Initial stab at Venti.

src/cmd/venti/findscore.c

@@ -0,0 +1,132 @@
+#include "stdinc.h"
+#include "dat.h"
+#include "fns.h"
+
+enum
+{
+	ClumpChunks	= 32*1024
+};
+
+static int	verbose;
+
+int
+clumpinfoeq(ClumpInfo *c, ClumpInfo *d)
+{
+	return c->type == d->type
+		&& c->size == d->size
+		&& c->uncsize == d->uncsize
+		&& scorecmp(c->score, d->score)==0;
+}
+
+/*
+ * synchronize the clump info directory with
+ * with the clumps actually stored in the arena.
+ * the directory should be at least as up to date
+ * as the arena's trailer.
+ *
+ * checks/updates at most n clumps.
+ *
+ * returns 1 if ok, -1 if an error occured, 0 if blocks were updated
+ */
+int
+findscore(Arena *arena, uchar *score)
+{
+	IEntry ie;
+	ClumpInfo *ci, *cis;
+	u64int a;
+	u32int clump;
+	int i, n, found;
+
+//ZZZ remove fprint?
+	if(arena->clumps)
+		fprint(2, "reading directory for arena=%s with %d entries\n", arena->name, arena->clumps);
+
+	cis = MKN(ClumpInfo, ClumpChunks);
+	found = 0;
+	a = 0;
+	memset(&ie, 0, sizeof(IEntry));
+	for(clump = 0; clump < arena->clumps; clump += n){
+		n = ClumpChunks;
+		if(n > arena->clumps - clump)
+			n = arena->clumps - clump;
+		if(readclumpinfos(arena, clump, cis, n) != n){
+			seterr(EOk, "arena directory read failed: %r");
+			break;
+		}
+
+		for(i = 0; i < n; i++){
+			ci = &cis[i];
+			if(scorecmp(score, ci->score)==0){
+				fprint(2, "found at clump=%d with type=%d size=%d csize=%d position=%lld\n",
+					clump + i, ci->type, ci->uncsize, ci->size, a);
+				found++;
+			}
+			a += ci->size + ClumpSize;
+		}
+	}
+	free(cis);
+	return found;
+}
+
+void
+usage(void)
+{
+	fprint(2, "usage: findscore [-v] arenafile score\n");
+	threadexitsall(0);
+}
+
+void
+threadmain(int argc, char *argv[])
+{
+	ArenaPart *ap;
+	Part *part;
+	char *file;
+	u8int score[VtScoreSize];
+	int i, found;
+
+	fmtinstall('V', vtscorefmt);
+	statsinit();
+
+	ARGBEGIN{
+	case 'v':
+		verbose++;
+		break;
+	default:
+		usage();
+		break;
+	}ARGEND
+
+	readonly = 1;
+
+	if(argc != 2)
+		usage();
+
+	file = argv[0];
+	if(strscore(argv[1], score) < 0)
+		sysfatal("bad score %s\n", argv[1]);
+
+	part = initpart(file, 0);
+	if(part == nil)
+		sysfatal("can't open partition %s: %r", file);
+
+	ap = initarenapart(part);
+	if(ap == nil)
+		sysfatal("can't initialize arena partition in %s: %r", file);
+
+	if(verbose > 1){
+		printarenapart(2, ap);
+		fprint(2, "\n");
+	}
+
+	initdcache(8 * MaxDiskBlock);
+
+	found = 0;
+	for(i = 0; i < ap->narenas; i++)
+		found += findscore(ap->arenas[i], score);
+
+	print("found %d occurances of %V\n", found, score);
+
+	if(verbose > 1)
+		printstats();
+	threadexitsall(0);
+}