From d1f529f46f957c78a3db73b42c2fcd2d3c9f8a34 Mon Sep 17 00:00:00 2001
From: rsc <devnull@localhost>
Date: Sat, 29 Oct 2005 16:26:32 +0000
Subject: Thanks to John Cummings.

---
 src/cmd/upas/bayes/msgclass.c | 296 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 296 insertions(+)
 create mode 100644 src/cmd/upas/bayes/msgclass.c

(limited to 'src/cmd/upas/bayes/msgclass.c')

diff --git a/src/cmd/upas/bayes/msgclass.c b/src/cmd/upas/bayes/msgclass.c
new file mode 100644
index 00000000..bd3c571c
--- /dev/null
+++ b/src/cmd/upas/bayes/msgclass.c
@@ -0,0 +1,296 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <ctype.h>
+#include "msgdb.h"
+
+void
+usage(void)
+{
+	fprint(2, "usage: upas/msgclass [-a] [-d name dbfile]... [-l lockfile] [-m mul] [-t thresh] [tokenfile ...]\n");
+	exits("usage");
+}
+
+enum
+{
+	MAXBEST = 32,
+	MAXLEN = 64,
+	MAXTAB = 256,
+};
+
+typedef struct Ndb Ndb;
+struct Ndb
+{
+	char *name;
+	char *file;
+	Msgdb *db;
+	double p;
+	long nmsg;
+};
+
+typedef struct Word Word;
+struct Word
+{
+	char s[MAXLEN];
+	int count[MAXTAB];
+	double p[MAXTAB];
+	double mp;
+	int mi; /* w.p[w.mi] = w.mp */
+	int nmsg;
+};
+
+Ndb db[MAXTAB];
+int ndb;
+
+int add;
+int mul;
+Msgdb *indb;
+
+Word best[MAXBEST];
+int mbest = 15;
+int nbest;
+
+void process(Biobuf*, char*);
+void lockfile(char*);
+
+void
+noteword(Word *w, char *s)
+{
+	int i;
+
+	for(i=nbest-1; i>=0; i--)
+		if(w->mp < best[i].mp)
+			break;
+	i++;
+
+	if(i >= mbest)
+		return;
+	if(nbest == mbest)
+		nbest--;
+	if(i < nbest)
+		memmove(&best[i+1], &best[i], (nbest-i)*sizeof(best[0]));
+	best[i] = *w;
+	strecpy(best[i].s, best[i].s+MAXLEN, s);
+	nbest++;
+}
+
+void
+main(int argc, char **argv)
+{
+	int i, bad, m, tot, nn, j;
+	Biobuf bin, *b, bout;
+	char *s, *lf;
+	double totp, p, thresh;
+	long n;
+	Word w;
+
+	lf = nil;
+	thresh = 0;
+	ARGBEGIN{
+	case 'a':
+		add = 1;
+		break;
+	case 'd':
+		if(ndb >= MAXTAB)
+			sysfatal("too many db classes");
+		db[ndb].name = EARGF(usage());
+		db[ndb].file = EARGF(usage());
+		ndb++;
+		break;
+	case 'l':
+		lf = EARGF(usage());
+		break;
+	case 'm':
+		mul = atoi(EARGF(usage()));
+		break;
+	case 't':
+		thresh = atof(EARGF(usage()));
+		break;
+	default:
+		usage();
+	}ARGEND
+
+	if(ndb == 0){
+		fprint(2, "must have at least one -d option\n");
+		usage();
+	}
+
+	indb = mdopen(nil, 1);
+	if(argc == 0){
+		Binit(&bin, 0, OREAD);
+		process(&bin, "<stdin>");
+		Bterm(&bin);
+	}else{
+		bad = 0;
+		for(i=0; i<argc; i++){
+			if((b = Bopen(argv[i], OREAD)) == nil){
+				fprint(2, "opening %s: %r\n", argv[i]);
+				bad = 1;
+				continue;
+			}
+			process(b, argv[i]);
+			Bterm(b);
+		}
+		if(bad)
+			exits("open inputs");
+	}
+
+	lockfile(lf);
+	bad = 0;
+	for(i=0; i<ndb; i++){
+		if((db[i].db = mdopen(db[i].file, 0)) == nil){
+			fprint(2, "opendb %s: %r\n", db[i].file);
+			bad = 1;
+		}
+		db[i].nmsg = mdget(db[i].db, "*From*");
+	}
+	if(bad)
+		exits("open databases");
+
+	/* run conditional probabilities of input words, getting 15 most specific */
+	mdenum(indb);
+	nbest = 0;
+	while(mdnext(indb, &s, &n) >= 0){
+		tot = 0;
+		totp = 0.0;
+		for(i=0; i<ndb; i++){
+			nn = mdget(db[i].db, s)*(i==0 ? 3 : 1);
+			tot += nn;
+			w.count[i] = nn;
+			p = w.count[i]/(double)db[i].nmsg;
+			if(p >= 1.0)
+				p = 1.0;
+			w.p[i] = p;
+			totp += p;
+		}
+//fprint(2, "%s tot %d totp %g\n", s, tot, totp);
+		if(tot < 2)
+			continue;
+		w.mp = 0.0;
+		for(i=0; i<ndb; i++){
+			p = w.p[i];
+			p /= totp;
+			if(p < 0.001)
+				p = 0.001;
+			else if(p > 0.999)
+				p = 0.999;
+			if(p > w.mp){
+				w.mp = p;
+				w.mi = i;
+			}
+			w.p[i] = p;
+		}
+		noteword(&w, s);
+	}
+
+	/* compute conditional probabilities of message classes using 15 most specific */
+	totp = 0.0;
+	for(i=0; i<ndb; i++){
+		p = 1.0;
+		for(j=0; j<nbest; j++)
+			p *= best[j].p[i];
+		db[i].p = p;
+		totp += p;
+	}
+	for(i=0; i<ndb; i++)
+		db[i].p /= totp;
+	m = 0;
+	for(i=1; i<ndb; i++)
+		if(db[i].p > db[m].p)
+			m = i;
+
+	Binit(&bout, 1, OWRITE);
+	if(db[m].p < thresh)
+		m = -1;
+	if(m >= 0)
+		Bprint(&bout, "%s", db[m].name);
+	else
+		Bprint(&bout, "inconclusive");
+	for(j=0; j<ndb; j++)
+		Bprint(&bout, " %s=%g", db[j].name, db[j].p);
+	Bprint(&bout, "\n");
+	for(i=0; i<nbest; i++){
+		Bprint(&bout, "%s", best[i].s);
+		for(j=0; j<ndb; j++)
+			Bprint(&bout, " %s=%g", db[j].name, best[i].p[j]);
+		Bprint(&bout, "\n");
+	}
+		Bprint(&bout, "%s %g\n", best[i].s, best[i].p[m]);
+	Bterm(&bout);
+
+	if(m >= 0 && add){
+		mdenum(indb);
+		while(mdnext(indb, &s, &n) >= 0)
+			mdput(db[m].db, s, mdget(db[m].db, s)+n*mul);
+		mdclose(db[m].db);
+	}
+	exits(nil);
+}
+
+void
+process(Biobuf *b, char*)
+{
+	char *s;
+	char *p;
+	long n;
+
+	while((s = Brdline(b, '\n')) != nil){
+		s[Blinelen(b)-1] = 0;
+		if((p = strrchr(s, ' ')) != nil){
+			*p++ = 0;
+			n = atoi(p);
+		}else
+			n = 1;
+		mdput(indb, s, mdget(indb, s)+n);
+	}
+}
+
+int tpid;
+void
+killtickle(void)
+{
+	postnote(PNPROC, tpid, "die");
+}
+
+void
+lockfile(char *s)
+{
+	int fd, t, w;
+	char err[ERRMAX];
+
+	if(s == nil)
+		return;
+	w = 50;
+	t = 0;
+	for(;;){
+		fd = open(s, OREAD);
+		if(fd >= 0)
+			break;
+		rerrstr(err, sizeof err);
+		if(strstr(err, "file is locked")==nil && strstr(err, "exclusive lock")==nil))
+			break;
+		sleep(w);
+		t += w;
+		if(w < 1000)
+			w = (w*3)/2;
+		if(t > 120*1000)
+			break;
+	}
+	if(fd < 0)
+		sysfatal("could not lock %s", s);
+	switch(tpid = fork()){
+	case -1:
+		sysfatal("fork: %r");
+	case 0:
+		for(;;){
+			sleep(30*1000);
+			free(dirfstat(fd));
+		}
+		_exits(nil);
+	default:
+		break;
+	}
+	close(fd);
+	atexit(killtickle);
+}
+
-- 
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