On 11/10/2019 17:02, Johannes Schindelin wrote:
> Hi,
>
> On Thu, 10 Oct 2019, Denton Liu wrote:
>
>> On Fri, Oct 11, 2019 at 10:42:20AM +0900, Junio C Hamano wrote:
>>> Denton Liu <liu.denton@xxxxxxxxx> writes:
>>>
>>>> static int calculate_width(const struct strbuf *row)
>>>> {
>>>> int in_termcode = 0;
>>>> int width = 0;
>>>> int i;
>>>>
>>>> for (i = 0; i < row.len; i++) {
>>>> if (row.buf[i] == '\033')
>>>> in_termcode = 1;
>>>>
>>>> if (!in_termcode)
>>>> width++;
>>>> else if (row.buf[i] == 'm')
>>>> in_termcode = 0;
>>>> }
>>>> }
>>>
>>> Not every byte that is outside the escape sequence contributes to
>>> one display columns. You would want to take a look at utf8_width()
>>> for inspiration.
>>>
>>
>> Heh, I guess you're right. Looking right below the definition of
>> utf8_width, I realised we have the utf8_strnwidth function. We should be
>> able to just call
>>
>> utf8_strnwidth(row.buf, row.len, 1);
>
> Correct me if I'm wrong, but don't we want to keep track of the columns
> *only* in the part with the actual line graph, i.e. we're not at all
> interested in the onelines' widths?
>
> If so, I could imagine that a good idea would be to introduce
>
> struct graphbuf {
> struct strbuf buf;
> int width;
> };
>
> and then introduce wrappers for `_addch()` and whatever else is used in
> `graph.c`, these wrappers will increment the width together with the
> `buf.len` field, and one additional helper that adds color sequences to
> that graphbuf that leaves `width` unchanged.
That's exactly what I've spent this afternoon doing, in response to the feedback here. I took into consideration that:
- We don't want a general solution to this problem for everything `strbuf` could be used for; it only needs to address the graph padding problem.
- We only want to count printing characters, not color formatting sequences.
- We only need to consider the width of a small set of characters: { | / \ _ - . * }. We don't need to worry about Unicode, and the simple character counting in graph.c was working fine.
- Attempting to count the characters in a `strbuf` after the fact is problematic, because sometimes the line prefix (`diff_options.line_prefix`) is included when `graph_pad_horizontally()` is called, and sometimes the prefix has already been sent to stdout and is not included in the `strbuf`. We need to know how many printing characters were added only during `graph_next_line()`.
To this end I've prepared a different implementation that introduces the indirection described above, and does not modify `strbuf`:
diff --git a/graph.c b/graph.c
index f53135485f..24bf1f4fe1 100644
--- a/graph.c
+++ b/graph.c
@@ -112,14 +112,38 @@ static const char *column_get_color_code(unsigned short color)
return column_colors[color];
}
-static void strbuf_write_column(struct strbuf *sb, const struct column *c,
- char col_char)
+struct graph_strbuf {
+ struct strbuf *buf;
+ size_t width;
+};
+
+static inline void graph_strbuf_addch(struct graph_strbuf *sb, int c)
+{
+ strbuf_addch(sb->buf, c);
+ sb->width++;
+}
+
+void graph_strbuf_addchars(struct graph_strbuf *sb, int c, size_t n)
+{
+ strbuf_addchars(sb->buf, c, n);
+ sb->width += n;
+}
+
+static inline void graph_strbuf_addstr(struct graph_strbuf *sb, const char *s)
+{
+ strbuf_addstr(sb->buf, s);
+ sb->width += strlen(s);
+}
+
+static void graph_strbuf_write_column(struct graph_strbuf *sb, const struct column *c,
+ char col_char)
{
if (c->color < column_colors_max)
- strbuf_addstr(sb, column_get_color_code(c->color));
- strbuf_addch(sb, col_char);
+ strbuf_addstr(sb->buf, column_get_color_code(c->color));
+ strbuf_addch(sb->buf, col_char);
+ sb->width++;
if (c->color < column_colors_max)
- strbuf_addstr(sb, column_get_color_code(column_colors_max));
+ strbuf_addstr(sb->buf, column_get_color_code(column_colors_max));
}
struct git_graph {
@@ -686,8 +710,7 @@ static int graph_is_mapping_correct(struct git_graph *graph)
return 1;
}
-static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb,
- int chars_written)
+static void graph_pad_horizontally(struct git_graph *graph, struct graph_strbuf *sb)
{
/*
* Add additional spaces to the end of the strbuf, so that all
@@ -696,12 +719,12 @@ static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb,
* This way, fields printed to the right of the graph will remain
* aligned for the entire commit.
*/
- if (chars_written < graph->width)
- strbuf_addchars(sb, ' ', graph->width - chars_written);
+ if (sb->width < graph->width)
+ strbuf_addchars(sb->buf, ' ', graph->width - sb->width);
}
static void graph_output_padding_line(struct git_graph *graph,
- struct strbuf *sb)
+ struct graph_strbuf *sb)
{
int i;
@@ -719,11 +742,11 @@ static void graph_output_padding_line(struct git_graph *graph,
* Output a padding row, that leaves all branch lines unchanged
*/
for (i = 0; i < graph->num_new_columns; i++) {
- strbuf_write_column(sb, &graph->new_columns[i], '|');
- strbuf_addch(sb, ' ');
+ graph_strbuf_write_column(sb, &graph->new_columns[i], '|');
+ graph_strbuf_addch(sb, ' ');
}
- graph_pad_horizontally(graph, sb, graph->num_new_columns * 2);
+ graph_pad_horizontally(graph, sb);
}
@@ -733,14 +756,14 @@ int graph_width(struct git_graph *graph)
}
-static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
+static void graph_output_skip_line(struct git_graph *graph, struct graph_strbuf *sb)
{
/*
* Output an ellipsis to indicate that a portion
* of the graph is missing.
*/
- strbuf_addstr(sb, "...");
- graph_pad_horizontally(graph, sb, 3);
+ graph_strbuf_addstr(sb, "...");
+ graph_pad_horizontally(graph, sb);
if (graph->num_parents >= 3 &&
graph->commit_index < (graph->num_columns - 1))
@@ -750,11 +773,10 @@ static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
}
static void graph_output_pre_commit_line(struct git_graph *graph,
- struct strbuf *sb)
+ struct graph_strbuf *sb)
{
int num_expansion_rows;
int i, seen_this;
- int chars_written;
/*
* This function formats a row that increases the space around a commit
@@ -777,14 +799,12 @@ static void graph_output_pre_commit_line(struct git_graph *graph,
* Output the row
*/
seen_this = 0;
- chars_written = 0;
for (i = 0; i < graph->num_columns; i++) {
struct column *col = &graph->columns[i];
if (col->commit == graph->commit) {
seen_this = 1;
- strbuf_write_column(sb, col, '|');
- strbuf_addchars(sb, ' ', graph->expansion_row);
- chars_written += 1 + graph->expansion_row;
+ graph_strbuf_write_column(sb, col, '|');
+ graph_strbuf_addchars(sb, ' ', graph->expansion_row);
} else if (seen_this && (graph->expansion_row == 0)) {
/*
* This is the first line of the pre-commit output.
@@ -797,22 +817,18 @@ static void graph_output_pre_commit_line(struct git_graph *graph,
*/
if (graph->prev_state == GRAPH_POST_MERGE &&
graph->prev_commit_index < i)
- strbuf_write_column(sb, col, '\\');
+ graph_strbuf_write_column(sb, col, '\\');
else
- strbuf_write_column(sb, col, '|');
- chars_written++;
+ graph_strbuf_write_column(sb, col, '|');
} else if (seen_this && (graph->expansion_row > 0)) {
- strbuf_write_column(sb, col, '\\');
- chars_written++;
+ graph_strbuf_write_column(sb, col, '\\');
} else {
- strbuf_write_column(sb, col, '|');
- chars_written++;
+ graph_strbuf_write_column(sb, col, '|');
}
- strbuf_addch(sb, ' ');
- chars_written++;
+ graph_strbuf_addch(sb, ' ');
}
- graph_pad_horizontally(graph, sb, chars_written);
+ graph_pad_horizontally(graph, sb);
/*
* Increment graph->expansion_row,
@@ -823,7 +839,7 @@ static void graph_output_pre_commit_line(struct git_graph *graph,
graph_update_state(graph, GRAPH_COMMIT);
}
-static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
+static void graph_output_commit_char(struct git_graph *graph, struct graph_strbuf *sb)
{
/*
* For boundary commits, print 'o'
@@ -831,22 +847,20 @@ static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
*/
if (graph->commit->object.flags & BOUNDARY) {
assert(graph->revs->boundary);
- strbuf_addch(sb, 'o');
+ graph_strbuf_addch(sb, 'o');
return;
}
/*
* get_revision_mark() handles all other cases without assert()
*/
- strbuf_addstr(sb, get_revision_mark(graph->revs, graph->commit));
+ graph_strbuf_addstr(sb, get_revision_mark(graph->revs, graph->commit));
}
/*
- * Draw the horizontal dashes of an octopus merge and return the number of
- * characters written.
+ * Draw the horizontal dashes of an octopus merge.
*/
-static int graph_draw_octopus_merge(struct git_graph *graph,
- struct strbuf *sb)
+static void graph_draw_octopus_merge(struct git_graph *graph, struct graph_strbuf *sb)
{
/*
* Here dashless_parents represents the number of parents which don't
@@ -886,17 +900,16 @@ static int graph_draw_octopus_merge(struct git_graph *graph,
int i;
for (i = 0; i < dashful_parents; i++) {
- strbuf_write_column(sb, &graph->new_columns[i+first_col], '-');
- strbuf_write_column(sb, &graph->new_columns[i+first_col],
- i == dashful_parents-1 ? '.' : '-');
+ graph_strbuf_write_column(sb, &graph->new_columns[i+first_col], '-');
+ graph_strbuf_write_column(sb, &graph->new_columns[i+first_col],
+ i == dashful_parents-1 ? '.' : '-');
}
- return 2 * dashful_parents;
}
-static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
+static void graph_output_commit_line(struct git_graph *graph, struct graph_strbuf *sb)
{
int seen_this = 0;
- int i, chars_written;
+ int i;
/*
* Output the row containing this commit
@@ -906,7 +919,6 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
* children that we have already processed.)
*/
seen_this = 0;
- chars_written = 0;
for (i = 0; i <= graph->num_columns; i++) {
struct column *col = &graph->columns[i];
struct commit *col_commit;
@@ -921,14 +933,11 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
if (col_commit == graph->commit) {
seen_this = 1;
graph_output_commit_char(graph, sb);
- chars_written++;
if (graph->num_parents > 2)
- chars_written += graph_draw_octopus_merge(graph,
- sb);
+ graph_draw_octopus_merge(graph, sb);
} else if (seen_this && (graph->num_parents > 2)) {
- strbuf_write_column(sb, col, '\\');
- chars_written++;
+ graph_strbuf_write_column(sb, col, '\\');
} else if (seen_this && (graph->num_parents == 2)) {
/*
* This is a 2-way merge commit.
@@ -945,19 +954,16 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
*/
if (graph->prev_state == GRAPH_POST_MERGE &&
graph->prev_commit_index < i)
- strbuf_write_column(sb, col, '\\');
+ graph_strbuf_write_column(sb, col, '\\');
else
- strbuf_write_column(sb, col, '|');
- chars_written++;
+ graph_strbuf_write_column(sb, col, '|');
} else {
- strbuf_write_column(sb, col, '|');
- chars_written++;
+ graph_strbuf_write_column(sb, col, '|');
}
- strbuf_addch(sb, ' ');
- chars_written++;
+ graph_strbuf_addch(sb, ' ');
}
- graph_pad_horizontally(graph, sb, chars_written);
+ graph_pad_horizontally(graph, sb);
/*
* Update graph->state
@@ -981,15 +987,14 @@ static struct column *find_new_column_by_commit(struct git_graph *graph,
return NULL;
}
-static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
+static void graph_output_post_merge_line(struct git_graph *graph, struct graph_strbuf *sb)
{
int seen_this = 0;
- int i, j, chars_written;
+ int i, j;
/*
* Output the post-merge row
*/
- chars_written = 0;
for (i = 0; i <= graph->num_columns; i++) {
struct column *col = &graph->columns[i];
struct commit *col_commit;
@@ -1016,29 +1021,25 @@ static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf
par_column = find_new_column_by_commit(graph, parents->item);
assert(par_column);
- strbuf_write_column(sb, par_column, '|');
- chars_written++;
+ graph_strbuf_write_column(sb, par_column, '|');
for (j = 0; j < graph->num_parents - 1; j++) {
parents = next_interesting_parent(graph, parents);
assert(parents);
par_column = find_new_column_by_commit(graph, parents->item);
assert(par_column);
- strbuf_write_column(sb, par_column, '\\');
- strbuf_addch(sb, ' ');
+ graph_strbuf_write_column(sb, par_column, '\\');
+ graph_strbuf_addch(sb, ' ');
}
- chars_written += j * 2;
} else if (seen_this) {
- strbuf_write_column(sb, col, '\\');
- strbuf_addch(sb, ' ');
- chars_written += 2;
+ graph_strbuf_write_column(sb, col, '\\');
+ graph_strbuf_addch(sb, ' ');
} else {
- strbuf_write_column(sb, col, '|');
- strbuf_addch(sb, ' ');
- chars_written += 2;
+ graph_strbuf_write_column(sb, col, '|');
+ graph_strbuf_addch(sb, ' ');
}
}
- graph_pad_horizontally(graph, sb, chars_written);
+ graph_pad_horizontally(graph, sb);
/*
* Update graph->state
@@ -1049,7 +1050,7 @@ static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf
graph_update_state(graph, GRAPH_COLLAPSING);
}
-static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb)
+static void graph_output_collapsing_line(struct git_graph *graph, struct graph_strbuf *sb)
{
int i;
short used_horizontal = 0;
@@ -1159,9 +1160,9 @@ static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf
for (i = 0; i < graph->mapping_size; i++) {
int target = graph->new_mapping[i];
if (target < 0)
- strbuf_addch(sb, ' ');
+ graph_strbuf_addch(sb, ' ');
else if (target * 2 == i)
- strbuf_write_column(sb, &graph->new_columns[target], '|');
+ graph_strbuf_write_column(sb, &graph->new_columns[target], '|');
else if (target == horizontal_edge_target &&
i != horizontal_edge - 1) {
/*
@@ -1172,16 +1173,16 @@ static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf
if (i != (target * 2)+3)
graph->new_mapping[i] = -1;
used_horizontal = 1;
- strbuf_write_column(sb, &graph->new_columns[target], '_');
+ graph_strbuf_write_column(sb, &graph->new_columns[target], '_');
} else {
if (used_horizontal && i < horizontal_edge)
graph->new_mapping[i] = -1;
- strbuf_write_column(sb, &graph->new_columns[target], '/');
+ graph_strbuf_write_column(sb, &graph->new_columns[target], '/');
}
}
- graph_pad_horizontally(graph, sb, graph->mapping_size);
+ graph_pad_horizontally(graph, sb);
/*
* Swap mapping and new_mapping
@@ -1199,24 +1200,26 @@ static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf
int graph_next_line(struct git_graph *graph, struct strbuf *sb)
{
+ struct graph_strbuf gsb = { .buf = sb, .width = 0 };
+
switch (graph->state) {
case GRAPH_PADDING:
- graph_output_padding_line(graph, sb);
+ graph_output_padding_line(graph, &gsb);
return 0;
case GRAPH_SKIP:
- graph_output_skip_line(graph, sb);
+ graph_output_skip_line(graph, &gsb);
return 0;
case GRAPH_PRE_COMMIT:
- graph_output_pre_commit_line(graph, sb);
+ graph_output_pre_commit_line(graph, &gsb);
return 0;
case GRAPH_COMMIT:
- graph_output_commit_line(graph, sb);
+ graph_output_commit_line(graph, &gsb);
return 1;
case GRAPH_POST_MERGE:
- graph_output_post_merge_line(graph, sb);
+ graph_output_post_merge_line(graph, &gsb);
return 0;
case GRAPH_COLLAPSING:
- graph_output_collapsing_line(graph, sb);
+ graph_output_collapsing_line(graph, &gsb);
return 0;
}
@@ -1227,7 +1230,7 @@ int graph_next_line(struct git_graph *graph, struct strbuf *sb)
static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
{
int i;
- int chars_written = 0;
+ struct graph_strbuf gsb = { .buf = sb, .width = 0 };
if (graph->state != GRAPH_COMMIT) {
graph_next_line(graph, sb);
@@ -1244,20 +1247,17 @@ static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
for (i = 0; i < graph->num_columns; i++) {
struct column *col = &graph->columns[i];
- strbuf_write_column(sb, col, '|');
- chars_written++;
+ graph_strbuf_write_column(&gsb, col, '|');
if (col->commit == graph->commit && graph->num_parents > 2) {
int len = (graph->num_parents - 2) * 2;
- strbuf_addchars(sb, ' ', len);
- chars_written += len;
+ graph_strbuf_addchars(&gsb, ' ', len);
} else {
- strbuf_addch(sb, ' ');
- chars_written++;
+ graph_strbuf_addch(&gsb, ' ');
}
}
- graph_pad_horizontally(graph, sb, chars_written);
+ graph_pad_horizontally(graph, &gsb);
/*
* Update graph->prev_state since we have output a padding line
