[PATCH] Avoid wasting memory in git-rev-list
[git/git.git] / rev-list.c
index 1c797d2..96aa342 100644 (file)
 #include "cache.h"
+#include "tag.h"
 #include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "epoch.h"
 
-int main(int argc, char **argv)
+#define SEEN           (1u << 0)
+#define INTERESTING    (1u << 1)
+#define COUNTED                (1u << 2)
+#define SHOWN          (1u << 3)
+
+static const char rev_list_usage[] =
+       "git-rev-list [OPTION] commit-id <commit-id>\n"
+                     "  --max-count=nr\n"
+                     "  --max-age=epoch\n"
+                     "  --min-age=epoch\n"
+                     "  --parents\n"
+                     "  --bisect\n"
+                     "  --objects\n"
+                     "  --unpacked\n"
+                     "  --header\n"
+                     "  --pretty\n"
+                     "  --no-merges\n"
+                     "  --merge-order [ --show-breaks ]\n"
+                     "  --topo-order";
+
+static int unpacked = 0;
+static int bisect_list = 0;
+static int tag_objects = 0;
+static int tree_objects = 0;
+static int blob_objects = 0;
+static int verbose_header = 0;
+static int show_parents = 0;
+static int hdr_termination = 0;
+static const char *commit_prefix = "";
+static unsigned long max_age = -1;
+static unsigned long min_age = -1;
+static int max_count = -1;
+static enum cmit_fmt commit_format = CMIT_FMT_RAW;
+static int merge_order = 0;
+static int show_breaks = 0;
+static int stop_traversal = 0;
+static int topo_order = 0;
+static int no_merges = 0;
+
+static void show_commit(struct commit *commit)
+{
+       commit->object.flags |= SHOWN;
+       if (show_breaks) {
+               commit_prefix = "| ";
+               if (commit->object.flags & DISCONTINUITY) {
+                       commit_prefix = "^ ";     
+               } else if (commit->object.flags & BOUNDARY) {
+                       commit_prefix = "= ";
+               } 
+        }                      
+       printf("%s%s", commit_prefix, sha1_to_hex(commit->object.sha1));
+       if (show_parents) {
+               struct commit_list *parents = commit->parents;
+               while (parents) {
+                       printf(" %s", sha1_to_hex(parents->item->object.sha1));
+                       parents = parents->next;
+               }
+       }
+       if (commit_format == CMIT_FMT_ONELINE)
+               putchar(' ');
+       else
+               putchar('\n');
+
+       if (verbose_header) {
+               static char pretty_header[16384];
+               pretty_print_commit(commit_format, commit->buffer, ~0, pretty_header, sizeof(pretty_header));
+               printf("%s%c", pretty_header, hdr_termination);
+       }
+       fflush(stdout);
+}
+
+static int filter_commit(struct commit * commit)
+{
+       if (stop_traversal && (commit->object.flags & BOUNDARY))
+               return STOP;
+       if (commit->object.flags & (UNINTERESTING|SHOWN))
+               return CONTINUE;
+       if (min_age != -1 && (commit->date > min_age))
+               return CONTINUE;
+       if (max_age != -1 && (commit->date < max_age)) {
+               stop_traversal=1;
+               return merge_order?CONTINUE:STOP;
+       }
+       if (max_count != -1 && !max_count--)
+               return STOP;
+       if (no_merges && (commit->parents && commit->parents->next))
+               return CONTINUE;
+       return DO;
+}
+
+static int process_commit(struct commit * commit)
+{
+       int action=filter_commit(commit);
+
+       if (action == STOP) {
+               return STOP;
+       }
+
+       if (action == CONTINUE) {
+               return CONTINUE;
+       }
+
+       show_commit(commit);
+
+       return CONTINUE;
+}
+
+static struct object_list **add_object(struct object *obj, struct object_list **p, const char *name)
+{
+       struct object_list *entry = xmalloc(sizeof(*entry));
+       entry->item = obj;
+       entry->next = *p;
+       entry->name = name;
+       *p = entry;
+       return &entry->next;
+}
+
+static struct object_list **process_blob(struct blob *blob, struct object_list **p, const char *name)
+{
+       struct object *obj = &blob->object;
+
+       if (!blob_objects)
+               return p;
+       if (obj->flags & (UNINTERESTING | SEEN))
+               return p;
+       obj->flags |= SEEN;
+       return add_object(obj, p, name);
+}
+
+static struct object_list **process_tree(struct tree *tree, struct object_list **p, const char *name)
+{
+       struct object *obj = &tree->object;
+       struct tree_entry_list *entry;
+
+       if (!tree_objects)
+               return p;
+       if (obj->flags & (UNINTERESTING | SEEN))
+               return p;
+       if (parse_tree(tree) < 0)
+               die("bad tree object %s", sha1_to_hex(obj->sha1));
+       obj->flags |= SEEN;
+       p = add_object(obj, p, name);
+       for (entry = tree->entries ; entry ; entry = entry->next) {
+               if (entry->directory)
+                       p = process_tree(entry->item.tree, p, entry->name);
+               else
+                       p = process_blob(entry->item.blob, p, entry->name);
+       }
+       return p;
+}
+
+static struct object_list *pending_objects = NULL;
+
+static void show_commit_list(struct commit_list *list)
+{
+       struct object_list *objects = NULL, **p = &objects, *pending;
+       while (list) {
+               struct commit *commit = pop_most_recent_commit(&list, SEEN);
+
+               p = process_tree(commit->tree, p, "");
+               if (process_commit(commit) == STOP)
+                       break;
+       }
+       for (pending = pending_objects; pending; pending = pending->next) {
+               struct object *obj = pending->item;
+               const char *name = pending->name;
+               if (obj->flags & (UNINTERESTING | SEEN))
+                       continue;
+               if (obj->type == tag_type) {
+                       obj->flags |= SEEN;
+                       p = add_object(obj, p, name);
+                       continue;
+               }
+               if (obj->type == tree_type) {
+                       p = process_tree((struct tree *)obj, p, name);
+                       continue;
+               }
+               if (obj->type == blob_type) {
+                       p = process_blob((struct blob *)obj, p, name);
+                       continue;
+               }
+               die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
+       }
+       while (objects) {
+               printf("%s %s\n", sha1_to_hex(objects->item->sha1), objects->name);
+               objects = objects->next;
+       }
+}
+
+static void mark_blob_uninteresting(struct blob *blob)
+{
+       if (!blob_objects)
+               return;
+       if (blob->object.flags & UNINTERESTING)
+               return;
+       blob->object.flags |= UNINTERESTING;
+}
+
+static void mark_tree_uninteresting(struct tree *tree)
+{
+       struct object *obj = &tree->object;
+       struct tree_entry_list *entry;
+
+       if (!tree_objects)
+               return;
+       if (obj->flags & UNINTERESTING)
+               return;
+       obj->flags |= UNINTERESTING;
+       if (!has_sha1_file(obj->sha1))
+               return;
+       if (parse_tree(tree) < 0)
+               die("bad tree %s", sha1_to_hex(obj->sha1));
+       entry = tree->entries;
+       while (entry) {
+               if (entry->directory)
+                       mark_tree_uninteresting(entry->item.tree);
+               else
+                       mark_blob_uninteresting(entry->item.blob);
+               entry = entry->next;
+       }
+}
+
+static void mark_parents_uninteresting(struct commit *commit)
+{
+       struct commit_list *parents = commit->parents;
+
+       if (tree_objects)
+               mark_tree_uninteresting(commit->tree);
+       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);
+
+               /*
+                * A missing commit is ok iff its parent is marked 
+                * uninteresting.
+                *
+                * We just mark such a thing parsed, so that when
+                * it is popped next time around, we won't be trying
+                * to parse it and get an error.
+                */
+               if (!has_sha1_file(commit->object.sha1))
+                       commit->object.parsed = 1;
+               parents = parents->next;
+       }
+}
+
+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;
+       }
+
+       /*
+        * Ok, go back and mark all the edge trees uninteresting,
+        * since otherwise we can have situations where a parent
+        * that was marked uninteresting (and we never even had
+        * to look at) had lots of objects that we don't want to
+        * include.
+        *
+        * NOTE! This still doesn't mean that the object list is
+        * "correct", since we may end up listing objects that
+        * even older commits (that we don't list) do actually
+        * reference, but it gets us to a minimal list (or very
+        * close) in practice.
+        */
+       if (!tree_objects)
+               return 1;
+
+       while (orig) {
+               struct commit *commit = orig->item;
+               if (!parse_commit(commit) && commit->tree)
+                       mark_tree_uninteresting(commit->tree);
+               orig = orig->next;
+       }
+       return 1;
+}
+
+/*
+ * This is a truly stupid algorithm, but it's only
+ * used for bisection, and we just don't care enough.
+ *
+ * We care just barely enough to avoid recursing for
+ * non-merge entries.
+ */
+static int count_distance(struct commit_list *entry)
+{
+       int nr = 0;
+
+       while (entry) {
+               struct commit *commit = entry->item;
+               struct commit_list *p;
+
+               if (commit->object.flags & (UNINTERESTING | COUNTED))
+                       break;
+               nr++;
+               commit->object.flags |= COUNTED;
+               p = commit->parents;
+               entry = p;
+               if (p) {
+                       p = p->next;
+                       while (p) {
+                               nr += count_distance(p);
+                               p = p->next;
+                       }
+               }
+       }
+       return nr;
+}
+
+static void clear_distance(struct commit_list *list)
+{
+       while (list) {
+               struct commit *commit = list->item;
+               commit->object.flags &= ~COUNTED;
+               list = list->next;
+       }
+}
+
+static struct commit_list *find_bisection(struct commit_list *list)
+{
+       int nr, closest;
+       struct commit_list *p, *best;
+
+       nr = 0;
+       p = list;
+       while (p) {
+               nr++;
+               p = p->next;
+       }
+       closest = 0;
+       best = list;
+
+       p = list;
+       while (p) {
+               int distance = count_distance(p);
+               clear_distance(list);
+               if (nr - distance < distance)
+                       distance = nr - distance;
+               if (distance > closest) {
+                       best = p;
+                       closest = distance;
+               }
+               p = p->next;
+       }
+       if (best)
+               best->next = NULL;
+       return best;
+}
+
+static struct commit_list *limit_list(struct commit_list *list)
+{
+       struct commit_list *newlist = NULL;
+       struct commit_list **p = &newlist;
+       while (list) {
+               struct commit *commit = pop_most_recent_commit(&list, SEEN);
+               struct object *obj = &commit->object;
+
+               if (unpacked && has_sha1_pack(obj->sha1))
+                       obj->flags |= UNINTERESTING;
+               if (obj->flags & UNINTERESTING) {
+                       mark_parents_uninteresting(commit);
+                       if (everybody_uninteresting(list))
+                               break;
+                       continue;
+               }
+               p = &commit_list_insert(commit, p)->next;
+       }
+       if (bisect_list)
+               newlist = find_bisection(newlist);
+       return newlist;
+}
+
+static void add_pending_object(struct object *obj, const char *name)
+{
+       add_object(obj, &pending_objects, name);
+}
+
+static struct commit *get_commit_reference(const char *name, unsigned int flags)
 {
        unsigned char sha1[20];
+       struct object *object;
+
+       if (get_sha1(name, sha1))
+               usage(rev_list_usage);
+       object = parse_object(sha1);
+       if (!object)
+               die("bad object %s", name);
+
+       /*
+        * Tag object? Look what it points to..
+        */
+       while (object->type == tag_type) {
+               struct tag *tag = (struct tag *) object;
+               object->flags |= flags;
+               if (tag_objects && !(object->flags & UNINTERESTING))
+                       add_pending_object(object, tag->tag);
+               object = parse_object(tag->tagged->sha1);
+               if (!object)
+                       die("bad object %s", sha1_to_hex(tag->tagged->sha1));
+       }
+
+       /*
+        * Commit object? Just return it, we'll do all the complex
+        * reachability crud.
+        */
+       if (object->type == commit_type) {
+               struct commit *commit = (struct commit *)object;
+               object->flags |= flags;
+               if (parse_commit(commit) < 0)
+                       die("unable to parse commit %s", name);
+               if (flags & UNINTERESTING)
+                       mark_parents_uninteresting(commit);
+               return commit;
+       }
+
+       /*
+        * Tree object? Either mark it uniniteresting, or add it
+        * to the list of objects to look at later..
+        */
+       if (object->type == tree_type) {
+               struct tree *tree = (struct tree *)object;
+               if (!tree_objects)
+                       return NULL;
+               if (flags & UNINTERESTING) {
+                       mark_tree_uninteresting(tree);
+                       return NULL;
+               }
+               add_pending_object(object, "");
+               return NULL;
+       }
+
+       /*
+        * Blob object? You know the drill by now..
+        */
+       if (object->type == blob_type) {
+               struct blob *blob = (struct blob *)object;
+               if (!blob_objects)
+                       return NULL;
+               if (flags & UNINTERESTING) {
+                       mark_blob_uninteresting(blob);
+                       return NULL;
+               }
+               add_pending_object(object, "");
+               return NULL;
+       }
+       die("%s is unknown object", name);
+}
+
+static void handle_one_commit(struct commit *com, struct commit_list **lst)
+{
+       if (!com || com->object.flags & SEEN)
+               return;
+       com->object.flags |= SEEN;
+       commit_list_insert(com, lst);
+}
+
+
+int main(int argc, char **argv)
+{
        struct commit_list *list = NULL;
-       struct commit *commit;
+       int i, limited = 0;
+
+       setup_git_directory();
+       for (i = 1 ; i < argc; i++) {
+               int flags;
+               char *arg = argv[i];
+               char *dotdot;
+               struct commit *commit;
+
+               if (!strncmp(arg, "--max-count=", 12)) {
+                       max_count = atoi(arg + 12);
+                       continue;
+               }
+               if (!strncmp(arg, "--max-age=", 10)) {
+                       max_age = atoi(arg + 10);
+                       continue;
+               }
+               if (!strncmp(arg, "--min-age=", 10)) {
+                       min_age = atoi(arg + 10);
+                       continue;
+               }
+               if (!strcmp(arg, "--header")) {
+                       verbose_header = 1;
+                       continue;
+               }
+               if (!strncmp(arg, "--pretty", 8)) {
+                       commit_format = get_commit_format(arg+8);
+                       verbose_header = 1;
+                       hdr_termination = '\n';
+                       if (commit_format == CMIT_FMT_ONELINE)
+                               commit_prefix = "";
+                       else
+                               commit_prefix = "commit ";
+                       continue;
+               }
+               if (!strncmp(arg, "--no-merges", 11)) {
+                       no_merges = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--parents")) {
+                       show_parents = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--bisect")) {
+                       bisect_list = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--objects")) {
+                       tag_objects = 1;
+                       tree_objects = 1;
+                       blob_objects = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--unpacked")) {
+                       unpacked = 1;
+                       limited = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--merge-order")) {
+                       merge_order = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--show-breaks")) {
+                       show_breaks = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "--topo-order")) {
+                       topo_order = 1;
+                       limited = 1;
+                       continue;
+               }
+
+               if (show_breaks && !merge_order)
+                       usage(rev_list_usage);
+
+               flags = 0;
+               dotdot = strstr(arg, "..");
+               if (dotdot) {
+                       char *next = dotdot + 2;
+                       struct commit *exclude = NULL;
+                       struct commit *include = NULL;
+                       *dotdot = 0;
+                       exclude = get_commit_reference(arg, UNINTERESTING);
+                       include = get_commit_reference(next, 0);
+                       if (exclude && include) {
+                               limited = 1;
+                               handle_one_commit(exclude, &list);
+                               handle_one_commit(include, &list);
+                               continue;
+                       }
+                       *next = '.';
+               }
+               if (*arg == '^') {
+                       flags = UNINTERESTING;
+                       arg++;
+                       limited = 1;
+               }
+               commit = get_commit_reference(arg, flags);
+               handle_one_commit(commit, &list);
+       }
 
-       if (argc != 2 || get_sha1_hex(argv[1], sha1))
-               usage("rev-list <commit-id>");
+       save_commit_buffer = verbose_header;
 
-       commit = lookup_commit(sha1);
-       if (!commit || parse_commit(commit) < 0)
-               die("bad commit object");
+       if (!merge_order) {             
+               sort_by_date(&list);
+               if (limited)
+                       list = limit_list(list);
+               if (topo_order)
+                       sort_in_topological_order(&list);
+               show_commit_list(list);
+       } else {
+#ifndef NO_OPENSSL
+               if (sort_list_in_merge_order(list, &process_commit)) {
+                       die("merge order sort failed\n");
+               }
+#else
+               die("merge order sort unsupported, OpenSSL not linked");
+#endif
+       }
 
-       commit_list_insert(commit, &list);
-       do {
-               struct commit *commit = pop_most_recent_commit(&list);
-               printf("%s\n", sha1_to_hex(commit->object.sha1));
-       } while (list);
        return 0;
 }