checkout-cache.c

   1 /*
   2  * Check-out files from the "current cache directory"
   3  *
   4  * Copyright (C) 2005 Linus Torvalds
   5  *
   6  * Careful: order of argument flags does matter. For example,
   7  *
   8  *      checkout-cache -a -f file.c
   9  *
  10  * Will first check out all files listed in the cache (but not
  11  * overwrite any old ones), and then force-checkout "file.c" a
  12  * second time (ie that one _will_ overwrite any old contents
  13  * with the same filename).
  14  *
  15  * Also, just doing "checkout-cache" does nothing. You probably
  16  * meant "checkout-cache -a". And if you want to force it, you
  17  * want "checkout-cache -f -a".
  18  *
  19  * Intuitiveness is not the goal here. Repeatability is. The
  20  * reason for the "no arguments means no work" thing is that
  21  * from scripts you are supposed to be able to do things like
  22  *
  23  *      find . -name '*.h' -print0 | xargs -0 checkout-cache -f --
  24  *
  25  * which will force all existing *.h files to be replaced with
  26  * their cached copies. If an empty command line implied "all",
  27  * then this would force-refresh everything in the cache, which
  28  * was not the point.
  29  *
  30  * Oh, and the "--" is just a good idea when you know the rest
  31  * will be filenames. Just so that you wouldn't have a filename
  32  * of "-a" causing problems (not possible in the above example,
  33  * but get used to it in scripting!).
  34  */
  35 #include "cache.h"
  36
  37 static int force = 0, quiet = 0, not_new = 0;
  38
  39 static void create_directories(const char *path)
  40 {
  41         int len = strlen(path);
  42         char *buf = xmalloc(len + 1);
  43         const char *slash = path;
  44
  45         while ((slash = strchr(slash+1, '/')) != NULL) {
  46                 len = slash - path;
  47                 memcpy(buf, path, len);
  48                 buf[len] = 0;
  49                 mkdir(buf, 0755);
  50         }
  51 }
  52
  53 static int create_file(const char *path, unsigned int mode)
  54 {
  55         int fd;
  56
  57         mode = (mode & 0100) ? 0777 : 0666;
  58         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
  59         if (fd < 0) {
  60                 if (errno == ENOENT) {
  61                         create_directories(path);
  62                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
  63                 }
  64         }
  65         return fd;
  66 }
  67
  68 static int write_entry(struct cache_entry *ce, const char *path)
  69 {
  70         int fd;
  71         void *new;
  72         unsigned long size;
  73         long wrote;
  74         char type[20];
  75         char target[1024];
  76
  77         new = read_sha1_file(ce->sha1, type, &size);
  78         if (!new || strcmp(type, "blob")) {
  79                 return error("checkout-cache: unable to read sha1 file of %s (%s)",
  80                         path, sha1_to_hex(ce->sha1));
  81         }
  82         switch (ntohl(ce->ce_mode) & S_IFMT) {
  83         case S_IFREG:
  84                 fd = create_file(path, ntohl(ce->ce_mode));
  85                 if (fd < 0) {
  86                         free(new);
  87                         return error("checkout-cache: unable to create file %s (%s)",
  88                                 path, strerror(errno));
  89                 }
  90                 wrote = write(fd, new, size);
  91                 close(fd);
  92                 free(new);
  93                 if (wrote != size)
  94                         return error("checkout-cache: unable to write file %s", path);
  95                 break;
  96         case S_IFLNK:
  97                 memcpy(target, new, size);
  98                 target[size] = '\0';
  99                 create_directories(path);
 100                 if (symlink(target, path)) {
 101                         free(new);
 102                         return error("checkout-cache: unable to create symlink %s (%s)",
 103                                 path, strerror(errno));
 104                 }
 105                 free(new);
 106                 break;
 107         default:
 108                 free(new);
 109                 return error("checkout-cache: unknown file mode for %s", path);
 110         }
 111         return 0;
 112 }
 113
 114 static int checkout_entry(struct cache_entry *ce, const char *base_dir)
 115 {
 116         struct stat st;
 117         static char path[MAXPATHLEN+1];
 118         int len = strlen(base_dir);
 119
 120         memcpy(path, base_dir, len);
 121         strcpy(path + len, ce->name);
 122
 123         if (!lstat(path, &st)) {
 124                 unsigned changed = cache_match_stat(ce, &st);
 125                 if (!changed)
 126                         return 0;
 127                 if (!force) {
 128                         if (!quiet)
 129                                 fprintf(stderr, "checkout-cache: %s already exists\n", path);
 130                         return 0;
 131                 }
 132
 133                 /*
 134                  * We unlink the old file, to get the new one with the
 135                  * right permissions (including umask, which is nasty
 136                  * to emulate by hand - much easier to let the system
 137                  * just do the right thing)
 138                  */
 139                 unlink(path);
 140         } else if (not_new)
 141                 return 0;
 142         return write_entry(ce, path);
 143 }
 144
 145 static int checkout_file(const char *name, const char *base_dir)
 146 {
 147         int pos = cache_name_pos(name, strlen(name));
 148         if (pos < 0) {
 149                 if (!quiet) {
 150                         pos = -pos - 1;
 151                         fprintf(stderr,
 152                                 "checkout-cache: %s is %s.\n",
 153                                 name,
 154                                 (pos < active_nr &&
 155                                  !strcmp(active_cache[pos]->name, name)) ?
 156                                 "unmerged" : "not in the cache");
 157                 }
 158                 return -1;
 159         }
 160         return checkout_entry(active_cache[pos], base_dir);
 161 }
 162
 163 static int checkout_all(const char *base_dir)
 164 {
 165         int i;
 166
 167         for (i = 0; i < active_nr ; i++) {
 168                 struct cache_entry *ce = active_cache[i];
 169                 if (ce_stage(ce))
 170                         continue;
 171                 if (checkout_entry(ce, base_dir) < 0)
 172                         return -1;
 173         }
 174         return 0;
 175 }
 176
 177 int main(int argc, char **argv)
 178 {
 179         int i, force_filename = 0;
 180         const char *base_dir = "";
 181
 182         if (read_cache() < 0) {
 183                 die("invalid cache");
 184         }
 185
 186         for (i = 1; i < argc; i++) {
 187                 const char *arg = argv[i];
 188                 if (!force_filename) {
 189                         if (!strcmp(arg, "-a")) {
 190                                 checkout_all(base_dir);
 191                                 continue;
 192                         }
 193                         if (!strcmp(arg, "--")) {
 194                                 force_filename = 1;
 195                                 continue;
 196                         }
 197                         if (!strcmp(arg, "-f")) {
 198                                 force = 1;
 199                                 continue;
 200                         }
 201                         if (!strcmp(arg, "-q")) {
 202                                 quiet = 1;
 203                                 continue;
 204                         }
 205                         if (!strcmp(arg, "-n")) {
 206                                 not_new = 1;
 207                                 continue;
 208                         }
 209                         if (!memcmp(arg, "--prefix=", 9)) {
 210                                 base_dir = arg+9;
 211                                 continue;
 212                         }
 213                 }
 214                 checkout_file(arg, base_dir);
 215         }
 216         return 0;
 217 }