git-pull: allow pulling into an empty repository
[git] / local-fetch.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include "cache.h"
5 #include "commit.h"
6 #include "fetch.h"
7
8 static int use_link;
9 static int use_symlink;
10 static int use_filecopy = 1;
11 static int commits_on_stdin;
12
13 static const char *path; /* "Remote" git repository */
14
15 void prefetch(unsigned char *sha1)
16 {
17 }
18
19 static struct packed_git *packs;
20
21 static void setup_index(unsigned char *sha1)
22 {
23         struct packed_git *new_pack;
24         char filename[PATH_MAX];
25         strcpy(filename, path);
26         strcat(filename, "/objects/pack/pack-");
27         strcat(filename, sha1_to_hex(sha1));
28         strcat(filename, ".idx");
29         new_pack = parse_pack_index_file(sha1, filename);
30         new_pack->next = packs;
31         packs = new_pack;
32 }
33
34 static int setup_indices(void)
35 {
36         DIR *dir;
37         struct dirent *de;
38         char filename[PATH_MAX];
39         unsigned char sha1[20];
40         sprintf(filename, "%s/objects/pack/", path);
41         dir = opendir(filename);
42         if (!dir)
43                 return -1;
44         while ((de = readdir(dir)) != NULL) {
45                 int namelen = strlen(de->d_name);
46                 if (namelen != 50 ||
47                     !has_extension(de->d_name, ".pack"))
48                         continue;
49                 get_sha1_hex(de->d_name + 5, sha1);
50                 setup_index(sha1);
51         }
52         closedir(dir);
53         return 0;
54 }
55
56 static int copy_file(const char *source, char *dest, const char *hex,
57                      int warn_if_not_exists)
58 {
59         safe_create_leading_directories(dest);
60         if (use_link) {
61                 if (!link(source, dest)) {
62                         pull_say("link %s\n", hex);
63                         return 0;
64                 }
65                 /* If we got ENOENT there is no point continuing. */
66                 if (errno == ENOENT) {
67                         if (warn_if_not_exists)
68                                 fprintf(stderr, "does not exist %s\n", source);
69                         return -1;
70                 }
71         }
72         if (use_symlink) {
73                 struct stat st;
74                 if (stat(source, &st)) {
75                         if (!warn_if_not_exists && errno == ENOENT)
76                                 return -1;
77                         fprintf(stderr, "cannot stat %s: %s\n", source,
78                                 strerror(errno));
79                         return -1;
80                 }
81                 if (!symlink(source, dest)) {
82                         pull_say("symlink %s\n", hex);
83                         return 0;
84                 }
85         }
86         if (use_filecopy) {
87                 int ifd, ofd, status = 0;
88
89                 ifd = open(source, O_RDONLY);
90                 if (ifd < 0) {
91                         if (!warn_if_not_exists && errno == ENOENT)
92                                 return -1;
93                         fprintf(stderr, "cannot open %s\n", source);
94                         return -1;
95                 }
96                 ofd = open(dest, O_WRONLY | O_CREAT | O_EXCL, 0666);
97                 if (ofd < 0) {
98                         fprintf(stderr, "cannot open %s\n", dest);
99                         close(ifd);
100                         return -1;
101                 }
102                 status = copy_fd(ifd, ofd);
103                 close(ofd);
104                 if (status)
105                         fprintf(stderr, "cannot write %s\n", dest);
106                 else
107                         pull_say("copy %s\n", hex);
108                 return status;
109         }
110         fprintf(stderr, "failed to copy %s with given copy methods.\n", hex);
111         return -1;
112 }
113
114 static int fetch_pack(const unsigned char *sha1)
115 {
116         struct packed_git *target;
117         char filename[PATH_MAX];
118         if (setup_indices())
119                 return -1;
120         target = find_sha1_pack(sha1, packs);
121         if (!target)
122                 return error("Couldn't find %s: not separate or in any pack", 
123                              sha1_to_hex(sha1));
124         if (get_verbosely) {
125                 fprintf(stderr, "Getting pack %s\n",
126                         sha1_to_hex(target->sha1));
127                 fprintf(stderr, " which contains %s\n",
128                         sha1_to_hex(sha1));
129         }
130         sprintf(filename, "%s/objects/pack/pack-%s.pack", 
131                 path, sha1_to_hex(target->sha1));
132         copy_file(filename, sha1_pack_name(target->sha1),
133                   sha1_to_hex(target->sha1), 1);
134         sprintf(filename, "%s/objects/pack/pack-%s.idx", 
135                 path, sha1_to_hex(target->sha1));
136         copy_file(filename, sha1_pack_index_name(target->sha1),
137                   sha1_to_hex(target->sha1), 1);
138         install_packed_git(target);
139         return 0;
140 }
141
142 static int fetch_file(const unsigned char *sha1)
143 {
144         static int object_name_start = -1;
145         static char filename[PATH_MAX];
146         char *hex = sha1_to_hex(sha1);
147         char *dest_filename = sha1_file_name(sha1);
148
149         if (object_name_start < 0) {
150                 strcpy(filename, path); /* e.g. git.git */
151                 strcat(filename, "/objects/");
152                 object_name_start = strlen(filename);
153         }
154         filename[object_name_start+0] = hex[0];
155         filename[object_name_start+1] = hex[1];
156         filename[object_name_start+2] = '/';
157         strcpy(filename + object_name_start + 3, hex + 2);
158         return copy_file(filename, dest_filename, hex, 0);
159 }
160
161 int fetch(unsigned char *sha1)
162 {
163         if (has_sha1_file(sha1))
164                 return 0;
165         else
166                 return fetch_file(sha1) && fetch_pack(sha1);
167 }
168
169 int fetch_ref(char *ref, unsigned char *sha1)
170 {
171         static int ref_name_start = -1;
172         static char filename[PATH_MAX];
173         static char hex[41];
174         int ifd;
175
176         if (ref_name_start < 0) {
177                 sprintf(filename, "%s/refs/", path);
178                 ref_name_start = strlen(filename);
179         }
180         strcpy(filename + ref_name_start, ref);
181         ifd = open(filename, O_RDONLY);
182         if (ifd < 0) {
183                 close(ifd);
184                 fprintf(stderr, "cannot open %s\n", filename);
185                 return -1;
186         }
187         if (read(ifd, hex, 40) != 40 || get_sha1_hex(hex, sha1)) {
188                 close(ifd);
189                 fprintf(stderr, "cannot read from %s\n", filename);
190                 return -1;
191         }
192         close(ifd);
193         pull_say("ref %s\n", sha1_to_hex(sha1));
194         return 0;
195 }
196
197 static const char local_pull_usage[] =
198 "git-local-fetch [-c] [-t] [-a] [-v] [-w filename] [--recover] [-l] [-s] [-n] [--stdin] commit-id path";
199
200 /*
201  * By default we only use file copy.
202  * If -l is specified, a hard link is attempted.
203  * If -s is specified, then a symlink is attempted.
204  * If -n is _not_ specified, then a regular file-to-file copy is done.
205  */
206 int main(int argc, const char **argv)
207 {
208         int commits;
209         const char **write_ref = NULL;
210         char **commit_id;
211         int arg = 1;
212
213         setup_ident();
214         setup_git_directory();
215         git_config(git_default_config);
216
217         while (arg < argc && argv[arg][0] == '-') {
218                 if (argv[arg][1] == 't')
219                         get_tree = 1;
220                 else if (argv[arg][1] == 'c')
221                         get_history = 1;
222                 else if (argv[arg][1] == 'a') {
223                         get_all = 1;
224                         get_tree = 1;
225                         get_history = 1;
226                 }
227                 else if (argv[arg][1] == 'l')
228                         use_link = 1;
229                 else if (argv[arg][1] == 's')
230                         use_symlink = 1;
231                 else if (argv[arg][1] == 'n')
232                         use_filecopy = 0;
233                 else if (argv[arg][1] == 'v')
234                         get_verbosely = 1;
235                 else if (argv[arg][1] == 'w')
236                         write_ref = &argv[++arg];
237                 else if (!strcmp(argv[arg], "--recover"))
238                         get_recover = 1;
239                 else if (!strcmp(argv[arg], "--stdin"))
240                         commits_on_stdin = 1;
241                 else
242                         usage(local_pull_usage);
243                 arg++;
244         }
245         if (argc < arg + 2 - commits_on_stdin)
246                 usage(local_pull_usage);
247         if (commits_on_stdin) {
248                 commits = pull_targets_stdin(&commit_id, &write_ref);
249         } else {
250                 commit_id = (char **) &argv[arg++];
251                 commits = 1;
252         }
253         path = argv[arg];
254
255         if (pull(commits, commit_id, write_ref, path))
256                 return 1;
257
258         if (commits_on_stdin)
259                 pull_targets_free(commits, commit_id, write_ref);
260
261         return 0;
262 }