haiku/headers/private/userlandfs/shared/HashMap.h

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// HashMap.h
//
// Copyright (c) 2004, Ingo Weinhold (bonefish@cs.tu-berlin.de)
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
// Except as contained in this notice, the name of a copyright holder shall
// not be used in advertising or otherwise to promote the sale, use or other
// dealings in this Software without prior written authorization of the
// copyright holder.
#ifndef HASH_MAP_H
#define HASH_MAP_H
//#include <Debug.h>
#include "AutoLocker.h"
#include "Locker.h"
#include "OpenHashTable.h"
// HashMapElement
template<typename Key, typename Value>
class HashMapElement : public OpenHashElement {
private:
typedef HashMapElement<Key, Value> Element;
public:
HashMapElement() : OpenHashElement(), fKey(), fValue()
{
fNext = -1;
}
inline uint32 Hash() const
{
return fKey.GetHashCode();
}
inline bool operator==(const OpenHashElement &_element) const
{
const Element &element = static_cast<const Element&>(_element);
return (fKey == element.fKey);
}
inline void Adopt(Element &element)
{
fKey = element.fKey;
fValue = element.fValue;
}
Key fKey;
Value fValue;
};
// HashMap
template<typename Key, typename Value>
class HashMap {
public:
class Entry {
public:
Entry() {}
Entry(const Key& key, Value value) : key(key), value(value) {}
Key key;
Value value;
};
class Iterator {
private:
typedef HashMapElement<Key, Value> Element;
public:
Iterator(const Iterator& other)
: fMap(other.fMap),
fIndex(other.fIndex),
fElement(other.fElement),
fLastElement(other.fElement)
{
}
bool HasNext() const
{
return fElement;
}
Entry Next()
{
if (!fElement)
return Entry();
Entry result(fElement->fKey, fElement->fValue);
_FindNext();
return result;
}
Entry Remove()
{
if (!fLastElement)
return Entry();
Entry result(fLastElement->fKey, fLastElement->fValue);
fMap->fTable.Remove(fLastElement, true);
fLastElement = NULL;
return result;
}
Iterator& operator=(const Iterator& other)
{
fMap = other.fMap;
fIndex = other.fIndex;
fElement = other.fElement;
fLastElement = other.fLastElement;
return *this;
}
private:
Iterator(HashMap<Key, Value>* map)
: fMap(map),
fIndex(0),
fElement(NULL),
fLastElement(NULL)
{
// find first
_FindNext();
}
void _FindNext()
{
fLastElement = fElement;
if (fElement && fElement->fNext >= 0) {
fElement = fMap->fTable.ElementAt(fElement->fNext);
return;
}
fElement = NULL;
int32 arraySize = fMap->fTable.ArraySize();
for (; !fElement && fIndex < arraySize; fIndex++)
fElement = fMap->fTable.FindFirst(fIndex);
}
private:
friend class HashMap<Key, Value>;
HashMap<Key, Value>* fMap;
int32 fIndex;
Element* fElement;
Element* fLastElement;
};
HashMap();
~HashMap();
status_t InitCheck() const;
status_t Put(const Key& key, Value value);
Value Remove(const Key& key);
void Clear();
Value Get(const Key& key) const;
bool ContainsKey(const Key& key) const;
int32 Size() const;
Iterator GetIterator();
protected:
typedef HashMapElement<Key, Value> Element;
friend class Iterator;
private:
Element *_FindElement(const Key& key) const;
protected:
OpenHashElementArray<Element> fElementArray;
OpenHashTable<Element, OpenHashElementArray<Element> > fTable;
};
// SynchronizedHashMap
template<typename Key, typename Value>
class SynchronizedHashMap : public Locker {
public:
typedef HashMap<Key, Value>::Entry Entry;
typedef HashMap<Key, Value>::Iterator Iterator;
SynchronizedHashMap() : Locker("synchronized hash map") {}
~SynchronizedHashMap() { Lock(); }
status_t InitCheck() const
{
return fMap.InitCheck();
}
status_t Put(const Key& key, Value value)
{
MapLocker locker(this);
if (!locker.IsLocked())
return B_ERROR;
return fMap.Put(key, value);
}
Value Remove(const Key& key)
{
MapLocker locker(this);
if (!locker.IsLocked())
return Value();
return fMap.Remove(key);
}
void Clear()
{
MapLocker locker(this);
return fMap.Clear();
}
Value Get(const Key& key) const
{
const Locker* lock = this;
MapLocker locker(const_cast<Locker*>(lock));
if (!locker.IsLocked())
return Value();
return fMap.Get(key);
}
bool ContainsKey(const Key& key) const
{
const Locker* lock = this;
MapLocker locker(const_cast<Locker*>(lock));
if (!locker.IsLocked())
return false;
return fMap.ContainsKey(key);
}
int32 Size() const
{
const Locker* lock = this;
MapLocker locker(const_cast<Locker*>(lock));
return fMap.Size();
}
Iterator GetIterator()
{
return fMap.GetIterator();
}
// for debugging only
const HashMap<Key, Value>& GetUnsynchronizedMap() const { return fMap; }
HashMap<Key, Value>& GetUnsynchronizedMap() { return fMap; }
protected:
typedef AutoLocker<Locker> MapLocker;
HashMap<Key, Value> fMap;
};
// HashKey32
template<typename Value>
struct HashKey32 {
HashKey32() {}
HashKey32(const Value& value) : value(value) {}
uint32 GetHashCode() const
{
return (uint32)value;
}
HashKey32<Value> operator=(const HashKey32<Value>& other)
{
value = other.value;
return *this;
}
bool operator==(const HashKey32<Value>& other) const
{
return (value == other.value);
}
bool operator!=(const HashKey32<Value>& other) const
{
return (value != other.value);
}
Value value;
};
// HashKey64
template<typename Value>
struct HashKey64 {
HashKey64() {}
HashKey64(const Value& value) : value(value) {}
uint32 GetHashCode() const
{
uint64 v = (uint64)value;
return (uint32)(v >> 32) ^ (uint32)v;
}
HashKey64<Value> operator=(const HashKey64<Value>& other)
{
value = other.value;
return *this;
}
bool operator==(const HashKey64<Value>& other) const
{
return (value == other.value);
}
bool operator!=(const HashKey64<Value>& other) const
{
return (value != other.value);
}
Value value;
};
// HashMap
// constructor
template<typename Key, typename Value>
HashMap<Key, Value>::HashMap()
: fElementArray(1000),
fTable(1000, &fElementArray)
{
}
// destructor
template<typename Key, typename Value>
HashMap<Key, Value>::~HashMap()
{
}
// InitCheck
template<typename Key, typename Value>
status_t
HashMap<Key, Value>::InitCheck() const
{
return (fTable.InitCheck() && fElementArray.InitCheck()
? B_OK : B_NO_MEMORY);
}
// Put
template<typename Key, typename Value>
status_t
HashMap<Key, Value>::Put(const Key& key, Value value)
{
Element* element = _FindElement(key);
if (element) {
// already contains the key: just set the new value
element->fValue = value;
return B_OK;
}
// does not contain the key yet: add an element
element = fTable.Add(key.GetHashCode());
if (!element)
return B_NO_MEMORY;
element->fKey = key;
element->fValue = value;
return B_OK;
}
// Remove
template<typename Key, typename Value>
Value
HashMap<Key, Value>::Remove(const Key& key)
{
Value value = Value();
if (Element* element = _FindElement(key)) {
value = element->fValue;
fTable.Remove(element);
}
return value;
}
// Clear
template<typename Key, typename Value>
void
HashMap<Key, Value>::Clear()
{
fTable.RemoveAll();
}
// Get
template<typename Key, typename Value>
Value
HashMap<Key, Value>::Get(const Key& key) const
{
if (Element* element = _FindElement(key))
return element->fValue;
return Value();
}
// ContainsKey
template<typename Key, typename Value>
bool
HashMap<Key, Value>::ContainsKey(const Key& key) const
{
return _FindElement(key);
}
// Size
template<typename Key, typename Value>
int32
HashMap<Key, Value>::Size() const
{
return fTable.CountElements();
}
// GetIterator
template<typename Key, typename Value>
HashMap<Key, Value>::Iterator
HashMap<Key, Value>::GetIterator()
{
return Iterator(this);
}
// _FindElement
template<typename Key, typename Value>
HashMap<Key, Value>::Element *
HashMap<Key, Value>::_FindElement(const Key& key) const
{
Element* element = fTable.FindFirst(key.GetHashCode());
while (element && element->fKey != key) {
if (element->fNext >= 0)
element = fTable.ElementAt(element->fNext);
else
element = NULL;
}
return element;
}
#endif // HASH_MAP_H