#include "bomber.h"
#include "list.h"
#include "utils.h"

static listitem *things=0, *free_things;

void allocthings(void) {
	int i;
	const int num = MAXTHINGS;

	if (!things) {
		things = calloc(sizeof(listitem), num);
	} else {
		memset(things, 0, sizeof(listitem)*num);
	}
	if(!things) nomem("Trying to allocate thing memory");
	for(i=0;i<num-1;++i) {
		things[i].next = &things[i+1];
	}
	things[i].next = 0;
	free_things = things;
}

void *allocentry(void) {
	listitem *entry = free_things;

	if (free_things) {
		free_things = free_things->next;
		memset(entry, 0, sizeof(*entry));
	}
	return entry;
}

void freeentry(void *_entry) {
	listitem *entry = _entry;

	entry->next = free_things;
	free_things = entry;
}

void addtail(void *_header,void *_entry) {
	listitem *header = _header, *entry = _entry;

	while (header->next) header = header->next;
	header->next = entry;
	entry->next = 0;
}

void delink(void *_header,void *_entry) {
	listitem *header = _header, *entry = _entry;

	while (header->next != entry) header = header->next;
	header->next = entry->next;
	entry->next = 0;
	freeentry(entry);
}

void initheader(void *p) {
	memset(p,0,sizeof(list));
}