Documentation: diff can compare blobs
[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
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 = OBJECT_ARRAY_INIT;
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 }