aboutsummaryrefslogtreecommitdiff
path: root/ssh-fetch.c
blob: 72965d678ae4e4b2b2fc64e8979d8a9e1d3d81d0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
#ifndef COUNTERPART_ENV_NAME
#define COUNTERPART_ENV_NAME "GIT_SSH_UPLOAD"
#endif
#ifndef COUNTERPART_PROGRAM_NAME
#define COUNTERPART_PROGRAM_NAME "git-ssh-upload"
#endif
#ifndef MY_PROGRAM_NAME
#define MY_PROGRAM_NAME "git-ssh-fetch"
#endif

#include "cache.h"
#include "commit.h"
#include "rsh.h"
#include "fetch.h"
#include "refs.h"

static int fd_in;
static int fd_out;

static unsigned char remote_version;
static unsigned char local_version = 1;

static ssize_t force_write(int fd, void *buffer, size_t length)
{
	ssize_t ret = 0;
	while (ret < length) {
		ssize_t size = write(fd, (char *) buffer + ret, length - ret);
		if (size < 0) {
			return size;
		}
		if (size == 0) {
			return ret;
		}
		ret += size;
	}
	return ret;
}

static int prefetches;

static struct object_list *in_transit;
static struct object_list **end_of_transit = &in_transit;

void prefetch(unsigned char *sha1)
{
	char type = 'o';
	struct object_list *node;
	if (prefetches > 100) {
		fetch(in_transit->item->sha1);
	}
	node = xmalloc(sizeof(struct object_list));
	node->next = NULL;
	node->item = lookup_unknown_object(sha1);
	*end_of_transit = node;
	end_of_transit = &node->next;
	force_write(fd_out, &type, 1);
	force_write(fd_out, sha1, 20);
	prefetches++;
}

static char conn_buf[4096];
static size_t conn_buf_posn;

int fetch(unsigned char *sha1)
{
	int ret;
	signed char remote;
	struct object_list *temp;

	if (hashcmp(sha1, in_transit->item->sha1)) {
		/* we must have already fetched it to clean the queue */
		return has_sha1_file(sha1) ? 0 : -1;
	}
	prefetches--;
	temp = in_transit;
	in_transit = in_transit->next;
	if (!in_transit)
		end_of_transit = &in_transit;
	free(temp);

	if (conn_buf_posn) {
		remote = conn_buf[0];
		memmove(conn_buf, conn_buf + 1, --conn_buf_posn);
	} else {
		if (xread(fd_in, &remote, 1) < 1)
			return -1;
	}
	/* fprintf(stderr, "Got %d\n", remote); */
	if (remote < 0)
		return remote;
	ret = write_sha1_from_fd(sha1, fd_in, conn_buf, 4096, &conn_buf_posn);
	if (!ret)
		pull_say("got %s\n", sha1_to_hex(sha1));
	return ret;
}

static int get_version(void)
{
	char type = 'v';
	write(fd_out, &type, 1);
	write(fd_out, &local_version, 1);
	if (xread(fd_in, &remote_version, 1) < 1) {
		return error("Couldn't read version from remote end");
	}
	return 0;
}

int fetch_ref(char *ref, unsigned char *sha1)
{
	signed char remote;
	char type = 'r';
	write(fd_out, &type, 1);
	write(fd_out, ref, strlen(ref) + 1);

	if (read_in_full(fd_in, &remote, 1) != 1)
		return -1;
	if (remote < 0)
		return remote;
	if (read_in_full(fd_in, sha1, 20) != 20)
		return -1;
	return 0;
}

static const char ssh_fetch_usage[] =
  MY_PROGRAM_NAME
  " [-c] [-t] [-a] [-v] [--recover] [-w ref] commit-id url";
int main(int argc, char **argv)
{
	const char *write_ref = NULL;
	char *commit_id;
	char *url;
	int arg = 1;
	const char *prog;

	prog = getenv("GIT_SSH_PUSH");
	if (!prog) prog = "git-ssh-upload";

	setup_ident();
	setup_git_directory();
	git_config(git_default_config);

	while (arg < argc && argv[arg][0] == '-') {
		if (argv[arg][1] == 't') {
			get_tree = 1;
		} else if (argv[arg][1] == 'c') {
			get_history = 1;
		} else if (argv[arg][1] == 'a') {
			get_all = 1;
			get_tree = 1;
			get_history = 1;
		} else if (argv[arg][1] == 'v') {
			get_verbosely = 1;
		} else if (argv[arg][1] == 'w') {
			write_ref = argv[arg + 1];
			arg++;
		} else if (!strcmp(argv[arg], "--recover")) {
			get_recover = 1;
		}
		arg++;
	}
	if (argc < arg + 2) {
		usage(ssh_fetch_usage);
		return 1;
	}
	commit_id = argv[arg];
	url = argv[arg + 1];

	if (setup_connection(&fd_in, &fd_out, prog, url, arg, argv + 1))
		return 1;

	if (get_version())
		return 1;

	if (pull(1, &commit_id, &write_ref, url))
		return 1;

	return 0;
}