reachable.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "tag.h"
   4 #include "commit.h"
   5 #include "blob.h"
   6 #include "diff.h"
   7 #include "revision.h"
   8 #include "reachable.h"
   9 #include "cache-tree.h"
  10
  11 static void process_blob(struct blob *blob,
  12                          struct object_array *p,
  13                          struct name_path *path,
  14                          const char *name)
  15 {
  16         struct object *obj = &blob->object;
  17
  18         if (!blob)
  19                 die("bad blob object");
  20         if (obj->flags & SEEN)
  21                 return;
  22         obj->flags |= SEEN;
  23         /* Nothing to do, really .. The blob lookup was the important part */
  24 }
  25
  26 static void process_gitlink(const unsigned char *sha1,
  27                             struct object_array *p,
  28                             struct name_path *path,
  29                             const char *name)
  30 {
  31         /* I don't think we want to recurse into this, really. */
  32 }
  33
  34 static void process_tree(struct tree *tree,
  35                          struct object_array *p,
  36                          struct name_path *path,
  37                          const char *name)
  38 {
  39         struct object *obj = &tree->object;
  40         struct tree_desc desc;
  41         struct name_entry entry;
  42         struct name_path me;
  43
  44         if (!tree)
  45                 die("bad tree object");
  46         if (obj->flags & SEEN)
  47                 return;
  48         obj->flags |= SEEN;
  49         if (parse_tree(tree) < 0)
  50                 die("bad tree object %s", sha1_to_hex(obj->sha1));
  51         add_object(obj, p, path, name);
  52         me.up = path;
  53         me.elem = name;
  54         me.elem_len = strlen(name);
  55
  56         init_tree_desc(&desc, tree->buffer, tree->size);
  57
  58         while (tree_entry(&desc, &entry)) {
  59                 if (S_ISDIR(entry.mode))
  60                         process_tree(lookup_tree(entry.sha1), p, &me, entry.path);
  61                 else if (S_ISGITLINK(entry.mode))
  62                         process_gitlink(entry.sha1, p, &me, entry.path);
  63                 else
  64                         process_blob(lookup_blob(entry.sha1), p, &me, entry.path);
  65         }
  66         free(tree->buffer);
  67         tree->buffer = NULL;
  68 }
  69
  70 static void process_tag(struct tag *tag, struct object_array *p, const char *name)
  71 {
  72         struct object *obj = &tag->object;
  73         struct name_path me;
  74
  75         if (obj->flags & SEEN)
  76                 return;
  77         obj->flags |= SEEN;
  78
  79         me.up = NULL;
  80         me.elem = "tag:/";
  81         me.elem_len = 5;
  82
  83         if (parse_tag(tag) < 0)
  84                 die("bad tag object %s", sha1_to_hex(obj->sha1));
  85         if (tag->tagged)
  86                 add_object(tag->tagged, p, NULL, name);
  87 }
  88
  89 static void walk_commit_list(struct rev_info *revs)
  90 {
  91         int i;
  92         struct commit *commit;
  93         struct object_array objects = { 0, 0, NULL };
  94
  95         /* Walk all commits, process their trees */
  96         while ((commit = get_revision(revs)) != NULL)
  97                 process_tree(commit->tree, &objects, NULL, "");
  98
  99         /* Then walk all the pending objects, recursively processing them too */
 100         for (i = 0; i < revs->pending.nr; i++) {
 101                 struct object_array_entry *pending = revs->pending.objects + i;
 102                 struct object *obj = pending->item;
 103                 const char *name = pending->name;
 104                 if (obj->type == OBJ_TAG) {
 105                         process_tag((struct tag *) obj, &objects, name);
 106                         continue;
 107                 }
 108                 if (obj->type == OBJ_TREE) {
 109                         process_tree((struct tree *)obj, &objects, NULL, name);
 110                         continue;
 111                 }
 112                 if (obj->type == OBJ_BLOB) {
 113                         process_blob((struct blob *)obj, &objects, NULL, name);
 114                         continue;
 115                 }
 116                 die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
 117         }
 118 }
 119
 120 static int add_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
 121                 const char *email, unsigned long timestamp, int tz,
 122                 const char *message, void *cb_data)
 123 {
 124         struct object *object;
 125         struct rev_info *revs = (struct rev_info *)cb_data;
 126
 127         object = parse_object(osha1);
 128         if (object)
 129                 add_pending_object(revs, object, "");
 130         object = parse_object(nsha1);
 131         if (object)
 132                 add_pending_object(revs, object, "");
 133         return 0;
 134 }
 135
 136 static int add_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 137 {
 138         struct object *object = parse_object(sha1);
 139         struct rev_info *revs = (struct rev_info *)cb_data;
 140
 141         if (!object)
 142                 die("bad object ref: %s:%s", path, sha1_to_hex(sha1));
 143         add_pending_object(revs, object, "");
 144
 145         return 0;
 146 }
 147
 148 static int add_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 149 {
 150         for_each_reflog_ent(path, add_one_reflog_ent, cb_data);
 151         return 0;
 152 }
 153
 154 static void add_one_tree(const unsigned char *sha1, struct rev_info *revs)
 155 {
 156         struct tree *tree = lookup_tree(sha1);
 157         if (tree)
 158                 add_pending_object(revs, &tree->object, "");
 159 }
 160
 161 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs)
 162 {
 163         int i;
 164
 165         if (it->entry_count >= 0)
 166                 add_one_tree(it->sha1, revs);
 167         for (i = 0; i < it->subtree_nr; i++)
 168                 add_cache_tree(it->down[i]->cache_tree, revs);
 169 }
 170
 171 static void add_cache_refs(struct rev_info *revs)
 172 {
 173         int i;
 174
 175         read_cache();
 176         for (i = 0; i < active_nr; i++) {
 177                 /*
 178                  * The index can contain blobs and GITLINKs, GITLINKs are hashes
 179                  * that don't actually point to objects in the repository, it's
 180                  * almost guaranteed that they are NOT blobs, so we don't call
 181                  * lookup_blob() on them, to avoid populating the hash table
 182                  * with invalid information
 183                  */
 184                 if (S_ISGITLINK(active_cache[i]->ce_mode))
 185                         continue;
 186
 187                 lookup_blob(active_cache[i]->sha1);
 188                 /*
 189                  * We could add the blobs to the pending list, but quite
 190                  * frankly, we don't care. Once we've looked them up, and
 191                  * added them as objects, we've really done everything
 192                  * there is to do for a blob
 193                  */
 194         }
 195         if (active_cache_tree)
 196                 add_cache_tree(active_cache_tree, revs);
 197 }
 198
 199 void mark_reachable_objects(struct rev_info *revs, int mark_reflog)
 200 {
 201         /*
 202          * Set up revision parsing, and mark us as being interested
 203          * in all object types, not just commits.
 204          */
 205         revs->tag_objects = 1;
 206         revs->blob_objects = 1;
 207         revs->tree_objects = 1;
 208
 209         /* Add all refs from the index file */
 210         add_cache_refs(revs);
 211
 212         /* Add all external refs */
 213         for_each_ref(add_one_ref, revs);
 214
 215         /* Add all reflog info */
 216         if (mark_reflog)
 217                 for_each_reflog(add_one_reflog, revs);
 218
 219         /*
 220          * Set up the revision walk - this will move all commits
 221          * from the pending list to the commit walking list.
 222          */
 223         if (prepare_revision_walk(revs))
 224                 die("revision walk setup failed");
 225         walk_commit_list(revs);
 226 }