wxWidgets/include/wx/hash.h
2000-02-25 19:23:11 +00:00

225 lines
9.4 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: wx/hash.h
// Purpose: wxHashTable class
// Author: Julian Smart
// Modified by: VZ at 25.02.00: type safe hashes with WX_DECLARE_HASH()
// Created: 01/02/97
// RCS-ID: $Id$
// Copyright: (c)
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_HASH_H__
#define _WX_HASH_H__
#ifdef __GNUG__
#pragma interface "hash.h"
#endif
#include "wx/list.h"
// the default size of the hash
#define wxHASH_SIZE_DEFAULT (1000)
/*
* A hash table is an array of user-definable size with lists
* of data items hanging off the array positions. Usually there'll
* be a hit, so no search is required; otherwise we'll have to run down
* the list to find the desired item.
*/
// ----------------------------------------------------------------------------
// this is the base class for object hashes: hash tables which contain
// pointers to objects
// ----------------------------------------------------------------------------
class WXDLLEXPORT wxHashTableBase : public wxObject
{
public:
wxHashTableBase();
void Create(wxKeyType keyType = wxKEY_INTEGER,
size_t size = wxHASH_SIZE_DEFAULT);
void Destroy();
size_t GetSize() const { return m_hashSize; }
size_t GetCount() const { return m_count; }
void DeleteContents(bool flag);
protected:
// find the node for (key, value)
wxNodeBase *GetNode(long key, long value) const;
// the array of lists in which we store the values for given key hash
wxListBase **m_hashTable;
// the size of m_lists array
size_t m_hashSize;
// the type of indexing we use
wxKeyType m_keyType;
// the total number of elements in the hash
size_t m_count;
// should we delete our data?
bool m_deleteContents;
private:
// no copy ctor/assignment operator (yet)
DECLARE_NO_COPY_CLASS(wxHashTableBase);
};
// ----------------------------------------------------------------------------
// for compatibility only
// ----------------------------------------------------------------------------
class WXDLLEXPORT wxHashTable : public wxObject
{
public:
int n;
int current_position;
wxNode *current_node;
unsigned int key_type;
wxList **hash_table;
wxHashTable(int the_key_type = wxKEY_INTEGER,
int size = wxHASH_SIZE_DEFAULT);
~wxHashTable();
// copy ctor and assignment operator
wxHashTable(const wxHashTable& table) { DoCopy(table); }
wxHashTable& operator=(const wxHashTable& table)
{ Clear(); DoCopy(table); return *this; }
void DoCopy(const wxHashTable& table);
void Destroy();
bool Create(int the_key_type = wxKEY_INTEGER,
int size = wxHASH_SIZE_DEFAULT);
// Note that there are 2 forms of Put, Get.
// With a key and a value, the *value* will be checked
// when a collision is detected. Otherwise, if there are
// 2 items with a different value but the same key,
// we'll retrieve the WRONG ONE. So where possible,
// supply the required value along with the key.
// In fact, the value-only versions make a key, and still store
// the value. The use of an explicit key might be required
// e.g. when combining several values into one key.
// When doing that, it's highly likely we'll get a collision,
// e.g. 1 + 2 = 3, 2 + 1 = 3.
// key and value are NOT necessarily the same
void Put(long key, long value, wxObject *object);
void Put(long key, const wxChar *value, wxObject *object);
// key and value are the same
void Put(long value, wxObject *object);
void Put(const wxChar *value, wxObject *object);
// key and value not the same
wxObject *Get(long key, long value) const;
wxObject *Get(long key, const wxChar *value) const;
// key and value are the same
wxObject *Get(long value) const;
wxObject *Get(const wxChar *value) const;
// Deletes entry and returns data if found
wxObject *Delete(long key);
wxObject *Delete(const wxChar *key);
wxObject *Delete(long key, int value);
wxObject *Delete(long key, const wxChar *value);
// Construct your own integer key from a string, e.g. in case
// you need to combine it with something
long MakeKey(const wxChar *string) const;
// Way of iterating through whole hash table (e.g. to delete everything)
// Not necessary, of course, if you're only storing pointers to
// objects maintained separately
void BeginFind();
wxNode *Next();
void DeleteContents(bool flag);
void Clear();
// Returns number of nodes
size_t GetCount() const { return m_count; }
private:
size_t m_count; // number of elements in the hashtable
bool m_deleteContents;
DECLARE_DYNAMIC_CLASS(wxHashTable)
};
// defines a new type safe hash table which stores the elements of type eltype
// in lists of class listclass
#define WX_DECLARE_HASH(eltype, listclass, hashclass) \
class WXDLLEXPORT hashclass : public wxHashTableBase \
{ \
public: \
hashclass(wxKeyType keyType = wxKEY_INTEGER, \
size_t size = wxHASH_SIZE_DEFAULT) \
{ Create(keyType, size); } \
\
~hashclass() { Destroy(); } \
\
void Put(long key, long val, eltype *data) { DoPut(key, val, data); } \
void Put(long key, eltype *data) { DoPut(key, key, data); } \
\
eltype *Get(long key, long value) const \
{ \
wxNodeBase *node = GetNode(key, value); \
return node ? ((listclass::Node *)node)->GetData() : (eltype *)0; \
} \
eltype *Get(long key) const { return Get(key, key); } \
\
eltype *Delete(long key, long value) \
{ \
eltype *data; \
\
wxNodeBase *node = GetNode(key, value); \
if ( node ) \
{ \
data = ((listclass::Node *)node)->GetData(); \
\
delete node; \
m_count--; \
} \
else \
{ \
data = (eltype *)0; \
} \
\
return data; \
} \
eltype *Delete(long key) { return Delete(key, key); } \
\
protected: \
void DoPut(long key, long value, eltype *data) \
{ \
size_t slot = (size_t)abs(key % m_hashSize); \
\
if ( !m_hashTable[slot] ) \
{ \
m_hashTable[slot] = new listclass(m_keyType); \
if ( m_deleteContents ) \
m_hashTable[slot]->DeleteContents(TRUE); \
} \
\
((listclass *)m_hashTable[slot])->Append(value, data); \
m_count++; \
} \
}
#endif
// _WX_HASH_H__