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  *      git-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 "git-checkout-cache" does nothing. You probably
  16  * meant "git-checkout-cache -a". And if you want to force it, you
  17  * want "git-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 git-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 struct checkout state = {
  38         .base_dir = "",
  39         .base_dir_len = 0,
  40         .force = 0,
  41         .quiet = 0,
  42         .not_new = 0,
  43         .refresh_cache = 0,
  44 };
  45
  46 static int checkout_file(const char *name)
  47 {
  48         int pos = cache_name_pos(name, strlen(name));
  49         if (pos < 0) {
  50                 if (!state.quiet) {
  51                         pos = -pos - 1;
  52                         fprintf(stderr,
  53                                 "git-checkout-cache: %s is %s.\n",
  54                                 name,
  55                                 (pos < active_nr &&
  56                                  !strcmp(active_cache[pos]->name, name)) ?
  57                                 "unmerged" : "not in the cache");
  58                 }
  59                 return -1;
  60         }
  61         return checkout_entry(active_cache[pos], &state);
  62 }
  63
  64 static int checkout_all(void)
  65 {
  66         int i;
  67
  68         for (i = 0; i < active_nr ; i++) {
  69                 struct cache_entry *ce = active_cache[i];
  70                 if (ce_stage(ce))
  71                         continue;
  72                 if (checkout_entry(ce, &state) < 0)
  73                         return -1;
  74         }
  75         return 0;
  76 }
  77
  78 static const char *checkout_cache_usage =
  79 "git-checkout-cache [-u] [-q] [-a] [-f] [-n] [--prefix=<string>] [--] <file>...";
  80
  81 int main(int argc, char **argv)
  82 {
  83         int i, force_filename = 0;
  84         struct cache_file cache_file;
  85         int newfd = -1;
  86
  87         if (read_cache() < 0) {
  88                 die("invalid cache");
  89         }
  90
  91         for (i = 1; i < argc; i++) {
  92                 const char *arg = argv[i];
  93                 if (!force_filename) {
  94                         if (!strcmp(arg, "-a")) {
  95                                 checkout_all();
  96                                 continue;
  97                         }
  98                         if (!strcmp(arg, "--")) {
  99                                 force_filename = 1;
 100                                 continue;
 101                         }
 102                         if (!strcmp(arg, "-f")) {
 103                                 state.force = 1;
 104                                 continue;
 105                         }
 106                         if (!strcmp(arg, "-q")) {
 107                                 state.quiet = 1;
 108                                 continue;
 109                         }
 110                         if (!strcmp(arg, "-n")) {
 111                                 state.not_new = 1;
 112                                 continue;
 113                         }
 114                         if (!strcmp(arg, "-u")) {
 115                                 state.refresh_cache = 1;
 116                                 if (newfd < 0)
 117                                         newfd = hold_index_file_for_update
 118                                                 (&cache_file,
 119                                                  get_index_file());
 120                                 if (newfd < 0)
 121                                         die("cannot open index.lock file.");
 122                                 continue;
 123                         }
 124                         if (!memcmp(arg, "--prefix=", 9)) {
 125                                 state.base_dir = arg+9;
 126                                 state.base_dir_len = strlen(state.base_dir);
 127                                 continue;
 128                         }
 129                         if (arg[0] == '-')
 130                                 usage(checkout_cache_usage);
 131                 }
 132                 if (state.base_dir_len) {
 133                         /* when --prefix is specified we do not
 134                          * want to update cache.
 135                          */
 136                         if (state.refresh_cache) {
 137                                 close(newfd); newfd = -1;
 138                                 rollback_index_file(&cache_file);
 139                         }
 140                         state.refresh_cache = 0;
 141                 }
 142                 checkout_file(arg);
 143         }
 144
 145         if (0 <= newfd &&
 146             (write_cache(newfd, active_cache, active_nr) ||
 147              commit_index_file(&cache_file)))
 148                 die("Unable to write new cachefile");
 149         return 0;
 150 }