src/apps/webpositive/support/HashKeys.h

   1 /*
   2  * Copyright 2010, Stephan Aßmus <superstippi@gmx.de>. All rights reserved.
   3  * Copyright 2004-2007, Ingo Weinhold <ingo_weinhold@gmx.de>. All rights reserved.
   4  * Distributed under the terms of the MIT License.
   5  */
   6 #ifndef HASH_KEYS_H
   7 #define HASH_KEYS_H
   8
   9 #include <String.h>
  10
  11
  12 namespace BPrivate {
  13
  14 #if 0
  15 // TODO: Move here from HashMap.h and adapt all clients.
  16 // HashKey32
  17 template<typename Value>
  18 struct HashKey32 {
  19         HashKey32() {}
  20         HashKey32(const Value& value) : value(value) {}
  21
  22         uint32 GetHashCode() const
  23         {
  24                 return (uint32)value;
  25         }
  26
  27         HashKey32<Value> operator=(const HashKey32<Value>& other)
  28         {
  29                 value = other.value;
  30                 return *this;
  31         }
  32
  33         bool operator==(const HashKey32<Value>& other) const
  34         {
  35                 return (value == other.value);
  36         }
  37
  38         bool operator!=(const HashKey32<Value>& other) const
  39         {
  40                 return (value != other.value);
  41         }
  42
  43         Value   value;
  44 };
  45
  46
  47 // HashKey64
  48 template<typename Value>
  49 struct HashKey64 {
  50         HashKey64() {}
  51         HashKey64(const Value& value) : value(value) {}
  52
  53         uint32 GetHashCode() const
  54         {
  55                 uint64 v = (uint64)value;
  56                 return (uint32)(v >> 32) ^ (uint32)v;
  57         }
  58
  59         HashKey64<Value> operator=(const HashKey64<Value>& other)
  60         {
  61                 value = other.value;
  62                 return *this;
  63         }
  64
  65         bool operator==(const HashKey64<Value>& other) const
  66         {
  67                 return (value == other.value);
  68         }
  69
  70         bool operator!=(const HashKey64<Value>& other) const
  71         {
  72                 return (value != other.value);
  73         }
  74
  75         Value   value;
  76 };
  77 #endif
  78
  79
  80 struct HashKeyString {
  81         HashKeyString() {}
  82         HashKeyString(const BString& value) : value(value) {}
  83         HashKeyString(const char* string) : value(string) {}
  84
  85         uint32 GetHashCode() const
  86         {
  87                 // from the Dragon Book: a slightly modified hashpjw()
  88                 uint32 hash = 0;
  89                 const char* string = value.String();
  90                 if (string != NULL) {
  91                         for (; *string; string++) {
  92                                 uint32 g = hash & 0xf0000000;
  93                                 if (g != 0)
  94                                         hash ^= g >> 24;
  95                                 hash = (hash << 4) + *string;
  96                         }
  97                 }
  98                 return hash;
  99         }
 100
 101         HashKeyString operator=(const HashKeyString& other)
 102         {
 103                 value = other.value;
 104                 return *this;
 105         }
 106
 107         bool operator==(const HashKeyString& other) const
 108         {
 109                 return (value == other.value);
 110         }
 111
 112         bool operator!=(const HashKeyString& other) const
 113         {
 114                 return (value != other.value);
 115         }
 116
 117         BString value;
 118 };
 119
 120 }       // namespace BPrivate
 121
 122 using BPrivate::HashKeyString;
 123
 124 #endif  // HASH_KEYS_H