sha1_file.c: the global packed_git variable static to the filesz/packed-git-static

This is a first step in making the codebase thread-safe.  By and
large, the operations which might benefit from threading are those
that work with pack files (e.g., checkout, blame), so the focus of
this patch is stop leaking the global list of pack files outside of
sha1_file.c.

The next step will be to control access to the list of pack files
with a mutex.  However, that alone is not enough to make pack file
access thread safe.  Even in a read-only operation, the window list
associated with each pack file will need to be controlled.
Additionally, the global counters in sha1_file.c will need to be
controlled.

This patch is a pure refactor with no functional changes, so it
shouldn't require any additional tests.  Adding the actual locks
will be a functional change, and will require additional tests.

[jc: with minimul style fixes before a full review]

Signed-off-by: Stefan Zager <szager@chromium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 28 insertions, 18 deletions

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 1affdd5e92..e55f0803a2 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -624,6 +624,29 @@ static struct option fsck_opts[] = {
 	OPT_END(),
 };
 
+struct verify_packs_data {
+	struct progress *progress;
+	uint32_t total;
+	uint32_t count;
+};
+
+static int count_packs(struct packed_git *p, void *data)
+{
+	struct verify_packs_data *vpd = (struct verify_packs_data *) data;
+	if (!open_pack_index(p))
+		vpd->total++;
+	return 0;
+}
+
+static int verify_packs(struct packed_git *p, void *data)
+{
+	struct verify_packs_data *vpd = (struct verify_packs_data *) data;
+	if (verify_pack(p, fsck_obj_buffer, vpd->progress, vpd->count))
+		errors_found |= ERROR_PACK;
+	vpd->count += p->num_objects;
+	return 0;
+}
+
 int cmd_fsck(int argc, const char **argv, const char *prefix)
 {
 	int i, heads;
@@ -657,29 +680,16 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 	}
 
 	if (check_full) {
-		struct packed_git *p;
-		uint32_t total = 0, count = 0;
-		struct progress *progress = NULL;
+		struct verify_packs_data vpd = {0, 0, 0};
 
 		prepare_packed_git();
 
 		if (show_progress) {
-			for (p = packed_git; p; p = p->next) {
-				if (open_pack_index(p))
-					continue;
-				total += p->num_objects;
-			}
-
-			progress = start_progress("Checking objects", total);
-		}
-		for (p = packed_git; p; p = p->next) {
-			/* verify gives error messages itself */
-			if (verify_pack(p, fsck_obj_buffer,
-					progress, count))
-				errors_found |= ERROR_PACK;
-			count += p->num_objects;
+			foreach_packed_git(count_packs, NULL, &vpd);
+			vpd.progress = start_progress("Checking objects", vpd.total);
 		}
-		stop_progress(&progress);
+		foreach_packed_git(verify_packs, NULL, &vpd);
+		stop_progress(&vpd.progress);
 	}
 
 	heads = 0;