Add "git_path()" and "head_ref()" helper functions.
[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
LT
5
6static const char fetch_pack_usage[] = "git-fetch-pack [host:]directory [heads]* < mycommitlist";
7static const char *exec = "git-upload-pack";
8
9static int get_ack(int fd, unsigned char *result_sha1)
10{
11 static char line[1000];
12 int len = packet_read_line(fd, line, sizeof(line));
13
14 if (!len)
15 die("git-fetch-pack: expected ACK/NAK, got EOF");
16 if (line[len-1] == '\n')
17 line[--len] = 0;
18 if (!strcmp(line, "NAK"))
19 return 0;
20 if (!strncmp(line, "ACK ", 3)) {
21 if (!get_sha1_hex(line+4, result_sha1))
22 return 1;
23 }
24 die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
25}
26
fb9040cc 27static int find_common(int fd[2], unsigned char *result_sha1, unsigned char *remote)
def88e9a
LT
28{
29 static char line[1000];
75bfc6c2
LT
30 int count = 0, flushes = 0, retval;
31 FILE *revs;
def88e9a 32
75bfc6c2
LT
33 revs = popen("git-rev-list $(git-rev-parse --all)", "r");
34 if (!revs)
35 die("unable to run 'git-rev-list'");
fb9040cc
LT
36 packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
37 packet_flush(fd[1]);
75bfc6c2
LT
38 flushes = 1;
39 retval = -1;
40 while (fgets(line, sizeof(line), revs) != NULL) {
def88e9a
LT
41 unsigned char sha1[20];
42 if (get_sha1_hex(line, sha1))
43 die("git-fetch-pack: expected object name, got crud");
44 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
45 if (!(31 & ++count)) {
46 packet_flush(fd[1]);
47 flushes++;
48
49 /*
50 * We keep one window "ahead" of the other side, and
51 * will wait for an ACK only on the next one
52 */
53 if (count == 32)
54 continue;
75bfc6c2
LT
55 if (get_ack(fd[0], result_sha1)) {
56 flushes = 0;
57 retval = 0;
58 break;
59 }
def88e9a
LT
60 flushes--;
61 }
62 }
75bfc6c2
LT
63 pclose(revs);
64 packet_write(fd[1], "done\n");
def88e9a
LT
65 while (flushes) {
66 flushes--;
67 if (get_ack(fd[0], result_sha1))
68 return 0;
69 }
75bfc6c2 70 return retval;
def88e9a
LT
71}
72
fb9040cc
LT
73static int get_old_sha1(const char *refname, unsigned char *sha1)
74{
fb9040cc
LT
75 int fd, ret;
76
723c31fe 77 fd = open(git_path("%s", refname), O_RDONLY);
fb9040cc
LT
78 ret = -1;
79 if (fd >= 0) {
80 char buffer[60];
81 if (read(fd, buffer, sizeof(buffer)) >= 40)
82 ret = get_sha1_hex(buffer, sha1);
83 close(fd);
84 }
85 return ret;
86}
87
88static int check_ref(const char *refname, const unsigned char *sha1)
def88e9a 89{
fb9040cc
LT
90 unsigned char mysha1[20];
91 char oldhex[41];
92
93 if (get_old_sha1(refname, mysha1) < 0)
94 memset(mysha1, 0, 20);
95
96 if (!memcmp(sha1, mysha1, 20)) {
75bfc6c2 97 fprintf(stderr, "%s: unchanged\n", refname);
fb9040cc
LT
98 return 0;
99 }
100
101 memcpy(oldhex, sha1_to_hex(mysha1), 41);
75bfc6c2 102 fprintf(stderr, "%s: %s (%s)\n", refname, sha1_to_hex(sha1), oldhex);
fb9040cc
LT
103 return 1;
104}
105
106static int get_remote_heads(int fd, int nr_match, char **match, unsigned char *result)
107{
108 int count = 0;
109
def88e9a
LT
110 for (;;) {
111 static char line[1000];
112 unsigned char sha1[20];
113 char *refname;
114 int len;
115
116 len = packet_read_line(fd, line, sizeof(line));
117 if (!len)
118 break;
119 if (line[len-1] == '\n')
120 line[--len] = 0;
121 if (len < 42 || get_sha1_hex(line, sha1))
122 die("git-fetch-pack: protocol error - expected ref descriptor, got '%sä'", line);
123 refname = line+41;
124 if (nr_match && !path_match(refname, nr_match, match))
125 continue;
fb9040cc
LT
126 if (check_ref(refname, sha1)) {
127 count++;
128 memcpy(result, sha1, 20);
129 }
def88e9a 130 }
fb9040cc 131 return count;
def88e9a
LT
132}
133
134static int fetch_pack(int fd[2], int nr_match, char **match)
135{
fb9040cc 136 unsigned char sha1[20], remote[20];
75bfc6c2
LT
137 int heads, status;
138 pid_t pid;
def88e9a 139
fb9040cc
LT
140 heads = get_remote_heads(fd[0], nr_match, match, remote);
141 if (heads != 1) {
142 packet_flush(fd[1]);
143 die(heads ? "multiple remote heads" : "no matching remote head");
144 }
145 if (find_common(fd, sha1, remote) < 0)
def88e9a 146 die("git-fetch-pack: no common commits");
75bfc6c2
LT
147 pid = fork();
148 if (pid < 0)
149 die("git-fetch-pack: unable to fork off git-unpack-objects");
150 if (!pid) {
151 close(fd[1]);
152 dup2(fd[0], 0);
153 close(fd[0]);
154 execlp("git-unpack-objects", "git-unpack-objects", NULL);
155 die("git-unpack-objects exec failed");
156 }
fb9040cc 157 close(fd[0]);
75bfc6c2
LT
158 close(fd[1]);
159 while (waitpid(pid, &status, 0) < 0) {
160 if (errno != EINTR)
161 die("waiting for git-unpack-objects: %s", strerror(errno));
162 }
163 if (WIFEXITED(status)) {
164 int code = WEXITSTATUS(status);
165 if (code)
166 die("git-unpack-objects died with error code %d", code);
167 puts(sha1_to_hex(remote));
168 return 0;
169 }
170 if (WIFSIGNALED(status)) {
171 int sig = WTERMSIG(status);
172 die("git-unpack-objects died of signal %d", sig);
173 }
174 die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
def88e9a
LT
175}
176
177int main(int argc, char **argv)
178{
179 int i, ret, nr_heads;
180 char *dest = NULL, **heads;
181 int fd[2];
182 pid_t pid;
183
184 nr_heads = 0;
185 heads = NULL;
186 for (i = 1; i < argc; i++) {
187 char *arg = argv[i];
188
189 if (*arg == '-') {
190 /* Arguments go here */
191 usage(fetch_pack_usage);
192 }
193 dest = arg;
194 heads = argv + i + 1;
195 nr_heads = argc - i - 1;
196 break;
197 }
198 if (!dest)
199 usage(fetch_pack_usage);
200 pid = git_connect(fd, dest, exec);
201 if (pid < 0)
202 return 1;
203 ret = fetch_pack(fd, nr_heads, heads);
204 close(fd[0]);
205 close(fd[1]);
206 finish_connect(pid);
207 return ret;
208}