WDL/stringpool.h

   1 #ifndef _WDL_STRINGPOOL_H_
   2 #define _WDL_STRINGPOOL_H_
   3
   4
   5 #include "wdlstring.h"
   6 #include "assocarray.h"
   7 #include "mutex.h"
   8
   9 class WDL_StringPool
  10 {
  11   friend class WDL_PooledString;
  12 public:
  13   WDL_StringPool(bool wantMutex) : m_strings(true) { m_mutex = wantMutex ? new WDL_Mutex : NULL; };
  14   ~WDL_StringPool() { delete m_mutex; }
  15
  16 private:
  17   WDL_StringKeyedArray<int> m_strings;
  18 protected:
  19   WDL_Mutex *m_mutex;
  20
  21 };
  22
  23 class WDL_PooledString
  24 {
  25 public:
  26   WDL_PooledString(WDL_StringPool *pool, const char *value=NULL) { m_pool = pool; m_val = ""; Set(value); }
  27   ~WDL_PooledString() { Set(""); }
  28
  29   const char *Get() { return m_val; }
  30
  31   void Set(const char *value)
  32   {
  33     if (!value) value="";
  34     if (strcmp(value,m_val))
  35     {
  36       WDL_MutexLock(m_pool->m_mutex); // may or may not actually be a mutex
  37
  38       const char *oldval = m_val;
  39
  40       if (*value)
  41       {
  42         // set to new value
  43         const char *keyptr=NULL;
  44         int * ref = m_pool->m_strings.GetPtr(value,&keyptr);
  45         if (ref)
  46         {
  47           ++*ref;
  48           m_val=keyptr;
  49         }
  50         else m_pool->m_strings.Insert(value,1,&m_val);
  51       }
  52       else m_val="";
  53
  54       if (oldval[0])
  55       {
  56         int *oldref = m_pool->m_strings.GetPtr(oldval);
  57         if (oldref && --*oldref<=0) m_pool->m_strings.Delete(oldval);
  58       }
  59     }
  60   }
  61
  62   // utility for compat with WDL_String
  63   void Append(const char *value)
  64   {
  65     if (value&&*value)
  66     {
  67       WDL_String tmp(Get());
  68       tmp.Append(value);
  69       Set(tmp.Get());
  70     }
  71   }
  72   void Insert(const char *value, int pos)
  73   {
  74     WDL_String tmp(Get());
  75     tmp.Insert(value,pos);
  76     Set(tmp.Get());
  77   }
  78   void DeleteSub(int pos, int len)
  79   {
  80     WDL_String tmp(Get());
  81     tmp.DeleteSub(pos,len);
  82     Set(tmp.Get());
  83   }
  84
  85 private:
  86   const char *m_val;
  87   WDL_StringPool *m_pool;
  88
  89 };
  90
  91
  92 #endif _WDL_STRINGPOOL_H_