dhewm3-sdk/idlib/containers/HashTable.h
2018-08-20 01:46:21 +02:00

404 lines
8.7 KiB
C++

/*
===========================================================================
Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 GPL Source Code ("Doom 3 Source Code").
Doom 3 Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Doom 3 Source Code is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#ifndef __HASHTABLE_H__
#define __HASHTABLE_H__
/*
===============================================================================
General hash table. Slower than idHashIndex but it can also be used for
linked lists and other data structures than just indexes or arrays.
===============================================================================
*/
template< class Type >
class idHashTable {
public:
idHashTable( int newtablesize = 256 );
idHashTable( const idHashTable<Type> &map );
~idHashTable( void );
// returns total size of allocated memory
size_t Allocated( void ) const;
// returns total size of allocated memory including size of hash table type
size_t Size( void ) const;
void Set( const char *key, Type &value );
bool Get( const char *key, Type **value = NULL ) const;
bool Remove( const char *key );
void Clear( void );
void DeleteContents( void );
// the entire contents can be itterated over, but note that the
// exact index for a given element may change when new elements are added
int Num( void ) const;
Type * GetIndex( int index ) const;
int GetSpread( void ) const;
private:
struct hashnode_s {
idStr key;
Type value;
hashnode_s *next;
hashnode_s( const idStr &k, Type v, hashnode_s *n ) : key( k ), value( v ), next( n ) {};
hashnode_s( const char *k, Type v, hashnode_s *n ) : key( k ), value( v ), next( n ) {};
};
hashnode_s ** heads;
int tablesize;
int numentries;
int tablesizemask;
int GetHash( const char *key ) const;
};
/*
================
idHashTable<Type>::idHashTable
================
*/
template< class Type >
ID_INLINE idHashTable<Type>::idHashTable( int newtablesize ) {
assert( idMath::IsPowerOfTwo( newtablesize ) );
tablesize = newtablesize;
assert( tablesize > 0 );
heads = new hashnode_s *[ tablesize ];
memset( heads, 0, sizeof( *heads ) * tablesize );
numentries = 0;
tablesizemask = tablesize - 1;
}
/*
================
idHashTable<Type>::idHashTable
================
*/
template< class Type >
ID_INLINE idHashTable<Type>::idHashTable( const idHashTable<Type> &map ) {
int i;
hashnode_s *node;
hashnode_s **prev;
assert( map.tablesize > 0 );
tablesize = map.tablesize;
heads = new hashnode_s *[ tablesize ];
numentries = map.numentries;
tablesizemask = map.tablesizemask;
for( i = 0; i < tablesize; i++ ) {
if ( !map.heads[ i ] ) {
heads[ i ] = NULL;
continue;
}
prev = &heads[ i ];
for( node = map.heads[ i ]; node != NULL; node = node->next ) {
*prev = new hashnode_s( node->key, node->value, NULL );
prev = &( *prev )->next;
}
}
}
/*
================
idHashTable<Type>::~idHashTable<Type>
================
*/
template< class Type >
ID_INLINE idHashTable<Type>::~idHashTable( void ) {
Clear();
delete[] heads;
}
/*
================
idHashTable<Type>::Allocated
================
*/
template< class Type >
ID_INLINE size_t idHashTable<Type>::Allocated( void ) const {
return sizeof( heads ) * tablesize + sizeof( *heads ) * numentries;
}
/*
================
idHashTable<Type>::Size
================
*/
template< class Type >
ID_INLINE size_t idHashTable<Type>::Size( void ) const {
return sizeof( idHashTable<Type> ) + sizeof( heads ) * tablesize + sizeof( *heads ) * numentries;
}
/*
================
idHashTable<Type>::GetHash
================
*/
template< class Type >
ID_INLINE int idHashTable<Type>::GetHash( const char *key ) const {
return ( idStr::Hash( key ) & tablesizemask );
}
/*
================
idHashTable<Type>::Set
================
*/
template< class Type >
ID_INLINE void idHashTable<Type>::Set( const char *key, Type &value ) {
hashnode_s *node, **nextPtr;
int hash, s;
hash = GetHash( key );
for( nextPtr = &(heads[hash]), node = *nextPtr; node != NULL; nextPtr = &(node->next), node = *nextPtr ) {
s = node->key.Cmp( key );
if ( s == 0 ) {
node->value = value;
return;
}
if ( s > 0 ) {
break;
}
}
numentries++;
*nextPtr = new hashnode_s( key, value, heads[ hash ] );
(*nextPtr)->next = node;
}
/*
================
idHashTable<Type>::Get
================
*/
template< class Type >
ID_INLINE bool idHashTable<Type>::Get( const char *key, Type **value ) const {
hashnode_s *node;
int hash, s;
hash = GetHash( key );
for( node = heads[ hash ]; node != NULL; node = node->next ) {
s = node->key.Cmp( key );
if ( s == 0 ) {
if ( value ) {
*value = &node->value;
}
return true;
}
if ( s > 0 ) {
break;
}
}
if ( value ) {
*value = NULL;
}
return false;
}
/*
================
idHashTable<Type>::GetIndex
the entire contents can be itterated over, but note that the
exact index for a given element may change when new elements are added
================
*/
template< class Type >
ID_INLINE Type *idHashTable<Type>::GetIndex( int index ) const {
hashnode_s *node;
int count;
int i;
if ( ( index < 0 ) || ( index > numentries ) ) {
assert( 0 );
return NULL;
}
count = 0;
for( i = 0; i < tablesize; i++ ) {
for( node = heads[ i ]; node != NULL; node = node->next ) {
if ( count == index ) {
return &node->value;
}
count++;
}
}
return NULL;
}
/*
================
idHashTable<Type>::Remove
================
*/
template< class Type >
ID_INLINE bool idHashTable<Type>::Remove( const char *key ) {
hashnode_s **head;
hashnode_s *node;
hashnode_s *prev;
int hash;
hash = GetHash( key );
head = &heads[ hash ];
if ( *head ) {
for( prev = NULL, node = *head; node != NULL; prev = node, node = node->next ) {
if ( node->key == key ) {
if ( prev ) {
prev->next = node->next;
} else {
*head = node->next;
}
delete node;
numentries--;
return true;
}
}
}
return false;
}
/*
================
idHashTable<Type>::Clear
================
*/
template< class Type >
ID_INLINE void idHashTable<Type>::Clear( void ) {
int i;
hashnode_s *node;
hashnode_s *next;
for( i = 0; i < tablesize; i++ ) {
next = heads[ i ];
while( next != NULL ) {
node = next;
next = next->next;
delete node;
}
heads[ i ] = NULL;
}
numentries = 0;
}
/*
================
idHashTable<Type>::DeleteContents
================
*/
template< class Type >
ID_INLINE void idHashTable<Type>::DeleteContents( void ) {
int i;
hashnode_s *node;
hashnode_s *next;
for( i = 0; i < tablesize; i++ ) {
next = heads[ i ];
while( next != NULL ) {
node = next;
next = next->next;
delete node->value;
delete node;
}
heads[ i ] = NULL;
}
numentries = 0;
}
/*
================
idHashTable<Type>::Num
================
*/
template< class Type >
ID_INLINE int idHashTable<Type>::Num( void ) const {
return numentries;
}
#if defined(ID_TYPEINFO)
#define __GNUC__ 99
#endif
#if !defined(__GNUC__) || __GNUC__ < 4
/*
================
idHashTable<Type>::GetSpread
================
*/
template< class Type >
int idHashTable<Type>::GetSpread( void ) const {
int i, average, error, e;
hashnode_s *node;
// if no items in hash
if ( !numentries ) {
return 100;
}
average = numentries / tablesize;
error = 0;
for ( i = 0; i < tablesize; i++ ) {
numItems = 0;
for( node = heads[ i ]; node != NULL; node = node->next ) {
numItems++;
}
e = abs( numItems - average );
if ( e > 1 ) {
error += e - 1;
}
}
return 100 - (error * 100 / numentries);
}
#endif
#if defined(ID_TYPEINFO)
#undef __GNUC__
#endif
#endif /* !__HASHTABLE_H__ */