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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
/*[]---------------------------------------------------[]*/
/*| |*/
/*| list.c - bidirectional list class |*/
/*| |*/
/*| |*/
/*| Author: Alexander Gelfenbain |*/
/*[]---------------------------------------------------[]*/
#include <assert.h>
#include <cstdlib>
#include "list.h"
namespace {
/*- private data types */
struct lnode {
struct lnode *next;
struct lnode *prev;
void *value;
};
}
struct list_ {
lnode *head, *tail, *cptr;
size_t aCount;
list_destructor eDtor;
};
/*- private methods */
static lnode *newNode(void *el)
{
lnode *ptr = static_cast<lnode *>(std::malloc(sizeof(lnode)));
assert(ptr != nullptr);
ptr->value = el;
return ptr;
}
static lnode *appendPrim(list pThis, void *el)
{
lnode *ptr = newNode(el);
lnode **flink, *blink;
if (pThis->tail != nullptr) {
flink = &(pThis->tail->next);
blink = pThis->tail;
} else {
flink = &pThis->head;
blink = nullptr;
pThis->cptr = ptr; /*- list was empty - set current to this element */
}
*flink = ptr;
pThis->tail = ptr;
ptr->prev = blink;
ptr->next = nullptr;
pThis->aCount++;
return ptr;
}
/*- public methods */
list listNewEmpty() /*- default ctor */
{
list pThis = static_cast<list>(std::malloc(sizeof(struct list_)));
assert(pThis != nullptr);
pThis->aCount = 0;
pThis->eDtor = nullptr;
pThis->head = pThis->tail = pThis->cptr = nullptr;
return pThis;
}
void listDispose(list pThis) /*- dtor */
{
assert(pThis != nullptr);
listClear(pThis);
std::free(pThis);
}
void listSetElementDtor(list pThis, list_destructor f)
{
assert(pThis != nullptr);
pThis->eDtor = f;
}
/* calling this function on an empty list is a run-time error */
void *listCurrent(list pThis)
{
assert(pThis != nullptr);
assert(pThis->cptr != nullptr);
return pThis->cptr->value;
}
int listCount(list pThis)
{
assert(pThis != nullptr);
return pThis->aCount;
}
int listIsEmpty(list pThis)
{
assert(pThis != nullptr);
return pThis->aCount == 0;
}
int listNext(list pThis)
{
return listSkipForward(pThis, 1);
}
int listSkipForward(list pThis, int n)
{
int m = 0;
assert(pThis != nullptr);
if (pThis->cptr == nullptr) return 0;
while (n != 0) {
if (pThis->cptr->next == nullptr) break;
pThis->cptr = pThis->cptr->next;
n--;
m++;
}
return m;
}
int listToFirst(list pThis)
{
assert(pThis != nullptr);
if (pThis->cptr != pThis->head) {
pThis->cptr = pThis->head;
return 1;
}
return 0;
}
int listToLast(list pThis)
{
assert(pThis != nullptr);
if (pThis->cptr != pThis->tail) {
pThis->cptr = pThis->tail;
return 1;
}
return 0;
}
list listAppend(list pThis, void *el)
{
assert(pThis != nullptr);
appendPrim(pThis, el);
return pThis;
}
list listRemove(list pThis)
{
lnode *ptr = nullptr;
if (pThis->cptr == nullptr) return pThis;
if (pThis->cptr->next != nullptr) {
ptr = pThis->cptr->next;
pThis->cptr->next->prev = pThis->cptr->prev;
} else {
pThis->tail = pThis->cptr->prev;
}
if (pThis->cptr->prev != nullptr) {
if (ptr == nullptr) ptr = pThis->cptr->prev;
pThis->cptr->prev->next = pThis->cptr->next;
} else {
pThis->head = pThis->cptr->next;
}
if (pThis->eDtor) pThis->eDtor(pThis->cptr->value); /* call the dtor callback */
std::free(pThis->cptr);
pThis->aCount--;
pThis->cptr = ptr;
return pThis;
}
list listClear(list pThis)
{
lnode *node = pThis->head, *ptr;
while (node) {
ptr = node->next;
if (pThis->eDtor) pThis->eDtor(node->value); /* call the dtor callback */
std::free(node);
pThis->aCount--;
node = ptr;
}
pThis->head = pThis->tail = pThis->cptr = nullptr;
assert(pThis->aCount == 0);
return pThis;
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|
