PageIdIterator(const std::vector<Extent>& extents, PageId target)
: extent(0), pageID(kInvalidPageId), extents(&extents)
{
for(;extent<extents.size(); extent++)
if(extents[extent].begin().toInteger() <= target.toInteger() && target.toInteger() < extents[extent].end().toInteger()) {
pageID = target;
return;
}
}
void inc(uint64_t count)
{
assert(pageID != kInvalidPageId);
while(count!=0 && pageID!=kInvalidPageId) {
// Next extent
if(pageID == (*extents)[extent].end()) {
extent++;
if(extent >= extents->size())
pageID = kInvalidPageId;
else
pageID = (*extents)[extent].begin();
}
//
uint64_t leftInThisExtent = (*extents)[extent].end().toInteger() - pageID.toInteger();
if(leftInThisExtent > count) {
pageID = PageId(pageID.toInteger() + count);
count = 0;
} else {
count -= leftInThisExtent;
pageID = (*extents)[extent].end();
}
}
}
