Hi,
this is version 3 of my patch series to more readily detect commits
parsed from the commit graph which are missing in the object database.
Changes compared to v2:
- Rewrote the help text for `GIT_COMMIT_GRAPH_PARANOIA` to be more
accessible.
- Renamed the `object_paranoia` variable to `commit_graph_paranoia`.
- Fixed a typo.
Thanks!
Patrick
Patrick Steinhardt (2):
commit-graph: introduce envvar to disable commit existence checks
commit: detect commits that exist in commit-graph but not in the ODB
Documentation/git.txt | 10 +++++++++
commit-graph.c | 6 +++++-
commit-graph.h | 6 ++++++
commit.c | 16 +++++++++++++-
t/t5318-commit-graph.sh | 48 +++++++++++++++++++++++++++++++++++++++++
5 files changed, 84 insertions(+), 2 deletions(-)
Range-diff against v2:
1: a89c435528 ! 1: c433ec1254 commit-graph: introduce envvar to disable commit existence checks
@@ Documentation/git.txt: for full details.
useful when trying to salvage data from a corrupted repository.
+`GIT_COMMIT_GRAPH_PARANOIA`::
-+ If this Boolean environment variable is set to false, ignore the
-+ case where commits exist in the commit graph but not in the
-+ object database. Normally, Git will check whether commits loaded
-+ from the commit graph exist in the object database to avoid
-+ issues with stale commit graphs, but this check comes with a
-+ performance penalty. The default is `1` (i.e., be paranoid about
-+ stale commits in the commit graph).
++ When loading a commit object from the commit-graph, Git performs an
++ existence check on the object in the object database. This is done to
++ avoid issues with stale commit-graphs that contain references to
++ already-deleted commits, but comes with a performance penalty.
+++
++The default is "true", which enables the aforementioned behavior.
++Setting this to "false" disables the existence check. This can lead to
++a performance improvement at the cost of consistency.
+
`GIT_ALLOW_PROTOCOL`::
If set to a colon-separated list of protocols, behave as if
@@ commit-graph.c: int repo_find_commit_pos_in_graph(struct repository *r, struct c
struct commit *lookup_commit_in_graph(struct repository *repo, const struct object_id *id)
{
-+ static int object_paranoia = -1;
++ static int commit_graph_paranoia = -1;
struct commit *commit;
uint32_t pos;
-+ if (object_paranoia == -1)
-+ object_paranoia = git_env_bool(GIT_COMMIT_GRAPH_PARANOIA, 1);
++ if (commit_graph_paranoia == -1)
++ commit_graph_paranoia = git_env_bool(GIT_COMMIT_GRAPH_PARANOIA, 1);
+
if (!prepare_commit_graph(repo))
return NULL;
if (!search_commit_pos_in_graph(id, repo->objects->commit_graph, &pos))
return NULL;
- if (!has_object(repo, id, 0))
-+ if (object_paranoia && !has_object(repo, id, 0))
++ if (commit_graph_paranoia && !has_object(repo, id, 0))
return NULL;
commit = lookup_commit(repo, id);
2: 0476d48555 ! 2: 8629fd0892 commit: detect commits that exist in commit-graph but not in the ODB
@@ commit.c: int repo_parse_commit_internal(struct repository *r,
return 0;
- if (use_commit_graph && parse_commit_in_graph(r, item))
+ if (use_commit_graph && parse_commit_in_graph(r, item)) {
-+ static int object_paranoia = -1;
++ static int commit_graph_paranoia = -1;
+
-+ if (object_paranoia == -1)
-+ object_paranoia = git_env_bool(GIT_COMMIT_GRAPH_PARANOIA, 1);
++ if (commit_graph_paranoia == -1)
++ commit_graph_paranoia = git_env_bool(GIT_COMMIT_GRAPH_PARANOIA, 1);
+
-+ if (object_paranoia && !has_object(r, &item->object.oid, 0)) {
++ if (commit_graph_paranoia && !has_object(r, &item->object.oid, 0)) {
+ unparse_commit(r, &item->object.oid);
+ return quiet_on_missing ? -1 :
+ error(_("commit %s exists in commit-graph but not in the object database"),
@@ t/t5318-commit-graph.sh: test_expect_success 'stale commit cannot be parsed when
+ test_commit C &&
+ git commit-graph write --reachable &&
+
-+ # Corrupt the repository by deleting the intermittent commit
++ # Corrupt the repository by deleting the intermediate commit
+ # object. Commands should notice that this object is absent and
+ # thus that the repository is corrupt even if the commit graph
+ # exists.
--
2.42.0
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