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[git/git.git] / graph.c
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1#include "cache.h"
2#include "commit.h"
427fc5b8 3#include "color.h"
c12172d2 4#include "graph.h"
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5#include "revision.h"
6
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7/* Internal API */
8
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9/*
10 * Output a padding line in the graph.
11 * This is similar to graph_next_line(). However, it is guaranteed to
12 * never print the current commit line. Instead, if the commit line is
13 * next, it will simply output a line of vertical padding, extending the
14 * branch lines downwards, but leaving them otherwise unchanged.
15 */
16static void graph_padding_line(struct git_graph *graph, struct strbuf *sb);
17
18/*
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19 * Print a strbuf. If the graph is non-NULL, all lines but the first will be
20 * prefixed with the graph output.
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21 *
22 * If the strbuf ends with a newline, the output will end after this
23 * newline. A new graph line will not be printed after the final newline.
24 * If the strbuf is empty, no output will be printed.
25 *
3ea3c215 26 * Since the first line will not include the graph output, the caller is
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27 * responsible for printing this line's graph (perhaps via
28 * graph_show_commit() or graph_show_oneline()) before calling
29 * graph_show_strbuf().
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30 *
31 * Note that unlike some other graph display functions, you must pass the file
32 * handle directly. It is assumed that this is the same file handle as the
33 * file specified by the graph diff options. This is necessary so that
34 * graph_show_strbuf can be called even with a NULL graph.
064bfbde 35 */
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36static void graph_show_strbuf(struct git_graph *graph,
37 FILE *file,
38 struct strbuf const *sb);
064bfbde 39
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40/*
41 * TODO:
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42 * - Limit the number of columns, similar to the way gitk does.
43 * If we reach more than a specified number of columns, omit
44 * sections of some columns.
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45 */
46
47struct column {
48 /*
49 * The parent commit of this column.
50 */
51 struct commit *commit;
52 /*
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53 * The color to (optionally) print this column in. This is an
54 * index into column_colors.
c12172d2 55 */
427fc5b8 56 unsigned short color;
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57};
58
59enum graph_state {
60 GRAPH_PADDING,
61 GRAPH_SKIP,
62 GRAPH_PRE_COMMIT,
63 GRAPH_COMMIT,
64 GRAPH_POST_MERGE,
65 GRAPH_COLLAPSING
66};
67
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68static void graph_show_line_prefix(const struct diff_options *diffopt)
69{
70 if (!diffopt || !diffopt->line_prefix)
71 return;
72
73 fwrite(diffopt->line_prefix,
74 sizeof(char),
75 diffopt->line_prefix_length,
76 diffopt->file);
77}
78
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79static const char **column_colors;
80static unsigned short column_colors_max;
81
ac751a0b 82void graph_set_column_colors(const char **colors, unsigned short colors_max)
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83{
84 column_colors = colors;
85 column_colors_max = colors_max;
86}
87
88static const char *column_get_color_code(unsigned short color)
427fc5b8 89{
1e3d4119 90 return column_colors[color];
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91}
92
93static void strbuf_write_column(struct strbuf *sb, const struct column *c,
94 char col_char)
95{
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96 if (c->color < column_colors_max)
97 strbuf_addstr(sb, column_get_color_code(c->color));
427fc5b8 98 strbuf_addch(sb, col_char);
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99 if (c->color < column_colors_max)
100 strbuf_addstr(sb, column_get_color_code(column_colors_max));
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101}
102
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103struct git_graph {
104 /*
105 * The commit currently being processed
106 */
107 struct commit *commit;
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108 /* The rev-info used for the current traversal */
109 struct rev_info *revs;
c12172d2 110 /*
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111 * The number of interesting parents that this commit has.
112 *
113 * Note that this is not the same as the actual number of parents.
114 * This count excludes parents that won't be printed in the graph
115 * output, as determined by graph_is_interesting().
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116 */
117 int num_parents;
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118 /*
119 * The width of the graph output for this commit.
120 * All rows for this commit are padded to this width, so that
121 * messages printed after the graph output are aligned.
122 */
123 int width;
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124 /*
125 * The next expansion row to print
126 * when state is GRAPH_PRE_COMMIT
127 */
128 int expansion_row;
129 /*
130 * The current output state.
131 * This tells us what kind of line graph_next_line() should output.
132 */
133 enum graph_state state;
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134 /*
135 * The output state for the previous line of output.
136 * This is primarily used to determine how the first merge line
137 * should appear, based on the last line of the previous commit.
138 */
139 enum graph_state prev_state;
140 /*
141 * The index of the column that refers to this commit.
142 *
143 * If none of the incoming columns refer to this commit,
144 * this will be equal to num_columns.
145 */
146 int commit_index;
147 /*
148 * The commit_index for the previously displayed commit.
149 *
150 * This is used to determine how the first line of a merge
151 * graph output should appear, based on the last line of the
152 * previous commit.
153 */
154 int prev_commit_index;
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155 /*
156 * The maximum number of columns that can be stored in the columns
157 * and new_columns arrays. This is also half the number of entries
158 * that can be stored in the mapping and new_mapping arrays.
159 */
160 int column_capacity;
161 /*
162 * The number of columns (also called "branch lines" in some places)
163 */
164 int num_columns;
165 /*
166 * The number of columns in the new_columns array
167 */
168 int num_new_columns;
169 /*
170 * The number of entries in the mapping array
171 */
172 int mapping_size;
173 /*
174 * The column state before we output the current commit.
175 */
176 struct column *columns;
177 /*
178 * The new column state after we output the current commit.
179 * Only valid when state is GRAPH_COLLAPSING.
180 */
181 struct column *new_columns;
182 /*
183 * An array that tracks the current state of each
184 * character in the output line during state GRAPH_COLLAPSING.
185 * Each entry is -1 if this character is empty, or a non-negative
186 * integer if the character contains a branch line. The value of
187 * the integer indicates the target position for this branch line.
188 * (I.e., this array maps the current column positions to their
189 * desired positions.)
190 *
191 * The maximum capacity of this array is always
192 * sizeof(int) * 2 * column_capacity.
193 */
194 int *mapping;
195 /*
196 * A temporary array for computing the next mapping state
197 * while we are outputting a mapping line. This is stored as part
198 * of the git_graph simply so we don't have to allocate a new
199 * temporary array each time we have to output a collapsing line.
200 */
201 int *new_mapping;
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202 /*
203 * The current default column color being used. This is
204 * stored as an index into the array column_colors.
205 */
206 unsigned short default_column_color;
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207};
208
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209static struct strbuf *diff_output_prefix_callback(struct diff_options *opt, void *data)
210{
211 struct git_graph *graph = data;
212 static struct strbuf msgbuf = STRBUF_INIT;
213
5e71a84a 214 assert(opt);
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215
216 strbuf_reset(&msgbuf);
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217 if (opt->line_prefix)
218 strbuf_add(&msgbuf, opt->line_prefix,
219 opt->line_prefix_length);
220 if (graph)
221 graph_padding_line(graph, &msgbuf);
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222 return &msgbuf;
223}
224
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225static const struct diff_options *default_diffopt;
226
227void graph_setup_line_prefix(struct diff_options *diffopt)
228{
229 default_diffopt = diffopt;
230
231 /* setup an output prefix callback if necessary */
232 if (diffopt && !diffopt->output_prefix)
233 diffopt->output_prefix = diff_output_prefix_callback;
234}
235
236
7528f27d 237struct git_graph *graph_init(struct rev_info *opt)
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238{
239 struct git_graph *graph = xmalloc(sizeof(struct git_graph));
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240
241 if (!column_colors)
242 graph_set_column_colors(column_colors_ansi,
7cd52b5b 243 column_colors_ansi_max);
1e3d4119 244
c12172d2 245 graph->commit = NULL;
7528f27d 246 graph->revs = opt;
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247 graph->num_parents = 0;
248 graph->expansion_row = 0;
249 graph->state = GRAPH_PADDING;
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250 graph->prev_state = GRAPH_PADDING;
251 graph->commit_index = 0;
252 graph->prev_commit_index = 0;
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253 graph->num_columns = 0;
254 graph->num_new_columns = 0;
255 graph->mapping_size = 0;
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256 /*
257 * Start the column color at the maximum value, since we'll
258 * always increment it for the first commit we output.
259 * This way we start at 0 for the first commit.
260 */
1e3d4119 261 graph->default_column_color = column_colors_max - 1;
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262
263 /*
264 * Allocate a reasonably large default number of columns
265 * We'll automatically grow columns later if we need more room.
266 */
267 graph->column_capacity = 30;
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268 ALLOC_ARRAY(graph->columns, graph->column_capacity);
269 ALLOC_ARRAY(graph->new_columns, graph->column_capacity);
270 ALLOC_ARRAY(graph->mapping, 2 * graph->column_capacity);
271 ALLOC_ARRAY(graph->new_mapping, 2 * graph->column_capacity);
c12172d2 272
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273 /*
274 * The diff output prefix callback, with this we can make
275 * all the diff output to align with the graph lines.
276 */
277 opt->diffopt.output_prefix = diff_output_prefix_callback;
278 opt->diffopt.output_prefix_data = graph;
279
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280 return graph;
281}
282
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283static void graph_update_state(struct git_graph *graph, enum graph_state s)
284{
285 graph->prev_state = graph->state;
286 graph->state = s;
287}
288
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289static void graph_ensure_capacity(struct git_graph *graph, int num_columns)
290{
291 if (graph->column_capacity >= num_columns)
292 return;
293
294 do {
295 graph->column_capacity *= 2;
296 } while (graph->column_capacity < num_columns);
297
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298 REALLOC_ARRAY(graph->columns, graph->column_capacity);
299 REALLOC_ARRAY(graph->new_columns, graph->column_capacity);
300 REALLOC_ARRAY(graph->mapping, graph->column_capacity * 2);
301 REALLOC_ARRAY(graph->new_mapping, graph->column_capacity * 2);
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302}
303
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304/*
305 * Returns 1 if the commit will be printed in the graph output,
306 * and 0 otherwise.
307 */
3c68d67b 308static int graph_is_interesting(struct git_graph *graph, struct commit *commit)
37a75abc 309{
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310 /*
311 * If revs->boundary is set, commits whose children have
312 * been shown are always interesting, even if they have the
313 * UNINTERESTING or TREESAME flags set.
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314 */
315 if (graph->revs && graph->revs->boundary) {
4603ec0f 316 if (commit->object.flags & CHILD_SHOWN)
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317 return 1;
318 }
319
37a75abc 320 /*
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321 * Otherwise, use get_commit_action() to see if this commit is
322 * interesting
37a75abc 323 */
beb5af43 324 return get_commit_action(graph->revs, commit) == commit_show;
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325}
326
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327static struct commit_list *next_interesting_parent(struct git_graph *graph,
328 struct commit_list *orig)
329{
330 struct commit_list *list;
331
332 /*
333 * If revs->first_parent_only is set, only the first
334 * parent is interesting. None of the others are.
335 */
336 if (graph->revs->first_parent_only)
337 return NULL;
338
339 /*
340 * Return the next interesting commit after orig
341 */
342 for (list = orig->next; list; list = list->next) {
343 if (graph_is_interesting(graph, list->item))
344 return list;
345 }
346
347 return NULL;
348}
349
350static struct commit_list *first_interesting_parent(struct git_graph *graph)
351{
352 struct commit_list *parents = graph->commit->parents;
353
354 /*
355 * If this commit has no parents, ignore it
356 */
357 if (!parents)
358 return NULL;
359
360 /*
361 * If the first parent is interesting, return it
362 */
363 if (graph_is_interesting(graph, parents->item))
364 return parents;
365
366 /*
367 * Otherwise, call next_interesting_parent() to get
368 * the next interesting parent
369 */
370 return next_interesting_parent(graph, parents);
371}
372
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373static unsigned short graph_get_current_column_color(const struct git_graph *graph)
374{
daa0c3d9 375 if (!want_color(graph->revs->diffopt.use_color))
1e3d4119 376 return column_colors_max;
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377 return graph->default_column_color;
378}
379
380/*
381 * Update the graph's default column color.
382 */
383static void graph_increment_column_color(struct git_graph *graph)
384{
385 graph->default_column_color = (graph->default_column_color + 1) %
1e3d4119 386 column_colors_max;
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387}
388
389static unsigned short graph_find_commit_color(const struct git_graph *graph,
390 const struct commit *commit)
391{
392 int i;
393 for (i = 0; i < graph->num_columns; i++) {
394 if (graph->columns[i].commit == commit)
395 return graph->columns[i].color;
396 }
397 return graph_get_current_column_color(graph);
398}
399
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400static void graph_insert_into_new_columns(struct git_graph *graph,
401 struct commit *commit,
402 int *mapping_index)
403{
404 int i;
405
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406 /*
407 * If the commit is already in the new_columns list, we don't need to
408 * add it. Just update the mapping correctly.
409 */
410 for (i = 0; i < graph->num_new_columns; i++) {
411 if (graph->new_columns[i].commit == commit) {
412 graph->mapping[*mapping_index] = i;
413 *mapping_index += 2;
414 return;
415 }
416 }
417
418 /*
419 * This commit isn't already in new_columns. Add it.
420 */
421 graph->new_columns[graph->num_new_columns].commit = commit;
427fc5b8 422 graph->new_columns[graph->num_new_columns].color = graph_find_commit_color(graph, commit);
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423 graph->mapping[*mapping_index] = graph->num_new_columns;
424 *mapping_index += 2;
425 graph->num_new_columns++;
426}
427
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428static void graph_update_width(struct git_graph *graph,
429 int is_commit_in_existing_columns)
430{
431 /*
432 * Compute the width needed to display the graph for this commit.
433 * This is the maximum width needed for any row. All other rows
434 * will be padded to this width.
435 *
436 * Compute the number of columns in the widest row:
437 * Count each existing column (graph->num_columns), and each new
438 * column added by this commit.
439 */
440 int max_cols = graph->num_columns + graph->num_parents;
441
442 /*
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443 * Even if the current commit has no parents to be printed, it
444 * still takes up a column for itself.
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445 */
446 if (graph->num_parents < 1)
447 max_cols++;
448
449 /*
22e5e58a 450 * We added a column for the current commit as part of
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451 * graph->num_parents. If the current commit was already in
452 * graph->columns, then we have double counted it.
453 */
454 if (is_commit_in_existing_columns)
455 max_cols--;
456
457 /*
458 * Each column takes up 2 spaces
459 */
460 graph->width = max_cols * 2;
461}
462
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463static void graph_update_columns(struct git_graph *graph)
464{
465 struct commit_list *parent;
466 struct column *tmp_columns;
467 int max_new_columns;
468 int mapping_idx;
0724cb86 469 int i, seen_this, is_commit_in_columns;
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470
471 /*
472 * Swap graph->columns with graph->new_columns
473 * graph->columns contains the state for the previous commit,
474 * and new_columns now contains the state for our commit.
475 *
476 * We'll re-use the old columns array as storage to compute the new
477 * columns list for the commit after this one.
478 */
479 tmp_columns = graph->columns;
480 graph->columns = graph->new_columns;
481 graph->num_columns = graph->num_new_columns;
482
483 graph->new_columns = tmp_columns;
484 graph->num_new_columns = 0;
485
486 /*
487 * Now update new_columns and mapping with the information for the
488 * commit after this one.
489 *
490 * First, make sure we have enough room. At most, there will
491 * be graph->num_columns + graph->num_parents columns for the next
492 * commit.
493 */
494 max_new_columns = graph->num_columns + graph->num_parents;
495 graph_ensure_capacity(graph, max_new_columns);
496
497 /*
498 * Clear out graph->mapping
499 */
500 graph->mapping_size = 2 * max_new_columns;
501 for (i = 0; i < graph->mapping_size; i++)
502 graph->mapping[i] = -1;
503
504 /*
505 * Populate graph->new_columns and graph->mapping
506 *
507 * Some of the parents of this commit may already be in
508 * graph->columns. If so, graph->new_columns should only contain a
509 * single entry for each such commit. graph->mapping should
510 * contain information about where each current branch line is
511 * supposed to end up after the collapsing is performed.
512 */
513 seen_this = 0;
514 mapping_idx = 0;
0724cb86 515 is_commit_in_columns = 1;
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516 for (i = 0; i <= graph->num_columns; i++) {
517 struct commit *col_commit;
518 if (i == graph->num_columns) {
519 if (seen_this)
520 break;
0724cb86 521 is_commit_in_columns = 0;
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522 col_commit = graph->commit;
523 } else {
524 col_commit = graph->columns[i].commit;
525 }
526
527 if (col_commit == graph->commit) {
37a75abc 528 int old_mapping_idx = mapping_idx;
c12172d2 529 seen_this = 1;
3395908e 530 graph->commit_index = i;
a0ebe573 531 for (parent = first_interesting_parent(graph);
c12172d2 532 parent;
a0ebe573 533 parent = next_interesting_parent(graph, parent)) {
427fc5b8 534 /*
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535 * If this is a merge, or the start of a new
536 * childless column, increment the current
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537 * color.
538 */
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539 if (graph->num_parents > 1 ||
540 !is_commit_in_columns) {
427fc5b8 541 graph_increment_column_color(graph);
91e50b2c 542 }
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543 graph_insert_into_new_columns(graph,
544 parent->item,
545 &mapping_idx);
546 }
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547 /*
548 * We always need to increment mapping_idx by at
549 * least 2, even if it has no interesting parents.
550 * The current commit always takes up at least 2
551 * spaces.
552 */
553 if (mapping_idx == old_mapping_idx)
554 mapping_idx += 2;
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555 } else {
556 graph_insert_into_new_columns(graph, col_commit,
557 &mapping_idx);
558 }
559 }
560
561 /*
562 * Shrink mapping_size to be the minimum necessary
563 */
564 while (graph->mapping_size > 1 &&
565 graph->mapping[graph->mapping_size - 1] < 0)
566 graph->mapping_size--;
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567
568 /*
569 * Compute graph->width for this commit
570 */
571 graph_update_width(graph, is_commit_in_columns);
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572}
573
574void graph_update(struct git_graph *graph, struct commit *commit)
575{
576 struct commit_list *parent;
577
578 /*
579 * Set the new commit
580 */
581 graph->commit = commit;
582
583 /*
37a75abc 584 * Count how many interesting parents this commit has
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585 */
586 graph->num_parents = 0;
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587 for (parent = first_interesting_parent(graph);
588 parent;
589 parent = next_interesting_parent(graph, parent))
590 {
591 graph->num_parents++;
37a75abc 592 }
c12172d2 593
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594 /*
595 * Store the old commit_index in prev_commit_index.
596 * graph_update_columns() will update graph->commit_index for this
597 * commit.
598 */
599 graph->prev_commit_index = graph->commit_index;
600
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601 /*
602 * Call graph_update_columns() to update
603 * columns, new_columns, and mapping.
604 */
605 graph_update_columns(graph);
606
607 graph->expansion_row = 0;
608
609 /*
610 * Update graph->state.
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611 * Note that we don't call graph_update_state() here, since
612 * we don't want to update graph->prev_state. No line for
613 * graph->state was ever printed.
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614 *
615 * If the previous commit didn't get to the GRAPH_PADDING state,
616 * it never finished its output. Goto GRAPH_SKIP, to print out
617 * a line to indicate that portion of the graph is missing.
618 *
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619 * If there are 3 or more parents, we may need to print extra rows
620 * before the commit, to expand the branch lines around it and make
621 * room for it. We need to do this only if there is a branch row
622 * (or more) to the right of this commit.
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623 *
624 * If there are less than 3 parents, we can immediately print the
625 * commit line.
626 */
627 if (graph->state != GRAPH_PADDING)
628 graph->state = GRAPH_SKIP;
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629 else if (graph->num_parents >= 3 &&
630 graph->commit_index < (graph->num_columns - 1))
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631 graph->state = GRAPH_PRE_COMMIT;
632 else
633 graph->state = GRAPH_COMMIT;
634}
635
636static int graph_is_mapping_correct(struct git_graph *graph)
637{
638 int i;
639
640 /*
641 * The mapping is up to date if each entry is at its target,
642 * or is 1 greater than its target.
643 * (If it is 1 greater than the target, '/' will be printed, so it
644 * will look correct on the next row.)
645 */
646 for (i = 0; i < graph->mapping_size; i++) {
647 int target = graph->mapping[i];
648 if (target < 0)
649 continue;
650 if (target == (i / 2))
651 continue;
652 return 0;
653 }
654
655 return 1;
656}
657
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658static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb,
659 int chars_written)
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660{
661 /*
662 * Add additional spaces to the end of the strbuf, so that all
663 * lines for a particular commit have the same width.
664 *
665 * This way, fields printed to the right of the graph will remain
666 * aligned for the entire commit.
c12172d2 667 */
0724cb86 668 int extra;
427fc5b8 669 if (chars_written >= graph->width)
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670 return;
671
427fc5b8 672 extra = graph->width - chars_written;
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673 strbuf_addf(sb, "%*s", (int) extra, "");
674}
675
676static void graph_output_padding_line(struct git_graph *graph,
677 struct strbuf *sb)
678{
679 int i;
680
681 /*
682 * We could conceivable be called with a NULL commit
683 * if our caller has a bug, and invokes graph_next_line()
684 * immediately after graph_init(), without first calling
685 * graph_update(). Return without outputting anything in this
686 * case.
687 */
688 if (!graph->commit)
689 return;
690
691 /*
692 * Output a padding row, that leaves all branch lines unchanged
693 */
694 for (i = 0; i < graph->num_new_columns; i++) {
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695 strbuf_write_column(sb, &graph->new_columns[i], '|');
696 strbuf_addch(sb, ' ');
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697 }
698
427fc5b8 699 graph_pad_horizontally(graph, sb, graph->num_new_columns * 2);
c12172d2
AS
700}
701
3ad87c80
JK
702
703int graph_width(struct git_graph *graph)
704{
705 return graph->width;
706}
707
708
c12172d2
AS
709static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
710{
711 /*
712 * Output an ellipsis to indicate that a portion
713 * of the graph is missing.
714 */
715 strbuf_addstr(sb, "...");
427fc5b8 716 graph_pad_horizontally(graph, sb, 3);
c12172d2 717
f1979d6b
AS
718 if (graph->num_parents >= 3 &&
719 graph->commit_index < (graph->num_columns - 1))
3395908e 720 graph_update_state(graph, GRAPH_PRE_COMMIT);
c12172d2 721 else
3395908e 722 graph_update_state(graph, GRAPH_COMMIT);
c12172d2
AS
723}
724
725static void graph_output_pre_commit_line(struct git_graph *graph,
726 struct strbuf *sb)
727{
728 int num_expansion_rows;
729 int i, seen_this;
427fc5b8 730 int chars_written;
c12172d2
AS
731
732 /*
733 * This function formats a row that increases the space around a commit
734 * with multiple parents, to make room for it. It should only be
735 * called when there are 3 or more parents.
736 *
737 * We need 2 extra rows for every parent over 2.
738 */
739 assert(graph->num_parents >= 3);
740 num_expansion_rows = (graph->num_parents - 2) * 2;
741
742 /*
743 * graph->expansion_row tracks the current expansion row we are on.
744 * It should be in the range [0, num_expansion_rows - 1]
745 */
746 assert(0 <= graph->expansion_row &&
747 graph->expansion_row < num_expansion_rows);
748
749 /*
750 * Output the row
751 */
752 seen_this = 0;
427fc5b8 753 chars_written = 0;
c12172d2
AS
754 for (i = 0; i < graph->num_columns; i++) {
755 struct column *col = &graph->columns[i];
756 if (col->commit == graph->commit) {
757 seen_this = 1;
427fc5b8 758 strbuf_write_column(sb, col, '|');
36a31fea
AC
759 strbuf_addf(sb, "%*s", graph->expansion_row, "");
760 chars_written += 1 + graph->expansion_row;
3395908e
AS
761 } else if (seen_this && (graph->expansion_row == 0)) {
762 /*
763 * This is the first line of the pre-commit output.
764 * If the previous commit was a merge commit and
765 * ended in the GRAPH_POST_MERGE state, all branch
766 * lines after graph->prev_commit_index were
767 * printed as "\" on the previous line. Continue
768 * to print them as "\" on this line. Otherwise,
769 * print the branch lines as "|".
770 */
771 if (graph->prev_state == GRAPH_POST_MERGE &&
772 graph->prev_commit_index < i)
427fc5b8 773 strbuf_write_column(sb, col, '\\');
3395908e 774 else
427fc5b8
AC
775 strbuf_write_column(sb, col, '|');
776 chars_written++;
3395908e 777 } else if (seen_this && (graph->expansion_row > 0)) {
427fc5b8
AC
778 strbuf_write_column(sb, col, '\\');
779 chars_written++;
c12172d2 780 } else {
427fc5b8
AC
781 strbuf_write_column(sb, col, '|');
782 chars_written++;
c12172d2 783 }
427fc5b8
AC
784 strbuf_addch(sb, ' ');
785 chars_written++;
c12172d2
AS
786 }
787
427fc5b8 788 graph_pad_horizontally(graph, sb, chars_written);
c12172d2
AS
789
790 /*
791 * Increment graph->expansion_row,
792 * and move to state GRAPH_COMMIT if necessary
793 */
794 graph->expansion_row++;
795 if (graph->expansion_row >= num_expansion_rows)
3395908e 796 graph_update_state(graph, GRAPH_COMMIT);
c12172d2
AS
797}
798
3c68d67b
AS
799static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
800{
801 /*
802 * For boundary commits, print 'o'
803 * (We should only see boundary commits when revs->boundary is set.)
804 */
805 if (graph->commit->object.flags & BOUNDARY) {
806 assert(graph->revs->boundary);
807 strbuf_addch(sb, 'o');
808 return;
809 }
810
811 /*
1df2d656 812 * get_revision_mark() handles all other cases without assert()
3c68d67b 813 */
1df2d656 814 strbuf_addstr(sb, get_revision_mark(graph->revs, graph->commit));
3c68d67b
AS
815}
816
427fc5b8
AC
817/*
818 * Draw an octopus merge and return the number of characters written.
819 */
820static int graph_draw_octopus_merge(struct git_graph *graph,
821 struct strbuf *sb)
822{
823 /*
824 * Here dashless_commits represents the number of parents
825 * which don't need to have dashes (because their edges fit
826 * neatly under the commit).
827 */
828 const int dashless_commits = 2;
829 int col_num, i;
830 int num_dashes =
831 ((graph->num_parents - dashless_commits) * 2) - 1;
832 for (i = 0; i < num_dashes; i++) {
339c17bc 833 col_num = (i / 2) + dashless_commits + graph->commit_index;
427fc5b8
AC
834 strbuf_write_column(sb, &graph->new_columns[col_num], '-');
835 }
339c17bc 836 col_num = (i / 2) + dashless_commits + graph->commit_index;
427fc5b8
AC
837 strbuf_write_column(sb, &graph->new_columns[col_num], '.');
838 return num_dashes + 1;
839}
840
064bfbde 841static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
c12172d2
AS
842{
843 int seen_this = 0;
427fc5b8 844 int i, chars_written;
c12172d2
AS
845
846 /*
847 * Output the row containing this commit
848 * Iterate up to and including graph->num_columns,
849 * since the current commit may not be in any of the existing
850 * columns. (This happens when the current commit doesn't have any
851 * children that we have already processed.)
852 */
853 seen_this = 0;
427fc5b8 854 chars_written = 0;
c12172d2 855 for (i = 0; i <= graph->num_columns; i++) {
427fc5b8 856 struct column *col = &graph->columns[i];
c12172d2
AS
857 struct commit *col_commit;
858 if (i == graph->num_columns) {
859 if (seen_this)
860 break;
861 col_commit = graph->commit;
862 } else {
863 col_commit = graph->columns[i].commit;
864 }
865
866 if (col_commit == graph->commit) {
867 seen_this = 1;
3c68d67b 868 graph_output_commit_char(graph, sb);
427fc5b8 869 chars_written++;
c12172d2 870
a6c1a382 871 if (graph->num_parents > 2)
427fc5b8
AC
872 chars_written += graph_draw_octopus_merge(graph,
873 sb);
3395908e 874 } else if (seen_this && (graph->num_parents > 2)) {
427fc5b8
AC
875 strbuf_write_column(sb, col, '\\');
876 chars_written++;
3395908e
AS
877 } else if (seen_this && (graph->num_parents == 2)) {
878 /*
879 * This is a 2-way merge commit.
880 * There is no GRAPH_PRE_COMMIT stage for 2-way
881 * merges, so this is the first line of output
882 * for this commit. Check to see what the previous
883 * line of output was.
884 *
885 * If it was GRAPH_POST_MERGE, the branch line
886 * coming into this commit may have been '\',
887 * and not '|' or '/'. If so, output the branch
888 * line as '\' on this line, instead of '|'. This
889 * makes the output look nicer.
890 */
891 if (graph->prev_state == GRAPH_POST_MERGE &&
892 graph->prev_commit_index < i)
427fc5b8 893 strbuf_write_column(sb, col, '\\');
3395908e 894 else
427fc5b8
AC
895 strbuf_write_column(sb, col, '|');
896 chars_written++;
c12172d2 897 } else {
427fc5b8
AC
898 strbuf_write_column(sb, col, '|');
899 chars_written++;
c12172d2 900 }
427fc5b8
AC
901 strbuf_addch(sb, ' ');
902 chars_written++;
c12172d2
AS
903 }
904
427fc5b8 905 graph_pad_horizontally(graph, sb, chars_written);
c12172d2
AS
906
907 /*
908 * Update graph->state
909 */
910 if (graph->num_parents > 1)
3395908e 911 graph_update_state(graph, GRAPH_POST_MERGE);
c12172d2 912 else if (graph_is_mapping_correct(graph))
3395908e 913 graph_update_state(graph, GRAPH_PADDING);
c12172d2 914 else
3395908e 915 graph_update_state(graph, GRAPH_COLLAPSING);
c12172d2
AS
916}
917
427fc5b8
AC
918static struct column *find_new_column_by_commit(struct git_graph *graph,
919 struct commit *commit)
920{
921 int i;
922 for (i = 0; i < graph->num_new_columns; i++) {
923 if (graph->new_columns[i].commit == commit)
924 return &graph->new_columns[i];
925 }
67da52be 926 return NULL;
427fc5b8
AC
927}
928
064bfbde 929static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
c12172d2
AS
930{
931 int seen_this = 0;
427fc5b8 932 int i, j, chars_written;
c12172d2
AS
933
934 /*
935 * Output the post-merge row
936 */
427fc5b8 937 chars_written = 0;
c12172d2 938 for (i = 0; i <= graph->num_columns; i++) {
427fc5b8 939 struct column *col = &graph->columns[i];
c12172d2
AS
940 struct commit *col_commit;
941 if (i == graph->num_columns) {
942 if (seen_this)
943 break;
944 col_commit = graph->commit;
945 } else {
427fc5b8 946 col_commit = col->commit;
c12172d2
AS
947 }
948
949 if (col_commit == graph->commit) {
427fc5b8
AC
950 /*
951 * Since the current commit is a merge find
952 * the columns for the parent commits in
953 * new_columns and use those to format the
954 * edges.
955 */
956 struct commit_list *parents = NULL;
957 struct column *par_column;
c12172d2 958 seen_this = 1;
427fc5b8
AC
959 parents = first_interesting_parent(graph);
960 assert(parents);
961 par_column = find_new_column_by_commit(graph, parents->item);
962 assert(par_column);
963
964 strbuf_write_column(sb, par_column, '|');
965 chars_written++;
966 for (j = 0; j < graph->num_parents - 1; j++) {
967 parents = next_interesting_parent(graph, parents);
968 assert(parents);
969 par_column = find_new_column_by_commit(graph, parents->item);
970 assert(par_column);
971 strbuf_write_column(sb, par_column, '\\');
972 strbuf_addch(sb, ' ');
973 }
974 chars_written += j * 2;
3395908e 975 } else if (seen_this) {
427fc5b8
AC
976 strbuf_write_column(sb, col, '\\');
977 strbuf_addch(sb, ' ');
978 chars_written += 2;
c12172d2 979 } else {
427fc5b8
AC
980 strbuf_write_column(sb, col, '|');
981 strbuf_addch(sb, ' ');
982 chars_written += 2;
c12172d2
AS
983 }
984 }
985
427fc5b8 986 graph_pad_horizontally(graph, sb, chars_written);
c12172d2
AS
987
988 /*
989 * Update graph->state
990 */
991 if (graph_is_mapping_correct(graph))
3395908e 992 graph_update_state(graph, GRAPH_PADDING);
c12172d2 993 else
3395908e 994 graph_update_state(graph, GRAPH_COLLAPSING);
c12172d2
AS
995}
996
064bfbde 997static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb)
c12172d2
AS
998{
999 int i;
eaf158f8
AC
1000 short used_horizontal = 0;
1001 int horizontal_edge = -1;
1002 int horizontal_edge_target = -1;
c12172d2
AS
1003
1004 /*
1005 * Clear out the new_mapping array
1006 */
1007 for (i = 0; i < graph->mapping_size; i++)
1008 graph->new_mapping[i] = -1;
1009
1010 for (i = 0; i < graph->mapping_size; i++) {
1011 int target = graph->mapping[i];
1012 if (target < 0)
1013 continue;
1014
1015 /*
1016 * Since update_columns() always inserts the leftmost
1017 * column first, each branch's target location should
1018 * always be either its current location or to the left of
1019 * its current location.
1020 *
1021 * We never have to move branches to the right. This makes
1022 * the graph much more legible, since whenever branches
1023 * cross, only one is moving directions.
1024 */
1025 assert(target * 2 <= i);
1026
1027 if (target * 2 == i) {
1028 /*
1029 * This column is already in the
1030 * correct place
1031 */
1032 assert(graph->new_mapping[i] == -1);
1033 graph->new_mapping[i] = target;
1034 } else if (graph->new_mapping[i - 1] < 0) {
1035 /*
1036 * Nothing is to the left.
1037 * Move to the left by one
1038 */
1039 graph->new_mapping[i - 1] = target;
eaf158f8
AC
1040 /*
1041 * If there isn't already an edge moving horizontally
1042 * select this one.
1043 */
1044 if (horizontal_edge == -1) {
1045 int j;
1046 horizontal_edge = i;
1047 horizontal_edge_target = target;
1048 /*
1049 * The variable target is the index of the graph
1050 * column, and therefore target*2+3 is the
1051 * actual screen column of the first horizontal
1052 * line.
1053 */
1054 for (j = (target * 2)+3; j < (i - 2); j += 2)
1055 graph->new_mapping[j] = target;
1056 }
c12172d2
AS
1057 } else if (graph->new_mapping[i - 1] == target) {
1058 /*
1059 * There is a branch line to our left
1060 * already, and it is our target. We
1061 * combine with this line, since we share
1062 * the same parent commit.
1063 *
1064 * We don't have to add anything to the
1065 * output or new_mapping, since the
1066 * existing branch line has already taken
1067 * care of it.
1068 */
1069 } else {
1070 /*
1071 * There is a branch line to our left,
1072 * but it isn't our target. We need to
1073 * cross over it.
1074 *
1075 * The space just to the left of this
1076 * branch should always be empty.
eaf158f8
AC
1077 *
1078 * The branch to the left of that space
1079 * should be our eventual target.
c12172d2
AS
1080 */
1081 assert(graph->new_mapping[i - 1] > target);
1082 assert(graph->new_mapping[i - 2] < 0);
eaf158f8 1083 assert(graph->new_mapping[i - 3] == target);
c12172d2 1084 graph->new_mapping[i - 2] = target;
eaf158f8
AC
1085 /*
1086 * Mark this branch as the horizontal edge to
1087 * prevent any other edges from moving
1088 * horizontally.
1089 */
1090 if (horizontal_edge == -1)
1091 horizontal_edge = i;
c12172d2
AS
1092 }
1093 }
1094
1095 /*
1096 * The new mapping may be 1 smaller than the old mapping
1097 */
1098 if (graph->new_mapping[graph->mapping_size - 1] < 0)
1099 graph->mapping_size--;
1100
1101 /*
1102 * Output out a line based on the new mapping info
1103 */
1104 for (i = 0; i < graph->mapping_size; i++) {
1105 int target = graph->new_mapping[i];
1106 if (target < 0)
1107 strbuf_addch(sb, ' ');
1108 else if (target * 2 == i)
427fc5b8 1109 strbuf_write_column(sb, &graph->new_columns[target], '|');
eaf158f8
AC
1110 else if (target == horizontal_edge_target &&
1111 i != horizontal_edge - 1) {
1112 /*
1113 * Set the mappings for all but the
1114 * first segment to -1 so that they
1115 * won't continue into the next line.
1116 */
1117 if (i != (target * 2)+3)
1118 graph->new_mapping[i] = -1;
1119 used_horizontal = 1;
1120 strbuf_write_column(sb, &graph->new_columns[target], '_');
1121 } else {
1122 if (used_horizontal && i < horizontal_edge)
1123 graph->new_mapping[i] = -1;
427fc5b8 1124 strbuf_write_column(sb, &graph->new_columns[target], '/');
eaf158f8
AC
1125
1126 }
c12172d2
AS
1127 }
1128
427fc5b8 1129 graph_pad_horizontally(graph, sb, graph->mapping_size);
c12172d2
AS
1130
1131 /*
1132 * Swap mapping and new_mapping
1133 */
35d803bc 1134 SWAP(graph->mapping, graph->new_mapping);
c12172d2
AS
1135
1136 /*
1137 * If graph->mapping indicates that all of the branch lines
1138 * are already in the correct positions, we are done.
1139 * Otherwise, we need to collapse some branch lines together.
1140 */
1141 if (graph_is_mapping_correct(graph))
3395908e 1142 graph_update_state(graph, GRAPH_PADDING);
c12172d2
AS
1143}
1144
ac751a0b 1145int graph_next_line(struct git_graph *graph, struct strbuf *sb)
c12172d2
AS
1146{
1147 switch (graph->state) {
1148 case GRAPH_PADDING:
1149 graph_output_padding_line(graph, sb);
1150 return 0;
1151 case GRAPH_SKIP:
1152 graph_output_skip_line(graph, sb);
1153 return 0;
1154 case GRAPH_PRE_COMMIT:
1155 graph_output_pre_commit_line(graph, sb);
1156 return 0;
1157 case GRAPH_COMMIT:
1158 graph_output_commit_line(graph, sb);
1159 return 1;
1160 case GRAPH_POST_MERGE:
1161 graph_output_post_merge_line(graph, sb);
1162 return 0;
1163 case GRAPH_COLLAPSING:
1164 graph_output_collapsing_line(graph, sb);
1165 return 0;
1166 }
1167
1168 assert(0);
1169 return 0;
1170}
1171
064bfbde 1172static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
c12172d2 1173{
415792ed 1174 int i;
16477935 1175 int chars_written = 0;
c12172d2
AS
1176
1177 if (graph->state != GRAPH_COMMIT) {
1178 graph_next_line(graph, sb);
1179 return;
1180 }
1181
1182 /*
1183 * Output the row containing this commit
1184 * Iterate up to and including graph->num_columns,
1185 * since the current commit may not be in any of the existing
1186 * columns. (This happens when the current commit doesn't have any
1187 * children that we have already processed.)
1188 */
1189 for (i = 0; i < graph->num_columns; i++) {
427fc5b8 1190 struct column *col = &graph->columns[i];
16477935 1191
0176e7a7 1192 strbuf_write_column(sb, col, '|');
16477935
JK
1193 chars_written++;
1194
1195 if (col->commit == graph->commit && graph->num_parents > 2) {
1196 int len = (graph->num_parents - 2) * 2;
1197 strbuf_addchars(sb, ' ', len);
1198 chars_written += len;
1199 } else {
427fc5b8 1200 strbuf_addch(sb, ' ');
16477935
JK
1201 chars_written++;
1202 }
c12172d2
AS
1203 }
1204
16477935 1205 graph_pad_horizontally(graph, sb, chars_written);
3395908e
AS
1206
1207 /*
1208 * Update graph->prev_state since we have output a padding line
1209 */
1210 graph->prev_state = GRAPH_PADDING;
c12172d2
AS
1211}
1212
1213int graph_is_commit_finished(struct git_graph const *graph)
1214{
1215 return (graph->state == GRAPH_PADDING);
1216}
1217
1218void graph_show_commit(struct git_graph *graph)
1219{
f285a2d7 1220 struct strbuf msgbuf = STRBUF_INIT;
c12172d2
AS
1221 int shown_commit_line = 0;
1222
660e113c
JK
1223 graph_show_line_prefix(default_diffopt);
1224
c12172d2
AS
1225 if (!graph)
1226 return;
1227
a48ec241
JK
1228 /*
1229 * When showing a diff of a merge against each of its parents, we
1230 * are called once for each parent without graph_update having been
1231 * called. In this case, simply output a single padding line.
1232 */
1233 if (graph_is_commit_finished(graph)) {
1234 graph_show_padding(graph);
1235 shown_commit_line = 1;
1236 }
1237
656197ad 1238 while (!shown_commit_line && !graph_is_commit_finished(graph)) {
c12172d2 1239 shown_commit_line = graph_next_line(graph, &msgbuf);
c61008fd
JS
1240 fwrite(msgbuf.buf, sizeof(char), msgbuf.len,
1241 graph->revs->diffopt.file);
660e113c 1242 if (!shown_commit_line) {
c61008fd 1243 putc('\n', graph->revs->diffopt.file);
660e113c
JK
1244 graph_show_line_prefix(&graph->revs->diffopt);
1245 }
c12172d2
AS
1246 strbuf_setlen(&msgbuf, 0);
1247 }
1248
1249 strbuf_release(&msgbuf);
1250}
1251
1252void graph_show_oneline(struct git_graph *graph)
1253{
f285a2d7 1254 struct strbuf msgbuf = STRBUF_INIT;
c12172d2 1255
660e113c
JK
1256 graph_show_line_prefix(default_diffopt);
1257
c12172d2
AS
1258 if (!graph)
1259 return;
1260
c12172d2 1261 graph_next_line(graph, &msgbuf);
c61008fd 1262 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, graph->revs->diffopt.file);
c12172d2
AS
1263 strbuf_release(&msgbuf);
1264}
1265
1266void graph_show_padding(struct git_graph *graph)
1267{
f285a2d7 1268 struct strbuf msgbuf = STRBUF_INIT;
c12172d2 1269
660e113c
JK
1270 graph_show_line_prefix(default_diffopt);
1271
c12172d2
AS
1272 if (!graph)
1273 return;
1274
c12172d2 1275 graph_padding_line(graph, &msgbuf);
c61008fd 1276 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, graph->revs->diffopt.file);
c12172d2
AS
1277 strbuf_release(&msgbuf);
1278}
1279
1280int graph_show_remainder(struct git_graph *graph)
1281{
f285a2d7 1282 struct strbuf msgbuf = STRBUF_INIT;
c12172d2
AS
1283 int shown = 0;
1284
660e113c
JK
1285 graph_show_line_prefix(default_diffopt);
1286
c12172d2
AS
1287 if (!graph)
1288 return 0;
1289
1290 if (graph_is_commit_finished(graph))
1291 return 0;
1292
c12172d2
AS
1293 for (;;) {
1294 graph_next_line(graph, &msgbuf);
c61008fd
JS
1295 fwrite(msgbuf.buf, sizeof(char), msgbuf.len,
1296 graph->revs->diffopt.file);
c12172d2
AS
1297 strbuf_setlen(&msgbuf, 0);
1298 shown = 1;
1299
660e113c 1300 if (!graph_is_commit_finished(graph)) {
c61008fd 1301 putc('\n', graph->revs->diffopt.file);
660e113c
JK
1302 graph_show_line_prefix(&graph->revs->diffopt);
1303 } else {
c12172d2 1304 break;
660e113c 1305 }
c12172d2
AS
1306 }
1307 strbuf_release(&msgbuf);
1308
1309 return shown;
1310}
1311
660e113c
JK
1312static void graph_show_strbuf(struct git_graph *graph,
1313 FILE *file,
1314 struct strbuf const *sb)
c12172d2
AS
1315{
1316 char *p;
1317
c12172d2
AS
1318 /*
1319 * Print the strbuf line by line,
1320 * and display the graph info before each line but the first.
1321 */
1322 p = sb->buf;
1323 while (p) {
1324 size_t len;
1325 char *next_p = strchr(p, '\n');
1326 if (next_p) {
1327 next_p++;
1328 len = next_p - p;
1329 } else {
1330 len = (sb->buf + sb->len) - p;
1331 }
660e113c 1332 fwrite(p, sizeof(char), len, file);
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AS
1333 if (next_p && *next_p != '\0')
1334 graph_show_oneline(graph);
1335 p = next_p;
1336 }
1337}
1338
1339void graph_show_commit_msg(struct git_graph *graph,
660e113c 1340 FILE *file,
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AS
1341 struct strbuf const *sb)
1342{
1343 int newline_terminated;
1344
c12172d2
AS
1345 /*
1346 * Show the commit message
1347 */
660e113c
JK
1348 graph_show_strbuf(graph, file, sb);
1349
1350 if (!graph)
1351 return;
1352
1353 newline_terminated = (sb->len && sb->buf[sb->len - 1] == '\n');
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AS
1354
1355 /*
1356 * If there is more output needed for this commit, show it now
1357 */
1358 if (!graph_is_commit_finished(graph)) {
1359 /*
1360 * If sb doesn't have a terminating newline, print one now,
1361 * so we can start the remainder of the graph output on a
1362 * new line.
1363 */
1364 if (!newline_terminated)
660e113c 1365 putc('\n', file);
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AS
1366
1367 graph_show_remainder(graph);
1368
1369 /*
1370 * If sb ends with a newline, our output should too.
1371 */
1372 if (newline_terminated)
660e113c 1373 putc('\n', file);
c12172d2
AS
1374 }
1375}