Short-cut error return path in git-local-pull.
[git.git] / local-pull.c
1 /*
2  * Copyright (C) 2005 Junio C Hamano
3  */
4 #include <fcntl.h>
5 #include <unistd.h>
6 #include <string.h>
7 #include <stdlib.h>
8 #include "cache.h"
9 #include "commit.h"
10 #include <errno.h>
11 #include <stdio.h>
12 #include "pull.h"
13
14 static int use_link = 0;
15 static int use_symlink = 0;
16 static int use_filecopy = 1;
17 static int verbose = 0;
18
19 static char *path;
20
21 static void say(const char *fmt, const char *hex) {
22         if (verbose)
23                 fprintf(stderr, fmt, hex);
24 }
25
26 int fetch(unsigned char *sha1)
27 {
28         static int object_name_start = -1;
29         static char filename[PATH_MAX];
30         char *hex = sha1_to_hex(sha1);
31         const char *dest_filename = sha1_file_name(sha1);
32
33         if (object_name_start < 0) {
34                 strcpy(filename, path); /* e.g. git.git */
35                 strcat(filename, "/objects/");
36                 object_name_start = strlen(filename);
37         }
38         filename[object_name_start+0] = hex[0];
39         filename[object_name_start+1] = hex[1];
40         filename[object_name_start+2] = '/';
41         strcpy(filename + object_name_start + 3, hex + 2);
42         if (use_link) {
43                 if (!link(filename, dest_filename)) {
44                         say("link %s\n", hex);
45                         return 0;
46                 }
47                 /* If we got ENOENT there is no point continuing. */
48                 if (errno == ENOENT) {
49                         fprintf(stderr, "does not exist %s\n", filename);
50                         return -1;
51                 }
52         }
53         if (use_symlink && !symlink(filename, dest_filename)) {
54                 say("symlink %s\n", hex);
55                 return 0;
56         }
57         if (use_filecopy) {
58                 int ifd, ofd, status;
59                 struct stat st;
60                 void *map;
61                 ifd = open(filename, O_RDONLY);
62                 if (ifd < 0 || fstat(ifd, &st) < 0) {
63                         close(ifd);
64                         fprintf(stderr, "cannot open %s\n", filename);
65                         return -1;
66                 }
67                 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, ifd, 0);
68                 close(ifd);
69                 if (-1 == (int)(long)map) {
70                         fprintf(stderr, "cannot mmap %s\n", filename);
71                         return -1;
72                 }
73                 ofd = open(dest_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
74                 status = ((ofd < 0) ||
75                           (write(ofd, map, st.st_size) != st.st_size));
76                 munmap(map, st.st_size);
77                 close(ofd);
78                 if (status)
79                         fprintf(stderr, "cannot write %s (%ld bytes)\n",
80                                 dest_filename, st.st_size);
81                 else
82                         say("copy %s\n", hex);
83                 return status;
84         }
85         fprintf(stderr, "failed to copy %s with given copy methods.\n", hex);
86         return -1;
87 }
88
89 static const char *local_pull_usage = 
90 "git-local-pull [-c] [-t] [-a] [-l] [-s] [-n] [-v] commit-id path";
91
92 /* 
93  * By default we only use file copy.
94  * If -l is specified, a hard link is attempted.
95  * If -s is specified, then a symlink is attempted.
96  * If -n is _not_ specified, then a regular file-to-file copy is done.
97  */
98 int main(int argc, char **argv)
99 {
100         char *commit_id;
101         int arg = 1;
102
103         while (arg < argc && argv[arg][0] == '-') {
104                 if (argv[arg][1] == 't')
105                         get_tree = 1;
106                 else if (argv[arg][1] == 'c')
107                         get_history = 1;
108                 else if (argv[arg][1] == 'a') {
109                         get_all = 1;
110                         get_tree = 1;
111                         get_history = 1;
112                 }
113                 else if (argv[arg][1] == 'l')
114                         use_link = 1;
115                 else if (argv[arg][1] == 's')
116                         use_symlink = 1;
117                 else if (argv[arg][1] == 'n')
118                         use_filecopy = 0;
119                 else if (argv[arg][1] == 'v')
120                         verbose = 1;
121                 else
122                         usage(local_pull_usage);
123                 arg++;
124         }
125         if (argc < arg + 2)
126                 usage(local_pull_usage);
127         commit_id = argv[arg];
128         path = argv[arg + 1];
129
130         if (pull(commit_id))
131                 return 1;
132
133         return 0;
134 }