graph API: fix bug in graph_is_interesting()
[git/jnareb-git.git] / graph.c
blob9087f658495200eb671b87711d15c05ad84089ef
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 the next line for a graph.
12 * This formats the next graph line into the specified strbuf. It is not
13 * terminated with a newline.
15 * Returns 1 if the line includes the current commit, and 0 otherwise.
16 * graph_next_line() will return 1 exactly once for each time
17 * graph_update() is called.
19 static int graph_next_line(struct git_graph *graph, struct strbuf *sb);
22 * Output a padding line in the graph.
23 * This is similar to graph_next_line(). However, it is guaranteed to
24 * never print the current commit line. Instead, if the commit line is
25 * next, it will simply output a line of vertical padding, extending the
26 * branch lines downwards, but leaving them otherwise unchanged.
28 static void graph_padding_line(struct git_graph *graph, struct strbuf *sb);
31 * Print a strbuf to stdout. If the graph is non-NULL, all lines but the
32 * first will be prefixed with the graph output.
34 * If the strbuf ends with a newline, the output will end after this
35 * newline. A new graph line will not be printed after the final newline.
36 * If the strbuf is empty, no output will be printed.
38 * Since the first line will not include the graph output, the caller is
39 * responsible for printing this line's graph (perhaps via
40 * graph_show_commit() or graph_show_oneline()) before calling
41 * graph_show_strbuf().
43 static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb);
46 * TODO:
47 * - Limit the number of columns, similar to the way gitk does.
48 * If we reach more than a specified number of columns, omit
49 * sections of some columns.
52 struct column {
54 * The parent commit of this column.
56 struct commit *commit;
58 * The color to (optionally) print this column in. This is an
59 * index into column_colors.
61 unsigned short color;
64 enum graph_state {
65 GRAPH_PADDING,
66 GRAPH_SKIP,
67 GRAPH_PRE_COMMIT,
68 GRAPH_COMMIT,
69 GRAPH_POST_MERGE,
70 GRAPH_COLLAPSING
74 * The list of available column colors.
76 static char column_colors[][COLOR_MAXLEN] = {
77 GIT_COLOR_RED,
78 GIT_COLOR_GREEN,
79 GIT_COLOR_YELLOW,
80 GIT_COLOR_BLUE,
81 GIT_COLOR_MAGENTA,
82 GIT_COLOR_CYAN,
83 GIT_COLOR_BOLD GIT_COLOR_RED,
84 GIT_COLOR_BOLD GIT_COLOR_GREEN,
85 GIT_COLOR_BOLD GIT_COLOR_YELLOW,
86 GIT_COLOR_BOLD GIT_COLOR_BLUE,
87 GIT_COLOR_BOLD GIT_COLOR_MAGENTA,
88 GIT_COLOR_BOLD GIT_COLOR_CYAN,
91 #define COLUMN_COLORS_MAX (ARRAY_SIZE(column_colors))
93 static const char *column_get_color_code(const struct column *c)
95 return column_colors[c->color];
98 static void strbuf_write_column(struct strbuf *sb, const struct column *c,
99 char col_char)
101 if (c->color < COLUMN_COLORS_MAX)
102 strbuf_addstr(sb, column_get_color_code(c));
103 strbuf_addch(sb, col_char);
104 if (c->color < COLUMN_COLORS_MAX)
105 strbuf_addstr(sb, GIT_COLOR_RESET);
108 struct git_graph {
110 * The commit currently being processed
112 struct commit *commit;
113 /* The rev-info used for the current traversal */
114 struct rev_info *revs;
116 * The number of interesting parents that this commit has.
118 * Note that this is not the same as the actual number of parents.
119 * This count excludes parents that won't be printed in the graph
120 * output, as determined by graph_is_interesting().
122 int num_parents;
124 * The width of the graph output for this commit.
125 * All rows for this commit are padded to this width, so that
126 * messages printed after the graph output are aligned.
128 int width;
130 * The next expansion row to print
131 * when state is GRAPH_PRE_COMMIT
133 int expansion_row;
135 * The current output state.
136 * This tells us what kind of line graph_next_line() should output.
138 enum graph_state state;
140 * The output state for the previous line of output.
141 * This is primarily used to determine how the first merge line
142 * should appear, based on the last line of the previous commit.
144 enum graph_state prev_state;
146 * The index of the column that refers to this commit.
148 * If none of the incoming columns refer to this commit,
149 * this will be equal to num_columns.
151 int commit_index;
153 * The commit_index for the previously displayed commit.
155 * This is used to determine how the first line of a merge
156 * graph output should appear, based on the last line of the
157 * previous commit.
159 int prev_commit_index;
161 * The maximum number of columns that can be stored in the columns
162 * and new_columns arrays. This is also half the number of entries
163 * that can be stored in the mapping and new_mapping arrays.
165 int column_capacity;
167 * The number of columns (also called "branch lines" in some places)
169 int num_columns;
171 * The number of columns in the new_columns array
173 int num_new_columns;
175 * The number of entries in the mapping array
177 int mapping_size;
179 * The column state before we output the current commit.
181 struct column *columns;
183 * The new column state after we output the current commit.
184 * Only valid when state is GRAPH_COLLAPSING.
186 struct column *new_columns;
188 * An array that tracks the current state of each
189 * character in the output line during state GRAPH_COLLAPSING.
190 * Each entry is -1 if this character is empty, or a non-negative
191 * integer if the character contains a branch line. The value of
192 * the integer indicates the target position for this branch line.
193 * (I.e., this array maps the current column positions to their
194 * desired positions.)
196 * The maximum capacity of this array is always
197 * sizeof(int) * 2 * column_capacity.
199 int *mapping;
201 * A temporary array for computing the next mapping state
202 * while we are outputting a mapping line. This is stored as part
203 * of the git_graph simply so we don't have to allocate a new
204 * temporary array each time we have to output a collapsing line.
206 int *new_mapping;
208 * The current default column color being used. This is
209 * stored as an index into the array column_colors.
211 unsigned short default_column_color;
214 struct git_graph *graph_init(struct rev_info *opt)
216 struct git_graph *graph = xmalloc(sizeof(struct git_graph));
217 graph->commit = NULL;
218 graph->revs = opt;
219 graph->num_parents = 0;
220 graph->expansion_row = 0;
221 graph->state = GRAPH_PADDING;
222 graph->prev_state = GRAPH_PADDING;
223 graph->commit_index = 0;
224 graph->prev_commit_index = 0;
225 graph->num_columns = 0;
226 graph->num_new_columns = 0;
227 graph->mapping_size = 0;
228 graph->default_column_color = 0;
231 * Allocate a reasonably large default number of columns
232 * We'll automatically grow columns later if we need more room.
234 graph->column_capacity = 30;
235 graph->columns = xmalloc(sizeof(struct column) *
236 graph->column_capacity);
237 graph->new_columns = xmalloc(sizeof(struct column) *
238 graph->column_capacity);
239 graph->mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
240 graph->new_mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
242 return graph;
245 static void graph_update_state(struct git_graph *graph, enum graph_state s)
247 graph->prev_state = graph->state;
248 graph->state = s;
251 static void graph_ensure_capacity(struct git_graph *graph, int num_columns)
253 if (graph->column_capacity >= num_columns)
254 return;
256 do {
257 graph->column_capacity *= 2;
258 } while (graph->column_capacity < num_columns);
260 graph->columns = xrealloc(graph->columns,
261 sizeof(struct column) *
262 graph->column_capacity);
263 graph->new_columns = xrealloc(graph->new_columns,
264 sizeof(struct column) *
265 graph->column_capacity);
266 graph->mapping = xrealloc(graph->mapping,
267 sizeof(int) * 2 * graph->column_capacity);
268 graph->new_mapping = xrealloc(graph->new_mapping,
269 sizeof(int) * 2 * graph->column_capacity);
273 * Returns 1 if the commit will be printed in the graph output,
274 * and 0 otherwise.
276 static int graph_is_interesting(struct git_graph *graph, struct commit *commit)
279 * If revs->boundary is set, commits whose children have
280 * been shown are always interesting, even if they have the
281 * UNINTERESTING or TREESAME flags set.
283 if (graph->revs && graph->revs->boundary) {
284 if (commit->object.flags & CHILD_SHOWN)
285 return 1;
289 * Otherwise, use get_commit_action() to see if this commit is
290 * interesting
292 return get_commit_action(graph->revs, commit) == commit_show;
295 static struct commit_list *next_interesting_parent(struct git_graph *graph,
296 struct commit_list *orig)
298 struct commit_list *list;
301 * If revs->first_parent_only is set, only the first
302 * parent is interesting. None of the others are.
304 if (graph->revs->first_parent_only)
305 return NULL;
308 * Return the next interesting commit after orig
310 for (list = orig->next; list; list = list->next) {
311 if (graph_is_interesting(graph, list->item))
312 return list;
315 return NULL;
318 static struct commit_list *first_interesting_parent(struct git_graph *graph)
320 struct commit_list *parents = graph->commit->parents;
323 * If this commit has no parents, ignore it
325 if (!parents)
326 return NULL;
329 * If the first parent is interesting, return it
331 if (graph_is_interesting(graph, parents->item))
332 return parents;
335 * Otherwise, call next_interesting_parent() to get
336 * the next interesting parent
338 return next_interesting_parent(graph, parents);
341 static unsigned short graph_get_current_column_color(const struct git_graph *graph)
343 if (!DIFF_OPT_TST(&graph->revs->diffopt, COLOR_DIFF))
344 return COLUMN_COLORS_MAX;
345 return graph->default_column_color;
349 * Update the graph's default column color.
351 static void graph_increment_column_color(struct git_graph *graph)
353 graph->default_column_color = (graph->default_column_color + 1) %
354 COLUMN_COLORS_MAX;
357 static unsigned short graph_find_commit_color(const struct git_graph *graph,
358 const struct commit *commit)
360 int i;
361 for (i = 0; i < graph->num_columns; i++) {
362 if (graph->columns[i].commit == commit)
363 return graph->columns[i].color;
365 return graph_get_current_column_color(graph);
368 static void graph_insert_into_new_columns(struct git_graph *graph,
369 struct commit *commit,
370 int *mapping_index)
372 int i;
375 * If the commit is already in the new_columns list, we don't need to
376 * add it. Just update the mapping correctly.
378 for (i = 0; i < graph->num_new_columns; i++) {
379 if (graph->new_columns[i].commit == commit) {
380 graph->mapping[*mapping_index] = i;
381 *mapping_index += 2;
382 return;
387 * This commit isn't already in new_columns. Add it.
389 graph->new_columns[graph->num_new_columns].commit = commit;
390 graph->new_columns[graph->num_new_columns].color = graph_find_commit_color(graph, commit);
391 graph->mapping[*mapping_index] = graph->num_new_columns;
392 *mapping_index += 2;
393 graph->num_new_columns++;
396 static void graph_update_width(struct git_graph *graph,
397 int is_commit_in_existing_columns)
400 * Compute the width needed to display the graph for this commit.
401 * This is the maximum width needed for any row. All other rows
402 * will be padded to this width.
404 * Compute the number of columns in the widest row:
405 * Count each existing column (graph->num_columns), and each new
406 * column added by this commit.
408 int max_cols = graph->num_columns + graph->num_parents;
411 * Even if the current commit has no parents to be printed, it
412 * still takes up a column for itself.
414 if (graph->num_parents < 1)
415 max_cols++;
418 * We added a column for the the current commit as part of
419 * graph->num_parents. If the current commit was already in
420 * graph->columns, then we have double counted it.
422 if (is_commit_in_existing_columns)
423 max_cols--;
426 * Each column takes up 2 spaces
428 graph->width = max_cols * 2;
431 static void graph_update_columns(struct git_graph *graph)
433 struct commit_list *parent;
434 struct column *tmp_columns;
435 int max_new_columns;
436 int mapping_idx;
437 int i, seen_this, is_commit_in_columns;
440 * Swap graph->columns with graph->new_columns
441 * graph->columns contains the state for the previous commit,
442 * and new_columns now contains the state for our commit.
444 * We'll re-use the old columns array as storage to compute the new
445 * columns list for the commit after this one.
447 tmp_columns = graph->columns;
448 graph->columns = graph->new_columns;
449 graph->num_columns = graph->num_new_columns;
451 graph->new_columns = tmp_columns;
452 graph->num_new_columns = 0;
455 * Now update new_columns and mapping with the information for the
456 * commit after this one.
458 * First, make sure we have enough room. At most, there will
459 * be graph->num_columns + graph->num_parents columns for the next
460 * commit.
462 max_new_columns = graph->num_columns + graph->num_parents;
463 graph_ensure_capacity(graph, max_new_columns);
466 * Clear out graph->mapping
468 graph->mapping_size = 2 * max_new_columns;
469 for (i = 0; i < graph->mapping_size; i++)
470 graph->mapping[i] = -1;
473 * Populate graph->new_columns and graph->mapping
475 * Some of the parents of this commit may already be in
476 * graph->columns. If so, graph->new_columns should only contain a
477 * single entry for each such commit. graph->mapping should
478 * contain information about where each current branch line is
479 * supposed to end up after the collapsing is performed.
481 seen_this = 0;
482 mapping_idx = 0;
483 is_commit_in_columns = 1;
484 for (i = 0; i <= graph->num_columns; i++) {
485 struct commit *col_commit;
486 if (i == graph->num_columns) {
487 if (seen_this)
488 break;
489 is_commit_in_columns = 0;
490 col_commit = graph->commit;
491 } else {
492 col_commit = graph->columns[i].commit;
495 if (col_commit == graph->commit) {
496 int old_mapping_idx = mapping_idx;
497 seen_this = 1;
498 graph->commit_index = i;
499 for (parent = first_interesting_parent(graph);
500 parent;
501 parent = next_interesting_parent(graph, parent)) {
503 * If this is a merge increment the current
504 * color.
506 if (graph->num_parents > 1)
507 graph_increment_column_color(graph);
508 graph_insert_into_new_columns(graph,
509 parent->item,
510 &mapping_idx);
513 * We always need to increment mapping_idx by at
514 * least 2, even if it has no interesting parents.
515 * The current commit always takes up at least 2
516 * spaces.
518 if (mapping_idx == old_mapping_idx)
519 mapping_idx += 2;
520 } else {
521 graph_insert_into_new_columns(graph, col_commit,
522 &mapping_idx);
527 * Shrink mapping_size to be the minimum necessary
529 while (graph->mapping_size > 1 &&
530 graph->mapping[graph->mapping_size - 1] < 0)
531 graph->mapping_size--;
534 * Compute graph->width for this commit
536 graph_update_width(graph, is_commit_in_columns);
539 void graph_update(struct git_graph *graph, struct commit *commit)
541 struct commit_list *parent;
544 * Set the new commit
546 graph->commit = commit;
549 * Count how many interesting parents this commit has
551 graph->num_parents = 0;
552 for (parent = first_interesting_parent(graph);
553 parent;
554 parent = next_interesting_parent(graph, parent))
556 graph->num_parents++;
560 * Store the old commit_index in prev_commit_index.
561 * graph_update_columns() will update graph->commit_index for this
562 * commit.
564 graph->prev_commit_index = graph->commit_index;
567 * Call graph_update_columns() to update
568 * columns, new_columns, and mapping.
570 graph_update_columns(graph);
572 graph->expansion_row = 0;
575 * Update graph->state.
576 * Note that we don't call graph_update_state() here, since
577 * we don't want to update graph->prev_state. No line for
578 * graph->state was ever printed.
580 * If the previous commit didn't get to the GRAPH_PADDING state,
581 * it never finished its output. Goto GRAPH_SKIP, to print out
582 * a line to indicate that portion of the graph is missing.
584 * If there are 3 or more parents, we may need to print extra rows
585 * before the commit, to expand the branch lines around it and make
586 * room for it. We need to do this only if there is a branch row
587 * (or more) to the right of this commit.
589 * If there are less than 3 parents, we can immediately print the
590 * commit line.
592 if (graph->state != GRAPH_PADDING)
593 graph->state = GRAPH_SKIP;
594 else if (graph->num_parents >= 3 &&
595 graph->commit_index < (graph->num_columns - 1))
596 graph->state = GRAPH_PRE_COMMIT;
597 else
598 graph->state = GRAPH_COMMIT;
601 static int graph_is_mapping_correct(struct git_graph *graph)
603 int i;
606 * The mapping is up to date if each entry is at its target,
607 * or is 1 greater than its target.
608 * (If it is 1 greater than the target, '/' will be printed, so it
609 * will look correct on the next row.)
611 for (i = 0; i < graph->mapping_size; i++) {
612 int target = graph->mapping[i];
613 if (target < 0)
614 continue;
615 if (target == (i / 2))
616 continue;
617 return 0;
620 return 1;
623 static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb,
624 int chars_written)
627 * Add additional spaces to the end of the strbuf, so that all
628 * lines for a particular commit have the same width.
630 * This way, fields printed to the right of the graph will remain
631 * aligned for the entire commit.
633 int extra;
634 if (chars_written >= graph->width)
635 return;
637 extra = graph->width - chars_written;
638 strbuf_addf(sb, "%*s", (int) extra, "");
641 static void graph_output_padding_line(struct git_graph *graph,
642 struct strbuf *sb)
644 int i;
647 * We could conceivable be called with a NULL commit
648 * if our caller has a bug, and invokes graph_next_line()
649 * immediately after graph_init(), without first calling
650 * graph_update(). Return without outputting anything in this
651 * case.
653 if (!graph->commit)
654 return;
657 * Output a padding row, that leaves all branch lines unchanged
659 for (i = 0; i < graph->num_new_columns; i++) {
660 strbuf_write_column(sb, &graph->new_columns[i], '|');
661 strbuf_addch(sb, ' ');
664 graph_pad_horizontally(graph, sb, graph->num_new_columns * 2);
667 static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
670 * Output an ellipsis to indicate that a portion
671 * of the graph is missing.
673 strbuf_addstr(sb, "...");
674 graph_pad_horizontally(graph, sb, 3);
676 if (graph->num_parents >= 3 &&
677 graph->commit_index < (graph->num_columns - 1))
678 graph_update_state(graph, GRAPH_PRE_COMMIT);
679 else
680 graph_update_state(graph, GRAPH_COMMIT);
683 static void graph_output_pre_commit_line(struct git_graph *graph,
684 struct strbuf *sb)
686 int num_expansion_rows;
687 int i, seen_this;
688 int chars_written;
691 * This function formats a row that increases the space around a commit
692 * with multiple parents, to make room for it. It should only be
693 * called when there are 3 or more parents.
695 * We need 2 extra rows for every parent over 2.
697 assert(graph->num_parents >= 3);
698 num_expansion_rows = (graph->num_parents - 2) * 2;
701 * graph->expansion_row tracks the current expansion row we are on.
702 * It should be in the range [0, num_expansion_rows - 1]
704 assert(0 <= graph->expansion_row &&
705 graph->expansion_row < num_expansion_rows);
708 * Output the row
710 seen_this = 0;
711 chars_written = 0;
712 for (i = 0; i < graph->num_columns; i++) {
713 struct column *col = &graph->columns[i];
714 if (col->commit == graph->commit) {
715 seen_this = 1;
716 strbuf_write_column(sb, col, '|');
717 strbuf_addf(sb, "%*s", graph->expansion_row, "");
718 chars_written += 1 + graph->expansion_row;
719 } else if (seen_this && (graph->expansion_row == 0)) {
721 * This is the first line of the pre-commit output.
722 * If the previous commit was a merge commit and
723 * ended in the GRAPH_POST_MERGE state, all branch
724 * lines after graph->prev_commit_index were
725 * printed as "\" on the previous line. Continue
726 * to print them as "\" on this line. Otherwise,
727 * print the branch lines as "|".
729 if (graph->prev_state == GRAPH_POST_MERGE &&
730 graph->prev_commit_index < i)
731 strbuf_write_column(sb, col, '\\');
732 else
733 strbuf_write_column(sb, col, '|');
734 chars_written++;
735 } else if (seen_this && (graph->expansion_row > 0)) {
736 strbuf_write_column(sb, col, '\\');
737 chars_written++;
738 } else {
739 strbuf_write_column(sb, col, '|');
740 chars_written++;
742 strbuf_addch(sb, ' ');
743 chars_written++;
746 graph_pad_horizontally(graph, sb, chars_written);
749 * Increment graph->expansion_row,
750 * and move to state GRAPH_COMMIT if necessary
752 graph->expansion_row++;
753 if (graph->expansion_row >= num_expansion_rows)
754 graph_update_state(graph, GRAPH_COMMIT);
757 static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
760 * For boundary commits, print 'o'
761 * (We should only see boundary commits when revs->boundary is set.)
763 if (graph->commit->object.flags & BOUNDARY) {
764 assert(graph->revs->boundary);
765 strbuf_addch(sb, 'o');
766 return;
770 * If revs->left_right is set, print '<' for commits that
771 * come from the left side, and '>' for commits from the right
772 * side.
774 if (graph->revs && graph->revs->left_right) {
775 if (graph->commit->object.flags & SYMMETRIC_LEFT)
776 strbuf_addch(sb, '<');
777 else
778 strbuf_addch(sb, '>');
779 return;
783 * Print '*' in all other cases
785 strbuf_addch(sb, '*');
789 * Draw an octopus merge and return the number of characters written.
791 static int graph_draw_octopus_merge(struct git_graph *graph,
792 struct strbuf *sb)
795 * Here dashless_commits represents the number of parents
796 * which don't need to have dashes (because their edges fit
797 * neatly under the commit).
799 const int dashless_commits = 2;
800 int col_num, i;
801 int num_dashes =
802 ((graph->num_parents - dashless_commits) * 2) - 1;
803 for (i = 0; i < num_dashes; i++) {
804 col_num = (i / 2) + dashless_commits;
805 strbuf_write_column(sb, &graph->new_columns[col_num], '-');
807 col_num = (i / 2) + dashless_commits;
808 strbuf_write_column(sb, &graph->new_columns[col_num], '.');
809 return num_dashes + 1;
812 static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
814 int seen_this = 0;
815 int i, chars_written;
818 * Output the row containing this commit
819 * Iterate up to and including graph->num_columns,
820 * since the current commit may not be in any of the existing
821 * columns. (This happens when the current commit doesn't have any
822 * children that we have already processed.)
824 seen_this = 0;
825 chars_written = 0;
826 for (i = 0; i <= graph->num_columns; i++) {
827 struct column *col = &graph->columns[i];
828 struct commit *col_commit;
829 if (i == graph->num_columns) {
830 if (seen_this)
831 break;
832 col_commit = graph->commit;
833 } else {
834 col_commit = graph->columns[i].commit;
837 if (col_commit == graph->commit) {
838 seen_this = 1;
839 graph_output_commit_char(graph, sb);
840 chars_written++;
842 if (graph->num_parents > 2)
843 chars_written += graph_draw_octopus_merge(graph,
844 sb);
845 } else if (seen_this && (graph->num_parents > 2)) {
846 strbuf_write_column(sb, col, '\\');
847 chars_written++;
848 } else if (seen_this && (graph->num_parents == 2)) {
850 * This is a 2-way merge commit.
851 * There is no GRAPH_PRE_COMMIT stage for 2-way
852 * merges, so this is the first line of output
853 * for this commit. Check to see what the previous
854 * line of output was.
856 * If it was GRAPH_POST_MERGE, the branch line
857 * coming into this commit may have been '\',
858 * and not '|' or '/'. If so, output the branch
859 * line as '\' on this line, instead of '|'. This
860 * makes the output look nicer.
862 if (graph->prev_state == GRAPH_POST_MERGE &&
863 graph->prev_commit_index < i)
864 strbuf_write_column(sb, col, '\\');
865 else
866 strbuf_write_column(sb, col, '|');
867 chars_written++;
868 } else {
869 strbuf_write_column(sb, col, '|');
870 chars_written++;
872 strbuf_addch(sb, ' ');
873 chars_written++;
876 graph_pad_horizontally(graph, sb, chars_written);
879 * Update graph->state
881 if (graph->num_parents > 1)
882 graph_update_state(graph, GRAPH_POST_MERGE);
883 else if (graph_is_mapping_correct(graph))
884 graph_update_state(graph, GRAPH_PADDING);
885 else
886 graph_update_state(graph, GRAPH_COLLAPSING);
889 static struct column *find_new_column_by_commit(struct git_graph *graph,
890 struct commit *commit)
892 int i;
893 for (i = 0; i < graph->num_new_columns; i++) {
894 if (graph->new_columns[i].commit == commit)
895 return &graph->new_columns[i];
897 return NULL;
900 static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
902 int seen_this = 0;
903 int i, j, chars_written;
906 * Output the post-merge row
908 chars_written = 0;
909 for (i = 0; i <= graph->num_columns; i++) {
910 struct column *col = &graph->columns[i];
911 struct commit *col_commit;
912 if (i == graph->num_columns) {
913 if (seen_this)
914 break;
915 col_commit = graph->commit;
916 } else {
917 col_commit = col->commit;
920 if (col_commit == graph->commit) {
922 * Since the current commit is a merge find
923 * the columns for the parent commits in
924 * new_columns and use those to format the
925 * edges.
927 struct commit_list *parents = NULL;
928 struct column *par_column;
929 seen_this = 1;
930 parents = first_interesting_parent(graph);
931 assert(parents);
932 par_column = find_new_column_by_commit(graph, parents->item);
933 assert(par_column);
935 strbuf_write_column(sb, par_column, '|');
936 chars_written++;
937 for (j = 0; j < graph->num_parents - 1; j++) {
938 parents = next_interesting_parent(graph, parents);
939 assert(parents);
940 par_column = find_new_column_by_commit(graph, parents->item);
941 assert(par_column);
942 strbuf_write_column(sb, par_column, '\\');
943 strbuf_addch(sb, ' ');
945 chars_written += j * 2;
946 } else if (seen_this) {
947 strbuf_write_column(sb, col, '\\');
948 strbuf_addch(sb, ' ');
949 chars_written += 2;
950 } else {
951 strbuf_write_column(sb, col, '|');
952 strbuf_addch(sb, ' ');
953 chars_written += 2;
957 graph_pad_horizontally(graph, sb, chars_written);
960 * Update graph->state
962 if (graph_is_mapping_correct(graph))
963 graph_update_state(graph, GRAPH_PADDING);
964 else
965 graph_update_state(graph, GRAPH_COLLAPSING);
968 static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb)
970 int i;
971 int *tmp_mapping;
972 short used_horizontal = 0;
973 int horizontal_edge = -1;
974 int horizontal_edge_target = -1;
977 * Clear out the new_mapping array
979 for (i = 0; i < graph->mapping_size; i++)
980 graph->new_mapping[i] = -1;
982 for (i = 0; i < graph->mapping_size; i++) {
983 int target = graph->mapping[i];
984 if (target < 0)
985 continue;
988 * Since update_columns() always inserts the leftmost
989 * column first, each branch's target location should
990 * always be either its current location or to the left of
991 * its current location.
993 * We never have to move branches to the right. This makes
994 * the graph much more legible, since whenever branches
995 * cross, only one is moving directions.
997 assert(target * 2 <= i);
999 if (target * 2 == i) {
1001 * This column is already in the
1002 * correct place
1004 assert(graph->new_mapping[i] == -1);
1005 graph->new_mapping[i] = target;
1006 } else if (graph->new_mapping[i - 1] < 0) {
1008 * Nothing is to the left.
1009 * Move to the left by one
1011 graph->new_mapping[i - 1] = target;
1013 * If there isn't already an edge moving horizontally
1014 * select this one.
1016 if (horizontal_edge == -1) {
1017 int j;
1018 horizontal_edge = i;
1019 horizontal_edge_target = target;
1021 * The variable target is the index of the graph
1022 * column, and therefore target*2+3 is the
1023 * actual screen column of the first horizontal
1024 * line.
1026 for (j = (target * 2)+3; j < (i - 2); j += 2)
1027 graph->new_mapping[j] = target;
1029 } else if (graph->new_mapping[i - 1] == target) {
1031 * There is a branch line to our left
1032 * already, and it is our target. We
1033 * combine with this line, since we share
1034 * the same parent commit.
1036 * We don't have to add anything to the
1037 * output or new_mapping, since the
1038 * existing branch line has already taken
1039 * care of it.
1041 } else {
1043 * There is a branch line to our left,
1044 * but it isn't our target. We need to
1045 * cross over it.
1047 * The space just to the left of this
1048 * branch should always be empty.
1050 * The branch to the left of that space
1051 * should be our eventual target.
1053 assert(graph->new_mapping[i - 1] > target);
1054 assert(graph->new_mapping[i - 2] < 0);
1055 assert(graph->new_mapping[i - 3] == target);
1056 graph->new_mapping[i - 2] = target;
1058 * Mark this branch as the horizontal edge to
1059 * prevent any other edges from moving
1060 * horizontally.
1062 if (horizontal_edge == -1)
1063 horizontal_edge = i;
1068 * The new mapping may be 1 smaller than the old mapping
1070 if (graph->new_mapping[graph->mapping_size - 1] < 0)
1071 graph->mapping_size--;
1074 * Output out a line based on the new mapping info
1076 for (i = 0; i < graph->mapping_size; i++) {
1077 int target = graph->new_mapping[i];
1078 if (target < 0)
1079 strbuf_addch(sb, ' ');
1080 else if (target * 2 == i)
1081 strbuf_write_column(sb, &graph->new_columns[target], '|');
1082 else if (target == horizontal_edge_target &&
1083 i != horizontal_edge - 1) {
1085 * Set the mappings for all but the
1086 * first segment to -1 so that they
1087 * won't continue into the next line.
1089 if (i != (target * 2)+3)
1090 graph->new_mapping[i] = -1;
1091 used_horizontal = 1;
1092 strbuf_write_column(sb, &graph->new_columns[target], '_');
1093 } else {
1094 if (used_horizontal && i < horizontal_edge)
1095 graph->new_mapping[i] = -1;
1096 strbuf_write_column(sb, &graph->new_columns[target], '/');
1101 graph_pad_horizontally(graph, sb, graph->mapping_size);
1104 * Swap mapping and new_mapping
1106 tmp_mapping = graph->mapping;
1107 graph->mapping = graph->new_mapping;
1108 graph->new_mapping = tmp_mapping;
1111 * If graph->mapping indicates that all of the branch lines
1112 * are already in the correct positions, we are done.
1113 * Otherwise, we need to collapse some branch lines together.
1115 if (graph_is_mapping_correct(graph))
1116 graph_update_state(graph, GRAPH_PADDING);
1119 static int graph_next_line(struct git_graph *graph, struct strbuf *sb)
1121 switch (graph->state) {
1122 case GRAPH_PADDING:
1123 graph_output_padding_line(graph, sb);
1124 return 0;
1125 case GRAPH_SKIP:
1126 graph_output_skip_line(graph, sb);
1127 return 0;
1128 case GRAPH_PRE_COMMIT:
1129 graph_output_pre_commit_line(graph, sb);
1130 return 0;
1131 case GRAPH_COMMIT:
1132 graph_output_commit_line(graph, sb);
1133 return 1;
1134 case GRAPH_POST_MERGE:
1135 graph_output_post_merge_line(graph, sb);
1136 return 0;
1137 case GRAPH_COLLAPSING:
1138 graph_output_collapsing_line(graph, sb);
1139 return 0;
1142 assert(0);
1143 return 0;
1146 static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
1148 int i, j;
1150 if (graph->state != GRAPH_COMMIT) {
1151 graph_next_line(graph, sb);
1152 return;
1156 * Output the row containing this commit
1157 * Iterate up to and including graph->num_columns,
1158 * since the current commit may not be in any of the existing
1159 * columns. (This happens when the current commit doesn't have any
1160 * children that we have already processed.)
1162 for (i = 0; i < graph->num_columns; i++) {
1163 struct column *col = &graph->columns[i];
1164 struct commit *col_commit = col->commit;
1165 if (col_commit == graph->commit) {
1166 strbuf_write_column(sb, col, '|');
1168 if (graph->num_parents < 3)
1169 strbuf_addch(sb, ' ');
1170 else {
1171 int num_spaces = ((graph->num_parents - 2) * 2);
1172 for (j = 0; j < num_spaces; j++)
1173 strbuf_addch(sb, ' ');
1175 } else {
1176 strbuf_write_column(sb, col, '|');
1177 strbuf_addch(sb, ' ');
1181 graph_pad_horizontally(graph, sb, graph->num_columns);
1184 * Update graph->prev_state since we have output a padding line
1186 graph->prev_state = GRAPH_PADDING;
1189 int graph_is_commit_finished(struct git_graph const *graph)
1191 return (graph->state == GRAPH_PADDING);
1194 void graph_show_commit(struct git_graph *graph)
1196 struct strbuf msgbuf = STRBUF_INIT;
1197 int shown_commit_line = 0;
1199 if (!graph)
1200 return;
1202 while (!shown_commit_line) {
1203 shown_commit_line = graph_next_line(graph, &msgbuf);
1204 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1205 if (!shown_commit_line)
1206 putchar('\n');
1207 strbuf_setlen(&msgbuf, 0);
1210 strbuf_release(&msgbuf);
1213 void graph_show_oneline(struct git_graph *graph)
1215 struct strbuf msgbuf = STRBUF_INIT;
1217 if (!graph)
1218 return;
1220 graph_next_line(graph, &msgbuf);
1221 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1222 strbuf_release(&msgbuf);
1225 void graph_show_padding(struct git_graph *graph)
1227 struct strbuf msgbuf = STRBUF_INIT;
1229 if (!graph)
1230 return;
1232 graph_padding_line(graph, &msgbuf);
1233 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1234 strbuf_release(&msgbuf);
1237 int graph_show_remainder(struct git_graph *graph)
1239 struct strbuf msgbuf = STRBUF_INIT;
1240 int shown = 0;
1242 if (!graph)
1243 return 0;
1245 if (graph_is_commit_finished(graph))
1246 return 0;
1248 for (;;) {
1249 graph_next_line(graph, &msgbuf);
1250 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1251 strbuf_setlen(&msgbuf, 0);
1252 shown = 1;
1254 if (!graph_is_commit_finished(graph))
1255 putchar('\n');
1256 else
1257 break;
1259 strbuf_release(&msgbuf);
1261 return shown;
1265 static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb)
1267 char *p;
1269 if (!graph) {
1270 fwrite(sb->buf, sizeof(char), sb->len, stdout);
1271 return;
1275 * Print the strbuf line by line,
1276 * and display the graph info before each line but the first.
1278 p = sb->buf;
1279 while (p) {
1280 size_t len;
1281 char *next_p = strchr(p, '\n');
1282 if (next_p) {
1283 next_p++;
1284 len = next_p - p;
1285 } else {
1286 len = (sb->buf + sb->len) - p;
1288 fwrite(p, sizeof(char), len, stdout);
1289 if (next_p && *next_p != '\0')
1290 graph_show_oneline(graph);
1291 p = next_p;
1295 void graph_show_commit_msg(struct git_graph *graph,
1296 struct strbuf const *sb)
1298 int newline_terminated;
1300 if (!graph) {
1302 * If there's no graph, just print the message buffer.
1304 * The message buffer for CMIT_FMT_ONELINE and
1305 * CMIT_FMT_USERFORMAT are already missing a terminating
1306 * newline. All of the other formats should have it.
1308 fwrite(sb->buf, sizeof(char), sb->len, stdout);
1309 return;
1312 newline_terminated = (sb->len && sb->buf[sb->len - 1] == '\n');
1315 * Show the commit message
1317 graph_show_strbuf(graph, sb);
1320 * If there is more output needed for this commit, show it now
1322 if (!graph_is_commit_finished(graph)) {
1324 * If sb doesn't have a terminating newline, print one now,
1325 * so we can start the remainder of the graph output on a
1326 * new line.
1328 if (!newline_terminated)
1329 putchar('\n');
1331 graph_show_remainder(graph);
1334 * If sb ends with a newline, our output should too.
1336 if (newline_terminated)
1337 putchar('\n');