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XrdOucDLlist.hh
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#ifndef __OUC_DLIST__
#define __OUC_DLIST__
/******************************************************************************/
/* */
/* X r d O u c D L l i s t . h h */
/* */
/*(c) 2003 by the Board of Trustees of the Leland Stanford, Jr., University */
/* All Rights Reserved */
/*Produced by Andrew Hanushevsky for Stanford University under contract */
/* DE-AC02-76-SFO0515 with the Deprtment of Energy */
/* */
/* This file is part of the XRootD software suite. */
/* */
/* XRootD is free software: you can redistribute it and/or modify it under */
/* the terms of the GNU Lesser General Public License as published by the */
/* Free Software Foundation, either version 3 of the License, or (at your */
/* option) any later version. */
/* */
/* XRootD is distributed in the hope that it will be useful, but WITHOUT */
/* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or */
/* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public */
/* License for more details. */
/* */
/* You should have received a copy of the GNU Lesser General Public License */
/* along with XRootD in a file called COPYING.LESSER (LGPL license) and file */
/* COPYING (GPL license). If not, see <http://www.gnu.org/licenses/>. */
/* */
/* The copyright holder's institutional names and contributor's names may not */
/* be used to endorse or promote products derived from this software without */
/* specific prior written permission of the institution or contributor. */
/******************************************************************************/
template<class T>
class XrdOucDLlist
{
public:
XrdOucDLlist(T *itemval=0) {prev=this; next=this; item=itemval;}
~XrdOucDLlist() {if (prev != next) Remove();}
// Apply() applies the specified function to every item in the list. Apply()
// is pointer-safe in that the current node pointers may be changed
// without affecting the traversal of the list. An argument may be
// passed to the function. A null pointer is returned if the list
// was completely traversed. Otherwise, the pointer to the node on
// which the applied function returned a non-zero value is returned.
// An optional starting point may be passed.
//
T *Apply(int (*func)(T *, void *), void *Arg, XrdOucDLlist *Start=0)
{XrdOucDLlist *nextnode, *node;
if (Start) node = Start; // Set correct starting point
else node = this;
// Iterate through the list until we hit ourselves again. We do the
// loop once on the current node to allow for anchorless lists.
//
do {nextnode = node->next;
if (node->item && (*func)(node->item, Arg)) return node->item;
node = nextnode;
} while (node != this);
// All done, indicate we went through the whole list
//
return (T *)0;
}
// Insert() inserts the specified node immediately off itself. If an item value
// is not given, it is not changed.
//
void Insert(XrdOucDLlist *Node, T *Item=0)
{Node->next = next; // Chain in the item;
next->prev = Node;
next = Node;
Node->prev = this;
if (Item) Node->item = Item;
}
// Item() supplies the item value associated with itself (used with Next()).
//
T *Item() {return item;}
// Remove() removes itself from whatever list it happens to be in.
//
void Remove()
{prev->next = next; // Unchain the item
next->prev = prev;
next = this;
prev = this;
}
// Next() supplies the next list node.
//
XrdOucDLlist *Next() {return next;}
// Prev() supplies the prev list node.
//
XrdOucDLlist *Prev() {return prev;}
// Set the item pointer
//
void setItem(T *ival) {item = ival;}
// Singleton() indicates whether or not the node points to something
//
int Singleton() {return next == this;}
private:
XrdOucDLlist *next;
XrdOucDLlist *prev;
T *item;
};
#endif
XrdOucDLlist
Definition XrdOucDLlist.hh:36
XrdOucDLlist::Singleton
int Singleton()
Definition XrdOucDLlist.hh:106
XrdOucDLlist::XrdOucDLlist
XrdOucDLlist(T *itemval=0)
Definition XrdOucDLlist.hh:39
XrdOucDLlist::setItem
void setItem(T *ival)
Definition XrdOucDLlist.hh:102
XrdOucDLlist::~XrdOucDLlist
~XrdOucDLlist()
Definition XrdOucDLlist.hh:40
XrdOucDLlist::Apply
T * Apply(int(*func)(T *, void *), void *Arg, XrdOucDLlist *Start=0)
Definition XrdOucDLlist.hh:50
XrdOucDLlist::Insert
void Insert(XrdOucDLlist *Node, T *Item=0)
Definition XrdOucDLlist.hh:71
XrdOucDLlist::Next
XrdOucDLlist * Next()
Definition XrdOucDLlist.hh:94
XrdOucDLlist::Remove
void Remove()
Definition XrdOucDLlist.hh:85
XrdOucDLlist::Item
T * Item()
Definition XrdOucDLlist.hh:81
XrdOucDLlist::Prev
XrdOucDLlist * Prev()
Definition XrdOucDLlist.hh:98