@@ -116,102 +116,100 @@ struct CHashTableSlotT
* of pointers allocated elsewhere.
*
* Supports: Add/Find/Remove of Titems.
* Your Titem must meet some extra requirements to be CHashTableT
* compliant:
* - its constructor/destructor (if any) must be public
* - if the copying of item requires an extra resource management,
* you must define also copy constructor
* - must support nested type (struct, class or typedef) Titem::Key
* that defines the type of key class for that item
* - must support public method:
* const Key& GetKey() const; // return the item's key object
* In addition, the Titem::Key class must support:
* - public method that calculates key's hash:
* int CalcHash() const;
* - public 'equality' operator to compare the key with another one
* bool operator==(const Key &other) const;
*/
template <class Titem_, int Thash_bits_>
class CHashTableT {
public:
typedef Titem_ Titem; // make Titem_ visible from outside of class
typedef typename Titem_::Key Tkey; // make Titem_::Key a property of HashTable
static const int Thash_bits = Thash_bits_; // publish num of hash bits
static const int Tcapacity = 1 << Thash_bits; // and num of slots 2^bits
protected:
/**
* each slot contains pointer to the first item in the list,
* Titem contains pointer to the next item - GetHashNext(), SetHashNext()
typedef CHashTableSlotT<Titem_> Slot;
Slot m_slots[Tcapacity]; // here we store our data (array of blobs)
int m_num_items; // item counter
/* default constructor */
inline CHashTableT() : m_num_items(0)
{
}
/** static helper - return hash for the given key modulo number of slots */
inline static int CalcHash(const Tkey &key)
int32 hash = key.CalcHash();
if ((8 * Thash_bits) < 32) hash ^= hash >> (min(8 * Thash_bits, 31));
if ((4 * Thash_bits) < 32) hash ^= hash >> (min(4 * Thash_bits, 31));
if ((2 * Thash_bits) < 32) hash ^= hash >> (min(2 * Thash_bits, 31));
if ((1 * Thash_bits) < 32) hash ^= hash >> (min(1 * Thash_bits, 31));
hash &= (1 << Thash_bits) - 1;
uint32 hash = key.CalcHash();
hash -= (hash >> 17); // hash * 131071 / 131072
hash -= (hash >> 5); // * 31 / 32
hash &= (1 << Thash_bits) - 1; // modulo slots
return hash;
/** static helper - return hash for the given item modulo number of slots */
inline static int CalcHash(const Titem_ &item)
return CalcHash(item.GetKey());
/** item count */
inline int Count() const
return m_num_items;
/** simple clear - forget all items - used by CSegmentCostCacheT.Flush() */
inline void Clear()
for (int i = 0; i < Tcapacity; i++) m_slots[i].Clear();
/** const item search */
const Titem_ *Find(const Tkey &key) const
int hash = CalcHash(key);
const Slot &slot = m_slots[hash];
const Titem_ *item = slot.Find(key);
return item;
/** non-const item search */
Titem_ *Find(const Tkey &key)
Slot &slot = m_slots[hash];
Titem_ *item = slot.Find(key);
/** non-const item search & optional removal (if found) */
Titem_ *TryPop(const Tkey &key)
Titem_ *item = slot.Detach(key);
if (item != NULL) {
m_num_items--;
Status change: