UtlChain Class Reference

#include <UtlLink.h>

Inheritance diagram for UtlChain:

Collaboration diagram for UtlChain:

Public Member Functions
	UtlChain ()
	Constructor initializes to unlinked. More...
	~UtlChain ()
	Destructor. More...

Protected Member Functions
Chain Operations
These methods manipulate the forward and backward links within a chain. They do no do anything with respect to any header, so they can be used to implement chains that are linear (NULL terminated) or circular.
bool	isUnLinked () const
	Is this block not linked to anything? More...
void	unchain ()
	Take the link out of its chain. More...
void	chainBefore (UtlChain *existing)
	Insert a new UtlChain before existing. More...
void	chainAfter (UtlChain *existing)
	Insert a new UtlChain after existing.. More...
List Operations
These methods do the special handling for using a UtlChain as a list header. The UtlChain.next points to the head (first) UtlLink on the list. The UtlChain.prev points to the tail (last) UtlLink. The UtlLink objects on the list form a NULL-terminated chain - they do not point to the UtlChain that serves as the header.
UtlChain *	listHead () const
	Returns the head (first) UtlLink on the list (or NULL if the list is empty). More...
UtlChain *	listTail () const
	Returns the tail (last) UtlLink on the list (or NULL if the list is empty). More...
UtlLink *	head () const
	Returns the head (first) UtlLink on the list (or NULL if the list is empty). More...
UtlLink *	tail () const
	Returns the tail (last) UtlLink on the list (or NULL if the list is empty). More...
void	listBefore (UtlChain *list, UtlChain *existing)
	Insert this link into a list before an existing entry (before NULL == at the tail). More...
void	listAfter (UtlChain *list, UtlChain *existing)
	Insert this link into a list after an existing entry (after NULL == at the head). More...
UtlChain *	detachFromList (UtlChain *listHead)
	Remove a link from a list. More...

Protected Attributes
UtlChain *	prev
	backward chain pointer More...
UtlChain *	next
	forward chain pointer More...

Friends
class	UtlChainPool
class	UtlLink
class	UtlPair
class	UtlContainer
class	UtlList
class	UtlHashMap
class	UtlHashMapIterator
class	UtlHashBag
class	UtlHashBagIterator
class	UtlChainTest
class	UtlLinkTest

Detailed Description

UtlChain is the internal class that implements the linked list blocks for other Utl classes. It may not be used directly because by itself it is not thread safe. Use one of the lists types derived from UtlList.

Each UltLinkChain links forward (next) and backward (prev) in the chain of links; ends of a chain are indicated by NULL values. A UtlChain not in a chain, including a newly constructed instance, have NULL pointers in both directions.

A UtlChain can also be used as a list header whose links point to the ends of a NULL terminated list.

Constructor & Destructor Documentation

UtlChain ( )

inline

Constructor initializes to unlinked.

~UtlChain ( )

inline

Destructor.

Member Function Documentation

bool isUnLinked ( ) const

inlineprotected

Is this block not linked to anything?

void unchain ( )

inlineprotected

Take the link out of its chain.

void chainBefore ( UtlChain *  existing )

inlineprotected

Insert a new UtlChain before existing.

This may be called only on an unlinked UtlChain

void chainAfter ( UtlChain *  existing )

inlineprotected

Insert a new UtlChain after existing..

This may be called only on an unlinked UtlChain

UtlChain* listHead ( ) const

inlineprotected

Returns the head (first) UtlLink on the list (or NULL if the list is empty).

UtlChain* listTail ( ) const

inlineprotected

Returns the tail (last) UtlLink on the list (or NULL if the list is empty).

UtlLink* head ( ) const

inlineprotected

Returns the head (first) UtlLink on the list (or NULL if the list is empty).

UtlLink* tail ( ) const

inlineprotected

Returns the tail (last) UtlLink on the list (or NULL if the list is empty).

void listBefore ( UtlChain *  list, UtlChain *  existing  )

protected

Insert this link into a list before an existing entry (before NULL == at the tail).

Insert a new item into a list before an existing entry (before NULL == at the tail).

Note

This method does not verify that the existing element is actually on the list; doing so is the responsibility of the caller. If the list is empty, existing must be NULL.

Parameters

list	the list to insert into
existing	the UtlLink for the position in the list to insert before. NULL means at the end of the list.

void listAfter ( UtlChain *  list, UtlChain *  existing  )

protected

Insert this link into a list after an existing entry (after NULL == at the head).

Insert a new item into a list before an existing entry (after NULL == at the head).

Note

This method does not verify that the existing element is actually on the list; doing so is the responsibility of the caller. If the list is empty, existing must be NULL.

Parameters

list	the list to insert into
existing	the UtlLink for the position in the list to insert after. NULL means at the beginning of the list.

UtlChain * detachFromList ( UtlChain *  listHead )

protected

Remove a link from a list.

Note

This method does not verify that the UtlLink object being detached is actually on the specified list; doing so is the responsibility of the caller.

Friends And Related Function Documentation

friend class UtlChainPool

friend

friend class UtlLink

friend

friend class UtlPair

friend

friend class UtlContainer

friend

friend class UtlList

friend

friend class UtlHashMap

friend

friend class UtlHashMapIterator

friend

friend class UtlHashBag

friend

friend class UtlHashBagIterator

friend

friend class UtlChainTest

friend

friend class UtlLinkTest

friend

Member Data Documentation

UtlChain* prev

protected

backward chain pointer

UtlChain* next

protected

forward chain pointer