TConvertingBranchElement Class Reference

A variant of TBranchElement that can call converters when reading objects in split mode. More...

#include <TConvertingBranchElement.h>

Inheritance diagram for TConvertingBranchElement:

Collaboration diagram for TConvertingBranchElement:

Public Member Functions
	TConvertingBranchElement ()
	Constructor.
virtual	~TConvertingBranchElement ()
	Destructor.
virtual Int_t	GetEntry (Long64_t entry, Int_t getall)
	Read all branches into the previously-declared object.
virtual void	Streamer (TBuffer &R__b)
	Read or write this object.
virtual void	SetAddress (void *add)
	Set the address of the object to use for I/O.
virtual void	ResetAddress ()
	Reset branch addresses and maybe delete the object.

Static Public Member Functions
static void	Initialize ()
	Set up to allow for conversions in split mode.
static void	SetDoDel (bool flag)
	Set the deletion flag.

Protected Member Functions
virtual void	InitInfo ()
	Initialize the TStreamerInfo pointer.
virtual void	InitializeOffsets ()
	Initialize data member offsets.
void	ReadLeavesCollectionConverting (TBuffer &b)
	Read leaves into I/O buffers for this branch.
void	ReadLeavesMemberBranchCountConverting (TBuffer &b)

Private Member Functions
void	BuildConvertedElisions ()
	Add dummy nodes if needed to recover the correct tree structure.
void	CheckForConversion ()
	Check to see if we need to worry about conversions for this branch.
void	ConvResetType ()
	Recursively reset the type field of containers in conversions.
Int_t	ReadSubBranches (Long64_t entry, Int_t getall, bool dont_reset)
	@branch Read in the subbranches of this branch.
TConvertingBranchElement &	operator= (const TConvertingBranchElement &)
	If true, try to delete the.
	TConvertingBranchElement (const TConvertingBranchElement &)

Static Private Member Functions
static void *	new_TConvertingBranchElement (void *p)
	new() method for this object.

Private Attributes
TVirtualConverter *	fConv
TClass *	fConvClass
	Conversion for this branch.
char *	fConvObject
	Class for conversion.
TObjArray *	fConvOrigBranches
	Pointer to tmp obj used for conversion.
Int_t	fConvOrigType
	Saved branch list. If we change.
bool	fConvContainerFlag
	Saved branch type. The original.
bool	fConvDontReset
	True if we're doing a container.

Static Private Attributes
static constexpr unsigned int	kIsDummy = BIT(20)
	Flag used to mark dummy nodes created by BuildConvertedElisions.
static std::atomic< bool >	fgDoDel = false
	Flag that the next read should.

Detailed Description

A variant of TBranchElement that can call converters when reading objects in split mode.

Definition at line 64 of file TConvertingBranchElement.h.

Constructor & Destructor Documentation

TConvertingBranchElement() [1/2]

TConvertingBranchElement::TConvertingBranchElement

(

)

Constructor.

Definition at line 287 of file TConvertingBranchElement.cxx.

: fConv(nullptr)
, fConvClass(nullptr)
, fConvObject(nullptr)
, fConvOrigBranches(nullptr)
, fConvOrigType(-1)
, fConvContainerFlag(false)
, fConvDontReset(false)
{
}

~TConvertingBranchElement()

TConvertingBranchElement::~TConvertingBranchElement ( )

virtual

Destructor.

Constructor.

Get rid of any temporary objects which we made.

Definition at line 304 of file TConvertingBranchElement.cxx.

{
  // If we made a temporary object instance for conversions, delete it.
  if (fConv && fConvObject)
    fConv->DeletePersObj (fConvObject);
 
  // If we contain dummy branches, delete them here.
  // In that case, we should also delete the saved original branch list.
  if (fConvOrigBranches) {
    Int_t nbranches = fBranches.GetEntriesFast();
    for (Int_t i = 0; i < nbranches; i++) {
      if (fBranches[i]->TestBit (kIsDummy))
        delete fBranches[i];
    }
    fBranches = *fConvOrigBranches;
    delete fConvOrigBranches;
  }
 
  // If we're a dummy ourselves, we should delete the branch list.
  if (TestBit (kIsDummy))
    fBranches.Clear();
  
  // Try to delete the object, if requested.
  if (fgDoDel)
    TConvertingBranchElement::ResetAddress();
}

TConvertingBranchElement() [2/2]

TConvertingBranchElement::TConvertingBranchElement ( const TConvertingBranchElement & )

private

Member Function Documentation

BuildConvertedElisions()

void TConvertingBranchElement::BuildConvertedElisions ( )

private

Add dummy nodes if needed to recover the correct tree structure.

Given a TBranchElement tree structure, Root will elide some of the intermediate tree nodes. For example, given:

a a.b a.b.c a.b.c.d1 a.b.c.d2

Root will elide the ‘c’ node — so one has node ‘a’, with child ‘a.b’, with children ‘a.b.c.d1’ and ‘a.b.c.d2’.

This greatly complicates the process of running conversions, if ‘c’ has a conversion. So, what we do is if we determine that a conversion is needed, we modify the tree to reinsert the elided nodes. These nodes will have the kIsDummy flag set. Further, if we do that, we remember the original branch list from the parent node (‘a.b’ in the above example), so that if the structure is written, we can write the original, elided structure.

Definition at line 380 of file TConvertingBranchElement.cxx.

{
  // Can't do anything if we can't find the @c TStreamerInfo.
  if (!fInfo) return;
 
  // The class of this branch's element.
  TClass* topclass = nullptr;
  if (fID < 0)
    topclass = gROOT->GetClass (GetClassName());
  else {
    std::string s = BasenameOfBranch (GetName());
    int offset = 0;
    TStreamerElement* elt = fInfo->GetStreamerElement(s.c_str(), offset);
    if (elt)
      topclass = elt->GetClass();
  }
  if (!topclass) return;
 
  // Here's the plan.
  // We start by adding all branches to the @c branches list.
  // Then we walk through the members of this class (using the
  // @c TStreamerInfo).
  // If this member is contained in the branch list, then we
  // remove it from @c branches and add it to @c noconv_branches
  // (it wasn't elided).
  // If it's not in the branch list, then it was elided.
  // We look then to see if the corresponding class (or anything
  // it contains) requires a conversion.  If so, then we build
  // a dummy node for it, and add the dummy to @c conv_dummies.
  // We then look through @c branches, find any that actually
  // belong to the new dummy node, remove them from @c branches,
  // and add them to the dummy.
  // If no conversion is needed, then we don't need to do anything
  // at this point.
  //
  // When we're done scanning all the members of the class, we take
  // anything remaining in @c branches and move to @c noconv_branches
  // (these correspond to branches with elided nodes, but with
  // no conversions required.)  Then, if we made any dummy nodes,
  // then we replace our branch list with the concatenation of the
  // dummy list and the @c noconv_branches list (saving the original
  // branch list so that we can restore it later, if needed).
  std::vector<TBranch*> conv_dummies;
  std::vector<TBranch*> noconv_branches;
  std::vector<TBranch*> branches;
 
  // To start with, add all our child branches to @c branches.
  Int_t nbranches = fBranches.GetEntriesFast();
  branches.reserve (nbranches);
  for (Int_t i=0; i < nbranches; i++) {
    TBranch* b = dynamic_cast<TBranchElement*> (fBranches[i]);
    if (b)
      branches.push_back (b);
  }
 
  // Get the @c TStreamerInfo for this class.
  // If this class is a container, then we actually want
  // to get the @c TStreamerInfo for the contained class.
  TStreamerInfo* info = GetStreamerInfoFromFile (topclass, this);
  if (!info && fType == 4) {
    TVirtualCollectionProxy* proxy = topclass->GetCollectionProxy();
    if (!proxy) return;
    topclass = proxy->GetValueClass();
    if (!topclass) return;
    info = GetStreamerInfoFromFile (topclass, this);
  }
  else if (fType == 3) {
    topclass = gROOT->GetClass (fClonesName);
    if (!topclass) return;
    info = GetStreamerInfoFromFile (topclass, this);
  }
  if (!info) return;
 
  // Now walk through all elements in the @c TStreamerInfo.
  TObjArray* elems = info->GetElements();
  size_t ndata = elems->GetEntriesFast();
  for (size_t ielt = 0; ielt < ndata; ++ielt) {
    // The element.
    TStreamerElement* elt =
      reinterpret_cast<TStreamerElement*> (elems->At(ielt));
 
    // See if there's a branch corresponding to this element.
    // If so, add it to the noconv list.
    bool found = false;
    for (unsigned i=0; i < branches.size(); i++) {
      TBranchElement* b = dynamic_cast<TBranchElement*>(branches[i]);
 
      // Test branch @b to see if corresponds to the SI element @ elt.
      if (b && gROOT->GetClass (b->GetClassName()) == topclass) {
        if (dynamic_cast<TStreamerBase*> (elt) != 0 && b->GetType() == 1) {
          // For a base class, the test above is sufficient.
          found = true;
        }
        else {
          // Test the name.
          std::string s = BasenameOfBranch (b->GetName());
          if (s == elt->GetName())
            found = true;
        }
 
        if (found) {
          // We found a branch matching the element.
          // Move the branch from @c branches to @c noconv_branches,
          // and exit the loop over branches.
          noconv_branches.push_back (b);
          branches.erase (branches.begin()+i);
          break;
        }
      }
    }
 
    if (!found) {
      // We didn't find a branch corresponding to this element.
      // Maybe this is an elided class.
      // If this is a class type, then see if it or anything
      // it contains has a conversion.  If so, then build a dummy
      // node for it.
      TClass* cl = elt->GetClass();
      if (cl && DoesClassNeedConv (cl, this)) {
        // It needs a conversion.  Make a dummy node.
        TClass* clparent = gROOT->GetClass (info->GetName());
        TConvertingBranchElement* dum = new TConvertingBranchElement;
        dum->SetBit (kIsDummy);
        TString name;
        if (fID < 0)
          name = elt->GetName();
        else {
          name = GetName();
          if (fType == 1) {
            Ssiz_t i = name.Length()-1;
            while (i >= 0 && name[i] != '.')
              --i;
            name.Remove (i+1);
          }
          else
            name += ".";
          name += elt->GetName();
        }
        dum->SetName (name);
        dum->SetTitle (name);
        TString namedot = name + ".";
        dum->SetParentClass (clparent);
        dum->SetClassName (info->GetName());
        dum->fCheckSum = info->GetCheckSum();
        dum->fClassVersion = topclass->GetClassVersion();
        dum->fID = ielt;
        dum->fTree = this->fTree;
        dum->fDirectory = this->fDirectory;
        dum->fBranchClass = topclass;
        if (dynamic_cast<TStreamerBase*> (elt) != nullptr) {
          dum->fType = 1;
          Ssiz_t i = namedot.Length()-2;
          while (i >= 0 && namedot[i] != '.')
            --i;
          namedot.Remove (i+1);
        }
        else
          dum->fType = 2;
 
        // Add the dummy node to @c conv_dummies.
        conv_dummies.push_back (dum);
        
        // Find all branches that are a part of this class and
        // move them from @c branches to the dummy node
        for (unsigned i=0; i < branches.size(); ) {
          TString bname = branches[i]->GetName();
          if (bname.Index (namedot) == 0 &&
              (dum->fType == 2 ||
               BaseHasField (dynamic_cast<TStreamerBase*>(elt),
                             bname,
                             namedot,
                             this)))
          {
            dum->GetListOfBranches()->Add (branches[i]);
            if (TConvertingBranchElement* be =
                dynamic_cast<TConvertingBranchElement*> (branches[i]))
            {
              be->fParentClass = cl;
            }
            branches.erase (branches.begin()+i);
          }
          else {
            ++i;
          }
        }
      }
    }
    // End of loop over elements.
  }
 
  // Any remaining branches go to @c noconv_branches.
  for (unsigned int i=0; i < branches.size(); i++)
    noconv_branches.push_back (branches[i]);
 
  if (conv_dummies.size() > 0) {
    // We made some dummies.
    // Replace our branch list with the concatenation
    // of the dummy list (@c conv_dummies) and the branches
    // that don't need special processing (@c noconv_branches --- because
    // they either did not have an elision or they didn't require
    // a conversion).
    fConvOrigBranches = new TObjArray;
    *fConvOrigBranches = fBranches;
    fBranches.Clear();
    for (unsigned int i=0; i < conv_dummies.size(); i++)
      fBranches.Add (conv_dummies[i]);
    for (unsigned int i=0; i < noconv_branches.size(); i++)
      fBranches.Add (noconv_branches[i]);
  }
}

CheckForConversion()

void TConvertingBranchElement::CheckForConversion ( )

private

Check to see if we need to worry about conversions for this branch.

Set up member variables if so.

Definition at line 596 of file TConvertingBranchElement.cxx.

{
  // Need @c TStreamerInfo in order to do anything.
  if (!fInfo) return;
 
  // Restore any elided tree nodes if there's a conversion.
  BuildConvertedElisions();
 
  // See if this element is a class.
  const char* classname = 0;
  int checksum = 0;
 
  if (fID < 0) {
    // Special case for top-level branch.
    classname = GetClassName();
    checksum = fCheckSum;
  }
  else {
    // Otherwise, we need to look at the streamerinfo element.
    std::string s = BasenameOfBranch (GetName());
    int offset = 0;
    TStreamerElement* elt = fInfo->GetStreamerElement(s.c_str(), offset);
    if (elt) {
      TClass* cl = elt->GetClass();
      if (cl) {
        classname = cl->GetName();
        TStreamerInfo* info = GetStreamerInfoFromFile (cl, this);
        if (info)
          checksum = info->GetCheckSum();
      }
    }
  }
 
  if (classname) {
    // Ok, this branch represents a class.
    // See if there's a conversion for it.
    TVirtualConverter* conv =
      TConverterRegistry::Instance()->GetConverter (classname, checksum);
 
    // If there's not a conversion and this class is a container,
    // then we need to see if something in the container needs a conversion.
    if (!conv && (fType == 4 || fType == 3)) {
      // Find the contained class.
      TClass* contclass = gROOT->GetClass (fClonesName.Data());
      if (contclass) {
        TStreamerInfo* info = GetStreamerInfoFromFile (contclass, this);
        if (info) {
          // Found the contained class with its @c TStreamerInfo.
          // See if the contained class has a conversion.
          conv =
            TConverterRegistry::Instance()->GetConverter (fClonesName.Data(),
                                                          info->GetCheckSum());
 
          // If the contained class, or anything it contains, has a conversion,
          // then we need to deal with conversions when reading this container.
          if (conv || DoesClassNeedConv (contclass, this)) {
            fConvContainerFlag = true;
            ConvResetType();
          }
        }
      }
    }
 
    if (conv) {
      TClass* convclass = conv->GetPersClass();
      if (convclass) {
        // We have a conversion!  Remember the converter and persistent
        // class, and create the temporary persistent class instance.
        fConv = conv;
        fConvClass = convclass;
        fConvObject = (char*)conv->NewPersObj();
      }
    }
  }
 
  // Now see if the class containing this element has a conversion.
  if (fID > -1) {
    TVirtualConverter* conv =
      TConverterRegistry::Instance()->GetConverter (GetClassName(),
                                                    fCheckSum);
    if (conv) {
      TClass* convclass = conv->GetPersClass();
      if (convclass) {
        // The class containing this class has a conversion.
        // Change the @c TStreamerInfo to correspond to the
        // appropriate persistent class; also change the parent class
        // pointer.
        Bool_t optim = TStreamerInfo::CanOptimize();
        TStreamerInfo::Optimize(kFALSE);
        TStreamerInfo* info =
          dynamic_cast<TStreamerInfo*> (convclass->GetStreamerInfo (0));
        if (info)
          fInfo = info;
        TStreamerInfo::Optimize(optim);
        fParentClass = convclass;
      }
    }
  }
}

ConvResetType()

void TConvertingBranchElement::ConvResetType ( )

private

Recursively reset the type field of containers in conversions.

Recursively reset the type field of container elts in conversions.

Walk recursively through all children of this node. Any of them that have a fType corresponding to a member field within a container (31 or 41) are reset to 2 (normal member).

Definition at line 738 of file TConvertingBranchElement.cxx.

{
  Int_t nbranches = fBranches.GetEntriesFast();
  for (Int_t i=0; i < nbranches; i++) {
    TConvertingBranchElement* b =
      dynamic_cast<TConvertingBranchElement*> (fBranches[i]);
    if (b) {
      if (b->fType == 41 || b->fType == 31) {
        b->fConvOrigType = b->fType;
        b->fType = 2;
      }
      b->ConvResetType();
    }
  }
}

GetEntry()

Int_t TConvertingBranchElement::GetEntry ( Long64_t entry, Int_t getall )

virtual

Read all branches into the previously-declared object.

Parameters

entry	The ntuple row to read.
getall	If true, force reading all branches, even those previously deactivated.

If entry = 0, then use current entry number + 1. If entry < 0, then reset entry number to 0.

Returns the number of bytes read from the input buffer. If entry does not exist, then returns 0. If an I/O error occurs, then returns -1.

Parameters

entry	The ntuple row to read.
getall	If true, force reading all branches, even those previously deactivated.

If entry = 0, then use current entry number + 1. If entry < 0, then reset entry number to 0.

Returns the number of bytes read from the input buffer. If entry does not exist, then returns 0. If an I/O error occurs, then returns -1.

Some notes about conversions. If this branch has a conversion, then rather than reading directly into the target address, we instead read into a temporary object of the persistent type (fConvObject), and then call the converter to copy from the persistent to the transient object. We override SetAddress so that this will get set correctly for children of converted classes.

Note that the need to call the converter from the branch node corresponding to the class with the conversion is why we have problems with elided tree nodes — and the reason for BuildConvertedElisions.

Containers are more complicated. Suppose we have something like:

struct A { int a1; int a2; }; struct B { int b1; A b2; }; struct C { std::vector c1; };

and we're working on the vector.

The way Root handles this is that we have three branches: c1.b1, c1.b1.a1, c1.b1.a2 holding the container data. In addition, the container branch c1 will hold the count of the number of elements in the container. What Root does is:

• First read the element count from branch c1. This will be stored in the c1 TBranchElement. Its children point to it to get the number of elements.
• We then loop over the branches.
• We read all elements at once for each branch, via TBranchInfo::ReadBufferSTL. We get the number of elements by looking in the parent container branch. Note that for the children of the container, the address set via SetAddress is not the address of the object itself, but rather the address of a collection proxy. The proxy is then associated with the actual container being read.

Now, when we try to do this with conversions, we run into the problem that we need the complete object in order to run the conversion. One way of doing this would be to buffer the complete collection of persistent objects, then loop over them calling the converter. I wanted to avoid having to do that for large collections, so what's done here is somewhat more complicated. The idea is to change the order of the loop over the branches and the loop over the elements, so that we make one complete object at a time. In a little more detail:

• We change the type of the children of the containers from 31/41 (member field of container) to 2 (normal member).
• When reading the collection branch, we read the number of elements, then loop over each element. For each element, we loop over each branch, calling GetEntry. But first, we call SetAddress to pass in the address of the temporary persistent object (if a conversion is being done for the object directly contained by the container) or the address of the object in the container (if the conversion is further down).
• A complication is that normally when GetEntry is called for a member in a container, it (via ReadLeaves) resets the TBuffer to point at the first element in the collection. Because of how we've rearranged the loops, we want this to happen only on the first time. To accomplish this, a ‘dont_reset’ flag is introduced, to tell GetEntry not to call ReadLeaves. It would be most natural to do this by adding a parameter to GetEntry. However, at this point, we do not want to change the GetEntry interface. So, instead of passing this as an argument, it's passed in a member variable, fConvDontReset.

All of this is handled by the following methods: GetEntry ReadLeaves ReadSubBranches

Definition at line 843 of file TConvertingBranchElement.cxx.

{
  // The first part of this just copies the base class @c GetEntry.
  // Differences from the base class implementation will be pointed out below.
 
  // Remember which entry we are reading.
  fReadEntry = entry;
 
  // If our tree has a branch ref, make it remember the entry and
  // this branch.  This allows a TRef::GetObject() call done during
  // the following I/O operation, for example in a custom streamer,
  // to search for the referenced object in the proper element of the
  // proper branch.
  TBranchRef* bref = fTree->GetBranchRef();
  if (bref) {
    bref->SetParent(this, fBranchID);
    bref->SetRequestedEntry(entry);
  }
 
  Int_t nbytes = 0;
 
  SetupAddresses();
 
  Int_t nbranches = fBranches.GetEntriesFast();
  if (nbranches) {
    // -- Branch has daughters.
    // One must always read the branch counter.
    // In the case when one reads consecutively twice the same entry,
    // the user may have cleared the TClonesArray between the GetEntry calls.
    if ((fType == 3) || (fType == 4)) {
      Int_t nb = TBranch::GetEntry(entry, getall);
      if (nb < 0) {
        return nb;
      }
      nbytes += nb;
    }
 
    // Here's a difference from the @c TBranchElement base class.
    // First, we need to pick up the current state of the
    // @c fConvDontReset flag (and clear it in the process).
    // Instead of looping over branches here, we factor out
    // that part into @c ReadSubBranches.
    bool dont_reset = fConvDontReset;
    fConvDontReset = false;
    switch(fSTLtype) {
    case TClassEdit::kSet:
    case TClassEdit::kMultiSet:
    case TClassEdit::kMap:
    case TClassEdit::kMultiMap:
      break;
    default:
      // Read non-container composite and list/vector.
      // Associative containers will get entirely read
      // within the @c GetEntry call above (when it calls @c ReadLeaves).
      nbytes += ReadSubBranches (entry, getall, dont_reset);
      break;
    }
  }
  else {
    // -- Terminal branch.
    // Difference from base implementation: pick up the dont_reset flag here.
    bool dont_reset = fConvDontReset;
    fConvDontReset = false;
 
    if (fBranchCount && (fBranchCount->GetReadEntry() != entry)) {
      Int_t nb = fBranchCount->TBranch::GetEntry(entry, getall);
      if (nb < 0) {
        return nb;
      }
      nbytes += nb;
    }
    Int_t nb = 0;
 
    // The base implementation just calls @c TBranch::GetEntry here.
    // But we need to pay attention to the dont_reset flag.
    // If it's set, we can't call @c TBranch::GetEntry (because
    // that would reset the buffer pointer back to the
    // beginning of the container).  Instead, we pick up the
    // buffer pointer and call @c ReadLeaves `by hand'.
    if (dont_reset) {
      TBasket* basket = (TBasket*)GetBasket(GetReadBasket());
      TBuffer* buffer = basket->GetBufferRef();
      Int_t bufbegin = buffer->Length();
 
      // Suppress false positive seen with gcc.
#if __GNUC__ >= 11 && __GNUC__ <= 14
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
#endif
      (this->*fReadLeaves) (*buffer);
#if __GNUC__ >= 11 && __GNUC__ <= 14
# pragma GCC diagnostic pop
#endif
 
      nb = buffer->Length() - bufbegin;
    }
    else
      nb = TBranch::GetEntry (entry, getall);
 
    // Rest is the same as the base implementation.
    if (nb < 0) {
      return nb;
    }
    nbytes += nb;
  }
  
  if (fTree->Debug() > 0) {
    if ((entry >= fTree->GetDebugMin()) && (entry <= fTree->GetDebugMax())) {
      Info("GetEntry", "%lld, branch=%s, nbytes=%d", entry, GetName(), nbytes);
    }
  }
  return nbytes;
}

Initialize()

void TConvertingBranchElement::Initialize ( )

static

Set up to allow for conversions in split mode.

Definition at line 335 of file TConvertingBranchElement.cxx.

{
}

InitializeOffsets()

void TConvertingBranchElement::InitializeOffsets ( )

protectedvirtual

Initialize data member offsets.

(Overridden internal method.)

Definition at line 1286 of file TConvertingBranchElement.cxx.

{
  // previously in InitializeOffsets, after:
  //  if (fType == 1) {
  //    pClass = branchElem->GetClassPointer();
  //  } else {
  //    pClass = subBranch->GetParentClass();
  //  }
  //
  // i had:
  //
  //  if (fConvClass) pClass = fConvClass;
  //
  // This is a hack so we don't need to modify the base class
  // InitializeOffsets.
  //
  TStreamerElement* branchElem = 0;
  TClass* cl_orig = 0;
  if (fConvClass && fID > -1) {
    TStreamerInfo* si = GetInfo();
    branchElem = si->GetElem(fID);
    if (branchElem) {
      if (branchElem && branchElem->IsBase()) {
        cl_orig = branchElem->GetClassPointer();
        branchElem->Update (cl_orig, fConvClass);
      }
      else
        branchElem = 0;
    }
  }
 
  if (fConvClass) {
    Int_t nbranches = fBranches.GetEntriesFast();
    for (Int_t subBranchIdx = 0; subBranchIdx < nbranches; ++subBranchIdx) {
      TConvertingBranchElement* br = 
        dynamic_cast<TConvertingBranchElement*> (fBranches[subBranchIdx]);
      if (br) {
        br->fParentClass = fConvClass;
      }
    }
  }
 
  TBranchElement::InitializeOffsets();
 
  if (branchElem)
    branchElem->Update (fConvClass, cl_orig);
}

InitInfo()

void TConvertingBranchElement::InitInfo ( )

protectedvirtual

Initialize the TStreamerInfo pointer.

(Overridden internal method.)

(Overridden internal method.)

This gets called by GetInfo if the fInfo pointer is null. It should initialize that pointer.

Here is where we check for a conversion.

Definition at line 706 of file TConvertingBranchElement.cxx.

{
  // Do the standard stuff.
  TBranchElement::InitInfo();
 
  //  Check for a conversion.
  if (fInfo) {
    const_cast<TConvertingBranchElement*>(this)->CheckForConversion();
 
    // Re-find the fID.
    const_cast<TConvertingBranchElement*>(this)->fInit = kFALSE;
    TBranchElement::InitInfo();
  }
 
  // Change ReadLeaves implementation if needed.
  // The base class implementation works here except for the case
  // of an STL associative container.  We need to change the code
  // for that to notice @c fConvDontReset and to use @c ReadSubBranches.
  if (fType == 4)
    fReadLeaves = (ReadLeaves_t)&TConvertingBranchElement::ReadLeavesCollectionConverting;
  else if (fType == 2 && (fConvOrigType == 41 || fConvOrigType == 31))
    fReadLeaves = (ReadLeaves_t)&TConvertingBranchElement::ReadLeavesMemberBranchCountConverting;
}

new_TConvertingBranchElement()

void * TConvertingBranchElement::new_TConvertingBranchElement ( void * p )

staticprivate

new() method for this object.

Parameters

p	Address for placement new, or nullptr.

Returns

Address of the new object.

This is installed as the New method in TBranchElement's TClass. Thus, when we read from a file a TBranchElement, we actually make an instance of this class.

Parameters

p	Address for placement new, or 0.

Returns

Address of the new object.

This is installed as the New method in TBranchElement's TClass. Thus, when we read from a file a TBranchElement, we actually make an instance of this class.

Definition at line 349 of file TConvertingBranchElement.cxx.

{
  if (p)
    return new (p) TConvertingBranchElement;
  return new TConvertingBranchElement;
}

operator=()

TConvertingBranchElement & TConvertingBranchElement::operator= ( const TConvertingBranchElement & )

private

If true, try to delete the.

ReadLeavesCollectionConverting()

void TConvertingBranchElement::ReadLeavesCollectionConverting ( TBuffer & b )

protected

Read leaves into I/O buffers for this branch.

Parameters

b	Root I/O buffer.

Definition at line 962 of file TConvertingBranchElement.cxx.

{
   // -- Read leaves into i/o buffers for this branch.
   // Case of a collection (fType == 4).
   
   ValidateAddress();
   if (fObject == 0)
   {
      // We have nowhere to copy the data (probably because the data member was
      // 'dropped' from the current schema) so let's no copy it in a random place.
      return;
   }
   
   // STL container master branch (has only the number of elements).
   Int_t n;
   b >> n;
   if ((n < 0) || (n > fMaximum)) {
      if (IsMissingCollection()) {
         n = 0;
         b.SetBufferOffset(b.Length()-sizeof(n));
      } else {
         Error("ReadLeaves", "Incorrect size read for the container in %s\n\tThe size read is %d while the maximum is %d\n\tThe size is reset to 0 for this entry (%lld)", GetName(), n, fMaximum, GetReadEntry());
         n = 0;
      }
   }
   fNdata = n;
 
   R__PushCache onfileObject((static_cast<TBufferFile&>(b)),fOnfileObject,n);
 
   if (!fObject) {
      return;
   }
   // Note: Proxy-helper needs to "embrace" the entire
   //       streaming of this STL container if the container
   //       is a set/multiset/map/multimap (what we do not
   //       know here).
   //       For vector/list/deque Allocate == Resize
   //                         and Commit   == noop.
   // TODO: Exception safety a la TPushPop
   TVirtualCollectionProxy* proxy = GetCollectionProxy();
   TVirtualCollectionProxy::TPushPop helper(proxy, fObject);
   void* alternate = proxy->Allocate(fNdata, true);
   if(fSTLtype != TClassEdit::kVector && proxy->HasPointers() && fSplitLevel > TTree::kSplitCollectionOfPointers ) {
      fPtrIterators->CreateIterators(alternate, proxy);
   } else {
      fIterators->CreateIterators(alternate, proxy);
   }      
   
   //Int_t nbranches = fBranches.GetEntriesFast();
   switch (fSTLtype) {
      case TClassEdit::kSet:
      case TClassEdit::kMultiSet:
      case TClassEdit::kMap:
      case TClassEdit::kMultiMap:
        {
          // Change for conversions:
          // Use @c ReadSubBranches and obey @c fConvDontReset.
          bool dont_reset = fConvDontReset;
          fConvDontReset = false;
          ReadSubBranches (GetReadEntry(), 1, dont_reset);
        }
        break;
      default:
         break;
   }
   //------------------------------------------------------------------------
   // We have split this stuff, so we need to create the the pointers
   //-----------------------------------------------------------------------
   if( proxy->HasPointers() && fSplitLevel > TTree::kSplitCollectionOfPointers )
   {
      TClass *elClass = proxy->GetValueClass();
      
      //--------------------------------------------------------------------
      // The allocation is done in this strange way because ReadLeaves
      // is being called many times by TTreeFormula!!!
      //--------------------------------------------------------------------
      Int_t i = 0;
      if( !fNdata || *(void**)proxy->At( 0 ) != 0 )
         i = fNdata;
      
      for( ; i < fNdata; ++i )
      {
         void **el = (void**)proxy->At( i );
         // coverity[dereference] since this is a member streaming action by definition the collection contains objects and elClass is not null.
         *el = elClass->New();
      }
   }
   
   proxy->Commit(alternate);   
}

ReadLeavesMemberBranchCountConverting()

void TConvertingBranchElement::ReadLeavesMemberBranchCountConverting ( TBuffer & b )

protected

Definition at line 1054 of file TConvertingBranchElement.cxx.

{
   // -- Read leaves into i/o buffers for this branch.
   // For split-class branch, base class branch, data member branch, or top-level branch.
   // which do have a branch count and are not a counter.
   
   assert(fStreamerType != TVirtualStreamerInfo::kCounter);
 
   ValidateAddress();
   if (fObject == 0)
   {
      // We have nowhere to copy the data (probably because the data member was
      // 'dropped' from the current schema) so let's no copy it in a random place.
      return;
   }
 
   R__PushCache onfileObject((static_cast<TBufferFile&>(b)),fOnfileObject,1);
   // If not a TClonesArray or STL container master branch
   // or sub-branch and branch inherits from tobject,
   // then register with the buffer so that pointers are
   // handled properly.
   if (TestBit(kBranchObject)) {
      b.ResetMap();
      b.MapObject((TObject*) fObject);
   } else if (TestBit(kBranchAny)) {
      b.ResetMap();
      b.MapObject(fObject, fBranchClass);
   }
   
   fNdata = (Int_t) fBranchCount->GetValue(0, 0);
   TStreamerInfo *info = GetInfo();
   if (!info) {
      return;
   }
   // Since info is not null, fReadActionSequence is not null either.
   //b.ReadSequence(*fReadActionSequence, fObject);
   // FIXME!
   // ReadSequence doesn't work here, since it gets structure offsets
   // from TConfiguration, and those haven't been adjusted to take
   // into account the use of the temporary conversion objects.
   // FIXME!
   std::abort();
   //doesn't work
   //info->ReadBuffer (b, (char**)&fObject, fID);
}

ReadSubBranches()

Int_t TConvertingBranchElement::ReadSubBranches ( Long64_t entry, Int_t getall, bool dont_reset )

private

@branch Read in the subbranches of this branch.

Parameters

entry	The entry number to read.
getall	If true, read all branches, even if disabled.
dont_reset	If true, don't reset the TBuffer read pointer.

Returns

The number of bytes read.

Parameters

entry	The entry number to read.
getall	If true, read all branches, even if disabled.
dont_reset	If true, don't reset the TBuffer read pointer.

Returns

The number of bytes read.

This is used to factor out the handling of conversions in containers.

Definition at line 1110 of file TConvertingBranchElement.cxx.

{
  Int_t nbytes = 0;
  Int_t nbranches = fBranches.GetEntriesFast();
 
  if (fConvContainerFlag) {
    if (fNdata > 0) {
      // We're reading a container that needs a conversion.
      // We're going to invert the loop order so that we read
      // a single object at a time,
      // Remember the number of entries in the container, but change
      // the number we advertise to 1.
      UInt_t save_ndata = fNdata;
      fNdata = 1;
 
      // Get either the container proxy or the clones array, as appropriate.
      TVirtualCollectionProxy* proxy = 0;
      TClonesArray* clones = 0;
      if (fType == 4)
        proxy = GetCollectionProxy();
      else if (fType == 3)
        clones = (TClonesArray*)fObject;
      else
        abort();
 
      // If we had a proxy, associate it with the container object.
      // This is safe for the case where proxy is null.
      TPushPopSafe helper (proxy,fObject);
 
      // For each element, we may have to call @c SetAddress for each
      // branch.  This is used to avoid doing this repeatedly
      // with the same address (as would happen if we're reading into
      // the temporary persistent object).
      std::vector<char*> last_addrs (nbranches, (char*)0);
 
      // Loop over elements.
      for (UInt_t j = 0; j < save_ndata; j++) {
        // Find the address of the element we want to initialize.
        // How we do this depends on whether we have a @c TClonesArray
        // or a proxy.
        char* addr = 0;
        if (proxy)
          addr = (char*)(proxy->At(j));
        else {
          if (!clones) std::abort();
          addr = (char*)((*clones)[j]);
        }
 
        // The address of the object we want to read.
        // If we have a conversion on the class contained directly
        // in the container, then this will be the temporary persistent
        // object.  Otherwise, it will be the address we found in the
        // last line.
        char* obj = fConvObject ? fConvObject : addr;
 
        // Loop over branches for a single object.
        for (Int_t i = 0; i < nbranches; ++i) {
          TBranch* branch = (TBranch*) fBranches[i];
 
          // If this isn't the first element in the container,
          // then we'll need to set the dont_reset flag.
          if (j > 0) {
            TConvertingBranchElement* be =
              dynamic_cast<TConvertingBranchElement*>(branch);
            if (be)
              be->fConvDontReset = true;
          }
 
          // Find the address for this member,
          char* this_addr = obj + fBranchOffset[i];
 
          // Call @c SetAddress if it's different from the last one we set.
          if (this_addr != last_addrs[i]) {
            last_addrs[i] = this_addr;
            branch->SetAddress (obj + fBranchOffset[i]);
          }
 
          // Read the branch.
          Int_t nb = branch->GetEntry(entry, getall);
 
          // Bookkeeping.
          if (nb < 0) {
            return nb;
          }
          nbytes += nb;
        }
 
        // End of loop over branches.
        // We just read one complete object.
        // Call the converter, if needed.
        if (fConv)
          fConv->ConvertVoid (addr, obj);
      }
 
      // End of loop over entries.  Restore @c fNdata.
      fNdata = save_ndata;
    }
  }
  else {
    // Non-container case.
    // We're reading a single object.
    // Loop over branches.
    for (Int_t i = 0; i < nbranches; ++i) {
      TBranch* branch = (TBranch*) fBranches[i];
 
      // If @c dont_reset is set, we need to propagate it to our children.
      if (dont_reset) {
        TConvertingBranchElement* be =
          dynamic_cast<TConvertingBranchElement*>(branch);
        if (!be) return -1;
        be->fConvDontReset = true;
      }
 
      // Read the branch.
      Int_t nb = branch->GetEntry(entry, getall);
 
      // Bookkeeping.
      if (nb < 0) {
        return nb;
      }
      nbytes += nb;
    }
 
    // Done reading the object.  Call the converter if needed.
    if (fConv)
      fConv->ConvertVoid (fObject, fConvObject);
  }
  return nbytes;
}

ResetAddress()

void TConvertingBranchElement::ResetAddress ( )

virtual

Reset branch addresses and maybe delete the object.

We have this here because the functionality of getting the object is disabled in standard root, for reasons which aren't entirely clear. We want to add the option to turn it on again, to prevent leaks.

Definition at line 1373 of file TConvertingBranchElement.cxx.

{
  char* object = fObject;
  char* address = fAddress;
  TBranchElement::ResetAddress();
 
  if (fgDoDel) {
    fObject = object;
    fAddress = address;
 
    // This is copied from the disabled code of TBranchElement::ReleaseObject.
    if (fID < 0) {
      // -- We are a top-level branch.
      if (fAddress && (*((char**) fAddress) != fObject)) {
        // The semantics of fAddress and fObject are violated.
        // Assume the user changed the pointer on us.
        if (TestBit(kDeleteObject)) {
          Warning("ReleaseObject", "branch: %s, You have overwritten the pointer to an object which I owned!", GetName());
          Warning("ReleaseObject", "This is a memory leak.  Please use SetAddress() to change the pointer instead.");
          ResetBit(kDeleteObject);
        }
      }
    }
 
    // Delete any object we may have allocated during a call to SetAddress.
    // (sss - added fAddress check to fix coverity warning)
    if (fAddress && fObject && TestBit(kDeleteObject)) {
      ResetBit(kDeleteObject);
      if (fType == 3) {
        // -- We are a TClonesArray master branch.
        TClonesArray::Class()->Destructor(fObject);
        fObject = 0;
        if ((fStreamerType == TVirtualStreamerInfo::kObjectp) ||
            (fStreamerType == TVirtualStreamerInfo::kObjectP)) {
          // -- We are a pointer to a TClonesArray.
          // We must zero the pointer in the object.
          *((char**) fAddress) = 0;
        }
      } else if (fType == 4) {
        // -- We are an STL container master branch.
        TVirtualCollectionProxy* proxy = GetCollectionProxy();
        if (!proxy) {
          Warning("ResetAddress", "Cannot delete allocated STL container because I do not have a proxy!  branch: %s", GetName());
          fObject = 0;
        } else {
          proxy->Destructor(fObject);
          fObject = 0;
        }
        if (fStreamerType == TVirtualStreamerInfo::kSTLp) {
          // -- We are a pointer to an STL container.
          // We must zero the pointer in the object.
          *((char**) fAddress) = 0;
        }
      } else {
        // We are *not* a TClonesArray master branch and we are *not* an STL container master branch.
        TClass* cl = fBranchClass.GetClass();
        if (!cl) {
          Warning("ResetAddress", "Cannot delete allocated object because I cannot instantiate a TClass object for its class!  branch: '%s' class: '%s'", GetName(), fBranchClass.GetClassName());
          fObject = 0;
        } else {
          cl->Destructor(fObject);
          fObject = 0;
        }
      }
    }
 
    fObject = 0;
    fAddress = 0;
  }
}

SetAddress()

void TConvertingBranchElement::SetAddress ( void * add )

virtual

Set the address of the object to use for I/O.

Parameters

add	Object address.
add	Object address.

Overridden from the base class: if we have a temporary persistent object for conversions, then we pass down the address of that object rather than what we were given.

Definition at line 1343 of file TConvertingBranchElement.cxx.

{
   TBranchElement::SetAddress (add);
   if (fConvObject) {
     Int_t nbranches = fBranches.GetEntriesFast();
     for (Int_t i = 0; i < nbranches; ++i) {
       TBranch* abranch = (TBranch*) fBranches[i];
       abranch->SetAddress(fConvObject + fBranchOffset[i]);
     }
   }
}

SetDoDel()

void TConvertingBranchElement::SetDoDel ( bool flag )

static

Set the deletion flag.

Parameters

flag	If true, try to delete the branch object on branch deletion.

Definition at line 1449 of file TConvertingBranchElement.cxx.

{
  fgDoDel = flag;
}

Streamer()

void TConvertingBranchElement::Streamer ( TBuffer & R__b )

virtual

Read or write this object.

Parameters

R__b	The Root buffer.
R__b	The Root buffer.

We wrap around the base class streamer. If we made any alterations to the persistent data members, we undo those changes here before calling the base streamer. This way the conversion handling won't change the persistent representation of the object.

Definition at line 1253 of file TConvertingBranchElement.cxx.

{
  TObjArray brsave;
  Int_t type_save = 0;
 
  if (!R__b.IsReading()) {
    if (fConvOrigType == -1)
      fConvOrigType = fType;
 
    type_save = fType;
    fType = fConvOrigType;
    if (fConvOrigBranches) {
      brsave = fBranches;
      fBranches = *fConvOrigBranches;
    }
  }
 
  TBranchElement::Streamer (R__b);
 
  if (!R__b.IsReading()) {
    fType = type_save;
    if (fConvOrigBranches) {
      fBranches = brsave;
    }
  }
}

Member Data Documentation

fConv

TVirtualConverter* TConvertingBranchElement::fConv

private

Definition at line 195 of file TConvertingBranchElement.h.

fConvClass

TClass* TConvertingBranchElement::fConvClass

private

Conversion for this branch.

Definition at line 196 of file TConvertingBranchElement.h.

fConvContainerFlag

bool TConvertingBranchElement::fConvContainerFlag

private

Saved branch type. The original.

Definition at line 208 of file TConvertingBranchElement.h.

fConvDontReset

bool TConvertingBranchElement::fConvDontReset

private

True if we're doing a container.

Definition at line 210 of file TConvertingBranchElement.h.

fConvObject

char* TConvertingBranchElement::fConvObject

private

Class for conversion.

Definition at line 197 of file TConvertingBranchElement.h.

fConvOrigBranches

TObjArray* TConvertingBranchElement::fConvOrigBranches

private

Pointer to tmp obj used for conversion.

Definition at line 198 of file TConvertingBranchElement.h.

fConvOrigType

Int_t TConvertingBranchElement::fConvOrigType

private

Saved branch list. If we change.

Definition at line 203 of file TConvertingBranchElement.h.

fgDoDel

std::atomic< bool > TConvertingBranchElement::fgDoDel = false

staticprivate

Flag that the next read should.

Definition at line 213 of file TConvertingBranchElement.h.

kIsDummy

unsigned int TConvertingBranchElement::kIsDummy = BIT(20)

staticconstexprprivate

Flag used to mark dummy nodes created by BuildConvertedElisions.

Definition at line 155 of file TConvertingBranchElement.h.

---

The documentation for this class was generated from the following files:

• TConvertingBranchElement.h
• TConvertingBranchElement.cxx