// @(#)root/cont:$Id$
// Author: Fons Rademakers   11/08/95

/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/

//////////////////////////////////////////////////////////////////////////
//                                                                      //
// This class registers all instances of TObject and its derived        //
// classes in a hash table. The Add() and Remove() members are called   //
// from the TObject ctor and dtor, repectively. Using the Print()       //
// member one can see all currently active objects in the system.       //
// Using the resource (in .rootrc): Root.ObjectStat one can toggle this //
// feature on or off.                                                   //
// Using the compile option R__NOSTATS one can de-active this feature   //
// for the entire system (for maximum performance in highly time        //
// critical applications).                                              //
//                                                                      //
// The following output has been produced in a ROOT interactive session
// via the command gObjectTable->Print()
//   class                     cnt    on heap     size    total size    heap size
//   ============================================================================
//   TKey                        4          4       72           288          288
//   TClass                     84         84       80          6720         6720
//   TDataMember               276        276       24          6624         6624
//   TObject                    11         11       12           132          132
//   TMethod                  1974       1974       64        126336       126336
//   TDataType                  34         34       56          1904         1904
//   TList                    2328       2328       36         83808        83808
//   TH1F                        1          1      448           448          448
//   TText                    2688       2688       56        150528       150528
//   TGaxis                      1          0      120           120            0
//   TAxis                       6          3       88           528          264
//   TBox                       57         57       52          2964         2964
//   TLine                     118        118       40          4720         4720
//   TWbox                       1          1       56            56           56
//   TArrow                      1          1       64            64           64
//   TPaveText                  59         59      124          7316         7316
//   TPave                       1          1       92            92           92
//   TFile                       1          1      136           136          136
//   TCanvas                     3          3      444          1332         1332
//   TPad                        1          1      312           312          312
//   TContextMenu                3          3       48           144          144
//   TMethodArg               2166       2166       44         95304        95304
//   TPaveLabel                  1          1      120           120          120
//   THtml                       1          1       32            32           32
//   TROOT                       1          0      208           208            0
//   TApplication                1          1       28            28           28
//   TFileHandler                1          1       20            20           20
//   TColor                    163        163       40          6520         6520
//   TStyle                      1          1      364           364          364
//   TRealData                 117        117       28          3276         3276
//   TBaseClass                 88         88       36          3168         3168
//   THashList                   5          5       40           200          200
//   THashTable                  5          5       36           180          180
//   TGeometry                   1          1       64            64           64
//   TLink                       7          7       60           420          420
//   TPostScript                 1          1      764           764          764
//   TMinuit                     1          1      792           792          792
//   TStopwatch                  1          0       56            56            0
//   TRootGuiFactory             1          1       28            28           28
//   TGX11                       1          1      172           172          172
//   TUnixSystem                 1          1      252           252          252
//   TSignalHandler              1          1       20            20           20
//   TOrdCollection              3          3       40           120          120
//   TEnv                        1          1       24            24           24
//   TCling                      1          1      208           208          208
//   TBenchmark                  1          1       52            52           52
//   TClassTable                 1          1       12            12           12
//   TObjectTable                1          1       12            12           12
//   ----------------------------------------------------------------------------
//   Total:                  10225      10219     5976        506988       506340
//   ============================================================================
//////////////////////////////////////////////////////////////////////////

#include "TObjectTable.h"
#include "TROOT.h"
#include "TClass.h"
#include "TError.h"


TObjectTable *gObjectTable;


ClassImp(TObjectTable)

//______________________________________________________________________________
TObjectTable::TObjectTable(Int_t tableSize)
{
   // Create an object table.

   fSize  = (Int_t)TMath::NextPrime(tableSize);
   fTable = new TObject* [fSize];
   memset(fTable, 0, fSize*sizeof(TObject*));
   fTally = 0;
}

//______________________________________________________________________________
TObjectTable::~TObjectTable()
{
   // Delete TObjectTable.

   delete [] fTable; fTable = 0;
}

//______________________________________________________________________________
void TObjectTable::Print(Option_t *option) const
{
   // Print the object table.
   // If option ="all" prints the list of all objects with the format
   // object number, pointer, class name, object name

   TString opt = option;
   opt.ToLower();
   if (opt.Contains("all")) {
      TObject *obj;
      int i, num = 0;
      Printf("\nList of all objects");
      Printf("object   address            class                    name");
      Printf("================================================================================");
      for (i = 0; i < fSize; i++) {
         if (!fTable[i]) continue;
         num++;
         obj = fTable[i];
         printf("%-8d 0x%-16lx %-24s %s\n", num, (Long_t)obj, obj->ClassName(),
                obj->GetName());
      }
      Printf("================================================================================\n");
   }

   //print the number of instances per class
   InstanceStatistics();
}

//______________________________________________________________________________
void TObjectTable::Add(TObject *op)
{
   // Add an object to the object table.

   if (!op) {
      Error("Add", "op is 0");
      return;
   }
   if (!fTable)
      return;

   Int_t slot = FindElement(op);
   if (fTable[slot] == 0) {
      fTable[slot] = op;
      fTally++;
      if (HighWaterMark())
         Expand(2 * fSize);
   }
}

//______________________________________________________________________________
void TObjectTable::AddObj(TObject *op)
{
   // Add an object to the global object table gObjectTable. If the global
   // table does not exist create it first. This member function may only
   // be used by TObject::TObject. Use Add() to add objects to any other
   // TObjectTable object. This is a static function.

   static Bool_t olock = kFALSE;

   if (!op) {
      ::Error("TObjectTable::AddObj", "op is 0");
      return;
   }
   if (olock)
      return;

   if (!gObjectTable) {
      olock = kTRUE;
      gObjectTable = new TObjectTable(10000);
      olock = kFALSE;
      gObjectTable->Add(gObjectTable);
   }

   gObjectTable->Add(op);
}

//______________________________________________________________________________
void TObjectTable::Delete(Option_t *)
{
   // Delete all objects stored in the TObjectTable.

   for (int i = 0; i < fSize; i++) {
      if (fTable[i]) {
         delete fTable[i];
         fTable[i] = 0;
      }
   }
   fTally = 0;
}

//______________________________________________________________________________
void TObjectTable::Remove(TObject *op)
{
   // Remove an object from the object table.

   if (op == 0) {
      Error("Remove", "remove 0 from TObjectTable");
      return;
   }

   if (!fTable)
      return;

   Int_t i = FindElement(op);
   if (fTable[i] == 0) {
      Warning("Remove", "0x%lx not found at %d", (Long_t)op, i);
      for (int j = 0; j < fSize; j++) {
         if (fTable[j] == op) {
            Error("Remove", "0x%lx found at %d !!!", (Long_t)op, j);
            i = j;
         }
      }
   }

   if (fTable[i]) {
      fTable[i] = 0;
      FixCollisions(i);
      fTally--;
   }
}

//______________________________________________________________________________
void TObjectTable::RemoveQuietly(TObject *op)
{
   // Remove an object from the object table. If op is 0 or not in the table
   // don't complain. Currently only used by the TClonesArray dtor. Should not
   // be used anywhere else, except in places where "special" allocation and
   // de-allocation tricks are performed.

   if (op == 0) return;

   if (!fTable)
      return;

   Int_t i = FindElement(op);
   if (fTable[i] == 0)
      for (int j = 0; j < fSize; j++)
         if (fTable[j] == op)
            i = j;

   fTable[i] = 0;
   FixCollisions(i);
   fTally--;
}

//______________________________________________________________________________
void TObjectTable::Terminate()
{
   // Deletes the object table (this static class function calls the dtor).

   InstanceStatistics();
   delete [] fTable; fTable = 0;
}

//______________________________________________________________________________
Int_t TObjectTable::FindElement(TObject *op)
{
   // Find an object in the object table. Returns the slot where to put
   // the object. To test if the object is actually already in the table
   // use PtrIsValid().

   Int_t    slot, n;
   TObject *slotOp;

   if (!fTable)
      return 0;

   //slot = Int_t(((ULong_t) op >> 2) % fSize);
   slot = Int_t(TString::Hash(&op, sizeof(TObject*)) % fSize);
   for (n = 0; n < fSize; n++) {
      if ((slotOp = fTable[slot]) == 0)
         break;
      if (op == slotOp)
         break;
      if (++slot == fSize)
         slot = 0;
   }
   return slot;
}

//______________________________________________________________________________
void TObjectTable::FixCollisions(Int_t index)
{
   // Rehash the object table in case an object has been removed.

   Int_t oldIndex, nextIndex;
   TObject *nextObject;

   for (oldIndex = index+1; ;oldIndex++) {
      if (oldIndex >= fSize)
         oldIndex = 0;
      nextObject = fTable[oldIndex];
      if (nextObject == 0)
         break;
      nextIndex = FindElement(nextObject);
      if (nextIndex != oldIndex) {
         fTable[nextIndex] = nextObject;
         fTable[oldIndex] = 0;
      }
   }
}

//______________________________________________________________________________
void TObjectTable::Expand(Int_t newSize)
{
   // Expand the object table.

   TObject **oldTable = fTable, *op;
   int oldsize = fSize;
   newSize = (Int_t)TMath::NextPrime(newSize);
   fTable  = new TObject* [newSize];
   memset(fTable, 0, newSize*sizeof(TObject*));
   fSize   = newSize;
   fTally  = 0;
   for (int i = 0; i < oldsize; i++)
      if ((op = oldTable[i]))
         Add(op);
   delete [] oldTable;
}

//______________________________________________________________________________
void TObjectTable::InstanceStatistics() const
{
   // Print the object table.

   int n, h, s, ncum = 0, hcum = 0, scum = 0, tcum = 0, thcum = 0;

   if (fTally == 0 || !fTable)
      return;

   UpdateInstCount();

   Printf("\nObject statistics");
   Printf("class                         cnt    on heap     size    total size    heap size");
   Printf("================================================================================");
   TIter next(gROOT->GetListOfClasses());
   TClass *cl;
   while ((cl = (TClass*) next())) {
      n = cl->GetInstanceCount();
      h = cl->GetHeapInstanceCount();
      s = cl->Size();
      if (n > 0) {
         Printf("%-24s %8d%11d%9d%14d%13d", cl->GetName(), n, h, s, n*s, h*s);
         ncum  += n;
         hcum  += h;
         scum  += s;
         tcum  += n*s;
         thcum += h*s;
      }
   }
   Printf("--------------------------------------------------------------------------------");
   Printf("Total:                   %8d%11d%9d%14d%13d", ncum, hcum, scum, tcum, thcum);
   Printf("================================================================================\n");
}

//______________________________________________________________________________
void TObjectTable::UpdateInstCount() const
{
   // Histogram all objects according to their classes.

   TObject *op;

   if (!fTable || !TROOT::Initialized())
      return;

   gROOT->GetListOfClasses()->R__FOR_EACH(TClass,ResetInstanceCount)();

   for (int i = 0; i < fSize; i++)
      if ((op = fTable[i])) {                // attention: no ==
         if (op->TestBit(TObject::kNotDeleted))
            op->IsA()->AddInstance(op->IsOnHeap());
         else
            Error("UpdateInstCount", "oops 0x%lx\n", (Long_t)op);
      }
}

//______________________________________________________________________________
void *TObjectTable::CheckPtrAndWarn(const char *msg, void *vp)
{
   // Issue a warning in case an object still appears in the table
   // while it should not.

   if (fTable && vp && fTable[FindElement((TObject*)vp)]) {
      Remove((TObject*)vp);
      Warning("CheckPtrAndWarn", "%s (0x%lx)\n", msg, (Long_t)vp);
   }
   return vp;
}