//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// TreeCache::Add():
// Add a position to the cache if applicable..
//
bool
TreeCache::Add (Position * pos, treeT * pTree, Filter * filter)
{
// Is this tree in the cache already?
int index = LookupIndex (pos);
if (index >= 0) {
// It is! Set the MostRecentIndex:
MostRecentIndex = index;
return true;
}
// Quick test for the common condition of the cache being full and
// this tree having a count too low to be added:
if (Policy == TREECACHE_Smallest && NumInUse == CacheSize
&& pTree->totalCount < LowestTotal) {
return false;
}
// Now, we add this tree to the end of the cache it is not full, or
// if it is full, check if its count is high enough to be added.
if (NumInUse == CacheSize) {
// Cache is full!
// If replacing the smallest, we know its total is high enough
// to be added, from the test above.
if (Policy == TREECACHE_Oldest) {
// Replace the oldest node:
MostRecentIndex = (MostRecentIndex+1) % CacheSize;
AddTree (MostRecentIndex, pos, pTree, filter);
} else {
// Replace the smallest node:
AddTree (LowestTotalIndex, pos, pTree, filter);
// Find the NEW lowest total, the next tree to be evicted:
LowestTotal = pTree->totalCount;
for (uint i=0; i < CacheSize; i++) {
if (Cache[i].tree.totalCount < LowestTotal) {
LowestTotal = Cache[i].tree.totalCount;
LowestTotalIndex = i;
}
}
}
} else {
// Cache is not yet full. Add the position to the cache:
AddTree (NumInUse, pos, pTree, filter);
// Update LowestTotal if necessary:
if (NumInUse == 0 || pTree->totalCount < LowestTotal) {
LowestTotal = pTree->totalCount;
LowestTotalIndex = NumInUse;
}
NumInUse++;
}
return true;
}
/* lookup a index using a string */
uint8 MarshalStringTable::LookupIndex( const std::string& str )
{
return LookupIndex( str.c_str() );
}
