The Tree Data Structure

{
   //
   // This macro displays the Tree data structures
   //
   gROOT.Reset();
   TCanvas *c1 = gROOT->FindObject("c1"); if (c1) c1->Delete();
   c1 = new TCanvas("c1","Tree Data Structure",200,10,700,900);
   c1->Range(0,-0.1,1,1.15);

   gBenchmark->Start("tree");

   TPaveLabel title(.3,1.05,.8,1.13,c1->GetTitle());
   title.SetFillColor(45);
   title.Draw();
   TPaveText tree(.01,.75,.15,1.00);
   tree.SetFillColor(18);
   tree.SetTextAlign(12);
   TText *tnt = tree.AddText("Tree");
   tnt.SetTextAlign(22);
   tnt.SetTextSize(0.030);
   tree.AddText("fScanField");
   tree.AddText("fMaxEventLoop");
   tree.AddText("fMaxVirtualSize");
   tree.AddText("fEntries");
   tree.AddText("fDimension");
   tree.AddText("fSelectedRows");
   tree.Draw();
   TPavesText farm(.01,1.02,.15,1.1,9,"tr");
   TText *tfarm = farm.AddText("FARM");
   tfarm.SetTextSize(0.024);
   farm.AddText("Collection");
   farm.AddText("of Trees");
   farm.Draw();
   TLine link(.15,.92,.80,.92);
   link.SetLineWidth(2);
   link.SetLineColor(1);
   link.Draw();
   link.DrawLine(.21,.87,.21,.275);
   link.DrawLine(.23,.87,.23,.375);
   link.DrawLine(.25,.87,.25,.775);
   link.DrawLine(.41,.25,.41,-.025);
   link.DrawLine(.43,.25,.43,.075);
   link.DrawLine(.45,.25,.45,.175);
   TPaveLabel branch0(.20,.87,.35,.97,"Branch 0");
   branch0.SetFillColor(49);
   branch0.Draw();
   TPaveLabel branch1(.40,.87,.55,.97,"Branch 1");
   branch1.SetFillColor(49);
   branch1.Draw();
   TPaveLabel branch2(.60,.87,.75,.97,"Branch 2");
   branch2.SetFillColor(49);
   branch2.Draw();
   TPaveLabel branch3(.80,.87,.95,.97,"Branch 3");
   branch3.SetFillColor(49);
   branch3.Draw();
   TPaveLabel leaf0(.4,.75,.5,.8,"Leaf 0");
   leaf0.SetFillColor(38);
   leaf0.Draw();
   TPaveLabel leaf1(.6,.75,.7,.8,"Leaf 1");
   leaf1.SetFillColor(38);
   leaf1.Draw();
   TPaveLabel leaf2(.8,.75,.9,.8,"Leaf 2");
   leaf2.SetFillColor(38);
   leaf2.Draw();
   TPaveText firstevent(.4,.35,.9,.4);
   firstevent.AddText("First event of each basket");
   firstevent.AddText("Array of fMaxBaskets Integers");
   firstevent.SetFillColor(24);
   firstevent.Draw();
   TPaveLabel basket0(.4,.25,.5,.3,"Basket 0");
   basket0.SetFillColor(24);
   basket0.Draw();
   TPaveLabel basket1(.6,.25,.7,.3,"Basket 1");
   basket1.SetFillColor(24);
   basket1.Draw();
   TPaveLabel basket2(.8,.25,.9,.3,"Basket 2");
   basket2.SetFillColor(24);
   basket2.Draw();

   TPaveText offset(.55,.15,.9,.2);
   offset.AddText("Offset of events in fBuffer");
   offset.AddText("Array of fEventOffsetLen Integers");
   offset.AddText("(if variable length structure)");
   offset.SetFillColor(28);
   offset.Draw();
   TPaveText buffer(.55,.05,.9,.1);
   buffer.AddText("Basket buffer");
   buffer.AddText("Array of fBasketSize chars");
   buffer.SetFillColor(28);
   buffer.Draw();
   TPaveText zipbuffer(.55,-.05,.75,.0);
   zipbuffer.AddText("Basket compressed buffer");
   zipbuffer.AddText("(if compression)");
   zipbuffer.SetFillColor(28);
   zipbuffer.Draw();
   TArrow ar1;
   ar1.SetLineWidth(2);
   ar1.SetLineColor(1);
   ar1.SetFillStyle(1001);
   ar1.SetFillColor(1);
   ar1.DrawArrow(.21,.275,.39,.275,0.015,"|>");
   ar1.DrawArrow(.23,.375,.39,.375,0.015,"|>");
   ar1.DrawArrow(.25,.775,.39,.775,0.015,"|>");
   ar1.DrawArrow(.50,.775,.59,.775,0.015,"|>");
   ar1.DrawArrow(.70,.775,.79,.775,0.015,"|>");
   ar1.DrawArrow(.50,.275,.59,.275,0.015,"|>");
   ar1.DrawArrow(.70,.275,.79,.275,0.015,"|>");
   ar1.DrawArrow(.45,.175,.54,.175,0.015,"|>");
   ar1.DrawArrow(.43,.075,.54,.075,0.015,"|>");
   ar1.DrawArrow(.41,-.025,.54,-.025,0.015,"|>");
   TLine ldot(.95,.92,.99,.92);
   ldot.SetLineStyle(3);
   ldot.Draw();
   ldot.DrawLine(.9,.775,.99,.775);
   ldot.DrawLine(.9,.275,.99,.275);
   ldot.DrawLine(.55,.05,.55,0);
   ldot.DrawLine(.9,.05,.75,0);
   TText pname(.46,.21,"fEventOffset");
   pname.SetTextFont(72);
   pname.SetTextSize(0.018);
   pname.Draw();
   pname.DrawText(.44,.11,"fBuffer");
   pname.DrawText(.42,.01,"fZipBuffer");
   pname.DrawText(.26,.81,"fLeaves = TObjArray of TLeaf");
   pname.DrawText(.24,.40,"fBasketEvent");
   pname.DrawText(.22,.31,"fBaskets = TObjArray of TBasket");
   pname.DrawText(.20,1.0,"fBranches = TObjArray of TBranch");
   TPaveText ntleaf(0.30,.42,.6,.7);
   ntleaf.SetFillColor(38);
   ntleaf.SetTextAlign(12);
   ntleaf.AddText("fLen: number of fixed elements");
   ntleaf.AddText("fLenType: number of bytes of data type");
   ntleaf.AddText("fOffset: relative to Leaf0-fAddress");
   ntleaf.AddText("fNbytesIO: number of bytes used for I/O");
   ntleaf.AddText("fIsPointer: True if pointer");
   ntleaf.AddText("fIsRange: True if leaf has a range");
   ntleaf.AddText("fIsUnsigned: True if unsigned");
   ntleaf.AddText("*fLeafCount: points to Leaf count if variable");
   ntleaf.AddText(" ");
   ntleaf.AddLine(0,0,0,0);
   ntleaf.AddText("fName = Leaf name");
   ntleaf.AddText("fTitle = Leaf type (see Type codes)");
   ntleaf.Draw();
   TPaveText type(.65,.42,.95,.7);
   type.SetTextAlign(12);
   type.SetFillColor(38);
   type.AddText(" ");
   type.AddText("C : a character string");
   type.AddText("B : an 8 bit signed integer");
   type.AddText("b : an 8 bit unsigned integer");
   type.AddText("S : a 16 bit signed short integer");
   type.AddText("s : a 16 bit unsigned short integer");
   type.AddText("I : a 32 bit signed integer");
   type.AddText("i : a 32 bit unsigned integer");
   type.AddText("F : a 32 bit floating point");
   type.AddText("D : a 64 bit floating point");
   type.AddText("TXXXX : a class name TXXXX");
   type.Draw();
   TPaveLabel typecode(.7,.68,.9,.72,"fType codes");
   typecode.SetFillColor(38);
   typecode.Draw();
   ldot.DrawLine(.4,.75,.30,.7);
   ldot.DrawLine(.5,.75,.6,.7);
   TPaveText ntbasket(0.02,-0.07,0.35,.25);
   ntbasket.SetFillColor(24);
   ntbasket.SetTextAlign(12);
   ntbasket.AddText("fNbytes: Size of compressed Basket");
   ntbasket.AddText("fObjLen: Size of uncompressed Basket");
   ntbasket.AddText("fDatime: Date/Time when written to store");
   ntbasket.AddText("fKeylen: Number of bytes for the key");
   ntbasket.AddText("fCycle : Cycle number");
   ntbasket.AddText("fSeekKey: Pointer to Basket on file");
   ntbasket.AddText("fSeekPdir: Pointer to directory on file");
   ntbasket.AddText("fClassName: 'TBasket'");
   ntbasket.AddText("fName: Branch name");
   ntbasket.AddText("fTitle: Tree name");
   ntbasket.AddText(" ");
   ntbasket.AddLine(0,0,0,0);
   ntbasket.AddText("fNevBuf: Number of events in Basket");
   ntbasket.AddText("fLast: pointer to last used byte in Basket");
   ntbasket.Draw();
   ldot.DrawLine(.4,.3,0.02,0.25);
   ldot.DrawLine(.5,.25,0.35,-.07);
   ldot.DrawLine(.5,.3,0.35,0.25);
   TPaveText ntbranch(0.02,0.40,0.18,0.68);
   ntbranch.SetFillColor(49);
   ntbranch.SetTextAlign(12);
   ntbranch.AddText("fBasketSize");
   ntbranch.AddText("fEventOffsetLen");
   ntbranch.AddText("fMaxBaskets");
   ntbranch.AddText("fEntries");
   ntbranch.AddText("fAddress of Leaf0");
   ntbranch.AddText(" ");
   ntbranch.AddLine(0,0,0,0);
   ntbranch.AddText("fName = Branch name");
   ntbranch.AddText("fTitle = leaflist");
   ntbranch.Draw();
   ldot.DrawLine(.2,.97,.02,.68);
   ldot.DrawLine(.35,.97,.18,.68);
   ldot.DrawLine(.35,.87,.18,.40);
   TPavesText basketstore(.8,-0.088,0.952,-0.0035,7,"tr");
   basketstore.SetFillColor(24);
   basketstore.AddText("Baskets");
   basketstore.AddText("Stores");
   basketstore.Draw();
   c1->Update();

   gBenchmark->Show("tree");
}