Oracle Coherence for C++ API
Release 3.6.0.0

E15728-01

WrapperCollections::AbstractWrapperSet Class Reference

#include <coherence/util/WrapperCollections.hpp>

Inherits Object, and Set.

Inherited by ConverterCollections::ConverterSet, ReadOnlyMultiList::SetView, and TypedCollections::TypedSet.

List of all members.


Detailed Description

Set implementation which delegates all calls to another Set.

Public Types

typedef spec::Handle  Handle
  AbstractWrapperSet Handle definition.
typedef spec::View  View
  AbstractWrapperSet View definition.
typedef spec::Holder  Holder
  AbstractWrapperSet Holder definition.

Public Member Functions

virtual size32_t  size () const
  Return the number of elements in this collection.
Returns:
the number of elements in this collection

virtual bool  isEmpty () const
  Determine whether this collection contains any elements.
Returns:
true if this collection has no elements

virtual bool  contains (Object::View v) const
  Determine if this collection contains the specified element.
Parameters:
v  the element to test for containment
Returns:
true iff this collection contains the given element

virtual Iterator::Handle  iterator () const
  Return an Iterator over this collection.
Returns:
an Iterator over this collection

virtual Muterator::Handle  iterator ()
  Return an Iterator over this collection.
Returns:
an Iterator over this collection

virtual
ObjectArray::Handle 
toArray (ObjectArray::Handle hao=NULL) const
  Return the contents of this collection as an ObjectArray.

If the collection fits in the specified array, it is returned, otherwise, a new array is allocated that is the size of this collection.

If this collection fits in the array with aditional room then the element in the array immediately following the end of the collection is set to NULL. This can be useful in determining the length of this collection if the caller knows that the collection does not contain any NULL elements.

Parameters:
hao  an array in which to store the collection's contents
Returns:
a ObjectArray containing all the elements of the collection in the same order as returned by the collection's Iterator
See also:
Iterator

virtual bool  add (Object::Holder oh)
  Add the given element to this collection.
Parameters:
oh  the element to add
Returns:
true iff this collection was modified as a result of this operation

virtual bool  remove (Object::View v)
  Remove the supplied element from this collection.
Parameters:
v  the element to remove
Returns:
true iff this collection was modified as a result of this operation

virtual bool  containsAll (Collection::View vc) const
  Determine if this collection contains all elements from the supplied collection.
Parameters:
vCol  the collection of elements to test for containment
Returns:
true iff this collection contains all elements from the supplied collection
Exceptions:
coherence::lang::NullPointerException  if the specified collection is NULL
See also:
contains()

virtual bool  addAll (Collection::View vc)
  Add all elements from the supplied collection to this collection.
Parameters:
vCol  the collection of elements to add
Returns:
true iff this collection was modified as a result of this operation
Exceptions:
coherence::lang::NullPointerException  if the specified collection is NULL
See also:
add()

virtual bool  removeAll (Collection::View vc)
  Remove all instances of the elements in the supplied collection from this collection.

Upon completion, contains() on this collection will return false for all elements in the supplied collection.

Parameters:
vCol  the collection of elements to remove
Returns:
true iff this collection was modified as a result of this operation
Exceptions:
coherence::lang::NullPointerException  if the specified collection is NULL
See also:
remove()

contains()


virtual bool  retainAll (Collection::View vc)
  Remove all elements from this collection that are not present in the supplied collection.
Parameters:
vCol  the collection of elements to retain
Returns:
true iff this collection was modified as a result of this operation.
Exceptions:
coherence::lang::NullPointerException  if the specified collection is NULL
See also:
remove()

contains()


virtual void  clear ()
  Remove all elements from this collection.
virtual void  toStream (std::ostream &out) const
  Output a human-readable description of this Object to the given stream.

coherence::lang::operator<<(std::ostream, Object::View) is defined and will call into the toStream method, to output Objects. If a managed String object is desired, the COH_TO_STRING macro can be used to build up a String from streamable contents.

 Object::View vKey   = ...
 Object::View vValue = ...
 std::cout << vKey << " = " << vValue << std::endl;

 String::Handle hs = COH_TO_STRING(vKey << " = " << vValue);
Parameters:
out  the stream used to output the description

virtual size32_t  hashCode () const
  Return a hash code value for the Object.

This method is supported for the benefit of hash-based containers.

The general contract of hashCode is:

  • Whenever it is invoked on the same Object more than once during an execution of an application, the hashCode method must consistently return the same value, provided no information used in equals comparisons on the object is modified. This value need not remain consistent from one execution of an application to another execution of the same application.
  • If two Objects are equal according to the equals method, then calling the hashCode method on each of the two Objects must produce the same value.
  • It is not required that if two Objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct results. However, the programmer should be aware that producing distinct results for unequal objects may improve the performance of hash-based containers.

The default implementation is identity based.

Returns:
a hash code value for this Object

virtual bool  equals (Object::View v) const
 
virtual bool  isImmutable () const
  Return true iff no further changes can be made to the Object, that would effect the outcome of a call to its equals method.

Except for Objects which are naturally immutable (such as String), being immutable generally implies that the Object is only referenced via const pointers or views. Objects which hold references to child Objects, may need to take the immutability of their children into account when determining their own immutability.

This extended check is not performed by the default implementation, but can be integrated into the immutability checks by overriding this method, as well as making use of MemberHandles to reference child Objects.

A typical derived implementation may look as follows:

 bool isImmutable() const
     {
     if (m_fImmutable) // check recorded state
         {
         return true; // already marked as immutable, avoid calculation
         }
     else if (Object::isImmutable()) // ensure shallow immutability
         {
         // ensure deep immutability
         if (m_child1->isImmutable() && m_child2->isImmutable() ...
                                     && m_childN->isImmutable())
             {
             // record and return immutability
             return m_fImmutable = true;
             }
         // some Objects which comprise this Object are still mutable
         }
     return false;
     }
 

The default implementation return true iff the Object is only referenced via const pointers and or views.

Returns:
true iff the Object is immutable


Protected Member Functions

  AbstractWrapperSet (Set::Holder ohSetDelegate)
  Create an AbstractWrapperSet which delegates to the specified Set.
  AbstractWrapperSet (const AbstractWrapperSet &that)
  Copy constructor.
virtual Set::Handle  getDelegate ()
  Return a handle to the delegate.
virtual Set::View  getDelegate () const
  Return a view to the delegate.

Constructor & Destructor Documentation

AbstractWrapperSet ( Set::Holder  ohSetDelegate  )  [protected]

Create an AbstractWrapperSet which delegates to the specified Set.

Parameters:
ohSetDelegate  the Set to delegate to

Member Function Documentation

virtual Set::Handle getDelegate (  )  [protected, virtual]

Return a handle to the delegate.

Returns:
the delegate handle
Exceptions:
UnsupportedOperationException  if the delegate is a view

virtual Set::View getDelegate (  )  const [protected, virtual]

Return a view to the delegate.

Returns:
the delegate view

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