fmt-merge-msg: refactor merge title formatting
[gitweb.git] / graph.c
diff --git a/graph.c b/graph.c
index 162a516ee15cca1f8ab118dd41b803a5d76e42ff..e6bbcaa8c4655add3ecaca578e948355795e36ca 100644 (file)
--- a/graph.c
+++ b/graph.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "commit.h"
+#include "color.h"
 #include "graph.h"
 #include "diff.h"
 #include "revision.h"
@@ -34,7 +35,7 @@ static void graph_padding_line(struct git_graph *graph, struct strbuf *sb);
  * 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 ouput, the caller is
+ * 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().
@@ -43,27 +44,9 @@ static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb);
 
 /*
  * TODO:
- * - Add colors to the graph.
- *   Pick a color for each column, and print all characters
- *   in that column with the specified color.
- *
  * - 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.
- *
- * - The output during the GRAPH_PRE_COMMIT and GRAPH_COLLAPSING states
- *   could be made more compact by printing horizontal lines, instead of
- *   long diagonal lines.  For example, during collapsing, something like
- *   this:          instead of this:
- *   | | | | |      | | | | |
- *   | |_|_|/       | | | |/
- *   |/| | |        | | |/|
- *   | | | |        | |/| |
- *                  |/| | |
- *                  | | | |
- *
- *   If there are several parallel diagonal lines, they will need to be
- *   replaced with horizontal lines on subsequent rows.
  */
 
 struct column {
@@ -72,9 +55,10 @@ struct column {
         */
        struct commit *commit;
        /*
-        * XXX: Once we add support for colors, struct column could also
-        * contain the color of its branch line.
+        * The color to (optionally) print this column in.  This is an
+        * index into column_colors.
         */
+       unsigned short color;
 };
 
 enum graph_state {
@@ -86,6 +70,41 @@ enum graph_state {
        GRAPH_COLLAPSING
 };
 
+/*
+ * The list of available column colors.
+ */
+static char column_colors[][COLOR_MAXLEN] = {
+       GIT_COLOR_RED,
+       GIT_COLOR_GREEN,
+       GIT_COLOR_YELLOW,
+       GIT_COLOR_BLUE,
+       GIT_COLOR_MAGENTA,
+       GIT_COLOR_CYAN,
+       GIT_COLOR_BOLD_RED,
+       GIT_COLOR_BOLD_GREEN,
+       GIT_COLOR_BOLD_YELLOW,
+       GIT_COLOR_BOLD_BLUE,
+       GIT_COLOR_BOLD_MAGENTA,
+       GIT_COLOR_BOLD_CYAN,
+};
+
+#define COLUMN_COLORS_MAX (ARRAY_SIZE(column_colors))
+
+static const char *column_get_color_code(const struct column *c)
+{
+       return column_colors[c->color];
+}
+
+static void strbuf_write_column(struct strbuf *sb, const struct column *c,
+                               char col_char)
+{
+       if (c->color < COLUMN_COLORS_MAX)
+               strbuf_addstr(sb, column_get_color_code(c));
+       strbuf_addch(sb, col_char);
+       if (c->color < COLUMN_COLORS_MAX)
+               strbuf_addstr(sb, GIT_COLOR_RESET);
+}
+
 struct git_graph {
        /*
         * The commit currently being processed
@@ -185,6 +204,11 @@ struct git_graph {
         * temporary array each time we have to output a collapsing line.
         */
        int *new_mapping;
+       /*
+        * The current default column color being used.  This is
+        * stored as an index into the array column_colors.
+        */
+       unsigned short default_column_color;
 };
 
 struct git_graph *graph_init(struct rev_info *opt)
@@ -201,6 +225,12 @@ struct git_graph *graph_init(struct rev_info *opt)
        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
@@ -261,9 +291,10 @@ static int graph_is_interesting(struct git_graph *graph, struct commit *commit)
        }
 
        /*
-        * Uninteresting and pruned commits won't be printed
+        * Otherwise, use get_commit_action() to see if this commit is
+        * interesting
         */
-       return (commit->object.flags & (UNINTERESTING | TREESAME)) ? 0 : 1;
+       return get_commit_action(graph->revs, commit) == commit_show;
 }
 
 static struct commit_list *next_interesting_parent(struct git_graph *graph,
@@ -312,6 +343,33 @@ static struct commit_list *first_interesting_parent(struct git_graph *graph)
        return next_interesting_parent(graph, parents);
 }
 
+static unsigned short graph_get_current_column_color(const struct git_graph *graph)
+{
+       if (!DIFF_OPT_TST(&graph->revs->diffopt, COLOR_DIFF))
+               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 void graph_insert_into_new_columns(struct git_graph *graph,
                                          struct commit *commit,
                                          int *mapping_index)
@@ -334,6 +392,7 @@ static void graph_insert_into_new_columns(struct git_graph *graph,
         * This commit isn't already in new_columns.  Add it.
         */
        graph->new_columns[graph->num_new_columns].commit = commit;
+       graph->new_columns[graph->num_new_columns].color = graph_find_commit_color(graph, commit);
        graph->mapping[*mapping_index] = graph->num_new_columns;
        *mapping_index += 2;
        graph->num_new_columns++;
@@ -445,6 +504,15 @@ static void graph_update_columns(struct git_graph *graph)
                        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,
                                                              &mapping_idx);
@@ -560,7 +628,8 @@ static int graph_is_mapping_correct(struct git_graph *graph)
        return 1;
 }
 
-static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb)
+static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb,
+                                  int chars_written)
 {
        /*
         * Add additional spaces to the end of the strbuf, so that all
@@ -570,10 +639,10 @@ static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb)
         * aligned for the entire commit.
         */
        int extra;
-       if (sb->len >= graph->width)
+       if (chars_written >= graph->width)
                return;
 
-       extra = graph->width - sb->len;
+       extra = graph->width - chars_written;
        strbuf_addf(sb, "%*s", (int) extra, "");
 }
 
@@ -596,10 +665,11 @@ static void graph_output_padding_line(struct git_graph *graph,
         * Output a padding row, that leaves all branch lines unchanged
         */
        for (i = 0; i < graph->num_new_columns; i++) {
-               strbuf_addstr(sb, "| ");
+               strbuf_write_column(sb, &graph->new_columns[i], '|');
+               strbuf_addch(sb, ' ');
        }
 
-       graph_pad_horizontally(graph, sb);
+       graph_pad_horizontally(graph, sb, graph->num_new_columns * 2);
 }
 
 static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
@@ -609,7 +679,7 @@ static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
         * of the graph is missing.
         */
        strbuf_addstr(sb, "...");
-       graph_pad_horizontally(graph, sb);
+       graph_pad_horizontally(graph, sb, 3);
 
        if (graph->num_parents >= 3 &&
            graph->commit_index < (graph->num_columns - 1))
@@ -623,6 +693,7 @@ static void graph_output_pre_commit_line(struct git_graph *graph,
 {
        int num_expansion_rows;
        int i, seen_this;
+       int chars_written;
 
        /*
         * This function formats a row that increases the space around a commit
@@ -645,11 +716,14 @@ static void graph_output_pre_commit_line(struct git_graph *graph,
         * Output the row
         */
        seen_this = 0;
+       chars_written = 0;
        for (i = 0; i < graph->num_columns; i++) {
                struct column *col = &graph->columns[i];
                if (col->commit == graph->commit) {
                        seen_this = 1;
-                       strbuf_addf(sb, "| %*s", graph->expansion_row, "");
+                       strbuf_write_column(sb, col, '|');
+                       strbuf_addf(sb, "%*s", graph->expansion_row, "");
+                       chars_written += 1 + graph->expansion_row;
                } else if (seen_this && (graph->expansion_row == 0)) {
                        /*
                         * This is the first line of the pre-commit output.
@@ -662,17 +736,22 @@ static void graph_output_pre_commit_line(struct git_graph *graph,
                         */
                        if (graph->prev_state == GRAPH_POST_MERGE &&
                            graph->prev_commit_index < i)
-                               strbuf_addstr(sb, "\\ ");
+                               strbuf_write_column(sb, col, '\\');
                        else
-                               strbuf_addstr(sb, "| ");
+                               strbuf_write_column(sb, col, '|');
+                       chars_written++;
                } else if (seen_this && (graph->expansion_row > 0)) {
-                       strbuf_addstr(sb, "\\ ");
+                       strbuf_write_column(sb, col, '\\');
+                       chars_written++;
                } else {
-                       strbuf_addstr(sb, "| ");
+                       strbuf_write_column(sb, col, '|');
+                       chars_written++;
                }
+               strbuf_addch(sb, ' ');
+               chars_written++;
        }
 
-       graph_pad_horizontally(graph, sb);
+       graph_pad_horizontally(graph, sb, chars_written);
 
        /*
         * Increment graph->expansion_row,
@@ -714,10 +793,34 @@ static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
        strbuf_addch(sb, '*');
 }
 
+/*
+ * Draw an octopus merge and return the number of characters written.
+ */
+static int graph_draw_octopus_merge(struct git_graph *graph,
+                                   struct strbuf *sb)
+{
+       /*
+        * Here dashless_commits represents the number of parents
+        * which don't need to have dashes (because their edges fit
+        * neatly under the commit).
+        */
+       const int dashless_commits = 2;
+       int col_num, i;
+       int num_dashes =
+               ((graph->num_parents - dashless_commits) * 2) - 1;
+       for (i = 0; i < num_dashes; i++) {
+               col_num = (i / 2) + dashless_commits;
+               strbuf_write_column(sb, &graph->new_columns[col_num], '-');
+       }
+       col_num = (i / 2) + dashless_commits;
+       strbuf_write_column(sb, &graph->new_columns[col_num], '.');
+       return num_dashes + 1;
+}
+
 static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
 {
        int seen_this = 0;
-       int i, j;
+       int i, chars_written;
 
        /*
         * Output the row containing this commit
@@ -727,7 +830,9 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
         * children that we have already processed.)
         */
        seen_this = 0;
+       chars_written = 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)
@@ -740,18 +845,14 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
                if (col_commit == graph->commit) {
                        seen_this = 1;
                        graph_output_commit_char(graph, sb);
+                       chars_written++;
 
-                       if (graph->num_parents < 3)
-                               strbuf_addch(sb, ' ');
-                       else {
-                               int num_dashes =
-                                       ((graph->num_parents - 2) * 2) - 1;
-                               for (j = 0; j < num_dashes; j++)
-                                       strbuf_addch(sb, '-');
-                               strbuf_addstr(sb, ". ");
-                       }
+                       if (graph->num_parents > 2)
+                               chars_written += graph_draw_octopus_merge(graph,
+                                                                         sb);
                } else if (seen_this && (graph->num_parents > 2)) {
-                       strbuf_addstr(sb, "\\ ");
+                       strbuf_write_column(sb, col, '\\');
+                       chars_written++;
                } else if (seen_this && (graph->num_parents == 2)) {
                        /*
                         * This is a 2-way merge commit.
@@ -768,15 +869,19 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
                         */
                        if (graph->prev_state == GRAPH_POST_MERGE &&
                            graph->prev_commit_index < i)
-                               strbuf_addstr(sb, "\\ ");
+                               strbuf_write_column(sb, col, '\\');
                        else
-                               strbuf_addstr(sb, "| ");
+                               strbuf_write_column(sb, col, '|');
+                       chars_written++;
                } else {
-                       strbuf_addstr(sb, "| ");
+                       strbuf_write_column(sb, col, '|');
+                       chars_written++;
                }
+               strbuf_addch(sb, ' ');
+               chars_written++;
        }
 
-       graph_pad_horizontally(graph, sb);
+       graph_pad_horizontally(graph, sb, chars_written);
 
        /*
         * Update graph->state
@@ -789,37 +894,75 @@ static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
                graph_update_state(graph, GRAPH_COLLAPSING);
 }
 
+static struct column *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 &graph->new_columns[i];
+       }
+       return NULL;
+}
+
 static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
 {
        int seen_this = 0;
-       int i, j;
+       int i, j, chars_written;
 
        /*
         * Output the post-merge row
         */
+       chars_written = 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;
+                       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 = NULL;
+                       struct column *par_column;
                        seen_this = 1;
-                       strbuf_addch(sb, '|');
-                       for (j = 0; j < graph->num_parents - 1; j++)
-                               strbuf_addstr(sb, "\\ ");
+                       parents = first_interesting_parent(graph);
+                       assert(parents);
+                       par_column = find_new_column_by_commit(graph, parents->item);
+                       assert(par_column);
+
+                       strbuf_write_column(sb, par_column, '|');
+                       chars_written++;
+                       for (j = 0; j < graph->num_parents - 1; j++) {
+                               parents = next_interesting_parent(graph, parents);
+                               assert(parents);
+                               par_column = find_new_column_by_commit(graph, parents->item);
+                               assert(par_column);
+                               strbuf_write_column(sb, par_column, '\\');
+                               strbuf_addch(sb, ' ');
+                       }
+                       chars_written += j * 2;
                } else if (seen_this) {
-                       strbuf_addstr(sb, "\\ ");
+                       strbuf_write_column(sb, col, '\\');
+                       strbuf_addch(sb, ' ');
+                       chars_written += 2;
                } else {
-                       strbuf_addstr(sb, "| ");
+                       strbuf_write_column(sb, col, '|');
+                       strbuf_addch(sb, ' ');
+                       chars_written += 2;
                }
        }
 
-       graph_pad_horizontally(graph, sb);
+       graph_pad_horizontally(graph, sb, chars_written);
 
        /*
         * Update graph->state
@@ -834,6 +977,9 @@ static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf
 {
        int i;
        int *tmp_mapping;
+       short used_horizontal = 0;
+       int horizontal_edge = -1;
+       int horizontal_edge_target = -1;
 
        /*
         * Clear out the new_mapping array
@@ -871,6 +1017,23 @@ static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf
                         * Move to the left by one
                         */
                        graph->new_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->new_mapping[j] = target;
+                       }
                } else if (graph->new_mapping[i - 1] == target) {
                        /*
                         * There is a branch line to our left
@@ -891,10 +1054,21 @@ static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf
                         *
                         * The space just to the left of this
                         * branch should always be empty.
+                        *
+                        * The branch to the left of that space
+                        * should be our eventual target.
                         */
                        assert(graph->new_mapping[i - 1] > target);
                        assert(graph->new_mapping[i - 2] < 0);
+                       assert(graph->new_mapping[i - 3] == target);
                        graph->new_mapping[i - 2] = target;
+                       /*
+                        * Mark this branch as the horizontal edge to
+                        * prevent any other edges from moving
+                        * horizontally.
+                        */
+                       if (horizontal_edge == -1)
+                               horizontal_edge = i;
                }
        }
 
@@ -912,12 +1086,27 @@ static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf
                if (target < 0)
                        strbuf_addch(sb, ' ');
                else if (target * 2 == i)
-                       strbuf_addch(sb, '|');
-               else
-                       strbuf_addch(sb, '/');
+                       strbuf_write_column(sb, &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->new_mapping[i] = -1;
+                               used_horizontal = 1;
+                       strbuf_write_column(sb, &graph->new_columns[target], '_');
+               } else {
+                       if (used_horizontal && i < horizontal_edge)
+                               graph->new_mapping[i] = -1;
+                       strbuf_write_column(sb, &graph->new_columns[target], '/');
+
+               }
        }
 
-       graph_pad_horizontally(graph, sb);
+       graph_pad_horizontally(graph, sb, graph->mapping_size);
 
        /*
         * Swap mapping and new_mapping
@@ -979,9 +1168,10 @@ static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
         * children that we have already processed.)
         */
        for (i = 0; i < graph->num_columns; i++) {
-               struct commit *col_commit = graph->columns[i].commit;
+               struct column *col = &graph->columns[i];
+               struct commit *col_commit = col->commit;
                if (col_commit == graph->commit) {
-                       strbuf_addch(sb, '|');
+                       strbuf_write_column(sb, col, '|');
 
                        if (graph->num_parents < 3)
                                strbuf_addch(sb, ' ');
@@ -991,11 +1181,12 @@ static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
                                        strbuf_addch(sb, ' ');
                        }
                } else {
-                       strbuf_addstr(sb, "| ");
+                       strbuf_write_column(sb, col, '|');
+                       strbuf_addch(sb, ' ');
                }
        }
 
-       graph_pad_horizontally(graph, sb);
+       graph_pad_horizontally(graph, sb, graph->num_columns);
 
        /*
         * Update graph->prev_state since we have output a padding line