Update unpack-objects usage and documentation.
[git/git.git] / fetch-pack.c
CommitLineData
def88e9a 1#include "cache.h"
fb9040cc 2#include "refs.h"
def88e9a 3#include "pkt-line.h"
75bfc6c2 4#include <sys/wait.h>
def88e9a 5
8b3d9dc0
JH
6static int quiet;
7static const char fetch_pack_usage[] = "git-fetch-pack [-q] [--exec=upload-pack] [host:]directory [heads]* < mycommitlist";
def88e9a
LT
8static const char *exec = "git-upload-pack";
9
fb9040cc 10static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *remote)
def88e9a
LT
11{
12 static char line[1000];
75bfc6c2
LT
13 int count = 0, flushes = 0, retval;
14 FILE *revs;
def88e9a 15
75bfc6c2
LT
16 revs = popen("git-rev-list $(git-rev-parse --all)", "r");
17 if (!revs)
18 die("unable to run 'git-rev-list'");
fb9040cc
LT
19 packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
20 packet_flush(fd[1]);
75bfc6c2
LT
21 flushes = 1;
22 retval = -1;
23 while (fgets(line, sizeof(line), revs) != NULL) {
def88e9a
LT
24 unsigned char sha1[20];
25 if (get_sha1_hex(line, sha1))
26 die("git-fetch-pack: expected object name, got crud");
27 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
28 if (!(31 & ++count)) {
29 packet_flush(fd[1]);
30 flushes++;
31
32 /*
33 * We keep one window "ahead" of the other side, and
34 * will wait for an ACK only on the next one
35 */
36 if (count == 32)
37 continue;
75bfc6c2
LT
38 if (get_ack(fd[0], result_sha1)) {
39 flushes = 0;
40 retval = 0;
41 break;
42 }
def88e9a
LT
43 flushes--;
44 }
45 }
75bfc6c2
LT
46 pclose(revs);
47 packet_write(fd[1], "done\n");
def88e9a
LT
48 while (flushes) {
49 flushes--;
50 if (get_ack(fd[0], result_sha1))
51 return 0;
52 }
75bfc6c2 53 return retval;
def88e9a
LT
54}
55
d1c133f5
LT
56/*
57 * Eventually we'll want to be able to fetch multiple heads.
58 *
59 * Right now we'll just require a single match.
60 */
def88e9a
LT
61static int fetch_pack(int fd[2], int nr_match, char **match)
62{
d1c133f5
LT
63 struct ref *ref;
64 unsigned char sha1[20];
65 int status;
75bfc6c2 66 pid_t pid;
def88e9a 67
d1c133f5
LT
68 get_remote_heads(fd[0], &ref, nr_match, match);
69 if (!ref) {
70 packet_flush(fd[1]);
71 die("no matching remote head");
72 }
73 if (ref->next) {
fb9040cc 74 packet_flush(fd[1]);
d1c133f5 75 die("multiple remote heads");
fb9040cc 76 }
d1c133f5 77 if (find_common(fd, sha1, ref->old_sha1) < 0)
def88e9a 78 die("git-fetch-pack: no common commits");
75bfc6c2
LT
79 pid = fork();
80 if (pid < 0)
81 die("git-fetch-pack: unable to fork off git-unpack-objects");
82 if (!pid) {
75bfc6c2
LT
83 dup2(fd[0], 0);
84 close(fd[0]);
85c414b5 85 close(fd[1]);
8b3d9dc0
JH
86 execlp("git-unpack-objects", "git-unpack-objects",
87 quiet ? "-q" : NULL, NULL);
75bfc6c2
LT
88 die("git-unpack-objects exec failed");
89 }
fb9040cc 90 close(fd[0]);
75bfc6c2
LT
91 close(fd[1]);
92 while (waitpid(pid, &status, 0) < 0) {
93 if (errno != EINTR)
94 die("waiting for git-unpack-objects: %s", strerror(errno));
95 }
96 if (WIFEXITED(status)) {
97 int code = WEXITSTATUS(status);
98 if (code)
99 die("git-unpack-objects died with error code %d", code);
d1c133f5 100 puts(sha1_to_hex(ref->old_sha1));
75bfc6c2
LT
101 return 0;
102 }
103 if (WIFSIGNALED(status)) {
104 int sig = WTERMSIG(status);
105 die("git-unpack-objects died of signal %d", sig);
106 }
107 die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
def88e9a
LT
108}
109
110int main(int argc, char **argv)
111{
112 int i, ret, nr_heads;
113 char *dest = NULL, **heads;
114 int fd[2];
115 pid_t pid;
116
117 nr_heads = 0;
118 heads = NULL;
119 for (i = 1; i < argc; i++) {
120 char *arg = argv[i];
121
122 if (*arg == '-') {
8b3d9dc0
JH
123 if (!strncmp("--exec=", arg, 7)) {
124 exec = arg + 7;
125 continue;
126 }
def88e9a
LT
127 usage(fetch_pack_usage);
128 }
129 dest = arg;
130 heads = argv + i + 1;
131 nr_heads = argc - i - 1;
132 break;
133 }
134 if (!dest)
135 usage(fetch_pack_usage);
136 pid = git_connect(fd, dest, exec);
137 if (pid < 0)
138 return 1;
139 ret = fetch_pack(fd, nr_heads, heads);
140 close(fd[0]);
141 close(fd[1]);
142 finish_connect(pid);
143 return ret;
144}