Add explanation why we do not allow to sparse checkout to empty working tree
[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
74         if (obj->flags & SEEN)
75                 return;
76         obj->flags |= SEEN;
77
78         if (parse_tag(tag) < 0)
79                 die("bad tag object %s", sha1_to_hex(obj->sha1));
80         if (tag->tagged)
81                 add_object(tag->tagged, p, NULL, name);
82 }
83
84 static void walk_commit_list(struct rev_info *revs)
85 {
86         int i;
87         struct commit *commit;
88         struct object_array objects = OBJECT_ARRAY_INIT;
89
90         /* Walk all commits, process their trees */
91         while ((commit = get_revision(revs)) != NULL)
92                 process_tree(commit->tree, &objects, NULL, "");
93
94         /* Then walk all the pending objects, recursively processing them too */
95         for (i = 0; i < revs->pending.nr; i++) {
96                 struct object_array_entry *pending = revs->pending.objects + i;
97                 struct object *obj = pending->item;
98                 const char *name = pending->name;
99                 if (obj->type == OBJ_TAG) {
100                         process_tag((struct tag *) obj, &objects, name);
101                         continue;
102                 }
103                 if (obj->type == OBJ_TREE) {
104                         process_tree((struct tree *)obj, &objects, NULL, name);
105                         continue;
106                 }
107                 if (obj->type == OBJ_BLOB) {
108                         process_blob((struct blob *)obj, &objects, NULL, name);
109                         continue;
110                 }
111                 die("unknown pending object %s (%s)", sha1_to_hex(obj->sha1), name);
112         }
113 }
114
115 static int add_one_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
116                 const char *email, unsigned long timestamp, int tz,
117                 const char *message, void *cb_data)
118 {
119         struct object *object;
120         struct rev_info *revs = (struct rev_info *)cb_data;
121
122         object = parse_object(osha1);
123         if (object)
124                 add_pending_object(revs, object, "");
125         object = parse_object(nsha1);
126         if (object)
127                 add_pending_object(revs, object, "");
128         return 0;
129 }
130
131 static int add_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
132 {
133         struct object *object = parse_object(sha1);
134         struct rev_info *revs = (struct rev_info *)cb_data;
135
136         if (!object)
137                 die("bad object ref: %s:%s", path, sha1_to_hex(sha1));
138         add_pending_object(revs, object, "");
139
140         return 0;
141 }
142
143 static int add_one_reflog(const char *path, const unsigned char *sha1, int flag, void *cb_data)
144 {
145         for_each_reflog_ent(path, add_one_reflog_ent, cb_data);
146         return 0;
147 }
148
149 static void add_one_tree(const unsigned char *sha1, struct rev_info *revs)
150 {
151         struct tree *tree = lookup_tree(sha1);
152         if (tree)
153                 add_pending_object(revs, &tree->object, "");
154 }
155
156 static void add_cache_tree(struct cache_tree *it, struct rev_info *revs)
157 {
158         int i;
159
160         if (it->entry_count >= 0)
161                 add_one_tree(it->sha1, revs);
162         for (i = 0; i < it->subtree_nr; i++)
163                 add_cache_tree(it->down[i]->cache_tree, revs);
164 }
165
166 static void add_cache_refs(struct rev_info *revs)
167 {
168         int i;
169
170         read_cache();
171         for (i = 0; i < active_nr; i++) {
172                 /*
173                  * The index can contain blobs and GITLINKs, GITLINKs are hashes
174                  * that don't actually point to objects in the repository, it's
175                  * almost guaranteed that they are NOT blobs, so we don't call
176                  * lookup_blob() on them, to avoid populating the hash table
177                  * with invalid information
178                  */
179                 if (S_ISGITLINK(active_cache[i]->ce_mode))
180                         continue;
181
182                 lookup_blob(active_cache[i]->sha1);
183                 /*
184                  * We could add the blobs to the pending list, but quite
185                  * frankly, we don't care. Once we've looked them up, and
186                  * added them as objects, we've really done everything
187                  * there is to do for a blob
188                  */
189         }
190         if (active_cache_tree)
191                 add_cache_tree(active_cache_tree, revs);
192 }
193
194 void mark_reachable_objects(struct rev_info *revs, int mark_reflog)
195 {
196         /*
197          * Set up revision parsing, and mark us as being interested
198          * in all object types, not just commits.
199          */
200         revs->tag_objects = 1;
201         revs->blob_objects = 1;
202         revs->tree_objects = 1;
203
204         /* Add all refs from the index file */
205         add_cache_refs(revs);
206
207         /* Add all external refs */
208         for_each_ref(add_one_ref, revs);
209
210         /* Add all reflog info */
211         if (mark_reflog)
212                 for_each_reflog(add_one_reflog, revs);
213
214         /*
215          * Set up the revision walk - this will move all commits
216          * from the pending list to the commit walking list.
217          */
218         if (prepare_revision_walk(revs))
219                 die("revision walk setup failed");
220         walk_commit_list(revs);
221 }