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622 lines
14 KiB
C
622 lines
14 KiB
C
/*
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* dlist.c
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*
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* Copyright (C) 2003 Eric J Bohm
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 021110307 USA
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*
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*/
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/* Double linked list implementation.
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* You allocate the data and give dlist the pointer.
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* If your data is complex set the dlist->del_func to a an appropriate
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* delete function. Otherwise dlist will just use free.
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*/
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#include "stdlib.h"
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#include "dlist.h"
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/*
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* Return pointer to node at marker.
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* else null if no nodes.
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*/
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inline void *dlist_mark(Dlist *list)
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{
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if(list->marker!=NULL)
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return(list->marker->data);
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else
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return(NULL);
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}
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/*
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* Set marker to start.
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*/
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inline void dlist_start(Dlist *list)
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{
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list->marker=list->head;
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}
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/*
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* Set marker to end.
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*/
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inline void dlist_end(Dlist *list)
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{
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list->marker=list->head;
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}
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/* internal use function
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* quickie inline to consolidate the marker movement logic
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* in one place
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*
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* when direction true it moves marker after
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* when direction false it moves marker before.
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* return pointer to data at new marker
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* if nowhere to move the marker in desired direction return null
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*/
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inline void *_dlist_mark_move(Dlist *list,int direction)
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{
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if(direction)
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{
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if( list->marker && list->marker->next!=NULL)
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list->marker=list->marker->next;
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else
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return(NULL);
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}
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else
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{
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if( list->marker && list->marker->prev!=NULL)
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list->marker=list->marker->prev;
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else
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return(NULL);
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}
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if(list->marker!=list->head)
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return(list->marker->data);
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else
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return(NULL);
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}
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/*
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* Create new linked list to store nodes of datasize.
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* return null if list cannot be created.
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*/
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Dlist *dlist_new(size_t datasize)
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{
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Dlist *list=NULL;
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if((list=malloc(sizeof(Dlist))))
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{
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list->marker=NULL;
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list->count=0L;
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list->data_size=datasize;
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list->del_func=free;
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list->head=&(list->headnode);
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list->head->prev=NULL;
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list->head->next=NULL;
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list->head->data=NULL;
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}
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return(list);
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}
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/*
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* Create new linked list to store nodes of datasize set list
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* data node delete function to the passed in del_func
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* return null if list cannot be created.
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*/
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Dlist *dlist_new_with_delete(size_t datasize,void (*del_func)(void*))
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{
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Dlist *list=NULL;
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list=dlist_new(datasize);
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if(list!=NULL)
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list->del_func=del_func;
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return(list);
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}
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/*
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* remove marker node from list
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* call data_delete function on data if registered.
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* otherwise call free.
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* when direction true it moves marker after
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* when direction false it moves marker before.
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* free marker node
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* return nothing.
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*/
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void dlist_delete(Dlist *list,int direction)
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{
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if((list->marker != list->head)&&(list->marker!=NULL))
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{
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DL_node *corpse;
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corpse=list->marker;
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_dlist_mark_move(list,direction);
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if(list->head->next==corpse)
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list->head->next=corpse->next;
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if(list->head->prev==corpse)
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list->head->prev=corpse->prev;
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if(corpse->prev!=NULL) //should be impossible
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corpse->prev->next=corpse->next;
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if(corpse->next!=NULL) //should be impossible
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corpse->next->prev=corpse->prev;
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list->del_func(corpse->data);
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list->count--;
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free(corpse);
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}
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}
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/*
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* Insert node containing data at marker.
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* If direction true it inserts after.
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* If direction false it inserts before.
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* move marker to inserted node
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* return pointer to inserted node
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*/
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void *dlist_insert(Dlist *list,void *data,int direction)
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{
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DL_node *new_node=NULL;
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if(list==NULL || data==NULL)
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return(NULL);
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if(list->marker==NULL) //in case the marker ends up unset
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list->marker=list->head;
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if((new_node=malloc(sizeof(DL_node))))
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{
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new_node->data=data;
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new_node->prev=NULL;
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new_node->next=NULL;
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list->count++;
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if(list->head->next==NULL) //no l
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{
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list->head->next=list->head->prev=new_node;
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new_node->prev=list->head;
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new_node->next=list->head;
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}
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else if(direction)
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{
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new_node->next=list->marker->next;
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new_node->prev=list->marker;
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list->marker->next->prev=new_node;
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list->marker->next=new_node;
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}
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else
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{
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new_node->prev=list->marker->prev;
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new_node->next=list->marker;
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list->marker->prev->next=new_node;
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list->marker->prev=new_node;
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}
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list->marker=new_node;
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}
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else
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{
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return(NULL);
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}
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return(list->marker->data);
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}
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/* internal use only
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* Insert dl_node at marker.
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* If direction true it inserts after.
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* If direction false it inserts before.
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* move marker to inserted node
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* return pointer to inserted node
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*/
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void *_dlist_insert_dlnode(struct dlist *list,struct dl_node *new_node,int direction)
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{
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if(list==NULL || new_node==NULL)
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return(NULL);
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if(list->marker==NULL) //in case the marker ends up unset
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list->marker=list->head;
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list->count++;
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if(list->head->next==NULL)
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{
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list->head->next=list->head->prev=new_node;
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new_node->prev=list->head;
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new_node->next=list->head;
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}
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else if(direction)
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{
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new_node->next=list->marker->next;
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new_node->prev=list->marker;
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list->marker->next->prev=new_node;
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list->marker->next=new_node;
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}
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else
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{
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new_node->prev=list->marker->prev;
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new_node->next=list->marker;
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list->marker->prev->next=new_node;
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list->marker->prev=new_node;
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}
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list->marker=new_node;
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return(list->marker);
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}
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/*
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* Remove DL_node from list without deallocating data.
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* if marker == killme .
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* when direction true it moves marker after
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* when direction false it moves marker before.
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* to previous if there is no next.
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*/
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void *_dlist_remove(Dlist *list,DL_node *killme,int direction)
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{
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if(killme!=NULL)
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{
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void *killer_data=killme->data;
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// take care of head and marker pointers.
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if(list->marker==killme)
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_dlist_mark_move(list,direction);
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if(killme ==list->head->next)
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list->head->next=killme->next;
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if(killme==list->head->prev)
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list->head->prev=killme->prev;
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// remove from list
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if(killme->prev !=NULL)
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killme->prev->next=killme->next;
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if(killme->next !=NULL)
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killme->next->prev=killme->prev;
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list->count--;
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free(killme);
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return(killer_data);
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}
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else
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return (NULL);
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}
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/*
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* move dl_node from source to dest
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* if marker == target .
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* when direction true it moves marker after
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* when direction false it moves marker before.
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* to previous if there is no next.
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*/
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void dlist_move(struct dlist *source, struct dlist *dest, struct dl_node *target,int direction)
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{
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if(target!=NULL)
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{
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if(target==source->head)
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{
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//not even going to try
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}
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else
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{
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// take care of head and marker pointers.
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if(source->marker==target)
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_dlist_mark_move(source,direction);
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if(target ==source->head->next)
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source->head->next=target->next;
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if(target==source->head->prev)
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source->head->prev=target->prev;
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// remove from list
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if(source->count==1)
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{
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target->prev=NULL;
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target->next=NULL;
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source->head->next=NULL;
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source->head->prev=NULL;
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}
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else
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{
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if(target->prev !=NULL)
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target->prev->next=target->next;
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if(target->next !=NULL)
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target->next->prev=target->prev;
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target->prev=NULL;
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target->next=NULL;
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}
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source->count--;
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_dlist_insert_dlnode(dest,target,direction);
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}
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}
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}
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/*
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* Insert node containing data after end.
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*/
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void dlist_push(Dlist *list,void *data)
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{
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list->marker=list->head->prev;
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dlist_insert(list,data,1);
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}
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/*
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* Insert node containing data at start.
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*/
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void dlist_unshift(Dlist *list,void *data)
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{
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list->marker=list->head->next;
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dlist_insert(list,data,0);
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}
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void dlist_unshift_sorted(Dlist *list, void *data,
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int (*sorter)(void *new_elem, void *old_elem))
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{
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if (list->count == 0)
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dlist_unshift(list, data);
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else {
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list->marker=list->head->next;
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dlist_insert_sorted(list, data, sorter);
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}
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}
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/*
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* Remove end node from list.
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* Return pointer to data in removed node.
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* Null if no nodes.
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*/
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void *dlist_pop(Dlist *list)
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{
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return(_dlist_remove(list,list->head->prev,0));
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}
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/*
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* Remove start node from list.
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* Return pointer to data in removed node.
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* Null if no nodes.
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*/
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void *dlist_shift(Dlist *list)
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{
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return(_dlist_remove(list,list->head->next,1));
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}
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/*
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* destroy the list freeing all memory
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*/
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void dlist_destroy(Dlist *list)
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{
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if(list !=NULL)
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{
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dlist_start(list);
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dlist_next(list);
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while (dlist_mark(list)) {
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dlist_delete(list,1);
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}
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free(list);
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}
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}
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/**
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* Return void pointer to list_data element matching comp function criteria
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* else null
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* Does not move the marker.
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*/
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void *dlist_find_custom(struct dlist *list, void *target, int (*comp)(void *, void *))
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{
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/* test the comp function on each node */
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struct dl_node *nodepointer;
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dlist_for_each_nomark(list,nodepointer)
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if(comp(target,nodepointer->data))
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return(nodepointer->data);
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return(NULL);
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}
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/**
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* Apply the node_operation function to each data node in the list
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*/
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void dlist_transform(struct dlist *list, void (*node_operation)(void *))
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{
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struct dl_node *nodepointer;
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dlist_for_each_nomark(list,nodepointer)
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node_operation(nodepointer->data);
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}
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/**
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* insert new into list in sorted order
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* sorter function in form int sorter(new,ith)
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* must return 1 for when new should go before ith
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* else 0
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* return pointer to inserted node
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* NOTE: assumes list is already sorted
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*/
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void *dlist_insert_sorted(struct dlist *list, void *new, int (*sorter)(void *, void *))
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{
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for(dlist_start(list),dlist_next(list); \
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list->marker!=list->head && !sorter(new,list->marker->data);dlist_next(list));
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return(dlist_insert_before(list,new));
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}
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/*
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* NOTE: internal use only
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*/
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int _dlist_merge(struct dlist *listsource, struct dlist *listdest, unsigned int passcount, int (*compare)(void *, void *))
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{
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struct dl_node *l1head;
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struct dl_node *l2head;
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struct dl_node *target;
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unsigned int l1count=0;
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unsigned int l2count=0;
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unsigned int mergecount=0;
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while(listsource->count>0)
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{
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l1head=listsource->head->next;
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l2head=l1head;
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while((l1count<passcount)&&(l2head!=listsource->head))
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{
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l2head=l2head->next;
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l1count++;
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}
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// so now we have two lists to merge
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if(l2head==listsource->head)
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{// l2count
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l2count=0;
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}
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else
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{
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l2count=passcount;
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}
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while(l1count>0 || l2count>0)
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{
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mergecount++;
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if((l2count>0)&&(l1count>0))
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{
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// we have things to merge
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int result=compare(l1head->data,l2head->data);
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if(result>0)
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{
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// move from l2
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target=l2head;
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l2head=l2head->next;
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dlist_move(listsource,listdest,target,1);
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l2count--;
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if(l2head==listsource->head)
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l2count=0;
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}
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else
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{
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// move from l1
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target=l1head;
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l1head=l1head->next;
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dlist_move(listsource,listdest,target,1);
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l1count--;
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}
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}
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else if(l1count>0)
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{
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// only have l1 to work with
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while(l1count>0)
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{
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target=l1head;
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l1head=l1head->next;
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dlist_move(listsource,listdest,target,1);
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l1count--;
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}
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}
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else if(l2count>0)
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{
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// only have l2 to work with
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while(l2count>0)
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{
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if(l2head==listsource->head)
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{
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l2count=0;
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}
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else
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{
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target=l2head;
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l2head=l2head->next;
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dlist_move(listsource,listdest,target,1);
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l2count--;
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}
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}
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}
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else
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{ //nothing left and this should be unreachable
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}
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}
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}
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return(mergecount);
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}
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/**
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* mergesort the list based on compare
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* compare function in form int sorter(void * a,void * b)
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* must return >0 for a after b
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* must return <0 for a before b
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* else 0
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* NOTE: mergesort changes the mark pointer
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*/
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void dlist_sort_custom(struct dlist *list, int (*compare)(void *, void *))
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{
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struct dlist *listsource, *listdest, *swap;
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struct dlist *templist;
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unsigned int passcount = 1;
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unsigned int mergecount = 1;
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dlist_start(list);
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templist = dlist_new(list->data_size);
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// do nothing if there isn't anything to sort
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listsource = list;
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listdest = templist;
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if(listsource->count<2)
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{ //nothing to do
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return;
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}
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else
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{
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while(mergecount>0)
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{
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mergecount=_dlist_merge(listsource, listdest, passcount, compare);
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if(mergecount>1)
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{
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passcount=passcount*2;
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//start new pass
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swap=listsource;
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listsource=listdest;
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listdest=swap;
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}
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}
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}
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// now put the input list pointers right
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// list pointers = newlist pointers
|
|
// including the forward and next nodes prev and back pointers
|
|
if(list->count==0)
|
|
{//copy
|
|
list->marker = listdest->marker;
|
|
list->count = listdest->count;
|
|
list->data_size = listdest->data_size;
|
|
list->del_func = listdest->del_func;
|
|
list->head->prev = listdest->head->prev;
|
|
list->head->next = listdest->head->next;
|
|
list->head->data = listdest->head->data;
|
|
list->head->next->prev=list->head;
|
|
list->head->prev->next=list->head;
|
|
templist->head->next=NULL;
|
|
templist->head->prev=NULL;
|
|
templist->count=0;
|
|
}
|
|
else
|
|
{// no need to copy
|
|
|
|
}
|
|
|
|
dlist_destroy(templist);
|
|
}
|
|
|
|
|
|
|
|
/* internal use function
|
|
swaps elements a and b
|
|
No sense in juggling node pointers when we can just swap the data pointers
|
|
*/
|
|
|
|
void _dlist_swap(struct dlist *list, struct dl_node *a, struct dl_node *b)
|
|
{
|
|
|
|
void *swap=a->data;
|
|
a->data=b->data;
|
|
b->data=swap;
|
|
|
|
}
|
|
|