Replace xmalloc/memset(0) pairs with xcalloc
[gitweb.git] / commit.c
index 94d5b3d2618d335585084170ef6a3a8e67f34c62..c99db162a48e0a47e73e6bfc2ae5fd4b7c9dfa1a 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -160,7 +160,7 @@ struct commit_graft *read_graft_line(char *buf, int len)
        return graft;
 }
 
-int read_graft_file(const char *graft_file)
+static int read_graft_file(const char *graft_file)
 {
        FILE *fp = fopen(graft_file, "r");
        char buf[1024];
@@ -243,7 +243,6 @@ int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
        unsigned char parent[20];
        struct commit_list **pptr;
        struct commit_graft *graft;
-       unsigned n_refs = 0;
 
        if (item->object.parsed)
                return 0;
@@ -255,8 +254,6 @@ int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
                return error("bad tree pointer in commit %s",
                             sha1_to_hex(item->object.sha1));
        item->tree = lookup_tree(parent);
-       if (item->tree)
-               n_refs++;
        bufptr += 46; /* "tree " + "hex sha1" + "\n" */
        pptr = &item->parents;
 
@@ -272,10 +269,8 @@ int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
                if (graft)
                        continue;
                new_parent = lookup_commit(parent);
-               if (new_parent) {
+               if (new_parent)
                        pptr = &commit_list_insert(new_parent, pptr)->next;
-                       n_refs++;
-               }
        }
        if (graft) {
                int i;
@@ -285,7 +280,6 @@ int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size)
                        if (!new_parent)
                                continue;
                        pptr = &commit_list_insert(new_parent, pptr)->next;
-                       n_refs++;
                }
        }
        item->date = parse_commit_date(bufptr, tail);
@@ -331,6 +325,14 @@ struct commit_list *commit_list_insert(struct commit *item, struct commit_list *
        return new_list;
 }
 
+unsigned commit_list_count(const struct commit_list *l)
+{
+       unsigned c = 0;
+       for (; l; l = l->next )
+               c++;
+       return c;
+}
+
 void free_commit_list(struct commit_list *list)
 {
        while (list) {
@@ -434,8 +436,7 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
        /* Mark them and clear the indegree */
        for (next = orig; next; next = next->next) {
                struct commit *commit = next->item;
-               commit->object.flags |= TOPOSORT;
-               commit->indegree = 0;
+               commit->indegree = 1;
        }
 
        /* update the indegree */
@@ -444,7 +445,7 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
                while (parents) {
                        struct commit *parent = parents->item;
 
-                       if (parent->object.flags & TOPOSORT)
+                       if (parent->indegree)
                                parent->indegree++;
                        parents = parents->next;
                }
@@ -462,7 +463,7 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
        for (next = orig; next; next = next->next) {
                struct commit *commit = next->item;
 
-               if (!commit->indegree)
+               if (commit->indegree == 1)
                        insert = &commit_list_insert(commit, insert)->next;
        }
 
@@ -484,7 +485,7 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
                for (parents = commit->parents; parents ; parents = parents->next) {
                        struct commit *parent=parents->item;
 
-                       if (!(parent->object.flags & TOPOSORT))
+                       if (!parent->indegree)
                                continue;
 
                        /*
@@ -492,7 +493,7 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
                         * when all their children have been emitted thereby
                         * guaranteeing topological order.
                         */
-                       if (!--parent->indegree) {
+                       if (--parent->indegree == 1) {
                                if (!lifo)
                                        insert_by_date(parent, &work);
                                else
@@ -503,7 +504,7 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
                 * work_item is a commit all of whose children
                 * have already been emitted. we can emit it now.
                 */
-               commit->object.flags &= ~TOPOSORT;
+               commit->indegree = 0;
                *pptr = work_item;
                pptr = &work_item->next;
        }
@@ -531,26 +532,34 @@ static struct commit *interesting(struct commit_list *list)
        return NULL;
 }
 
-static struct commit_list *merge_bases(struct commit *one, struct commit *two)
+static struct commit_list *merge_bases_many(struct commit *one, int n, struct commit **twos)
 {
        struct commit_list *list = NULL;
        struct commit_list *result = NULL;
+       int i;
 
-       if (one == two)
-               /* We do not mark this even with RESULT so we do not
-                * have to clean it up.
-                */
-               return commit_list_insert(one, &result);
+       for (i = 0; i < n; i++) {
+               if (one == twos[i])
+                       /*
+                        * We do not mark this even with RESULT so we do not
+                        * have to clean it up.
+                        */
+                       return commit_list_insert(one, &result);
+       }
 
        if (parse_commit(one))
                return NULL;
-       if (parse_commit(two))
-               return NULL;
+       for (i = 0; i < n; i++) {
+               if (parse_commit(twos[i]))
+                       return NULL;
+       }
 
        one->object.flags |= PARENT1;
-       two->object.flags |= PARENT2;
        insert_by_date(one, &list);
-       insert_by_date(two, &list);
+       for (i = 0; i < n; i++) {
+               twos[i]->object.flags |= PARENT2;
+               insert_by_date(twos[i], &list);
+       }
 
        while (interesting(list)) {
                struct commit *commit;
@@ -598,21 +607,53 @@ static struct commit_list *merge_bases(struct commit *one, struct commit *two)
        return result;
 }
 
-struct commit_list *get_merge_bases(struct commit *one,
-                                       struct commit *two, int cleanup)
+struct commit_list *get_octopus_merge_bases(struct commit_list *in)
+{
+       struct commit_list *i, *j, *k, *ret = NULL;
+       struct commit_list **pptr = &ret;
+
+       for (i = in; i; i = i->next) {
+               if (!ret)
+                       pptr = &commit_list_insert(i->item, pptr)->next;
+               else {
+                       struct commit_list *new = NULL, *end = NULL;
+
+                       for (j = ret; j; j = j->next) {
+                               struct commit_list *bases;
+                               bases = get_merge_bases(i->item, j->item, 1);
+                               if (!new)
+                                       new = bases;
+                               else
+                                       end->next = bases;
+                               for (k = bases; k; k = k->next)
+                                       end = k;
+                       }
+                       ret = new;
+               }
+       }
+       return ret;
+}
+
+struct commit_list *get_merge_bases_many(struct commit *one,
+                                        int n,
+                                        struct commit **twos,
+                                        int cleanup)
 {
        struct commit_list *list;
        struct commit **rslt;
        struct commit_list *result;
        int cnt, i, j;
 
-       result = merge_bases(one, two);
-       if (one == two)
-               return result;
+       result = merge_bases_many(one, n, twos);
+       for (i = 0; i < n; i++) {
+               if (one == twos[i])
+                       return result;
+       }
        if (!result || !result->next) {
                if (cleanup) {
                        clear_commit_marks(one, all_flags);
-                       clear_commit_marks(two, all_flags);
+                       for (i = 0; i < n; i++)
+                               clear_commit_marks(twos[i], all_flags);
                }
                return result;
        }
@@ -630,12 +671,13 @@ struct commit_list *get_merge_bases(struct commit *one,
        free_commit_list(result);
 
        clear_commit_marks(one, all_flags);
-       clear_commit_marks(two, all_flags);
+       for (i = 0; i < n; i++)
+               clear_commit_marks(twos[i], all_flags);
        for (i = 0; i < cnt - 1; i++) {
                for (j = i+1; j < cnt; j++) {
                        if (!rslt[i] || !rslt[j])
                                continue;
-                       result = merge_bases(rslt[i], rslt[j]);
+                       result = merge_bases_many(rslt[i], 1, &rslt[j]);
                        clear_commit_marks(rslt[i], all_flags);
                        clear_commit_marks(rslt[j], all_flags);
                        for (list = result; list; list = list->next) {
@@ -657,6 +699,12 @@ struct commit_list *get_merge_bases(struct commit *one,
        return result;
 }
 
+struct commit_list *get_merge_bases(struct commit *one, struct commit *two,
+                                   int cleanup)
+{
+       return get_merge_bases_many(one, 1, &two, cleanup);
+}
+
 int in_merge_bases(struct commit *commit, struct commit **reference, int num)
 {
        struct commit_list *bases, *b;
@@ -676,3 +724,55 @@ int in_merge_bases(struct commit *commit, struct commit **reference, int num)
        free_commit_list(bases);
        return ret;
 }
+
+struct commit_list *reduce_heads(struct commit_list *heads)
+{
+       struct commit_list *p;
+       struct commit_list *result = NULL, **tail = &result;
+       struct commit **other;
+       size_t num_head, num_other;
+
+       if (!heads)
+               return NULL;
+
+       /* Avoid unnecessary reallocations */
+       for (p = heads, num_head = 0; p; p = p->next)
+               num_head++;
+       other = xcalloc(sizeof(*other), num_head);
+
+       /* For each commit, see if it can be reached by others */
+       for (p = heads; p; p = p->next) {
+               struct commit_list *q, *base;
+
+               /* Do we already have this in the result? */
+               for (q = result; q; q = q->next)
+                       if (p->item == q->item)
+                               break;
+               if (q)
+                       continue;
+
+               num_other = 0;
+               for (q = heads; q; q = q->next) {
+                       if (p->item == q->item)
+                               continue;
+                       other[num_other++] = q->item;
+               }
+               if (num_other)
+                       base = get_merge_bases_many(p->item, num_other, other, 1);
+               else
+                       base = NULL;
+               /*
+                * If p->item does not have anything common with other
+                * commits, there won't be any merge base.  If it is
+                * reachable from some of the others, p->item will be
+                * the merge base.  If its history is connected with
+                * others, but p->item is not reachable by others, we
+                * will get something other than p->item back.
+                */
+               if (!base || (base->item != p->item))
+                       tail = &(commit_list_insert(p->item, tail)->next);
+               free_commit_list(base);
+       }
+       free(other);
+       return result;
+}