KVMemoryPool.cpp

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//Created by KVClassFactory on Fri Oct  1 16:50:02 2010
//Author: John Frankland,,,,
 
#include "KVMemoryPool.h"
 
ClassImp(KVMemoryPool)
 
 
 
 
KVMemoryPool::KVMemoryPool(int nchunks, size_t bytes)
{
   // Create nchunks chunks each of size 'bytes'
   fFirst = fLast = fLastChunkUsed = 0;
   for (int i = 0; i < nchunks; i++) {
      KVMemoryChunk* chunk = new KVMemoryChunk(bytes);
      if (!fFirst) fFirst = chunk;
      if (fLast) fLast->SetNext(chunk);
      fLast = chunk;
   }
   fLastChunkUsed = fFirst;
   fChunkSize = bytes;
}
 
 
 
 
void* KVMemoryPool::GetMemory(size_t bytes)
{
   // return pointer to memory of size 'bytes'
   void* p = fFirst->GetMemory(bytes);
   fLastChunkUsed = fFirst;
   if (!p) {
      // search for first available chunk which can provide memory
      do {
         fLastChunkUsed = fLastChunkUsed->Next();
         if (fLastChunkUsed) p = fLastChunkUsed->GetMemory(bytes);
      }
      while (!p && fLastChunkUsed);
   }
   if (!p) {
      // there are no chunks big enough to provide memory
      // add a bigger chunk
      size_t new_chunk = fChunkSize;
      while (new_chunk < bytes) new_chunk *= 2;
      fChunkSize = new_chunk;
      KVMemoryChunk* chunk = new KVMemoryChunk(fChunkSize);
      fLast->SetNext(chunk);
      fLast = chunk;
      fLastChunkUsed = chunk;
      p = fLastChunkUsed->GetMemory(bytes);
   }
   return p;
}
 
 
 
 
KVMemoryPool::~KVMemoryPool()
{
   // Destructor
   KVMemoryChunk* p = fFirst;
   KVMemoryChunk* next;
   while (p) {
      next = p->Next();
      delete p;
      p = next;
   }
}
 
 
 
 
void KVMemoryPool::Print()
{
   KVMemoryChunk* p = fFirst;
   while (p) {
      p->Print();
      p = p->Next();
   }
}