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ROOT
Reference Guide |
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ROOT
Reference Guide |
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An interface for reading values stored in ROOT columnar datasets.
The TTreeReaderValue is a type-safe tool to be used in association with a TTreeReader to access the values stored in TTree, TNtuple and TChain datasets. TTreeReaderValue can be also used to access collections such as std::vectors or TClonesArray stored in columnar datasets but it is recommended to use TTreeReaderArray instead as it offers several advantages.
See the documentation of TTreeReader for more details and examples.
Definition at line 174 of file TTreeReaderValue.h.
Public Types | |
| using | NonConstT_t = typename std::remove_const< T >::type |
 Public Types inherited from ROOT::Internal::TTreeReaderValueBase | |
| typedef bool(ROOT::Detail::TBranchProxy::* | BranchProxyRead_t) () |
| enum | EReadStatus { kReadSuccess = 0 , kReadNothingYet , kReadError } |
| enum | ESetupStatus { kSetupNotSetup = -7 , kSetupTreeDestructed = -8 , kSetupMakeClassModeMismatch = -9 , kSetupMissingCounterBranch = -6 , kSetupMissingBranch = -5 , kSetupInternalError = -4 , kSetupMissingDictionary = -3 , kSetupMismatch = -2 , kSetupNotACollection = -1 , kSetupMatch = 0 , kSetupMatchBranch = 7 , kSetupNoCheck = 5 , kSetupMatchLeaf = 6 } |
| Status flags, 0 is good. More... | |
Public Member Functions | |
| TTreeReaderValue ()=delete | |
| TTreeReaderValue (TTreeReader &tr, const char *branchname) | |
| T * | Get () |
| Return a pointer to the value of the current entry. | |
| T & | operator* () |
| Return a reference to the value of the current entry. | |
| T * | operator-> () |
| Return a pointer to the value of the current entry. | |
| Public Member Functions inherited from ROOT::Internal::TTreeReaderValueBase | |
| virtual | ~TTreeReaderValueBase () |
| Unregister from tree reader, cleanup. | |
| void * | GetAddress () |
| Returns the memory address of the object being read. | |
| const char * | GetBranchName () const |
| TLeaf * | GetLeaf () |
| If we are reading a leaf, return the corresponding TLeaf. | |
| virtual EReadStatus | GetReadStatus () const |
| ESetupStatus | GetSetupStatus () const |
| Return this TTreeReaderValue's setup status. | |
| bool | IsValid () const |
| Return true if the branch was setup and read correctly. | |
| EReadStatus | ProxyRead () |
| EReadStatus | ProxyReadDefaultImpl () |
| template<BranchProxyRead_t Func> | |
| ROOT::Internal::TTreeReaderValueBase::EReadStatus | ProxyReadTemplate () |
| Try to read the value from the TBranchProxy, returns the status of the read. | |
Protected Member Functions | |
| const char * | GetDerivedTypeName () const override |
| Get the template argument as a string. | |
| Protected Member Functions inherited from ROOT::Internal::TTreeReaderValueBase | |
| TTreeReaderValueBase (const TTreeReaderValueBase &) | |
| Copy-construct. | |
| TTreeReaderValueBase (TTreeReader *reader, const char *branchname, TDictionary *dict, bool opaqueRead=false) | |
| Construct a tree value reader and register it with the reader object. | |
| virtual void | CreateProxy () |
| Create the proxy object for our branch. | |
| void | ErrorAboutMissingProxyIfNeeded () |
| Detail::TBranchProxy * | GetProxy () const |
| void | MarkTreeReaderUnavailable () |
| void | NotifyNewTree (TTree *newTree) |
| The TTreeReader has switched to a new TTree. Update the leaf. | |
| TTreeReaderValueBase & | operator= (const TTreeReaderValueBase &) |
| Copy-assign. | |
| void | RegisterWithTreeReader () |
| Register with tree reader. | |
| TBranch * | SearchBranchWithCompositeName (TLeaf *&myleaf, TDictionary *&branchActualType, std::string &err) |
| Search a branch the name of which contains a ".". | |
Additional Inherited Members | |
| Protected Types inherited from ROOT::Internal::TTreeReaderValueBase | |
| typedef EReadStatus(TTreeReaderValueBase::* | Read_t) () |
| Static Protected Member Functions inherited from ROOT::Internal::TTreeReaderValueBase | |
| static const char * | GetBranchDataType (TBranch *branch, TDictionary *&dict, TDictionary const *curDict) |
| Retrieve the type of data stored by branch; put its dictionary into dict, return its type name. | |
| static std::string | GetElementTypeName (const std::type_info &ti) |
| Stringify the template argument. | |
| Protected Attributes inherited from ROOT::Internal::TTreeReaderValueBase | |
| TString | fBranchName |
| Name of the branch to read data from. | |
| TDictionary * | fDict |
| Type that the branch should contain. | |
| bool | fHaveLeaf: 1 |
| Whether the data is in a leaf. | |
| bool | fHaveStaticClassOffsets: 1 |
| Whether !fStaticClassOffsets.empty() | |
| TLeaf * | fLeaf = nullptr |
| TString | fLeafName |
| bool | fOpaqueRead {false} |
| If true, the reader will not do any type-checking against the actual type held by the branch. | |
| Detail::TBranchProxy * | fProxy = nullptr |
| Proxy for this branch, owned by TTreeReader. | |
| Read_t | fProxyReadFunc = &TTreeReaderValueBase::ProxyReadDefaultImpl |
| ! Pointer to the Read implementation to use. | |
| EReadStatus | fReadStatus: 2 |
| Read status of this data access. | |
| ESetupStatus | fSetupStatus = kSetupNotSetup |
| Setup status of this data access. | |
| std::vector< Long64_t > | fStaticClassOffsets |
| TTreeReader * | fTreeReader |
| Tree reader we belong to. | |
#include <TTreeReaderValue.h>
| using TTreeReaderValue< T >::NonConstT_t = typename std::remove_const<T>::type |
Definition at line 178 of file TTreeReaderValue.h.
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delete |
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inline |
Definition at line 180 of file TTreeReaderValue.h.
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inline |
Return a pointer to the value of the current entry.
Return a nullptr and print an error if no entry has been loaded yet. The returned address is guaranteed to stay constant while a given TTree is being read from a given file, unless the branch addresses are manipulated directly (e.g. through TTree::SetBranchAddress()). The address might also change when the underlying TTree/TFile is switched, e.g. when a TChain switches files.
Definition at line 189 of file TTreeReaderValue.h.
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inlineoverrideprotectedvirtual |
Get the template argument as a string.
Implements ROOT::Internal::TTreeReaderValueBase.
Definition at line 211 of file TTreeReaderValue.h.
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inline |
Return a reference to the value of the current entry.
Equivalent to dereferencing the pointer returned by Get(). Behavior is undefined if no entry has been loaded yet. Most likely a crash will occur.
Definition at line 206 of file TTreeReaderValue.h.
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inline |
Return a pointer to the value of the current entry.
Equivalent to Get().
Definition at line 201 of file TTreeReaderValue.h.
