Implement first draft of DNS-SD support in git-daemon
[git] / 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 #include "progress.h"
11
12 struct connectivity_progress {
13         struct progress *progress;
14         unsigned long count;
15 };
16
17 static void update_progress(struct connectivity_progress *cp)
18 {
19         cp->count++;
20         if ((cp->count & 1023) == 0)
21                 display_progress(cp->progress, cp->count);
22 }
23
24 static void process_blob(struct blob *blob,
25                          struct object_array *p,
26                          struct name_path *path,
27                          const char *name,
28                          struct connectivity_progress *cp)
29 {
30         struct object *obj = &blob->object;
31
32         if (!blob)
33                 die("bad blob object");
34         if (obj->flags & SEEN)
35                 return;
36         obj->flags |= SEEN;
37         update_progress(cp);
38         /* Nothing to do, really .. The blob lookup was the important part */
39 }
40
41 static void process_gitlink(const unsigned char *sha1,
42                             struct object_array *p,
43                             struct name_path *path,
44                             const char *name)
45 {
46         /* I don't think we want to recurse into this, really. */
47 }
48
49 static void process_tree(struct tree *tree,
50                          struct object_array *p,
51                          struct name_path *path,
52                          const char *name,
53                          struct connectivity_progress *cp)
54 {
55         struct object *obj = &tree->object;
56         struct tree_desc desc;
57         struct name_entry entry;
58         struct name_path me;
59
60         if (!tree)
61                 die("bad tree object");
62         if (obj->flags & SEEN)
63                 return;
64         obj->flags |= SEEN;
65         update_progress(cp);
66         if (parse_tree(tree) < 0)
67                 die("bad tree object %s", sha1_to_hex(obj->sha1));
68         add_object(obj, p, path, name);
69         me.up = path;
70         me.elem = name;
71         me.elem_len = strlen(name);
72
73         init_tree_desc(&desc, tree->buffer, tree->size);
74
75         while (tree_entry(&desc, &entry)) {
76                 if (S_ISDIR(entry.mode))
77                         process_tree(lookup_tree(entry.sha1), p, &me, entry.path, cp);
78                 else if (S_ISGITLINK(entry.mode))
79                         process_gitlink(entry.sha1, p, &me, entry.path);
80                 else
81                         process_blob(lookup_blob(entry.sha1), p, &me, entry.path, cp);
82         }
83         free_tree_buffer(tree);
84 }
85
86 static void process_tag(struct tag *tag, struct object_array *p,
87                         const char *name, struct connectivity_progress *cp)
88 {
89         struct object *obj = &tag->object;
90
91         if (obj->flags & SEEN)
92                 return;
93         obj->flags |= SEEN;
94         update_progress(cp);
95
96         if (parse_tag(tag) < 0)
97                 die("bad tag object %s", sha1_to_hex(obj->sha1));
98         if (tag->tagged)
99                 add_object(tag->tagged, p, NULL, name);
100 }
101
102 static void walk_commit_list(struct rev_info *revs,
103                              struct connectivity_progress *cp)
104 {
105         int i;
106         struct commit *commit;
107         struct object_array objects = OBJECT_ARRAY_INIT;
108
109         /* Walk all commits, process their trees */
110         while ((commit = get_revision(revs)) != NULL) {
111                 process_tree(commit->tree, &objects, NULL, "", cp);
112                 update_progress(cp);
113         }
114
115         /* Then walk all the pending objects, recursively processing them too */
116         for (i = 0; i < revs->pending.nr; i++) {
117                 struct object_array_entry *pending = revs->pending.objects + i;
118                 struct object *obj = pending->item;
119                 const char *name = pending->name;
120                 if (obj->type == OBJ_TAG) {
121                         process_tag((struct tag *) obj, &objects, name, cp);
122                         continue;
123                 }
124                 if (obj->type == OBJ_TREE) {
125                         process_tree((struct tree *)obj, &objects, NULL, name, cp);
126                         continue;
127                 }
128                 if (obj->type == OBJ_BLOB) {
129                         process_blob((struct blob *)obj, &objects, NULL, name, cp);
130                         continue;
131                 }
132                 die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
133         }
134 }
135
136 static int add_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
137                 const char *email, unsigned long timestamp, int tz,
138                 const char *message, void *cb_data)
139 {
140         struct object *object;
141         struct rev_info *revs = (struct rev_info *)cb_data;
142
143         object = parse_object(osha1);
144         if (object)
145                 add_pending_object(revs, object, "");
146         object = parse_object(nsha1);
147         if (object)
148                 add_pending_object(revs, object, "");
149         return 0;
150 }
151
152 static int add_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
153 {
154         struct object *object = parse_object_or_die(sha1, path);
155         struct rev_info *revs = (struct rev_info *)cb_data;
156
157         add_pending_object(revs, object, "");
158
159         return 0;
160 }
161
162 static int add_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
163 {
164         for_each_reflog_ent(path, add_one_reflog_ent, cb_data);
165         return 0;
166 }
167
168 static void add_one_tree(const unsigned char *sha1, struct rev_info *revs)
169 {
170         struct tree *tree = lookup_tree(sha1);
171         if (tree)
172                 add_pending_object(revs, &tree->object, "");
173 }
174
175 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs)
176 {
177         int i;
178
179         if (it->entry_count >= 0)
180                 add_one_tree(it->sha1, revs);
181         for (i = 0; i < it->subtree_nr; i++)
182                 add_cache_tree(it->down[i]->cache_tree, revs);
183 }
184
185 static void add_cache_refs(struct rev_info *revs)
186 {
187         int i;
188
189         read_cache();
190         for (i = 0; i < active_nr; i++) {
191                 /*
192                  * The index can contain blobs and GITLINKs, GITLINKs are hashes
193                  * that don't actually point to objects in the repository, it's
194                  * almost guaranteed that they are NOT blobs, so we don't call
195                  * lookup_blob() on them, to avoid populating the hash table
196                  * with invalid information
197                  */
198                 if (S_ISGITLINK(active_cache[i]->ce_mode))
199                         continue;
200
201                 lookup_blob(active_cache[i]->sha1);
202                 /*
203                  * We could add the blobs to the pending list, but quite
204                  * frankly, we don't care. Once we've looked them up, and
205                  * added them as objects, we've really done everything
206                  * there is to do for a blob
207                  */
208         }
209         if (active_cache_tree)
210                 add_cache_tree(active_cache_tree, revs);
211 }
212
213 void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
214                             struct progress *progress)
215 {
216         struct connectivity_progress cp;
217
218         /*
219          * Set up revision parsing, and mark us as being interested
220          * in all object types, not just commits.
221          */
222         revs->tag_objects = 1;
223         revs->blob_objects = 1;
224         revs->tree_objects = 1;
225
226         /* Add all refs from the index file */
227         add_cache_refs(revs);
228
229         /* Add all external refs */
230         for_each_ref(add_one_ref, revs);
231
232         /* Add all reflog info */
233         if (mark_reflog)
234                 for_each_reflog(add_one_reflog, revs);
235
236         cp.progress = progress;
237         cp.count = 0;
238
239         /*
240          * Set up the revision walk - this will move all commits
241          * from the pending list to the commit walking list.
242          */
243         if (prepare_revision_walk(revs))
244                 die("revision walk setup failed");
245         walk_commit_list(revs, &cp);
246         display_progress(cp.progress, cp.count);
247 }