survey: add command line opts to select references

By default we will scan all references in "refs/heads/", "refs/tags/"
and "refs/remotes/".

Add command line opts let the use ask for all refs or a subset of them
and to include a detached HEAD.

Signed-off-by: Jeff Hostetler <[email protected]>

Documentation/git-survey.txt

@@ -19,12 +19,46 @@ As repositories grow to "monorepo" size, certain data shapes can cause
 performance problems.  `git-survey` attempts to measure and report on
 known problem areas.
 
+Ref Selection and Reachable Objects
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In this first analysis phase, `git survey` will iterate over the set of
+requested branches, tags, and other refs and treewalk over all of the
+reachable commits, trees, and blobs and generate various statistics.
+
 OPTIONS
 -------
 
 --progress::
 	Show progress.  This is automatically enabled when interactive.
 
+Ref Selection
+~~~~~~~~~~~~~
+
+The following options control the set of refs that `git survey` will examine.
+By default, `git survey` will look at tags, local branches, and remote refs.
+If any of the following options are given, the default set is cleared and
+only refs for the given options are added.
+
+--all-refs::
+	Use all refs.  This includes local branches, tags, remote refs,
+	notes, and stashes.  This option overrides all of the following.
+
+--branches::
+	Add local branches (`refs/heads/`) to the set.
+
+--tags::
+	Add tags (`refs/tags/`) to the set.
+
+--remotes::
+	Add remote branches (`refs/remote/`) to the set.
+
+--detached::
+	Add HEAD to the set.
+
+--other::
+	Add notes (`refs/notes/`) and stashes (`refs/stash/`) to the set.
+
 OUTPUT
 ------
 

builtin/survey.c

@@ -7,19 +7,117 @@ static const char * const survey_usage[] = {
 	NULL,
 };
 
+struct survey_refs_wanted {
+	int want_all_refs; /* special override */
+
+	int want_branches;
+	int want_tags;
+	int want_remotes;
+	int want_detached;
+	int want_other; /* see FILTER_REFS_OTHERS -- refs/notes/, refs/stash/ */
+};
+
+/*
+ * The set of refs that we will search if the user doesn't select
+ * any on the command line.
+ */
+static struct survey_refs_wanted refs_if_unspecified = {
+	.want_all_refs = 0,
+
+	.want_branches = 1,
+	.want_tags = 1,
+	.want_remotes = 1,
+	.want_detached = 0,
+	.want_other = 0,
+};
+
 struct survey_opts {
 	int verbose;
 	int show_progress;
+	struct survey_refs_wanted refs;
 };
 
 static struct survey_opts survey_opts = {
 	.verbose = 0,
 	.show_progress = -1, /* defaults to isatty(2) */
+
+	.refs.want_all_refs = -1,
+
+	.refs.want_branches = -1, /* default these to undefined */
+	.refs.want_tags = -1,
+	.refs.want_remotes = -1,
+	.refs.want_detached = -1,
+	.refs.want_other = -1,
 };
 
+/*
+ * After parsing the command line arguments, figure out which refs we
+ * should scan.
+ *
+ * If ANY were given in positive sense, then we ONLY include them and
+ * do not use the builtin values.
+ */
+static void fixup_refs_wanted(void)
+{
+	struct survey_refs_wanted *rw = &survey_opts.refs;
+
+	/*
+	 * `--all-refs` overrides and enables everything.
+	 */
+	if (rw->want_all_refs == 1) {
+		rw->want_branches = 1;
+		rw->want_tags = 1;
+		rw->want_remotes = 1;
+		rw->want_detached = 1;
+		rw->want_other = 1;
+		return;
+	}
+
+	/*
+	 * If none of the `--<ref-type>` were given, we assume all
+	 * of the builtin unspecified values.
+	 */
+	if (rw->want_branches == -1 &&
+	    rw->want_tags == -1 &&
+	    rw->want_remotes == -1 &&
+	    rw->want_detached == -1 &&
+	    rw->want_other == -1) {
+		*rw = refs_if_unspecified;
+		return;
+	}
+
+	/*
+	 * Since we only allow positive boolean values on the command
+	 * line, we will only have true values where they specified
+	 * a `--<ref-type>`.
+	 *
+	 * So anything that still has an unspecified value should be
+	 * set to false.
+	 */
+	if (rw->want_branches == -1)
+		rw->want_branches = 0;
+	if (rw->want_tags == -1)
+		rw->want_tags = 0;
+	if (rw->want_remotes == -1)
+		rw->want_remotes = 0;
+	if (rw->want_detached == -1)
+		rw->want_detached = 0;
+	if (rw->want_other == -1)
+		rw->want_other = 0;
+}
+
 static struct option survey_options[] = {
 	OPT__VERBOSE(&survey_opts.verbose, N_("verbose output")),
 	OPT_BOOL(0, "progress", &survey_opts.show_progress, N_("show progress")),
+
+	OPT_BOOL_F(0, "all-refs", &survey_opts.refs.want_all_refs, N_("include all refs"),          PARSE_OPT_NONEG),
+
+	OPT_BOOL_F(0, "branches", &survey_opts.refs.want_branches, N_("include branches"),          PARSE_OPT_NONEG),
+	OPT_BOOL_F(0, "tags",     &survey_opts.refs.want_tags,     N_("include tags"),              PARSE_OPT_NONEG),
+	OPT_BOOL_F(0, "remotes",  &survey_opts.refs.want_remotes,  N_("include all remotes refs"),  PARSE_OPT_NONEG),
+	OPT_BOOL_F(0, "detached", &survey_opts.refs.want_detached, N_("include detached HEAD"),     PARSE_OPT_NONEG),
+	OPT_BOOL_F(0, "other",    &survey_opts.refs.want_other,    N_("include notes and stashes"), PARSE_OPT_NONEG),
+
 	OPT_END(),
 };
 
@@ -53,6 +151,7 @@ int cmd_survey(int argc, const char **argv, const char *prefix)
 
 	if (survey_opts.show_progress < 0)
 		survey_opts.show_progress = isatty(2);
+	fixup_refs_wanted();
 
 	return 0;
 }