stew

commit e8fcfc35bdb4da086200c9c08bf77adac4198a65
parent e2762aed174dde8f4022a6f6b756c9f037cf31d0
Author: rpa <rpa@grass>
Date:   Sun, 10 Sep 2023 00:04:10 +0000

src/wdb/update: a primitive db update tool

Diffstat:
M
src/wdb/mkfile
 | 
6
+++++-
A
src/wdb/update.c
 | 
99
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 104 insertions(+), 1 deletion(-)
diff --git a/src/wdb/mkfile b/src/wdb/mkfile
@@ -1,5 +1,9 @@
 </$objtype/mkfile
-TARG=search
+TARG=search update
 HFILES=wdb.h util.h
 OFILES=util.$O
 </sys/src/cmd/mkmany
+
+# LIB=../util/libutil.a$O ../tablist/libtablist.a$O
+
+# $O.update: update.$O $LIB
diff --git a/src/wdb/update.c b/src/wdb/update.c
@@ -0,0 +1,99 @@
+#include <u.h>
+#include <libc.h>
+#include <../util/util.h>
+#include <../tablist/tablist.h>
+enum {
+	BSize = 1024 * 8,
+	HSize = BSize / 2,
+};
+
+int db, bn;
+char *path, buf[BSize];
+TLdecoder *tldec;
+TLencoder *tlenc;
+Slice *query, *nodes;
+
+TLnode **
+find(TLnode *n)
+{
+	TLnode **v, *m;
+	int i;
+	if (n->name == nil) return nil;
+	for (i = 0; i < nodes->len; i++) {
+		v = slicegetp(nodes, i);
+		m = *v;
+		if (m->name == nil) continue;
+		if (memcmp(m->name->p, n->name->p, m->name->len) == 0)
+			return v;
+	}
+	return nil;
+}
+
+void
+update(TLnode *n)
+{
+	TLnode **v;
+	v = find(n);
+	if (v != nil) {
+		*v = n;
+	} else {
+		nodes = sliceappendp(nodes, 1, &n);
+	}
+}
+
+void
+usage(void)
+{
+	fprint(2, "usage %s db_file < node\n", argv0);
+	exits("usage");
+}
+
+void
+main(int argc, char *argv[])
+{
+
+	fprint(2, "hello\n");
+
+	int i;
+
+	ARGBEGIN {
+	default:
+		usage();
+	} ARGEND
+
+	if (argc != 1) usage();
+	path = argv[0];
+	db = open(path, OREAD);
+	if (db < 0) sysfatal("can't open db: %r");
+
+	fprint(2, "reading query\n");
+	tldec = initTLdecoder(nil);
+	while((bn = read(0, buf, BSize)) > 0) {
+		TLdecode(tldec, buf, bn);
+	}
+	if (bn < 0) sysfatal("%r");
+	query = tldec->nodes;
+	fprint(2, "qlen %d\n", query->len);
+
+	tldec = initTLdecoder(path);
+	while((bn = read(db, buf, BSize)) > 0) {
+		TLdecode(tldec, buf, bn);
+	}
+	if (bn < 0) sysfatal("%r");
+	nodes = tldec->nodes;
+	close(db);
+
+	for (i = 0; i < query->len; i++) {
+		TLnode **v;
+		v = slicegetp(query, i);
+		update(*v);
+	}
+
+	db = open(path, OWRITE | OTRUNC);
+	if (db < 0) sysfatal("%r");
+	tlenc = initTLencoder(nodes);
+	while((bn = TLencode(tlenc, buf, BSize)) > 0) {
+		bn = write(db, buf, bn);
+		if (bn < 0) sysfatal("%r");
+	}	
+}