Make "git clone" less of a deathly quiet experience

It used to be that "git-unpack-objects" would give nice percentages, but
now that we don't unpack the initial clone pack any more, it doesn't. And
I'd love to do that nice percentage view in the pack objects downloader
too, but the thing doesn't even read the pack header, much less know how
much it's going to get, so I was lazy and didn't.

Instead, it at least prints out how much data it's gotten, and what the
packing speed is. Which makes the user realize that it's actually doing
something useful instead of sitting there silently (and if the recipient
knows how large the final result is, he can at least make a guess about
when it migt be done).

So with this patch, I get something like this on my DSL line:

	[torvalds@g5 ~]$ time git clone master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 clone-test
	Packing 188543 objects
	  48.398MB  (154 kB/s)

where even the speed approximation seems to be roughtly correct (even
though my algorithm is a truly stupid one, and only really gives "speed in
the last half second or so").

Anyway, _something_ like this is definitely needed. It could certainly be
better (if it showed the same kind of thing that git-unpack-objects did,
that would be much nicer, but would require parsing the object stream as
it comes in). But this is  big step forward, I think.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

cache.h

@@ -348,6 +348,6 @@ extern int copy_fd(int ifd, int ofd);
 
 /* Finish off pack transfer receiving end */
 extern int receive_unpack_pack(int fd[2], const char *me, int quiet);
-extern int receive_keep_pack(int fd[2], const char *me);
+extern int receive_keep_pack(int fd[2], const char *me, int quiet);
 
 #endif /* CACHE_H */

clone-pack.c

@@ -6,6 +6,8 @@ static const char clone_pack_usage[] =
 "git-clone-pack [--exec=<git-upload-pack>] [<host>:]<directory> [<heads>]*";
 static const char *exec = "git-upload-pack";
 
+static int quiet = 0;
+
 static void clone_handshake(int fd[2], struct ref *ref)
 {
 	unsigned char sha1[20];
@@ -123,7 +125,9 @@ static int clone_pack(int fd[2], int nr_match, char **match)
 	}
 	clone_handshake(fd, refs);
 
-	status = receive_keep_pack(fd, "git-clone-pack");
+	if (!quiet)
+		fprintf(stderr, "Generating pack ...\r");
+	status = receive_keep_pack(fd, "git-clone-pack", quiet);
 
 	if (!status) {
 		if (nr_match == 0)
@@ -154,8 +158,10 @@ int main(int argc, char **argv)
 		char *arg = argv[i];
 
 		if (*arg == '-') {
-			if (!strcmp("-q", arg))
+			if (!strcmp("-q", arg)) {
+				quiet = 1;
 				continue;
+			}
 			if (!strncmp("--exec=", arg, 7)) {
 				exec = arg + 7;
 				continue;

fetch-clone.c

@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "exec_cmd.h"
 #include <sys/wait.h>
+#include <sys/time.h>
 
 static int finish_pack(const char *pack_tmp_name, const char *me)
 {
@@ -129,10 +130,12 @@ int receive_unpack_pack(int fd[2], const char *me, int quiet)
 	die("git-unpack-objects died of unnatural causes %d", status);
 }
 
-int receive_keep_pack(int fd[2], const char *me)
+int receive_keep_pack(int fd[2], const char *me, int quiet)
 {
 	char tmpfile[PATH_MAX];
 	int ofd, ifd;
+	unsigned long total;
+	static struct timeval prev_tv;
 
 	ifd = fd[0];
 	snprintf(tmpfile, sizeof(tmpfile),
@@ -141,6 +144,8 @@ int receive_keep_pack(int fd[2], const char *me)
 	if (ofd < 0)
 		return error("unable to create temporary file %s", tmpfile);
 
+	gettimeofday(&prev_tv, NULL);
+	total = 0;
 	while (1) {
 		char buf[8192];
 		ssize_t sz, wsz, pos;
@@ -165,6 +170,27 @@ int receive_keep_pack(int fd[2], const char *me)
 			}
 			pos += wsz;
 		}
+		total += sz;
+		if (!quiet) {
+			static unsigned long last;
+			struct timeval tv;
+			unsigned long diff = total - last;
+			/* not really "msecs", but a power-of-two millisec (1/1024th of a sec) */
+			unsigned long msecs;
+
+			gettimeofday(&tv, NULL);
+			msecs = tv.tv_sec - prev_tv.tv_sec;
+			msecs <<= 10;
+			msecs += (int)(tv.tv_usec - prev_tv.tv_usec) >> 10;
+			if (msecs > 500) {
+				prev_tv = tv;
+				last = total;
+				fprintf(stderr, "%4lu.%03luMB  (%lu kB/s)        \r",
+					total >> 20,
+					1000*((total >> 10) & 1023)>>10,
+					diff / msecs );
+			}
+		}
 	}
 	close(ofd);
 	return finish_pack(tmpfile, me);

fetch-pack.c

@@ -378,7 +378,7 @@ static int fetch_pack(int fd[2], int nr_match, char **match)
 		fprintf(stderr, "warning: no common commits\n");
 
 	if (keep_pack)
-		status = receive_keep_pack(fd, "git-fetch-pack");
+		status = receive_keep_pack(fd, "git-fetch-pack", quiet);
 	else
 		status = receive_unpack_pack(fd, "git-fetch-pack", quiet);