public object FindKey(object key)
{
int hashValue = _GetHash(key);
LinearHashtable subTable = _GetSubTable(hashValue);
return(subTable._FindKey(key, hashValue));
}
public void DeleteKey(object key)
{
int hashValue = _GetHash(key);
LinearHashtable subTable = _GetSubTable(hashValue);
subTable._DeleteKey(key, hashValue);
}
// used to share code between the two constructors
// out parameters are necessary for readonly variables (can only be set in ctor)
private void _CtorMakeSubTables(int subTableCount, out LinearHashtable[] subTables, out int subTableMask)
{
subTables = new LinearHashtable[subTableCount];
subTableMask = subTableCount - 1;
// power of 2?
if ((subTableMask & subTableCount) != 0)
{
subTableMask = -1;
}
}
// paramaters -
// bool onlyAdd
// false - allows overwriting at key
// true - throws exception if key exists
//
// return - returns the previous value at key
// Notes: return can be null key is new or if value at key is null
public object Insert(object key, object value, bool onlyAdd)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
int hashValue = _GetHash(key);
LinearHashtable subTable = _GetSubTable(hashValue);
return(subTable._Insert(key, value, hashValue, onlyAdd));
}
public LkrHashtable(
string name, // an identifier for debugging
int initialCapacity, // initial size of hash table (entries, not buckets like C++ LkrHash)
double maxLoad, // bound on the average chain length
int subTableCount, // number of subordinate hash tables
IHashCodeProvider hcp,
IComparer comparer)
{
_hcp = hcp;
if (initialCapacity < MIN_INITIAL_CAPACITY)
{
// initialCapacity must be greater than MIN_INITIAL_CAPACITY
throw new ArgumentOutOfRangeException("initialCapacity", initialCapacity, null);
}
_CtorCheckParameters(maxLoad, subTableCount);
if (subTableCount == 0) // get default from initialCapacity
{
subTableCount = _GetSubTableCount(initialCapacity, maxLoad);
}
Debug.Trace("LkrHashtable", "LkrHashtable: name=" + name +
" subtables=" + subTableCount + ", capacity=" + initialCapacity);
_CtorMakeSubTables(subTableCount, out _subTables, out _subTableMask);
for (int i = 0; i < subTableCount; ++i)
{
string subTableName = name + " sub " + i.ToString();
_subTables[i] = new LinearHashtable(
subTableName,
initialCapacity / subTableCount,
maxLoad,
hcp,
comparer);
}
}
public LkrHashtable(
string name,
TableSize size,
double maxLoad,
int subTableCount,
IHashCodeProvider hcp,
IComparer comparer)
{
_hcp = hcp;
if (size == TableSize.Default)
{
size = DEFAULT_META_TABLE_SIZE;
}
_CtorCheckParameters(maxLoad, subTableCount);
if (subTableCount == 0)
{
subTableCount = _SubTableCountFromTableSize(size);
}
Debug.Trace("LkrHashtable", "LkrHashtable.ctor name=" + name + " size=" +
size + " subtables=" + subTableCount);
_CtorMakeSubTables(subTableCount, out _subTables, out _subTableMask);
for (int i = 0; i < subTableCount; ++i)
{
string subTableName = name + " sub " + i.ToString();
_subTables[i] = new LinearHashtable(
subTableName,
size,
maxLoad,
hcp,
comparer);
}
}
