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