Avoid wasting memory while keeping track of what we have during fetch.
[git.git] / fetch.c
1 #include "fetch.h"
2
3 #include "cache.h"
4 #include "commit.h"
5 #include "tree.h"
6 #include "tag.h"
7 #include "blob.h"
8 #include "refs.h"
9
10 const char *write_ref = NULL;
11
12 const unsigned char *current_ref = NULL;
13
14 int get_tree = 0;
15 int get_history = 0;
16 int get_all = 0;
17 int get_verbosely = 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 make_sure_we_have_it(const char *what, unsigned char *sha1)
37 {
38         int status = 0;
39
40         if (!has_sha1_file(sha1)) {
41                 status = fetch(sha1);
42                 if (status && what)
43                         report_missing(what, sha1);
44         }
45         return status;
46 }
47
48 static int process(unsigned char *sha1, const char *type);
49
50 static int process_tree(struct tree *tree)
51 {
52         struct tree_entry_list *entries;
53
54         if (parse_tree(tree))
55                 return -1;
56
57         for (entries = tree->entries; entries; entries = entries->next) {
58                 if (process(entries->item.any->sha1,
59                             entries->directory ? tree_type : blob_type))
60                         return -1;
61         }
62         return 0;
63 }
64
65 struct commit_list *complete = NULL;
66
67 static int process_commit(struct commit *commit)
68 {
69         if (parse_commit(commit))
70                 return -1;
71
72         while (complete && complete->item->date >= commit->date) {
73                 pop_most_recent_commit(&complete, 1);
74         }
75                 
76
77         if (commit->object.flags & 1)
78                 return 0;
79
80         memcpy(current_commit_sha1, commit->object.sha1, 20);
81
82         if (get_tree) {
83                 if (process(commit->tree->object.sha1, tree_type))
84                         return -1;
85                 if (!get_all)
86                         get_tree = 0;
87         }
88         if (get_history) {
89                 struct commit_list *parents = commit->parents;
90                 for (; parents; parents = parents->next) {
91                         if (process(parents->item->object.sha1,
92                                     commit_type))
93                                 return -1;
94                 }
95         }
96         return 0;
97 }
98
99 static int process_tag(struct tag *tag)
100 {
101         if (parse_tag(tag))
102                 return -1;
103         return process(tag->tagged->sha1, NULL);
104 }
105
106 static struct object_list *process_queue = NULL;
107 static struct object_list **process_queue_end = &process_queue;
108
109 static int process_object(struct object *obj)
110 {
111         if (obj->type == commit_type) {
112                 if (process_commit((struct commit *)obj))
113                         return -1;
114                 return 0;
115         }
116         if (obj->type == tree_type) {
117                 if (process_tree((struct tree *)obj))
118                         return -1;
119                 return 0;
120         }
121         if (obj->type == blob_type) {
122                 return 0;
123         }
124         if (obj->type == tag_type) {
125                 if (process_tag((struct tag *)obj))
126                         return -1;
127                 return 0;
128         }
129         return error("Unable to determine requirements "
130                      "of type %s for %s",
131                      obj->type, sha1_to_hex(obj->sha1));
132 }
133
134 static int process(unsigned char *sha1, const char *type)
135 {
136         struct object *obj = lookup_object_type(sha1, type);
137
138         if (has_sha1_file(sha1)) {
139                 parse_object(sha1);
140                 /* We already have it, so we should scan it now. */
141                 return process_object(obj);
142         }
143         if (object_list_contains(process_queue, obj))
144                 return 0;
145         object_list_insert(obj, process_queue_end);
146         process_queue_end = &(*process_queue_end)->next;
147
148         //fprintf(stderr, "prefetch %s\n", sha1_to_hex(sha1));
149         prefetch(sha1);
150                 
151         return 0;
152 }
153
154 static int loop(void)
155 {
156         while (process_queue) {
157                 struct object *obj = process_queue->item;
158                 /*
159                 fprintf(stderr, "%d objects to pull\n", 
160                         object_list_length(process_queue));
161                 */
162                 process_queue = process_queue->next;
163                 if (!process_queue)
164                         process_queue_end = &process_queue;
165
166                 //fprintf(stderr, "fetch %s\n", sha1_to_hex(obj->sha1));
167                 
168                 if (make_sure_we_have_it(obj->type ? obj->type : "object", 
169                                          obj->sha1))
170                         return -1;
171                 if (!obj->type)
172                         parse_object(obj->sha1);
173                 if (process_object(obj))
174                         return -1;
175         }
176         return 0;
177 }
178
179 static int interpret_target(char *target, unsigned char *sha1)
180 {
181         if (!get_sha1_hex(target, sha1))
182                 return 0;
183         if (!check_ref_format(target)) {
184                 if (!fetch_ref(target, sha1)) {
185                         return 0;
186                 }
187         }
188         return -1;
189 }
190
191 static int mark_complete(const char *path, const unsigned char *sha1)
192 {
193         struct object *obj = parse_object(sha1);
194         while (obj->type == tag_type) {
195                 obj = ((struct tag *) obj)->tagged;
196                 parse_object(obj->sha1);
197         }
198         if (obj->type == commit_type) {
199                 obj->flags |= 1;
200                 insert_by_date((struct commit *) obj, &complete);
201         }
202         return 0;
203 }
204
205 int pull(char *target)
206 {
207         unsigned char sha1[20];
208         int fd = -1;
209
210         save_commit_buffer = 0;
211         if (write_ref && current_ref) {
212                 fd = lock_ref_sha1(write_ref, current_ref);
213                 if (fd < 0)
214                         return -1;
215         }
216
217         for_each_ref(mark_complete);
218
219         if (interpret_target(target, sha1))
220                 return error("Could not interpret %s as something to pull",
221                              target);
222         if (process(sha1, NULL))
223                 return -1;
224         if (loop())
225                 return -1;
226         
227         if (write_ref) {
228                 if (current_ref) {
229                         write_ref_sha1(write_ref, fd, sha1);
230                 } else {
231                         write_ref_sha1_unlocked(write_ref, sha1);
232                 }
233         }
234         return 0;
235 }