[PATCH] Fix local pull that uses packs.
[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 = nr_has + nr_needs + 5;
34                 char **argv = xmalloc(args * sizeof(char *));
35                 char *buf = xmalloc(args * 45);
36                 char **p = argv;
37
38                 dup2(fd[1], 1);
39                 close(0);
40                 close(fd[0]);
41                 close(fd[1]);
42                 *p++ = "git-rev-list";
43                 *p++ = "--objects";
44                 for (i = 0; i < nr_needs; i++) {
45                         *p++ = buf;
46                         memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
47                         buf += 41;
48                 }
49                 for (i = 0; i < nr_has; i++) {
50                         *p++ = buf;
51                         *buf++ = '^';
52                         memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
53                         buf += 41;
54                 }
55                 *p++ = NULL;
56                 execvp("git-rev-list", argv);
57                 die("git-upload-pack: unable to exec git-rev-list");
58         }
59         dup2(fd[0], 0);
60         close(fd[0]);
61         close(fd[1]);
62         execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
63         die("git-upload-pack: unable to exec git-pack-objects");
64 }
65
66 static int got_sha1(char *hex, unsigned char *sha1)
67 {
68         int nr;
69         if (get_sha1_hex(hex, sha1))
70                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
71         if (!has_sha1_file(sha1))
72                 return 0;
73         nr = nr_has;
74         if (nr < MAX_HAS) {
75                 memcpy(has_sha1[nr], sha1, 20);
76                 nr_has = nr+1;
77         }
78         return 1;
79 }
80
81 static int get_common_commits(void)
82 {
83         static char line[1000];
84         unsigned char sha1[20];
85         int len;
86
87         for(;;) {
88                 len = packet_read_line(0, line, sizeof(line));
89
90                 if (!len) {
91                         packet_write(1, "NAK\n");
92                         continue;
93                 }
94                 len = strip(line, len);
95                 if (!strncmp(line, "have ", 5)) {
96                         if (got_sha1(line+5, sha1)) {
97                                 packet_write(1, "ACK %s\n", sha1_to_hex(sha1));
98                                 break;
99                         }
100                         continue;
101                 }
102                 if (!strcmp(line, "done")) {
103                         packet_write(1, "NAK\n");
104                         return -1;
105                 }
106                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
107         }
108
109         for (;;) {
110                 len = packet_read_line(0, line, sizeof(line));
111                 if (!len)
112                         continue;
113                 len = strip(line, len);
114                 if (!strncmp(line, "have ", 5)) {
115                         got_sha1(line+5, sha1);
116                         continue;
117                 }
118                 if (!strcmp(line, "done"))
119                         break;
120                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
121         }
122         return 0;
123 }
124
125 static int receive_needs(void)
126 {
127         static char line[1000];
128         int len, needs;
129
130         needs = 0;
131         for (;;) {
132                 len = packet_read_line(0, line, sizeof(line));
133                 if (!len)
134                         return needs;
135
136                 /*
137                  * This is purely theoretical right now: git-fetch-pack only
138                  * ever asks for a single HEAD
139                  */
140                 if (needs >= MAX_NEEDS)
141                         die("I'm only doing a max of %d requests", MAX_NEEDS);
142                 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, needs_sha1[needs]))
143                         die("git-upload-pack: protocol error, expected to get sha, not '%s'", line);
144                 needs++;
145         }
146 }
147
148 static int send_ref(const char *refname, const unsigned char *sha1)
149 {
150         packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
151         return 0;
152 }
153
154 static int upload_pack(void)
155 {
156         head_ref(send_ref);
157         for_each_ref(send_ref);
158         packet_flush(1);
159         nr_needs = receive_needs();
160         if (!nr_needs)
161                 return 0;
162         get_common_commits();
163         create_pack_file();
164         return 0;
165 }
166
167 int main(int argc, char **argv)
168 {
169         const char *dir;
170         if (argc != 2)
171                 usage(upload_pack_usage);
172         dir = argv[1];
173
174         /* chdir to the directory. If that fails, try appending ".git" */
175         if (chdir(dir) < 0) {
176                 if (chdir(mkpath("%s.git", dir)) < 0)
177                         die("git-upload-pack unable to chdir to %s", dir);
178         }
179         chdir(".git");
180         if (access("objects", X_OK) || access("refs", X_OK))
181                 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
182         setenv("GIT_DIR", ".", 1);
183         upload_pack();
184         return 0;
185 }