shithub: rngfs

Download patch

ref: 4ac4dc82da5199dd156f2c0c103f614c0e1d35c7
author: kvik <kvik@a-b.xyz>
date: Sun Jun 7 17:07:40 EDT 2020

Here begins history.

--- /dev/null	Thu Dec 31 12:39:09 2020
+++ b/mkfile	Sun Jun  7 17:07:40 2020
@@ -0,0 +1,20 @@
+</$objtype/mkfile
+
+BIN=/bin
+TARG=rngfs
+OFILES=rngfs.$O
+
+all:V:
+
+test:V:
+	rngfs
+	<>[3]/mnt/random/integer {
+			echo range 5 10 >[1=3]
+			<[0=3] sed 999q | awk '$1 < 5 || $1 > 10 {exit $1}'
+	}
+	<>[3]/mnt/random/real {
+			echo range 5.351115 10.5215 >[1=3]
+			<[0=3] sed 999q | awk '$1 < 5.351115 || $1 > 10.5215 {exit $1}'
+	}
+
+</sys/src/cmd/mkone
--- /dev/null	Thu Dec 31 12:39:09 2020
+++ b/rngfs.c	Sun Jun  7 17:07:40 2020
@@ -0,0 +1,264 @@
+#include <u.h>
+#include <libc.h>
+#include <fcall.h>
+#include <thread.h>
+#include <9p.h>
+
+void
+usage(void)
+{
+	fprint(2, "%s [-D] [-m mtpt] [-s srv]\n", argv0);
+	exits("usage");
+}
+
+enum {
+	Qroot,
+		Qinteger,
+		Qreal,
+};
+
+typedef struct F {
+	char *name;
+	Qid qid;
+	ulong mode;
+} F;
+
+typedef struct Fstate {
+	/* range [min, max) */
+	union {long i; double d;} min;
+	union {long i; double d;} max;
+} Fstate;
+
+F root = {
+	"/", {Qroot, 0, QTDIR}, 0555|DMDIR
+};
+F roottab[] = {
+	"integer", {Qinteger, 0, QTFILE}, 0444,
+	"real", {Qreal, 0, QTFILE}, 0444,
+};
+
+enum {Cmdrange};
+Cmdtab cmd[] = {
+	Cmdrange, "range", 3,
+};
+
+F*
+filebypath(uvlong path)
+{
+	int i;
+
+	if(path == Qroot)
+		return &root;
+	for(i = 0; i < nelem(roottab); i++)
+		if(path == roottab[i].qid.path)
+			return &roottab[i];
+	return nil;
+}
+
+void
+xattach(Req *r)
+{
+	r->fid->qid = filebypath(Qroot)->qid;
+	r->ofcall.qid = r->fid->qid;
+	respond(r, nil);
+}
+
+char*
+xwalk1(Fid *fid, char *name, Qid *qid)
+{
+	int i;
+	
+	switch(fid->qid.path){
+	case Qroot:
+		for(i = 0; i < nelem(roottab); i++){
+			if(strcmp(roottab[i].name, name) == 0){
+				*qid = roottab[i].qid;
+				fid->qid = *qid;
+				return nil;
+			}
+		}
+		if(strcmp("..", name) == 0){
+			*qid = root.qid;
+			fid->qid = *qid;
+			return nil;
+		}
+		break;
+	}
+	return "not found";
+}
+
+void
+xopen(Req *r)
+{
+	uvlong path = r->fid->qid.path;
+	Fstate *st;
+
+	st = emalloc9p(sizeof(Fstate));
+	r->fid->aux = st;
+	switch(path){
+	case Qinteger:
+		st->min.i = 0L;
+		st->max.i = 0x7fffffffL;
+		break;
+	case Qreal:
+		st->min.d = 0.0;
+		st->max.d = 1.0;
+		break;
+	}
+	respond(r, nil);
+}
+
+void
+xdestroyfid(Fid *fid)
+{
+	if(fid->aux != nil)
+		free(fid->aux);
+}
+
+void
+fillstat(Dir *d, uvlong path, char *user)
+{
+	F *f;
+
+	f = filebypath(path);
+	d->name = estrdup9p(f->name);
+	d->qid = f->qid;
+	d->mode = f->mode;
+	d->uid = estrdup9p(user);
+	d->gid = estrdup9p(user);
+	d->muid = estrdup9p(user);
+	d->length = 0;
+	d->atime = time(0);
+	d->mtime = time(0);
+}
+
+void
+xstat(Req *r)
+{
+	fillstat(&r->d, r->fid->qid.path, r->fid->uid);
+	respond(r, nil);
+	return;
+}
+
+int
+rootgen(int n, Dir *d, void *aux)
+{
+	Req *r = aux;
+
+	if(n >= nelem(roottab))
+		return -1;
+	fillstat(d, roottab[n].qid.path, r->fid->uid);
+	return 0;
+}
+
+long
+randominteger(long min, long max)
+{
+	if(min > max){int t = min; min = max; max = t;}
+	return min+((max-min)/(double)0x7fffffff*lrand());
+}
+
+double
+randomreal(double min, double max)
+{
+	if(min > max){double t = min; min = max; max = t;}
+	return min+(max-min)*frand();
+}
+
+void
+xread(Req *r)
+{
+	char buf[128];
+	int n = 0;
+	uvlong path = r->fid->qid.path;
+	Fstate *fs = r->fid->aux;
+
+	if(path == Qroot){
+		dirread9p(r, rootgen, r);
+		respond(r, nil);
+		return;
+	}
+
+	switch(path){
+	case Qinteger:
+		n = snprint(buf, sizeof buf, "%ld\n",
+			randominteger(fs->min.i, fs->max.i));
+		break;
+	case Qreal:
+		n = snprint(buf, sizeof buf, "%f\n",
+			randomreal(fs->min.d, fs->max.d));
+		break;
+	}
+	if(r->ifcall.count < n)
+		n = r->ifcall.count;
+	r->ofcall.count = n;
+	memmove(r->ofcall.data, buf, n);
+	respond(r, nil);
+}
+
+void
+xwrite(Req *r)
+{
+	uvlong path = r->fid->qid.path;
+	Cmdbuf *cb;
+	Cmdtab *cp;
+	Fstate *fs = r->fid->aux;
+
+	cb = parsecmd(r->ifcall.data, r->ifcall.count);
+	cp = lookupcmd(cb, cmd, nelem(cmd));
+	if(cp == nil){
+		respondcmderror(r, cb, "%r");
+		return;
+	}
+	switch(cp->index){
+	case Cmdrange:
+		switch(path){
+		case Qinteger:
+			fs->min.i = strtol(cb->f[1], nil, 10);
+			fs->max.i = strtol(cb->f[2], nil, 10);
+			break;
+		case Qreal:
+			fs->min.d = strtod(cb->f[1], nil);
+			fs->max.d = strtod(cb->f[1], nil);
+		}
+		break;
+	}
+	respond(r, nil);
+}
+
+Srv fileserver = {
+	.attach = xattach,
+	.walk1 = xwalk1,
+	.open = xopen,
+	.stat = xstat,
+	.read = xread,
+	.write = xwrite,
+	
+	.destroyfid = xdestroyfid,
+};
+
+void
+main(int argc, char *argv[])
+{
+	char *mtpt, *srvn;
+
+	mtpt = "/mnt/random";
+	srvn = nil;
+	ARGBEGIN{
+	case 'm':
+		mtpt = EARGF(usage());
+		break;
+	case 's':
+		srvn = EARGF(usage());
+		break;
+	case 'D':
+		chatty9p++;
+		break;
+	default:
+		usage();
+	}ARGEND;
+	
+	srand(time(0));
+	postmountsrv(&fileserver, srvn, mtpt, MREPL);
+	exits(nil);
+}