976a5a459c466b05b2caf27a58a979598daf05d3
[git/git.git] / fetch.c
1 #include "fetch.h"
2
3 #include "cache.h"
4 #include "commit.h"
5 #include "tree.h"
6 #include "tree-walk.h"
7 #include "tag.h"
8 #include "blob.h"
9 #include "refs.h"
10
11 const char *write_ref = NULL;
12
13 int get_tree = 0;
14 int get_history = 0;
15 int get_all = 0;
16 int get_verbosely = 0;
17 int get_recover = 0;
18 static unsigned char current_commit_sha1[20];
19
20 void pull_say(const char *fmt, const char *hex)
21 {
22 if (get_verbosely)
23 fprintf(stderr, fmt, hex);
24 }
25
26 static void report_missing(const char *what, const unsigned char *missing)
27 {
28 char missing_hex[41];
29
30 strcpy(missing_hex, sha1_to_hex(missing));;
31 fprintf(stderr,
32 "Cannot obtain needed %s %s\nwhile processing commit %s.\n",
33 what, missing_hex, sha1_to_hex(current_commit_sha1));
34 }
35
36 static int process(struct object *obj);
37
38 static int process_tree(struct tree *tree)
39 {
40 struct tree_desc desc;
41
42 if (parse_tree(tree))
43 return -1;
44
45 desc.buf = tree->buffer;
46 desc.size = tree->size;
47 while (desc.size) {
48 unsigned mode;
49 const char *name;
50 const unsigned char *sha1;
51
52 sha1 = tree_entry_extract(&desc, &name, &mode);
53 update_tree_entry(&desc);
54
55 if (S_ISDIR(mode)) {
56 struct tree *tree = lookup_tree(sha1);
57 process_tree(tree);
58 } else {
59 struct blob *blob = lookup_blob(sha1);
60 process(&blob->object);
61 }
62 }
63 free(tree->buffer);
64 tree->buffer = NULL;
65 tree->size = 0;
66 return 0;
67 }
68
69 #define COMPLETE (1U << 0)
70 #define SEEN (1U << 1)
71 #define TO_SCAN (1U << 2)
72
73 static struct commit_list *complete = NULL;
74
75 static int process_commit(struct commit *commit)
76 {
77 if (parse_commit(commit))
78 return -1;
79
80 while (complete && complete->item->date >= commit->date) {
81 pop_most_recent_commit(&complete, COMPLETE);
82 }
83
84 if (commit->object.flags & COMPLETE)
85 return 0;
86
87 memcpy(current_commit_sha1, commit->object.sha1, 20);
88
89 pull_say("walk %s\n", sha1_to_hex(commit->object.sha1));
90
91 if (get_tree) {
92 if (process(&commit->tree->object))
93 return -1;
94 if (!get_all)
95 get_tree = 0;
96 }
97 if (get_history) {
98 struct commit_list *parents = commit->parents;
99 for (; parents; parents = parents->next) {
100 if (process(&parents->item->object))
101 return -1;
102 }
103 }
104 return 0;
105 }
106
107 static int process_tag(struct tag *tag)
108 {
109 if (parse_tag(tag))
110 return -1;
111 return process(tag->tagged);
112 }
113
114 static struct object_list *process_queue = NULL;
115 static struct object_list **process_queue_end = &process_queue;
116
117 static int process_object(struct object *obj)
118 {
119 if (obj->type == commit_type) {
120 if (process_commit((struct commit *)obj))
121 return -1;
122 return 0;
123 }
124 if (obj->type == tree_type) {
125 if (process_tree((struct tree *)obj))
126 return -1;
127 return 0;
128 }
129 if (obj->type == blob_type) {
130 return 0;
131 }
132 if (obj->type == tag_type) {
133 if (process_tag((struct tag *)obj))
134 return -1;
135 return 0;
136 }
137 return error("Unable to determine requirements "
138 "of type %s for %s",
139 obj->type, sha1_to_hex(obj->sha1));
140 }
141
142 static int process(struct object *obj)
143 {
144 if (obj->flags & SEEN)
145 return 0;
146 obj->flags |= SEEN;
147
148 if (has_sha1_file(obj->sha1)) {
149 /* We already have it, so we should scan it now. */
150 obj->flags |= TO_SCAN;
151 } else {
152 if (obj->flags & COMPLETE)
153 return 0;
154 prefetch(obj->sha1);
155 }
156
157 object_list_insert(obj, process_queue_end);
158 process_queue_end = &(*process_queue_end)->next;
159 return 0;
160 }
161
162 static int loop(void)
163 {
164 struct object_list *elem;
165
166 while (process_queue) {
167 struct object *obj = process_queue->item;
168 elem = process_queue;
169 process_queue = elem->next;
170 free(elem);
171 if (!process_queue)
172 process_queue_end = &process_queue;
173
174 /* If we are not scanning this object, we placed it in
175 * the queue because we needed to fetch it first.
176 */
177 if (! (obj->flags & TO_SCAN)) {
178 if (fetch(obj->sha1)) {
179 report_missing(obj->type
180 ? obj->type
181 : "object", obj->sha1);
182 return -1;
183 }
184 }
185 if (!obj->type)
186 parse_object(obj->sha1);
187 if (process_object(obj))
188 return -1;
189 }
190 return 0;
191 }
192
193 static int interpret_target(char *target, unsigned char *sha1)
194 {
195 if (!get_sha1_hex(target, sha1))
196 return 0;
197 if (!check_ref_format(target)) {
198 if (!fetch_ref(target, sha1)) {
199 return 0;
200 }
201 }
202 return -1;
203 }
204
205 static int mark_complete(const char *path, const unsigned char *sha1)
206 {
207 struct commit *commit = lookup_commit_reference_gently(sha1, 1);
208 if (commit) {
209 commit->object.flags |= COMPLETE;
210 insert_by_date(commit, &complete);
211 }
212 return 0;
213 }
214
215 int pull(char *target)
216 {
217 unsigned char sha1[20];
218
219 save_commit_buffer = 0;
220 track_object_refs = 0;
221
222 if (!get_recover)
223 for_each_ref(mark_complete);
224
225 if (interpret_target(target, sha1))
226 return error("Could not interpret %s as something to pull",
227 target);
228 if (process(lookup_unknown_object(sha1)))
229 return -1;
230 if (loop())
231 return -1;
232
233 if (write_ref)
234 write_ref_sha1_unlocked(write_ref, sha1);
235 return 0;
236 }