Initial stab at Venti.

src/cmd/venti/copy.c

@@ -0,0 +1,169 @@
+#include "stdinc.h"
+#include "dat.h"
+#include "fns.h"
+
+int fast;
+
+VtConn *zsrc, *zdst;
+
+void
+usage(void)
+{
+	fprint(2, "usage: copy src-host dst-host score [type]\n");
+	threadexitsall("usage");
+}
+
+int
+parsescore(uchar *score, char *buf, int n)
+{
+	int i, c;
+
+	memset(score, 0, VtScoreSize);
+
+	if(n < VtScoreSize*2)
+		return -1;
+	for(i=0; i<VtScoreSize*2; i++) {
+		if(buf[i] >= '0' && buf[i] <= '9')
+			c = buf[i] - '0';
+		else if(buf[i] >= 'a' && buf[i] <= 'f')
+			c = buf[i] - 'a' + 10;
+		else if(buf[i] >= 'A' && buf[i] <= 'F')
+			c = buf[i] - 'A' + 10;
+		else {
+			return -1;
+		}
+
+		if((i & 1) == 0)
+			c <<= 4;
+	
+		score[i>>1] |= c;
+	}
+	return 0;
+}
+
+void
+walk(uchar score[VtScoreSize], uint type, int base)
+{
+	int i, n, sub;
+	uchar *buf;
+	VtEntry e;
+	VtRoot root;
+
+	if(memcmp(score, vtzeroscore, VtScoreSize) == 0)
+		return;
+
+	buf = vtmallocz(VtMaxLumpSize);
+	if(fast && vtread(zdst, score, type, buf, VtMaxLumpSize) >= 0){
+		fprint(2, "skip %V\n", score);
+		free(buf);
+		return;
+	}
+
+	n = vtread(zsrc, score, type, buf, VtMaxLumpSize);
+	if(n < 0){
+		fprint(2, "warning: could not read block %V %d: %r", score, type);
+		return;
+	}
+
+	switch(type){
+	case VtRootType:
+		if(vtrootunpack(&root, buf) < 0){
+			fprint(2, "warning: could not unpack root in %V %d\n", score, type);
+			break;
+		}
+		walk(root.score, VtDirType, 0);
+		walk(root.prev, VtRootType, 0);
+		break;
+
+	case VtDirType:
+		for(i=0; i<n/VtEntrySize; i++){
+			if(vtentryunpack(&e, buf, i) < 0){
+				fprint(2, "warning: could not unpack entry #%d in %V %d\n", i, score, type);
+				continue;
+			}
+			if(!(e.flags & VtEntryActive))
+				continue;
+			if(e.flags&VtEntryDir)
+				base = VtDirType;
+			else
+				base = VtDataType;
+			sub = base | ((e.flags&VtEntryDepthMask)>>VtEntryDepthShift);
+			walk(e.score, sub, base);
+		}
+		break;
+
+	case VtDataType:
+		break;
+
+	default:	/* pointers */
+		for(i=0; i<n; i+=VtScoreSize)
+			if(memcmp(buf+i, vtzeroscore, VtScoreSize) != 0)
+				walk(buf+i, type-1, base);
+		break;
+	}
+
+	if(vtwrite(zdst, score, type, buf, n) < 0)
+		fprint(2, "warning: could not write block %V %d: %r", score, type);
+	free(buf);
+}
+
+void
+threadmain(int argc, char *argv[])
+{
+	int type, n;
+	uchar score[VtScoreSize];
+	uchar *buf;
+
+	ARGBEGIN{
+	case 'f':
+		fast = 1;
+		break;
+	default:
+		usage();
+		break;
+	}ARGEND
+
+	if(argc != 3 && argc != 4)
+		usage();
+
+	fmtinstall('V', vtscorefmt);
+
+	if(parsescore(score, argv[2], strlen(argv[2]) < 0))
+		sysfatal("could not parse score: %r");
+
+	buf = vtmallocz(VtMaxLumpSize);
+
+	zsrc = vtdial(argv[0]);
+	if(zsrc == nil)
+		sysfatal("could not dial src server: %r");
+	if(vtconnect(zsrc) < 0)
+		sysfatal("vtconnect src: %r");
+
+	zdst = vtdial(argv[1]);
+	if(zdst == nil)
+		sysfatal("could not dial dst server: %r");
+	if(vtconnect(zdst) < 0)
+		sysfatal("vtconnect dst: %r");
+
+	if(argc == 4){
+		type = atoi(argv[3]);
+		n = vtread(zsrc, score, type, buf, VtMaxLumpSize);
+		if(n < 0)
+			sysfatal("could not read block: %r");
+	}else{
+		for(type=0; type<VtMaxType; type++){
+			n = vtread(zsrc, score, type, buf, VtMaxLumpSize);
+			if(n >= 0)
+				break;
+		}
+		if(type == VtMaxType)
+			sysfatal("could not find block %V of any type", score);
+	}
+
+	walk(score, type, VtDirType);
+
+	if(vtsync(zdst) < 0)
+		sysfatal("could not sync dst server: %r");
+
+	threadexitsall(0);
+}