git-fetch-pack: avoid unnecessary zero packing
[git/jrn.git] / fetch-pack.c
blob459736909cb3b16348b5dab893461e41b98f89aa
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include <sys/wait.h>
6 static int quiet;
7 static int verbose;
8 static const char fetch_pack_usage[] =
9 "git-fetch-pack [-q] [-v] [--exec=upload-pack] [host:]directory <refs>...";
10 static const char *exec = "git-upload-pack";
12 static int find_common(int fd[2], unsigned char *result_sha1,
13 struct ref *refs)
15 int fetching;
16 static char line[1000];
17 int count = 0, flushes = 0, retval;
18 FILE *revs;
20 revs = popen("git-rev-list $(git-rev-parse --all)", "r");
21 if (!revs)
22 die("unable to run 'git-rev-list'");
24 fetching = 0;
25 for ( ; refs ; refs = refs->next) {
26 unsigned char *remote = refs->old_sha1;
27 unsigned char *local = refs->new_sha1;
29 if (!memcmp(remote, local, 20))
30 continue;
31 packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
32 fetching++;
34 packet_flush(fd[1]);
35 if (!fetching)
36 return 1;
37 flushes = 1;
38 retval = -1;
39 while (fgets(line, sizeof(line), revs) != NULL) {
40 unsigned char sha1[20];
41 if (get_sha1_hex(line, sha1))
42 die("git-fetch-pack: expected object name, got crud");
43 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
44 if (verbose)
45 fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
46 if (!(31 & ++count)) {
47 packet_flush(fd[1]);
48 flushes++;
51 * We keep one window "ahead" of the other side, and
52 * will wait for an ACK only on the next one
54 if (count == 32)
55 continue;
56 if (get_ack(fd[0], result_sha1)) {
57 flushes = 0;
58 retval = 0;
59 if (verbose)
60 fprintf(stderr, "got ack\n");
61 break;
63 flushes--;
66 pclose(revs);
67 packet_write(fd[1], "done\n");
68 if (verbose)
69 fprintf(stderr, "done\n");
70 while (flushes) {
71 flushes--;
72 if (get_ack(fd[0], result_sha1)) {
73 if (verbose)
74 fprintf(stderr, "got ack\n");
75 return 0;
78 return retval;
81 static int everything_local(struct ref *refs)
83 int retval;
85 for (retval = 1; refs ; refs = refs->next) {
86 const unsigned char *remote = refs->old_sha1;
87 unsigned char local[20];
89 if (read_ref(git_path("%s", refs->name), local) < 0 ||
90 memcmp(remote, local, 20)) {
91 retval = 0;
92 if (!verbose)
93 continue;
94 fprintf(stderr,
95 "want %s (%s)\n", sha1_to_hex(remote),
96 refs->name);
97 continue;
100 memcpy(refs->new_sha1, local, 20);
101 if (!verbose)
102 continue;
103 fprintf(stderr,
104 "already have %s (%s)\n", sha1_to_hex(remote),
105 refs->name);
107 return retval;
110 static int fetch_pack(int fd[2], int nr_match, char **match)
112 struct ref *ref;
113 unsigned char sha1[20];
114 int status;
115 pid_t pid;
117 get_remote_heads(fd[0], &ref, nr_match, match, 1);
118 if (!ref) {
119 packet_flush(fd[1]);
120 die("no matching remote head");
122 if (everything_local(ref)) {
123 packet_flush(fd[1]);
124 goto all_done;
126 if (find_common(fd, sha1, ref) < 0)
127 fprintf(stderr, "warning: no common commits\n");
128 pid = fork();
129 if (pid < 0)
130 die("git-fetch-pack: unable to fork off git-unpack-objects");
131 if (!pid) {
132 dup2(fd[0], 0);
133 close(fd[0]);
134 close(fd[1]);
135 execlp("git-unpack-objects", "git-unpack-objects",
136 quiet ? "-q" : NULL, NULL);
137 die("git-unpack-objects exec failed");
139 close(fd[0]);
140 close(fd[1]);
141 while (waitpid(pid, &status, 0) < 0) {
142 if (errno != EINTR)
143 die("waiting for git-unpack-objects: %s", strerror(errno));
145 if (WIFEXITED(status)) {
146 int code = WEXITSTATUS(status);
147 if (code)
148 die("git-unpack-objects died with error code %d", code);
149 all_done:
150 while (ref) {
151 printf("%s %s\n",
152 sha1_to_hex(ref->old_sha1), ref->name);
153 ref = ref->next;
155 return 0;
157 if (WIFSIGNALED(status)) {
158 int sig = WTERMSIG(status);
159 die("git-unpack-objects died of signal %d", sig);
161 die("Sherlock Holmes! git-unpack-objects died of unnatural causes %d!", status);
164 int main(int argc, char **argv)
166 int i, ret, nr_heads;
167 char *dest = NULL, **heads;
168 int fd[2];
169 pid_t pid;
171 nr_heads = 0;
172 heads = NULL;
173 for (i = 1; i < argc; i++) {
174 char *arg = argv[i];
176 if (*arg == '-') {
177 if (!strncmp("--exec=", arg, 7)) {
178 exec = arg + 7;
179 continue;
181 if (!strcmp("-q", arg)) {
182 quiet = 1;
183 continue;
185 if (!strcmp("-v", arg)) {
186 verbose = 1;
187 continue;
189 usage(fetch_pack_usage);
191 dest = arg;
192 heads = argv + i + 1;
193 nr_heads = argc - i - 1;
194 break;
196 if (!dest)
197 usage(fetch_pack_usage);
198 pid = git_connect(fd, dest, exec);
199 if (pid < 0)
200 return 1;
201 ret = fetch_pack(fd, nr_heads, heads);
202 close(fd[0]);
203 close(fd[1]);
204 finish_connect(pid);
205 return ret;