Avoid wasting memory while keeping track of what we have during fetch.
[git/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 }