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<title>/usr/web/sources/contrib/noselasd/fibfs.c - Plan 9 from Bell Labs</title>


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<a href="/plan9/">Plan 9 from Bell Labs</a>’s /usr/web/sources/contrib/noselasd/fibfs.c


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Copyright © 2009 Alcatel-Lucent. 
Distributed under the
<a href="/plan9/license.html">Lucent Public License version 1.02</a>.
 
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/* fs example. Does it get any better ? */

#include <u.h>
#include <libc.h>
#include <mp.h>
#include <fcall.h>
#include <thread.h>
#include <9p.h>

typedef struct FibState {
mpint *current;
mpint *last;
}FibState;

Tree *fibtree;

static void freefibstate(FibState *state)
{
mpfree(state->last);
mpfree(state->current);
free(state);
}

static FibState*
allocfibstate(void)
{
FibState *new;

new = emalloc9p(sizeof *new);
new->current = itomp(1,nil);
new->last = itomp(0,nil);
if(new->current == nil || new->last == nil) {
freefibstate(new);
new = nil;
}

return new;
}

static u32int
nextfib(FibState *state,char *buf,u32int maxlen)
{
int len;

mpint* next = mpnew(96);
if(next == nil)
return 0;

mptoa(state->current,10,buf,maxlen -1);

mpadd(state->current,state->last,next);
mpfree(state->last);
state->last = state->current;
state->current = next;
len = strlen(buf);
buf[len] = '\n';
return len + 1;
}

static void
fibread(Req *r)
{
if(r->ifcall.count < 2) {
respond(r,"Insufficient space");
return;
}

if(r->fid->aux == nil)
r->fid->aux = allocfibstate();

if(r->fid->aux == nil) {
respond(r,"Out of memory");
return;
}

r->ofcall.count = nextfib(r->fid->aux,r->ofcall.data,r->ifcall.count);
respond(r,nil);
}

static void
fibdestroyfid(Fid *f)
{
FibState *state = f->aux;
if(state)
freefibstate(state);
}

Srv fs = {
.read = fibread,
.destroyfid = fibdestroyfid
};

static void usage(void)
{
fprint(2,"usage: fibfs [-D] [-m mntpt]\n");
exits("usage");
}

void
main(int argc,char *argv[])
{
char *mntpt = ".";

ARGBEGIN{
case 'D':
chatty9p++;
break;
case 'm':
mntpt = EARGF(usage());
break;

}ARGEND;

fs.tree = fibtree = alloctree("none","none",DMDIR|0555,nil);
closefile(createfile(fibtree->root,"fibs","none",0444,nil));
postmountsrv(&fs,nil,mntpt,MAFTER);

exits(nil);
}

/*yes.*/

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