THashTable implements a hash table to store TObject's.
The hash value is calculated using the value returned by the TObject's Hash() function. Each class inheriting from TObject can override Hash() as it sees fit.
THashTable does not preserve the insertion order of the objects. If the insertion order is important AND fast retrieval is needed use THashList instead.
Definition at line 35 of file THashTable.h.
Public Member Functions | |
THashTable (Int_t capacity=TCollection::kInitHashTableCapacity, Int_t rehash=0) | |
Create a THashTable object. | |
virtual | ~THashTable () |
Delete a hashtable. | |
void | Add (TObject *obj) |
Add object to the hash table. | |
virtual void | AddAll (const TCollection *col) |
Add all objects from collection col to this collection. | |
void | AddBefore (const TObject *before, TObject *obj) |
Add object to the hash table. | |
Float_t | AverageCollisions () const |
void | Clear (Option_t *option="") |
Remove all objects from the table. | |
Int_t | Collisions (const char *name) const |
Returns the number of collisions for an object with a certain name (i.e. | |
Int_t | Collisions (TObject *obj) const |
Returns the number of collisions for an object (i.e. | |
void | Delete (Option_t *option="") |
Remove all objects from the table AND delete all heap based objects. | |
Bool_t | Empty () const |
TObject * | FindObject (const char *name) const |
Find object using its name. | |
TObject * | FindObject (const TObject *obj) const |
Find object using its hash value (returned by its Hash() member). | |
const TList * | GetListForObject (const char *name) const |
Return the TList corresponding to object's name based hash value. | |
const TList * | GetListForObject (const TObject *obj) const |
Return the TList corresponding to object's hash value. | |
TObject ** | GetObjectRef (const TObject *obj) const |
Return address of pointer to obj. | |
Int_t | GetRehashLevel () const |
Int_t | GetSize () const |
Return the capacity of the collection, i.e. | |
TIterator * | MakeIterator (Bool_t dir=kIterForward) const |
Returns a hash table iterator. | |
virtual void | Print (Option_t *option, const char *wildcard, Int_t recurse=1) const |
Print the collection header and its elements that match the wildcard. | |
void | Print (Option_t *option, Int_t recurse) const |
Print the collection header and its elements. | |
virtual void | Print (Option_t *option, Int_t recurse) const |
Print the collection header and its elements. | |
virtual void | Print (Option_t *option, TPRegexp ®exp, Int_t recurse=1) const |
Print the collection header and its elements that match the regexp. | |
virtual void | Print (Option_t *option="") const |
Default print for collections, calls Print(option, 1). | |
void | Rehash (Int_t newCapacity, Bool_t checkObjValidity=kTRUE) |
Rehash the hashtable. | |
TObject * | Remove (TObject *obj) |
Remove object from the hashtable. | |
TObject * | RemoveSlow (TObject *obj) |
Remove object from the hashtable without using the hash value. | |
void | SetRehashLevel (Int_t rehash) |
Public Member Functions inherited from TCollection | |
virtual | ~TCollection () |
TNamed destructor. | |
void | AddVector (TObject *obj1,...) |
Add all arguments to the collection. | |
Bool_t | AssertClass (TClass *cl) const |
Make sure all objects in this collection inherit from class cl. | |
TIter | begin () const |
void | Browse (TBrowser *b) |
Browse this collection (called by TBrowser). | |
Int_t | Capacity () const |
virtual TObject * | Clone (const char *newname="") const |
Make a clone of an collection using the Streamer facility. | |
Int_t | Compare (const TObject *obj) const |
Compare two TCollection objects. | |
Bool_t | Contains (const char *name) const |
Bool_t | Contains (const TObject *obj) const |
virtual void | Draw (Option_t *option="") |
Draw all objects in this collection. | |
virtual void | Dump () const |
Dump all objects in this collection. | |
TIter | end () const |
virtual Int_t | GetEntries () const |
virtual const char * | GetName () const |
Return name of this collection. | |
virtual Int_t | GrowBy (Int_t delta) const |
Increase the collection's capacity by delta slots. | |
ULong_t | Hash () const |
Return hash value for this object. | |
Bool_t | IsArgNull (const char *where, const TObject *obj) const |
Returns true if object is a null pointer. | |
virtual Bool_t | IsEmpty () const |
virtual Bool_t | IsFolder () const |
Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). | |
Bool_t | IsOwner () const |
Bool_t | IsSortable () const |
R__ALWAYS_INLINE Bool_t | IsUsingRWLock () const |
virtual void | ls (Option_t *option="") const |
List (ls) all objects in this collection. | |
virtual TIterator * | MakeReverseIterator () const |
virtual Bool_t | Notify () |
'Notify' all objects in this collection. | |
TObject * | operator() (const char *name) const |
Find an object in this collection by name. | |
virtual void | Paint (Option_t *option="") |
Paint all objects in this collection. | |
virtual void | RecursiveRemove (TObject *obj) |
Remove object from this collection and recursively remove the object from all other objects (and collections). | |
void | RemoveAll () |
virtual void | RemoveAll (TCollection *col) |
Remove all objects in collection col from this collection. | |
void | SetCurrentCollection () |
Set this collection to be the globally accessible collection. | |
void | SetName (const char *name) |
virtual void | SetOwner (Bool_t enable=kTRUE) |
Set whether this collection is the owner (enable==true) of its content. | |
virtual bool | UseRWLock (Bool_t enable=true) |
Set this collection to use a RW lock upon access, making it thread safe. | |
virtual Int_t | Write (const char *name=0, Int_t option=0, Int_t bufsize=0) |
Write all objects in this collection. | |
virtual Int_t | Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const |
Write all objects in this collection. | |
Public Member Functions inherited from TObject | |
TObject () | |
TObject constructor. | |
TObject (const TObject &object) | |
TObject copy ctor. | |
virtual | ~TObject () |
TObject destructor. | |
void | AbstractMethod (const char *method) const |
Use this method to implement an "abstract" method that you don't want to leave purely abstract. | |
virtual void | AppendPad (Option_t *option="") |
Append graphics object to current pad. | |
ULong_t | CheckedHash () |
Check and record whether this class has a consistent Hash/RecursiveRemove setup (*) and then return the regular Hash value for this object. | |
virtual const char * | ClassName () const |
Returns name of class to which the object belongs. | |
virtual void | Copy (TObject &object) const |
Copy this to obj. | |
virtual Int_t | DistancetoPrimitive (Int_t px, Int_t py) |
Computes distance from point (px,py) to the object. | |
virtual void | DrawClass () const |
Draw class inheritance tree of the class to which this object belongs. | |
virtual TObject * | DrawClone (Option_t *option="") const |
Draw a clone of this object in the current selected pad for instance with: gROOT->SetSelectedPad(gPad) . | |
virtual void | Error (const char *method, const char *msgfmt,...) const |
Issue error message. | |
virtual void | Execute (const char *method, const char *params, Int_t *error=0) |
Execute method on this object with the given parameter string, e.g. | |
virtual void | Execute (TMethod *method, TObjArray *params, Int_t *error=0) |
Execute method on this object with parameters stored in the TObjArray. | |
virtual void | ExecuteEvent (Int_t event, Int_t px, Int_t py) |
Execute action corresponding to an event at (px,py). | |
virtual void | Fatal (const char *method, const char *msgfmt,...) const |
Issue fatal error message. | |
virtual Option_t * | GetDrawOption () const |
Get option used by the graphics system to draw this object. | |
virtual const char * | GetIconName () const |
Returns mime type name of object. | |
virtual char * | GetObjectInfo (Int_t px, Int_t py) const |
Returns string containing info about the object at position (px,py). | |
virtual Option_t * | GetOption () const |
virtual const char * | GetTitle () const |
Returns title of object. | |
virtual UInt_t | GetUniqueID () const |
Return the unique object id. | |
virtual Bool_t | HandleTimer (TTimer *timer) |
Execute action in response of a timer timing out. | |
Bool_t | HasInconsistentHash () const |
Return true is the type of this object is known to have an inconsistent setup for Hash and RecursiveRemove (i.e. | |
virtual void | Info (const char *method, const char *msgfmt,...) const |
Issue info message. | |
virtual Bool_t | InheritsFrom (const char *classname) const |
Returns kTRUE if object inherits from class "classname". | |
virtual Bool_t | InheritsFrom (const TClass *cl) const |
Returns kTRUE if object inherits from TClass cl. | |
virtual void | Inspect () const |
Dump contents of this object in a graphics canvas. | |
void | InvertBit (UInt_t f) |
Bool_t | IsDestructed () const |
IsDestructed. | |
virtual Bool_t | IsEqual (const TObject *obj) const |
Default equal comparison (objects are equal if they have the same address in memory). | |
R__ALWAYS_INLINE Bool_t | IsOnHeap () const |
R__ALWAYS_INLINE Bool_t | IsZombie () const |
void | MayNotUse (const char *method) const |
Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary). | |
void | Obsolete (const char *method, const char *asOfVers, const char *removedFromVers) const |
Use this method to declare a method obsolete. | |
void | operator delete (void *ptr) |
Operator delete. | |
void | operator delete[] (void *ptr) |
Operator delete []. | |
void * | operator new (size_t sz) |
void * | operator new (size_t sz, void *vp) |
void * | operator new[] (size_t sz) |
void * | operator new[] (size_t sz, void *vp) |
TObject & | operator= (const TObject &rhs) |
TObject assignment operator. | |
virtual void | Pop () |
Pop on object drawn in a pad to the top of the display list. | |
virtual Int_t | Read (const char *name) |
Read contents of object with specified name from the current directory. | |
void | ResetBit (UInt_t f) |
virtual void | SaveAs (const char *filename="", Option_t *option="") const |
Save this object in the file specified by filename. | |
virtual void | SavePrimitive (std::ostream &out, Option_t *option="") |
Save a primitive as a C++ statement(s) on output stream "out". | |
void | SetBit (UInt_t f) |
void | SetBit (UInt_t f, Bool_t set) |
Set or unset the user status bits as specified in f. | |
virtual void | SetDrawOption (Option_t *option="") |
Set drawing option for object. | |
virtual void | SetUniqueID (UInt_t uid) |
Set the unique object id. | |
virtual void | SysError (const char *method, const char *msgfmt,...) const |
Issue system error message. | |
R__ALWAYS_INLINE Bool_t | TestBit (UInt_t f) const |
Int_t | TestBits (UInt_t f) const |
virtual void | UseCurrentStyle () |
Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked. | |
virtual void | Warning (const char *method, const char *msgfmt,...) const |
Issue warning message. | |
Private Member Functions | |
THashTable (const THashTable &)=delete | |
void | AddImpl (Int_t slot, TObject *object) |
Helper function doing the actual add to the table give a slot and object. | |
Int_t | GetCheckedHashValue (TObject *obj) const |
Int_t | GetHashValue (const char *str) const |
Int_t | GetHashValue (const TObject *obj) const |
Int_t | GetHashValue (TString &s) const |
THashTable & | operator= (const THashTable &)=delete |
Private Attributes | |
TList ** | fCont |
Int_t | fEntries |
Int_t | fRehashLevel |
Int_t | fUsedSlots |
Friends | |
class | THashTableIter |
Additional Inherited Members | |
Public Types inherited from TCollection | |
enum | { kInitCapacity = 16 , kInitHashTableCapacity = 17 } |
Public Types inherited from TObject | |
enum | { kIsOnHeap = 0x01000000 , kNotDeleted = 0x02000000 , kZombie = 0x04000000 , kInconsistent = 0x08000000 , kBitMask = 0x00ffffff } |
enum | { kSingleKey = BIT(0) , kOverwrite = BIT(1) , kWriteDelete = BIT(2) } |
enum | EDeprecatedStatusBits { kObjInCanvas = BIT(3) } |
enum | EStatusBits { kCanDelete = BIT(0) , kMustCleanup = BIT(3) , kIsReferenced = BIT(4) , kHasUUID = BIT(5) , kCannotPick = BIT(6) , kNoContextMenu = BIT(8) , kInvalidObject = BIT(13) } |
Static Public Member Functions inherited from TCollection | |
static void | EmptyGarbageCollection () |
Do the garbage collection. | |
static void | GarbageCollect (TObject *obj) |
Add to the list of things to be cleaned up. | |
static TCollection * | GetCurrentCollection () |
Return the globally accessible collection. | |
static void | StartGarbageCollection () |
Set up for garbage collection. | |
Static Public Member Functions inherited from TObject | |
static Longptr_t | GetDtorOnly () |
Return destructor only flag. | |
static Bool_t | GetObjectStat () |
Get status of object stat flag. | |
static void | SetDtorOnly (void *obj) |
Set destructor only flag. | |
static void | SetObjectStat (Bool_t stat) |
Turn on/off tracking of objects in the TObjectTable. | |
Protected Types inherited from TCollection | |
enum | EStatusBits { kIsOwner = BIT(14) , kUseRWLock = BIT(16) } |
Protected Types inherited from TObject | |
enum | { kOnlyPrepStep = BIT(3) } |
Protected Member Functions inherited from TCollection | |
TCollection () | |
virtual const char * | GetCollectionEntryName (TObject *entry) const |
For given collection entry return the string that is used to identify the object and, potentially, perform wildcard/regexp filtering on. | |
virtual void | PrintCollectionEntry (TObject *entry, Option_t *option, Int_t recurse) const |
Print the collection entry. | |
virtual void | PrintCollectionHeader (Option_t *option) const |
Print the collection header. | |
Protected Member Functions inherited from TObject | |
virtual void | DoError (int level, const char *location, const char *fmt, va_list va) const |
Interface to ErrorHandler (protected). | |
void | MakeZombie () |
Protected Attributes inherited from TCollection | |
TString | fName |
Int_t | fSize |
#include <THashTable.h>
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THashTable::THashTable | ( | Int_t | capacity = TCollection::kInitHashTableCapacity , |
Int_t | rehashlevel = 0 |
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) |
Create a THashTable object.
Capacity is the initial hashtable capacity (i.e. number of slots), by default kInitHashTableCapacity = 17, and rehashlevel is the value at which a rehash will be triggered. I.e. when the average size of the linked lists at a slot becomes longer than rehashlevel then the hashtable will be resized and refilled to reduce the collision rate to about 1. The higher the collision rate, i.e. the longer the linked lists, the longer lookup will take. If rehashlevel=0 the table will NOT automatically be rehashed. Use Rehash() for manual rehashing.
Definition at line 43 of file THashTable.cxx.
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Delete a hashtable.
Objects are not deleted unless the THashTable is the owner (set via SetOwner()).
Definition at line 65 of file THashTable.cxx.
Add object to the hash table.
Its position in the table will be determined by the value returned by its Hash() function.
Implements TCollection.
Definition at line 92 of file THashTable.cxx.
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virtual |
Add all objects from collection col to this collection.
Implemented for more efficient rehashing.
Reimplemented from TCollection.
Definition at line 138 of file THashTable.cxx.
Add object to the hash table.
Its position in the table will be determined by the value returned by its Hash() function. If and only if 'before' is in the same bucket as obj, obj is added in front of 'before' within the bucket's list.
Definition at line 112 of file THashTable.cxx.
Helper function doing the actual add to the table give a slot and object.
This does not take any lock.
Definition at line 78 of file THashTable.cxx.
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inline |
Definition at line 85 of file THashTable.h.
Remove all objects from the table.
Does not delete the objects unless the THashTable is the owner (set via SetOwner()).
Implements TCollection.
Definition at line 167 of file THashTable.cxx.
Int_t THashTable::Collisions | ( | const char * | name | ) | const |
Returns the number of collisions for an object with a certain name (i.e.
number of objects in same slot in the hash table, i.e. length of linked list).
Definition at line 191 of file THashTable.cxx.
Returns the number of collisions for an object (i.e.
number of objects in same slot in the hash table, i.e. length of linked list).
Definition at line 205 of file THashTable.cxx.
Remove all objects from the table AND delete all heap based objects.
Implements TCollection.
Definition at line 220 of file THashTable.cxx.
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inline |
Definition at line 66 of file THashTable.h.
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virtual |
Find object using its name.
Uses the hash value returned by the TString::Hash() after converting name to a TString.
Reimplemented from TCollection.
Reimplemented in TListOfTypes, and TListOfTypes.
Definition at line 238 of file THashTable.cxx.
Find object using its hash value (returned by its Hash() member).
Reimplemented from TCollection.
Reimplemented in TListOfTypes.
Definition at line 251 of file THashTable.cxx.
Definition at line 93 of file THashTable.h.
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inlineprivate |
Definition at line 48 of file THashTable.h.
Definition at line 99 of file THashTable.h.
Definition at line 47 of file THashTable.h.
const TList * THashTable::GetListForObject | ( | const char * | name | ) | const |
Return the TList corresponding to object's name based hash value.
One can iterate this list "manually" to find, e.g. objects with the same name.
Definition at line 268 of file THashTable.cxx.
Return the TList corresponding to object's hash value.
One can iterate this list "manually" to find, e.g. identical objects.
Definition at line 282 of file THashTable.cxx.
Return address of pointer to obj.
Implements TCollection.
Definition at line 296 of file THashTable.cxx.
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inline |
Definition at line 72 of file THashTable.h.
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inlinevirtual |
Return the capacity of the collection, i.e.
the current total amount of space that has been allocated so far. Same as Capacity
. Use GetEntries
to get the number of elements currently in the collection.
Reimplemented from TCollection.
Definition at line 73 of file THashTable.h.
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virtual |
Returns a hash table iterator.
Implements TCollection.
Definition at line 311 of file THashTable.cxx.
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privatedelete |
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virtual |
Print the collection header and its elements that match the wildcard.
If recurse is non-zero, descend into printing of collection-entries with recurse - 1. This means, if recurse is negative, the recursion is infinite.
Option is passed recursively, but wildcard is only used on the first level.
Reimplemented from TCollection.
Definition at line 199 of file TCollection.cxx.
Print the collection header and its elements.
If recurse is non-zero, descend into printing of collection-entries with recurse - 1. This means, if recurse is negative, the recursion is infinite.
If option contains "details", Print will show the content of each of the hash-slots.
Option is passed recursively.
Reimplemented from TCollection.
Definition at line 328 of file THashTable.cxx.
Print the collection header and its elements.
If recurse is non-zero, descend into printing of collection-entries with recurse - 1. This means, if recurse is negative, the recursion is infinite.
Option is passed recursively.
Reimplemented from TCollection.
Definition at line 198 of file TCollection.cxx.
Print the collection header and its elements that match the regexp.
If recurse is non-zero, descend into printing of collection-entries with recurse - 1. This means, if recurse is negative, the recursion is infinite.
Option is passed recursively, but regexp is only used on the first level.
Reimplemented from TCollection.
Definition at line 200 of file TCollection.cxx.
Default print for collections, calls Print(option, 1).
This will print the collection header and Print() methods of all the collection entries.
If you want to override Print() for a collection class, first see if you can accomplish it by overriding the following protected methods:
Otherwise override the Print(Option_t *option, Int_t)
variant. Remember to declare:
somewhere close to the method declaration.
Reimplemented from TCollection.
Definition at line 197 of file TCollection.cxx.
Rehash the hashtable.
If the collision rate becomes too high (i.e. the average size of the linked lists become too long) then lookup efficiency decreases since relatively long lists have to be searched every time. To improve performance rehash the hashtable. This resizes the table to newCapacity slots and refills the table. Use AverageCollisions() to check if you need to rehash. Set checkObjValidity to kFALSE if you know that all objects in the table are still valid (i.e. have not been deleted from the system in the meanwhile).
Definition at line 365 of file THashTable.cxx.
Remove object from the hashtable.
Implements TCollection.
Definition at line 417 of file THashTable.cxx.
Remove object from the hashtable without using the hash value.
Definition at line 442 of file THashTable.cxx.
Definition at line 80 of file THashTable.h.
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friend |
Definition at line 37 of file THashTable.h.
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private |
Definition at line 40 of file THashTable.h.
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private |
Definition at line 41 of file THashTable.h.
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private |
Definition at line 43 of file THashTable.h.
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private |
Definition at line 42 of file THashTable.h.