Use a *real* built-in diff generator
[gitweb.git] / revision.c
index 48858714250da8e7328c132f60dfcd076d103433..12cd0529a5dfac9af01af0f47e895e9cf142c42a 100644 (file)
@@ -82,18 +82,20 @@ void mark_parents_uninteresting(struct commit *commit)
 
        while (parents) {
                struct commit *commit = parents->item;
-               commit->object.flags |= UNINTERESTING;
-
-               /*
-                * Normally we haven't parsed the parent
-                * yet, so we won't have a parent of a parent
-                * here. However, it may turn out that we've
-                * reached this commit some other way (where it
-                * wasn't uninteresting), in which case we need
-                * to mark its parents recursively too..
-                */
-               if (commit->parents)
-                       mark_parents_uninteresting(commit);
+               if (!(commit->object.flags & UNINTERESTING)) {
+                       commit->object.flags |= UNINTERESTING;
+
+                       /*
+                        * Normally we haven't parsed the parent
+                        * yet, so we won't have a parent of a parent
+                        * here. However, it may turn out that we've
+                        * reached this commit some other way (where it
+                        * wasn't uninteresting), in which case we need
+                        * to mark its parents recursively too..
+                        */
+                       if (commit->parents)
+                               mark_parents_uninteresting(commit);
+               }
 
                /*
                 * A missing commit is ok iff its parent is marked
@@ -197,31 +199,27 @@ static int everybody_uninteresting(struct commit_list *orig)
        return 1;
 }
 
-#define TREE_SAME      0
-#define TREE_NEW       1
-#define TREE_DIFFERENT 2
-static int tree_difference = TREE_SAME;
+static int tree_difference = REV_TREE_SAME;
 
 static void file_add_remove(struct diff_options *options,
                    int addremove, unsigned mode,
                    const unsigned char *sha1,
                    const char *base, const char *path)
 {
-       int diff = TREE_DIFFERENT;
+       int diff = REV_TREE_DIFFERENT;
 
        /*
-        * Is it an add of a new file? It means that
-        * the old tree didn't have it at all, so we
-        * will turn "TREE_SAME" -> "TREE_NEW", but
-        * leave any "TREE_DIFFERENT" alone (and if
-        * it already was "TREE_NEW", we'll keep it
-        * "TREE_NEW" of course).
+        * Is it an add of a new file? It means that the old tree
+        * didn't have it at all, so we will turn "REV_TREE_SAME" ->
+        * "REV_TREE_NEW", but leave any "REV_TREE_DIFFERENT" alone
+        * (and if it already was "REV_TREE_NEW", we'll keep it
+        * "REV_TREE_NEW" of course).
         */
        if (addremove == '+') {
                diff = tree_difference;
-               if (diff != TREE_SAME)
+               if (diff != REV_TREE_SAME)
                        return;
-               diff = TREE_NEW;
+               diff = REV_TREE_NEW;
        }
        tree_difference = diff;
 }
@@ -232,7 +230,7 @@ static void file_change(struct diff_options *options,
                 const unsigned char *new_sha1,
                 const char *base, const char *path)
 {
-       tree_difference = TREE_DIFFERENT;
+       tree_difference = REV_TREE_DIFFERENT;
 }
 
 static struct diff_options diff_opt = {
@@ -241,19 +239,19 @@ static struct diff_options diff_opt = {
        .change = file_change,
 };
 
-static int compare_tree(struct tree *t1, struct tree *t2)
+int rev_compare_tree(struct tree *t1, struct tree *t2)
 {
        if (!t1)
-               return TREE_NEW;
+               return REV_TREE_NEW;
        if (!t2)
-               return TREE_DIFFERENT;
-       tree_difference = TREE_SAME;
+               return REV_TREE_DIFFERENT;
+       tree_difference = REV_TREE_SAME;
        if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
-               return TREE_DIFFERENT;
+               return REV_TREE_DIFFERENT;
        return tree_difference;
 }
 
-static int same_tree_as_empty(struct tree *t1)
+int rev_same_tree_as_empty(struct tree *t1)
 {
        int retval;
        void *tree;
@@ -280,12 +278,13 @@ static int same_tree_as_empty(struct tree *t1)
 static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
 {
        struct commit_list **pp, *parent;
+       int tree_changed = 0;
 
        if (!commit->tree)
                return;
 
        if (!commit->parents) {
-               if (!same_tree_as_empty(commit->tree))
+               if (!rev_same_tree_as_empty(commit->tree))
                        commit->object.flags |= TREECHANGE;
                return;
        }
@@ -294,31 +293,47 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
        while ((parent = *pp) != NULL) {
                struct commit *p = parent->item;
 
-               if (p->object.flags & UNINTERESTING) {
-                       pp = &parent->next;
-                       continue;
-               }
-
                parse_commit(p);
-               switch (compare_tree(p->tree, commit->tree)) {
-               case TREE_SAME:
+               switch (rev_compare_tree(p->tree, commit->tree)) {
+               case REV_TREE_SAME:
+                       if (p->object.flags & UNINTERESTING) {
+                               /* Even if a merge with an uninteresting
+                                * side branch brought the entire change
+                                * we are interested in, we do not want
+                                * to lose the other branches of this
+                                * merge, so we just keep going.
+                                */
+                               pp = &parent->next;
+                               continue;
+                       }
                        parent->next = NULL;
                        commit->parents = parent;
                        return;
 
-               case TREE_NEW:
-                       if (revs->remove_empty_trees && same_tree_as_empty(p->tree)) {
-                               *pp = parent->next;
-                               continue;
+               case REV_TREE_NEW:
+                       if (revs->remove_empty_trees &&
+                           rev_same_tree_as_empty(p->tree)) {
+                               /* We are adding all the specified
+                                * paths from this parent, so the
+                                * history beyond this parent is not
+                                * interesting.  Remove its parents
+                                * (they are grandparents for us).
+                                * IOW, we pretend this parent is a
+                                * "root" commit.
+                                */
+                               parse_commit(p);
+                               p->parents = NULL;
                        }
                /* fallthrough */
-               case TREE_DIFFERENT:
+               case REV_TREE_DIFFERENT:
+                       tree_changed = 1;
                        pp = &parent->next;
                        continue;
                }
                die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
        }
-       commit->object.flags |= TREECHANGE;
+       if (tree_changed)
+               commit->object.flags |= TREECHANGE;
 }
 
 static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
@@ -358,8 +373,8 @@ static void add_parents_to_list(struct rev_info *revs, struct commit *commit, st
         * simplify the commit history and find the parent
         * that has no differences in the path set if one exists.
         */
-       if (revs->paths)
-               try_to_simplify_commit(revs, commit);
+       if (revs->prune_fn)
+               revs->prune_fn(revs, commit);
 
        parent = commit->parents;
        while (parent) {
@@ -381,9 +396,6 @@ static void limit_list(struct rev_info *revs)
        struct commit_list *newlist = NULL;
        struct commit_list **p = &newlist;
 
-       if (revs->paths)
-               diff_tree_setup_paths(revs->paths);
-
        while (list) {
                struct commit_list *entry = list;
                struct commit *commit = list->item;
@@ -435,6 +447,23 @@ static void handle_all(struct rev_info *revs, unsigned flags)
        for_each_ref(handle_one_ref);
 }
 
+void init_revisions(struct rev_info *revs)
+{
+       memset(revs, 0, sizeof(*revs));
+       revs->lifo = 1;
+       revs->dense = 1;
+       revs->prefix = setup_git_directory();
+       revs->max_age = -1;
+       revs->min_age = -1;
+       revs->max_count = -1;
+
+       revs->prune_fn = NULL;
+       revs->prune_data = NULL;
+
+       revs->topo_setter = topo_sort_default_setter;
+       revs->topo_getter = topo_sort_default_getter;
+}
+
 /*
  * Parse revision information, filling in the "rev_info" structure,
  * and removing the used arguments from the argument list.
@@ -448,13 +477,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
        const char **unrecognized = argv + 1;
        int left = 1;
 
-       memset(revs, 0, sizeof(*revs));
-       revs->lifo = 1;
-       revs->dense = 1;
-       revs->prefix = setup_git_directory();
-       revs->max_age = -1;
-       revs->min_age = -1;
-       revs->max_count = -1;
+       init_revisions(revs);
 
        /* First, search for "--" */
        seen_dashdash = 0;
@@ -464,7 +487,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                        continue;
                argv[i] = NULL;
                argc = i;
-               revs->paths = get_pathspec(revs->prefix, argv + i + 1);
+               revs->prune_data = get_pathspec(revs->prefix, argv + i + 1);
                seen_dashdash = 1;
                break;
        }
@@ -482,6 +505,21 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                revs->max_count = atoi(arg + 12);
                                continue;
                        }
+                       /* accept -<digit>, like traditilnal "head" */
+                       if ((*arg == '-') && isdigit(arg[1])) {
+                               revs->max_count = atoi(arg + 1);
+                               continue;
+                       }
+                       if (!strcmp(arg, "-n")) {
+                               if (argc <= i + 1)
+                                       die("-n requires an argument");
+                               revs->max_count = atoi(argv[++i]);
+                               continue;
+                       }
+                       if (!strncmp(arg,"-n",2)) {
+                               revs->max_count = atoi(arg + 2);
+                               continue;
+                       }
                        if (!strncmp(arg, "--max-age=", 10)) {
                                revs->max_age = atoi(arg + 10);
                                revs->limited = 1;
@@ -613,7 +651,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                                if (lstat(argv[j], &st) < 0)
                                        die("'%s': %s", arg, strerror(errno));
                        }
-                       revs->paths = get_pathspec(revs->prefix, argv + i);
+                       revs->prune_data = get_pathspec(revs->prefix, argv + i);
                        break;
                }
                commit = get_commit_reference(revs, arg, sha1, flags ^ local_flags);
@@ -627,8 +665,13 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
                commit = get_commit_reference(revs, def, sha1, 0);
                add_one_commit(commit, revs);
        }
-       if (revs->paths)
+
+       if (revs->prune_data) {
+               diff_tree_setup_paths(revs->prune_data);
+               revs->prune_fn = try_to_simplify_commit;
                revs->limited = 1;
+       }
+
        return left;
 }
 
@@ -638,7 +681,9 @@ void prepare_revision_walk(struct rev_info *revs)
        if (revs->limited)
                limit_list(revs);
        if (revs->topo_order)
-               sort_in_topological_order(&revs->commits, revs->lifo);
+               sort_in_topological_order_fn(&revs->commits, revs->lifo,
+                                            revs->topo_setter,
+                                            revs->topo_getter);
 }
 
 static int rewrite_one(struct commit **pp)
@@ -669,13 +714,11 @@ static void rewrite_parents(struct commit *commit)
 struct commit *get_revision(struct rev_info *revs)
 {
        struct commit_list *list = revs->commits;
-       struct commit *commit;
 
        if (!list)
                return NULL;
 
        /* Check the max_count ... */
-       commit = list->item;
        switch (revs->max_count) {
        case -1:
                break;
@@ -686,22 +729,28 @@ struct commit *get_revision(struct rev_info *revs)
        }
 
        do {
-               commit = pop_most_recent_commit(&revs->commits, SEEN);
+               struct commit *commit = revs->commits->item;
+
                if (commit->object.flags & (UNINTERESTING|SHOWN))
-                       continue;
+                       goto next;
                if (revs->min_age != -1 && (commit->date > revs->min_age))
-                       continue;
+                       goto next;
                if (revs->max_age != -1 && (commit->date < revs->max_age))
                        return NULL;
                if (revs->no_merges && commit->parents && commit->parents->next)
-                       continue;
-               if (revs->paths && revs->dense) {
+                       goto next;
+               if (revs->prune_fn && revs->dense) {
                        if (!(commit->object.flags & TREECHANGE))
-                               continue;
+                               goto next;
                        rewrite_parents(commit);
                }
+               /* More to go? */
+               if (revs->max_count)
+                       pop_most_recent_commit(&revs->commits, SEEN);
                commit->object.flags |= SHOWN;
                return commit;
+next:
+               pop_most_recent_commit(&revs->commits, SEEN);
        } while (revs->commits);
        return NULL;
 }