Oracle Coherence for C++ API
Release 3.7.1.0
E22845-01

coherence::util::SafeHashMap::Entry

SafeHashMap::Entry Class Reference

#include <coherence/util/SafeHashMap.hpp>

Inherits Object.

List of all members.

Detailed Description

A map entry (key-value pair).

The Map.entrySet method returns a collection-view of the map, whose elements are of this class.

 

Public Types
typedef spec::Handle  Handle
  Entry Handle definition.
typedef spec::View  View
  Entry View definition.
typedef spec::Holder  Holder
  Entry Holder definition.

Public Member Functions
virtual bool  isKeyEqual (Object::View vKey) const
  Return true if the supplied key is equal to the entries key.
virtual Object::View  getKey () const
   
virtual Object::Holder  getValue () const
   
virtual Object::Holder  getValue ()
   
virtual Object::Holder  setValue (Object::Holder ohValue)
   
virtual void  onAdd ()
  This method is invoked when the containing Map has actually added this Entry to itself.
virtual bool  equals (Object::View vThat) const
   
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 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

Protected Member Functions
  Entry (Object::View vKey, Object::Holder ohValue, size32_t nHash)
  Create a new Map::Entry.
  Entry (const Entry &that)
  Copy Constructor.
  Entry (Entry::View vThat)
  Instantiate an Entry shallow copying the key and value from the Entry provided.

Protected Attributes
FinalView< Object >  m_vKey
  The key.
MemberHolder< Object >  m_ohValue
  The value.
const size32_t  m_nHash
  The key's hash code.
MemberHandle< Entry >  m_hNext
  The next entry in the linked list (an open hashing implementation).

Constructor & Destructor Documentation

Entry ( Object::View  vKey,
    Object::Holder  ohValue,
    size32_t  nHash  
  )     [protected]

Create a new Map::Entry.

Parameters:
  vKey  the assocaited key
  ohValue  the associated value
  hHash  the associated hash code
Returns:
a new Map::Entry

Entry ( Entry::View  vThat  )  [protected]

Instantiate an Entry shallow copying the key and value from the Entry provided.

Parameters:
  vThat  the entry to copy from

Member Data Documentation

MemberHolder<Object> m_ohValue [protected]

The value.

This object reference can change within the life of the Entry.

const size32_t m_nHash [protected]

The key's hash code.

This value will not change for the life of the Entry.

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

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