Merge branch 'cb/maint-orphan-merge-noclobber'
[git/kirr.git] / graph.c
blobf1a63c2241a30cce0141b87b5e8005b1a899a8ef
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
63 * The list of available column colors.
65 static const char *column_colors_ansi[] = {
66 GIT_COLOR_RED,
67 GIT_COLOR_GREEN,
68 GIT_COLOR_YELLOW,
69 GIT_COLOR_BLUE,
70 GIT_COLOR_MAGENTA,
71 GIT_COLOR_CYAN,
72 GIT_COLOR_BOLD_RED,
73 GIT_COLOR_BOLD_GREEN,
74 GIT_COLOR_BOLD_YELLOW,
75 GIT_COLOR_BOLD_BLUE,
76 GIT_COLOR_BOLD_MAGENTA,
77 GIT_COLOR_BOLD_CYAN,
78 GIT_COLOR_RESET,
81 #define COLUMN_COLORS_ANSI_MAX (ARRAY_SIZE(column_colors_ansi) - 1)
83 static const char **column_colors;
84 static unsigned short column_colors_max;
86 void graph_set_column_colors(const char **colors, unsigned short colors_max)
88 column_colors = colors;
89 column_colors_max = colors_max;
92 static const char *column_get_color_code(unsigned short color)
94 return column_colors[color];
97 static void strbuf_write_column(struct strbuf *sb, const struct column *c,
98 char col_char)
100 if (c->color < column_colors_max)
101 strbuf_addstr(sb, column_get_color_code(c->color));
102 strbuf_addch(sb, col_char);
103 if (c->color < column_colors_max)
104 strbuf_addstr(sb, column_get_color_code(column_colors_max));
107 struct git_graph {
109 * The commit currently being processed
111 struct commit *commit;
112 /* The rev-info used for the current traversal */
113 struct rev_info *revs;
115 * The number of interesting parents that this commit has.
117 * Note that this is not the same as the actual number of parents.
118 * This count excludes parents that won't be printed in the graph
119 * output, as determined by graph_is_interesting().
121 int num_parents;
123 * The width of the graph output for this commit.
124 * All rows for this commit are padded to this width, so that
125 * messages printed after the graph output are aligned.
127 int width;
129 * The next expansion row to print
130 * when state is GRAPH_PRE_COMMIT
132 int expansion_row;
134 * The current output state.
135 * This tells us what kind of line graph_next_line() should output.
137 enum graph_state state;
139 * The output state for the previous line of output.
140 * This is primarily used to determine how the first merge line
141 * should appear, based on the last line of the previous commit.
143 enum graph_state prev_state;
145 * The index of the column that refers to this commit.
147 * If none of the incoming columns refer to this commit,
148 * this will be equal to num_columns.
150 int commit_index;
152 * The commit_index for the previously displayed commit.
154 * This is used to determine how the first line of a merge
155 * graph output should appear, based on the last line of the
156 * previous commit.
158 int prev_commit_index;
160 * The maximum number of columns that can be stored in the columns
161 * and new_columns arrays. This is also half the number of entries
162 * that can be stored in the mapping and new_mapping arrays.
164 int column_capacity;
166 * The number of columns (also called "branch lines" in some places)
168 int num_columns;
170 * The number of columns in the new_columns array
172 int num_new_columns;
174 * The number of entries in the mapping array
176 int mapping_size;
178 * The column state before we output the current commit.
180 struct column *columns;
182 * The new column state after we output the current commit.
183 * Only valid when state is GRAPH_COLLAPSING.
185 struct column *new_columns;
187 * An array that tracks the current state of each
188 * character in the output line during state GRAPH_COLLAPSING.
189 * Each entry is -1 if this character is empty, or a non-negative
190 * integer if the character contains a branch line. The value of
191 * the integer indicates the target position for this branch line.
192 * (I.e., this array maps the current column positions to their
193 * desired positions.)
195 * The maximum capacity of this array is always
196 * sizeof(int) * 2 * column_capacity.
198 int *mapping;
200 * A temporary array for computing the next mapping state
201 * while we are outputting a mapping line. This is stored as part
202 * of the git_graph simply so we don't have to allocate a new
203 * temporary array each time we have to output a collapsing line.
205 int *new_mapping;
207 * The current default column color being used. This is
208 * stored as an index into the array column_colors.
210 unsigned short default_column_color;
213 static struct strbuf *diff_output_prefix_callback(struct diff_options *opt, void *data)
215 struct git_graph *graph = data;
216 static struct strbuf msgbuf = STRBUF_INIT;
218 assert(graph);
220 strbuf_reset(&msgbuf);
221 graph_padding_line(graph, &msgbuf);
222 return &msgbuf;
225 struct git_graph *graph_init(struct rev_info *opt)
227 struct git_graph *graph = xmalloc(sizeof(struct git_graph));
229 if (!column_colors)
230 graph_set_column_colors(column_colors_ansi,
231 COLUMN_COLORS_ANSI_MAX);
233 graph->commit = NULL;
234 graph->revs = opt;
235 graph->num_parents = 0;
236 graph->expansion_row = 0;
237 graph->state = GRAPH_PADDING;
238 graph->prev_state = GRAPH_PADDING;
239 graph->commit_index = 0;
240 graph->prev_commit_index = 0;
241 graph->num_columns = 0;
242 graph->num_new_columns = 0;
243 graph->mapping_size = 0;
245 * Start the column color at the maximum value, since we'll
246 * always increment it for the first commit we output.
247 * This way we start at 0 for the first commit.
249 graph->default_column_color = column_colors_max - 1;
252 * Allocate a reasonably large default number of columns
253 * We'll automatically grow columns later if we need more room.
255 graph->column_capacity = 30;
256 graph->columns = xmalloc(sizeof(struct column) *
257 graph->column_capacity);
258 graph->new_columns = xmalloc(sizeof(struct column) *
259 graph->column_capacity);
260 graph->mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
261 graph->new_mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
264 * The diff output prefix callback, with this we can make
265 * all the diff output to align with the graph lines.
267 opt->diffopt.output_prefix = diff_output_prefix_callback;
268 opt->diffopt.output_prefix_data = graph;
270 return graph;
273 static void graph_update_state(struct git_graph *graph, enum graph_state s)
275 graph->prev_state = graph->state;
276 graph->state = s;
279 static void graph_ensure_capacity(struct git_graph *graph, int num_columns)
281 if (graph->column_capacity >= num_columns)
282 return;
284 do {
285 graph->column_capacity *= 2;
286 } while (graph->column_capacity < num_columns);
288 graph->columns = xrealloc(graph->columns,
289 sizeof(struct column) *
290 graph->column_capacity);
291 graph->new_columns = xrealloc(graph->new_columns,
292 sizeof(struct column) *
293 graph->column_capacity);
294 graph->mapping = xrealloc(graph->mapping,
295 sizeof(int) * 2 * graph->column_capacity);
296 graph->new_mapping = xrealloc(graph->new_mapping,
297 sizeof(int) * 2 * graph->column_capacity);
301 * Returns 1 if the commit will be printed in the graph output,
302 * and 0 otherwise.
304 static int graph_is_interesting(struct git_graph *graph, struct commit *commit)
307 * If revs->boundary is set, commits whose children have
308 * been shown are always interesting, even if they have the
309 * UNINTERESTING or TREESAME flags set.
311 if (graph->revs && graph->revs->boundary) {
312 if (commit->object.flags & CHILD_SHOWN)
313 return 1;
317 * Otherwise, use get_commit_action() to see if this commit is
318 * interesting
320 return get_commit_action(graph->revs, commit) == commit_show;
323 static struct commit_list *next_interesting_parent(struct git_graph *graph,
324 struct commit_list *orig)
326 struct commit_list *list;
329 * If revs->first_parent_only is set, only the first
330 * parent is interesting. None of the others are.
332 if (graph->revs->first_parent_only)
333 return NULL;
336 * Return the next interesting commit after orig
338 for (list = orig->next; list; list = list->next) {
339 if (graph_is_interesting(graph, list->item))
340 return list;
343 return NULL;
346 static struct commit_list *first_interesting_parent(struct git_graph *graph)
348 struct commit_list *parents = graph->commit->parents;
351 * If this commit has no parents, ignore it
353 if (!parents)
354 return NULL;
357 * If the first parent is interesting, return it
359 if (graph_is_interesting(graph, parents->item))
360 return parents;
363 * Otherwise, call next_interesting_parent() to get
364 * the next interesting parent
366 return next_interesting_parent(graph, parents);
369 static unsigned short graph_get_current_column_color(const struct git_graph *graph)
371 if (!DIFF_OPT_TST(&graph->revs->diffopt, COLOR_DIFF))
372 return column_colors_max;
373 return graph->default_column_color;
377 * Update the graph's default column color.
379 static void graph_increment_column_color(struct git_graph *graph)
381 graph->default_column_color = (graph->default_column_color + 1) %
382 column_colors_max;
385 static unsigned short graph_find_commit_color(const struct git_graph *graph,
386 const struct commit *commit)
388 int i;
389 for (i = 0; i < graph->num_columns; i++) {
390 if (graph->columns[i].commit == commit)
391 return graph->columns[i].color;
393 return graph_get_current_column_color(graph);
396 static void graph_insert_into_new_columns(struct git_graph *graph,
397 struct commit *commit,
398 int *mapping_index)
400 int i;
403 * If the commit is already in the new_columns list, we don't need to
404 * add it. Just update the mapping correctly.
406 for (i = 0; i < graph->num_new_columns; i++) {
407 if (graph->new_columns[i].commit == commit) {
408 graph->mapping[*mapping_index] = i;
409 *mapping_index += 2;
410 return;
415 * This commit isn't already in new_columns. Add it.
417 graph->new_columns[graph->num_new_columns].commit = commit;
418 graph->new_columns[graph->num_new_columns].color = graph_find_commit_color(graph, commit);
419 graph->mapping[*mapping_index] = graph->num_new_columns;
420 *mapping_index += 2;
421 graph->num_new_columns++;
424 static void graph_update_width(struct git_graph *graph,
425 int is_commit_in_existing_columns)
428 * Compute the width needed to display the graph for this commit.
429 * This is the maximum width needed for any row. All other rows
430 * will be padded to this width.
432 * Compute the number of columns in the widest row:
433 * Count each existing column (graph->num_columns), and each new
434 * column added by this commit.
436 int max_cols = graph->num_columns + graph->num_parents;
439 * Even if the current commit has no parents to be printed, it
440 * still takes up a column for itself.
442 if (graph->num_parents < 1)
443 max_cols++;
446 * We added a column for the current commit as part of
447 * graph->num_parents. If the current commit was already in
448 * graph->columns, then we have double counted it.
450 if (is_commit_in_existing_columns)
451 max_cols--;
454 * Each column takes up 2 spaces
456 graph->width = max_cols * 2;
459 static void graph_update_columns(struct git_graph *graph)
461 struct commit_list *parent;
462 struct column *tmp_columns;
463 int max_new_columns;
464 int mapping_idx;
465 int i, seen_this, is_commit_in_columns;
468 * Swap graph->columns with graph->new_columns
469 * graph->columns contains the state for the previous commit,
470 * and new_columns now contains the state for our commit.
472 * We'll re-use the old columns array as storage to compute the new
473 * columns list for the commit after this one.
475 tmp_columns = graph->columns;
476 graph->columns = graph->new_columns;
477 graph->num_columns = graph->num_new_columns;
479 graph->new_columns = tmp_columns;
480 graph->num_new_columns = 0;
483 * Now update new_columns and mapping with the information for the
484 * commit after this one.
486 * First, make sure we have enough room. At most, there will
487 * be graph->num_columns + graph->num_parents columns for the next
488 * commit.
490 max_new_columns = graph->num_columns + graph->num_parents;
491 graph_ensure_capacity(graph, max_new_columns);
494 * Clear out graph->mapping
496 graph->mapping_size = 2 * max_new_columns;
497 for (i = 0; i < graph->mapping_size; i++)
498 graph->mapping[i] = -1;
501 * Populate graph->new_columns and graph->mapping
503 * Some of the parents of this commit may already be in
504 * graph->columns. If so, graph->new_columns should only contain a
505 * single entry for each such commit. graph->mapping should
506 * contain information about where each current branch line is
507 * supposed to end up after the collapsing is performed.
509 seen_this = 0;
510 mapping_idx = 0;
511 is_commit_in_columns = 1;
512 for (i = 0; i <= graph->num_columns; i++) {
513 struct commit *col_commit;
514 if (i == graph->num_columns) {
515 if (seen_this)
516 break;
517 is_commit_in_columns = 0;
518 col_commit = graph->commit;
519 } else {
520 col_commit = graph->columns[i].commit;
523 if (col_commit == graph->commit) {
524 int old_mapping_idx = mapping_idx;
525 seen_this = 1;
526 graph->commit_index = i;
527 for (parent = first_interesting_parent(graph);
528 parent;
529 parent = next_interesting_parent(graph, parent)) {
531 * If this is a merge, or the start of a new
532 * childless column, increment the current
533 * color.
535 if (graph->num_parents > 1 ||
536 !is_commit_in_columns) {
537 graph_increment_column_color(graph);
539 graph_insert_into_new_columns(graph,
540 parent->item,
541 &mapping_idx);
544 * We always need to increment mapping_idx by at
545 * least 2, even if it has no interesting parents.
546 * The current commit always takes up at least 2
547 * spaces.
549 if (mapping_idx == old_mapping_idx)
550 mapping_idx += 2;
551 } else {
552 graph_insert_into_new_columns(graph, col_commit,
553 &mapping_idx);
558 * Shrink mapping_size to be the minimum necessary
560 while (graph->mapping_size > 1 &&
561 graph->mapping[graph->mapping_size - 1] < 0)
562 graph->mapping_size--;
565 * Compute graph->width for this commit
567 graph_update_width(graph, is_commit_in_columns);
570 void graph_update(struct git_graph *graph, struct commit *commit)
572 struct commit_list *parent;
575 * Set the new commit
577 graph->commit = commit;
580 * Count how many interesting parents this commit has
582 graph->num_parents = 0;
583 for (parent = first_interesting_parent(graph);
584 parent;
585 parent = next_interesting_parent(graph, parent))
587 graph->num_parents++;
591 * Store the old commit_index in prev_commit_index.
592 * graph_update_columns() will update graph->commit_index for this
593 * commit.
595 graph->prev_commit_index = graph->commit_index;
598 * Call graph_update_columns() to update
599 * columns, new_columns, and mapping.
601 graph_update_columns(graph);
603 graph->expansion_row = 0;
606 * Update graph->state.
607 * Note that we don't call graph_update_state() here, since
608 * we don't want to update graph->prev_state. No line for
609 * graph->state was ever printed.
611 * If the previous commit didn't get to the GRAPH_PADDING state,
612 * it never finished its output. Goto GRAPH_SKIP, to print out
613 * a line to indicate that portion of the graph is missing.
615 * If there are 3 or more parents, we may need to print extra rows
616 * before the commit, to expand the branch lines around it and make
617 * room for it. We need to do this only if there is a branch row
618 * (or more) to the right of this commit.
620 * If there are less than 3 parents, we can immediately print the
621 * commit line.
623 if (graph->state != GRAPH_PADDING)
624 graph->state = GRAPH_SKIP;
625 else if (graph->num_parents >= 3 &&
626 graph->commit_index < (graph->num_columns - 1))
627 graph->state = GRAPH_PRE_COMMIT;
628 else
629 graph->state = GRAPH_COMMIT;
632 static int graph_is_mapping_correct(struct git_graph *graph)
634 int i;
637 * The mapping is up to date if each entry is at its target,
638 * or is 1 greater than its target.
639 * (If it is 1 greater than the target, '/' will be printed, so it
640 * will look correct on the next row.)
642 for (i = 0; i < graph->mapping_size; i++) {
643 int target = graph->mapping[i];
644 if (target < 0)
645 continue;
646 if (target == (i / 2))
647 continue;
648 return 0;
651 return 1;
654 static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb,
655 int chars_written)
658 * Add additional spaces to the end of the strbuf, so that all
659 * lines for a particular commit have the same width.
661 * This way, fields printed to the right of the graph will remain
662 * aligned for the entire commit.
664 int extra;
665 if (chars_written >= graph->width)
666 return;
668 extra = graph->width - chars_written;
669 strbuf_addf(sb, "%*s", (int) extra, "");
672 static void graph_output_padding_line(struct git_graph *graph,
673 struct strbuf *sb)
675 int i;
678 * We could conceivable be called with a NULL commit
679 * if our caller has a bug, and invokes graph_next_line()
680 * immediately after graph_init(), without first calling
681 * graph_update(). Return without outputting anything in this
682 * case.
684 if (!graph->commit)
685 return;
688 * Output a padding row, that leaves all branch lines unchanged
690 for (i = 0; i < graph->num_new_columns; i++) {
691 strbuf_write_column(sb, &graph->new_columns[i], '|');
692 strbuf_addch(sb, ' ');
695 graph_pad_horizontally(graph, sb, graph->num_new_columns * 2);
698 static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
701 * Output an ellipsis to indicate that a portion
702 * of the graph is missing.
704 strbuf_addstr(sb, "...");
705 graph_pad_horizontally(graph, sb, 3);
707 if (graph->num_parents >= 3 &&
708 graph->commit_index < (graph->num_columns - 1))
709 graph_update_state(graph, GRAPH_PRE_COMMIT);
710 else
711 graph_update_state(graph, GRAPH_COMMIT);
714 static void graph_output_pre_commit_line(struct git_graph *graph,
715 struct strbuf *sb)
717 int num_expansion_rows;
718 int i, seen_this;
719 int chars_written;
722 * This function formats a row that increases the space around a commit
723 * with multiple parents, to make room for it. It should only be
724 * called when there are 3 or more parents.
726 * We need 2 extra rows for every parent over 2.
728 assert(graph->num_parents >= 3);
729 num_expansion_rows = (graph->num_parents - 2) * 2;
732 * graph->expansion_row tracks the current expansion row we are on.
733 * It should be in the range [0, num_expansion_rows - 1]
735 assert(0 <= graph->expansion_row &&
736 graph->expansion_row < num_expansion_rows);
739 * Output the row
741 seen_this = 0;
742 chars_written = 0;
743 for (i = 0; i < graph->num_columns; i++) {
744 struct column *col = &graph->columns[i];
745 if (col->commit == graph->commit) {
746 seen_this = 1;
747 strbuf_write_column(sb, col, '|');
748 strbuf_addf(sb, "%*s", graph->expansion_row, "");
749 chars_written += 1 + graph->expansion_row;
750 } else if (seen_this && (graph->expansion_row == 0)) {
752 * This is the first line of the pre-commit output.
753 * If the previous commit was a merge commit and
754 * ended in the GRAPH_POST_MERGE state, all branch
755 * lines after graph->prev_commit_index were
756 * printed as "\" on the previous line. Continue
757 * to print them as "\" on this line. Otherwise,
758 * print the branch lines as "|".
760 if (graph->prev_state == GRAPH_POST_MERGE &&
761 graph->prev_commit_index < i)
762 strbuf_write_column(sb, col, '\\');
763 else
764 strbuf_write_column(sb, col, '|');
765 chars_written++;
766 } else if (seen_this && (graph->expansion_row > 0)) {
767 strbuf_write_column(sb, col, '\\');
768 chars_written++;
769 } else {
770 strbuf_write_column(sb, col, '|');
771 chars_written++;
773 strbuf_addch(sb, ' ');
774 chars_written++;
777 graph_pad_horizontally(graph, sb, chars_written);
780 * Increment graph->expansion_row,
781 * and move to state GRAPH_COMMIT if necessary
783 graph->expansion_row++;
784 if (graph->expansion_row >= num_expansion_rows)
785 graph_update_state(graph, GRAPH_COMMIT);
788 static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
791 * For boundary commits, print 'o'
792 * (We should only see boundary commits when revs->boundary is set.)
794 if (graph->commit->object.flags & BOUNDARY) {
795 assert(graph->revs->boundary);
796 strbuf_addch(sb, 'o');
797 return;
801 * If revs->left_right is set, print '<' for commits that
802 * come from the left side, and '>' for commits from the right
803 * side.
805 if (graph->revs && graph->revs->left_right) {
806 if (graph->commit->object.flags & SYMMETRIC_LEFT)
807 strbuf_addch(sb, '<');
808 else
809 strbuf_addch(sb, '>');
810 return;
814 * Print '*' in all other cases
816 strbuf_addch(sb, '*');
820 * Draw an octopus merge and return the number of characters written.
822 static int graph_draw_octopus_merge(struct git_graph *graph,
823 struct strbuf *sb)
826 * Here dashless_commits represents the number of parents
827 * which don't need to have dashes (because their edges fit
828 * neatly under the commit).
830 const int dashless_commits = 2;
831 int col_num, i;
832 int num_dashes =
833 ((graph->num_parents - dashless_commits) * 2) - 1;
834 for (i = 0; i < num_dashes; i++) {
835 col_num = (i / 2) + dashless_commits;
836 strbuf_write_column(sb, &graph->new_columns[col_num], '-');
838 col_num = (i / 2) + dashless_commits;
839 strbuf_write_column(sb, &graph->new_columns[col_num], '.');
840 return num_dashes + 1;
843 static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
845 int seen_this = 0;
846 int i, chars_written;
849 * Output the row containing this commit
850 * Iterate up to and including graph->num_columns,
851 * since the current commit may not be in any of the existing
852 * columns. (This happens when the current commit doesn't have any
853 * children that we have already processed.)
855 seen_this = 0;
856 chars_written = 0;
857 for (i = 0; i <= graph->num_columns; i++) {
858 struct column *col = &graph->columns[i];
859 struct commit *col_commit;
860 if (i == graph->num_columns) {
861 if (seen_this)
862 break;
863 col_commit = graph->commit;
864 } else {
865 col_commit = graph->columns[i].commit;
868 if (col_commit == graph->commit) {
869 seen_this = 1;
870 graph_output_commit_char(graph, sb);
871 chars_written++;
873 if (graph->num_parents > 2)
874 chars_written += graph_draw_octopus_merge(graph,
875 sb);
876 } else if (seen_this && (graph->num_parents > 2)) {
877 strbuf_write_column(sb, col, '\\');
878 chars_written++;
879 } else if (seen_this && (graph->num_parents == 2)) {
881 * This is a 2-way merge commit.
882 * There is no GRAPH_PRE_COMMIT stage for 2-way
883 * merges, so this is the first line of output
884 * for this commit. Check to see what the previous
885 * line of output was.
887 * If it was GRAPH_POST_MERGE, the branch line
888 * coming into this commit may have been '\',
889 * and not '|' or '/'. If so, output the branch
890 * line as '\' on this line, instead of '|'. This
891 * makes the output look nicer.
893 if (graph->prev_state == GRAPH_POST_MERGE &&
894 graph->prev_commit_index < i)
895 strbuf_write_column(sb, col, '\\');
896 else
897 strbuf_write_column(sb, col, '|');
898 chars_written++;
899 } else {
900 strbuf_write_column(sb, col, '|');
901 chars_written++;
903 strbuf_addch(sb, ' ');
904 chars_written++;
907 graph_pad_horizontally(graph, sb, chars_written);
910 * Update graph->state
912 if (graph->num_parents > 1)
913 graph_update_state(graph, GRAPH_POST_MERGE);
914 else if (graph_is_mapping_correct(graph))
915 graph_update_state(graph, GRAPH_PADDING);
916 else
917 graph_update_state(graph, GRAPH_COLLAPSING);
920 static struct column *find_new_column_by_commit(struct git_graph *graph,
921 struct commit *commit)
923 int i;
924 for (i = 0; i < graph->num_new_columns; i++) {
925 if (graph->new_columns[i].commit == commit)
926 return &graph->new_columns[i];
928 return NULL;
931 static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
933 int seen_this = 0;
934 int i, j, chars_written;
937 * Output the post-merge row
939 chars_written = 0;
940 for (i = 0; i <= graph->num_columns; i++) {
941 struct column *col = &graph->columns[i];
942 struct commit *col_commit;
943 if (i == graph->num_columns) {
944 if (seen_this)
945 break;
946 col_commit = graph->commit;
947 } else {
948 col_commit = col->commit;
951 if (col_commit == graph->commit) {
953 * Since the current commit is a merge find
954 * the columns for the parent commits in
955 * new_columns and use those to format the
956 * edges.
958 struct commit_list *parents = NULL;
959 struct column *par_column;
960 seen_this = 1;
961 parents = first_interesting_parent(graph);
962 assert(parents);
963 par_column = find_new_column_by_commit(graph, parents->item);
964 assert(par_column);
966 strbuf_write_column(sb, par_column, '|');
967 chars_written++;
968 for (j = 0; j < graph->num_parents - 1; j++) {
969 parents = next_interesting_parent(graph, parents);
970 assert(parents);
971 par_column = find_new_column_by_commit(graph, parents->item);
972 assert(par_column);
973 strbuf_write_column(sb, par_column, '\\');
974 strbuf_addch(sb, ' ');
976 chars_written += j * 2;
977 } else if (seen_this) {
978 strbuf_write_column(sb, col, '\\');
979 strbuf_addch(sb, ' ');
980 chars_written += 2;
981 } else {
982 strbuf_write_column(sb, col, '|');
983 strbuf_addch(sb, ' ');
984 chars_written += 2;
988 graph_pad_horizontally(graph, sb, chars_written);
991 * Update graph->state
993 if (graph_is_mapping_correct(graph))
994 graph_update_state(graph, GRAPH_PADDING);
995 else
996 graph_update_state(graph, GRAPH_COLLAPSING);
999 static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb)
1001 int i;
1002 int *tmp_mapping;
1003 short used_horizontal = 0;
1004 int horizontal_edge = -1;
1005 int horizontal_edge_target = -1;
1008 * Clear out the new_mapping array
1010 for (i = 0; i < graph->mapping_size; i++)
1011 graph->new_mapping[i] = -1;
1013 for (i = 0; i < graph->mapping_size; i++) {
1014 int target = graph->mapping[i];
1015 if (target < 0)
1016 continue;
1019 * Since update_columns() always inserts the leftmost
1020 * column first, each branch's target location should
1021 * always be either its current location or to the left of
1022 * its current location.
1024 * We never have to move branches to the right. This makes
1025 * the graph much more legible, since whenever branches
1026 * cross, only one is moving directions.
1028 assert(target * 2 <= i);
1030 if (target * 2 == i) {
1032 * This column is already in the
1033 * correct place
1035 assert(graph->new_mapping[i] == -1);
1036 graph->new_mapping[i] = target;
1037 } else if (graph->new_mapping[i - 1] < 0) {
1039 * Nothing is to the left.
1040 * Move to the left by one
1042 graph->new_mapping[i - 1] = target;
1044 * If there isn't already an edge moving horizontally
1045 * select this one.
1047 if (horizontal_edge == -1) {
1048 int j;
1049 horizontal_edge = i;
1050 horizontal_edge_target = target;
1052 * The variable target is the index of the graph
1053 * column, and therefore target*2+3 is the
1054 * actual screen column of the first horizontal
1055 * line.
1057 for (j = (target * 2)+3; j < (i - 2); j += 2)
1058 graph->new_mapping[j] = target;
1060 } else if (graph->new_mapping[i - 1] == target) {
1062 * There is a branch line to our left
1063 * already, and it is our target. We
1064 * combine with this line, since we share
1065 * the same parent commit.
1067 * We don't have to add anything to the
1068 * output or new_mapping, since the
1069 * existing branch line has already taken
1070 * care of it.
1072 } else {
1074 * There is a branch line to our left,
1075 * but it isn't our target. We need to
1076 * cross over it.
1078 * The space just to the left of this
1079 * branch should always be empty.
1081 * The branch to the left of that space
1082 * should be our eventual target.
1084 assert(graph->new_mapping[i - 1] > target);
1085 assert(graph->new_mapping[i - 2] < 0);
1086 assert(graph->new_mapping[i - 3] == target);
1087 graph->new_mapping[i - 2] = target;
1089 * Mark this branch as the horizontal edge to
1090 * prevent any other edges from moving
1091 * horizontally.
1093 if (horizontal_edge == -1)
1094 horizontal_edge = i;
1099 * The new mapping may be 1 smaller than the old mapping
1101 if (graph->new_mapping[graph->mapping_size - 1] < 0)
1102 graph->mapping_size--;
1105 * Output out a line based on the new mapping info
1107 for (i = 0; i < graph->mapping_size; i++) {
1108 int target = graph->new_mapping[i];
1109 if (target < 0)
1110 strbuf_addch(sb, ' ');
1111 else if (target * 2 == i)
1112 strbuf_write_column(sb, &graph->new_columns[target], '|');
1113 else if (target == horizontal_edge_target &&
1114 i != horizontal_edge - 1) {
1116 * Set the mappings for all but the
1117 * first segment to -1 so that they
1118 * won't continue into the next line.
1120 if (i != (target * 2)+3)
1121 graph->new_mapping[i] = -1;
1122 used_horizontal = 1;
1123 strbuf_write_column(sb, &graph->new_columns[target], '_');
1124 } else {
1125 if (used_horizontal && i < horizontal_edge)
1126 graph->new_mapping[i] = -1;
1127 strbuf_write_column(sb, &graph->new_columns[target], '/');
1132 graph_pad_horizontally(graph, sb, graph->mapping_size);
1135 * Swap mapping and new_mapping
1137 tmp_mapping = graph->mapping;
1138 graph->mapping = graph->new_mapping;
1139 graph->new_mapping = tmp_mapping;
1142 * If graph->mapping indicates that all of the branch lines
1143 * are already in the correct positions, we are done.
1144 * Otherwise, we need to collapse some branch lines together.
1146 if (graph_is_mapping_correct(graph))
1147 graph_update_state(graph, GRAPH_PADDING);
1150 int graph_next_line(struct git_graph *graph, struct strbuf *sb)
1152 switch (graph->state) {
1153 case GRAPH_PADDING:
1154 graph_output_padding_line(graph, sb);
1155 return 0;
1156 case GRAPH_SKIP:
1157 graph_output_skip_line(graph, sb);
1158 return 0;
1159 case GRAPH_PRE_COMMIT:
1160 graph_output_pre_commit_line(graph, sb);
1161 return 0;
1162 case GRAPH_COMMIT:
1163 graph_output_commit_line(graph, sb);
1164 return 1;
1165 case GRAPH_POST_MERGE:
1166 graph_output_post_merge_line(graph, sb);
1167 return 0;
1168 case GRAPH_COLLAPSING:
1169 graph_output_collapsing_line(graph, sb);
1170 return 0;
1173 assert(0);
1174 return 0;
1177 static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
1179 int i, j;
1181 if (graph->state != GRAPH_COMMIT) {
1182 graph_next_line(graph, sb);
1183 return;
1187 * Output the row containing this commit
1188 * Iterate up to and including graph->num_columns,
1189 * since the current commit may not be in any of the existing
1190 * columns. (This happens when the current commit doesn't have any
1191 * children that we have already processed.)
1193 for (i = 0; i < graph->num_columns; i++) {
1194 struct column *col = &graph->columns[i];
1195 struct commit *col_commit = col->commit;
1196 if (col_commit == graph->commit) {
1197 strbuf_write_column(sb, col, '|');
1199 if (graph->num_parents < 3)
1200 strbuf_addch(sb, ' ');
1201 else {
1202 int num_spaces = ((graph->num_parents - 2) * 2);
1203 for (j = 0; j < num_spaces; j++)
1204 strbuf_addch(sb, ' ');
1206 } else {
1207 strbuf_write_column(sb, col, '|');
1208 strbuf_addch(sb, ' ');
1212 graph_pad_horizontally(graph, sb, graph->num_columns);
1215 * Update graph->prev_state since we have output a padding line
1217 graph->prev_state = GRAPH_PADDING;
1220 int graph_is_commit_finished(struct git_graph const *graph)
1222 return (graph->state == GRAPH_PADDING);
1225 void graph_show_commit(struct git_graph *graph)
1227 struct strbuf msgbuf = STRBUF_INIT;
1228 int shown_commit_line = 0;
1230 if (!graph)
1231 return;
1233 while (!shown_commit_line) {
1234 shown_commit_line = graph_next_line(graph, &msgbuf);
1235 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1236 if (!shown_commit_line)
1237 putchar('\n');
1238 strbuf_setlen(&msgbuf, 0);
1241 strbuf_release(&msgbuf);
1244 void graph_show_oneline(struct git_graph *graph)
1246 struct strbuf msgbuf = STRBUF_INIT;
1248 if (!graph)
1249 return;
1251 graph_next_line(graph, &msgbuf);
1252 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1253 strbuf_release(&msgbuf);
1256 void graph_show_padding(struct git_graph *graph)
1258 struct strbuf msgbuf = STRBUF_INIT;
1260 if (!graph)
1261 return;
1263 graph_padding_line(graph, &msgbuf);
1264 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1265 strbuf_release(&msgbuf);
1268 int graph_show_remainder(struct git_graph *graph)
1270 struct strbuf msgbuf = STRBUF_INIT;
1271 int shown = 0;
1273 if (!graph)
1274 return 0;
1276 if (graph_is_commit_finished(graph))
1277 return 0;
1279 for (;;) {
1280 graph_next_line(graph, &msgbuf);
1281 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1282 strbuf_setlen(&msgbuf, 0);
1283 shown = 1;
1285 if (!graph_is_commit_finished(graph))
1286 putchar('\n');
1287 else
1288 break;
1290 strbuf_release(&msgbuf);
1292 return shown;
1296 static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb)
1298 char *p;
1300 if (!graph) {
1301 fwrite(sb->buf, sizeof(char), sb->len, stdout);
1302 return;
1306 * Print the strbuf line by line,
1307 * and display the graph info before each line but the first.
1309 p = sb->buf;
1310 while (p) {
1311 size_t len;
1312 char *next_p = strchr(p, '\n');
1313 if (next_p) {
1314 next_p++;
1315 len = next_p - p;
1316 } else {
1317 len = (sb->buf + sb->len) - p;
1319 fwrite(p, sizeof(char), len, stdout);
1320 if (next_p && *next_p != '\0')
1321 graph_show_oneline(graph);
1322 p = next_p;
1326 void graph_show_commit_msg(struct git_graph *graph,
1327 struct strbuf const *sb)
1329 int newline_terminated;
1331 if (!graph) {
1333 * If there's no graph, just print the message buffer.
1335 * The message buffer for CMIT_FMT_ONELINE and
1336 * CMIT_FMT_USERFORMAT are already missing a terminating
1337 * newline. All of the other formats should have it.
1339 fwrite(sb->buf, sizeof(char), sb->len, stdout);
1340 return;
1343 newline_terminated = (sb->len && sb->buf[sb->len - 1] == '\n');
1346 * Show the commit message
1348 graph_show_strbuf(graph, sb);
1351 * If there is more output needed for this commit, show it now
1353 if (!graph_is_commit_finished(graph)) {
1355 * If sb doesn't have a terminating newline, print one now,
1356 * so we can start the remainder of the graph output on a
1357 * new line.
1359 if (!newline_terminated)
1360 putchar('\n');
1362 graph_show_remainder(graph);
1365 * If sb ends with a newline, our output should too.
1367 if (newline_terminated)
1368 putchar('\n');