On Wed, Aug 05, 2020 at 06:25:31PM -0400, Taylor Blau wrote:
> On Wed, Aug 05, 2020 at 03:21:39PM -0700, Junio C Hamano wrote:
> > Taylor Blau <me@xxxxxxxxxxxx> writes:
> >
> > > On Wed, Aug 05, 2020 at 02:01:29PM -0700, Junio C Hamano wrote:
> > >> Taylor Blau <me@xxxxxxxxxxxx> writes:
> > >>
> > >> > @@ -71,6 +72,10 @@ struct commit_graph {
> > >> > const unsigned char *chunk_base_graphs;
> > >> > const unsigned char *chunk_bloom_indexes;
> > >> > const unsigned char *chunk_bloom_data;
> > >> > + const unsigned char *chunk_bloom_large_filters;
> > >> > +
> > >> > + size_t bloom_large_to_alloc;
> > >> > + struct bitmap bloom_large;
> > >>
> > >> Hmph, is the API rich enough to allow users to release the resource
> > >> used by such an embedded bitmap? I ask becuase...
> > >>
> > >> > @@ -2503,6 +2577,7 @@ void free_commit_graph(struct commit_graph *g)
> > >> > }
> > >> > free(g->filename);
> > >> > free(g->bloom_filter_settings);
> > >> > + bitmap_free(g->bloom_large);
> > >> > free(g);
> > >> > }
> > >>
> > >> ... this hunk cannot be possibly correct as-is, and cannot be made
> > >> correct without changing g->bloom_large to a pointer into a heap
> > >> allocated bitmap, because bitmap_free() wants to not just release
> > >> the resource held by the bitmap but the bitmap itself.
> > >
> > > Yuck, that's definitely wrong. Serves me right for sneaking this in
> > > after I had run `git rebase -x 'make -j40 DEVELOPER=1 test'
> > > upstream/master` ;-).
> > >
> > > Below the scissors line should do the trick. It should apply cleanly at
> > > this point in the series, but it'll produce a compilation failure on the
> > > very last patch (fixing it is straightforward and looks like the
> > > following diff):
> > >
> > > diff --git a/bloom.c b/bloom.c
> > > index d0c0fd049d..8d07209c6b 100644
> > > --- a/bloom.c
> > > +++ b/bloom.c
> > > @@ -52,7 +52,7 @@ static int load_bloom_filter_from_graph(struct commit_graph *g,
> > > start_index = 0;
> > >
> > > if ((start_index == end_index) &&
> > > - (g->bloom_large.word_alloc && !bitmap_get(&g->bloom_large, lex_pos))) {
> > > + (g->bloom_large && !bitmap_get(g->bloom_large, lex_pos))) {
> > > /*
> > > * If the filter is zero-length, either (1) the filter has no
> > > * changes, (2) the filter has too many changes, or (3) it
> > >
> > > In either case, this will fix the bad free():
> > >
> > > --- >8 ---
> > >
> > > Subject: [PATCH] fixup! commit-graph: add large-filters bitmap chunk
> > >
> > > Signed-off-by: Taylor Blau <me@xxxxxxxxxxxx>
> > > ---
> > > commit-graph.c | 18 ++++++++++--------
> > > commit-graph.h | 2 +-
> > > 2 files changed, 11 insertions(+), 9 deletions(-)
> > > ...
> > > @@ -2360,6 +2361,7 @@ int write_commit_graph(struct object_directory *odb,
> > > free(ctx->graph_name);
> > > free(ctx->commits.list);
> > > free(ctx->oids.list);
> > > + free(ctx->bloom_large);
> >
> > Is this correct, or shouldn't it be bitmap_free() instead?
>
> Ack, that should be 'bitmap_free()'. Double checking, 'bitmap_free' does
> handle a 'NULL' argument like 'free', so dealing with an old
> commit-graph lacking this chunk will work fine.
>
> Thanks for catching my mistake. I'm off tomorrow, Friday, and Monday,
> so my responses from now on may be intermittent, but I should have some
> time.
I'm back :). Let's squash the following into patch (bearing in mind that
you'll have to drop a '&' in the final patch of this series as a result
of this change):
--- >8 ---
Subject: [PATCH] fixup! commit-graph: add large-filters bitmap chunk
Makes the commit-graph's 'bloom_large' bitmap a pointer so that it can
be managed with the standard bitmap APIs.
Signed-off-by: Taylor Blau <me@xxxxxxxxxxxx>
---
commit-graph.c | 18 ++++++++++--------
commit-graph.h | 2 +-
2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/commit-graph.c b/commit-graph.c
index 1fee49d171..384089be87 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -438,7 +438,10 @@ struct commit_graph *parse_commit_graph(struct repository *r,
graph->bloom_large_to_alloc = get_be64(chunk_lookup + 4)
- chunk_offset - sizeof(uint32_t);
- graph->bloom_large.word_alloc = 0; /* populate when necessary */
+ /*
+ * leave 'bloom_large' uninitialized, and
+ * populate when necessary
+ */
graph->chunk_bloom_large_filters = data + chunk_offset + sizeof(uint32_t);
graph->bloom_filter_settings->max_changed_paths = get_be32(data + chunk_offset);
}
@@ -960,17 +963,15 @@ static int get_bloom_filter_large_in_graph(struct commit_graph *g,
if (!g || !g->bloom_large_to_alloc)
return 0;
- if (!g->bloom_large.word_alloc) {
+ if (!g->bloom_large) {
size_t i;
- g->bloom_large.word_alloc = g->bloom_large_to_alloc;
- g->bloom_large.words = xmalloc(g->bloom_large_to_alloc * sizeof(eword_t));
-
+ g->bloom_large = bitmap_word_alloc(g->bloom_large_to_alloc);
for (i = 0; i < g->bloom_large_to_alloc; i++)
- g->bloom_large.words[i] = get_be64(g->chunk_bloom_large_filters
- + i * sizeof(eword_t));
+ g->bloom_large->words[i] = get_be64(g->chunk_bloom_large_filters
+ + i * sizeof(eword_t));
}
- return bitmap_get(&g->bloom_large, graph_pos - g->num_commits_in_base);
+ return bitmap_get(g->bloom_large, graph_pos - g->num_commits_in_base);
}
struct packed_oid_list {
@@ -2360,6 +2361,7 @@ int write_commit_graph(struct object_directory *odb,
free(ctx->graph_name);
free(ctx->commits.list);
free(ctx->oids.list);
+ bitmap_free(ctx->bloom_large);
if (ctx->commit_graph_filenames_after) {
for (i = 0; i < ctx->num_commit_graphs_after; i++) {
diff --git a/commit-graph.h b/commit-graph.h
index f4fb996dd5..b1ab86a3c8 100644
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -75,7 +75,7 @@ struct commit_graph {
const unsigned char *chunk_bloom_large_filters;
size_t bloom_large_to_alloc;
- struct bitmap bloom_large;
+ struct bitmap *bloom_large;
struct bloom_filter_settings *bloom_filter_settings;
};
--
2.28.0.rc1.13.ge78abce653
