checkout - eye candy.

This implements "eye candy" similar to the pack-object/unpack-object
to entertain users while a large tree is being checked out after
a clone or a pull.

Signed-off-by: Junio C Hamano <junkio@cox.net>

git-clone.sh

@@ -253,7 +253,7 @@ Pull: $head_points_at:$origin" &&
 
 	case "$no_checkout" in
 	'')
-		git checkout
+		git-read-tree -m -u -v HEAD HEAD
 	esac
 fi
 

git-merge.sh

@@ -130,7 +130,7 @@ case "$#,$common,$no_commit" in
 	echo "Updating from $head to $1."
 	git-update-index --refresh 2>/dev/null
 	new_head=$(git-rev-parse --verify "$1^0") &&
-	git-read-tree -u -m $head "$new_head" &&
+	git-read-tree -u -v -m $head "$new_head" &&
 	finish "$new_head" "Fast forward"
 	dropsave
 	exit 0
@@ -146,7 +146,7 @@ case "$#,$common,$no_commit" in
 
 	echo "Trying really trivial in-index merge..."
 	git-update-index --refresh 2>/dev/null
-	if git-read-tree --trivial -m -u $common $head "$1" &&
+	if git-read-tree --trivial -m -u -v $common $head "$1" &&
 	   result_tree=$(git-write-tree)
 	then
 	    echo "Wonderful."

read-tree.c

@@ -9,6 +9,8 @@
 
 #include "object.h"
 #include "tree.h"
+#include <sys/time.h>
+#include <signal.h>
 
 static int merge = 0;
 static int update = 0;
@@ -16,6 +18,8 @@ static int index_only = 0;
 static int nontrivial_merge = 0;
 static int trivial_merges_only = 0;
 static int aggressive = 0;
+static int verbose_update = 0;
+static volatile int progress_update = 0;
 
 static int head_idx = -1;
 static int merge_size = 0;
@@ -267,6 +271,12 @@ static void unlink_entry(char *name)
 	}
 }
 
+static void progress_interval(int signum)
+{
+	signal(SIGALRM, progress_interval);
+	progress_update = 1;
+}
+
 static void check_updates(struct cache_entry **src, int nr)
 {
 	static struct checkout state = {
@@ -276,8 +286,49 @@ static void check_updates(struct cache_entry **src, int nr)
 		.refresh_cache = 1,
 	};
 	unsigned short mask = htons(CE_UPDATE);
+	unsigned last_percent = 200, cnt = 0, total = 0;
+
+	if (update && verbose_update) {
+		struct itimerval v;
+
+		for (total = cnt = 0; cnt < nr; cnt++) {
+			struct cache_entry *ce = src[cnt];
+			if (!ce->ce_mode || ce->ce_flags & mask)
+				total++;
+		}
+
+		/* Don't bother doing this for very small updates */
+		if (total < 250)
+			total = 0;
+
+		if (total) {
+			v.it_interval.tv_sec = 1;
+			v.it_interval.tv_usec = 0;
+			v.it_value = v.it_interval;
+			signal(SIGALRM, progress_interval);
+			setitimer(ITIMER_REAL, &v, NULL);
+			fprintf(stderr, "Checking files out...\n");
+			progress_update = 1;
+		}
+		cnt = 0;
+	}
+
 	while (nr--) {
 		struct cache_entry *ce = *src++;
+
+		if (total) {
+			if (!ce->ce_mode || ce->ce_flags & mask) {
+				unsigned percent;
+				cnt++;
+				percent = (cnt * 100) / total;
+				if (percent != last_percent ||
+				    progress_update) {
+					fprintf(stderr, "%4u%% (%u/%u) done\r",
+						percent, cnt, total);
+					last_percent = percent;
+				}
+			}
+		}
 		if (!ce->ce_mode) {
 			if (update)
 				unlink_entry(ce->name);
@@ -289,6 +340,10 @@ static void check_updates(struct cache_entry **src, int nr)
 				checkout_entry(ce, &state);
 		}
 	}
+	if (total) {
+		fputc('\n', stderr);
+		signal(SIGALRM, SIG_IGN);
+	}
 }
 
 static int unpack_trees(merge_fn_t fn)
@@ -680,6 +735,11 @@ int main(int argc, char **argv)
 			continue;
 		}
 
+		if (!strcmp(arg, "-v")) {
+			verbose_update = 1;
+			continue;
+		}
+
 		/* "-i" means "index only", meaning that a merge will
 		 * not even look at the working tree.
 		 */