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From:   Junio C Hamano <gitster@pobox.com>
To:     Jeff Hostetler <git@jeffhostetler.com>
Cc:     Jeff Hostetler via GitGitGadget <gitgitgadget@gmail.com>,
        git@vger.kernel.org, Jeff Hostetler <jeffhost@microsoft.com>
Subject: Re: [PATCH 2/9] trace2: convert tr2tls_thread_ctx.thread_name from
 strbuf to char*
References: <pull.1099.git.1640012469.gitgitgadget@gmail.com>
        <3a4fe07e40e967622035844ff10ded1ed71d94fc.1640012469.git.gitgitgadget@gmail.com>
        <xmqqsfumqv62.fsf@gitster.g>
        <ea4eb7f2-863f-2439-d175-cd4e97ad63a6@jeffhostetler.com>
Date:   Wed, 22 Dec 2021 11:57:53 -0800
In-Reply-To: <ea4eb7f2-863f-2439-d175-cd4e97ad63a6@jeffhostetler.com> (Jeff
        Hostetler's message of "Wed, 22 Dec 2021 11:28:23 -0500")
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Jeff Hostetler <git@jeffhostetler.com> writes:

> I'll convert it to a flex-array at the bottom of the CTX structure
> and then defer the truncation to the _perf target (which only does
> that to keep the columns lined up).
>
> That will simplify things considerably.

I am not sure if the complexity of flex-array is worth it.

You have been storing an up-to-24-byte human readable name by
embedding a strbuf that has two size_t plus a pointer (i.e. 24-bytes
even on Windows), and the posted patch changes it to a pointer plus
a on-heap allocation with malloc() overhead.

An embedded fixed-size thread_name[TR2_MAX_THREAD_NAME+1] member
may be the simplest thing to do, I suspect.