graph API: Added logic for colored edges
[git/git.git] / graph.c
diff --git a/graph.c b/graph.c
index 162a516..d4571cf 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"
@@ -43,10 +44,6 @@ 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.
@@ -72,9 +69,10 @@ 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 +84,41 @@ 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 GIT_COLOR_RED,
+       GIT_COLOR_BOLD GIT_COLOR_GREEN,
+       GIT_COLOR_BOLD GIT_COLOR_YELLOW,
+       GIT_COLOR_BOLD GIT_COLOR_BLUE,
+       GIT_COLOR_BOLD GIT_COLOR_MAGENTA,
+       GIT_COLOR_BOLD GIT_COLOR_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 +218,11 @@ 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 +239,7 @@ struct git_graph *graph_init(struct rev_info *opt)
        graph->num_columns = 0;
        graph->num_new_columns = 0;
        graph->mapping_size = 0;
+       graph->default_column_color = 0;
 
        /*
         * Allocate a reasonably large default number of columns
@@ -312,6 +351,33 @@ 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 +400,7 @@ 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 +512,12 @@ 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 increment the current
+                                * color.
+                                */
+                               if (graph->num_parents > 1)
+                                       graph_increment_column_color(graph);
                                graph_insert_into_new_columns(graph,
                                                              parent->item,
                                                              &mapping_idx);
@@ -560,7 +633,8 @@ 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 +644,10 @@ 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 +670,11 @@ 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 +684,7 @@ 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 +698,7 @@ 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 +721,14 @@ 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 += 2 + graph->expansion_row;
                } else if (seen_this && (graph->expansion_row == 0)) {
                        /*
                         * This is the first line of the pre-commit output.
@@ -662,17 +741,22 @@ 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 +798,34 @@ 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 +835,9 @@ 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 +850,14 @@ 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 > 3)
+                               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 +874,19 @@ 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 +899,75 @@ 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 0;
+}
+
 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
@@ -912,12 +1060,12 @@ 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, '|');
+                       strbuf_write_column(sb, &graph->new_columns[target], '|');
                else
-                       strbuf_addch(sb, '/');
+                       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 +1127,10 @@ 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 +1140,12 @@ 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