Re: [PATCH v4 2/5] stash: convert apply to builtin

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 29, 2018, 20:07 UTC
Message-ID: <xmqqlgea63xu.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20180328222129.22192-3-joel@teichroeb.net>

Joel Teichroeb <joel@teichroeb.net> writes:

> +static int get_stash_info(struct stash_info *info, int argc, const char **argv)
> +{

So, this roughly corresponds to parse_flags_and_rev function, it seems.

Show 47 quoted lines

> +	struct strbuf w_commit_rev = STRBUF_INIT;
> +	struct strbuf b_commit_rev = STRBUF_INIT;
> +	struct strbuf w_tree_rev = STRBUF_INIT;
> +	struct strbuf b_tree_rev = STRBUF_INIT;
> +	struct strbuf i_tree_rev = STRBUF_INIT;
> +	struct strbuf u_tree_rev = STRBUF_INIT;
> +	struct strbuf symbolic = STRBUF_INIT;
> +	struct strbuf out = STRBUF_INIT;
> +	int ret;
> +	const char *revision;
> +	const char *commit = NULL;
> +	char *end_of_rev;
> +	info->is_stash_ref = 0;
> +
> +	if (argc > 1) {
> +		int i;
> +		struct strbuf refs_msg = STRBUF_INIT;
> +		for (i = 0; i < argc; ++i)
> +			strbuf_addf(&refs_msg, " '%s'", argv[i]);
> +
> +		fprintf_ln(stderr, _("Too many revisions specified:%s"), refs_msg.buf);
> +		strbuf_release(&refs_msg);
> +
> +		return -1;
> +	}
> +
> +	if (argc == 1)
> +		commit = argv[0];
> +
> +	strbuf_init(&info->revision, 0);
> +	if (commit == NULL) {
> +		if (have_stash()) {
> +			free_stash_info(info);
> +			return error(_("No stash entries found."));
> +		}
> +
> +		strbuf_addf(&info->revision, "%s@{0}", ref_stash);
> +	} else if (strspn(commit, "0123456789") == strlen(commit)) {
> +		strbuf_addf(&info->revision, "%s@{%s}", ref_stash, commit);
> +	} else {
> +		strbuf_addstr(&info->revision, commit);
> +	}
> +
> +	revision = info->revision.buf;
> +	strbuf_addstr(&w_commit_rev, revision);
> +	ret = !get_oid(w_commit_rev.buf, &info->w_commit);
> +	strbuf_release(&w_commit_rev);

Use of strbuf w_commit_rev looks completely pointless here. Am I mistaken to say that the above three lines are equivalent to:

	ret = !get_oid(revision, &info->w_commit);

Show 21 quoted lines

> +
> +	if (!ret) {
> +		error(_("%s is not a valid reference"), revision);
> +		free_stash_info(info);
> +		return -1;
> +	}
> +
> +	strbuf_addf(&b_commit_rev, "%s^1", revision);
> +	strbuf_addf(&w_tree_rev, "%s:", revision);
> +	strbuf_addf(&b_tree_rev, "%s^1:", revision);
> +	strbuf_addf(&i_tree_rev, "%s^2:", revision);
> +
> +	ret = !get_oid(b_commit_rev.buf, &info->b_commit) &&
> +		!get_oid(w_tree_rev.buf, &info->w_tree) &&
> +		!get_oid(b_tree_rev.buf, &info->b_tree) &&
> +		!get_oid(i_tree_rev.buf, &info->i_tree);
> +
> +	strbuf_release(&b_commit_rev);
> +	strbuf_release(&w_tree_rev);
> +	strbuf_release(&b_tree_rev);
> +	strbuf_release(&i_tree_rev);

For the same reason, these strbuf's look pretty much pointless. I wonder if a private helper

	static int grab_oid(struct oid *oid, const char *fmt, const char *rev)
	{
		struct strbuf buf = STRBUF_INIT;
		int ret;

		strbuf_addf(&buf, fmt, rev);
		ret = get_oid(buf, oid);
		strbuf_release(&buf);
		return ret;
	}

would help here? Then you wouldn't be writing something like the above, and instead you'd grab four object names like so:

	if (grab_oid(&info->b_commit, "%s^1", revision) ||
	    grab_oid(&info->w_tree, "%s:", revision) ||
	    grab_oid(&info->b_tree, "%s&1:", revision) ||
	    grab_oid(&info->i_tree, "%s&2:", revision)) {
		... we found an error ...
		return -1;
	}
                
which would be a lot easier to follow, no?

Show 17 quoted lines

> +int cmd_stash__helper(int argc, const char **argv, const char *prefix)
> +{
> +	int result = 0;
> +	pid_t pid = getpid();
> +	const char *index_file;
> +
> +	struct option options[] = {
> +		OPT_END()
> +	};
> +
> +	git_config(git_default_config, NULL);
> +
> +	argc = parse_options(argc, argv, prefix, options, git_stash_helper_usage,
> +		PARSE_OPT_KEEP_UNKNOWN|PARSE_OPT_KEEP_DASHDASH);
> +
> +	index_file = get_index_file();
> +	xsnprintf(stash_index_path, PATH_MAX, "%s.stash.%"PRIuMAX, index_file, (uintmax_t)pid);

Wouldn't it make more sense to get rid of PATH_MAX and hold it in a strbuf instead? I.e.

    static struct strbuf stash_index_path = STRBUF_INIT;
    ...
    strbuf_addf(&stash_index_path, "%s.stash.%" PRIuMAX, index_file, (uintmax_t)pid);

Show 6 quoted lines

> +	cd "$START_DIR"
> +	git stash--helper apply "$@"
> +	res=$?
> +	cd_to_toplevel
> +	return $res
>  }