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         free(buf);
  52 }
  53
  54 static int create_file(const char *path, unsigned int mode)
  55 {
  56         int fd;
  57
  58         mode = (mode & 0100) ? 0777 : 0666;
  59         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
  60         if (fd < 0) {
  61                 if (errno == ENOENT) {
  62                         create_directories(path);
  63                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
  64                 }
  65         }
  66         return fd;
  67 }
  68
  69 static int write_entry(struct cache_entry *ce, const char *path)
  70 {
  71         int fd;
  72         void *new;
  73         unsigned long size;
  74         long wrote;
  75         char type[20];
  76         char target[1024];
  77
  78         new = read_sha1_file(ce->sha1, type, &size);
  79         if (!new || strcmp(type, "blob")) {
  80                 return error("checkout-cache: unable to read sha1 file of %s (%s)",
  81                         path, sha1_to_hex(ce->sha1));
  82         }
  83         switch (ntohl(ce->ce_mode) & S_IFMT) {
  84         case S_IFREG:
  85                 fd = create_file(path, ntohl(ce->ce_mode));
  86                 if (fd < 0) {
  87                         free(new);
  88                         return error("checkout-cache: unable to create file %s (%s)",
  89                                 path, strerror(errno));
  90                 }
  91                 wrote = write(fd, new, size);
  92                 close(fd);
  93                 free(new);
  94                 if (wrote != size)
  95                         return error("checkout-cache: unable to write file %s", path);
  96                 break;
  97         case S_IFLNK:
  98                 memcpy(target, new, size);
  99                 target[size] = '\0';
 100                 create_directories(path);
 101                 if (symlink(target, path)) {
 102                         free(new);
 103                         return error("checkout-cache: unable to create symlink %s (%s)",
 104                                 path, strerror(errno));
 105                 }
 106                 free(new);
 107                 break;
 108         default:
 109                 free(new);
 110                 return error("checkout-cache: unknown file mode for %s", path);
 111         }
 112         return 0;
 113 }
 114
 115 static int checkout_entry(struct cache_entry *ce, const char *base_dir)
 116 {
 117         struct stat st;
 118         static char path[MAXPATHLEN+1];
 119         int len = strlen(base_dir);
 120
 121         memcpy(path, base_dir, len);
 122         strcpy(path + len, ce->name);
 123
 124         if (!lstat(path, &st)) {
 125                 unsigned changed = cache_match_stat(ce, &st);
 126                 if (!changed)
 127                         return 0;
 128                 if (!force) {
 129                         if (!quiet)
 130                                 fprintf(stderr, "checkout-cache: %s already exists\n", path);
 131                         return 0;
 132                 }
 133
 134                 /*
 135                  * We unlink the old file, to get the new one with the
 136                  * right permissions (including umask, which is nasty
 137                  * to emulate by hand - much easier to let the system
 138                  * just do the right thing)
 139                  */
 140                 unlink(path);
 141         } else if (not_new)
 142                 return 0;
 143         return write_entry(ce, path);
 144 }
 145
 146 static int checkout_file(const char *name, const char *base_dir)
 147 {
 148         int pos = cache_name_pos(name, strlen(name));
 149         if (pos < 0) {
 150                 if (!quiet) {
 151                         pos = -pos - 1;
 152                         fprintf(stderr,
 153                                 "checkout-cache: %s is %s.\n",
 154                                 name,
 155                                 (pos < active_nr &&
 156                                  !strcmp(active_cache[pos]->name, name)) ?
 157                                 "unmerged" : "not in the cache");
 158                 }
 159                 return -1;
 160         }
 161         return checkout_entry(active_cache[pos], base_dir);
 162 }
 163
 164 static int checkout_all(const char *base_dir)
 165 {
 166         int i;
 167
 168         for (i = 0; i < active_nr ; i++) {
 169                 struct cache_entry *ce = active_cache[i];
 170                 if (ce_stage(ce))
 171                         continue;
 172                 if (checkout_entry(ce, base_dir) < 0)
 173                         return -1;
 174         }
 175         return 0;
 176 }
 177
 178 int main(int argc, char **argv)
 179 {
 180         int i, force_filename = 0;
 181         const char *base_dir = "";
 182
 183         if (read_cache() < 0) {
 184                 die("invalid cache");
 185         }
 186
 187         for (i = 1; i < argc; i++) {
 188                 const char *arg = argv[i];
 189                 if (!force_filename) {
 190                         if (!strcmp(arg, "-a")) {
 191                                 checkout_all(base_dir);
 192                                 continue;
 193                         }
 194                         if (!strcmp(arg, "--")) {
 195                                 force_filename = 1;
 196                                 continue;
 197                         }
 198                         if (!strcmp(arg, "-f")) {
 199                                 force = 1;
 200                                 continue;
 201                         }
 202                         if (!strcmp(arg, "-q")) {
 203                                 quiet = 1;
 204                                 continue;
 205                         }
 206                         if (!strcmp(arg, "-n")) {
 207                                 not_new = 1;
 208                                 continue;
 209                         }
 210                         if (!memcmp(arg, "--prefix=", 9)) {
 211                                 base_dir = arg+9;
 212                                 continue;
 213                         }
 214                 }
 215                 checkout_file(arg, base_dir);
 216         }
 217         return 0;
 218 }