completion: add a test for __git_remotes() helper function
[git.git] / graph.c
blobc25a09a8fdaf3e90bf7e029c78127146418ab023
1 #include "cache.h"
2 #include "commit.h"
3 #include "color.h"
4 #include "graph.h"
5 #include "diff.h"
6 #include "revision.h"
8 /* Internal API */
11 * Output a padding line in the graph.
12 * This is similar to graph_next_line(). However, it is guaranteed to
13 * never print the current commit line. Instead, if the commit line is
14 * next, it will simply output a line of vertical padding, extending the
15 * branch lines downwards, but leaving them otherwise unchanged.
17 static void graph_padding_line(struct git_graph *graph, struct strbuf *sb);
20 * Print a strbuf to stdout. If the graph is non-NULL, all lines but the
21 * first will be prefixed with the graph output.
23 * If the strbuf ends with a newline, the output will end after this
24 * newline. A new graph line will not be printed after the final newline.
25 * If the strbuf is empty, no output will be printed.
27 * Since the first line will not include the graph output, the caller is
28 * responsible for printing this line's graph (perhaps via
29 * graph_show_commit() or graph_show_oneline()) before calling
30 * graph_show_strbuf().
32 static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb);
35 * TODO:
36 * - Limit the number of columns, similar to the way gitk does.
37 * If we reach more than a specified number of columns, omit
38 * sections of some columns.
41 struct column {
43 * The parent commit of this column.
45 struct commit *commit;
47 * The color to (optionally) print this column in. This is an
48 * index into column_colors.
50 unsigned short color;
53 enum graph_state {
54 GRAPH_PADDING,
55 GRAPH_SKIP,
56 GRAPH_PRE_COMMIT,
57 GRAPH_COMMIT,
58 GRAPH_POST_MERGE,
59 GRAPH_COLLAPSING
62 static const char **column_colors;
63 static unsigned short column_colors_max;
65 void graph_set_column_colors(const char **colors, unsigned short colors_max)
67 column_colors = colors;
68 column_colors_max = colors_max;
71 static const char *column_get_color_code(unsigned short color)
73 return column_colors[color];
76 static void strbuf_write_column(struct strbuf *sb, const struct column *c,
77 char col_char)
79 if (c->color < column_colors_max)
80 strbuf_addstr(sb, column_get_color_code(c->color));
81 strbuf_addch(sb, col_char);
82 if (c->color < column_colors_max)
83 strbuf_addstr(sb, column_get_color_code(column_colors_max));
86 struct git_graph {
88 * The commit currently being processed
90 struct commit *commit;
91 /* The rev-info used for the current traversal */
92 struct rev_info *revs;
94 * The number of interesting parents that this commit has.
96 * Note that this is not the same as the actual number of parents.
97 * This count excludes parents that won't be printed in the graph
98 * output, as determined by graph_is_interesting().
100 int num_parents;
102 * The width of the graph output for this commit.
103 * All rows for this commit are padded to this width, so that
104 * messages printed after the graph output are aligned.
106 int width;
108 * The next expansion row to print
109 * when state is GRAPH_PRE_COMMIT
111 int expansion_row;
113 * The current output state.
114 * This tells us what kind of line graph_next_line() should output.
116 enum graph_state state;
118 * The output state for the previous line of output.
119 * This is primarily used to determine how the first merge line
120 * should appear, based on the last line of the previous commit.
122 enum graph_state prev_state;
124 * The index of the column that refers to this commit.
126 * If none of the incoming columns refer to this commit,
127 * this will be equal to num_columns.
129 int commit_index;
131 * The commit_index for the previously displayed commit.
133 * This is used to determine how the first line of a merge
134 * graph output should appear, based on the last line of the
135 * previous commit.
137 int prev_commit_index;
139 * The maximum number of columns that can be stored in the columns
140 * and new_columns arrays. This is also half the number of entries
141 * that can be stored in the mapping and new_mapping arrays.
143 int column_capacity;
145 * The number of columns (also called "branch lines" in some places)
147 int num_columns;
149 * The number of columns in the new_columns array
151 int num_new_columns;
153 * The number of entries in the mapping array
155 int mapping_size;
157 * The column state before we output the current commit.
159 struct column *columns;
161 * The new column state after we output the current commit.
162 * Only valid when state is GRAPH_COLLAPSING.
164 struct column *new_columns;
166 * An array that tracks the current state of each
167 * character in the output line during state GRAPH_COLLAPSING.
168 * Each entry is -1 if this character is empty, or a non-negative
169 * integer if the character contains a branch line. The value of
170 * the integer indicates the target position for this branch line.
171 * (I.e., this array maps the current column positions to their
172 * desired positions.)
174 * The maximum capacity of this array is always
175 * sizeof(int) * 2 * column_capacity.
177 int *mapping;
179 * A temporary array for computing the next mapping state
180 * while we are outputting a mapping line. This is stored as part
181 * of the git_graph simply so we don't have to allocate a new
182 * temporary array each time we have to output a collapsing line.
184 int *new_mapping;
186 * The current default column color being used. This is
187 * stored as an index into the array column_colors.
189 unsigned short default_column_color;
192 static struct strbuf *diff_output_prefix_callback(struct diff_options *opt, void *data)
194 struct git_graph *graph = data;
195 static struct strbuf msgbuf = STRBUF_INIT;
197 assert(opt);
198 assert(graph);
200 opt->output_prefix_length = graph->width;
201 strbuf_reset(&msgbuf);
202 graph_padding_line(graph, &msgbuf);
203 return &msgbuf;
206 struct git_graph *graph_init(struct rev_info *opt)
208 struct git_graph *graph = xmalloc(sizeof(struct git_graph));
210 if (!column_colors)
211 graph_set_column_colors(column_colors_ansi,
212 column_colors_ansi_max);
214 graph->commit = NULL;
215 graph->revs = opt;
216 graph->num_parents = 0;
217 graph->expansion_row = 0;
218 graph->state = GRAPH_PADDING;
219 graph->prev_state = GRAPH_PADDING;
220 graph->commit_index = 0;
221 graph->prev_commit_index = 0;
222 graph->num_columns = 0;
223 graph->num_new_columns = 0;
224 graph->mapping_size = 0;
226 * Start the column color at the maximum value, since we'll
227 * always increment it for the first commit we output.
228 * This way we start at 0 for the first commit.
230 graph->default_column_color = column_colors_max - 1;
233 * Allocate a reasonably large default number of columns
234 * We'll automatically grow columns later if we need more room.
236 graph->column_capacity = 30;
237 graph->columns = xmalloc(sizeof(struct column) *
238 graph->column_capacity);
239 graph->new_columns = xmalloc(sizeof(struct column) *
240 graph->column_capacity);
241 graph->mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
242 graph->new_mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
245 * The diff output prefix callback, with this we can make
246 * all the diff output to align with the graph lines.
248 opt->diffopt.output_prefix = diff_output_prefix_callback;
249 opt->diffopt.output_prefix_data = graph;
250 opt->diffopt.output_prefix_length = 0;
252 return graph;
255 static void graph_update_state(struct git_graph *graph, enum graph_state s)
257 graph->prev_state = graph->state;
258 graph->state = s;
261 static void graph_ensure_capacity(struct git_graph *graph, int num_columns)
263 if (graph->column_capacity >= num_columns)
264 return;
266 do {
267 graph->column_capacity *= 2;
268 } while (graph->column_capacity < num_columns);
270 REALLOC_ARRAY(graph->columns, graph->column_capacity);
271 REALLOC_ARRAY(graph->new_columns, graph->column_capacity);
272 REALLOC_ARRAY(graph->mapping, graph->column_capacity * 2);
273 REALLOC_ARRAY(graph->new_mapping, graph->column_capacity * 2);
277 * Returns 1 if the commit will be printed in the graph output,
278 * and 0 otherwise.
280 static int graph_is_interesting(struct git_graph *graph, struct commit *commit)
283 * If revs->boundary is set, commits whose children have
284 * been shown are always interesting, even if they have the
285 * UNINTERESTING or TREESAME flags set.
287 if (graph->revs && graph->revs->boundary) {
288 if (commit->object.flags & CHILD_SHOWN)
289 return 1;
293 * Otherwise, use get_commit_action() to see if this commit is
294 * interesting
296 return get_commit_action(graph->revs, commit) == commit_show;
299 static struct commit_list *next_interesting_parent(struct git_graph *graph,
300 struct commit_list *orig)
302 struct commit_list *list;
305 * If revs->first_parent_only is set, only the first
306 * parent is interesting. None of the others are.
308 if (graph->revs->first_parent_only)
309 return NULL;
312 * Return the next interesting commit after orig
314 for (list = orig->next; list; list = list->next) {
315 if (graph_is_interesting(graph, list->item))
316 return list;
319 return NULL;
322 static struct commit_list *first_interesting_parent(struct git_graph *graph)
324 struct commit_list *parents = graph->commit->parents;
327 * If this commit has no parents, ignore it
329 if (!parents)
330 return NULL;
333 * If the first parent is interesting, return it
335 if (graph_is_interesting(graph, parents->item))
336 return parents;
339 * Otherwise, call next_interesting_parent() to get
340 * the next interesting parent
342 return next_interesting_parent(graph, parents);
345 static unsigned short graph_get_current_column_color(const struct git_graph *graph)
347 if (!want_color(graph->revs->diffopt.use_color))
348 return column_colors_max;
349 return graph->default_column_color;
353 * Update the graph's default column color.
355 static void graph_increment_column_color(struct git_graph *graph)
357 graph->default_column_color = (graph->default_column_color + 1) %
358 column_colors_max;
361 static unsigned short graph_find_commit_color(const struct git_graph *graph,
362 const struct commit *commit)
364 int i;
365 for (i = 0; i < graph->num_columns; i++) {
366 if (graph->columns[i].commit == commit)
367 return graph->columns[i].color;
369 return graph_get_current_column_color(graph);
372 static void graph_insert_into_new_columns(struct git_graph *graph,
373 struct commit *commit,
374 int *mapping_index)
376 int i;
379 * If the commit is already in the new_columns list, we don't need to
380 * add it. Just update the mapping correctly.
382 for (i = 0; i < graph->num_new_columns; i++) {
383 if (graph->new_columns[i].commit == commit) {
384 graph->mapping[*mapping_index] = i;
385 *mapping_index += 2;
386 return;
391 * This commit isn't already in new_columns. Add it.
393 graph->new_columns[graph->num_new_columns].commit = commit;
394 graph->new_columns[graph->num_new_columns].color = graph_find_commit_color(graph, commit);
395 graph->mapping[*mapping_index] = graph->num_new_columns;
396 *mapping_index += 2;
397 graph->num_new_columns++;
400 static void graph_update_width(struct git_graph *graph,
401 int is_commit_in_existing_columns)
404 * Compute the width needed to display the graph for this commit.
405 * This is the maximum width needed for any row. All other rows
406 * will be padded to this width.
408 * Compute the number of columns in the widest row:
409 * Count each existing column (graph->num_columns), and each new
410 * column added by this commit.
412 int max_cols = graph->num_columns + graph->num_parents;
415 * Even if the current commit has no parents to be printed, it
416 * still takes up a column for itself.
418 if (graph->num_parents < 1)
419 max_cols++;
422 * We added a column for the current commit as part of
423 * graph->num_parents. If the current commit was already in
424 * graph->columns, then we have double counted it.
426 if (is_commit_in_existing_columns)
427 max_cols--;
430 * Each column takes up 2 spaces
432 graph->width = max_cols * 2;
435 static void graph_update_columns(struct git_graph *graph)
437 struct commit_list *parent;
438 struct column *tmp_columns;
439 int max_new_columns;
440 int mapping_idx;
441 int i, seen_this, is_commit_in_columns;
444 * Swap graph->columns with graph->new_columns
445 * graph->columns contains the state for the previous commit,
446 * and new_columns now contains the state for our commit.
448 * We'll re-use the old columns array as storage to compute the new
449 * columns list for the commit after this one.
451 tmp_columns = graph->columns;
452 graph->columns = graph->new_columns;
453 graph->num_columns = graph->num_new_columns;
455 graph->new_columns = tmp_columns;
456 graph->num_new_columns = 0;
459 * Now update new_columns and mapping with the information for the
460 * commit after this one.
462 * First, make sure we have enough room. At most, there will
463 * be graph->num_columns + graph->num_parents columns for the next
464 * commit.
466 max_new_columns = graph->num_columns + graph->num_parents;
467 graph_ensure_capacity(graph, max_new_columns);
470 * Clear out graph->mapping
472 graph->mapping_size = 2 * max_new_columns;
473 for (i = 0; i < graph->mapping_size; i++)
474 graph->mapping[i] = -1;
477 * Populate graph->new_columns and graph->mapping
479 * Some of the parents of this commit may already be in
480 * graph->columns. If so, graph->new_columns should only contain a
481 * single entry for each such commit. graph->mapping should
482 * contain information about where each current branch line is
483 * supposed to end up after the collapsing is performed.
485 seen_this = 0;
486 mapping_idx = 0;
487 is_commit_in_columns = 1;
488 for (i = 0; i <= graph->num_columns; i++) {
489 struct commit *col_commit;
490 if (i == graph->num_columns) {
491 if (seen_this)
492 break;
493 is_commit_in_columns = 0;
494 col_commit = graph->commit;
495 } else {
496 col_commit = graph->columns[i].commit;
499 if (col_commit == graph->commit) {
500 int old_mapping_idx = mapping_idx;
501 seen_this = 1;
502 graph->commit_index = i;
503 for (parent = first_interesting_parent(graph);
504 parent;
505 parent = next_interesting_parent(graph, parent)) {
507 * If this is a merge, or the start of a new
508 * childless column, increment the current
509 * color.
511 if (graph->num_parents > 1 ||
512 !is_commit_in_columns) {
513 graph_increment_column_color(graph);
515 graph_insert_into_new_columns(graph,
516 parent->item,
517 &mapping_idx);
520 * We always need to increment mapping_idx by at
521 * least 2, even if it has no interesting parents.
522 * The current commit always takes up at least 2
523 * spaces.
525 if (mapping_idx == old_mapping_idx)
526 mapping_idx += 2;
527 } else {
528 graph_insert_into_new_columns(graph, col_commit,
529 &mapping_idx);
534 * Shrink mapping_size to be the minimum necessary
536 while (graph->mapping_size > 1 &&
537 graph->mapping[graph->mapping_size - 1] < 0)
538 graph->mapping_size--;
541 * Compute graph->width for this commit
543 graph_update_width(graph, is_commit_in_columns);
546 void graph_update(struct git_graph *graph, struct commit *commit)
548 struct commit_list *parent;
551 * Set the new commit
553 graph->commit = commit;
556 * Count how many interesting parents this commit has
558 graph->num_parents = 0;
559 for (parent = first_interesting_parent(graph);
560 parent;
561 parent = next_interesting_parent(graph, parent))
563 graph->num_parents++;
567 * Store the old commit_index in prev_commit_index.
568 * graph_update_columns() will update graph->commit_index for this
569 * commit.
571 graph->prev_commit_index = graph->commit_index;
574 * Call graph_update_columns() to update
575 * columns, new_columns, and mapping.
577 graph_update_columns(graph);
579 graph->expansion_row = 0;
582 * Update graph->state.
583 * Note that we don't call graph_update_state() here, since
584 * we don't want to update graph->prev_state. No line for
585 * graph->state was ever printed.
587 * If the previous commit didn't get to the GRAPH_PADDING state,
588 * it never finished its output. Goto GRAPH_SKIP, to print out
589 * a line to indicate that portion of the graph is missing.
591 * If there are 3 or more parents, we may need to print extra rows
592 * before the commit, to expand the branch lines around it and make
593 * room for it. We need to do this only if there is a branch row
594 * (or more) to the right of this commit.
596 * If there are less than 3 parents, we can immediately print the
597 * commit line.
599 if (graph->state != GRAPH_PADDING)
600 graph->state = GRAPH_SKIP;
601 else if (graph->num_parents >= 3 &&
602 graph->commit_index < (graph->num_columns - 1))
603 graph->state = GRAPH_PRE_COMMIT;
604 else
605 graph->state = GRAPH_COMMIT;
608 static int graph_is_mapping_correct(struct git_graph *graph)
610 int i;
613 * The mapping is up to date if each entry is at its target,
614 * or is 1 greater than its target.
615 * (If it is 1 greater than the target, '/' will be printed, so it
616 * will look correct on the next row.)
618 for (i = 0; i < graph->mapping_size; i++) {
619 int target = graph->mapping[i];
620 if (target < 0)
621 continue;
622 if (target == (i / 2))
623 continue;
624 return 0;
627 return 1;
630 static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb,
631 int chars_written)
634 * Add additional spaces to the end of the strbuf, so that all
635 * lines for a particular commit have the same width.
637 * This way, fields printed to the right of the graph will remain
638 * aligned for the entire commit.
640 int extra;
641 if (chars_written >= graph->width)
642 return;
644 extra = graph->width - chars_written;
645 strbuf_addf(sb, "%*s", (int) extra, "");
648 static void graph_output_padding_line(struct git_graph *graph,
649 struct strbuf *sb)
651 int i;
654 * We could conceivable be called with a NULL commit
655 * if our caller has a bug, and invokes graph_next_line()
656 * immediately after graph_init(), without first calling
657 * graph_update(). Return without outputting anything in this
658 * case.
660 if (!graph->commit)
661 return;
664 * Output a padding row, that leaves all branch lines unchanged
666 for (i = 0; i < graph->num_new_columns; i++) {
667 strbuf_write_column(sb, &graph->new_columns[i], '|');
668 strbuf_addch(sb, ' ');
671 graph_pad_horizontally(graph, sb, graph->num_new_columns * 2);
674 static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
677 * Output an ellipsis to indicate that a portion
678 * of the graph is missing.
680 strbuf_addstr(sb, "...");
681 graph_pad_horizontally(graph, sb, 3);
683 if (graph->num_parents >= 3 &&
684 graph->commit_index < (graph->num_columns - 1))
685 graph_update_state(graph, GRAPH_PRE_COMMIT);
686 else
687 graph_update_state(graph, GRAPH_COMMIT);
690 static void graph_output_pre_commit_line(struct git_graph *graph,
691 struct strbuf *sb)
693 int num_expansion_rows;
694 int i, seen_this;
695 int chars_written;
698 * This function formats a row that increases the space around a commit
699 * with multiple parents, to make room for it. It should only be
700 * called when there are 3 or more parents.
702 * We need 2 extra rows for every parent over 2.
704 assert(graph->num_parents >= 3);
705 num_expansion_rows = (graph->num_parents - 2) * 2;
708 * graph->expansion_row tracks the current expansion row we are on.
709 * It should be in the range [0, num_expansion_rows - 1]
711 assert(0 <= graph->expansion_row &&
712 graph->expansion_row < num_expansion_rows);
715 * Output the row
717 seen_this = 0;
718 chars_written = 0;
719 for (i = 0; i < graph->num_columns; i++) {
720 struct column *col = &graph->columns[i];
721 if (col->commit == graph->commit) {
722 seen_this = 1;
723 strbuf_write_column(sb, col, '|');
724 strbuf_addf(sb, "%*s", graph->expansion_row, "");
725 chars_written += 1 + graph->expansion_row;
726 } else if (seen_this && (graph->expansion_row == 0)) {
728 * This is the first line of the pre-commit output.
729 * If the previous commit was a merge commit and
730 * ended in the GRAPH_POST_MERGE state, all branch
731 * lines after graph->prev_commit_index were
732 * printed as "\" on the previous line. Continue
733 * to print them as "\" on this line. Otherwise,
734 * print the branch lines as "|".
736 if (graph->prev_state == GRAPH_POST_MERGE &&
737 graph->prev_commit_index < i)
738 strbuf_write_column(sb, col, '\\');
739 else
740 strbuf_write_column(sb, col, '|');
741 chars_written++;
742 } else if (seen_this && (graph->expansion_row > 0)) {
743 strbuf_write_column(sb, col, '\\');
744 chars_written++;
745 } else {
746 strbuf_write_column(sb, col, '|');
747 chars_written++;
749 strbuf_addch(sb, ' ');
750 chars_written++;
753 graph_pad_horizontally(graph, sb, chars_written);
756 * Increment graph->expansion_row,
757 * and move to state GRAPH_COMMIT if necessary
759 graph->expansion_row++;
760 if (graph->expansion_row >= num_expansion_rows)
761 graph_update_state(graph, GRAPH_COMMIT);
764 static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
767 * For boundary commits, print 'o'
768 * (We should only see boundary commits when revs->boundary is set.)
770 if (graph->commit->object.flags & BOUNDARY) {
771 assert(graph->revs->boundary);
772 strbuf_addch(sb, 'o');
773 return;
777 * get_revision_mark() handles all other cases without assert()
779 strbuf_addstr(sb, get_revision_mark(graph->revs, graph->commit));
783 * Draw an octopus merge and return the number of characters written.
785 static int graph_draw_octopus_merge(struct git_graph *graph,
786 struct strbuf *sb)
789 * Here dashless_commits represents the number of parents
790 * which don't need to have dashes (because their edges fit
791 * neatly under the commit).
793 const int dashless_commits = 2;
794 int col_num, i;
795 int num_dashes =
796 ((graph->num_parents - dashless_commits) * 2) - 1;
797 for (i = 0; i < num_dashes; i++) {
798 col_num = (i / 2) + dashless_commits + graph->commit_index;
799 strbuf_write_column(sb, &graph->new_columns[col_num], '-');
801 col_num = (i / 2) + dashless_commits + graph->commit_index;
802 strbuf_write_column(sb, &graph->new_columns[col_num], '.');
803 return num_dashes + 1;
806 static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
808 int seen_this = 0;
809 int i, chars_written;
812 * Output the row containing this commit
813 * Iterate up to and including graph->num_columns,
814 * since the current commit may not be in any of the existing
815 * columns. (This happens when the current commit doesn't have any
816 * children that we have already processed.)
818 seen_this = 0;
819 chars_written = 0;
820 for (i = 0; i <= graph->num_columns; i++) {
821 struct column *col = &graph->columns[i];
822 struct commit *col_commit;
823 if (i == graph->num_columns) {
824 if (seen_this)
825 break;
826 col_commit = graph->commit;
827 } else {
828 col_commit = graph->columns[i].commit;
831 if (col_commit == graph->commit) {
832 seen_this = 1;
833 graph_output_commit_char(graph, sb);
834 chars_written++;
836 if (graph->num_parents > 2)
837 chars_written += graph_draw_octopus_merge(graph,
838 sb);
839 } else if (seen_this && (graph->num_parents > 2)) {
840 strbuf_write_column(sb, col, '\\');
841 chars_written++;
842 } else if (seen_this && (graph->num_parents == 2)) {
844 * This is a 2-way merge commit.
845 * There is no GRAPH_PRE_COMMIT stage for 2-way
846 * merges, so this is the first line of output
847 * for this commit. Check to see what the previous
848 * line of output was.
850 * If it was GRAPH_POST_MERGE, the branch line
851 * coming into this commit may have been '\',
852 * and not '|' or '/'. If so, output the branch
853 * line as '\' on this line, instead of '|'. This
854 * makes the output look nicer.
856 if (graph->prev_state == GRAPH_POST_MERGE &&
857 graph->prev_commit_index < i)
858 strbuf_write_column(sb, col, '\\');
859 else
860 strbuf_write_column(sb, col, '|');
861 chars_written++;
862 } else {
863 strbuf_write_column(sb, col, '|');
864 chars_written++;
866 strbuf_addch(sb, ' ');
867 chars_written++;
870 graph_pad_horizontally(graph, sb, chars_written);
873 * Update graph->state
875 if (graph->num_parents > 1)
876 graph_update_state(graph, GRAPH_POST_MERGE);
877 else if (graph_is_mapping_correct(graph))
878 graph_update_state(graph, GRAPH_PADDING);
879 else
880 graph_update_state(graph, GRAPH_COLLAPSING);
883 static struct column *find_new_column_by_commit(struct git_graph *graph,
884 struct commit *commit)
886 int i;
887 for (i = 0; i < graph->num_new_columns; i++) {
888 if (graph->new_columns[i].commit == commit)
889 return &graph->new_columns[i];
891 return NULL;
894 static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
896 int seen_this = 0;
897 int i, j, chars_written;
900 * Output the post-merge row
902 chars_written = 0;
903 for (i = 0; i <= graph->num_columns; i++) {
904 struct column *col = &graph->columns[i];
905 struct commit *col_commit;
906 if (i == graph->num_columns) {
907 if (seen_this)
908 break;
909 col_commit = graph->commit;
910 } else {
911 col_commit = col->commit;
914 if (col_commit == graph->commit) {
916 * Since the current commit is a merge find
917 * the columns for the parent commits in
918 * new_columns and use those to format the
919 * edges.
921 struct commit_list *parents = NULL;
922 struct column *par_column;
923 seen_this = 1;
924 parents = first_interesting_parent(graph);
925 assert(parents);
926 par_column = find_new_column_by_commit(graph, parents->item);
927 assert(par_column);
929 strbuf_write_column(sb, par_column, '|');
930 chars_written++;
931 for (j = 0; j < graph->num_parents - 1; j++) {
932 parents = next_interesting_parent(graph, parents);
933 assert(parents);
934 par_column = find_new_column_by_commit(graph, parents->item);
935 assert(par_column);
936 strbuf_write_column(sb, par_column, '\\');
937 strbuf_addch(sb, ' ');
939 chars_written += j * 2;
940 } else if (seen_this) {
941 strbuf_write_column(sb, col, '\\');
942 strbuf_addch(sb, ' ');
943 chars_written += 2;
944 } else {
945 strbuf_write_column(sb, col, '|');
946 strbuf_addch(sb, ' ');
947 chars_written += 2;
951 graph_pad_horizontally(graph, sb, chars_written);
954 * Update graph->state
956 if (graph_is_mapping_correct(graph))
957 graph_update_state(graph, GRAPH_PADDING);
958 else
959 graph_update_state(graph, GRAPH_COLLAPSING);
962 static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb)
964 int i;
965 int *tmp_mapping;
966 short used_horizontal = 0;
967 int horizontal_edge = -1;
968 int horizontal_edge_target = -1;
971 * Clear out the new_mapping array
973 for (i = 0; i < graph->mapping_size; i++)
974 graph->new_mapping[i] = -1;
976 for (i = 0; i < graph->mapping_size; i++) {
977 int target = graph->mapping[i];
978 if (target < 0)
979 continue;
982 * Since update_columns() always inserts the leftmost
983 * column first, each branch's target location should
984 * always be either its current location or to the left of
985 * its current location.
987 * We never have to move branches to the right. This makes
988 * the graph much more legible, since whenever branches
989 * cross, only one is moving directions.
991 assert(target * 2 <= i);
993 if (target * 2 == i) {
995 * This column is already in the
996 * correct place
998 assert(graph->new_mapping[i] == -1);
999 graph->new_mapping[i] = target;
1000 } else if (graph->new_mapping[i - 1] < 0) {
1002 * Nothing is to the left.
1003 * Move to the left by one
1005 graph->new_mapping[i - 1] = target;
1007 * If there isn't already an edge moving horizontally
1008 * select this one.
1010 if (horizontal_edge == -1) {
1011 int j;
1012 horizontal_edge = i;
1013 horizontal_edge_target = target;
1015 * The variable target is the index of the graph
1016 * column, and therefore target*2+3 is the
1017 * actual screen column of the first horizontal
1018 * line.
1020 for (j = (target * 2)+3; j < (i - 2); j += 2)
1021 graph->new_mapping[j] = target;
1023 } else if (graph->new_mapping[i - 1] == target) {
1025 * There is a branch line to our left
1026 * already, and it is our target. We
1027 * combine with this line, since we share
1028 * the same parent commit.
1030 * We don't have to add anything to the
1031 * output or new_mapping, since the
1032 * existing branch line has already taken
1033 * care of it.
1035 } else {
1037 * There is a branch line to our left,
1038 * but it isn't our target. We need to
1039 * cross over it.
1041 * The space just to the left of this
1042 * branch should always be empty.
1044 * The branch to the left of that space
1045 * should be our eventual target.
1047 assert(graph->new_mapping[i - 1] > target);
1048 assert(graph->new_mapping[i - 2] < 0);
1049 assert(graph->new_mapping[i - 3] == target);
1050 graph->new_mapping[i - 2] = target;
1052 * Mark this branch as the horizontal edge to
1053 * prevent any other edges from moving
1054 * horizontally.
1056 if (horizontal_edge == -1)
1057 horizontal_edge = i;
1062 * The new mapping may be 1 smaller than the old mapping
1064 if (graph->new_mapping[graph->mapping_size - 1] < 0)
1065 graph->mapping_size--;
1068 * Output out a line based on the new mapping info
1070 for (i = 0; i < graph->mapping_size; i++) {
1071 int target = graph->new_mapping[i];
1072 if (target < 0)
1073 strbuf_addch(sb, ' ');
1074 else if (target * 2 == i)
1075 strbuf_write_column(sb, &graph->new_columns[target], '|');
1076 else if (target == horizontal_edge_target &&
1077 i != horizontal_edge - 1) {
1079 * Set the mappings for all but the
1080 * first segment to -1 so that they
1081 * won't continue into the next line.
1083 if (i != (target * 2)+3)
1084 graph->new_mapping[i] = -1;
1085 used_horizontal = 1;
1086 strbuf_write_column(sb, &graph->new_columns[target], '_');
1087 } else {
1088 if (used_horizontal && i < horizontal_edge)
1089 graph->new_mapping[i] = -1;
1090 strbuf_write_column(sb, &graph->new_columns[target], '/');
1095 graph_pad_horizontally(graph, sb, graph->mapping_size);
1098 * Swap mapping and new_mapping
1100 tmp_mapping = graph->mapping;
1101 graph->mapping = graph->new_mapping;
1102 graph->new_mapping = tmp_mapping;
1105 * If graph->mapping indicates that all of the branch lines
1106 * are already in the correct positions, we are done.
1107 * Otherwise, we need to collapse some branch lines together.
1109 if (graph_is_mapping_correct(graph))
1110 graph_update_state(graph, GRAPH_PADDING);
1113 int graph_next_line(struct git_graph *graph, struct strbuf *sb)
1115 switch (graph->state) {
1116 case GRAPH_PADDING:
1117 graph_output_padding_line(graph, sb);
1118 return 0;
1119 case GRAPH_SKIP:
1120 graph_output_skip_line(graph, sb);
1121 return 0;
1122 case GRAPH_PRE_COMMIT:
1123 graph_output_pre_commit_line(graph, sb);
1124 return 0;
1125 case GRAPH_COMMIT:
1126 graph_output_commit_line(graph, sb);
1127 return 1;
1128 case GRAPH_POST_MERGE:
1129 graph_output_post_merge_line(graph, sb);
1130 return 0;
1131 case GRAPH_COLLAPSING:
1132 graph_output_collapsing_line(graph, sb);
1133 return 0;
1136 assert(0);
1137 return 0;
1140 static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
1142 int i;
1144 if (graph->state != GRAPH_COMMIT) {
1145 graph_next_line(graph, sb);
1146 return;
1150 * Output the row containing this commit
1151 * Iterate up to and including graph->num_columns,
1152 * since the current commit may not be in any of the existing
1153 * columns. (This happens when the current commit doesn't have any
1154 * children that we have already processed.)
1156 for (i = 0; i < graph->num_columns; i++) {
1157 struct column *col = &graph->columns[i];
1158 strbuf_write_column(sb, col, '|');
1159 if (col->commit == graph->commit && graph->num_parents > 2)
1160 strbuf_addchars(sb, ' ', (graph->num_parents - 2) * 2);
1161 else
1162 strbuf_addch(sb, ' ');
1165 graph_pad_horizontally(graph, sb, graph->num_columns);
1168 * Update graph->prev_state since we have output a padding line
1170 graph->prev_state = GRAPH_PADDING;
1173 int graph_is_commit_finished(struct git_graph const *graph)
1175 return (graph->state == GRAPH_PADDING);
1178 void graph_show_commit(struct git_graph *graph)
1180 struct strbuf msgbuf = STRBUF_INIT;
1181 int shown_commit_line = 0;
1183 if (!graph)
1184 return;
1187 * When showing a diff of a merge against each of its parents, we
1188 * are called once for each parent without graph_update having been
1189 * called. In this case, simply output a single padding line.
1191 if (graph_is_commit_finished(graph)) {
1192 graph_show_padding(graph);
1193 shown_commit_line = 1;
1196 while (!shown_commit_line && !graph_is_commit_finished(graph)) {
1197 shown_commit_line = graph_next_line(graph, &msgbuf);
1198 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1199 if (!shown_commit_line)
1200 putchar('\n');
1201 strbuf_setlen(&msgbuf, 0);
1204 strbuf_release(&msgbuf);
1207 void graph_show_oneline(struct git_graph *graph)
1209 struct strbuf msgbuf = STRBUF_INIT;
1211 if (!graph)
1212 return;
1214 graph_next_line(graph, &msgbuf);
1215 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1216 strbuf_release(&msgbuf);
1219 void graph_show_padding(struct git_graph *graph)
1221 struct strbuf msgbuf = STRBUF_INIT;
1223 if (!graph)
1224 return;
1226 graph_padding_line(graph, &msgbuf);
1227 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1228 strbuf_release(&msgbuf);
1231 int graph_show_remainder(struct git_graph *graph)
1233 struct strbuf msgbuf = STRBUF_INIT;
1234 int shown = 0;
1236 if (!graph)
1237 return 0;
1239 if (graph_is_commit_finished(graph))
1240 return 0;
1242 for (;;) {
1243 graph_next_line(graph, &msgbuf);
1244 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1245 strbuf_setlen(&msgbuf, 0);
1246 shown = 1;
1248 if (!graph_is_commit_finished(graph))
1249 putchar('\n');
1250 else
1251 break;
1253 strbuf_release(&msgbuf);
1255 return shown;
1259 static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb)
1261 char *p;
1263 if (!graph) {
1264 fwrite(sb->buf, sizeof(char), sb->len, stdout);
1265 return;
1269 * Print the strbuf line by line,
1270 * and display the graph info before each line but the first.
1272 p = sb->buf;
1273 while (p) {
1274 size_t len;
1275 char *next_p = strchr(p, '\n');
1276 if (next_p) {
1277 next_p++;
1278 len = next_p - p;
1279 } else {
1280 len = (sb->buf + sb->len) - p;
1282 fwrite(p, sizeof(char), len, stdout);
1283 if (next_p && *next_p != '\0')
1284 graph_show_oneline(graph);
1285 p = next_p;
1289 void graph_show_commit_msg(struct git_graph *graph,
1290 struct strbuf const *sb)
1292 int newline_terminated;
1294 if (!graph) {
1296 * If there's no graph, just print the message buffer.
1298 * The message buffer for CMIT_FMT_ONELINE and
1299 * CMIT_FMT_USERFORMAT are already missing a terminating
1300 * newline. All of the other formats should have it.
1302 fwrite(sb->buf, sizeof(char), sb->len, stdout);
1303 return;
1306 newline_terminated = (sb->len && sb->buf[sb->len - 1] == '\n');
1309 * Show the commit message
1311 graph_show_strbuf(graph, sb);
1314 * If there is more output needed for this commit, show it now
1316 if (!graph_is_commit_finished(graph)) {
1318 * If sb doesn't have a terminating newline, print one now,
1319 * so we can start the remainder of the graph output on a
1320 * new line.
1322 if (!newline_terminated)
1323 putchar('\n');
1325 graph_show_remainder(graph);
1328 * If sb ends with a newline, our output should too.
1330 if (newline_terminated)
1331 putchar('\n');