Initial stab at Venti.

src/cmd/venti/clumpstats.c

@@ -0,0 +1,128 @@
+#include "stdinc.h"
+#include "dat.h"
+#include "fns.h"
+
+int	count[VtMaxLumpSize][VtMaxType];
+
+enum
+{
+	ClumpChunks	= 32*1024
+};
+
+static int
+readarenainfo(Arena *arena)
+{
+	ClumpInfo *ci, *cis;
+	u32int clump;
+	int i, n, ok;
+
+	if(arena->clumps)
+		fprint(2, "reading directory for arena=%s with %d entries\n", arena->name, arena->clumps);
+
+	cis = MKN(ClumpInfo, ClumpChunks);
+	ok = 0;
+	for(clump = 0; clump < arena->clumps; clump += n){
+		n = ClumpChunks;
+
+		if(n > arena->clumps - clump)
+			n = arena->clumps - clump;
+
+		if((i=readclumpinfos(arena, clump, cis, n)) != n){
+			seterr(EOk, "arena directory read failed %d not %d: %r", i, n);
+			ok = -1;
+			break;
+		}
+
+		for(i = 0; i < n; i++){
+			ci = &cis[i];
+			if(ci->type >= VtMaxType || ci->uncsize >= VtMaxLumpSize) {
+				fprint(2, "bad clump: %d: type = %d: size = %d\n", clump+i, ci->type, ci->uncsize);
+				continue;
+			}
+if(ci->uncsize == 422)
+print("%s: %d: %V\n", arena->name, clump+i, ci->score);
+			count[ci->uncsize][ci->type]++;
+		}
+	}
+	free(cis);
+	if(ok < 0)
+		return TWID32;
+	return clump;
+}
+
+static void
+clumpstats(Index *ix)
+{
+	int ok;
+	ulong clumps, n;
+	int i, j, t;
+
+	ok = 0;
+	clumps = 0;
+	for(i = 0; i < ix->narenas; i++){
+		n = readarenainfo(ix->arenas[i]);
+		if(n == TWID32){
+			ok = -1;
+			break;
+		}
+		clumps += n;
+	}
+
+	if(ok < 0)
+		return;
+
+	print("clumps = %ld\n", clumps);
+	for(i=0; i<VtMaxLumpSize; i++) {
+		t = 0;
+		for(j=0; j<VtMaxType; j++)
+			t += count[i][j];
+		if(t == 0)
+			continue;
+		print("%d\t%d", i, t);
+		for(j=0; j<VtMaxType; j++)
+			print("\t%d", count[i][j]);
+		print("\n");
+	}
+}
+
+
+void
+usage(void)
+{
+	fprint(2, "usage: clumpstats [-B blockcachesize] config\n");
+	threadexitsall(0);
+}
+
+void
+threadmain(int argc, char *argv[])
+{
+	u32int bcmem;
+
+	bcmem = 0;
+
+	ARGBEGIN{
+	case 'B':
+		bcmem = unittoull(ARGF());
+		break;
+	default:
+		usage();
+		break;
+	}ARGEND
+
+	readonly = 1;
+
+	if(argc != 1)
+		usage();
+
+	if(initventi(argv[0]) < 0)
+		sysfatal("can't init venti: %r");
+
+	if(bcmem < maxblocksize * (mainindex->narenas + mainindex->nsects * 4 + 16))
+		bcmem = maxblocksize * (mainindex->narenas + mainindex->nsects * 4 + 16);
+	fprint(2, "initialize %d bytes of disk block cache\n", bcmem);
+	initdcache(bcmem);
+
+	clumpstats(mainindex);
+	
+	threadexitsall(0);
+}