git-rev-list libification: rev-list walking

This actually moves the "meat" of the revision walking from rev-list.c
to the new library code in revision.h. It introduces the new functions

	void prepare_revision_walk(struct rev_info *revs);
	struct commit *get_revision(struct rev_info *revs);

to prepare and then walk the revisions that we have.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/rev-list.c b/rev-list.c
index 2e80930b2cec2e20be00b5d7751af6a6626efdc2..94f22dd6733c096c46a2f8ab7f423972fa8bbba5 100644 (file)
--- a/rev-list.c
+++ b/rev-list.c
@@ -8,11 +8,10 @@
 #include "diff.h"
 #include "revision.h"
 
-/* bits #0 and #1 in revision.h */
+/* bits #0-2 in revision.h */
 
-#define COUNTED                (1u << 2)
-#define SHOWN          (1u << 3)
-#define TREECHANGE     (1u << 4)
+#define COUNTED                (1u << 3)
+#define SHOWN          (1u << 4)
 #define TMP_MARK       (1u << 5) /* for isolated cases; clean after use */
 
 static const char rev_list_usage[] =
@@ -213,17 +212,17 @@ static struct object_list **process_tree(struct tree *tree,
        return p;
 }
 
-static void show_commit_list(struct commit_list *list)
+static void show_commit_list(struct rev_info *revs)
 {
+       struct commit *commit;
        struct object_list *objects = NULL, **p = &objects, *pending;
-       while (list) {
-               struct commit *commit = pop_most_recent_commit(&list, SEEN);
 
+       while ((commit = get_revision(revs)) != NULL) {
                p = process_tree(commit->tree, p, NULL, "");
                if (process_commit(commit) == STOP)
                        break;
        }
-       for (pending = revs.pending_objects; pending; pending = pending->next) {
+       for (pending = revs->pending_objects; pending; pending = pending->next) {
                struct object *obj = pending->item;
                const char *name = pending->name;
                if (obj->flags & (UNINTERESTING | SEEN))
@@ -259,19 +258,6 @@ static void show_commit_list(struct commit_list *list)
        }
 }
 
-static int everybody_uninteresting(struct commit_list *orig)
-{
-       struct commit_list *list = orig;
-       while (list) {
-               struct commit *commit = list->item;
-               list = list->next;
-               if (commit->object.flags & UNINTERESTING)
-                       continue;
-               return 0;
-       }
-       return 1;
-}
-
 /*
  * This is a truly stupid algorithm, but it's only
  * used for bisection, and we just don't care enough.
@@ -379,224 +365,12 @@ static void mark_edges_uninteresting(struct commit_list *list)
        }
 }
 
-#define TREE_SAME      0
-#define TREE_NEW       1
-#define TREE_DIFFERENT 2
-static int tree_difference = 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;
-
-       /*
-        * 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).
-        */
-       if (addremove == '+') {
-               diff = tree_difference;
-               if (diff != TREE_SAME)
-                       return;
-               diff = TREE_NEW;
-       }
-       tree_difference = diff;
-}
-
-static void file_change(struct diff_options *options,
-                unsigned old_mode, unsigned new_mode,
-                const unsigned char *old_sha1,
-                const unsigned char *new_sha1,
-                const char *base, const char *path)
-{
-       tree_difference = TREE_DIFFERENT;
-}
-
-static struct diff_options diff_opt = {
-       .recursive = 1,
-       .add_remove = file_add_remove,
-       .change = file_change,
-};
-
-static int compare_tree(struct tree *t1, struct tree *t2)
-{
-       if (!t1)
-               return TREE_NEW;
-       if (!t2)
-               return TREE_DIFFERENT;
-       tree_difference = TREE_SAME;
-       if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
-               return TREE_DIFFERENT;
-       return tree_difference;
-}
-
-static int same_tree_as_empty(struct tree *t1)
-{
-       int retval;
-       void *tree;
-       struct tree_desc empty, real;
-
-       if (!t1)
-               return 0;
-
-       tree = read_object_with_reference(t1->object.sha1, "tree", &real.size, NULL);
-       if (!tree)
-               return 0;
-       real.buf = tree;
-
-       empty.buf = "";
-       empty.size = 0;
-
-       tree_difference = 0;
-       retval = diff_tree(&empty, &real, "", &diff_opt);
-       free(tree);
-
-       return retval >= 0 && !tree_difference;
-}
-
-static void try_to_simplify_commit(struct commit *commit)
-{
-       struct commit_list **pp, *parent;
-
-       if (!commit->tree)
-               return;
-
-       if (!commit->parents) {
-               if (!same_tree_as_empty(commit->tree))
-                       commit->object.flags |= TREECHANGE;
-               return;
-       }
-
-       pp = &commit->parents;
-       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:
-                       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;
-                       }
-               /* fallthrough */
-               case TREE_DIFFERENT:
-                       pp = &parent->next;
-                       continue;
-               }
-               die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
-       }
-       commit->object.flags |= TREECHANGE;
-}
-
-static void add_parents_to_list(struct commit *commit, struct commit_list **list)
-{
-       struct commit_list *parent = commit->parents;
-
-       /*
-        * If the commit is uninteresting, don't try to
-        * prune parents - we want the maximal uninteresting
-        * set.
-        *
-        * 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->object.flags & UNINTERESTING) {
-               while (parent) {
-                       struct commit *p = parent->item;
-                       parent = parent->next;
-                       parse_commit(p);
-                       p->object.flags |= UNINTERESTING;
-                       if (p->parents)
-                               mark_parents_uninteresting(p);
-                       if (p->object.flags & SEEN)
-                               continue;
-                       p->object.flags |= SEEN;
-                       insert_by_date(p, list);
-               }
-               return;
-       }
-
-       /*
-        * Ok, the commit wasn't uninteresting. Try to
-        * 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(commit);
-
-       parent = commit->parents;
-       while (parent) {
-               struct commit *p = parent->item;
-
-               parent = parent->next;
-
-               parse_commit(p);
-               if (p->object.flags & SEEN)
-                       continue;
-               p->object.flags |= SEEN;
-               insert_by_date(p, list);
-       }
-}
-
-static struct commit_list *limit_list(struct commit_list *list)
-{
-       struct commit_list *newlist = NULL;
-       struct commit_list **p = &newlist;
-       while (list) {
-               struct commit_list *entry = list;
-               struct commit *commit = list->item;
-               struct object *obj = &commit->object;
-
-               list = list->next;
-               free(entry);
-
-               if (revs.max_age != -1 && (commit->date < revs.max_age))
-                       obj->flags |= UNINTERESTING;
-               if (revs.unpacked && has_sha1_pack(obj->sha1))
-                       obj->flags |= UNINTERESTING;
-               add_parents_to_list(commit, &list);
-               if (obj->flags & UNINTERESTING) {
-                       mark_parents_uninteresting(commit);
-                       if (everybody_uninteresting(list))
-                               break;
-                       continue;
-               }
-               if (revs.min_age != -1 && (commit->date > revs.min_age))
-                       continue;
-               p = &commit_list_insert(commit, p)->next;
-       }
-       if (revs.tree_objects)
-               mark_edges_uninteresting(newlist);
-       if (bisect_list)
-               newlist = find_bisection(newlist);
-       return newlist;
-}
-
 int main(int argc, const char **argv)
 {
        struct commit_list *list;
        int i;
 
-       argc = setup_revisions(argc, argv, &revs);
+       argc = setup_revisions(argc, argv, &revs, NULL);
 
        for (i = 1 ; i < argc; i++) {
                const char *arg = argv[i];
@@ -672,24 +446,18 @@ int main(int argc, const char **argv)
            (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) && !revs.pending_objects))
                usage(rev_list_usage);
 
-       if (revs.paths)
-               diff_tree_setup_paths(revs.paths);
+       prepare_revision_walk(&revs);
+       if (revs.tree_objects)
+               mark_edges_uninteresting(revs.commits);
+
+       if (bisect_list)
+               revs.commits = find_bisection(revs.commits);
 
        save_commit_buffer = verbose_header;
        track_object_refs = 0;
 
-       if (!merge_order) {             
-               sort_by_date(&list);
-               if (list && !revs.limited && revs.max_count == 1 &&
-                   !revs.tag_objects && !revs.tree_objects && !revs.blob_objects) {
-                       show_commit(list->item);
-                       return 0;
-               }
-               if (revs.limited)
-                       list = limit_list(list);
-               if (revs.topo_order)
-                       sort_in_topological_order(&list, revs.lifo);
-               show_commit_list(list);
+       if (!merge_order) {
+               show_commit_list(&revs);
        } else {
 #ifndef NO_OPENSSL
                if (sort_list_in_merge_order(list, &process_commit)) {

diff --git a/revision.c b/revision.c
index 67ff4de2d1e70e061aebc834e7b9632c8d7bf6cb..f1ac62d7d85453b0d4b9b3969a432b1a488c4c60 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -3,6 +3,7 @@
 #include "blob.h"
 #include "tree.h"
 #include "commit.h"
+#include "diff.h"
 #include "refs.h"
 #include "revision.h"
 
@@ -183,6 +184,229 @@ static struct commit *get_commit_reference(struct rev_info *revs, const char *na
        die("%s is unknown object", name);
 }
 
+static int everybody_uninteresting(struct commit_list *orig)
+{
+       struct commit_list *list = orig;
+       while (list) {
+               struct commit *commit = list->item;
+               list = list->next;
+               if (commit->object.flags & UNINTERESTING)
+                       continue;
+               return 0;
+       }
+       return 1;
+}
+
+#define TREE_SAME      0
+#define TREE_NEW       1
+#define TREE_DIFFERENT 2
+static int tree_difference = 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;
+
+       /*
+        * 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).
+        */
+       if (addremove == '+') {
+               diff = tree_difference;
+               if (diff != TREE_SAME)
+                       return;
+               diff = TREE_NEW;
+       }
+       tree_difference = diff;
+}
+
+static void file_change(struct diff_options *options,
+                unsigned old_mode, unsigned new_mode,
+                const unsigned char *old_sha1,
+                const unsigned char *new_sha1,
+                const char *base, const char *path)
+{
+       tree_difference = TREE_DIFFERENT;
+}
+
+static struct diff_options diff_opt = {
+       .recursive = 1,
+       .add_remove = file_add_remove,
+       .change = file_change,
+};
+
+static int compare_tree(struct tree *t1, struct tree *t2)
+{
+       if (!t1)
+               return TREE_NEW;
+       if (!t2)
+               return TREE_DIFFERENT;
+       tree_difference = TREE_SAME;
+       if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "", &diff_opt) < 0)
+               return TREE_DIFFERENT;
+       return tree_difference;
+}
+
+static int same_tree_as_empty(struct tree *t1)
+{
+       int retval;
+       void *tree;
+       struct tree_desc empty, real;
+
+       if (!t1)
+               return 0;
+
+       tree = read_object_with_reference(t1->object.sha1, "tree", &real.size, NULL);
+       if (!tree)
+               return 0;
+       real.buf = tree;
+
+       empty.buf = "";
+       empty.size = 0;
+
+       tree_difference = 0;
+       retval = diff_tree(&empty, &real, "", &diff_opt);
+       free(tree);
+
+       return retval >= 0 && !tree_difference;
+}
+
+static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
+{
+       struct commit_list **pp, *parent;
+
+       if (!commit->tree)
+               return;
+
+       if (!commit->parents) {
+               if (!same_tree_as_empty(commit->tree))
+                       commit->object.flags |= TREECHANGE;
+               return;
+       }
+
+       pp = &commit->parents;
+       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:
+                       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;
+                       }
+               /* fallthrough */
+               case TREE_DIFFERENT:
+                       pp = &parent->next;
+                       continue;
+               }
+               die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
+       }
+       commit->object.flags |= TREECHANGE;
+}
+
+static void add_parents_to_list(struct rev_info *revs, struct commit *commit, struct commit_list **list)
+{
+       struct commit_list *parent = commit->parents;
+
+       /*
+        * If the commit is uninteresting, don't try to
+        * prune parents - we want the maximal uninteresting
+        * set.
+        *
+        * 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->object.flags & UNINTERESTING) {
+               while (parent) {
+                       struct commit *p = parent->item;
+                       parent = parent->next;
+                       parse_commit(p);
+                       p->object.flags |= UNINTERESTING;
+                       if (p->parents)
+                               mark_parents_uninteresting(p);
+                       if (p->object.flags & SEEN)
+                               continue;
+                       p->object.flags |= SEEN;
+                       insert_by_date(p, list);
+               }
+               return;
+       }
+
+       /*
+        * Ok, the commit wasn't uninteresting. Try to
+        * 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);
+
+       parent = commit->parents;
+       while (parent) {
+               struct commit *p = parent->item;
+
+               parent = parent->next;
+
+               parse_commit(p);
+               if (p->object.flags & SEEN)
+                       continue;
+               p->object.flags |= SEEN;
+               insert_by_date(p, list);
+       }
+}
+
+static void limit_list(struct rev_info *revs)
+{
+       struct commit_list *list = revs->commits;
+       struct commit_list *newlist = NULL;
+       struct commit_list **p = &newlist;
+
+       while (list) {
+               struct commit_list *entry = list;
+               struct commit *commit = list->item;
+               struct object *obj = &commit->object;
+
+               list = list->next;
+               free(entry);
+
+               if (revs->max_age != -1 && (commit->date < revs->max_age))
+                       obj->flags |= UNINTERESTING;
+               if (revs->unpacked && has_sha1_pack(obj->sha1))
+                       obj->flags |= UNINTERESTING;
+               add_parents_to_list(revs, commit, &list);
+               if (obj->flags & UNINTERESTING) {
+                       mark_parents_uninteresting(commit);
+                       if (everybody_uninteresting(list))
+                               break;
+                       continue;
+               }
+               if (revs->min_age != -1 && (commit->date > revs->min_age))
+                       continue;
+               p = &commit_list_insert(commit, p)->next;
+       }
+       revs->commits = newlist;
+}
+
 static void add_one_commit(struct commit *commit, struct rev_info *revs)
 {
        if (!commit || (commit->object.flags & SEEN))
@@ -214,10 +438,9 @@ static void handle_all(struct rev_info *revs, unsigned flags)
  *
  * Returns the number of arguments left ("new argc").
  */
-int setup_revisions(int argc, const char **argv, struct rev_info *revs)
+int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 {
        int i, flags, seen_dashdash;
-       const char *def = NULL;
        const char **unrecognized = argv+1;
        int left = 1;
 
@@ -381,3 +604,23 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs)
        *unrecognized = NULL;
        return left;
 }
+
+void prepare_revision_walk(struct rev_info *revs)
+{
+       if (revs->paths)
+               diff_tree_setup_paths(revs->paths);
+       sort_by_date(&revs->commits);
+       if (revs->limited)
+               limit_list(revs);
+       if (revs->topo_order)
+               sort_in_topological_order(&revs->commits, revs->lifo);
+}
+
+struct commit *get_revision(struct rev_info *revs)
+{
+       if (!revs->commits)
+               return NULL;
+       return pop_most_recent_commit(&revs->commits, SEEN);
+}
+
+

diff --git a/revision.h b/revision.h
index a22f198515f9cce097bad41cb64139eff7459540..0bed3c04ff777276f04f4f13b10764653923430f 100644 (file)
--- a/revision.h
+++ b/revision.h
@@ -3,6 +3,7 @@
 
 #define SEEN           (1u<<0)
 #define UNINTERESTING   (1u<<1)
+#define TREECHANGE     (1u<<2)
 
 struct rev_info {
        /* Starting list */
@@ -32,7 +33,10 @@ struct rev_info {
 };
 
 /* revision.c */
-extern int setup_revisions(int argc, const char **argv, struct rev_info *revs);
+extern int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def);
+extern void prepare_revision_walk(struct rev_info *revs);
+extern struct commit *get_revision(struct rev_info *revs);
+
 extern void mark_parents_uninteresting(struct commit *commit);
 extern void mark_tree_uninteresting(struct tree *tree);