src/common/hashmap.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        hashmap.cpp
   3 // Purpose:     wxHashMap implementation
   4 // Author:      Mattia Barbon
   5 // Modified by:
   6 // Created:     29/01/2002
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Mattia Barbon
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  13 #pragma implementation "hashmap.h"
  14 #endif
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20 #pragma hdrstop
  21 #endif
  22
  23 #include "wx/hashmap.h"
  24
  25 /* FYI: This is the "One-at-a-Time" algorithm by Bob Jenkins */
  26 /* from requirements by Colin Plumb. */
  27 /* (http://burtleburtle.net/bob/hash/doobs.html) */
  28 /* adapted from Perl sources ( hv.h ) */
  29 unsigned long wxStringHash::wxCharStringHash( const wxChar* k )
  30 {
  31     unsigned long hash = 0;
  32
  33     while( *k )
  34     {
  35         hash += *k++;
  36         hash += (hash << 10);
  37         hash ^= (hash >> 6);
  38     }
  39     hash += (hash << 3);
  40     hash ^= (hash >> 11);
  41
  42     return hash + (hash << 15);
  43 }
  44
  45 #if wxUSE_UNICODE
  46 unsigned long wxStringHash::charStringHash( const char* k )
  47 {
  48     unsigned long hash = 0;
  49
  50     while( *k )
  51     {
  52         hash += *k++;
  53         hash += (hash << 10);
  54         hash ^= (hash >> 6);
  55     }
  56     hash += (hash << 3);
  57     hash ^= (hash >> 11);
  58
  59     return hash + (hash << 15);
  60 }
  61 #endif
  62
  63 #if !wxUSE_STL || !defined(HAVE_STL_HASH_MAP)
  64
  65 /* from SGI STL */
  66 const unsigned long _wxHashTableBase2::ms_primes[prime_count] =
  67 {
  68     7ul,          13ul,         29ul,
  69     53ul,         97ul,         193ul,       389ul,       769ul,
  70     1543ul,       3079ul,       6151ul,      12289ul,     24593ul,
  71     49157ul,      98317ul,      196613ul,    393241ul,    786433ul,
  72     1572869ul,    3145739ul,    6291469ul,   12582917ul,  25165843ul,
  73     50331653ul,   100663319ul,  201326611ul, 402653189ul, 805306457ul,
  74     1610612741ul, 3221225473ul, 4294967291ul
  75 };
  76
  77 unsigned long _wxHashTableBase2::GetNextPrime( unsigned long n )
  78 {
  79     const unsigned long* ptr = &ms_primes[0];
  80     for( size_t i = 0; i < prime_count; ++i, ++ptr )
  81     {
  82         if( n < *ptr )
  83             return *ptr;
  84     }
  85
  86     /* someone might try to alloc a 2^32-element hash table */
  87     wxFAIL_MSG( _T("hash table too big?") );
  88
  89     /* quiet warning */
  90     return 0;
  91 }
  92
  93 unsigned long _wxHashTableBase2::GetPreviousPrime( unsigned long n )
  94 {
  95     const unsigned long* ptr = &ms_primes[prime_count - 1];
  96
  97     for( size_t i = 0; i < prime_count; ++i, --ptr )
  98     {
  99         if( n > *ptr )
 100             return *ptr;
 101     }
 102
 103     /* quiet warning */
 104     return 1;
 105 }
 106
 107 void _wxHashTableBase2::DeleteNodes( size_t buckets,
 108                                      _wxHashTable_NodeBase** table,
 109                                      NodeDtor dtor )
 110 {
 111     size_t i;
 112
 113     for( i = 0; i < buckets; ++i )
 114     {
 115         _wxHashTable_NodeBase* node = table[i];
 116         _wxHashTable_NodeBase* tmp;
 117
 118         while( node )
 119         {
 120             tmp = node->m_nxt;
 121             dtor( node );
 122             node = tmp;
 123         }
 124     }
 125
 126     memset( table, 0, buckets * sizeof(void*) );
 127 }
 128
 129 void _wxHashTableBase2::CopyHashTable( _wxHashTable_NodeBase** srcTable,
 130                                        size_t srcBuckets,
 131                                        _wxHashTableBase2* dst,
 132                                        _wxHashTable_NodeBase** dstTable,
 133                                        BucketFromNode func, ProcessNode proc )
 134 {
 135     for( size_t i = 0; i < srcBuckets; ++i )
 136     {
 137         _wxHashTable_NodeBase* nextnode;
 138
 139         for( _wxHashTable_NodeBase* node = srcTable[i]; node; node = nextnode )
 140         {
 141             size_t bucket = func( dst, node );
 142
 143             nextnode = node->m_nxt;
 144             _wxHashTable_NodeBase* newnode = proc( node );
 145             newnode->m_nxt = dstTable[bucket];
 146             dstTable[bucket] = newnode;
 147         }
 148     }
 149 }
 150
 151 _wxHashTable_NodeBase* _wxHashTableBase2::DummyProcessNode(_wxHashTable_NodeBase* node)
 152 {
 153     return node;
 154 }
 155
 156 #endif // !wxUSE_STL || !defined(HAVE_STL_HASH_MAP)