Teach git diff about Objective-C syntax
[gitweb.git] / graph.c
diff --git a/graph.c b/graph.c
index 616e18b13f496cd97bce5333b6c7655ae3cfa2f0..5f821706c63778e8b6b53a10894edfc2fb21a8b0 100644 (file)
--- a/graph.c
+++ b/graph.c
@@ -4,6 +4,43 @@
 #include "diff.h"
 #include "revision.h"
 
+/* Internal API */
+
+/*
+ * Output the next line for a graph.
+ * This formats the next graph line into the specified strbuf.  It is not
+ * terminated with a newline.
+ *
+ * Returns 1 if the line includes the current commit, and 0 otherwise.
+ * graph_next_line() will return 1 exactly once for each time
+ * graph_update() is called.
+ */
+static int graph_next_line(struct git_graph *graph, struct strbuf *sb);
+
+/*
+ * 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 to stdout.  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 ouput, the caller is
+ * responsible for printing this line's graph (perhaps via
+ * graph_show_commit() or graph_show_oneline()) before calling
+ * graph_show_strbuf().
+ */
+static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb);
+
 /*
  * TODO:
  * - Add colors to the graph.
@@ -54,12 +91,22 @@ 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 parents this commit has.
-        * (Stored so we don't have to walk over them each time we need
-        * this number)
+        * 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
@@ -70,6 +117,27 @@ struct git_graph {
         * 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;
        /*
         * The maximum number of columns that can be stored in the columns
         * and new_columns arrays.  This is also half the number of entries
@@ -119,13 +187,17 @@ struct git_graph {
        int *new_mapping;
 };
 
-struct git_graph *graph_init(void)
+struct git_graph *graph_init(struct rev_info *opt)
 {
        struct git_graph *graph = xmalloc(sizeof(struct git_graph));
        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->num_columns = 0;
        graph->num_new_columns = 0;
        graph->mapping_size = 0;
@@ -145,12 +217,10 @@ struct git_graph *graph_init(void)
        return graph;
 }
 
-void graph_release(struct git_graph *graph)
+static void graph_update_state(struct git_graph *graph, enum graph_state s)
 {
-       free(graph->columns);
-       free(graph->new_columns);
-       free(graph->mapping);
-       free(graph);
+       graph->prev_state = graph->state;
+       graph->state = s;
 }
 
 static void graph_ensure_capacity(struct git_graph *graph, int num_columns)
@@ -174,18 +244,80 @@ static void graph_ensure_capacity(struct git_graph *graph, int num_columns)
                                      sizeof(int) * 2 * graph->column_capacity);
 }
 
+/*
+ * 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;
+       }
+
+       /*
+        * Uninteresting and pruned commits won't be printed
+        */
+       return (commit->object.flags & (UNINTERESTING | TREESAME)) ? 0 : 1;
+}
+
+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 void graph_insert_into_new_columns(struct git_graph *graph,
                                          struct commit *commit,
                                          int *mapping_index)
 {
        int i;
 
-       /*
-        * Ignore uinteresting and pruned commits
-        */
-       if (commit->object.flags & (UNINTERESTING | TREESAME))
-               return;
-
        /*
         * If the commit is already in the new_columns list, we don't need to
         * add it.  Just update the mapping correctly.
@@ -207,13 +339,48 @@ static void graph_insert_into_new_columns(struct git_graph *graph,
        graph->num_new_columns++;
 }
 
+static void graph_update_width(struct git_graph *graph,
+                              int is_commit_in_existing_columns)
+{
+       /*
+        * Compute the width needed to display the graph for this commit.
+        * This is the maximum width needed for any row.  All other rows
+        * will be padded to this width.
+        *
+        * Compute the number of columns in the widest row:
+        * Count each existing column (graph->num_columns), and each new
+        * column added by this commit.
+        */
+       int max_cols = graph->num_columns + graph->num_parents;
+
+       /*
+        * Even if the current commit has no parents to be printed, it
+        * still takes up a column for itself.
+        */
+       if (graph->num_parents < 1)
+               max_cols++;
+
+       /*
+        * We added a column for the the current commit as part of
+        * graph->num_parents.  If the current commit was already in
+        * graph->columns, then we have double counted it.
+        */
+       if (is_commit_in_existing_columns)
+               max_cols--;
+
+       /*
+        * Each column takes up 2 spaces
+        */
+       graph->width = max_cols * 2;
+}
+
 static void graph_update_columns(struct git_graph *graph)
 {
        struct commit_list *parent;
        struct column *tmp_columns;
        int max_new_columns;
        int mapping_idx;
-       int i, seen_this;
+       int i, seen_this, is_commit_in_columns;
 
        /*
         * Swap graph->columns with graph->new_columns
@@ -259,25 +426,37 @@ static void graph_update_columns(struct git_graph *graph)
         */
        seen_this = 0;
        mapping_idx = 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) {
+                       int old_mapping_idx = mapping_idx;
                        seen_this = 1;
-                       for (parent = graph->commit->parents;
+                       graph->commit_index = i;
+                       for (parent = first_interesting_parent(graph);
                             parent;
-                            parent = parent->next) {
+                            parent = next_interesting_parent(graph, parent)) {
                                graph_insert_into_new_columns(graph,
                                                              parent->item,
                                                              &mapping_idx);
                        }
+                       /*
+                        * We always need to increment mapping_idx by at
+                        * least 2, even if it has no interesting parents.
+                        * The current commit always takes up at least 2
+                        * spaces.
+                        */
+                       if (mapping_idx == old_mapping_idx)
+                               mapping_idx += 2;
                } else {
                        graph_insert_into_new_columns(graph, col_commit,
                                                      &mapping_idx);
@@ -290,6 +469,11 @@ static void graph_update_columns(struct git_graph *graph)
        while (graph->mapping_size > 1 &&
               graph->mapping[graph->mapping_size - 1] < 0)
                graph->mapping_size--;
+
+       /*
+        * Compute graph->width for this commit
+        */
+       graph_update_width(graph, is_commit_in_columns);
 }
 
 void graph_update(struct git_graph *graph, struct commit *commit)
@@ -302,11 +486,22 @@ void graph_update(struct git_graph *graph, struct commit *commit)
        graph->commit = commit;
 
        /*
-        * Count how many parents this commit has
+        * Count how many interesting parents this commit has
         */
        graph->num_parents = 0;
-       for (parent = commit->parents; parent; parent = parent->next)
+       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
@@ -318,21 +513,26 @@ void graph_update(struct git_graph *graph, struct commit *commit)
 
        /*
         * 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.
         *
-        * Otherwise, if there are 3 or more parents, we need to print
-        * extra rows before the commit, to expand the branch lines around
-        * it and make room for it.
+        * 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->num_parents >= 3)
+       else if (graph->num_parents >= 3 &&
+                graph->commit_index < (graph->num_columns - 1))
                graph->state = GRAPH_PRE_COMMIT;
        else
                graph->state = GRAPH_COMMIT;
@@ -368,22 +568,12 @@ static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb)
         *
         * This way, fields printed to the right of the graph will remain
         * aligned for the entire commit.
-        *
-        * This computation results in 3 extra space to the right in most
-        * cases, but only 1 extra space if the commit doesn't have any
-        * children that have already been displayed in the graph (i.e.,
-        * if the current commit isn't in graph->columns).
         */
-       size_t extra;
-       size_t final_width = graph->num_columns + graph->num_parents;
-       if (graph->num_parents < 1)
-               final_width++;
-       final_width *= 2;
-
-       if (sb->len >= final_width)
+       int extra;
+       if (sb->len >= graph->width)
                return;
 
-       extra = final_width - sb->len;
+       extra = graph->width - sb->len;
        strbuf_addf(sb, "%*s", (int) extra, "");
 }
 
@@ -421,10 +611,11 @@ static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
        strbuf_addstr(sb, "...");
        graph_pad_horizontally(graph, sb);
 
-       if (graph->num_parents >= 3)
-               graph->state = GRAPH_PRE_COMMIT;
+       if (graph->num_parents >= 3 &&
+           graph->commit_index < (graph->num_columns - 1))
+               graph_update_state(graph, GRAPH_PRE_COMMIT);
        else
-               graph->state = GRAPH_COMMIT;
+               graph_update_state(graph, GRAPH_COMMIT);
 }
 
 static void graph_output_pre_commit_line(struct git_graph *graph,
@@ -459,7 +650,22 @@ static void graph_output_pre_commit_line(struct git_graph *graph,
                if (col->commit == graph->commit) {
                        seen_this = 1;
                        strbuf_addf(sb, "| %*s", graph->expansion_row, "");
-               } else if (seen_this) {
+               } 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)
+                               strbuf_addstr(sb, "\\ ");
+                       else
+                               strbuf_addstr(sb, "| ");
+               } else if (seen_this && (graph->expansion_row > 0)) {
                        strbuf_addstr(sb, "\\ ");
                } else {
                        strbuf_addstr(sb, "| ");
@@ -474,10 +680,41 @@ static void graph_output_pre_commit_line(struct git_graph *graph,
         */
        graph->expansion_row++;
        if (graph->expansion_row >= num_expansion_rows)
-               graph->state = GRAPH_COMMIT;
+               graph_update_state(graph, GRAPH_COMMIT);
+}
+
+static void graph_output_commit_char(struct git_graph *graph, struct strbuf *sb)
+{
+       /*
+        * 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);
+               strbuf_addch(sb, 'o');
+               return;
+       }
+
+       /*
+        * If revs->left_right is set, print '<' for commits that
+        * come from the left side, and '>' for commits from the right
+        * side.
+        */
+       if (graph->revs && graph->revs->left_right) {
+               if (graph->commit->object.flags & SYMMETRIC_LEFT)
+                       strbuf_addch(sb, '<');
+               else
+                       strbuf_addch(sb, '>');
+               return;
+       }
+
+       /*
+        * Print '*' in all other cases
+        */
+       strbuf_addch(sb, '*');
 }
 
-void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
+static void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
 {
        int seen_this = 0;
        int i, j;
@@ -502,15 +739,10 @@ void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
 
                if (col_commit == graph->commit) {
                        seen_this = 1;
-                       if (graph->num_parents > 1)
-                               strbuf_addch(sb, 'M');
-                       else
-                               strbuf_addch(sb, '*');
+                       graph_output_commit_char(graph, sb);
 
-                       if (graph->num_parents < 2)
+                       if (graph->num_parents < 3)
                                strbuf_addch(sb, ' ');
-                       else if (graph->num_parents == 2)
-                               strbuf_addstr(sb, "  ");
                        else {
                                int num_dashes =
                                        ((graph->num_parents - 2) * 2) - 1;
@@ -518,8 +750,27 @@ void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
                                        strbuf_addch(sb, '-');
                                strbuf_addstr(sb, ". ");
                        }
-               } else if (seen_this && (graph->num_parents > 1)) {
+               } else if (seen_this && (graph->num_parents > 2)) {
                        strbuf_addstr(sb, "\\ ");
+               } else if (seen_this && (graph->num_parents == 2)) {
+                       /*
+                        * This is a 2-way merge commit.
+                        * There is no GRAPH_PRE_COMMIT stage for 2-way
+                        * 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_commit_index < i)
+                               strbuf_addstr(sb, "\\ ");
+                       else
+                               strbuf_addstr(sb, "| ");
                } else {
                        strbuf_addstr(sb, "| ");
                }
@@ -531,14 +782,14 @@ void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
         * Update graph->state
         */
        if (graph->num_parents > 1)
-               graph->state = GRAPH_POST_MERGE;
+               graph_update_state(graph, GRAPH_POST_MERGE);
        else if (graph_is_mapping_correct(graph))
-               graph->state = GRAPH_PADDING;
+               graph_update_state(graph, GRAPH_PADDING);
        else
-               graph->state = GRAPH_COLLAPSING;
+               graph_update_state(graph, GRAPH_COLLAPSING);
 }
 
-void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
+static void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
 {
        int seen_this = 0;
        int i, j;
@@ -561,9 +812,7 @@ void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
                        strbuf_addch(sb, '|');
                        for (j = 0; j < graph->num_parents - 1; j++)
                                strbuf_addstr(sb, "\\ ");
-                       if (graph->num_parents == 2)
-                               strbuf_addch(sb, ' ');
-               } else if (seen_this && (graph->num_parents > 2)) {
+               } else if (seen_this) {
                        strbuf_addstr(sb, "\\ ");
                } else {
                        strbuf_addstr(sb, "| ");
@@ -576,12 +825,12 @@ void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
         * Update graph->state
         */
        if (graph_is_mapping_correct(graph))
-               graph->state = GRAPH_PADDING;
+               graph_update_state(graph, GRAPH_PADDING);
        else
-               graph->state = GRAPH_COLLAPSING;
+               graph_update_state(graph, GRAPH_COLLAPSING);
 }
 
-void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb)
+static void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb)
 {
        int i;
        int *tmp_mapping;
@@ -683,10 +932,10 @@ void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb)
         * Otherwise, we need to collapse some branch lines together.
         */
        if (graph_is_mapping_correct(graph))
-               graph->state = GRAPH_PADDING;
+               graph_update_state(graph, GRAPH_PADDING);
 }
 
-int graph_next_line(struct git_graph *graph, struct strbuf *sb)
+static int graph_next_line(struct git_graph *graph, struct strbuf *sb)
 {
        switch (graph->state) {
        case GRAPH_PADDING:
@@ -713,7 +962,7 @@ int graph_next_line(struct git_graph *graph, struct strbuf *sb)
        return 0;
 }
 
-void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
+static void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
 {
        int i, j;
 
@@ -747,6 +996,11 @@ void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
        }
 
        graph_pad_horizontally(graph, sb);
+
+       /*
+        * 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)
@@ -830,7 +1084,7 @@ int graph_show_remainder(struct git_graph *graph)
 }
 
 
-void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb)
+static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb)
 {
        char *p;