diff options
Diffstat (limited to 'third_party/git/graph.c')
| -rw-r--r-- | third_party/git/graph.c | 1536 |
1 files changed, 1536 insertions, 0 deletions
diff --git a/third_party/git/graph.c b/third_party/git/graph.c new file mode 100644 index 000000000000..4fb25ad464db --- /dev/null +++ b/third_party/git/graph.c @@ -0,0 +1,1536 @@ +#include "cache.h" +#include "config.h" +#include "commit.h" +#include "color.h" +#include "graph.h" +#include "revision.h" +#include "argv-array.h" + +/* Internal API */ + +/* + * Output a padding line in the graph. + * This is similar to graph_next_line(). However, it is guaranteed to + * never print the current commit line. Instead, if the commit line is + * next, it will simply output a line of vertical padding, extending the + * branch lines downwards, but leaving them otherwise unchanged. + */ +static void graph_padding_line(struct git_graph *graph, struct strbuf *sb); + +/* + * Print a strbuf. If the graph is non-NULL, all lines but the first will be + * prefixed with the graph output. + * + * If the strbuf ends with a newline, the output will end after this + * newline. A new graph line will not be printed after the final newline. + * If the strbuf is empty, no output will be printed. + * + * Since the first line will not include the graph output, the caller is + * responsible for printing this line's graph (perhaps via + * graph_show_commit() or graph_show_oneline()) before calling + * graph_show_strbuf(). + * + * Note that unlike some other graph display functions, you must pass the file + * handle directly. It is assumed that this is the same file handle as the + * file specified by the graph diff options. This is necessary so that + * graph_show_strbuf can be called even with a NULL graph. + * If a NULL graph is supplied, the strbuf is printed as-is. + */ +static void graph_show_strbuf(struct git_graph *graph, + FILE *file, + struct strbuf const *sb); + +/* + * TODO: + * - Limit the number of columns, similar to the way gitk does. + * If we reach more than a specified number of columns, omit + * sections of some columns. + */ + +struct column { + /* + * The parent commit of this column. + */ + struct commit *commit; + /* + * The color to (optionally) print this column in. This is an + * index into column_colors. + */ + unsigned short color; +}; + +enum graph_state { + GRAPH_PADDING, + GRAPH_SKIP, + GRAPH_PRE_COMMIT, + GRAPH_COMMIT, + GRAPH_POST_MERGE, + GRAPH_COLLAPSING +}; + +static void graph_show_line_prefix(const struct diff_options *diffopt) +{ + if (!diffopt || !diffopt->line_prefix) + return; + + fwrite(diffopt->line_prefix, + sizeof(char), + diffopt->line_prefix_length, + diffopt->file); +} + +static const char **column_colors; +static unsigned short column_colors_max; + +static void parse_graph_colors_config(struct argv_array *colors, const char *string) +{ + const char *end, *start; + + start = string; + end = string + strlen(string); + while (start < end) { + const char *comma = strchrnul(start, ','); + char color[COLOR_MAXLEN]; + + if (!color_parse_mem(start, comma - start, color)) + argv_array_push(colors, color); + else + warning(_("ignore invalid color '%.*s' in log.graphColors"), + (int)(comma - start), start); + start = comma + 1; + } + argv_array_push(colors, GIT_COLOR_RESET); +} + +void graph_set_column_colors(const char **colors, unsigned short colors_max) +{ + column_colors = colors; + column_colors_max = colors_max; +} + +static const char *column_get_color_code(unsigned short color) +{ + return column_colors[color]; +} + +struct graph_line { + struct strbuf *buf; + size_t width; +}; + +static inline void graph_line_addch(struct graph_line *line, int c) +{ + strbuf_addch(line->buf, c); + line->width++; +} + +static inline void graph_line_addchars(struct graph_line *line, int c, size_t n) +{ + strbuf_addchars(line->buf, c, n); + line->width += n; +} + +static inline void graph_line_addstr(struct graph_line *line, const char *s) +{ + strbuf_addstr(line->buf, s); + line->width += strlen(s); +} + +static inline void graph_line_addcolor(struct graph_line *line, unsigned short color) +{ + strbuf_addstr(line->buf, column_get_color_code(color)); +} + +static void graph_line_write_column(struct graph_line *line, const struct column *c, + char col_char) +{ + if (c->color < column_colors_max) + graph_line_addcolor(line, c->color); + graph_line_addch(line, col_char); + if (c->color < column_colors_max) + graph_line_addcolor(line, column_colors_max); +} + +struct git_graph { + /* + * The commit currently being processed + */ + struct commit *commit; + /* The rev-info used for the current traversal */ + struct rev_info *revs; + /* + * The number of interesting parents that this commit has. + * + * Note that this is not the same as the actual number of parents. + * This count excludes parents that won't be printed in the graph + * output, as determined by graph_is_interesting(). + */ + int num_parents; + /* + * The width of the graph output for this commit. + * All rows for this commit are padded to this width, so that + * messages printed after the graph output are aligned. + */ + int width; + /* + * The next expansion row to print + * when state is GRAPH_PRE_COMMIT + */ + int expansion_row; + /* + * The current output state. + * This tells us what kind of line graph_next_line() should output. + */ + enum graph_state state; + /* + * The output state for the previous line of output. + * This is primarily used to determine how the first merge line + * should appear, based on the last line of the previous commit. + */ + enum graph_state prev_state; + /* + * The index of the column that refers to this commit. + * + * If none of the incoming columns refer to this commit, + * this will be equal to num_columns. + */ + int commit_index; + /* + * The commit_index for the previously displayed commit. + * + * This is used to determine how the first line of a merge + * graph output should appear, based on the last line of the + * previous commit. + */ + int prev_commit_index; + /* + * Which layout variant to use to display merge commits. If the + * commit's first parent is known to be in a column to the left of the + * merge, then this value is 0 and we use the layout on the left. + * Otherwise, the value is 1 and the layout on the right is used. This + * field tells us how many columns the first parent occupies. + * + * 0) 1) + * + * | | | *-. | | *---. + * | |_|/|\ \ | | |\ \ \ + * |/| | | | | | | | | | * + */ + int merge_layout; + /* + * The number of columns added to the graph by the current commit. For + * 2-way and octopus merges, this is usually one less than the + * number of parents: + * + * | | | | | \ + * | * | | *---. \ + * | |\ \ | |\ \ \ \ + * | | | | | | | | | | + * + * num_parents: 2 num_parents: 4 + * edges_added: 1 edges_added: 3 + * + * For left-skewed merges, the first parent fuses with its neighbor and + * so one less column is added: + * + * | | | | | \ + * | * | | *-. \ + * |/| | |/|\ \ \ + * | | | | | | | | + * + * num_parents: 2 num_parents: 4 + * edges_added: 0 edges_added: 2 + * + * This number determines how edges to the right of the merge are + * displayed in commit and post-merge lines; if no columns have been + * added then a vertical line should be used where a right-tracking + * line would otherwise be used. + * + * | * \ | * | + * | |\ \ |/| | + * | | * \ | * | + */ + int edges_added; + /* + * The number of columns added by the previous commit, which is used to + * smooth edges appearing to the right of a commit in a commit line + * following a post-merge line. + */ + int prev_edges_added; + /* + * The maximum number of columns that can be stored in the columns + * and new_columns arrays. This is also half the number of entries + * that can be stored in the mapping and old_mapping arrays. + */ + int column_capacity; + /* + * The number of columns (also called "branch lines" in some places) + */ + int num_columns; + /* + * The number of columns in the new_columns array + */ + int num_new_columns; + /* + * The number of entries in the mapping array + */ + int mapping_size; + /* + * The column state before we output the current commit. + */ + struct column *columns; + /* + * The new column state after we output the current commit. + * Only valid when state is GRAPH_COLLAPSING. + */ + struct column *new_columns; + /* + * An array that tracks the current state of each + * character in the output line during state GRAPH_COLLAPSING. + * Each entry is -1 if this character is empty, or a non-negative + * integer if the character contains a branch line. The value of + * the integer indicates the target position for this branch line. + * (I.e., this array maps the current column positions to their + * desired positions.) + * + * The maximum capacity of this array is always + * sizeof(int) * 2 * column_capacity. + */ + int *mapping; + /* + * A copy of the contents of the mapping array from the last commit, + * which we use to improve the display of columns that are tracking + * from right to left through a commit line. We also use this to + * avoid allocating a fresh array when we compute the next mapping. + */ + int *old_mapping; + /* + * The current default column color being used. This is + * stored as an index into the array column_colors. + */ + unsigned short default_column_color; +}; + +static struct strbuf *diff_output_prefix_callback(struct diff_options *opt, void *data) +{ + struct git_graph *graph = data; + static struct strbuf msgbuf = STRBUF_INIT; + + assert(opt); + + strbuf_reset(&msgbuf); + if (opt->line_prefix) + strbuf_add(&msgbuf, opt->line_prefix, + opt->line_prefix_length); + if (graph) + graph_padding_line(graph, &msgbuf); + return &msgbuf; +} + +static const struct diff_options *default_diffopt; + +void graph_setup_line_prefix(struct diff_options *diffopt) +{ + default_diffopt = diffopt; + + /* setup an output prefix callback if necessary */ + if (diffopt && !diffopt->output_prefix) + diffopt->output_prefix = diff_output_prefix_callback; +} + + +struct git_graph *graph_init(struct rev_info *opt) +{ + struct git_graph *graph = xmalloc(sizeof(struct git_graph)); + + if (!column_colors) { + char *string; + if (git_config_get_string("log.graphcolors", &string)) { + /* not configured -- use default */ + graph_set_column_colors(column_colors_ansi, + column_colors_ansi_max); + } else { + static struct argv_array custom_colors = ARGV_ARRAY_INIT; + argv_array_clear(&custom_colors); + parse_graph_colors_config(&custom_colors, string); + free(string); + /* graph_set_column_colors takes a max-index, not a count */ + graph_set_column_colors(custom_colors.argv, + custom_colors.argc - 1); + } + } + + graph->commit = NULL; + graph->revs = opt; + graph->num_parents = 0; + graph->expansion_row = 0; + graph->state = GRAPH_PADDING; + graph->prev_state = GRAPH_PADDING; + graph->commit_index = 0; + graph->prev_commit_index = 0; + graph->merge_layout = 0; + graph->edges_added = 0; + graph->prev_edges_added = 0; + graph->num_columns = 0; + graph->num_new_columns = 0; + graph->mapping_size = 0; + /* + * Start the column color at the maximum value, since we'll + * always increment it for the first commit we output. + * This way we start at 0 for the first commit. + */ + graph->default_column_color = column_colors_max - 1; + + /* + * Allocate a reasonably large default number of columns + * We'll automatically grow columns later if we need more room. + */ + graph->column_capacity = 30; + ALLOC_ARRAY(graph->columns, graph->column_capacity); + ALLOC_ARRAY(graph->new_columns, graph->column_capacity); + ALLOC_ARRAY(graph->mapping, 2 * graph->column_capacity); + ALLOC_ARRAY(graph->old_mapping, 2 * graph->column_capacity); + + /* + * The diff output prefix callback, with this we can make + * all the diff output to align with the graph lines. + */ + opt->diffopt.output_prefix = diff_output_prefix_callback; + opt->diffopt.output_prefix_data = graph; + + return graph; +} + +static void graph_update_state(struct git_graph *graph, enum graph_state s) +{ + graph->prev_state = graph->state; + graph->state = s; +} + +static void graph_ensure_capacity(struct git_graph *graph, int num_columns) +{ + if (graph->column_capacity >= num_columns) + return; + + do { + graph->column_capacity *= 2; + } while (graph->column_capacity < num_columns); + + REALLOC_ARRAY(graph->columns, graph->column_capacity); + REALLOC_ARRAY(graph->new_columns, graph->column_capacity); + REALLOC_ARRAY(graph->mapping, graph->column_capacity * 2); + REALLOC_ARRAY(graph->old_mapping, graph->column_capacity * 2); +} + +/* + * Returns 1 if the commit will be printed in the graph output, + * and 0 otherwise. + */ +static int graph_is_interesting(struct git_graph *graph, struct commit *commit) +{ + /* + * If revs->boundary is set, commits whose children have + * been shown are always interesting, even if they have the + * UNINTERESTING or TREESAME flags set. + */ + if (graph->revs && graph->revs->boundary) { + if (commit->object.flags & CHILD_SHOWN) + return 1; + } + + /* + * Otherwise, use get_commit_action() to see if this commit is + * interesting + */ + return get_commit_action(graph->revs, commit) == commit_show; +} + +static struct commit_list *next_interesting_parent(struct git_graph *graph, + struct commit_list *orig) +{ + struct commit_list *list; + + /* + * If revs->first_parent_only is set, only the first + * parent is interesting. None of the others are. + */ + if (graph->revs->first_parent_only) + return NULL; + + /* + * Return the next interesting commit after orig + */ + for (list = orig->next; list; list = list->next) { + if (graph_is_interesting(graph, list->item)) + return list; + } + + return NULL; +} + +static struct commit_list *first_interesting_parent(struct git_graph *graph) +{ + struct commit_list *parents = graph->commit->parents; + + /* + * If this commit has no parents, ignore it + */ + if (!parents) + return NULL; + + /* + * If the first parent is interesting, return it + */ + if (graph_is_interesting(graph, parents->item)) + return parents; + + /* + * Otherwise, call next_interesting_parent() to get + * the next interesting parent + */ + return next_interesting_parent(graph, parents); +} + +static unsigned short graph_get_current_column_color(const struct git_graph *graph) +{ + if (!want_color(graph->revs->diffopt.use_color)) + return column_colors_max; + return graph->default_column_color; +} + +/* + * Update the graph's default column color. + */ +static void graph_increment_column_color(struct git_graph *graph) +{ + graph->default_column_color = (graph->default_column_color + 1) % + column_colors_max; +} + +static unsigned short graph_find_commit_color(const struct git_graph *graph, + const struct commit *commit) +{ + int i; + for (i = 0; i < graph->num_columns; i++) { + if (graph->columns[i].commit == commit) + return graph->columns[i].color; + } + return graph_get_current_column_color(graph); +} + +static int graph_find_new_column_by_commit(struct git_graph *graph, + struct commit *commit) +{ + int i; + for (i = 0; i < graph->num_new_columns; i++) { + if (graph->new_columns[i].commit == commit) + return i; + } + return -1; +} + +static void graph_insert_into_new_columns(struct git_graph *graph, + struct commit *commit, + int idx) +{ + int i = graph_find_new_column_by_commit(graph, commit); + int mapping_idx; + + /* + * If the commit is not already in the new_columns array, then add it + * and record it as being in the final column. + */ + if (i < 0) { + i = graph->num_new_columns++; + graph->new_columns[i].commit = commit; + graph->new_columns[i].color = graph_find_commit_color(graph, commit); + } + + if (graph->num_parents > 1 && idx > -1 && graph->merge_layout == -1) { + /* + * If this is the first parent of a merge, choose a layout for + * the merge line based on whether the parent appears in a + * column to the left of the merge + */ + int dist, shift; + + dist = idx - i; + shift = (dist > 1) ? 2 * dist - 3 : 1; + + graph->merge_layout = (dist > 0) ? 0 : 1; + graph->edges_added = graph->num_parents + graph->merge_layout - 2; + + mapping_idx = graph->width + (graph->merge_layout - 1) * shift; + graph->width += 2 * graph->merge_layout; + + } else if (graph->edges_added > 0 && i == graph->mapping[graph->width - 2]) { + /* + * If some columns have been added by a merge, but this commit + * was found in the last existing column, then adjust the + * numbers so that the two edges immediately join, i.e.: + * + * * | * | + * |\ \ => |\| + * | |/ | * + * | * + */ + mapping_idx = graph->width - 2; + graph->edges_added = -1; + } else { + mapping_idx = graph->width; + graph->width += 2; + } + + graph->mapping[mapping_idx] = i; +} + +static void graph_update_columns(struct git_graph *graph) +{ + struct commit_list *parent; + int max_new_columns; + int i, seen_this, is_commit_in_columns; + + /* + * Swap graph->columns with graph->new_columns + * graph->columns contains the state for the previous commit, + * and new_columns now contains the state for our commit. + * + * We'll re-use the old columns array as storage to compute the new + * columns list for the commit after this one. + */ + SWAP(graph->columns, graph->new_columns); + graph->num_columns = graph->num_new_columns; + graph->num_new_columns = 0; + + /* + * Now update new_columns and mapping with the information for the + * commit after this one. + * + * First, make sure we have enough room. At most, there will + * be graph->num_columns + graph->num_parents columns for the next + * commit. + */ + max_new_columns = graph->num_columns + graph->num_parents; + graph_ensure_capacity(graph, max_new_columns); + + /* + * Clear out graph->mapping + */ + graph->mapping_size = 2 * max_new_columns; + for (i = 0; i < graph->mapping_size; i++) + graph->mapping[i] = -1; + + graph->width = 0; + graph->prev_edges_added = graph->edges_added; + graph->edges_added = 0; + + /* + * Populate graph->new_columns and graph->mapping + * + * Some of the parents of this commit may already be in + * graph->columns. If so, graph->new_columns should only contain a + * single entry for each such commit. graph->mapping should + * contain information about where each current branch line is + * supposed to end up after the collapsing is performed. + */ + seen_this = 0; + is_commit_in_columns = 1; + for (i = 0; i <= graph->num_columns; i++) { + struct commit *col_commit; + if (i == graph->num_columns) { + if (seen_this) + break; + is_commit_in_columns = 0; + col_commit = graph->commit; + } else { + col_commit = graph->columns[i].commit; + } + + if (col_commit == graph->commit) { + seen_this = 1; + graph->commit_index = i; + graph->merge_layout = -1; + for (parent = first_interesting_parent(graph); + parent; + parent = next_interesting_parent(graph, parent)) { + /* + * If this is a merge, or the start of a new + * childless column, increment the current + * color. + */ + if (graph->num_parents > 1 || + !is_commit_in_columns) { + graph_increment_column_color(graph); + } + graph_insert_into_new_columns(graph, parent->item, i); + } + /* + * We always need to increment graph->width by at + * least 2, even if it has no interesting parents. + * The current commit always takes up at least 2 + * spaces. + */ + if (graph->num_parents == 0) + graph->width += 2; + } else { + graph_insert_into_new_columns(graph, col_commit, -1); + } + } + + /* + * Shrink mapping_size to be the minimum necessary + */ + while (graph->mapping_size > 1 && + graph->mapping[graph->mapping_size - 1] < 0) + graph->mapping_size--; +} + +static int graph_num_dashed_parents(struct git_graph *graph) +{ + return graph->num_parents + graph->merge_layout - 3; +} + +static int graph_num_expansion_rows(struct git_graph *graph) +{ + /* + * Normally, we need two expansion rows for each dashed parent line from + * an octopus merge: + * + * | * + * | |\ + * | | \ + * | | \ + * | *-. \ + * | |\ \ \ + * + * If the merge is skewed to the left, then its parents occupy one less + * column, and we don't need as many expansion rows to route around it; + * in some cases that means we don't need any expansion rows at all: + * + * | * + * | |\ + * | * \ + * |/|\ \ + */ + return graph_num_dashed_parents(graph) * 2; +} + +static int graph_needs_pre_commit_line(struct git_graph *graph) +{ + return graph->num_parents >= 3 && + graph->commit_index < (graph->num_columns - 1) && + graph->expansion_row < graph_num_expansion_rows(graph); +} + +void graph_update(struct git_graph *graph, struct commit *commit) +{ + struct commit_list *parent; + + /* + * Set the new commit + */ + graph->commit = commit; + + /* + * Count how many interesting parents this commit has + */ + graph->num_parents = 0; + for (parent = first_interesting_parent(graph); + parent; + parent = next_interesting_parent(graph, parent)) + { + graph->num_parents++; + } + + /* + * Store the old commit_index in prev_commit_index. + * graph_update_columns() will update graph->commit_index for this + * commit. + */ + graph->prev_commit_index = graph->commit_index; + + /* + * Call graph_update_columns() to update + * columns, new_columns, and mapping. + */ + graph_update_columns(graph); + + graph->expansion_row = 0; + + /* + * Update graph->state. + * Note that we don't call graph_update_state() here, since + * we don't want to update graph->prev_state. No line for + * graph->state was ever printed. + * + * If the previous commit didn't get to the GRAPH_PADDING state, + * it never finished its output. Goto GRAPH_SKIP, to print out + * a line to indicate that portion of the graph is missing. + * + * If there are 3 or more parents, we may need to print extra rows + * before the commit, to expand the branch lines around it and make + * room for it. We need to do this only if there is a branch row + * (or more) to the right of this commit. + * + * If there are less than 3 parents, we can immediately print the + * commit line. + */ + if (graph->state != GRAPH_PADDING) + graph->state = GRAPH_SKIP; + else if (graph_needs_pre_commit_line(graph)) + graph->state = GRAPH_PRE_COMMIT; + else + graph->state = GRAPH_COMMIT; +} + +static int graph_is_mapping_correct(struct git_graph *graph) +{ + int i; + + /* + * The mapping is up to date if each entry is at its target, + * or is 1 greater than its target. + * (If it is 1 greater than the target, '/' will be printed, so it + * will look correct on the next row.) + */ + for (i = 0; i < graph->mapping_size; i++) { + int target = graph->mapping[i]; + if (target < 0) + continue; + if (target == (i / 2)) + continue; + return 0; + } + + return 1; +} + +static void graph_pad_horizontally(struct git_graph *graph, struct graph_line *line) +{ + /* + * Add additional spaces to the end of the strbuf, so that all + * lines for a particular commit have the same width. + * + * This way, fields printed to the right of the graph will remain + * aligned for the entire commit. + */ + if (line->width < graph->width) + graph_line_addchars(line, ' ', graph->width - line->width); +} + +static void graph_output_padding_line(struct git_graph *graph, + struct graph_line *line) +{ + int i; + + /* + * Output a padding row, that leaves all branch lines unchanged + */ + for (i = 0; i < graph->num_new_columns; i++) { + graph_line_write_column(line, &graph->new_columns[i], '|'); + graph_line_addch(line, ' '); + } +} + + +int graph_width(struct git_graph *graph) +{ + return graph->width; +} + + +static void graph_output_skip_line(struct git_graph *graph, struct graph_line *line) +{ + /* + * Output an ellipsis to indicate that a portion + * of the graph is missing. + */ + graph_line_addstr(line, "..."); + + if (graph_needs_pre_commit_line(graph)) + graph_update_state(graph, GRAPH_PRE_COMMIT); + else + graph_update_state(graph, GRAPH_COMMIT); +} + +static void graph_output_pre_commit_line(struct git_graph *graph, + struct graph_line *line) +{ + int i, seen_this; + + /* + * This function formats a row that increases the space around a commit + * with multiple parents, to make room for it. It should only be + * called when there are 3 or more parents. + * + * We need 2 extra rows for every parent over 2. + */ + assert(graph->num_parents >= 3); + + /* + * graph->expansion_row tracks the current expansion row we are on. + * It should be in the range [0, num_expansion_rows - 1] + */ + assert(0 <= graph->expansion_row && + graph->expansion_row < graph_num_expansion_rows(graph)); + + /* + * Output the row + */ + seen_this = 0; + for (i = 0; i < graph->num_columns; i++) { + struct column *col = &graph->columns[i]; + if (col->commit == graph->commit) { + seen_this = 1; + graph_line_write_column(line, col, '|'); + graph_line_addchars(line, ' ', graph->expansion_row); + } else if (seen_this && (graph->expansion_row == 0)) { + /* + * This is the first line of the pre-commit output. + * If the previous commit was a merge commit and + * ended in the GRAPH_POST_MERGE state, all branch + * lines after graph->prev_commit_index were + * printed as "\" on the previous line. Continue + * to print them as "\" on this line. Otherwise, + * print the branch lines as "|". + */ + if (graph->prev_state == GRAPH_POST_MERGE && + graph->prev_commit_index < i) + graph_line_write_column(line, col, '\\'); + else + graph_line_write_column(line, col, '|'); + } else if (seen_this && (graph->expansion_row > 0)) { + graph_line_write_column(line, col, '\\'); + } else { + graph_line_write_column(line, col, '|'); + } + graph_line_addch(line, ' '); + } + + /* + * Increment graph->expansion_row, + * and move to state GRAPH_COMMIT if necessary + */ + graph->expansion_row++; + if (!graph_needs_pre_commit_line(graph)) + graph_update_state(graph, GRAPH_COMMIT); +} + +static void graph_output_commit_char(struct git_graph *graph, struct graph_line *line) +{ + /* + * For boundary commits, print 'o' + * (We should only see boundary commits when revs->boundary is set.) + */ + if (graph->commit->object.flags & BOUNDARY) { + assert(graph->revs->boundary); + graph_line_addch(line, 'o'); + return; + } + + /* + * get_revision_mark() handles all other cases without assert() + */ + graph_line_addstr(line, get_revision_mark(graph->revs, graph->commit)); +} + +/* + * Draw the horizontal dashes of an octopus merge. + */ +static void graph_draw_octopus_merge(struct git_graph *graph, struct graph_line *line) +{ + /* + * The parents of a merge commit can be arbitrarily reordered as they + * are mapped onto display columns, for example this is a valid merge: + * + * | | *---. + * | | |\ \ \ + * | | |/ / / + * | |/| | / + * | |_|_|/ + * |/| | | + * 3 1 0 2 + * + * The numbers denote which parent of the merge each visual column + * corresponds to; we can't assume that the parents will initially + * display in the order given by new_columns. + * + * To find the right color for each dash, we need to consult the + * mapping array, starting from the column 2 places to the right of the + * merge commit, and use that to find out which logical column each + * edge will collapse to. + * + * Commits are rendered once all edges have collapsed to their correct + * logcial column, so commit_index gives us the right visual offset for + * the merge commit. + */ + + int i, j; + struct column *col; + + int dashed_parents = graph_num_dashed_parents(graph); + + for (i = 0; i < dashed_parents; i++) { + j = graph->mapping[(graph->commit_index + i + 2) * 2]; + col = &graph->new_columns[j]; + + graph_line_write_column(line, col, '-'); + graph_line_write_column(line, col, (i == dashed_parents - 1) ? '.' : '-'); + } + + return; +} + +static void graph_output_commit_line(struct git_graph *graph, struct graph_line *line) +{ + int seen_this = 0; + int i; + + /* + * Output the row containing this commit + * Iterate up to and including graph->num_columns, + * since the current commit may not be in any of the existing + * columns. (This happens when the current commit doesn't have any + * children that we have already processed.) + */ + seen_this = 0; + for (i = 0; i <= graph->num_columns; i++) { + struct column *col = &graph->columns[i]; + struct commit *col_commit; + if (i == graph->num_columns) { + if (seen_this) + break; + col_commit = graph->commit; + } else { + col_commit = graph->columns[i].commit; + } + + if (col_commit == graph->commit) { + seen_this = 1; + graph_output_commit_char(graph, line); + + if (graph->num_parents > 2) + graph_draw_octopus_merge(graph, line); + } else if (seen_this && (graph->edges_added > 1)) { + graph_line_write_column(line, col, '\\'); + } else if (seen_this && (graph->edges_added == 1)) { + /* + * This is either a right-skewed 2-way merge + * commit, or a left-skewed 3-way merge. + * There is no GRAPH_PRE_COMMIT stage for such + * merges, so this is the first line of output + * for this commit. Check to see what the previous + * line of output was. + * + * If it was GRAPH_POST_MERGE, the branch line + * coming into this commit may have been '\', + * and not '|' or '/'. If so, output the branch + * line as '\' on this line, instead of '|'. This + * makes the output look nicer. + */ + if (graph->prev_state == GRAPH_POST_MERGE && + graph->prev_edges_added > 0 && + graph->prev_commit_index < i) + graph_line_write_column(line, col, '\\'); + else + graph_line_write_column(line, col, '|'); + } else if (graph->prev_state == GRAPH_COLLAPSING && + graph->old_mapping[2 * i + 1] == i && + graph->mapping[2 * i] < i) { + graph_line_write_column(line, col, '/'); + } else { + graph_line_write_column(line, col, '|'); + } + graph_line_addch(line, ' '); + } + + /* + * Update graph->state + */ + if (graph->num_parents > 1) + graph_update_state(graph, GRAPH_POST_MERGE); + else if (graph_is_mapping_correct(graph)) + graph_update_state(graph, GRAPH_PADDING); + else + graph_update_state(graph, GRAPH_COLLAPSING); +} + +const char merge_chars[] = {'/', '|', '\\'}; + +static void graph_output_post_merge_line(struct git_graph *graph, struct graph_line *line) +{ + int seen_this = 0; + int i, j; + + struct commit_list *first_parent = first_interesting_parent(graph); + struct column *parent_col = NULL; + + /* + * Output the post-merge row + */ + for (i = 0; i <= graph->num_columns; i++) { + struct column *col = &graph->columns[i]; + struct commit *col_commit; + if (i == graph->num_columns) { + if (seen_this) + break; + col_commit = graph->commit; + } else { + col_commit = col->commit; + } + + if (col_commit == graph->commit) { + /* + * Since the current commit is a merge find + * the columns for the parent commits in + * new_columns and use those to format the + * edges. + */ + struct commit_list *parents = first_parent; + int par_column; + int idx = graph->merge_layout; + char c; + seen_this = 1; + + for (j = 0; j < graph->num_parents; j++) { + par_column = graph_find_new_column_by_commit(graph, parents->item); + assert(par_column >= 0); + + c = merge_chars[idx]; + graph_line_write_column(line, &graph->new_columns[par_column], c); + if (idx == 2) { + if (graph->edges_added > 0 || j < graph->num_parents - 1) + graph_line_addch(line, ' '); + } else { + idx++; + } + parents = next_interesting_parent(graph, parents); + } + if (graph->edges_added == 0) + graph_line_addch(line, ' '); + + } else if (seen_this) { + if (graph->edges_added > 0) + graph_line_write_column(line, col, '\\'); + else + graph_line_write_column(line, col, '|'); + graph_line_addch(line, ' '); + } else { + graph_line_write_column(line, col, '|'); + if (graph->merge_layout != 0 || i != graph->commit_index - 1) { + if (parent_col) + graph_line_write_column( + line, parent_col, '_'); + else + graph_line_addch(line, ' '); + } + } + + if (col_commit == first_parent->item) + parent_col = col; + } + + /* + * Update graph->state + */ + if (graph_is_mapping_correct(graph)) + graph_update_state(graph, GRAPH_PADDING); + else + graph_update_state(graph, GRAPH_COLLAPSING); +} + +static void graph_output_collapsing_line(struct git_graph *graph, struct graph_line *line) +{ + int i; + short used_horizontal = 0; + int horizontal_edge = -1; + int horizontal_edge_target = -1; + + /* + * Swap the mapping and old_mapping arrays + */ + SWAP(graph->mapping, graph->old_mapping); + + /* + * Clear out the mapping array + */ + for (i = 0; i < graph->mapping_size; i++) + graph->mapping[i] = -1; + + for (i = 0; i < graph->mapping_size; i++) { + int target = graph->old_mapping[i]; + if (target < 0) + continue; + + /* + * Since update_columns() always inserts the leftmost + * column first, each branch's target location should + * always be either its current location or to the left of + * its current location. + * + * We never have to move branches to the right. This makes + * the graph much more legible, since whenever branches + * cross, only one is moving directions. + */ + assert(target * 2 <= i); + + if (target * 2 == i) { + /* + * This column is already in the + * correct place + */ + assert(graph->mapping[i] == -1); + graph->mapping[i] = target; + } else if (graph->mapping[i - 1] < 0) { + /* + * Nothing is to the left. + * Move to the left by one + */ + graph->mapping[i - 1] = target; + /* + * If there isn't already an edge moving horizontally + * select this one. + */ + if (horizontal_edge == -1) { + int j; + horizontal_edge = i; + horizontal_edge_target = target; + /* + * The variable target is the index of the graph + * column, and therefore target*2+3 is the + * actual screen column of the first horizontal + * line. + */ + for (j = (target * 2)+3; j < (i - 2); j += 2) + graph->mapping[j] = target; + } + } else if (graph->mapping[i - 1] == target) { + /* + * There is a branch line to our left + * already, and it is our target. We + * combine with this line, since we share + * the same parent commit. + * + * We don't have to add anything to the + * output or mapping, since the + * existing branch line has already taken + * care of it. + */ + } else { + /* + * There is a branch line to our left, + * but it isn't our target. We need to + * cross over it. + * + * The space just to the left of this + * branch should always be empty. + */ + assert(graph->mapping[i - 1] > target); + assert(graph->mapping[i - 2] < 0); + graph->mapping[i - 2] = target; + /* + * Mark this branch as the horizontal edge to + * prevent any other edges from moving + * horizontally. + */ + if (horizontal_edge == -1) { + int j; + horizontal_edge_target = target; + horizontal_edge = i - 1; + + for (j = (target * 2) + 3; j < (i - 2); j += 2) + graph->mapping[j] = target; + } + } + } + + /* + * Copy the current mapping array into old_mapping + */ + COPY_ARRAY(graph->old_mapping, graph->mapping, graph->mapping_size); + + /* + * The new mapping may be 1 smaller than the old mapping + */ + if (graph->mapping[graph->mapping_size - 1] < 0) + graph->mapping_size--; + + /* + * Output out a line based on the new mapping info + */ + for (i = 0; i < graph->mapping_size; i++) { + int target = graph->mapping[i]; + if (target < 0) + graph_line_addch(line, ' '); + else if (target * 2 == i) + graph_line_write_column(line, &graph->new_columns[target], '|'); + else if (target == horizontal_edge_target && + i != horizontal_edge - 1) { + /* + * Set the mappings for all but the + * first segment to -1 so that they + * won't continue into the next line. + */ + if (i != (target * 2)+3) + graph->mapping[i] = -1; + used_horizontal = 1; + graph_line_write_column(line, &graph->new_columns[target], '_'); + } else { + if (used_horizontal && i < horizontal_edge) + graph->mapping[i] = -1; + graph_line_write_column(line, &graph->new_columns[target], '/'); + + } + } + + /* + * If graph->mapping indicates that all of the branch lines + * are already in the correct positions, we are done. + * Otherwise, we need to collapse some branch lines together. + */ + if (graph_is_mapping_correct(graph)) + graph_update_state(graph, GRAPH_PADDING); +} + +int graph_next_line(struct git_graph *graph, struct strbuf *sb) +{ + int shown_commit_line = 0; + struct graph_line line = { .buf = sb, .width = 0 }; + + /* + * We could conceivable be called with a NULL commit + * if our caller has a bug, and invokes graph_next_line() + * immediately after graph_init(), without first calling + * graph_update(). Return without outputting anything in this + * case. + */ + if (!graph->commit) + return -1; + + switch (graph->state) { + case GRAPH_PADDING: + graph_output_padding_line(graph, &line); + break; + case GRAPH_SKIP: + graph_output_skip_line(graph, &line); + break; + case GRAPH_PRE_COMMIT: + graph_output_pre_commit_line(graph, &line); + break; + case GRAPH_COMMIT: + graph_output_commit_line(graph, &line); + shown_commit_line = 1; + break; + case GRAPH_POST_MERGE: + graph_output_post_merge_line(graph, &line); + break; + case GRAPH_COLLAPSING: + graph_output_collapsing_line(graph, &line); + break; + } + + graph_pad_horizontally(graph, &line); + return shown_commit_line; +} + +static void graph_padding_line(struct git_graph *graph, struct strbuf *sb) +{ + int i; + struct graph_line line = { .buf = sb, .width = 0 }; + + if (graph->state != GRAPH_COMMIT) { + graph_next_line(graph, sb); + return; + } + + /* + * Output the row containing this commit + * Iterate up to and including graph->num_columns, + * since the current commit may not be in any of the existing + * columns. (This happens when the current commit doesn't have any + * children that we have already processed.) + */ + for (i = 0; i < graph->num_columns; i++) { + struct column *col = &graph->columns[i]; + + graph_line_write_column(&line, col, '|'); + + if (col->commit == graph->commit && graph->num_parents > 2) { + int len = (graph->num_parents - 2) * 2; + graph_line_addchars(&line, ' ', len); + } else { + graph_line_addch(&line, ' '); + } + } + + graph_pad_horizontally(graph, &line); + + /* + * Update graph->prev_state since we have output a padding line + */ + graph->prev_state = GRAPH_PADDING; +} + +int graph_is_commit_finished(struct git_graph const *graph) +{ + return (graph->state == GRAPH_PADDING); +} + +void graph_show_commit(struct git_graph *graph) +{ + struct strbuf msgbuf = STRBUF_INIT; + int shown_commit_line = 0; + + graph_show_line_prefix(default_diffopt); + + if (!graph) + return; + + /* + * When showing a diff of a merge against each of its parents, we + * are called once for each parent without graph_update having been + * called. In this case, simply output a single padding line. + */ + if (graph_is_commit_finished(graph)) { + graph_show_padding(graph); + shown_commit_line = 1; + } + + while (!shown_commit_line && !graph_is_commit_finished(graph)) { + shown_commit_line = graph_next_line(graph, &msgbuf); + fwrite(msgbuf.buf, sizeof(char), msgbuf.len, + graph->revs->diffopt.file); + if (!shown_commit_line) { + putc('\n', graph->revs->diffopt.file); + graph_show_line_prefix(&graph->revs->diffopt); + } + strbuf_setlen(&msgbuf, 0); + } + + strbuf_release(&msgbuf); +} + +void graph_show_oneline(struct git_graph *graph) +{ + struct strbuf msgbuf = STRBUF_INIT; + + graph_show_line_prefix(default_diffopt); + + if (!graph) + return; + + graph_next_line(graph, &msgbuf); + fwrite(msgbuf.buf, sizeof(char), msgbuf.len, graph->revs->diffopt.file); + strbuf_release(&msgbuf); +} + +void graph_show_padding(struct git_graph *graph) +{ + struct strbuf msgbuf = STRBUF_INIT; + + graph_show_line_prefix(default_diffopt); + + if (!graph) + return; + + graph_padding_line(graph, &msgbuf); + fwrite(msgbuf.buf, sizeof(char), msgbuf.len, graph->revs->diffopt.file); + strbuf_release(&msgbuf); +} + +int graph_show_remainder(struct git_graph *graph) +{ + struct strbuf msgbuf = STRBUF_INIT; + int shown = 0; + + graph_show_line_prefix(default_diffopt); + + if (!graph) + return 0; + + if (graph_is_commit_finished(graph)) + return 0; + + for (;;) { + graph_next_line(graph, &msgbuf); + fwrite(msgbuf.buf, sizeof(char), msgbuf.len, + graph->revs->diffopt.file); + strbuf_setlen(&msgbuf, 0); + shown = 1; + + if (!graph_is_commit_finished(graph)) { + putc('\n', graph->revs->diffopt.file); + graph_show_line_prefix(&graph->revs->diffopt); + } else { + break; + } + } + strbuf_release(&msgbuf); + + return shown; +} + +static void graph_show_strbuf(struct git_graph *graph, + FILE *file, + struct strbuf const *sb) +{ + char *p; + + /* + * Print the strbuf line by line, + * and display the graph info before each line but the first. + */ + p = sb->buf; + while (p) { + size_t len; + char *next_p = strchr(p, '\n'); + if (next_p) { + next_p++; + len = next_p - p; + } else { + len = (sb->buf + sb->len) - p; + } + fwrite(p, sizeof(char), len, file); + if (next_p && *next_p != '\0') + graph_show_oneline(graph); + p = next_p; + } +} + +void graph_show_commit_msg(struct git_graph *graph, + FILE *file, + struct strbuf const *sb) +{ + int newline_terminated; + + /* + * Show the commit message + */ + graph_show_strbuf(graph, file, sb); + + if (!graph) + return; + + newline_terminated = (sb->len && sb->buf[sb->len - 1] == '\n'); + + /* + * If there is more output needed for this commit, show it now + */ + if (!graph_is_commit_finished(graph)) { + /* + * If sb doesn't have a terminating newline, print one now, + * so we can start the remainder of the graph output on a + * new line. + */ + if (!newline_terminated) + putc('\n', file); + + graph_show_remainder(graph); + + /* + * If sb ends with a newline, our output should too. + */ + if (newline_terminated) + putc('\n', file); + } +} |