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From: Jonathan Tan <jonathantanmy@google.com>
To: Stefan Beller <sbeller@google.com>, git@vger.kernel.org
Cc: peff@peff.net, gitster@pobox.com, mhagger@alum.mit.edu,
	jrnieder@gmail.com, bmwill@google.com
Subject: Re: [PATCH 14/19] diff.c: convert word diffing to use emit_line_*
Date: Mon, 15 May 2017 15:40:56 -0700	[thread overview]
Message-ID: <f49dc4f8-cc83-934f-e582-79efdc613f70@google.com> (raw)
In-Reply-To: <20170514040117.25865-15-sbeller@google.com>

On 05/13/2017 09:01 PM, Stefan Beller wrote:
> 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 covers all code related to diffing words.
>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>  diff.c | 56 ++++++++++++++++++++++++++++----------------------------
>  1 file changed, 28 insertions(+), 28 deletions(-)
>
> diff --git a/diff.c b/diff.c
> index 91dc045a45..07041a35ad 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -886,37 +886,38 @@ struct diff_words_data {
>  	struct diff_words_style *style;
>  };
>
> -static int fn_out_diff_words_write_helper(FILE *fp,
> +static int fn_out_diff_words_write_helper(struct diff_options *o,
>  					  struct diff_words_style_elem *st_el,
>  					  const char *newline,
>  					  size_t count, const char *buf,
>  					  const char *line_prefix)
>  {
> -	int print = 0;
> +	struct strbuf sb = STRBUF_INIT;
>
>  	while (count) {
>  		char *p = memchr(buf, '\n', count);
> -		if (print)
> -			fputs(line_prefix, fp);
> +
>  		if (p != buf) {
> -			if (st_el->color && fputs(st_el->color, fp) < 0)
> -				return -1;
> -			if (fputs(st_el->prefix, fp) < 0 ||
> -			    fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
> -			    fputs(st_el->suffix, fp) < 0)
> -				return -1;
> -			if (st_el->color && *st_el->color
> -			    && fputs(GIT_COLOR_RESET, fp) < 0)
> -				return -1;
> +			if (st_el->color)
> +				strbuf_addstr(&sb, st_el->color);
> +			strbuf_addstr(&sb, st_el->prefix);
> +			strbuf_add(&sb, buf, p ? p - buf : count);
> +			strbuf_addstr(&sb, st_el->suffix);
> +			if (st_el->color && *st_el->color)
> +			    strbuf_addstr(&sb, GIT_COLOR_RESET);
>  		}
>  		if (!p)
> -			return 0;
> -		if (fputs(newline, fp) < 0)
> -			return -1;
> +			goto out;
> +		strbuf_addstr(&sb, newline);
> +		emit_line(o, NULL, NULL, sb.buf, sb.len);

I suspect that this will need to be refactored more thoroughly. Here, 
for example, emit_line (which prints the prefix) is printed nearly 
unconditionally, whereas in the original version, "fputs(line_prefix, 
fp)" is only printed when "print" is true.

> +		strbuf_reset(&sb);
>  		count -= p + 1 - buf;
>  		buf = p + 1;
> -		print = 1;
>  	}
> +out:
> +	if (sb.len)
> +		emit_line(o, NULL, NULL, sb.buf, sb.len);
> +	strbuf_release(&sb);
>  	return 0;
>  }
>
> @@ -994,25 +995,25 @@ static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
>  	} else
>  		plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
>
> -	if (color_words_output_graph_prefix(diff_words)) {
> -		fputs(line_prefix, diff_words->opt->file);
> -	}
> +	if (color_words_output_graph_prefix(diff_words))
> +		emit_line(diff_words->opt, NULL, NULL, "", 0);
> +
>  	if (diff_words->current_plus != plus_begin) {
> -		fn_out_diff_words_write_helper(diff_words->opt->file,
> +		fn_out_diff_words_write_helper(diff_words->opt,
>  				&style->ctx, style->newline,
>  				plus_begin - diff_words->current_plus,
>  				diff_words->current_plus, line_prefix);
>  		if (*(plus_begin - 1) == '\n')
> -			fputs(line_prefix, diff_words->opt->file);
> +			emit_line(diff_words->opt, NULL, NULL, "", 0);
>  	}
>  	if (minus_begin != minus_end) {
> -		fn_out_diff_words_write_helper(diff_words->opt->file,
> +		fn_out_diff_words_write_helper(diff_words->opt,
>  				&style->old, style->newline,
>  				minus_end - minus_begin, minus_begin,
>  				line_prefix);
>  	}
>  	if (plus_begin != plus_end) {
> -		fn_out_diff_words_write_helper(diff_words->opt->file,
> +		fn_out_diff_words_write_helper(diff_words->opt,
>  				&style->new, style->newline,
>  				plus_end - plus_begin, plus_begin,
>  				line_prefix);
> @@ -1109,8 +1110,7 @@ static void diff_words_show(struct diff_words_data *diff_words)
>
>  	/* special case: only removal */
>  	if (!diff_words->plus.text.size) {
> -		fputs(line_prefix, diff_words->opt->file);
> -		fn_out_diff_words_write_helper(diff_words->opt->file,
> +		fn_out_diff_words_write_helper(diff_words->opt,
>  			&style->old, style->newline,
>  			diff_words->minus.text.size,
>  			diff_words->minus.text.ptr, line_prefix);
> @@ -1136,8 +1136,8 @@ static void diff_words_show(struct diff_words_data *diff_words)
>  	if (diff_words->current_plus != diff_words->plus.text.ptr +
>  			diff_words->plus.text.size) {
>  		if (color_words_output_graph_prefix(diff_words))
> -			fputs(line_prefix, diff_words->opt->file);
> -		fn_out_diff_words_write_helper(diff_words->opt->file,
> +			emit_line(diff_words->opt, NULL, NULL, "", 0);
> +		fn_out_diff_words_write_helper(diff_words->opt,
>  			&style->ctx, style->newline,
>  			diff_words->plus.text.ptr + diff_words->plus.text.size
>  			- diff_words->current_plus, diff_words->current_plus,
>

  reply	other threads:[~2017-05-15 22:41 UTC|newest]

Thread overview: 128+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-14  4:00 [RFC PATCH 00/19] Diff machine: highlight moved lines Stefan Beller
2017-05-14  4:00 ` [PATCH 01/19] diff: readability fix Stefan Beller
2017-05-14  4:01 ` [PATCH 02/19] diff: move line ending check into emit_hunk_header Stefan Beller
2017-05-15  6:48   ` Junio C Hamano
2017-05-15 16:13     ` Stefan Beller
2017-05-14  4:01 ` [PATCH 03/19] diff.c: drop 'nofirst' from emit_line_0 Stefan Beller
2017-05-15 18:26   ` Jonathan Tan
2017-05-15 18:33     ` Stefan Beller
2017-05-16 16:05       ` Jonathan Tan
2017-05-15 19:22   ` Brandon Williams
2017-05-15 19:35     ` Stefan Beller
2017-05-15 19:45       ` Brandon Williams
2017-05-14  4:01 ` [PATCH 04/19] diff.c: factor out diff_flush_patch_all_file_pairs Stefan Beller
2017-05-14  4:01 ` [PATCH 05/19] diff.c: emit_line_0 can handle no color setting Stefan Beller
2017-05-15 18:31   ` Jonathan Tan
2017-05-15 22:11     ` Stefan Beller
2017-05-14  4:01 ` [PATCH 06/19] diff: add emit_line_fmt Stefan Beller
2017-05-15 19:31   ` Brandon Williams
2017-05-14  4:01 ` [PATCH 07/19] diff.c: convert fn_out_consume to use emit_line_* Stefan Beller
2017-05-16  1:00   ` Junio C Hamano
2017-05-16  1:05     ` Junio C Hamano
2017-05-16 16:23       ` Stefan Beller
2017-05-14  4:01 ` [PATCH 08/19] diff.c: convert builtin_diff " Stefan Beller
2017-05-15 18:42   ` Jonathan Tan
2017-05-14  4:01 ` [PATCH 09/19] diff.c: convert emit_rewrite_diff " Stefan Beller
2017-05-14  4:01 ` [PATCH 10/19] diff.c: convert emit_rewrite_lines " Stefan Beller
2017-05-15 19:09   ` Jonathan Tan
2017-05-15 19:31     ` Stefan Beller
2017-05-14  4:01 ` [PATCH 11/19] submodule.c: convert show_submodule_summary to use emit_line_fmt Stefan Beller
2017-05-14  4:01 ` [PATCH 12/19] diff.c: convert emit_binary_diff_body to use emit_line_* Stefan Beller
2017-05-14  4:01 ` [PATCH 13/19] diff.c: convert show_stats " Stefan Beller
2017-05-14  4:01 ` [PATCH 14/19] diff.c: convert word diffing " Stefan Beller
2017-05-15 22:40   ` Jonathan Tan [this message]
2017-05-15 23:12     ` Stefan Beller
2017-05-14  4:01 ` [PATCH 15/19] diff.c: convert diff_flush " Stefan Beller
2017-05-15 20:21   ` Jonathan Tan
2017-05-15 22:08     ` Stefan Beller
2017-05-14  4:01 ` [PATCH 16/19] diff.c: convert diff_summary " Stefan Beller
2017-05-14  4:01 ` [PATCH 17/19] diff.c: factor out emit_line_ws for coloring whitespaces Stefan Beller
2017-05-14  4:01 ` [PATCH 18/19] diff: buffer all output if asked to Stefan Beller
2017-05-14  4:06   ` Jeff King
2017-05-14  4:25     ` Stefan Beller
2017-05-16  4:14   ` Jonathan Tan
2017-05-16 16:42     ` Stefan Beller
2017-05-14  4:01 ` [PATCH 19/19] diff.c: color moved lines differently Stefan Beller
2017-05-15 22:42   ` Brandon Williams
2017-05-16  4:34   ` Jonathan Tan
2017-05-16 12:31   ` Jeff King
2017-05-15 12:43 ` [RFC PATCH 00/19] Diff machine: highlight moved lines Junio C Hamano
2017-05-15 16:33   ` Stefan Beller
2017-05-17  2:58 ` [PATCHv2 00/20] " Stefan Beller
2017-05-17  2:58   ` [PATCHv2 01/20] diff: readability fix Stefan Beller
2017-05-17  2:58   ` [PATCHv2 02/20] diff: move line ending check into emit_hunk_header Stefan Beller
2017-05-17  2:58   ` [PATCHv2 03/20] diff.c: factor out diff_flush_patch_all_file_pairs Stefan Beller
2017-05-17  2:58   ` [PATCHv2 04/20] diff.c: teach emit_line_0 to accept sign parameter Stefan Beller
2017-05-17  2:58   ` [PATCHv2 05/20] diff.c: emit_line_0 can handle no color setting Stefan Beller
2017-05-17  2:58   ` [PATCHv2 06/20] diff.c: emit_line_0 takes parameter whether to output line prefix Stefan Beller
2017-05-17  2:58   ` [PATCHv2 07/20] diff.c: inline emit_line_0 into emit_line Stefan Beller
2017-05-17  2:58   ` [PATCHv2 08/20] diff.c: convert fn_out_consume to use emit_line Stefan Beller
2017-05-17  2:58   ` [PATCHv2 09/20] diff.c: convert builtin_diff to use emit_line_* Stefan Beller
2017-05-17  2:58   ` [PATCHv2 10/20] diff.c: convert emit_rewrite_diff " Stefan Beller
2017-05-17  2:58   ` [PATCHv2 11/20] diff.c: convert emit_rewrite_lines " Stefan Beller
2017-05-17  5:03     ` Junio C Hamano
2017-05-17 21:16       ` Stefan Beller
2017-05-18  3:35     ` Junio C Hamano
2017-05-17  2:58   ` [PATCHv2 12/20] submodule.c: convert show_submodule_summary to use emit_line_fmt Stefan Beller
2017-05-17  5:19     ` Junio C Hamano
2017-05-17 21:05       ` Stefan Beller
2017-05-18  3:25         ` Junio C Hamano
2017-05-18 17:12           ` Stefan Beller
2017-05-20  4:50             ` Junio C Hamano
2017-05-20 22:00               ` Stefan Beller
2017-05-17  2:58   ` [PATCHv2 13/20] diff.c: convert emit_binary_diff_body to use emit_line_* Stefan Beller
2017-05-17  2:58   ` [PATCHv2 14/20] diff.c: convert show_stats " Stefan Beller
2017-05-17  2:58   ` [PATCHv2 15/20] diff.c: convert word diffing " Stefan Beller
2017-05-17  2:58   ` [PATCHv2 16/20] diff.c: convert diff_flush " Stefan Beller
2017-05-17  2:58   ` [PATCHv2 17/20] diff.c: convert diff_summary " Stefan Beller
2017-05-17  2:58   ` [PATCHv2 18/20] diff.c: emit_line includes whitespace highlighting Stefan Beller
2017-05-17  2:58   ` [PATCHv2 19/20] diff: buffer all output if asked to Stefan Beller
2017-05-17  2:58   ` [PATCHv2 20/20] diff.c: color moved lines differently Stefan Beller
2017-05-18 19:37   ` [PATCHv3 00/20] Diff machine: highlight moved lines Stefan Beller
2017-05-18 19:37     ` [PATCHv3 01/20] diff: readability fix Stefan Beller
2017-05-18 19:37     ` [PATCHv3 02/20] diff: move line ending check into emit_hunk_header Stefan Beller
2017-05-18 19:37     ` [PATCHv3 03/20] diff.c: factor out diff_flush_patch_all_file_pairs Stefan Beller
2017-05-18 19:37     ` [PATCHv3 04/20] diff.c: teach emit_line_0 to accept sign parameter Stefan Beller
2017-05-18 23:33       ` Jonathan Tan
2017-05-22 23:36         ` Stefan Beller
2017-05-18 19:37     ` [PATCHv3 05/20] diff.c: emit_line_0 can handle no color setting Stefan Beller
2017-05-18 19:37     ` [PATCHv3 06/20] diff.c: emit_line_0 takes parameter whether to output line prefix Stefan Beller
2017-05-18 19:37     ` [PATCHv3 07/20] diff.c: inline emit_line_0 into emit_line Stefan Beller
2017-05-18 19:37     ` [PATCHv3 08/20] diff.c: convert fn_out_consume to use emit_line Stefan Beller
2017-05-18 19:37     ` [PATCHv3 09/20] diff.c: convert builtin_diff to use emit_line_* Stefan Beller
2017-05-18 19:37     ` [PATCHv3 10/20] diff.c: convert emit_rewrite_diff " Stefan Beller
2017-05-18 19:37     ` [PATCHv3 11/20] diff.c: convert emit_rewrite_lines " Stefan Beller
2017-05-18 19:37     ` [PATCHv3 12/20] submodule.c: convert show_submodule_summary to use emit_line_fmt Stefan Beller
2017-05-18 19:37     ` [PATCHv3 13/20] diff.c: convert emit_binary_diff_body to use emit_line_* Stefan Beller
2017-05-18 19:37     ` [PATCHv3 14/20] diff.c: convert show_stats " Stefan Beller
2017-05-18 19:37     ` [PATCHv3 15/20] diff.c: convert word diffing " Stefan Beller
2017-05-18 19:37     ` [PATCHv3 16/20] diff.c: convert diff_flush " Stefan Beller
2017-05-18 19:37     ` [PATCHv3 17/20] diff.c: convert diff_summary " Stefan Beller
2017-05-18 19:37     ` [PATCHv3 18/20] diff.c: emit_line includes whitespace highlighting Stefan Beller
2017-05-18 19:37     ` [PATCHv3 19/20] diff: buffer all output if asked to Stefan Beller
2017-05-18 19:37     ` [PATCHv3 20/20] diff.c: color moved lines differently Stefan Beller
2017-05-19 18:23       ` Jonathan Tan
2017-05-19 18:40         ` Stefan Beller
2017-05-19 19:34           ` Jonathan Tan
2017-05-23  2:40     ` [PATCHv4 00/17] Diff machine: highlight moved lines Stefan Beller
2017-05-23  2:40       ` [PATCHv4 01/17] diff: readability fix Stefan Beller
2017-05-23  2:40       ` [PATCHv4 02/17] diff: move line ending check into emit_hunk_header Stefan Beller
2017-05-23  2:40       ` [PATCHv4 03/17] diff.c: factor out diff_flush_patch_all_file_pairs Stefan Beller
2017-05-23  2:40       ` [PATCHv4 04/17] diff: introduce more flexible emit function Stefan Beller
2017-05-23  2:40       ` [PATCHv4 05/17] diff.c: convert fn_out_consume to use emit_line Stefan Beller
2017-05-23  2:40       ` [PATCHv4 06/17] diff.c: convert builtin_diff to use emit_line_* Stefan Beller
2017-05-23  2:40       ` [PATCHv4 07/17] diff.c: convert emit_rewrite_diff " Stefan Beller
2017-05-23  2:40       ` [PATCHv4 08/17] diff.c: convert emit_rewrite_lines " Stefan Beller
2017-05-23  2:40       ` [PATCHv4 09/17] submodule.c: convert show_submodule_summary to use emit_line_fmt Stefan Beller
2017-05-23  5:59         ` Junio C Hamano
2017-05-23 18:14           ` Stefan Beller
2017-05-23  2:40       ` [PATCHv4 10/17] diff.c: convert emit_binary_diff_body to use emit_line_* Stefan Beller
2017-05-23  2:40       ` [PATCHv4 11/17] diff.c: convert show_stats " Stefan Beller
2017-05-23  2:40       ` [PATCHv4 12/17] diff.c: convert word diffing " Stefan Beller
2017-05-23  2:40       ` [PATCHv4 13/17] diff.c: convert diff_flush " Stefan Beller
2017-05-23  2:40       ` [PATCHv4 14/17] diff.c: convert diff_summary " Stefan Beller
2017-05-23  2:40       ` [PATCHv4 15/17] diff.c: emit_line includes whitespace highlighting Stefan Beller
2017-05-23  2:40       ` [PATCHv4 16/17] diff: buffer all output if asked to Stefan Beller
2017-05-23  2:40       ` [PATCHv4 17/17] diff.c: color moved lines differently Stefan Beller
2017-05-27  1:04       ` [PATCHv4 00/17] Diff machine: highlight moved lines Jacob Keller
2017-05-30 21:38         ` Stefan Beller

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