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[git.git] / ssh-fetch.c
1 #ifndef COUNTERPART_ENV_NAME
2 #define COUNTERPART_ENV_NAME "GIT_SSH_UPLOAD"
3 #endif
4 #ifndef COUNTERPART_PROGRAM_NAME
5 #define COUNTERPART_PROGRAM_NAME "git-ssh-upload"
6 #endif
7 #ifndef MY_PROGRAM_NAME
8 #define MY_PROGRAM_NAME "git-ssh-fetch"
9 #endif
10
11 #include "cache.h"
12 #include "commit.h"
13 #include "rsh.h"
14 #include "fetch.h"
15 #include "refs.h"
16
17 static int fd_in;
18 static int fd_out;
19
20 static unsigned char remote_version = 0;
21 static unsigned char local_version = 1;
22
23 static ssize_t force_write(int fd, void *buffer, size_t length)
24 {
25         ssize_t ret = 0;
26         while (ret < length) {
27                 ssize_t size = write(fd, buffer + ret, length - ret);
28                 if (size < 0) {
29                         return size;
30                 }
31                 if (size == 0) {
32                         return ret;
33                 }
34                 ret += size;
35         }
36         return ret;
37 }
38
39 static int prefetches = 0;
40
41 static struct object_list *in_transit = NULL;
42 static struct object_list **end_of_transit = &in_transit;
43
44 void prefetch(unsigned char *sha1)
45 {
46         char type = 'o';
47         struct object_list *node;
48         if (prefetches > 100) {
49                 fetch(in_transit->item->sha1);
50         }
51         node = xmalloc(sizeof(struct object_list));
52         node->next = NULL;
53         node->item = lookup_unknown_object(sha1);
54         *end_of_transit = node;
55         end_of_transit = &node->next;
56         force_write(fd_out, &type, 1);
57         force_write(fd_out, sha1, 20);
58         prefetches++;
59 }
60
61 static char conn_buf[4096];
62 static size_t conn_buf_posn = 0;
63
64 int fetch(unsigned char *sha1)
65 {
66         int ret;
67         signed char remote;
68         struct object_list *temp;
69
70         if (memcmp(sha1, in_transit->item->sha1, 20)) {
71                 // we must have already fetched it to clean the queue
72                 return has_sha1_file(sha1) ? 0 : -1;
73         }
74         prefetches--;
75         temp = in_transit;
76         in_transit = in_transit->next;
77         if (!in_transit)
78                 end_of_transit = &in_transit;
79         free(temp);
80
81         if (conn_buf_posn) {
82                 remote = conn_buf[0];
83                 memmove(conn_buf, conn_buf + 1, --conn_buf_posn);
84         } else {
85                 if (read(fd_in, &remote, 1) < 1)
86                         return -1;
87         }
88         //fprintf(stderr, "Got %d\n", remote);
89         if (remote < 0)
90                 return remote;
91         ret = write_sha1_from_fd(sha1, fd_in, conn_buf, 4096, &conn_buf_posn);
92         if (!ret)
93                 pull_say("got %s\n", sha1_to_hex(sha1));
94         return ret;
95 }
96
97 static int get_version(void)
98 {
99         char type = 'v';
100         write(fd_out, &type, 1);
101         write(fd_out, &local_version, 1);
102         if (read(fd_in, &remote_version, 1) < 1) {
103                 return error("Couldn't read version from remote end");
104         }
105         return 0;
106 }
107
108 int fetch_ref(char *ref, unsigned char *sha1)
109 {
110         signed char remote;
111         char type = 'r';
112         write(fd_out, &type, 1);
113         write(fd_out, ref, strlen(ref) + 1);
114         read(fd_in, &remote, 1);
115         if (remote < 0)
116                 return remote;
117         read(fd_in, sha1, 20);
118         return 0;
119 }
120
121 static const char ssh_fetch_usage[] =
122   MY_PROGRAM_NAME
123   " [-c] [-t] [-a] [-v] [-d] [--recover] [-w ref] commit-id url";
124 int main(int argc, char **argv)
125 {
126         char *commit_id;
127         char *url;
128         int arg = 1;
129         const char *prog;
130
131         prog = getenv("GIT_SSH_PUSH");
132         if (!prog) prog = "git-ssh-upload";
133
134         while (arg < argc && argv[arg][0] == '-') {
135                 if (argv[arg][1] == 't') {
136                         get_tree = 1;
137                 } else if (argv[arg][1] == 'c') {
138                         get_history = 1;
139                 } else if (argv[arg][1] == 'a') {
140                         get_all = 1;
141                         get_tree = 1;
142                         get_history = 1;
143                 } else if (argv[arg][1] == 'v') {
144                         get_verbosely = 1;
145                 } else if (argv[arg][1] == 'w') {
146                         write_ref = argv[arg + 1];
147                         arg++;
148                 } else if (!strcmp(argv[arg], "--recover")) {
149                         get_recover = 1;
150                 }
151                 arg++;
152         }
153         if (argc < arg + 2) {
154                 usage(ssh_fetch_usage);
155                 return 1;
156         }
157         commit_id = argv[arg];
158         url = argv[arg + 1];
159
160         if (setup_connection(&fd_in, &fd_out, prog, url, arg, argv + 1))
161                 return 1;
162
163         if (get_version())
164                 return 1;
165
166         if (pull(commit_id))
167                 return 1;
168
169         return 0;
170 }