...
-static int git_walken_config(const char *var, const char *value, void *cb)
+static int git_walken_config(const char *var, const char *value,
+ const struct config_context *ctx, void *cb)
{
/*
* For now, we don't have any custom configuration, so fall back to
* the default config.
*/
- return git_default_config(var, value, cb);
+ return git_default_config(var, value, ctx, cb);
}
----
First some setup. Add `grep_config()` to `git_walken_config()`:
----
-static int git_walken_config(const char *var, const char *value, void *cb)
+static int git_walken_config(const char *var, const char *value,
+ const struct config_context *ctx, void *cb)
{
- grep_config(var, value, cb);
- return git_default_config(var, value, cb);
+ grep_config(var, value, ctx, cb);
+ return git_default_config(var, value, ctx, cb);
}
----
We can base our work on an example. `git pack-objects` prepares all kinds of
objects for packing into a bitmap or packfile. The work we are interested in
-resides in `builtins/pack-objects.c:get_object_list()`; examination of that
+resides in `builtin/pack-objects.c:get_object_list()`; examination of that
function shows that the all-object walk is being performed by
`traverse_commit_list()` or `traverse_commit_list_filtered()`. Those two
functions reside in `list-objects.c`; examining the source shows that, despite
} else {
trace_printf(
_("Filtered object walk with filterspec 'tree:1'.\n"));
- CALLOC_ARRAY(rev->filter, 1);
- parse_list_objects_filter(rev->filter, "tree:1");
+
+ parse_list_objects_filter(&rev->filter, "tree:1");
}
traverse_commit_list(rev, walken_show_commit,
walken_show_object, NULL);
=== Counting Omitted Objects
We also have the capability to enumerate all objects which were omitted by a
-filter, like with `git log --filter=<spec> --filter-print-omitted`. Asking
-`traverse_commit_list_filtered()` to populate the `omitted` list means that our
-object walk does not perform any better than an unfiltered object walk; all
-reachable objects are walked in order to populate the list.
+filter, like with `git log --filter=<spec> --filter-print-omitted`. To do this,
+change `traverse_commit_list()` to `traverse_commit_list_filtered()`, which is
+able to populate an `omitted` list. Asking for this list of filtered objects
+may cause performance degradations, however, because in this case, despite
+filtering objects, the possibly much larger set of all reachable objects must
+be processed in order to populate that list.
First, add the `struct oidset` and related items we will use to iterate it:
...
----
-Modify the call to `traverse_commit_list_filtered()` to include your `omitted`
-object:
+Replace the call to `traverse_commit_list()` with
+`traverse_commit_list_filtered()` and pass a pointer to the `omitted` oidset
+defined and initialized above:
----
...
With only that change, run again (but save yourself some scrollback):
----
-$ GIT_TRACE=1 ./bin-wrappers/git walken | head -n 10
+$ GIT_TRACE=1 ./bin-wrappers/git walken 2>&1 | head -n 10
----
Take a look at the top commit with `git show` and the object ID you printed; it
----
$ make
-$ GIT_TRACE=1 ./bin-wrappers git walken | tail -n 10
+$ GIT_TRACE=1 ./bin-wrappers/git walken 2>&1 | tail -n 10
----
The last commit object given should have the same OID as the one we saw at the