commit-graph: introduce `ensure_generations_valid()`

Use the just-introduced compute_reachable_generation_numbers_1() to
implement a function which dynamically computes topological levels (or
corrected commit dates) for out-of-graph commits.

This will be useful for the ahead-behind algorithm we are about to
introduce, which needs accurate topological levels on _all_ commits
reachable from the tips in order to avoid over-counting.

Co-authored-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/commit-graph.c b/commit-graph.c
index 63a56483cf6a041a47ed438cc33097c1fc88b408..172e679db1977f64b5bf2253a4a3ec7dc21b9dd8 100644 (file)
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -1604,6 +1604,35 @@ static void compute_generation_numbers(struct write_commit_graph_context *ctx)
        stop_progress(&ctx->progress);
 }
 
+static void set_generation_in_graph_data(struct commit *c, timestamp_t t,
+                                        void *data)
+{
+       commit_graph_data_at(c)->generation = t;
+}
+
+/*
+ * After this method, all commits reachable from those in the given
+ * list will have non-zero, non-infinite generation numbers.
+ */
+void ensure_generations_valid(struct repository *r,
+                             struct commit **commits, size_t nr)
+{
+       int generation_version = get_configured_generation_version(r);
+       struct packed_commit_list list = {
+               .list = commits,
+               .alloc = nr,
+               .nr = nr,
+       };
+       struct compute_generation_info info = {
+               .r = r,
+               .commits = &list,
+               .get_generation = get_generation_from_graph_data,
+               .set_generation = set_generation_in_graph_data,
+       };
+
+       compute_reachable_generation_numbers(&info, generation_version);
+}
+
 static void trace2_bloom_filter_write_statistics(struct write_commit_graph_context *ctx)
 {
        trace2_data_intmax("commit-graph", ctx->r, "filter-computed",

diff --git a/commit-graph.h b/commit-graph.h
index 37faee6b66d59c693dc9ee829dbd5ad61654fe3c..73e182ab2d0cc742e8c4c212327f7fd32e3b2654 100644 (file)
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -190,4 +190,12 @@ struct commit_graph_data {
  */
 timestamp_t commit_graph_generation(const struct commit *);
 uint32_t commit_graph_position(const struct commit *);
+
+/*
+ * After this method, all commits reachable from those in the given
+ * list will have non-zero, non-infinite generation numbers.
+ */
+void ensure_generations_valid(struct repository *r,
+                             struct commit **commits, size_t nr);
+
 #endif