Re: [PATCH 02/19] diff: move line ending check into emit_hunk_header
- Date: Mon, 15 May 2017 15:48:24 +0900
- From: Junio C Hamano <gitster@xxxxxxxxx>
- Subject: Re: [PATCH 02/19] diff: move line ending check into emit_hunk_header
Stefan Beller <sbeller@xxxxxxxxxx> writes:
> In a later patch, I want to propose an option to detect&color
> moved lines in a diff, which cannot be done in a one-pass over
> the diff. Instead we need to go over the whole diff twice,
> because we cannot detect the first line of the two corresponding
> lines (+ and -) that got moved.
> So to prepare the diff machinery for two pass algorithms
> (i.e. buffer it all up and then operate on the result),
> move all emissions to places, such that the only emitting
> function is emit_line_0.
> This patch moves code that is conceptually part of
> emit_hunk_header, but was using output in fn_out_consume,
> back to emit_hunk_header.
Makes sort-of sense. If I were selling this patch, I'd remove the
first two paragraph and stress on how completing the line inside
emit_hunk_header() is conceptually cleaner than doing it outside.
emit_hunk_header() function is responsible for assembling a
hunk header and calling emit_line() to send the hunk header
to the output file. Its only caller fn_out_consume() needs
to prepare for a case where the function emits an incomplete
line and add the terminating LF.
Instead make sure emit_hunk_header() to always send a
completed line to emit_line().
or something like that.
Note that I am not saying "buffering the entire diff in-core? why
should we support such a use case?". I am saying that this change
is a clean-up that is justifiable, without having to answer such a
> Meanwhile simplify it by using a function that is designed for it.
> Signed-off-by: Stefan Beller <sbeller@xxxxxxxxxx>
> diff.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
> diff --git a/diff.c b/diff.c
> index 3f5bf8b5a4..c2ed605cd0 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -677,6 +677,8 @@ static void emit_hunk_header(struct emit_callback *ecbdata,
> strbuf_add(&msgbuf, line + len, org_len - len);
> + strbuf_complete_line(&msgbuf);
> emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
> @@ -1315,8 +1317,6 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
> len = sane_truncate_line(ecbdata, line, len);
> find_lno(line, ecbdata);
> emit_hunk_header(ecbdata, line, len);
> - if (line[len-1] != '\n')
> - putc('\n', o->file);