On Fri, Mar 23, 2012 at 03:12, Zbigniew Jędrzejewski-Szmek
<zbyszek@xxxxxxxxx> wrote:
> On 03/23/2012 06:54 AM, Lucian Poston wrote:
>
>> diff --git a/diff.c b/diff.c
>> index 377ec1e..31ba10c 100644
>> --- a/diff.c
>> +++ b/diff.c
>> @@ -1383,6 +1383,8 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
>> int width, name_width, graph_width, number_width = 4, count;
>> const char *reset, *add_c, *del_c;
>> const char *line_prefix = "";
>> + int line_prefix_length = 0;
>> + int reserved_character_count;
>> int extra_shown = 0;
>> struct strbuf *msg = NULL;
>>
>> @@ -1392,6 +1394,7 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
>> if (options->output_prefix) {
>> msg = options->output_prefix(options, options->output_prefix_data);
>> line_prefix = msg->buf;
>> + line_prefix_length = options->output_prefix_length;
>> }
> Hi,
> line_prefix will only be used once. And options->output_prefix_length will
> be 0 if !options->output_prefix, so line_prefix variable can be eliminated
> and options->output_prefix_length used directly instead.
Rather than adding the line_prefix_length variable, the next patch
will use options->output_prefix_length directly.
>> count = options->stat_count ? options->stat_count : data->nr;
>> @@ -1427,37 +1430,46 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
>> * We have width = stat_width or term_columns() columns total.
>> * We want a maximum of min(max_len, stat_name_width) for the name part.
>> * We want a maximum of min(max_change, stat_graph_width) for the +- part.
>> - * We also need 1 for " " and 4 + decimal_width(max_change)
>> - * for " | NNNN " and one the empty column at the end, altogether
>> + * Each line needs space for the following characters:
>> + * - 1 for the initial " "
>> + * - 4 + decimal_width(max_change) for " | NNNN "
>> + * - 1 for the empty column at the end,
>> + * Altogether, the reserved_character_count totals
>> * 6 + decimal_width(max_change).
>> *
>> - * If there's not enough space, we will use the smaller of
>> - * stat_name_width (if set) and 5/8*width for the filename,
>> - * and the rest for constant elements + graph part, but no more
>> - * than stat_graph_width for the graph part.
>> - * (5/8 gives 50 for filename and 30 for the constant parts + graph
>> - * for the standard terminal size).
>> + * Additionally, there may be a line_prefix, which reduces the available
>> + * width by line_prefix_length.
>> + *
>> + * If there's not enough space, we will use the smaller of stat_name_width
>> + * (if set) and 5/8*width for the filename, and the rest for the graph
>> + * part, but no more than stat_graph_width for the graph part.
>> + * Assuming the line prefix is empty, on a standard 80 column terminal
>> + * this ratio results in 50 characters for the filename and 20 characters
>> + * for the graph (plus the 10 reserved characters).
>> *
>> * In other words: stat_width limits the maximum width, and
>> * stat_name_width fixes the maximum width of the filename,
>> * and is also used to divide available columns if there
>> * aren't enough.
>> */
>> + reserved_character_count = 6 + number_width;
>>
>> if (options->stat_width == -1)
>> width = term_columns();
>> else
>> width = options->stat_width ? options->stat_width : 80;
>>
>> + width -= line_prefix_length;
>> +
>> if (options->stat_graph_width == -1)
>> options->stat_graph_width = diff_stat_graph_width;
>>
>> /*
>> - * Guarantee 3/8*16==6 for the graph part
>> - * and 5/8*16==10 for the filename part
>> + * Guarantees at least 6 characters for the graph part [16 * 3/8]
>> + * and at least 10 for the filename part [16 * 5/8]
>> */
>> - if (width< 16 + 6 + number_width)
>> - width = 16 + 6 + number_width;
>> + if (width< 16 + reserved_character_count)
>> + width = 16 + reserved_character_count;
>>
>> /*
>> * First assign sizes that are wanted, ignoring available width.
>> @@ -1472,16 +1484,36 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
>> /*
>> * Adjust adjustable widths not to exceed maximum width
>> */
>
> In this part below, you add gratuitous braces around single line if-blocks.
> This makes the code (and the diff) longer with no gain.
I prefer gratuitous braces, particularly when conditionals are nested
as they are here. It helps later when maintaining the code if someone
wants to add a debug statement or comment out a line.
I'll remove braces from single line conditionals to keep with the
existing conventions.
>> - if (name_width + number_width + 6 + graph_width> width) {
>> - if (graph_width> width * 3/8 - number_width - 6)
>> - graph_width = width * 3/8 - number_width - 6;
>> + if (reserved_character_count + name_width + graph_width> width) {
>> + /*
>> + * Reduce graph_width to be at most 3/8 of the unreserved space and no
>> + * less than 6, which leaves at least 5/8 for the filename.
>> + */
>> + if (graph_width> width * 3/8 - reserved_character_count) {
>> + graph_width = width * 3/8 - reserved_character_count;
>> + if (graph_width< 6) {
>> + graph_width = 6;
>> + }
>> + }
> This extra test is not necessary. Above, after /* Guarantees at least 6 characters
> for the graph part [16 * 3/8] ... */, this should already by so that
> (width * 3/8 - reserved_character_count) is at least 6.
Ahh, this is because the calculations go haywire when the number of
columns is small. I briefly mentioned it here:
http://thread.gmane.org/gmane.comp.version-control.git/193694/focus=193744
graph_width actually can have a negative value under certain
conditions, and this check compensates for that edge case. My earlier
patches took a less conservative approach and adjusted the
calculations so that the value of graph_width would be at least 6, but
it caused several tests to regress. Since the intention of the
original graph_width calculation was place a lower bound of 6 on its
value, I simply enforce that here without affecting the general cases,
which will remain unmodified in order to prevent test regressions.
>> +
>> + /*
>> + * If the remaining unreserved space will not accomodate the
>> + * filenames, adjust name_width to use all available remaining space.
>> + * Otherwise, assign any extra space to graph_width.
>> + */
>> + if (name_width> width - reserved_character_count - graph_width) {
>> + name_width = width - reserved_character_count - graph_width;
>> + } else {
>> + graph_width = width - reserved_character_count - name_width;
>> + }
>> +
>> + /*
>> + * If stat-graph-width was specified, limit graph_width to its value.
>> + */
>> if (options->stat_graph_width&&
>> - graph_width> options->stat_graph_width)
>> + graph_width> options->stat_graph_width) {
>> graph_width = options->stat_graph_width;
>> - if (name_width> width - number_width - 6 - graph_width)
>> - name_width = width - number_width - 6 - graph_width;
>> - else
>> - graph_width = width - number_width - 6 - name_width;
>> + }
> Here, the order of the two tests
> (1) if (options->stat_graph_width && graph_width > options->stat_graph_width)
> (2) if (name_width > width - number_width - 6 - graph_width)
> is reversed. This is not OK, because this means that
> options->stat_graph_width will be used unconditionally, while
> before it was subject to limiting by total width.
If options->stat_graph_width is specified, it should always limit the
value of graph_width, correct? Since (1) is the last test, it can only
decrease the value of graph_width, which would already be limited by
the total width.
I just noticed that name_width isn't being limited to stat_name_width,
if it is specified. I'll add a check for that.
> The tests:
> After the new tests are added, I see:
>
> ok 53 - format-patch ignores COLUMNS (long filename)
> ok 54 - diff respects COLUMNS (long filename)
> ok 55 - show respects COLUMNS (long filename)
> ok 56 - log respects COLUMNS (long filename)
> ok 57 - show respects 80 COLUMNS (long filename) <=======
> ok 58 - log respects 80 COLUMNS (long filename) <-------
> ok 59 - show respects 80 COLUMNS (long filename) <=======
> ok 60 - log respects 80 COLUMNS (long filename) <-------
>
> So some tests descriptions are duplicated. Also it would be
> nice to test with --graph in more places. I'm attaching a
> replacement patch which adds more tests. It should go *before*
> your series, and your series should tweak the tests to pass,
> showing what changed.
Thanks, I'll add these.
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