headers/private/package/hpkg/Strings.h

   1 /*
   2  * Copyright 2009-2013, Ingo Weinhold, ingo_weinhold@gmx.de.
   3  * Distributed under the terms of the MIT License.
   4  */
   5 #ifndef _PACKAGE__HPKG__PRIVATE__STRINGS_H_
   6 #define _PACKAGE__HPKG__PRIVATE__STRINGS_H_
   7
   8
   9 #include <new>
  10
  11 #include <util/OpenHashTable.h>
  12
  13
  14 namespace BPackageKit {
  15
  16 namespace BHPKG {
  17
  18 namespace BPrivate {
  19
  20
  21 uint32  hash_string(const char* string);
  22
  23
  24 struct CachedString {
  25         char*                   string;
  26         int32                   index;
  27         uint32                  usageCount;
  28         CachedString*   next;   // hash table link
  29
  30         CachedString()
  31                 :
  32                 string(NULL),
  33                 index(-1),
  34                 usageCount(1)
  35         {
  36         }
  37
  38         ~CachedString()
  39         {
  40                 free(string);
  41         }
  42
  43         bool Init(const char* string)
  44         {
  45                 this->string = strdup(string);
  46                 if (this->string == NULL)
  47                         return false;
  48
  49                 return true;
  50         }
  51 };
  52
  53
  54 struct CachedStringHashDefinition {
  55         typedef const char*             KeyType;
  56         typedef CachedString    ValueType;
  57
  58         size_t HashKey(const char* key) const
  59         {
  60                 return hash_string(key);
  61         }
  62
  63         size_t Hash(const CachedString* value) const
  64         {
  65                 return HashKey(value->string);
  66         }
  67
  68         bool Compare(const char* key, const CachedString* value) const
  69         {
  70                 return strcmp(value->string, key) == 0;
  71         }
  72
  73         CachedString*& GetLink(CachedString* value) const
  74         {
  75                 return value->next;
  76         }
  77 };
  78
  79
  80 typedef BOpenHashTable<CachedStringHashDefinition> CachedStringTable;
  81
  82
  83 struct CachedStringUsageGreater {
  84         bool operator()(const CachedString* a, const CachedString* b)
  85         {
  86                 return a->usageCount > b->usageCount;
  87         }
  88 };
  89
  90
  91 struct StringCache : public CachedStringTable {
  92                                                                 StringCache();
  93                                                                 ~StringCache();
  94
  95                         CachedString*           Get(const char* value);
  96                         void                            Put(CachedString* string);
  97 };
  98
  99
 100 }       // namespace BPrivate
 101
 102 }       // namespace BHPKG
 103
 104 }       // namespace BPackageKit
 105
 106
 107 #endif  // _PACKAGE__HPKG__PRIVATE__STRINGS_H_