Re: [PATCH] strbuf: add and use strbuf_insertstr()

From: "René Scharfe" <l.s.r@web.de>
To: Eric Sunshine <sunshine@sunshineco.com>
Cc: Git Mailing List <git@vger.kernel.org>,
	Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH] strbuf: add and use strbuf_insertstr()
Date: Sun, 9 Feb 2020 11:23:32 +0100	[thread overview]
Message-ID: <5566a63d-f713-7580-6fc1-83286bc8955d@web.de> (raw)
In-Reply-To: <CAPig+cRmzHEQPhTzHrqqS9So63pJqQVGa1kGoWARmGU_0tn0_A@mail.gmail.com>

Am 09.02.20 um 01:53 schrieb Eric Sunshine:
> On Sat, Feb 8, 2020 at 2:57 PM René Scharfe <l.s.r@web.de> wrote:
>> Add a function for inserting a C string into a strbuf.  Use it
>> throughout the source to get rid of magic string length constants and
>> explicit strlen() calls.
>>
>> Like strbuf_addstr(), implement it as an inline function to avoid the
>> implicit strlen() calls to cause runtime overhead.
>>
>> Signed-off-by: René Scharfe <l.s.r@web.de>
>> ---
>> diff --git a/notes-utils.c b/notes-utils.c
>> @@ -52,7 +52,7 @@ void commit_notes(struct repository *r, struct notes_tree *t, const char *msg)
>> -       strbuf_insert(&buf, 0, "notes: ", 7); /* commit message starts at index 7 */
>> +       strbuf_insertstr(&buf, 0, "notes: "); /* commit message starts at index 7 */
>
> Is there a reason to retain the comment which talks about magic number 7?

I didn't understand its usefulness, so I didn't dare touch it.  Looking
deeper, I think it already became obsolete with 13f8b72d8c (Convert
commit_tree() to take strbuf as message, 2011-12-15), which included:

diff --git a/builtin/notes.c b/builtin/notes.c
index f8e437db01..5e32548cdd 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -301,12 +301,12 @@ void commit_notes(struct notes_tree *t, const char *msg)
 		return; /* don't have to commit an unchanged tree */

 	/* Prepare commit message and reflog message */
-	strbuf_addstr(&buf, "notes: "); /* commit message starts at index 7 */
 	strbuf_addstr(&buf, msg);
 	if (buf.buf[buf.len - 1] != '\n')
 		strbuf_addch(&buf, '\n'); /* Make sure msg ends with newline */

-	create_notes_commit(t, NULL, buf.buf + 7, commit_sha1);
+	create_notes_commit(t, NULL, &buf, commit_sha1);
+	strbuf_insert(&buf, 0, "notes: ", 7); /* commit message starts at index 7 */
 	update_ref(buf.buf, t->ref, commit_sha1, NULL, 0, DIE_ON_ERR);

 	strbuf_release(&buf);

René
