On Sat, Sep 01, 2018 at 02:53:28PM +0200, Ævar Arnfjörð Bjarmason wrote:
> With this we'll get output like:
>
> $ ~/g/git/git -C ~/g/2015-04-03-1M-git/ --exec-path=$PWD fsck
> Checking object directories: 100% (256/256), done.
> Hashing: 100% (452634108/452634108), done.
> Hashing: 100% (1073741824/1073741824), done.
> Hashing: 100% (1073741824/1073741824), done.
> Hashing: 100% (1008001572/1008001572), done.
> Checking objects: 2% (262144/13064614)
> ^C
>
> All tests pass with this. Isn't it awesome? Except it's of course a
> massive hack, we wouldn't want to just hook into SHA1DC like this.
I still consider that output so-so; the byte counts are big and there's
no indication how many "hashing" lines we're going to see. It's also
broken up in a weird way (it's not one per file; it's one per giant
chunk we fed to sha1).
> The problem comes down to us needing to call git_hash_sha1_update() with
> some really huge input, that function is going to take a *long* time,
> and the only way we're getting incremental progress is:
>
> 1) If we ourselves split the input into N chunks
> 2) If we hack into the SHA1 library itself
>
> This patch does #2, but for this to be acceptable we'd need to do
> something like #1.
I think we could just do the chunking in verify_packfile(), couldn't we?
(And the .idx hash, if we really want to cover that case, but IMHO
that's way less interesting).
Something like this, which chunks it there, uses a per-packfile meter
(though still does not give any clue how many packfiles there are), and
shows a throughput meter.
diff --git a/pack-check.c b/pack-check.c
index d3a57df34f..c94223664f 100644
--- a/pack-check.c
+++ b/pack-check.c
@@ -62,10 +62,25 @@ static int verify_packfile(struct packed_git *p,
uint32_t nr_objects, i;
int err = 0;
struct idx_entry *entries;
+ struct progress *hashing_progress;
+ char *title;
+ off_t total_hashed = 0;
if (!is_pack_valid(p))
return error("packfile %s cannot be accessed", p->pack_name);
+ if (progress) {
+ /* Probably too long... */
+ title = xstrfmt("Hashing %s", p->pack_name);
+
+ /*
+ * I don't think it actually works to have two progresses going
+ * at the same time, because when the first one ends, we'll
+ * cancel the alarm. But hey, this is a hacky proof of concept.
+ */
+ hashing_progress = start_progress(title, 0);
+ }
+
the_hash_algo->init_fn(&ctx);
do {
unsigned long remaining;
@@ -75,9 +90,25 @@ static int verify_packfile(struct packed_git *p,
pack_sig_ofs = p->pack_size - the_hash_algo->rawsz;
if (offset > pack_sig_ofs)
remaining -= (unsigned int)(offset - pack_sig_ofs);
- the_hash_algo->update_fn(&ctx, in, remaining);
+ while (remaining) {
+ int chunk = remaining < 4096 ? remaining : 4096;
+ the_hash_algo->update_fn(&ctx, in, chunk);
+ in += chunk;
+ remaining -= chunk;
+ total_hashed += chunk;
+ /*
+ * The progress code needs tweaking to show throughputs
+ * better for open-ended meters.
+ */
+ display_throughput(hashing_progress, total_hashed);
+ display_progress(hashing_progress, 0);
+ }
} while (offset < pack_sig_ofs);
+
the_hash_algo->final_fn(hash, &ctx);
+ stop_progress(&hashing_progress);
+ free(title);
+
pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
if (hashcmp(hash, pack_sig))
err = error("%s pack checksum mismatch",
