TLeaf.cxx

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// @(#)root/tree:$Id: TLeaf.cxx 36388 2010-10-21 04:05:14Z pcanal $
// Author: Rene Brun   12/01/96

/*************************************************************************
 * 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.             *
 *************************************************************************/

//////////////////////////////////////////////////////////////////////////
//                                                                      //
// A TLeaf describes individual elements of a TBranch                   //
//       See TBranch structure in TTree.                                //
//////////////////////////////////////////////////////////////////////////

#include "TLeaf.h"
#include "TBranch.h"
#include "TTree.h"
#include "TVirtualPad.h"
#include "TBrowser.h"
#include "TClass.h"

#include <ctype.h>

R__EXTERN TTree* gTree;

ClassImp(TLeaf)

//______________________________________________________________________________
TLeaf::TLeaf()
   : TNamed()
   , fNdata(0)
   , fLen(0)
   , fLenType(0)
   , fOffset(0)
   , fIsRange(kFALSE)
   , fIsUnsigned(kFALSE)
   , fLeafCount(0)
   , fBranch(0)
{
}

//______________________________________________________________________________
TLeaf::TLeaf(TBranch *parent, const char* name, const char *)
   : TNamed(name, name)
   , fNdata(0)
   , fLen(0)
   , fLenType(4)
   , fOffset(0)
   , fIsRange(kFALSE)
   , fIsUnsigned(kFALSE)
   , fLeafCount(0)
   , fBranch(parent)
{
   // Create a Leaf.
   //
   // See the TTree and TBranch constructors for explanation of parameters.

   fLeafCount = GetLeafCounter(fLen);

   if (fLen == -1) {
      MakeZombie(); 
      return;
   }

   const char *bracket = strchr(name, '[');
   if (bracket) fName.ReplaceAll(bracket,"");
}

//______________________________________________________________________________
TLeaf::TLeaf(const TLeaf& lf) : 
  TNamed(lf),
  fNdata(lf.fNdata),
  fLen(lf.fLen),
  fLenType(lf.fLenType),
  fOffset(lf.fOffset),
  fIsRange(lf.fIsRange),
  fIsUnsigned(lf.fIsUnsigned),
  fLeafCount(lf.fLeafCount),
  fBranch(lf.fBranch)
{ 
   //copy constructor
}

//______________________________________________________________________________
TLeaf& TLeaf::operator=(const TLeaf& lf) 
{
   //assignement operator
   if(this!=&lf) {
      TNamed::operator=(lf);
      fNdata=lf.fNdata;
      fLen=lf.fLen;
      fLenType=lf.fLenType;
      fOffset=lf.fOffset;
      fIsRange=lf.fIsRange;
      fIsUnsigned=lf.fIsUnsigned;
      fLeafCount=lf.fLeafCount;
      fBranch=lf.fBranch;
   } 
   return *this;
}

//______________________________________________________________________________
TLeaf::~TLeaf()
{
   // -- Destructor.

   if (fBranch) {
      TTree* tree = fBranch->GetTree();
      fBranch = 0;
      if (tree) {
         TObjArray *lst = tree->GetListOfLeaves();
         if (lst->GetLast()!=-1) lst->Remove(this);
      }
   }
   fLeafCount = 0;
}

//______________________________________________________________________________
void TLeaf::Browse(TBrowser* b)
{
   // Browse the content of this leaf.

   if (strchr(GetName(), '.')) {
      fBranch->GetTree()->Draw(GetName(), "", b ? b->GetDrawOption() : "");
   } else {
      if ((fBranch->GetListOfLeaves()->GetEntries() > 1) || 
          (strcmp(fBranch->GetName(), GetName()) != 0)) {
         TString name;
         name.Form("%s.%s", fBranch->GetName(), GetName());
         fBranch->GetTree()->Draw(name, "", b ? b->GetDrawOption() : "");
      } else {
         fBranch->GetTree()->Draw(GetName(), "", b ? b->GetDrawOption() : "");
      }
   }
   if (gPad) {
      gPad->Update();
   }
}

//______________________________________________________________________________
void TLeaf::FillBasket(TBuffer &)
{
   // -- Pack leaf elements in Basket output buffer.
}

//______________________________________________________________________________
TLeaf* TLeaf::GetLeafCounter(Int_t& countval) const
{
   // -- Return a pointer to the counter of this leaf.
   //
   //  If leaf name has the form var[nelem], where nelem is alphanumeric, then
   //     If nelem is a leaf name, return countval = 1 and the pointer to 
   //          the leaf named nelem.
   //  If leaf name has the form var[nelem], where nelem is a digit, then
   //     return countval = nelem and a null pointer.
   //  If leaf name has the form of a multi dimenantion array (eg var[nelem][nelem2] 
   //     where nelem and nelem2 are digits) then
   //     return countval = product of all dimension size and a null pointer.
   //  If leaf name has the form var[... (and do not match the previous 2
   //     cases) return countval = -1 and null pointer;
   //  Otherwise return countval=1 and a null pointer.
   //

   countval = 1;
   const char* name = GetTitle();
   char* bleft = (char*) strchr(name, '[');
   if (!bleft) {
      return 0;
   }
   bleft++;
   Int_t nch = strlen(bleft);
   char* countname = new char[nch+1];
   strcpy(countname, bleft);
   char* bright = (char*) strchr(countname, ']');
   if (!bright) {
      delete[] countname;
      countname = 0;
      countval = -1;
      return 0;
   }
   char *bleft2 = (char*) strchr(countname, '[');
   *bright = 0;
   nch = strlen(countname);

   // Now search a branch name with a leave name = countname
   // We search for the leaf in the ListOfLeaves from the TTree. We can in principle
   // access the TTree by calling fBranch()->GetTree(), but fBranch is not set if this
   // method is called from the TLeaf constructor. In that case, use global pointer
   // gTree.
   // Also, if fBranch is set, but fBranch->GetTree() returns NULL, use gTree.
   TTree* pTree = gTree;
   if (fBranch && fBranch->GetTree()) {
      pTree = fBranch->GetTree();
   }
   TLeaf* leaf = (TLeaf*) GetBranch()->GetListOfLeaves()->FindObject(countname);
   if (leaf == 0) {
      // Try outside the branch:
      leaf = (TLeaf*) pTree->GetListOfLeaves()->FindObject(countname);
   }
   //if not found, make one more trial in case the leaf name has a "."
   if (!leaf && strchr(GetName(), '.')) {
      char* withdot = new char[strlen(GetName())+strlen(countname)+1];
      strcpy(withdot, GetName());
      char* lastdot = strrchr(withdot, '.');
      strcpy(lastdot, countname);
      leaf = (TLeaf*) pTree->GetListOfLeaves()->FindObject(countname);
      delete[] withdot;
      withdot = 0;
   }
   if (!leaf && strchr(countname,'.')) {
      // Not yet found and the countname has a dot in it, let's try
      // to find the leaf using its full name
      leaf = pTree->FindLeaf(countname);
   }
   Int_t i = 0;
   if (leaf) {
      countval = 1;
      leaf->SetRange();
      if (bleft2) {
         sscanf(bleft2, "[%d]", &i);
         countval *= i;
      }
      bleft = bleft2;
      while (bleft) {
         bleft2++;
         bleft = (char*) strchr(bleft2, '[');
         if (!bleft) {
            break;
         }
         sscanf(bleft, "[%d]", &i);
         countval *= i;
         bleft2 = bleft;
      }
      delete[] countname;
      countname = 0;
      return leaf;
   }
   // not found in a branch/leaf. Is it a numerical value?
   for (i = 0; i < nch; i++) {
      if (!isdigit(countname[i])) {
         delete[] countname;
         countname = 0;
         countval = -1;
         return 0;
      }
   }
   sscanf(countname, "%d", &countval);
   if (bleft2) {
      sscanf(bleft2, "[%d]", &i);
      countval *= i;
   }
   bleft = bleft2;
   while (bleft) {
      bleft2++;
      bleft = (char*) strchr(bleft2, '[');
      if (!bleft) {
         break;
      }
      sscanf(bleft, "[%d]", &i);
      countval *= i;
      bleft2 = bleft;
   }

   delete[] countname;
   countname = 0;
   return 0;
}

//______________________________________________________________________________
Int_t TLeaf::GetLen() const
{
   // -- Return the number of effective elements of this leaf.

   if (fLeafCount) {
      // -- We are a varying length array.
      Int_t len = Int_t(fLeafCount->GetValue());
      if (len > fLeafCount->GetMaximum()) {
         Error("GetLen", "Leaf counter is greater than maximum!  leaf: '%s' len: %d max: %d", GetName(), len, fLeafCount->GetMaximum());
         len = fLeafCount->GetMaximum();
      }
      return len * fLen;
   } else {
      // -- We are a fixed size thing.
      return fLen;
   }
}

//______________________________________________________________________________
Int_t TLeaf::ResetAddress(void* addr, Bool_t calledFromDestructor)
{
   // -- Helper routine for TLeafX::SetAddress.
   //
   // The return value is non-zero if we owned the old
   // value buffer and must delete it now.  The size
   // of the value buffer is recalculated and stored,
   // and a decision is made whether or not we own the
   // new value buffer.
   //

   // The kNewValue bit records whether or not we own
   // the current value buffer or not.  If we own it,
   // then we are responsible for deleting it.
   Bool_t deleteValue = kFALSE;
   if (TestBit(kNewValue)) {
      deleteValue = kTRUE;
   }
   // If we are not being called from a destructor,
   // recalculate the value buffer size and decide
   // whether or not we own the new value buffer.
   if (!calledFromDestructor) {
      // -- Recalculate value buffer size and decide ownership of value.
      if (fLeafCount) {
         // -- Varying length array data member.
         fNdata = (fLeafCount->GetMaximum() + 1) * fLen;
      } else {
         // -- Fixed size data member.
         fNdata = fLen;
      }
      // If we were provided an address, then we do not own
      // the value, otherwise we do and must delete it later,
      // keep track of this with bit kNewValue.
      if (addr) {
         ResetBit(kNewValue);
      } else {
         SetBit(kNewValue);
      }
   }
   return deleteValue;
}

//_______________________________________________________________________
void TLeaf::SetLeafCount(TLeaf *leaf)
{ 
   // -- Set the leaf count of this leaf.

   if (IsZombie() && (fLen == -1) && leaf) {
      // The constructor noted that it could not find the 
      // leafcount.  Now that we did find it, let's remove
      // the side-effects.
      ResetBit(kZombie);
      fLen = 1;
   }
   fLeafCount = leaf; 
}

//_______________________________________________________________________
void TLeaf::Streamer(TBuffer &b)
{
   // -- Stream a class object.

   if (b.IsReading()) {
      UInt_t R__s, R__c;
      Version_t R__v = b.ReadVersion(&R__s, &R__c);
      if (R__v > 1) {
         b.ReadClassBuffer(TLeaf::Class(), this, R__v, R__s, R__c);
      } else {
         // -- Process old versions before automatic schema evolution.
         TNamed::Streamer(b);
         b >> fLen;
         b >> fLenType;
         b >> fOffset;
         b >> fIsRange;
         b >> fIsUnsigned;
         b >> fLeafCount;
         b.CheckByteCount(R__s, R__c, TLeaf::IsA());
      }
      if (!fLen) {
         fLen = 1;
      }
      // We do not own the value buffer right now.
      ResetBit(kNewValue);
      SetAddress();
   } else {
      b.WriteClassBuffer(TLeaf::Class(), this);
   }
}

---