git-tag: update usage string and documentation.
[git.git] / upload-pack.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4
5 static const char upload_pack_usage[] = "git-upload-pack <dir>";
6
7 #define MAX_HAS (16)
8 #define MAX_NEEDS (256)
9 static int nr_has = 0, nr_needs = 0;
10 static unsigned char has_sha1[MAX_HAS][20];
11 static unsigned char needs_sha1[MAX_NEEDS][20];
12
13 static int strip(char *line, int len)
14 {
15         if (len && line[len-1] == '\n')
16                 line[--len] = 0;
17         return len;
18 }
19
20 static void create_pack_file(void)
21 {
22         int fd[2];
23         pid_t pid;
24
25         if (pipe(fd) < 0)
26                 die("git-upload-pack: unable to create pipe");
27         pid = fork();
28         if (pid < 0)
29                 die("git-upload-pack: unable to fork git-rev-list");
30
31         if (!pid) {
32                 int i;
33                 int args;
34                 char **argv;
35                 char *buf;
36                 char **p;
37
38                 if (MAX_NEEDS <= nr_needs)
39                         args = nr_has + 10;
40                 else
41                         args = nr_has + nr_needs + 5;
42                 argv = xmalloc(args * sizeof(char *));
43                 buf = xmalloc(args * 45);
44                 p = argv;
45
46                 dup2(fd[1], 1);
47                 close(0);
48                 close(fd[0]);
49                 close(fd[1]);
50                 *p++ = "git-rev-list";
51                 *p++ = "--objects";
52                 if (MAX_NEEDS <= nr_needs)
53                         *p++ = "--all";
54                 else {
55                         for (i = 0; i < nr_needs; i++) {
56                                 *p++ = buf;
57                                 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
58                                 buf += 41;
59                         }
60                 }
61                 for (i = 0; i < nr_has; i++) {
62                         *p++ = buf;
63                         *buf++ = '^';
64                         memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
65                         buf += 41;
66                 }
67                 *p++ = NULL;
68                 execvp("git-rev-list", argv);
69                 die("git-upload-pack: unable to exec git-rev-list");
70         }
71         dup2(fd[0], 0);
72         close(fd[0]);
73         close(fd[1]);
74         execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
75         die("git-upload-pack: unable to exec git-pack-objects");
76 }
77
78 static int got_sha1(char *hex, unsigned char *sha1)
79 {
80         int nr;
81         if (get_sha1_hex(hex, sha1))
82                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
83         if (!has_sha1_file(sha1))
84                 return 0;
85         nr = nr_has;
86         if (nr < MAX_HAS) {
87                 memcpy(has_sha1[nr], sha1, 20);
88                 nr_has = nr+1;
89         }
90         return 1;
91 }
92
93 static int get_common_commits(void)
94 {
95         static char line[1000];
96         unsigned char sha1[20];
97         int len;
98
99         for(;;) {
100                 len = packet_read_line(0, line, sizeof(line));
101
102                 if (!len) {
103                         packet_write(1, "NAK\n");
104                         continue;
105                 }
106                 len = strip(line, len);
107                 if (!strncmp(line, "have ", 5)) {
108                         if (got_sha1(line+5, sha1)) {
109                                 packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
110                                 break;
111                         }
112                         continue;
113                 }
114                 if (!strcmp(line, "done")) {
115                         packet_write(1, "NAK\n");
116                         return -1;
117                 }
118                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
119         }
120
121         for (;;) {
122                 len = packet_read_line(0, line, sizeof(line));
123                 if (!len)
124                         continue;
125                 len = strip(line, len);
126                 if (!strncmp(line, "have ", 5)) {
127                         got_sha1(line+5, sha1);
128                         continue;
129                 }
130                 if (!strcmp(line, "done"))
131                         break;
132                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
133         }
134         return 0;
135 }
136
137 static int receive_needs(void)
138 {
139         static char line[1000];
140         int len, needs;
141
142         needs = 0;
143         for (;;) {
144                 unsigned char dummy[20], *sha1_buf;
145                 len = packet_read_line(0, line, sizeof(line));
146                 if (!len)
147                         return needs;
148
149                 sha1_buf = dummy;
150                 if (needs == MAX_NEEDS) {
151                         fprintf(stderr,
152                                 "warning: supporting only a max of %d requests. "
153                                 "sending everything instead.\n",
154                                 MAX_NEEDS);
155                 }
156                 else if (needs < MAX_NEEDS)
157                         sha1_buf = needs_sha1[needs];
158
159                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
160                         die("git-upload-pack: protocol error, "
161                             "expected to get sha, not '%s'", line);
162                 needs++;
163         }
164 }
165
166 static int send_ref(const char *refname, const unsigned char *sha1)
167 {
168         packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
169         return 0;
170 }
171
172 static int upload_pack(void)
173 {
174         head_ref(send_ref);
175         for_each_ref(send_ref);
176         packet_flush(1);
177         nr_needs = receive_needs();
178         if (!nr_needs)
179                 return 0;
180         get_common_commits();
181         create_pack_file();
182         return 0;
183 }
184
185 int main(int argc, char **argv)
186 {
187         const char *dir;
188         if (argc != 2)
189                 usage(upload_pack_usage);
190         dir = argv[1];
191
192         /* chdir to the directory. If that fails, try appending ".git" */
193         if (chdir(dir) < 0) {
194                 if (chdir(mkpath("%s.git", dir)) < 0)
195                         die("git-upload-pack unable to chdir to %s", dir);
196         }
197         chdir(".git");
198         if (access("objects", X_OK) || access("refs", X_OK))
199                 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
200         putenv("GIT_DIR=.");
201         upload_pack();
202         return 0;
203 }