LinkedLists.cpp

/* CommonLibs/LinkedLists.cpp */
/*-
 * Copyright 2008 Free Software Foundation, Inc.
 * Copyright 2014 Range Networks, Inc.
 *
 * This software is distributed under the terms of the GNU Affero Public License.
 * See the COPYING file in the main directory for details.
 *
 * This use of this software may be subject to additional restrictions.
 * See the LEGAL file in the main directory for details.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "LinkedLists.h"

void PointerFIFO::push_front(void *val) // by pat
{
	// Pat added this routine for completeness, but never used or tested.
	// The first person to use this routine should remove this assert.
	ListNode *node = allocate();
	node->data(val);
	node->next(mHead);
	mHead = node;
	if (!mTail)
		mTail = node;
	mSize++;
}

void PointerFIFO::put(void *val)
{
	ListNode *node = allocate();
	node->data(val);
	node->next(NULL);
	if (mTail != NULL)
		mTail->next(node);
	mTail = node;
	if (mHead == NULL)
		mHead = node;
	mSize++;
}

/** Take an item from the FIFO. */
void *PointerFIFO::get()
{
	// empty list?
	if (mHead == NULL)
		return NULL;
	// normal case
	ListNode *next = mHead->next();
	void *retVal = mHead->data();
	release(mHead);
	mHead = next;
	if (next == NULL)
		mTail = NULL;
	mSize--;
	return retVal;
}

ListNode *PointerFIFO::allocate()
{
	if (mFreeList == NULL)
		return new ListNode;
	ListNode *retVal = mFreeList;
	mFreeList = mFreeList->next();
	return retVal;
}

void PointerFIFO::release(ListNode *wNode)
{
	wNode->next(mFreeList);
	mFreeList = wNode;
}