pageId);
buffer[pageId] = bf;
lruBuffer.push_back(bf);
// release locks
pthread_rwlock_unlock(&lruBuffer_latch);
pthread_rwlock_unlock(&buffer_latch);
}
BufferFrame* BTree<K, Comp>::traverseToLeaf(K key, bool exclusiveLeaf) {
//latch the root
BufferFrame* curFrame = &bufferManager.fixPage(rootPID, exclusiveLeaf);
Node<K, Comp>* curNode = reinterpret_cast<Node<K, Comp>*>(curFrame->getData());
BufferFrame* parFrame = NULL;
while (!curNode->isLeaf()) {
//unlatch parent
if (parFrame != NULL) {
bufferManager.unfixPage(*parFrame, false);
}
parFrame = curFrame;
uint64_t pos = curNode->findKeyPos(key, smaller);
uint64_t nextPID =
(pos == curNode->count) ?
curNode->next : curNode->keyValuePairs[pos].second;
//latch the next level
curFrame = &bufferManager.fixPage(nextPID, exclusiveLeaf);
curNode = reinterpret_cast<Node<K, Comp>*>(curFrame->getData());
}
if (parFrame != NULL) {
bufferManager.unfixPage(*parFrame, false);
}
return curFrame;
}
bool SPSegment::remove(TID tid){
// TODO assert(tid.getPage() is part of this segment);
BufferFrame frame = bm->fixPage(tid.getPage(), true);
SlottedPage* page = reinterpret_cast<SlottedPage*>(frame.getData());
unsigned space = page->remove(tid.getSlot());
// Update FSI
this->fsi[tid.getPage()] = space;
bm->unfixPage(frame, true);
if (tid.tid == lastTID.tid) {
// TODO Update lastTID
}
return true;
}
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());
}
}
TID SPSegment::insert(const Record& r){
// Find page with enough space for r
uint64_t pageId = this->lastPage + 1;
for (auto it = this->fsi.rbegin(); it != this->fsi.rend(); it++) {
if (it->second >= r.getLen()) {
pageId = it->first;
break;
}
}
// If necessary, create new SlottedPage
BufferFrame frame = bm->fixPage(pageId, true);
SlottedPage* page = reinterpret_cast<SlottedPage*>(frame.getData());
if (pageId > this->lastPage) {
*page = SlottedPage();
this->lastPage++;
if (lastPage > 1l << 48) throw "Max page number reached.";
}
// TODO Reorder record ?
// Write to page
unsigned slotNum = page->insert(r);
bm->unfixPage(frame, true);
// Update lastTID
TID newTID = TID(pageId, slotNum);
if (newTID.tid > this->lastTID.tid) {
this->lastTID = newTID;
}
// Update FSI
this->fsi[newTID.getPage()] -= r.getLen() + (slotNum == page->getMaxSlot() ? sizeof(Slot) : 0);
return newTID;
}
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());
}
}
/**
* Reads a slotted page from buffer-frame by pageId and manages sp-map
*
* @param pageId: the page id
*
* @return rtrn: SlottedPage
*/
SlottedPage* SPSegment::readFromFrame(uint64_t pageId) {
SlottedPage* rtrn = NULL;
BufferFrame frame = bm->fixPage(pageId, false);
try {
// 1st step: deserialize
rtrn = SlottedPage::getDeserialized((char*) frame.getData());
// 2nd step: update sp-map
spMap[pageId] = rtrn;
} catch (exception& e) {
cerr << "An exception occurred while reading slotted page from frame: " << e.what() << endl;
rtrn = NULL;
}
bm->unfixPage(frame, false);
return rtrn;
}
/**
* Writes a slotted page into a given buffer-frame
*
* @param sp: the slotted page
* @param pageId: the page id
*
* @return rtrn: whether successfully or not
*/
bool SPSegment::writeToFrame(SlottedPage* sp, uint64_t pageId) {
bool rtrn = true;
BufferFrame frame = bm->fixPage(pageId, true);
try {
// 1st step: serialize
char* spSer = sp->getSerialized();
// 2nd step: write into frame data pointer
memcpy(frame.getData(), spSer, bm->getPageSize());
} catch (exception& e) {
cerr << "An exception occurred while writing slotted page to frame: " << e.what() << endl;
rtrn = false;
}
bm->unfixPage(frame, rtrn);
return rtrn;
}
Leaf<KeyType, KeyComparator> BTree<KeyType, KeyComparator>::getMostLeftLeaf() {
BufferFrame *currentFrame = &bufferManager.fixPage(this->segmentId, rootPageId, false);
int currentDepth = 0;
BufferFrame *parentFrame = nullptr;
while (currentDepth != height) {
InnerNode<KeyType, KeyComparator> *curNode = reinterpret_cast<InnerNode<KeyType, KeyComparator> *> (currentFrame->getData());
if (parentFrame != nullptr) {
bufferManager.unfixPage(*parentFrame, false);
}
Entry<KeyType, uint64_t> entry = curNode->entries[0]; //most left value = 1
uint64_t pageId = entry.value;
parentFrame = currentFrame;
currentFrame = &bufferManager.fixPage(this->segmentId, pageId, false);
currentDepth++;
}
if (parentFrame != nullptr) {
bufferManager.unfixPage(*parentFrame, false);
}
Leaf<KeyType, KeyComparator> *leaf = reinterpret_cast<Leaf<KeyType, KeyComparator> *>(currentFrame->getData());
bufferManager.unfixPage(*currentFrame, false);
return *leaf;
}
Leaf<KeyType, KeyComparator> &BTree<KeyType, KeyComparator>::getLeaf(KeyType key) {
BufferFrame *frame = findFrameForKey(key, false);
Leaf<KeyType, KeyComparator> *leaf = reinterpret_cast<Leaf<KeyType, KeyComparator> *>(frame->getData());
bufferManager.unfixPage(*frame, false);
return *leaf;
}
BufferFrame *BTree<KeyType, KeyComparator>::findFrameForKey(KeyType key, bool exclusive) {
BufferFrame *currentFrame = &bufferManager.fixPage(this->segmentId, rootPageId, exclusive);
int currentDepth = 0;
BufferFrame *parentFrame = nullptr;
while (!isLeafHeight(currentDepth)) {
InnerNode<KeyType, KeyComparator> *curNode = reinterpret_cast<InnerNode<KeyType, KeyComparator> *> (currentFrame->getData());
if (parentFrame != nullptr) {
bufferManager.unfixPage(*parentFrame, false);
}
int nextPageId = curNode->getNextNode(key, smallerComparator);
parentFrame = currentFrame;
currentFrame = &bufferManager.fixPage(this->segmentId, nextPageId, exclusive);
currentDepth++;
}
if (parentFrame != nullptr) {
bufferManager.unfixPage(*parentFrame, false);
}
//frame is fixed and has to be unfixed by the caller!!
return currentFrame;
}
bool BTree<K, Comp>::insert(K key, uint64_t tid) {
//latch the root
BufferFrame* curFrame = &bufferManager.fixPage(rootPID, true);
Node<K, Comp>* curNode = reinterpret_cast<Node<K, Comp>*>(curFrame->getData());
BufferFrame* parFrame = NULL;
while (!curNode->isLeaf()) {
if (curNode->count >= maxNodeSize) {
// --> split to safe inner pages
if (parFrame == NULL) {
//Need to create a new root (parent) first
parFrame = createNewRoot();
}
BufferFrame* newFrame = &bufferManager.fixPage(nextFreePage++, true);
K splitKey = curNode->split(curFrame->pageId, newFrame, parFrame, smaller);
//determine correct node and release the other one
if (smaller(key, splitKey)) {
bufferManager.unfixPage(*newFrame, true);
} else {
curNode = reinterpret_cast<Node<K, Comp>*>(newFrame->getData());
bufferManager.unfixPage(*curFrame, true);
curFrame = newFrame;
}
}
//release the parent node
if (parFrame != NULL) {
bufferManager.unfixPage(*parFrame, true); //TODO only set true when parent is really dirty?
}
parFrame = curFrame;
//latch the next level
uint64_t pos = curNode->findKeyPos(key, smaller);
uint64_t nextPID =
(pos == curNode->count) ?
curNode->next : curNode->keyValuePairs[pos].second;
curFrame = &bufferManager.fixPage(nextPID, true);
curNode = reinterpret_cast<Node<K, Comp>*>(curFrame->getData());
}
Node<K, Comp>* leaf = reinterpret_cast<Node<K, Comp>*>(curNode);
if (leaf->count >= maxNodeSize) {
if (parFrame == NULL) {
parFrame = createNewRoot();
}
BufferFrame* newFrame = &bufferManager.fixPage(nextFreePage++, true);
K splitKey = leaf->split(curFrame->pageId, newFrame, parFrame, smaller);
if (smaller(key, splitKey)) {
bufferManager.unfixPage(*newFrame, true);
} else {
leaf = reinterpret_cast<Node<K, Comp>*>(newFrame->getData());
bufferManager.unfixPage(*curFrame, true);
curFrame = newFrame;
}
}
if (parFrame != NULL) {
bufferManager.unfixPage(*parFrame, true); //TODO: only mark dirty when parent was actually updated
}
bool insertSuccessful = leaf->insertKey(key, tid, smaller);
if (insertSuccessful) {
elements++;
}
bufferManager.unfixPage(*curFrame, true);
return insertSuccessful;
}
bool SPSegment::update(TID tid, const Record& r){
Record r_old = this->lookup(tid);
unsigned len_old = r_old.getLen();
unsigned len_new = r.getLen();
BufferFrame frame = bm->fixPage(tid.getPage(), true);
SlottedPage* page = reinterpret_cast<SlottedPage*>(frame.getData());
if(len_old == len_new){
// If size doesn't change, use memcpy
memcpy(page->getSlot(tid.getSlot())->getRecord(), &r, r.getLen());
} else if(len_old > len_new){
// Record has become smaller
memcpy(page->getSlot(tid.getSlot())->getRecord(), &r, r.getLen());
// TODO Update freeSpace of page
// TODO update FSI
} else {
// Record has become larger
unsigned freeSpaceOnPage = page->remove(tid.getSlot());
this->fsi[tid.getPage()] = freeSpaceOnPage;
if (freeSpaceOnPage >= len_new) {
// It fits on the page after removal
page->insert(r);
} else {
// Even after removal it is too large
// Get another page
uint64_t sndPageId = this->lastPage + 1;
for (auto it = this->fsi.rbegin(); it != this->fsi.rend(); it++) {
if (it->second >= r.getLen()) {
sndPageId = it->first;
break;
}
}
BufferFrame sndFrame = bm->fixPage(sndPageId, true);
// Create a new SlottedPage if necessary
SlottedPage* sndPage = reinterpret_cast<SlottedPage*>(sndFrame.getData());
if (sndPageId > this->lastPage) {
*sndPage = SlottedPage();
this->lastPage++;
if (lastPage > 1l << 48) throw "Max page number reached.";
}
Slot* fstSlot = page->getSlot(tid.getSlot());
assert(fstSlot->isEmpty());
// Insert into new page
unsigned sndSlotNum = sndPage->insert(r);
this->fsi[sndPageId] -= r.getLen() + (sndSlotNum == sndPage->getMaxSlot() ? sizeof(Slot) : 0);
// Update first slot to directo to second page.
*fstSlot = Slot(TID(sndPageId, sndSlotNum));
bm->unfixPage(sndFrame, true);
}
}
bm->unfixPage(frame, true);
return true;
}