init-db.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7
   8 static void safe_create_dir(const char *dir)
   9 {
  10         if (mkdir(dir, 0777) < 0) {
  11                 if (errno != EEXIST) {
  12                         perror(dir);
  13                         exit(1);
  14                 }
  15         }
  16 }
  17
  18 static int copy_file(const char *dst, const char *src, int mode)
  19 {
  20         int fdi, fdo;
  21
  22         mode = (mode & 0111) ? 0777 : 0666;
  23         if ((fdi = open(src, O_RDONLY)) < 0)
  24                 return fdi;
  25         if ((fdo = open(dst, O_WRONLY | O_CREAT | O_EXCL, mode)) < 0) {
  26                 close(fdi);
  27                 return fdo;
  28         }
  29         while (1) {
  30                 char buf[BUFSIZ];
  31                 ssize_t leni, leno, ofs;
  32                 leni = read(fdi, buf, sizeof(buf));
  33                 if (leni < 0) {
  34                 error_return:
  35                         close(fdo);
  36                         close(fdi);
  37                         return -1;
  38                 }
  39                 if (!leni)
  40                         break;
  41                 ofs = 0;
  42                 do {
  43                         leno = write(fdo, buf+ofs, leni);
  44                         if (leno < 0)
  45                                 goto error_return;
  46                         leni -= leno;
  47                         ofs += leno;
  48                 } while (0 < leni);
  49         }
  50         close(fdo);
  51         close(fdi);
  52         return 0;
  53 }
  54
  55 static void copy_templates_1(char *path, int baselen,
  56                              char *template, int template_baselen,
  57                              DIR *dir)
  58 {
  59         struct dirent *de;
  60
  61         /* Note: if ".git/hooks" file exists in the repository being
  62          * re-initialized, /etc/core-git/templates/hooks/update would
  63          * cause git-init-db to fail here.  I think this is sane but
  64          * it means that the set of templates we ship by default, along
  65          * with the way the namespace under .git/ is organized, should
  66          * be really carefully chosen.
  67          */
  68         safe_create_dir(path);
  69         while ((de = readdir(dir)) != NULL) {
  70                 struct stat st_git, st_template;
  71                 int namelen;
  72                 int exists = 0;
  73
  74                 if (de->d_name[0] == '.')
  75                         continue;
  76                 namelen = strlen(de->d_name);
  77                 if ((PATH_MAX <= baselen + namelen) ||
  78                     (PATH_MAX <= template_baselen + namelen))
  79                         die("insanely long template name %s", de->d_name);
  80                 memcpy(path + baselen, de->d_name, namelen+1);
  81                 memcpy(template + template_baselen, de->d_name, namelen+1);
  82                 if (lstat(path, &st_git)) {
  83                         if (errno != ENOENT)
  84                                 die("cannot stat %s", path);
  85                 }
  86                 else
  87                         exists = 1;
  88
  89                 if (lstat(template, &st_template))
  90                         die("cannot stat template %s", template);
  91
  92                 if (S_ISDIR(st_template.st_mode)) {
  93                         DIR *subdir = opendir(template);
  94                         int baselen_sub = baselen + namelen;
  95                         int template_baselen_sub = template_baselen + namelen;
  96                         if (!subdir)
  97                                 die("cannot opendir %s", template);
  98                         path[baselen_sub++] =
  99                                 template[template_baselen_sub++] = '/';
 100                         path[baselen_sub] =
 101                                 template[template_baselen_sub] = 0;
 102                         copy_templates_1(path, baselen_sub,
 103                                          template, template_baselen_sub,
 104                                          subdir);
 105                         closedir(subdir);
 106                 }
 107                 else if (exists)
 108                         continue;
 109                 else if (S_ISLNK(st_template.st_mode)) {
 110                         char lnk[256];
 111                         int len;
 112                         len = readlink(template, lnk, sizeof(lnk));
 113                         if (len < 0)
 114                                 die("cannot readlink %s", template);
 115                         if (sizeof(lnk) <= len)
 116                                 die("insanely long symlink %s", template);
 117                         lnk[len] = 0;
 118                         if (symlink(lnk, path))
 119                                 die("cannot symlink %s %s", lnk, path);
 120                 }
 121                 else if (S_ISREG(st_template.st_mode)) {
 122                         if (copy_file(path, template, st_template.st_mode))
 123                                 die("cannot copy %s to %s", template, path);
 124                 }
 125                 else
 126                         error("ignoring template %s", template);
 127         }
 128 }
 129
 130 static void copy_templates(const char *git_dir)
 131 {
 132         char path[PATH_MAX];
 133         char template_path[PATH_MAX];
 134         char *template_dir;
 135         int len, template_len;
 136         DIR *dir;
 137
 138         strcpy(path, git_dir);
 139         len = strlen(path);
 140         template_dir = gitenv(TEMPLATE_DIR_ENVIRONMENT);
 141         if (!template_dir)
 142                 template_dir = DEFAULT_GIT_TEMPLATE_ENVIRONMENT;
 143         strcpy(template_path, template_dir);
 144         template_len = strlen(template_path);
 145         if (template_path[template_len-1] != '/') {
 146                 template_path[template_len++] = '/';
 147                 template_path[template_len] = 0;
 148         }
 149
 150         dir = opendir(template_path);
 151         if (!dir)
 152                 return;
 153         copy_templates_1(path, len,
 154                          template_path, template_len,
 155                          dir);
 156         closedir(dir);
 157 }
 158
 159 static void create_default_files(const char *git_dir)
 160 {
 161         unsigned len = strlen(git_dir);
 162         static char path[PATH_MAX];
 163
 164         if (len > sizeof(path)-50)
 165                 die("insane git directory %s", git_dir);
 166         memcpy(path, git_dir, len);
 167
 168         if (len && path[len-1] != '/')
 169                 path[len++] = '/';
 170
 171         /*
 172          * Create .git/refs/{heads,tags}
 173          */
 174         strcpy(path + len, "refs");
 175         safe_create_dir(path);
 176         strcpy(path + len, "refs/heads");
 177         safe_create_dir(path);
 178         strcpy(path + len, "refs/tags");
 179         safe_create_dir(path);
 180
 181         /*
 182          * Create the default symlink from ".git/HEAD" to the "master"
 183          * branch
 184          */
 185         strcpy(path + len, "HEAD");
 186         if (symlink("refs/heads/master", path) < 0) {
 187                 if (errno != EEXIST) {
 188                         perror(path);
 189                         exit(1);
 190                 }
 191         }
 192         copy_templates(path);
 193 }
 194
 195 /*
 196  * If you want to, you can share the DB area with any number of branches.
 197  * That has advantages: you can save space by sharing all the SHA1 objects.
 198  * On the other hand, it might just make lookup slower and messier. You
 199  * be the judge.  The default case is to have one DB per managed directory.
 200  */
 201 int main(int argc, char **argv)
 202 {
 203         const char *git_dir;
 204         const char *sha1_dir;
 205         char *path;
 206         int len, i;
 207
 208         /*
 209          * Set up the default .git directory contents
 210          */
 211         git_dir = gitenv(GIT_DIR_ENVIRONMENT);
 212         if (!git_dir) {
 213                 git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 214                 fprintf(stderr, "defaulting to local storage area\n");
 215         }
 216         safe_create_dir(git_dir);
 217         create_default_files(git_dir);
 218
 219         /*
 220          * And set up the object store.
 221          */
 222         sha1_dir = get_object_directory();
 223         len = strlen(sha1_dir);
 224         path = xmalloc(len + 40);
 225         memcpy(path, sha1_dir, len);
 226
 227         safe_create_dir(sha1_dir);
 228         for (i = 0; i < 256; i++) {
 229                 sprintf(path+len, "/%02x", i);
 230                 safe_create_dir(path);
 231         }
 232         strcpy(path+len, "/pack");
 233         safe_create_dir(path);
 234         return 0;
 235 }