Make graph_next_line() available in the graph.h API
[git/git.git] / graph.c
CommitLineData
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1#include "cache.h"
2#include "commit.h"
427fc5b8 3#include "color.h"
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4#include "graph.h"
5#include "diff.h"
6#include "revision.h"
7
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8/* Internal API */
9
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10/*
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.
16 */
17static void graph_padding_line(struct git_graph *graph, struct strbuf *sb);
18
19/*
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.
22 *
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.
26 *
3ea3c215 27 * Since the first line will not include the graph output, the caller is
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28 * responsible for printing this line's graph (perhaps via
29 * graph_show_commit() or graph_show_oneline()) before calling
30 * graph_show_strbuf().
31 */
32static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb);
33
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34/*
35 * TODO:
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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.
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39 */
40
41struct column {
42 /*
43 * The parent commit of this column.
44 */
45 struct commit *commit;
46 /*
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47 * The color to (optionally) print this column in. This is an
48 * index into column_colors.
c12172d2 49 */
427fc5b8 50 unsigned short color;
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51};
52
53enum graph_state {
54 GRAPH_PADDING,
55 GRAPH_SKIP,
56 GRAPH_PRE_COMMIT,
57 GRAPH_COMMIT,
58 GRAPH_POST_MERGE,
59 GRAPH_COLLAPSING
60};
61
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62/*
63 * The list of available column colors.
64 */
65static char column_colors[][COLOR_MAXLEN] = {
66 GIT_COLOR_RED,
67 GIT_COLOR_GREEN,
68 GIT_COLOR_YELLOW,
69 GIT_COLOR_BLUE,
70 GIT_COLOR_MAGENTA,
71 GIT_COLOR_CYAN,
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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,
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78};
79
80#define COLUMN_COLORS_MAX (ARRAY_SIZE(column_colors))
81
82static const char *column_get_color_code(const struct column *c)
83{
84 return column_colors[c->color];
85}
86
87static void strbuf_write_column(struct strbuf *sb, const struct column *c,
88 char col_char)
89{
90 if (c->color < COLUMN_COLORS_MAX)
91 strbuf_addstr(sb, column_get_color_code(c));
92 strbuf_addch(sb, col_char);
93 if (c->color < COLUMN_COLORS_MAX)
94 strbuf_addstr(sb, GIT_COLOR_RESET);
95}
96
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97struct git_graph {
98 /*
99 * The commit currently being processed
100 */
101 struct commit *commit;
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102 /* The rev-info used for the current traversal */
103 struct rev_info *revs;
c12172d2 104 /*
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105 * The number of interesting parents that this commit has.
106 *
107 * Note that this is not the same as the actual number of parents.
108 * This count excludes parents that won't be printed in the graph
109 * output, as determined by graph_is_interesting().
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110 */
111 int num_parents;
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112 /*
113 * The width of the graph output for this commit.
114 * All rows for this commit are padded to this width, so that
115 * messages printed after the graph output are aligned.
116 */
117 int width;
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118 /*
119 * The next expansion row to print
120 * when state is GRAPH_PRE_COMMIT
121 */
122 int expansion_row;
123 /*
124 * The current output state.
125 * This tells us what kind of line graph_next_line() should output.
126 */
127 enum graph_state state;
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128 /*
129 * The output state for the previous line of output.
130 * This is primarily used to determine how the first merge line
131 * should appear, based on the last line of the previous commit.
132 */
133 enum graph_state prev_state;
134 /*
135 * The index of the column that refers to this commit.
136 *
137 * If none of the incoming columns refer to this commit,
138 * this will be equal to num_columns.
139 */
140 int commit_index;
141 /*
142 * The commit_index for the previously displayed commit.
143 *
144 * This is used to determine how the first line of a merge
145 * graph output should appear, based on the last line of the
146 * previous commit.
147 */
148 int prev_commit_index;
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149 /*
150 * The maximum number of columns that can be stored in the columns
151 * and new_columns arrays. This is also half the number of entries
152 * that can be stored in the mapping and new_mapping arrays.
153 */
154 int column_capacity;
155 /*
156 * The number of columns (also called "branch lines" in some places)
157 */
158 int num_columns;
159 /*
160 * The number of columns in the new_columns array
161 */
162 int num_new_columns;
163 /*
164 * The number of entries in the mapping array
165 */
166 int mapping_size;
167 /*
168 * The column state before we output the current commit.
169 */
170 struct column *columns;
171 /*
172 * The new column state after we output the current commit.
173 * Only valid when state is GRAPH_COLLAPSING.
174 */
175 struct column *new_columns;
176 /*
177 * An array that tracks the current state of each
178 * character in the output line during state GRAPH_COLLAPSING.
179 * Each entry is -1 if this character is empty, or a non-negative
180 * integer if the character contains a branch line. The value of
181 * the integer indicates the target position for this branch line.
182 * (I.e., this array maps the current column positions to their
183 * desired positions.)
184 *
185 * The maximum capacity of this array is always
186 * sizeof(int) * 2 * column_capacity.
187 */
188 int *mapping;
189 /*
190 * A temporary array for computing the next mapping state
191 * while we are outputting a mapping line. This is stored as part
192 * of the git_graph simply so we don't have to allocate a new
193 * temporary array each time we have to output a collapsing line.
194 */
195 int *new_mapping;
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196 /*
197 * The current default column color being used. This is
198 * stored as an index into the array column_colors.
199 */
200 unsigned short default_column_color;
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201};
202
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203static struct strbuf *diff_output_prefix_callback(struct diff_options *opt, void *data)
204{
205 struct git_graph *graph = data;
206 static struct strbuf msgbuf = STRBUF_INIT;
207
208 assert(graph);
209
210 strbuf_reset(&msgbuf);
211 graph_padding_line(graph, &msgbuf);
212 return &msgbuf;
213}
214
7528f27d 215struct git_graph *graph_init(struct rev_info *opt)
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216{
217 struct git_graph *graph = xmalloc(sizeof(struct git_graph));
218 graph->commit = NULL;
7528f27d 219 graph->revs = opt;
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220 graph->num_parents = 0;
221 graph->expansion_row = 0;
222 graph->state = GRAPH_PADDING;
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223 graph->prev_state = GRAPH_PADDING;
224 graph->commit_index = 0;
225 graph->prev_commit_index = 0;
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226 graph->num_columns = 0;
227 graph->num_new_columns = 0;
228 graph->mapping_size = 0;
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229 /*
230 * Start the column color at the maximum value, since we'll
231 * always increment it for the first commit we output.
232 * This way we start at 0 for the first commit.
233 */
234 graph->default_column_color = COLUMN_COLORS_MAX - 1;
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235
236 /*
237 * Allocate a reasonably large default number of columns
238 * We'll automatically grow columns later if we need more room.
239 */
240 graph->column_capacity = 30;
241 graph->columns = xmalloc(sizeof(struct column) *
242 graph->column_capacity);
243 graph->new_columns = xmalloc(sizeof(struct column) *
244 graph->column_capacity);
245 graph->mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
246 graph->new_mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
247
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248 /*
249 * The diff output prefix callback, with this we can make
250 * all the diff output to align with the graph lines.
251 */
252 opt->diffopt.output_prefix = diff_output_prefix_callback;
253 opt->diffopt.output_prefix_data = graph;
254
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255 return graph;
256}
257
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258static void graph_update_state(struct git_graph *graph, enum graph_state s)
259{
260 graph->prev_state = graph->state;
261 graph->state = s;
262}
263
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264static void graph_ensure_capacity(struct git_graph *graph, int num_columns)
265{
266 if (graph->column_capacity >= num_columns)
267 return;
268
269 do {
270 graph->column_capacity *= 2;
271 } while (graph->column_capacity < num_columns);
272
273 graph->columns = xrealloc(graph->columns,
274 sizeof(struct column) *
275 graph->column_capacity);
276 graph->new_columns = xrealloc(graph->new_columns,
277 sizeof(struct column) *
278 graph->column_capacity);
279 graph->mapping = xrealloc(graph->mapping,
280 sizeof(int) * 2 * graph->column_capacity);
281 graph->new_mapping = xrealloc(graph->new_mapping,
282 sizeof(int) * 2 * graph->column_capacity);
283}
284
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285/*
286 * Returns 1 if the commit will be printed in the graph output,
287 * and 0 otherwise.
288 */
3c68d67b 289static int graph_is_interesting(struct git_graph *graph, struct commit *commit)
37a75abc 290{
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291 /*
292 * If revs->boundary is set, commits whose children have
293 * been shown are always interesting, even if they have the
294 * UNINTERESTING or TREESAME flags set.
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295 */
296 if (graph->revs && graph->revs->boundary) {
4603ec0f 297 if (commit->object.flags & CHILD_SHOWN)
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298 return 1;
299 }
300
37a75abc 301 /*
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302 * Otherwise, use get_commit_action() to see if this commit is
303 * interesting
37a75abc 304 */
beb5af43 305 return get_commit_action(graph->revs, commit) == commit_show;
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306}
307
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308static struct commit_list *next_interesting_parent(struct git_graph *graph,
309 struct commit_list *orig)
310{
311 struct commit_list *list;
312
313 /*
314 * If revs->first_parent_only is set, only the first
315 * parent is interesting. None of the others are.
316 */
317 if (graph->revs->first_parent_only)
318 return NULL;
319
320 /*
321 * Return the next interesting commit after orig
322 */
323 for (list = orig->next; list; list = list->next) {
324 if (graph_is_interesting(graph, list->item))
325 return list;
326 }
327
328 return NULL;
329}
330
331static struct commit_list *first_interesting_parent(struct git_graph *graph)
332{
333 struct commit_list *parents = graph->commit->parents;
334
335 /*
336 * If this commit has no parents, ignore it
337 */
338 if (!parents)
339 return NULL;
340
341 /*
342 * If the first parent is interesting, return it
343 */
344 if (graph_is_interesting(graph, parents->item))
345 return parents;
346
347 /*
348 * Otherwise, call next_interesting_parent() to get
349 * the next interesting parent
350 */
351 return next_interesting_parent(graph, parents);
352}
353
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354static unsigned short graph_get_current_column_color(const struct git_graph *graph)
355{
356 if (!DIFF_OPT_TST(&graph->revs->diffopt, COLOR_DIFF))
357 return COLUMN_COLORS_MAX;
358 return graph->default_column_color;
359}
360
361/*
362 * Update the graph's default column color.
363 */
364static void graph_increment_column_color(struct git_graph *graph)
365{
366 graph->default_column_color = (graph->default_column_color + 1) %
367 COLUMN_COLORS_MAX;
368}
369
370static unsigned short graph_find_commit_color(const struct git_graph *graph,
371 const struct commit *commit)
372{
373 int i;
374 for (i = 0; i < graph->num_columns; i++) {
375 if (graph->columns[i].commit == commit)
376 return graph->columns[i].color;
377 }
378 return graph_get_current_column_color(graph);
379}
380
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381static void graph_insert_into_new_columns(struct git_graph *graph,
382 struct commit *commit,
383 int *mapping_index)
384{
385 int i;
386
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387 /*
388 * If the commit is already in the new_columns list, we don't need to
389 * add it. Just update the mapping correctly.
390 */
391 for (i = 0; i < graph->num_new_columns; i++) {
392 if (graph->new_columns[i].commit == commit) {
393 graph->mapping[*mapping_index] = i;
394 *mapping_index += 2;
395 return;
396 }
397 }
398
399 /*
400 * This commit isn't already in new_columns. Add it.
401 */
402 graph->new_columns[graph->num_new_columns].commit = commit;
427fc5b8 403 graph->new_columns[graph->num_new_columns].color = graph_find_commit_color(graph, commit);
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404 graph->mapping[*mapping_index] = graph->num_new_columns;
405 *mapping_index += 2;
406 graph->num_new_columns++;
407}
408
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409static void graph_update_width(struct git_graph *graph,
410 int is_commit_in_existing_columns)
411{
412 /*
413 * Compute the width needed to display the graph for this commit.
414 * This is the maximum width needed for any row. All other rows
415 * will be padded to this width.
416 *
417 * Compute the number of columns in the widest row:
418 * Count each existing column (graph->num_columns), and each new
419 * column added by this commit.
420 */
421 int max_cols = graph->num_columns + graph->num_parents;
422
423 /*
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424 * Even if the current commit has no parents to be printed, it
425 * still takes up a column for itself.
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426 */
427 if (graph->num_parents < 1)
428 max_cols++;
429
430 /*
431 * We added a column for the the current commit as part of
432 * graph->num_parents. If the current commit was already in
433 * graph->columns, then we have double counted it.
434 */
435 if (is_commit_in_existing_columns)
436 max_cols--;
437
438 /*
439 * Each column takes up 2 spaces
440 */
441 graph->width = max_cols * 2;
442}
443
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444static void graph_update_columns(struct git_graph *graph)
445{
446 struct commit_list *parent;
447 struct column *tmp_columns;
448 int max_new_columns;
449 int mapping_idx;
0724cb86 450 int i, seen_this, is_commit_in_columns;
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451
452 /*
453 * Swap graph->columns with graph->new_columns
454 * graph->columns contains the state for the previous commit,
455 * and new_columns now contains the state for our commit.
456 *
457 * We'll re-use the old columns array as storage to compute the new
458 * columns list for the commit after this one.
459 */
460 tmp_columns = graph->columns;
461 graph->columns = graph->new_columns;
462 graph->num_columns = graph->num_new_columns;
463
464 graph->new_columns = tmp_columns;
465 graph->num_new_columns = 0;
466
467 /*
468 * Now update new_columns and mapping with the information for the
469 * commit after this one.
470 *
471 * First, make sure we have enough room. At most, there will
472 * be graph->num_columns + graph->num_parents columns for the next
473 * commit.
474 */
475 max_new_columns = graph->num_columns + graph->num_parents;
476 graph_ensure_capacity(graph, max_new_columns);
477
478 /*
479 * Clear out graph->mapping
480 */
481 graph->mapping_size = 2 * max_new_columns;
482 for (i = 0; i < graph->mapping_size; i++)
483 graph->mapping[i] = -1;
484
485 /*
486 * Populate graph->new_columns and graph->mapping
487 *
488 * Some of the parents of this commit may already be in
489 * graph->columns. If so, graph->new_columns should only contain a
490 * single entry for each such commit. graph->mapping should
491 * contain information about where each current branch line is
492 * supposed to end up after the collapsing is performed.
493 */
494 seen_this = 0;
495 mapping_idx = 0;
0724cb86 496 is_commit_in_columns = 1;
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497 for (i = 0; i <= graph->num_columns; i++) {
498 struct commit *col_commit;
499 if (i == graph->num_columns) {
500 if (seen_this)
501 break;
0724cb86 502 is_commit_in_columns = 0;
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503 col_commit = graph->commit;
504 } else {
505 col_commit = graph->columns[i].commit;
506 }
507
508 if (col_commit == graph->commit) {
37a75abc 509 int old_mapping_idx = mapping_idx;
c12172d2 510 seen_this = 1;
3395908e 511 graph->commit_index = i;
a0ebe573 512 for (parent = first_interesting_parent(graph);
c12172d2 513 parent;
a0ebe573 514 parent = next_interesting_parent(graph, parent)) {
427fc5b8 515 /*
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516 * If this is a merge, or the start of a new
517 * childless column, increment the current
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518 * color.
519 */
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520 if (graph->num_parents > 1 ||
521 !is_commit_in_columns) {
427fc5b8 522 graph_increment_column_color(graph);
91e50b2c 523 }
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524 graph_insert_into_new_columns(graph,
525 parent->item,
526 &mapping_idx);
527 }
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528 /*
529 * We always need to increment mapping_idx by at
530 * least 2, even if it has no interesting parents.
531 * The current commit always takes up at least 2
532 * spaces.
533 */
534 if (mapping_idx == old_mapping_idx)
535 mapping_idx += 2;
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536 } else {
537 graph_insert_into_new_columns(graph, col_commit,
538 &mapping_idx);
539 }
540 }
541
542 /*
543 * Shrink mapping_size to be the minimum necessary
544 */
545 while (graph->mapping_size > 1 &&
546 graph->mapping[graph->mapping_size - 1] < 0)
547 graph->mapping_size--;
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548
549 /*
550 * Compute graph->width for this commit
551 */
552 graph_update_width(graph, is_commit_in_columns);
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553}
554
555void graph_update(struct git_graph *graph, struct commit *commit)
556{
557 struct commit_list *parent;
558
559 /*
560 * Set the new commit
561 */
562 graph->commit = commit;
563
564 /*
37a75abc 565 * Count how many interesting parents this commit has
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566 */
567 graph->num_parents = 0;
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568 for (parent = first_interesting_parent(graph);
569 parent;
570 parent = next_interesting_parent(graph, parent))
571 {
572 graph->num_parents++;
37a75abc 573 }
c12172d2 574
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575 /*
576 * Store the old commit_index in prev_commit_index.
577 * graph_update_columns() will update graph->commit_index for this
578 * commit.
579 */
580 graph->prev_commit_index = graph->commit_index;
581
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582 /*
583 * Call graph_update_columns() to update
584 * columns, new_columns, and mapping.
585 */
586 graph_update_columns(graph);
587
588 graph->expansion_row = 0;
589
590 /*
591 * Update graph->state.
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592 * Note that we don't call graph_update_state() here, since
593 * we don't want to update graph->prev_state. No line for
594 * graph->state was ever printed.
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595 *
596 * If the previous commit didn't get to the GRAPH_PADDING state,
597 * it never finished its output. Goto GRAPH_SKIP, to print out
598 * a line to indicate that portion of the graph is missing.
599 *
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600 * If there are 3 or more parents, we may need to print extra rows
601 * before the commit, to expand the branch lines around it and make
602 * room for it. We need to do this only if there is a branch row
603 * (or more) to the right of this commit.
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604 *
605 * If there are less than 3 parents, we can immediately print the
606 * commit line.
607 */
608 if (graph->state != GRAPH_PADDING)
609 graph->state = GRAPH_SKIP;
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610 else if (graph->num_parents >= 3 &&
611 graph->commit_index < (graph->num_columns - 1))
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612 graph->state = GRAPH_PRE_COMMIT;
613 else
614 graph->state = GRAPH_COMMIT;
615}
616
617static int graph_is_mapping_correct(struct git_graph *graph)
618{
619 int i;
620
621 /*
622 * The mapping is up to date if each entry is at its target,
623 * or is 1 greater than its target.
624 * (If it is 1 greater than the target, '/' will be printed, so it
625 * will look correct on the next row.)
626 */
627 for (i = 0; i < graph->mapping_size; i++) {
628 int target = graph->mapping[i];
629 if (target < 0)
630 continue;
631 if (target == (i / 2))
632 continue;
633 return 0;
634 }
635
636 return 1;
637}
638
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639static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb,
640 int chars_written)
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641{
642 /*
643 * Add additional spaces to the end of the strbuf, so that all
644 * lines for a particular commit have the same width.
645 *
646 * This way, fields printed to the right of the graph will remain
647 * aligned for the entire commit.
c12172d2 648 */
0724cb86 649 int extra;
427fc5b8 650 if (chars_written >= graph->width)
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651 return;
652
427fc5b8 653 extra = graph->width - chars_written;
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654 strbuf_addf(sb, "%*s", (int) extra, "");
655}
656
657static void graph_output_padding_line(struct git_graph *graph,
658 struct strbuf *sb)
659{
660 int i;
661
662 /*
663 * We could conceivable be called with a NULL commit
664 * if our caller has a bug, and invokes graph_next_line()
665 * immediately after graph_init(), without first calling
666 * graph_update(). Return without outputting anything in this
667 * case.
668 */
669 if (!graph->commit)
670 return;
671
672 /*
673 * Output a padding row, that leaves all branch lines unchanged
674 */
675 for (i = 0; i < graph->num_new_columns; i++) {
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676 strbuf_write_column(sb, &graph->new_columns[i], '|');
677 strbuf_addch(sb, ' ');
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678 }
679
427fc5b8 680 graph_pad_horizontally(graph, sb, graph->num_new_columns * 2);
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681}
682
683static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
684{
685 /*
686 * Output an ellipsis to indicate that a portion
687 * of the graph is missing.
688 */
689 strbuf_addstr(sb, "...");
427fc5b8 690 graph_pad_horizontally(graph, sb, 3);
c12172d2 691
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692 if (graph->num_parents >= 3 &&
693 graph->commit_index < (graph->num_columns - 1))
3395908e 694 graph_update_state(graph, GRAPH_PRE_COMMIT);
c12172d2 695 else
3395908e 696 graph_update_state(graph, GRAPH_COMMIT);
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697}
698
699static void graph_output_pre_commit_line(struct git_graph *graph,
700 struct strbuf *sb)
701{
702 int num_expansion_rows;
703 int i, seen_this;
427fc5b8 704 int chars_written;
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705
706 /*
707 * This function formats a row that increases the space around a commit
708 * with multiple parents, to make room for it. It should only be
709 * called when there are 3 or more parents.
710 *
711 * We need 2 extra rows for every parent over 2.
712 */
713 assert(graph->num_parents >= 3);
714 num_expansion_rows = (graph->num_parents - 2) * 2;
715
716 /*
717 * graph->expansion_row tracks the current expansion row we are on.
718 * It should be in the range [0, num_expansion_rows - 1]
719 */
720 assert(0 <= graph->expansion_row &&
721 graph->expansion_row < num_expansion_rows);
722
723 /*
724 * Output the row
725 */
726 seen_this = 0;
427fc5b8 727 chars_written = 0;
c12172d2
AS
728 for (i = 0; i < graph->num_columns; i++) {
729 struct column *col = &graph->columns[i];
730 if (col->commit == graph->commit) {
731 seen_this = 1;
427fc5b8 732 strbuf_write_column(sb, col, '|');
36a31fea
AC
733 strbuf_addf(sb, "%*s", graph->expansion_row, "");
734 chars_written += 1 + graph->expansion_row;
3395908e
AS
735 } else if (seen_this && (graph->expansion_row == 0)) {
736 /*
737 * This is the first line of the pre-commit output.
738 * If the previous commit was a merge commit and
739 * ended in the GRAPH_POST_MERGE state, all branch
740 * lines after graph->prev_commit_index were
741 * printed as "\" on the previous line. Continue
742 * to print them as "\" on this line. Otherwise,
743 * print the branch lines as "|".
744 */
745 if (graph->prev_state == GRAPH_POST_MERGE &&
746 graph->prev_commit_index < i)
427fc5b8 747 strbuf_write_column(sb, col, '\\');
3395908e 748 else
427fc5b8
AC
749 strbuf_write_column(sb, col, '|');
750 chars_written++;
3395908e 751 } else if (seen_this && (graph->expansion_row > 0)) {
427fc5b8
AC
752 strbuf_write_column(sb, col, '\\');
753 chars_written++;
c12172d2 754 } else {
427fc5b8
AC
755 strbuf_write_column(sb, col, '|');
756 chars_written++;
c12172d2 757 }
427fc5b8
AC
758 strbuf_addch(sb, ' ');
759 chars_written++;
c12172d2
AS
760 }
761
427fc5b8 762 graph_pad_horizontally(graph, sb, chars_written);
c12172d2
AS
763
764 /*
765 * Increment graph->expansion_row,
766 * and move to state GRAPH_COMMIT if necessary
767 */
768 graph->expansion_row++;
769 if (graph->expansion_row >= num_expansion_rows)
3395908e 770 graph_update_state(graph, GRAPH_COMMIT);
c12172d2
AS
771}
772
3c68d67b
AS
773static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
774{
775 /*
776 * For boundary commits, print 'o'
777 * (We should only see boundary commits when revs->boundary is set.)
778 */
779 if (graph->commit->object.flags & BOUNDARY) {
780 assert(graph->revs->boundary);
781 strbuf_addch(sb, 'o');
782 return;
783 }
784
785 /*
786 * If revs->left_right is set, print '<' for commits that
787 * come from the left side, and '>' for commits from the right
788 * side.
789 */
790 if (graph->revs && graph->revs->left_right) {
791 if (graph->commit->object.flags & SYMMETRIC_LEFT)
792 strbuf_addch(sb, '<');
793 else
794 strbuf_addch(sb, '>');
795 return;
796 }
797
3c68d67b
AS
798 /*
799 * Print '*' in all other cases
800 */
801 strbuf_addch(sb, '*');
802}
803
427fc5b8
AC
804/*
805 * Draw an octopus merge and return the number of characters written.
806 */
807static int graph_draw_octopus_merge(struct git_graph *graph,
808 struct strbuf *sb)
809{
810 /*
811 * Here dashless_commits represents the number of parents
812 * which don't need to have dashes (because their edges fit
813 * neatly under the commit).
814 */
815 const int dashless_commits = 2;
816 int col_num, i;
817 int num_dashes =
818 ((graph->num_parents - dashless_commits) * 2) - 1;
819 for (i = 0; i < num_dashes; i++) {
820 col_num = (i / 2) + dashless_commits;
821 strbuf_write_column(sb, &graph->new_columns[col_num], '-');
822 }
823 col_num = (i / 2) + dashless_commits;
824 strbuf_write_column(sb, &graph->new_columns[col_num], '.');
825 return num_dashes + 1;
826}
827
064bfbde 828static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
c12172d2
AS
829{
830 int seen_this = 0;
427fc5b8 831 int i, chars_written;
c12172d2
AS
832
833 /*
834 * Output the row containing this commit
835 * Iterate up to and including graph->num_columns,
836 * since the current commit may not be in any of the existing
837 * columns. (This happens when the current commit doesn't have any
838 * children that we have already processed.)
839 */
840 seen_this = 0;
427fc5b8 841 chars_written = 0;
c12172d2 842 for (i = 0; i <= graph->num_columns; i++) {
427fc5b8 843 struct column *col = &graph->columns[i];
c12172d2
AS
844 struct commit *col_commit;
845 if (i == graph->num_columns) {
846 if (seen_this)
847 break;
848 col_commit = graph->commit;
849 } else {
850 col_commit = graph->columns[i].commit;
851 }
852
853 if (col_commit == graph->commit) {
854 seen_this = 1;
3c68d67b 855 graph_output_commit_char(graph, sb);
427fc5b8 856 chars_written++;
c12172d2 857
a6c1a382 858 if (graph->num_parents > 2)
427fc5b8
AC
859 chars_written += graph_draw_octopus_merge(graph,
860 sb);
3395908e 861 } else if (seen_this && (graph->num_parents > 2)) {
427fc5b8
AC
862 strbuf_write_column(sb, col, '\\');
863 chars_written++;
3395908e
AS
864 } else if (seen_this && (graph->num_parents == 2)) {
865 /*
866 * This is a 2-way merge commit.
867 * There is no GRAPH_PRE_COMMIT stage for 2-way
868 * merges, so this is the first line of output
869 * for this commit. Check to see what the previous
870 * line of output was.
871 *
872 * If it was GRAPH_POST_MERGE, the branch line
873 * coming into this commit may have been '\',
874 * and not '|' or '/'. If so, output the branch
875 * line as '\' on this line, instead of '|'. This
876 * makes the output look nicer.
877 */
878 if (graph->prev_state == GRAPH_POST_MERGE &&
879 graph->prev_commit_index < i)
427fc5b8 880 strbuf_write_column(sb, col, '\\');
3395908e 881 else
427fc5b8
AC
882 strbuf_write_column(sb, col, '|');
883 chars_written++;
c12172d2 884 } else {
427fc5b8
AC
885 strbuf_write_column(sb, col, '|');
886 chars_written++;
c12172d2 887 }
427fc5b8
AC
888 strbuf_addch(sb, ' ');
889 chars_written++;
c12172d2
AS
890 }
891
427fc5b8 892 graph_pad_horizontally(graph, sb, chars_written);
c12172d2
AS
893
894 /*
895 * Update graph->state
896 */
897 if (graph->num_parents > 1)
3395908e 898 graph_update_state(graph, GRAPH_POST_MERGE);
c12172d2 899 else if (graph_is_mapping_correct(graph))
3395908e 900 graph_update_state(graph, GRAPH_PADDING);
c12172d2 901 else
3395908e 902 graph_update_state(graph, GRAPH_COLLAPSING);
c12172d2
AS
903}
904
427fc5b8
AC
905static struct column *find_new_column_by_commit(struct git_graph *graph,
906 struct commit *commit)
907{
908 int i;
909 for (i = 0; i < graph->num_new_columns; i++) {
910 if (graph->new_columns[i].commit == commit)
911 return &graph->new_columns[i];
912 }
67da52be 913 return NULL;
427fc5b8
AC
914}
915
064bfbde 916static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
c12172d2
AS
917{
918 int seen_this = 0;
427fc5b8 919 int i, j, chars_written;
c12172d2
AS
920
921 /*
922 * Output the post-merge row
923 */
427fc5b8 924 chars_written = 0;
c12172d2 925 for (i = 0; i <= graph->num_columns; i++) {
427fc5b8 926 struct column *col = &graph->columns[i];
c12172d2
AS
927 struct commit *col_commit;
928 if (i == graph->num_columns) {
929 if (seen_this)
930 break;
931 col_commit = graph->commit;
932 } else {
427fc5b8 933 col_commit = col->commit;
c12172d2
AS
934 }
935
936 if (col_commit == graph->commit) {
427fc5b8
AC
937 /*
938 * Since the current commit is a merge find
939 * the columns for the parent commits in
940 * new_columns and use those to format the
941 * edges.
942 */
943 struct commit_list *parents = NULL;
944 struct column *par_column;
c12172d2 945 seen_this = 1;
427fc5b8
AC
946 parents = first_interesting_parent(graph);
947 assert(parents);
948 par_column = find_new_column_by_commit(graph, parents->item);
949 assert(par_column);
950
951 strbuf_write_column(sb, par_column, '|');
952 chars_written++;
953 for (j = 0; j < graph->num_parents - 1; j++) {
954 parents = next_interesting_parent(graph, parents);
955 assert(parents);
956 par_column = find_new_column_by_commit(graph, parents->item);
957 assert(par_column);
958 strbuf_write_column(sb, par_column, '\\');
959 strbuf_addch(sb, ' ');
960 }
961 chars_written += j * 2;
3395908e 962 } else if (seen_this) {
427fc5b8
AC
963 strbuf_write_column(sb, col, '\\');
964 strbuf_addch(sb, ' ');
965 chars_written += 2;
c12172d2 966 } else {
427fc5b8
AC
967 strbuf_write_column(sb, col, '|');
968 strbuf_addch(sb, ' ');
969 chars_written += 2;
c12172d2
AS
970 }
971 }
972
427fc5b8 973 graph_pad_horizontally(graph, sb, chars_written);
c12172d2
AS
974
975 /*
976 * Update graph->state
977 */
978 if (graph_is_mapping_correct(graph))
3395908e 979 graph_update_state(graph, GRAPH_PADDING);
c12172d2 980 else
3395908e 981 graph_update_state(graph, GRAPH_COLLAPSING);
c12172d2
AS
982}
983
064bfbde 984static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb)
c12172d2
AS
985{
986 int i;
987 int *tmp_mapping;
eaf158f8
AC
988 short used_horizontal = 0;
989 int horizontal_edge = -1;
990 int horizontal_edge_target = -1;
c12172d2
AS
991
992 /*
993 * Clear out the new_mapping array
994 */
995 for (i = 0; i < graph->mapping_size; i++)
996 graph->new_mapping[i] = -1;
997
998 for (i = 0; i < graph->mapping_size; i++) {
999 int target = graph->mapping[i];
1000 if (target < 0)
1001 continue;
1002
1003 /*
1004 * Since update_columns() always inserts the leftmost
1005 * column first, each branch's target location should
1006 * always be either its current location or to the left of
1007 * its current location.
1008 *
1009 * We never have to move branches to the right. This makes
1010 * the graph much more legible, since whenever branches
1011 * cross, only one is moving directions.
1012 */
1013 assert(target * 2 <= i);
1014
1015 if (target * 2 == i) {
1016 /*
1017 * This column is already in the
1018 * correct place
1019 */
1020 assert(graph->new_mapping[i] == -1);
1021 graph->new_mapping[i] = target;
1022 } else if (graph->new_mapping[i - 1] < 0) {
1023 /*
1024 * Nothing is to the left.
1025 * Move to the left by one
1026 */
1027 graph->new_mapping[i - 1] = target;
eaf158f8
AC
1028 /*
1029 * If there isn't already an edge moving horizontally
1030 * select this one.
1031 */
1032 if (horizontal_edge == -1) {
1033 int j;
1034 horizontal_edge = i;
1035 horizontal_edge_target = target;
1036 /*
1037 * The variable target is the index of the graph
1038 * column, and therefore target*2+3 is the
1039 * actual screen column of the first horizontal
1040 * line.
1041 */
1042 for (j = (target * 2)+3; j < (i - 2); j += 2)
1043 graph->new_mapping[j] = target;
1044 }
c12172d2
AS
1045 } else if (graph->new_mapping[i - 1] == target) {
1046 /*
1047 * There is a branch line to our left
1048 * already, and it is our target. We
1049 * combine with this line, since we share
1050 * the same parent commit.
1051 *
1052 * We don't have to add anything to the
1053 * output or new_mapping, since the
1054 * existing branch line has already taken
1055 * care of it.
1056 */
1057 } else {
1058 /*
1059 * There is a branch line to our left,
1060 * but it isn't our target. We need to
1061 * cross over it.
1062 *
1063 * The space just to the left of this
1064 * branch should always be empty.
eaf158f8
AC
1065 *
1066 * The branch to the left of that space
1067 * should be our eventual target.
c12172d2
AS
1068 */
1069 assert(graph->new_mapping[i - 1] > target);
1070 assert(graph->new_mapping[i - 2] < 0);
eaf158f8 1071 assert(graph->new_mapping[i - 3] == target);
c12172d2 1072 graph->new_mapping[i - 2] = target;
eaf158f8
AC
1073 /*
1074 * Mark this branch as the horizontal edge to
1075 * prevent any other edges from moving
1076 * horizontally.
1077 */
1078 if (horizontal_edge == -1)
1079 horizontal_edge = i;
c12172d2
AS
1080 }
1081 }
1082
1083 /*
1084 * The new mapping may be 1 smaller than the old mapping
1085 */
1086 if (graph->new_mapping[graph->mapping_size - 1] < 0)
1087 graph->mapping_size--;
1088
1089 /*
1090 * Output out a line based on the new mapping info
1091 */
1092 for (i = 0; i < graph->mapping_size; i++) {
1093 int target = graph->new_mapping[i];
1094 if (target < 0)
1095 strbuf_addch(sb, ' ');
1096 else if (target * 2 == i)
427fc5b8 1097 strbuf_write_column(sb, &graph->new_columns[target], '|');
eaf158f8
AC
1098 else if (target == horizontal_edge_target &&
1099 i != horizontal_edge - 1) {
1100 /*
1101 * Set the mappings for all but the
1102 * first segment to -1 so that they
1103 * won't continue into the next line.
1104 */
1105 if (i != (target * 2)+3)
1106 graph->new_mapping[i] = -1;
1107 used_horizontal = 1;
1108 strbuf_write_column(sb, &graph->new_columns[target], '_');
1109 } else {
1110 if (used_horizontal && i < horizontal_edge)
1111 graph->new_mapping[i] = -1;
427fc5b8 1112 strbuf_write_column(sb, &graph->new_columns[target], '/');
eaf158f8
AC
1113
1114 }
c12172d2
AS
1115 }
1116
427fc5b8 1117 graph_pad_horizontally(graph, sb, graph->mapping_size);
c12172d2
AS
1118
1119 /*
1120 * Swap mapping and new_mapping
1121 */
1122 tmp_mapping = graph->mapping;
1123 graph->mapping = graph->new_mapping;
1124 graph->new_mapping = tmp_mapping;
1125
1126 /*
1127 * If graph->mapping indicates that all of the branch lines
1128 * are already in the correct positions, we are done.
1129 * Otherwise, we need to collapse some branch lines together.
1130 */
1131 if (graph_is_mapping_correct(graph))
3395908e 1132 graph_update_state(graph, GRAPH_PADDING);
c12172d2
AS
1133}
1134
6bdc17d9 1135int graph_next_line(struct git_graph *graph, struct strbuf *sb)
c12172d2
AS
1136{
1137 switch (graph->state) {
1138 case GRAPH_PADDING:
1139 graph_output_padding_line(graph, sb);
1140 return 0;
1141 case GRAPH_SKIP:
1142 graph_output_skip_line(graph, sb);
1143 return 0;
1144 case GRAPH_PRE_COMMIT:
1145 graph_output_pre_commit_line(graph, sb);
1146 return 0;
1147 case GRAPH_COMMIT:
1148 graph_output_commit_line(graph, sb);
1149 return 1;
1150 case GRAPH_POST_MERGE:
1151 graph_output_post_merge_line(graph, sb);
1152 return 0;
1153 case GRAPH_COLLAPSING:
1154 graph_output_collapsing_line(graph, sb);
1155 return 0;
1156 }
1157
1158 assert(0);
1159 return 0;
1160}
1161
064bfbde 1162static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
c12172d2
AS
1163{
1164 int i, j;
1165
1166 if (graph->state != GRAPH_COMMIT) {
1167 graph_next_line(graph, sb);
1168 return;
1169 }
1170
1171 /*
1172 * Output the row containing this commit
1173 * Iterate up to and including graph->num_columns,
1174 * since the current commit may not be in any of the existing
1175 * columns. (This happens when the current commit doesn't have any
1176 * children that we have already processed.)
1177 */
1178 for (i = 0; i < graph->num_columns; i++) {
427fc5b8
AC
1179 struct column *col = &graph->columns[i];
1180 struct commit *col_commit = col->commit;
c12172d2 1181 if (col_commit == graph->commit) {
427fc5b8 1182 strbuf_write_column(sb, col, '|');
c12172d2
AS
1183
1184 if (graph->num_parents < 3)
1185 strbuf_addch(sb, ' ');
1186 else {
1187 int num_spaces = ((graph->num_parents - 2) * 2);
1188 for (j = 0; j < num_spaces; j++)
1189 strbuf_addch(sb, ' ');
1190 }
1191 } else {
427fc5b8
AC
1192 strbuf_write_column(sb, col, '|');
1193 strbuf_addch(sb, ' ');
c12172d2
AS
1194 }
1195 }
1196
427fc5b8 1197 graph_pad_horizontally(graph, sb, graph->num_columns);
3395908e
AS
1198
1199 /*
1200 * Update graph->prev_state since we have output a padding line
1201 */
1202 graph->prev_state = GRAPH_PADDING;
c12172d2
AS
1203}
1204
1205int graph_is_commit_finished(struct git_graph const *graph)
1206{
1207 return (graph->state == GRAPH_PADDING);
1208}
1209
1210void graph_show_commit(struct git_graph *graph)
1211{
f285a2d7 1212 struct strbuf msgbuf = STRBUF_INIT;
c12172d2
AS
1213 int shown_commit_line = 0;
1214
1215 if (!graph)
1216 return;
1217
c12172d2
AS
1218 while (!shown_commit_line) {
1219 shown_commit_line = graph_next_line(graph, &msgbuf);
1220 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1221 if (!shown_commit_line)
1222 putchar('\n');
1223 strbuf_setlen(&msgbuf, 0);
1224 }
1225
1226 strbuf_release(&msgbuf);
1227}
1228
1229void graph_show_oneline(struct git_graph *graph)
1230{
f285a2d7 1231 struct strbuf msgbuf = STRBUF_INIT;
c12172d2
AS
1232
1233 if (!graph)
1234 return;
1235
c12172d2
AS
1236 graph_next_line(graph, &msgbuf);
1237 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1238 strbuf_release(&msgbuf);
1239}
1240
1241void graph_show_padding(struct git_graph *graph)
1242{
f285a2d7 1243 struct strbuf msgbuf = STRBUF_INIT;
c12172d2
AS
1244
1245 if (!graph)
1246 return;
1247
c12172d2
AS
1248 graph_padding_line(graph, &msgbuf);
1249 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1250 strbuf_release(&msgbuf);
1251}
1252
1253int graph_show_remainder(struct git_graph *graph)
1254{
f285a2d7 1255 struct strbuf msgbuf = STRBUF_INIT;
c12172d2
AS
1256 int shown = 0;
1257
1258 if (!graph)
1259 return 0;
1260
1261 if (graph_is_commit_finished(graph))
1262 return 0;
1263
c12172d2
AS
1264 for (;;) {
1265 graph_next_line(graph, &msgbuf);
1266 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
1267 strbuf_setlen(&msgbuf, 0);
1268 shown = 1;
1269
1270 if (!graph_is_commit_finished(graph))
1271 putchar('\n');
1272 else
1273 break;
1274 }
1275 strbuf_release(&msgbuf);
1276
1277 return shown;
1278}
1279
1280
064bfbde 1281static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb)
c12172d2
AS
1282{
1283 char *p;
1284
1285 if (!graph) {
1286 fwrite(sb->buf, sizeof(char), sb->len, stdout);
1287 return;
1288 }
1289
1290 /*
1291 * Print the strbuf line by line,
1292 * and display the graph info before each line but the first.
1293 */
1294 p = sb->buf;
1295 while (p) {
1296 size_t len;
1297 char *next_p = strchr(p, '\n');
1298 if (next_p) {
1299 next_p++;
1300 len = next_p - p;
1301 } else {
1302 len = (sb->buf + sb->len) - p;
1303 }
1304 fwrite(p, sizeof(char), len, stdout);
1305 if (next_p && *next_p != '\0')
1306 graph_show_oneline(graph);
1307 p = next_p;
1308 }
1309}
1310
1311void graph_show_commit_msg(struct git_graph *graph,
1312 struct strbuf const *sb)
1313{
1314 int newline_terminated;
1315
1316 if (!graph) {
1317 /*
1318 * If there's no graph, just print the message buffer.
1319 *
1320 * The message buffer for CMIT_FMT_ONELINE and
1321 * CMIT_FMT_USERFORMAT are already missing a terminating
1322 * newline. All of the other formats should have it.
1323 */
1324 fwrite(sb->buf, sizeof(char), sb->len, stdout);
1325 return;
1326 }
1327
1328 newline_terminated = (sb->len && sb->buf[sb->len - 1] == '\n');
1329
1330 /*
1331 * Show the commit message
1332 */
1333 graph_show_strbuf(graph, sb);
1334
1335 /*
1336 * If there is more output needed for this commit, show it now
1337 */
1338 if (!graph_is_commit_finished(graph)) {
1339 /*
1340 * If sb doesn't have a terminating newline, print one now,
1341 * so we can start the remainder of the graph output on a
1342 * new line.
1343 */
1344 if (!newline_terminated)
1345 putchar('\n');
1346
1347 graph_show_remainder(graph);
1348
1349 /*
1350 * If sb ends with a newline, our output should too.
1351 */
1352 if (newline_terminated)
1353 putchar('\n');
1354 }
1355}