/* newsegment - create a new segment (only called here and in xlimage.c) */
SEGMENT *newsegment(int n)
{
SEGMENT *newseg;
/* allocate the new segment */
if ((newseg = (SEGMENT *)calloc(1,segsize(n))) == NULL)
return (NULL);
/* initialize the new segment */
newseg->sg_size = n;
newseg->sg_next = NULL;
if (segs)
lastseg->sg_next = newseg;
else
segs = newseg;
lastseg = newseg;
/* update the statistics */
total += (long)segsize(n);
nnodes += (long)n;
nfree += (long)n;
++nsegs;
/* return the new segment */
return (newseg);
}
//
// Free empty segments
//
LOCAL void freesegs()
{
SEGMENT *seg;
SEGMENT *next;
// Free up as many nodes as possible
gc();
// Reset free node tracking
fnodes = NIL;
nfree = 0L;
// Reset the last segment pointer
lastseg = NULL;
// Scan all segments
for (seg = segs; seg != NULL; seg = next) {
int n = seg->sg_size;
int empty = TRUE;
int i;
LVAL p;
// Check this segment for in-use nodes
p = &seg->sg_nodes[0];
for (i = n; --i >= 0; ++p) {
if (ntype(p) != FREE_NODE) {
empty = FALSE;
break;
}
}
// Retain pointer to next segment
next = seg->sg_next;
// Was the current segment empty?
if (empty) {
// Free the segment;
free((void *) seg);
// Unlink it from the list. No need to worry about a NULL lastseg
// pointer here since the fixnum and char segments will always exist
// at the head of the list and they will always have nodes. So, lastseg
// will have been set before we find any empty nodes.
lastseg->sg_next = next;
// Reduce the stats
total -= (long) segsize(n);
nsegs--;
nnodes -= n;
}
else {
// Not empty, so remember this node as the last segment
lastseg = seg;
// Add all of the free nodes in this segment to the free list
p = &seg->sg_nodes[0];
for (i = n; --i >= 0; ++p) {
if (ntype(p) == FREE_NODE) {
rplaca(p, NIL);
rplacd(p, fnodes);
fnodes = p;
nfree++;
}
}
}
}
}
int main(){
int t,n;
scanf("%u",&t);
while(t--){
switch(scanf("\n"),getchar()){
case 'M'://Move k
scanf("ove %u",&n);
for(curseg=head->next;
curseg!=null&&n>=segsize(*curseg);
n-=segsize(*curseg),curseg=curseg->next);
cur=curseg->begin+n;
break;
case 'I'://Insert n endl S
scanf("nsert %u",&n);
if(cur>curseg->begin){
new segment(curseg->begin,cur,curseg->last,curseg);
curseg->begin=cur;
}
cur=newc;
while(n--){
while((*newc=getchar())=='\n');
newc++;
}
curseg=new segment(cur,newc,curseg->last,curseg);
break;
case 'D'://Delete n
scanf("elete %u",&n);
if(cur!=curseg->begin){
new segment(curseg->begin,cur,curseg->last,curseg);
curseg->begin=cur;
}
while(curseg!=null&&n>=segsize(*curseg)){
n-=segsize(*curseg);
curseg=curseg->next;
delete curseg->last;
}
cur=curseg->begin+=n;
break;
case 'G'://Get n
scanf("et %u",&n);
tmpcur=cur; tmpcurseg=curseg;
while(curseg!=null&&n>=curseg->end-cur){
n-=curseg->end-cur;
fwrite(cur,1,curseg->end-cur,stdout);
curseg=curseg->next;
cur=curseg->begin;
}
fwrite(cur,1,n,stdout);
putchar('\n');
curseg=tmpcurseg;
cur=tmpcur;
break;
case 'P'://Prev
scanf("rev");
if(cur!=curseg->begin) cur--; else
curseg=curseg->last,cur=curseg->end-1;
break;
case 'N'://Next
scanf("ext");
if(++cur==curseg->end)
curseg=curseg->next,cur=curseg->begin;
break;
}
}
}
