list.h revision 097af7772652819eddadc27c46ab4a8f830ab96a
/** @file
* IPRT - Generic Doubly Linked List.
*/
/*
* Copyright (C) 2010-2011 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*/
#ifndef ___iprt_list_h
#define ___iprt_list_h
#include <iprt/types.h>
/** @defgroup grp_rt_list RTList - Generic Doubly Linked List
* @ingroup grp_rt
*
* The list implementation is circular without any type wise distintion between
* the list and its nodes. This can be confusing since the list head usually
* resides in a different structure than the nodes, so care must be taken when
* walking the list.
*
* @{
*/
RT_C_DECLS_BEGIN
/**
* A list node of a doubly linked list.
*/
typedef struct RTLISTNODE
{
/** Pointer to the next list node. */
struct RTLISTNODE *pNext;
/** Pointer to the previous list node. */
struct RTLISTNODE *pPrev;
} RTLISTNODE;
/** Pointer to a list node. */
typedef RTLISTNODE *PRTLISTNODE;
/** Pointer to a list node pointer. */
typedef PRTLISTNODE *PPRTLISTNODE;
/** The anchor (head/tail) of a doubly linked list.
*
* @remarks Please use this instead of RTLISTNODE to indicate a list
* head/tail. It makes the code so much easier to read. Also,
* always mention the actual list node type(s) in the comment. */
typedef RTLISTNODE RTLISTANCHOR;
/** Pointer to a doubly linked list anchor. */
typedef RTLISTANCHOR *PRTLISTANCHOR;
/**
* Initialize a list.
*
* @param pList Pointer to an unitialised list.
*/
DECLINLINE(void) RTListInit(PRTLISTNODE pList)
{
pList->pNext = pList;
pList->pPrev = pList;
}
/**
* Append a node to the end of the list.
*
* @param pList The list to append the node to.
* @param pNode The node to append.
*/
DECLINLINE(void) RTListAppend(PRTLISTNODE pList, PRTLISTNODE pNode)
{
pList->pPrev->pNext = pNode;
pNode->pPrev = pList->pPrev;
pNode->pNext = pList;
pList->pPrev = pNode;
}
/**
* Add a node as the first element of the list.
*
* @param pList The list to prepend the node to.
* @param pNode The node to prepend.
*/
DECLINLINE(void) RTListPrepend(PRTLISTNODE pList, PRTLISTNODE pNode)
{
pList->pNext->pPrev = pNode;
pNode->pNext = pList->pNext;
pNode->pPrev = pList;
pList->pNext = pNode;
}
/**
* Inserts a node after the specified one.
*
* @param pCurNode The current node.
* @param pNewNode The node to insert.
*/
DECLINLINE(void) RTListNodeInsertAfter(PRTLISTNODE pCurNode, PRTLISTNODE pNewNode)
{
RTListPrepend(pCurNode, pNewNode);
}
/**
* Inserts a node before the specified one.
*
* @param pCurNode The current node.
* @param pNewNode The node to insert.
*/
DECLINLINE(void) RTListNodeInsertBefore(PRTLISTNODE pCurNode, PRTLISTNODE pNewNode)
{
RTListAppend(pCurNode, pNewNode);
}
/**
* Remove a node from a list.
*
* @param pNode The node to remove.
*/
DECLINLINE(void) RTListNodeRemove(PRTLISTNODE pNode)
{
PRTLISTNODE pPrev = pNode->pPrev;
PRTLISTNODE pNext = pNode->pNext;
pPrev->pNext = pNext;
pNext->pPrev = pPrev;
/* poison */
pNode->pNext = NULL;
pNode->pPrev = NULL;
}
/**
* Checks if a node is the last element in the list.
*
* @retval @c true if the node is the last element in the list.
* @retval @c false otherwise
*
* @param pList The list.
* @param pNode The node to check.
*/
#define RTListNodeIsLast(pList, pNode) ((pNode)->pNext == (pList))
/**
* Checks if a node is the first element in the list.
*
* @retval @c true if the node is the first element in the list.
* @retval @c false otherwise.
*
* @param pList The list.
* @param pNode The node to check.
*/
#define RTListNodeIsFirst(pList, pNode) ((pNode)->pPrev == (pList))
/**
* Checks if a type converted node is actually the dummy element (@a pList).
*
* @retval @c true if the node is the dummy element in the list.
* @retval @c false otherwise.
*
* @param pList The list.
* @param pNodeStruct The node structure to check. Typically
* something obtained from RTListNodeGetNext() or
* RTListNodeGetPrev(). This is NOT a PRTLISTNODE
* but something that contains a RTLISTNODE member!
* @param Type Structure the list node is a member of.
* @param Member The list node member.
*/
#define RTListNodeIsDummy(pList, pNode, Type, Member) \
( (pNode) == RT_FROM_MEMBER((pList), Type, Member) )
/** @copydoc RTListNodeIsDummy */
#define RTListNodeIsDummyCpp(pList, pNode, Type, Member) \
( (pNode) == RT_FROM_CPP_MEMBER((pList), Type, Member) )
/**
* Checks if a list is empty.
*
* @retval @c true if the list is empty.
* @retval @c false otherwise.
*
* @param pList The list to check.
*/
#define RTListIsEmpty(pList) ((pList)->pPrev == (pList))
/**
* Returns the next node in the list.
*
* @returns The next node.
*
* @param pCurNode The current node.
* @param Type Structure the list node is a member of.
* @param Member The list node member.
*/
#define RTListNodeGetNext(pCurNode, Type, Member) \
RT_FROM_MEMBER((pCurNode)->pNext, Type, Member)
/** @copydoc RTListNodeGetNext */
#define RTListNodeGetNextCpp(pCurNode, Type, Member) \
RT_FROM_CPP_MEMBER((pCurNode)->pNext, Type, Member)
/**
* Returns the previous node in the list.
*
* @returns The previous node.
*
* @param pCurNode The current node.
* @param Type Structure the list node is a member of.
* @param Member The list node member.
*/
#define RTListNodeGetPrev(pCurNode, Type, Member) \
RT_FROM_MEMBER((pCurNode)->pPrev, Type, Member)
/** @copydoc RTListNodeGetPrev */
#define RTListNodeGetPrevCpp(pCurNode, Type, Member) \
RT_FROM_CPP_MEMBER((pCurNode)->pPrev, Type, Member)
/**
* Returns the first element in the list (checks for empty list).
*
* @retval Pointer to the first list element.
* @retval NULL if the list is empty.
*
* @param pList List to get the first element from.
* @param Type Structure the list node is a member of.
* @param Member The list node member.
*/
#define RTListGetFirst(pList, Type, Member) \
(!RTListIsEmpty(pList) ? RTListNodeGetNext(pList, Type, Member) : NULL)
/** @copydoc RTListGetFirst */
#define RTListGetFirstCpp(pList, Type, Member) \
(!RTListIsEmpty(pList) ? RTListNodeGetNextCpp(pList, Type, Member) : NULL)
/**
* Returns the last element in the list (checks for empty list).
*
* @retval Pointer to the last list element.
* @retval NULL if the list is empty.
*
* @param pList List to get the last element from.
* @param Type Structure the list node is a member of.
* @param Member The list node member.
*/
#define RTListGetLast(pList, Type, Member) \
(!RTListIsEmpty(pList) ? RTListNodeGetPrev(pList, Type, Member) : NULL)
/** @copydoc RTListGetLast */
#define RTListGetLastCpp(pList, Type, Member) \
(!RTListIsEmpty(pList) ? RTListNodeGetPrevCpp(pList, Type, Member) : NULL)
/**
* Returns the next node in the list or NULL if the end has been reached.
*
* @returns The next node or NULL.
*
* @param pList The list @a pCurNode is linked on.
* @param pCurNode The current node, of type @a Type.
* @param Type Structure the list node is a member of.
* @param Member The list node member.
*/
#define RTListGetNext(pList, pCurNode, Type, Member) \
( (pCurNode)->Member.pNext != (pList) ? RT_FROM_MEMBER((pCurNode)->Member.pNext, Type, Member) : NULL )
/** @copydoc RTListGetNext */
#define RTListGetNextCpp(pList, pCurNode, Type, Member) \
( (pCurNode)->Member.pNext != (pList) ? RT_FROM_CPP_MEMBER((pCurNode)->Member.pNext, Type, Member) : NULL )
/**
* Returns the previous node in the list or NULL if the start has been reached.
*
* @returns The previous node or NULL.
*
* @param pList The list @a pCurNode is linked on.
* @param pCurNode The current node, of type @a Type.
* @param Type Structure the list node is a member of.
* @param Member The list node member.
*/
#define RTListGetPrev(pList, pCurNode, Type, Member) \
( (pCurNode)->Member.pPrev != (pList) ? RT_FROM_MEMBER((pCurNode)->Member.pPrev, Type, Member) : NULL )
/** @copydoc RTListGetPrev */
#define RTListGetPrevCpp(pList, pCurNode, Type, Member) \
( (pCurNode)->Member.pPrev != (pList) ? RT_FROM_CPP_MEMBER((pCurNode)->Member.pPrev, Type, Member) : NULL )
/**
* Enumerate the list in head to tail order.
*
* @param pList List to enumerate.
* @param pIterator The iterator variable name.
* @param Type Structure the list node is a member of.
* @param Member The list node member name.
*/
#define RTListForEach(pList, pIterator, Type, Member) \
for (pIterator = RTListNodeGetNext(pList, Type, Member); \
!RTListNodeIsDummy(pList, pIterator, Type, Member); \
pIterator = RT_FROM_MEMBER((pIterator)->Member.pNext, Type, Member) )
/** @copydoc RTListForEach */
#define RTListForEachCpp(pList, pIterator, Type, Member) \
for (pIterator = RTListNodeGetNextCpp(pList, Type, Member); \
!RTListNodeIsDummyCpp(pList, pIterator, Type, Member); \
pIterator = RT_FROM_CPP_MEMBER((pIterator)->Member.pNext, Type, Member) )
/**
* Enumerate the list in head to tail order, safe against removal of the
* current node.
*
* @param pList List to enumerate.
* @param pIterator The iterator variable name.
* @param pIterNext The name of the variable saving the pointer to
* the next element.
* @param Type Structure the list node is a member of.
* @param Member The list node member name.
*/
#define RTListForEachSafe(pList, pIterator, pIterNext, Type, Member) \
for (pIterator = RTListNodeGetNext(pList, Type, Member), \
pIterNext = RT_FROM_MEMBER((pIterator)->Member.pNext, Type, Member); \
!RTListNodeIsDummy(pList, pIterator, Type, Member); \
pIterator = pIterNext, \
pIterNext = RT_FROM_MEMBER((pIterator)->Member.pNext, Type, Member) )
/** @copydoc RTListForEachSafe */
#define RTListForEachSafeCpp(pList, pIterator, pIterNext, Type, Member) \
for (pIterator = RTListNodeGetNextCpp(pList, Type, Member), \
pIterNext = RT_FROM_CPP_MEMBER((pIterator)->Member.pNext, Type, Member); \
!RTListNodeIsDummyCpp(pList, pIterator, Type, Member); \
pIterator = pIterNext, \
pIterNext = RT_FROM_CPP_MEMBER((pIterator)->Member.pNext, Type, Member) )
/**
* Enumerate the list in reverse order (tail to head).
*
* @param pList List to enumerate.
* @param pIterator The iterator variable name.
* @param Type Structure the list node is a member of.
* @param Member The list node member name.
*/
#define RTListForEachReverse(pList, pIterator, Type, Member) \
for (pIterator = RTListNodeGetPrev(pList, Type, Member); \
!RTListNodeIsDummy(pList, pIterator, Type, Member); \
pIterator = RT_FROM_MEMBER((pIterator)->Member.pPrev, Type, Member) )
/** @copydoc RTListForEachReverse */
#define RTListForEachReverseCpp(pList, pIterator, Type, Member) \
for (pIterator = RTListNodeGetPrevCpp(pList, Type, Member); \
!RTListNodeIsDummyCpp(pList, pIterator, Type, Member); \
pIterator = RT_FROM_CPP_MEMBER((pIterator)->Member.pPrev, Type, Member) )
/**
* Enumerate the list in reverse order (tail to head).
*
* @param pList List to enumerate.
* @param pIterator The iterator variable name.
* @param pIterPrev The name of the variable saving the pointer to
* the previous element.
* @param Type Structure the list node is a member of.
* @param Member The list node member name.
*/
#define RTListForEachReverseSafe(pList, pIterator, pIterPrev, Type, Member) \
for (pIterator = RTListNodeGetPrev(pList, Type, Member), \
pIterPrev = RT_FROM_MEMBER((pIterator)->Member.pPrev, Type, Member); \
!RTListNodeIsDummy(pList, pIterator, Type, Member); \
pIterator = pIterPrev, \
pIterPrev = RT_FROM_MEMBER((pIterator)->Member.pPrev, Type, Member) )
/** @copydoc RTListForEachReverseSafe */
#define RTListForEachReverseSafeCpp(pList, pIterator, pIterPrev, Type, Member) \
for (pIterator = RTListNodeGetPrevCpp(pList, Type, Member), \
pIterPrev = RT_FROM_CPP_MEMBER((pIterator)->Member.pPrev, Type, Member); \
!RTListNodeIsDummyCpp(pList, pIterator, Type, Member); \
pIterator = pIterPrev, \
pIterPrev = RT_FROM_CPP_MEMBER((pIterator)->Member.pPrev, Type, Member) )
/**
* Move the given list to a new list header.
*
* @param pListDst The new list.
* @param pListSrc The list to move.
*/
DECLINLINE(void) RTListMove(PRTLISTNODE pListDst, PRTLISTNODE pListSrc)
{
if (!RTListIsEmpty(pListSrc))
{
pListDst->pNext = pListSrc->pNext;
pListDst->pPrev = pListSrc->pPrev;
/* Adjust the first and last element links */
pListDst->pNext->pPrev = pListDst;
pListDst->pPrev->pNext = pListDst;
/* Finally remove the elements from the source list */
RTListInit(pListSrc);
}
}
/**
* List concatenation.
*
* @returns nothing.
* @param pListDst The destination list.
* @param pListSrc The source list to concatenate.
*/
DECLINLINE(void) RTListConcatenate(PRTLISTANCHOR pListDst, PRTLISTANCHOR pListSrc)
{
if (!RTListIsEmpty(pListSrc))
{
PRTLISTNODE pFirst = pListSrc->pNext;
PRTLISTNODE pLast = pListSrc->pPrev;
pListDst->pPrev->pNext = pFirst;
pFirst->pPrev = pListDst->pPrev;
pLast->pNext = pListDst;
pListDst->pPrev = pLast;
/* Finally remove the elements from the source list */
RTListInit(pListSrc);
}
}
RT_C_DECLS_END
/** @} */
#endif