wxWidgets/include/wx/hashmap.h
2002-09-12 20:15:51 +00:00

550 lines
18 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: hashmap.h
// Purpose: wxHashMap class
// Author: Mattia Barbon
// Modified by:
// Created: 29/01/2002
// RCS-ID: $Id$
// Copyright: (c) Mattia Barbon
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_HASHMAP_H_
#define _WX_HASHMAP_H_
#if defined(__GNUG__) && !defined(__APPLE__)
#pragma interface "hashmap.h"
#endif
#include "wx/string.h"
// private
struct WXDLLEXPORT _wxHashTable_NodeBase
{
_wxHashTable_NodeBase() : m_nxt(0) {}
_wxHashTable_NodeBase* m_nxt;
};
// private
class WXDLLEXPORT _wxHashTableBase2
{
public:
typedef void (*NodeDtor)(_wxHashTable_NodeBase*);
typedef unsigned long (*BucketFromNode)(_wxHashTableBase2*,_wxHashTable_NodeBase*);
typedef _wxHashTable_NodeBase* (*ProcessNode)(_wxHashTable_NodeBase*);
protected:
static _wxHashTable_NodeBase* DummyProcessNode(_wxHashTable_NodeBase* node);
static void DeleteNodes( size_t buckets, _wxHashTable_NodeBase** table,
NodeDtor dtor );
static _wxHashTable_NodeBase* GetFirstNode( size_t buckets,
_wxHashTable_NodeBase** table )
{
for( size_t i = 0; i < buckets; ++i )
if( table[i] )
return table[i];
return 0;
}
// as static const unsigned prime_count = 31 but works with all compilers
enum { prime_count = 31 };
static const unsigned long ms_primes[prime_count];
// returns the first prime in ms_primes greater than n
static unsigned long GetNextPrime( unsigned long n );
// returns the first prime in ms_primes smaller than n
// ( or ms_primes[0] if n is very small )
static unsigned long GetPreviousPrime( unsigned long n );
static void CopyHashTable( _wxHashTable_NodeBase** srcTable,
size_t srcBuckets, _wxHashTableBase2* dst,
_wxHashTable_NodeBase** dstTable,
BucketFromNode func, ProcessNode proc );
static void** AllocTable( size_t size )
{
return (void **)calloc(size, sizeof(void*));
}
};
#define _WX_DECLARE_HASHTABLE( VALUE_T, KEY_T, HASH_T, KEY_EX_T, KEY_EQ_T, CLASSNAME, CLASSEXP, SHOULD_GROW, SHOULD_SHRINK ) \
CLASSEXP CLASSNAME : protected _wxHashTableBase2 \
{ \
public: \
typedef KEY_T key_type; \
typedef VALUE_T value_type; \
typedef HASH_T hasher; \
typedef KEY_EQ_T key_equal; \
\
typedef size_t size_type; \
typedef ptrdiff_t difference_type; \
typedef value_type* pointer; \
typedef const value_type* const_pointer; \
typedef value_type& reference; \
typedef const value_type& const_reference; \
/* should these be protected? */ \
typedef const KEY_T const_key_type; \
typedef const VALUE_T const_mapped_type; \
public: \
struct Node; \
typedef KEY_EX_T key_extractor; \
typedef CLASSNAME Self; \
protected: \
Node** m_table; \
size_t m_tableBuckets; \
size_t m_items; \
hasher m_hasher; \
key_equal m_equals; \
key_extractor m_getKey; \
public: \
struct Node:public _wxHashTable_NodeBase \
{ \
public: \
Node( const value_type& value ) \
: m_value( value ) {} \
Node* m_next() { return (Node*)this->m_nxt; } \
\
value_type m_value; \
}; \
\
struct Iterator; \
friend struct Iterator; \
protected: \
static void DeleteNode( _wxHashTable_NodeBase* node ) \
{ \
delete (Node*)node; \
} \
public: \
/* */ \
/* forward iterator */ \
/* */ \
struct Iterator \
{ \
Node* m_node; \
Self* m_ht; \
\
Iterator() : m_node(0), m_ht(0) {} \
Iterator( Node* node, const Self* ht ) \
: m_node(node), m_ht((Self*)ht) {} \
bool operator ==( const Iterator& it ) const \
{ return m_node == it.m_node; } \
bool operator !=( const Iterator& it ) const \
{ return m_node != it.m_node; } \
protected: \
Node* GetNextNode() \
{ \
size_type bucket = GetBucketForNode(m_ht,m_node); \
for( size_type i = bucket + 1; i < m_ht->m_tableBuckets; ++i ) \
{ \
if( m_ht->m_table[i] ) \
return m_ht->m_table[i]; \
} \
return 0; \
} \
\
void PlusPlus() \
{ \
Node* next = m_node->m_next(); \
m_node = next ? next : GetNextNode(); \
} \
}; \
\
public: \
struct iterator:public Iterator \
{ \
iterator() : Iterator() {} \
iterator( Node* node, Self* ht ) : Iterator( node, ht ) {} \
iterator& operator++() { PlusPlus(); return *this; } \
iterator operator++(int) { iterator it=*this;PlusPlus();return it; } \
reference operator *() const { return m_node->m_value; } \
pointer operator ->() const { return &(m_node->m_value); } \
}; \
\
struct const_iterator:public Iterator \
{ \
const_iterator() : Iterator() {} \
const_iterator( Node* node, const Self* ht ) \
: Iterator( node, (Self*)ht ) {} \
const_iterator& operator++() { PlusPlus();return *this; } \
const_iterator operator++(int) { const_iterator it=*this;PlusPlus();return it; } \
const_reference operator *() const { return m_node->m_value; } \
const_pointer operator ->() const { return &(m_node->m_value); } \
}; \
\
CLASSNAME( size_type size = 10, const hasher& hfun = hasher(), \
const key_equal& k_eq = key_equal(), \
const key_extractor& k_ex = key_extractor() ) \
: m_tableBuckets( GetNextPrime( size ) ), \
m_items( 0 ), \
m_hasher( hfun ), \
m_equals( k_eq ), \
m_getKey( k_ex ) \
{ \
m_table = (Node**)AllocTable( m_tableBuckets ); \
} \
\
CLASSNAME( const Self& ht ) \
: m_table( 0 ), \
m_tableBuckets( 0 ), \
m_items( ht.m_items ), \
m_hasher( ht.m_hasher ), \
m_equals( ht.m_equals ), \
m_getKey( ht.m_getKey ) \
{ \
HashCopy( ht ); \
} \
\
const Self& operator=( const Self& ht ) \
{ \
clear(); \
m_hasher = ht.m_hasher; \
m_equals = ht.m_equals; \
m_getKey = ht.m_getKey; \
m_items = ht.m_items; \
HashCopy( ht ); \
return *this; \
} \
\
~CLASSNAME() \
{ \
clear(); \
\
free(m_table); \
} \
\
hasher hash_funct() { return m_hasher; } \
key_equal key_eq() { return m_equals; } \
\
/* removes all elements from the hash table, but does not */ \
/* shrink it ( perhaps it should ) */ \
void clear() { DeleteNodes( m_tableBuckets, (_wxHashTable_NodeBase**)m_table, DeleteNode ); } \
\
size_type size() const { return m_items; } \
size_type max_size() const { return size_type(-1); } \
bool empty() const { return size() == 0; } \
\
const_iterator end() const { return const_iterator( 0, this ); } \
iterator end() { return iterator( 0, this ); } \
const_iterator begin() const \
{ return const_iterator( (Node*)GetFirstNode( m_tableBuckets, (_wxHashTable_NodeBase**)m_table ), this ); }; \
iterator begin() \
{ return iterator( (Node*)GetFirstNode( m_tableBuckets, (_wxHashTable_NodeBase**)m_table ), this ); }; \
\
size_type erase( const const_key_type& key ) \
{ \
Node** node = GetNodePtr( key ); \
\
if( !node ) \
return 0; \
\
--m_items; \
Node* temp = (*node)->m_next(); \
delete *node; \
(*node) = temp; \
if( SHOULD_SHRINK( m_tableBuckets, m_items ) ) \
ResizeTable( GetPreviousPrime( m_tableBuckets ) - 1 ); \
return 1; \
} \
\
protected: \
static size_type GetBucketForNode( Self* ht, Node* node ) \
{ \
return ht->m_hasher( ht->m_getKey( node->m_value ) ) \
% ht->m_tableBuckets; \
} \
static Node* CopyNode( Node* node ) { return new Node( *node ); } \
\
Node* GetOrCreateNode( const value_type& value ) \
{ \
const const_key_type& key = m_getKey( value ); \
size_t bucket = m_hasher( key ) % m_tableBuckets; \
Node* node = m_table[bucket]; \
\
while( node ) \
{ \
if( m_equals( m_getKey( node->m_value ), key ) ) \
return node; \
node = node->m_next(); \
} \
\
node = new Node( value ); \
node->m_nxt = m_table[bucket]; \
m_table[bucket] = node; \
\
/* must be after the node is inserted */ \
++m_items; \
if( SHOULD_GROW( m_tableBuckets, m_items ) ) \
ResizeTable( m_tableBuckets ); \
\
return node; \
} \
\
/* returns NULL if not found */ \
Node** GetNodePtr( const const_key_type& key ) const \
{ \
unsigned long hash = m_hasher( key ); \
Node** node = &m_table[hash % m_tableBuckets]; \
\
while( *node ) \
{ \
if( m_equals( m_getKey( (*node)->m_value ), key ) ) \
return node; \
node = (Node**)&(*node)->m_nxt; \
} \
\
return 0; \
} \
\
/* returns NULL if not found */ \
/* expressing it in terms of GetNodePtr is 5-8% slower :-( */ \
Node* GetNode( const const_key_type& key ) const \
{ \
unsigned long hash = m_hasher( key ); \
Node* node = m_table[hash % m_tableBuckets]; \
\
while( node ) \
{ \
if( m_equals( m_getKey( node->m_value ), key ) ) \
return node; \
node = node->m_next(); \
} \
\
return 0; \
} \
\
void ResizeTable( size_t newSize ) \
{ \
newSize = GetNextPrime( newSize ); \
Node** srcTable = m_table; \
size_t srcBuckets = m_tableBuckets; \
m_table = (Node**)AllocTable( newSize ); \
m_tableBuckets = newSize; \
\
CopyHashTable( (_wxHashTable_NodeBase**)srcTable, srcBuckets, \
this, (_wxHashTable_NodeBase**)m_table, \
(BucketFromNode)&GetBucketForNode,\
(ProcessNode)&DummyProcessNode ); \
free(srcTable); \
} \
\
/* this must be called _after_ m_table has been cleaned */ \
void HashCopy( const Self& ht ) \
{ \
ResizeTable( ht.size() ); \
CopyHashTable( (_wxHashTable_NodeBase**)ht.m_table, ht.m_tableBuckets,\
(_wxHashTableBase2*)this, \
(_wxHashTable_NodeBase**)m_table, \
(BucketFromNode)&GetBucketForNode, \
(ProcessNode)&CopyNode ); \
} \
};
// defines an STL-like pair class CLASSNAME storing two fields: first of type
// KEY_T and second of type VALUE_T
#define _WX_DECLARE_PAIR( KEY_T, VALUE_T, CLASSNAME, CLASSEXP ) \
CLASSEXP CLASSNAME \
{ \
public: \
typedef KEY_T t1; \
typedef VALUE_T t2; \
typedef const KEY_T const_t1; \
typedef const VALUE_T const_t2; \
\
CLASSNAME( const const_t1& f, const const_t2& s ):first(t1(f)),second(t2(s)) {} \
CLASSNAME( const const_t1& f ):first(t1(f)),second(t2()) {} \
\
t1 first; \
t2 second; \
};
// defines the class CLASSNAME returning the key part (of type KEY_T) from a
// pair of type PAIR_T
#define _WX_DECLARE_HASH_MAP_KEY_EX( KEY_T, PAIR_T, CLASSNAME, CLASSEXP ) \
CLASSEXP CLASSNAME \
{ \
typedef KEY_T key_type; \
typedef PAIR_T pair_type; \
typedef const key_type const_key_type; \
typedef const pair_type const_pair_type; \
typedef const_key_type& const_key_reference; \
typedef const_pair_type& const_pair_reference; \
public: \
CLASSNAME() { } \
const_key_reference operator()( const_pair_reference pair ) const { return pair.first; }\
\
/* the dummy assignment operator is needed to suppress compiler */ \
/* warnings from hash table class' operator=(): gcc complains about */ \
/* "statement with no effect" without it */ \
CLASSNAME& operator=(const CLASSNAME&) { return *this; } \
};
// grow/shrink predicates
inline bool never_grow( size_t, size_t ) { return FALSE; }
inline bool never_shrink( size_t, size_t ) { return FALSE; }
inline bool grow_lf70( size_t buckets, size_t items )
{
return float(items)/float(buckets) >= 0.85;
}
// ----------------------------------------------------------------------------
// hashing and comparison functors
// ----------------------------------------------------------------------------
// NB: implementation detail: all of these classes must have dummy assignment
// operators to suppress warnings about "statement with no effect" from gcc
// in the hash table class assignment operator (where they're assigned)
// integer types
class WXDLLEXPORT wxIntegerHash
{
public:
wxIntegerHash() { }
unsigned long operator()( long x ) const { return (unsigned long)x; }
unsigned long operator()( unsigned long x ) const { return x; }
unsigned long operator()( int x ) const { return (unsigned long)x; }
unsigned long operator()( unsigned int x ) const { return x; }
unsigned long operator()( short x ) const { return (unsigned long)x; }
unsigned long operator()( unsigned short x ) const { return x; }
wxIntegerHash& operator=(const wxIntegerHash&) { return *this; }
};
class WXDLLEXPORT wxIntegerEqual
{
public:
wxIntegerEqual() { }
bool operator()( long a, long b ) const { return a == b; }
bool operator()( unsigned long a, unsigned long b ) const { return a == b; }
bool operator()( int a, int b ) const { return a == b; }
bool operator()( unsigned int a, unsigned int b ) const { return a == b; }
bool operator()( short a, short b ) const { return a == b; }
bool operator()( unsigned short a, unsigned short b ) const { return a == b; }
wxIntegerEqual& operator=(const wxIntegerEqual&) { return *this; }
};
// pointers
class WXDLLEXPORT wxPointerHash
{
public:
wxPointerHash() { }
// TODO: this might not work well on architectures with 64 bit pointers but
// 32 bit longs, we should use % ULONG_MAX there
unsigned long operator()( const void* k ) const { return (unsigned long)k; }
wxPointerHash& operator=(const wxPointerHash&) { return *this; }
};
class WXDLLEXPORT wxPointerEqual
{
public:
wxPointerEqual() { }
bool operator()( const void* a, const void* b ) const { return a == b; }
wxPointerEqual& operator=(const wxPointerEqual&) { return *this; }
};
// wxString, char*, wxChar*
class WXDLLEXPORT wxStringHash
{
public:
wxStringHash() {}
unsigned long operator()( const wxString& x ) const
{ return wxCharStringHash( x.c_str() ); }
unsigned long operator()( const wxChar* x ) const
{ return wxCharStringHash( x ); }
static unsigned long wxCharStringHash( const wxChar* );
#if wxUSE_UNICODE
unsigned long operator()( const char* x ) const
{ return charStringHash( x ); }
static unsigned long charStringHash( const char* );
#endif // wxUSE_UNICODE
wxStringHash& operator=(const wxStringHash&) { return *this; }
};
class WXDLLEXPORT wxStringEqual
{
public:
wxStringEqual() {}
bool operator()( const wxString& a, const wxString& b ) const
{ return a == b; }
bool operator()( const wxChar* a, const wxChar* b ) const
{ return wxStrcmp( a, b ) == 0; }
#if wxUSE_UNICODE
bool operator()( const char* a, const char* b ) const
{ return strcmp( a, b ) == 0; }
#endif // wxUSE_UNICODE
wxStringEqual& operator=(const wxStringEqual&) { return *this; }
};
#define _WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, CLASSEXP ) \
_WX_DECLARE_PAIR( KEY_T, VALUE_T, CLASSNAME##_wxImplementation_Pair, CLASSEXP ) \
_WX_DECLARE_HASH_MAP_KEY_EX( KEY_T, CLASSNAME##_wxImplementation_Pair, CLASSNAME##_wxImplementation_KeyEx, CLASSEXP ) \
_WX_DECLARE_HASHTABLE( CLASSNAME##_wxImplementation_Pair, KEY_T, HASH_T, CLASSNAME##_wxImplementation_KeyEx, KEY_EQ_T, CLASSNAME##_wxImplementation_HashTable, CLASSEXP, grow_lf70, never_shrink ) \
CLASSEXP CLASSNAME:public CLASSNAME##_wxImplementation_HashTable \
{ \
public: \
typedef VALUE_T mapped_type; \
\
CLASSNAME( size_type hint = 100, hasher hf = hasher(), key_equal eq = key_equal() ) \
: CLASSNAME##_wxImplementation_HashTable( hint, hf, eq, CLASSNAME##_wxImplementation_KeyEx() ) {} \
\
mapped_type& operator[]( const const_key_type& key ) \
{ \
return GetOrCreateNode( CLASSNAME##_wxImplementation_Pair( key ) )->m_value.second; \
} \
\
const_iterator find( const const_key_type& key ) const \
{ \
return const_iterator( GetNode( key ), this ); \
} \
\
iterator find( const const_key_type& key ) \
{ \
return iterator( GetNode( key ), this ); \
} \
\
void insert( const value_type& v ) { (*this)[v.first] = v.second; } \
\
size_type erase( const key_type& k ) \
{ return CLASSNAME##_wxImplementation_HashTable::erase( k ); } \
void erase( const iterator& it ) { erase( it->first ); } \
void erase( const const_iterator& it ) { erase( it->first ); } \
\
/* count() == 0 | 1 */ \
size_type count( const const_key_type& key ) \
{ return GetNode( key ) ? 1 : 0; } \
};
// these macros are to be used in the user code
#define WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME) \
_WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, class )
#define WX_DECLARE_STRING_HASH_MAP( VALUE_T, CLASSNAME ) \
_WX_DECLARE_HASH_MAP( wxString, VALUE_T, wxStringHash, wxStringEqual, \
CLASSNAME, class );
#define WX_DECLARE_VOIDPTR_HASH_MAP( VALUE_T, CLASSNAME ) \
_WX_DECLARE_HASH_MAP( void*, VALUE_T, wxPointerHash, wxPointerEqual, \
CLASSNAME, class );
// and these do exactly the same thing but should be used inside the
// library
#define WX_DECLARE_EXPORTED_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME) \
_WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, class WXDLLEXPORT )
#define WX_DECLARE_EXPORTED_STRING_HASH_MAP( VALUE_T, CLASSNAME ) \
_WX_DECLARE_HASH_MAP( wxString, VALUE_T, wxStringHash, wxStringEqual, \
CLASSNAME, class WXDLLEXPORT );
#define WX_DECLARE_EXPORTED_VOIDPTR_HASH_MAP( VALUE_T, CLASSNAME ) \
_WX_DECLARE_HASH_MAP( void*, VALUE_T, wxPointerHash, wxPointerEqual, \
CLASSNAME, class WXDLLEXPORT );
#endif // _WX_HASHMAP_H_