git-upload-pack: Support sending multiple ACK messages
[git/git.git] / upload-pack.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "pkt-line.h"
4 #include "tag.h"
5 #include "object.h"
6 #include "commit.h"
7
8 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
9
10 #define THEY_HAVE (1U << 0)
11 #define MAX_HAS 256
12 #define MAX_NEEDS 256
13 static int nr_has = 0, nr_needs = 0, multi_ack = 0;
14 static unsigned char has_sha1[MAX_HAS][20];
15 static unsigned char needs_sha1[MAX_NEEDS][20];
16 static unsigned int timeout = 0;
17
18 static void reset_timeout(void)
19 {
20 alarm(timeout);
21 }
22
23 static int strip(char *line, int len)
24 {
25 if (len && line[len-1] == '\n')
26 line[--len] = 0;
27 return len;
28 }
29
30 static void create_pack_file(void)
31 {
32 int fd[2];
33 pid_t pid;
34
35 if (pipe(fd) < 0)
36 die("git-upload-pack: unable to create pipe");
37 pid = fork();
38 if (pid < 0)
39 die("git-upload-pack: unable to fork git-rev-list");
40
41 if (!pid) {
42 int i;
43 int args;
44 char **argv;
45 char *buf;
46 char **p;
47
48 if (MAX_NEEDS <= nr_needs)
49 args = nr_has + 10;
50 else
51 args = nr_has + nr_needs + 5;
52 argv = xmalloc(args * sizeof(char *));
53 buf = xmalloc(args * 45);
54 p = argv;
55
56 dup2(fd[1], 1);
57 close(0);
58 close(fd[0]);
59 close(fd[1]);
60 *p++ = "git-rev-list";
61 *p++ = "--objects";
62 if (MAX_NEEDS <= nr_needs)
63 *p++ = "--all";
64 else {
65 for (i = 0; i < nr_needs; i++) {
66 *p++ = buf;
67 memcpy(buf, sha1_to_hex(needs_sha1[i]), 41);
68 buf += 41;
69 }
70 }
71 for (i = 0; i < nr_has; i++) {
72 *p++ = buf;
73 *buf++ = '^';
74 memcpy(buf, sha1_to_hex(has_sha1[i]), 41);
75 buf += 41;
76 }
77 *p++ = NULL;
78 execvp("git-rev-list", argv);
79 die("git-upload-pack: unable to exec git-rev-list");
80 }
81 dup2(fd[0], 0);
82 close(fd[0]);
83 close(fd[1]);
84 execlp("git-pack-objects", "git-pack-objects", "--stdout", NULL);
85 die("git-upload-pack: unable to exec git-pack-objects");
86 }
87
88 static int got_sha1(char *hex, unsigned char *sha1)
89 {
90 if (get_sha1_hex(hex, sha1))
91 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
92 if (!has_sha1_file(sha1))
93 return 0;
94 if (nr_has < MAX_HAS) {
95 struct object *o = lookup_object(sha1);
96 if (!o || (!o->parsed && !parse_object(sha1)))
97 die("oops (%s)", sha1_to_hex(sha1));
98 if (o->type == commit_type) {
99 struct commit_list *parents;
100 if (o->flags & THEY_HAVE)
101 return 0;
102 o->flags |= THEY_HAVE;
103 for (parents = ((struct commit*)o)->parents;
104 parents;
105 parents = parents->next)
106 parents->item->object.flags |= THEY_HAVE;
107 }
108 memcpy(has_sha1[nr_has++], sha1, 20);
109 }
110 return 1;
111 }
112
113 static int get_common_commits(void)
114 {
115 static char line[1000];
116 unsigned char sha1[20];
117 int len;
118
119 track_object_refs = 0;
120 save_commit_buffer = 0;
121
122 for(;;) {
123 len = packet_read_line(0, line, sizeof(line));
124 reset_timeout();
125
126 if (!len) {
127 if (multi_ack || nr_has == 0)
128 packet_write(1, "NAK\n");
129 continue;
130 }
131 len = strip(line, len);
132 if (!strncmp(line, "have ", 5)) {
133 if (got_sha1(line+5, sha1) &&
134 (multi_ack || nr_has == 1))
135 packet_write(1, "ACK %s%s\n",
136 sha1_to_hex(sha1),
137 multi_ack && nr_has < MAX_HAS ?
138 " continue" : "");
139 continue;
140 }
141 if (!strcmp(line, "done")) {
142 if (nr_has > 0)
143 return 0;
144 packet_write(1, "NAK\n");
145 return -1;
146 }
147 die("git-upload-pack: expected SHA1 list, got '%s'", line);
148 }
149 }
150
151 static int receive_needs(void)
152 {
153 static char line[1000];
154 int len, needs;
155
156 needs = 0;
157 for (;;) {
158 unsigned char dummy[20], *sha1_buf;
159 len = packet_read_line(0, line, sizeof(line));
160 reset_timeout();
161 if (!len)
162 return needs;
163
164 sha1_buf = dummy;
165 if (needs == MAX_NEEDS) {
166 fprintf(stderr,
167 "warning: supporting only a max of %d requests. "
168 "sending everything instead.\n",
169 MAX_NEEDS);
170 }
171 else if (needs < MAX_NEEDS)
172 sha1_buf = needs_sha1[needs];
173
174 if (strncmp("want ", line, 5) || get_sha1_hex(line+5, sha1_buf))
175 die("git-upload-pack: protocol error, "
176 "expected to get sha, not '%s'", line);
177
178 if (strstr(line+45, "multi_ack"))
179 multi_ack = 1;
180
181 needs++;
182 }
183 }
184
185 static int send_ref(const char *refname, const unsigned char *sha1)
186 {
187 struct object *o = parse_object(sha1);
188
189 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
190 if (o->type == tag_type) {
191 o = deref_tag(o);
192 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
193 }
194 return 0;
195 }
196
197 static int upload_pack(void)
198 {
199 reset_timeout();
200 head_ref(send_ref);
201 for_each_ref(send_ref);
202 packet_flush(1);
203 nr_needs = receive_needs();
204 if (!nr_needs)
205 return 0;
206 get_common_commits();
207 create_pack_file();
208 return 0;
209 }
210
211 int main(int argc, char **argv)
212 {
213 const char *dir;
214 int i;
215 int strict = 0;
216
217 for (i = 1; i < argc; i++) {
218 char *arg = argv[i];
219
220 if (arg[0] != '-')
221 break;
222 if (!strcmp(arg, "--strict")) {
223 strict = 1;
224 continue;
225 }
226 if (!strncmp(arg, "--timeout=", 10)) {
227 timeout = atoi(arg+10);
228 continue;
229 }
230 if (!strcmp(arg, "--")) {
231 i++;
232 break;
233 }
234 }
235
236 if (i != argc-1)
237 usage(upload_pack_usage);
238 dir = argv[i];
239
240 /* chdir to the directory. If that fails, try appending ".git" */
241 if (chdir(dir) < 0) {
242 if (strict || chdir(mkpath("%s.git", dir)) < 0)
243 die("git-upload-pack unable to chdir to %s", dir);
244 }
245 if (!strict)
246 chdir(".git");
247
248 if (access("objects", X_OK) || access("refs", X_OK))
249 die("git-upload-pack: %s doesn't seem to be a git archive", dir);
250
251 putenv("GIT_DIR=.");
252 upload_pack();
253 return 0;
254 }