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 <sys/param.h>
  36
  37 #include "cache.h"
  38
  39 static int force = 0, quiet = 0;
  40
  41 static void create_directories(const char *path)
  42 {
  43         int len = strlen(path);
  44         char *buf = malloc(len + 1);
  45         const char *slash = path;
  46
  47         while ((slash = strchr(slash+1, '/')) != NULL) {
  48                 len = slash - path;
  49                 memcpy(buf, path, len);
  50                 buf[len] = 0;
  51                 mkdir(buf, 0755);
  52         }
  53 }
  54
  55 static int create_file(const char *path, unsigned int mode)
  56 {
  57         int fd;
  58
  59         mode = (mode & 0100) ? 0777 : 0666;
  60         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
  61         if (fd < 0) {
  62                 if (errno == ENOENT) {
  63                         create_directories(path);
  64                         fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
  65                 }
  66         }
  67         return fd;
  68 }
  69
  70 static int write_entry(struct cache_entry *ce, const char *path)
  71 {
  72         int fd;
  73         void *new;
  74         unsigned long size;
  75         long wrote;
  76         char type[20];
  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         fd = create_file(path, ntohl(ce->ce_mode));
  84         if (fd < 0) {
  85                 free(new);
  86                 return error("checkout-cache: unable to create %s (%s)",
  87                         path, strerror(errno));
  88         }
  89         wrote = write(fd, new, size);
  90         close(fd);
  91         free(new);
  92         if (wrote != size)
  93                 return error("checkout-cache: unable to write %s", path);
  94         return 0;
  95 }
  96
  97 static int checkout_entry(struct cache_entry *ce, const char *base_dir)
  98 {
  99         struct stat st;
 100         static char path[MAXPATHLEN+1];
 101         int len = strlen(base_dir);
 102
 103         memcpy(path, base_dir, len);
 104         strcpy(path + len, ce->name);
 105
 106         if (!stat(path, &st)) {
 107                 unsigned changed = cache_match_stat(ce, &st);
 108                 if (!changed)
 109                         return 0;
 110                 if (!force) {
 111                         if (!quiet)
 112                                 fprintf(stderr, "checkout-cache: %s already exists\n", path);
 113                         return 0;
 114                 }
 115
 116                 /*
 117                  * We unlink the old file, to get the new one with the
 118                  * right permissions (including umask, which is nasty
 119                  * to emulate by hand - much easier to let the system
 120                  * just do the right thing)
 121                  */
 122                 unlink(path);
 123         }
 124         return write_entry(ce, path);
 125 }
 126
 127 static int checkout_file(const char *name, const char *base_dir)
 128 {
 129         int pos = cache_name_pos(name, strlen(name));
 130         if (pos < 0) {
 131                 if (!quiet) {
 132                         pos = -pos - 1;
 133                         fprintf(stderr,
 134                                 "checkout-cache: %s is %s.\n",
 135                                 name,
 136                                 (pos < active_nr &&
 137                                  !strcmp(active_cache[pos]->name, name)) ?
 138                                 "unmerged" : "not in the cache");
 139                 }
 140                 return -1;
 141         }
 142         return checkout_entry(active_cache[pos], base_dir);
 143 }
 144
 145 static int checkout_all(const char *base_dir)
 146 {
 147         int i;
 148
 149         for (i = 0; i < active_nr ; i++) {
 150                 struct cache_entry *ce = active_cache[i];
 151                 if (ce_stage(ce))
 152                         continue;
 153                 if (checkout_entry(ce, base_dir) < 0)
 154                         return -1;
 155         }
 156         return 0;
 157 }
 158
 159 int main(int argc, char **argv)
 160 {
 161         int i, force_filename = 0;
 162         const char *base_dir = "";
 163
 164         if (read_cache() < 0) {
 165                 die("invalid cache");
 166         }
 167
 168         for (i = 1; i < argc; i++) {
 169                 const char *arg = argv[i];
 170                 if (!force_filename) {
 171                         if (!strcmp(arg, "-a")) {
 172                                 checkout_all(base_dir);
 173                                 continue;
 174                         }
 175                         if (!strcmp(arg, "--")) {
 176                                 force_filename = 1;
 177                                 continue;
 178                         }
 179                         if (!strcmp(arg, "-f")) {
 180                                 force = 1;
 181                                 continue;
 182                         }
 183                         if (!strcmp(arg, "-q")) {
 184                                 quiet = 1;
 185                                 continue;
 186                         }
 187                         if (!memcmp(arg, "--prefix=", 9)) {
 188                                 base_dir = arg+9;
 189                                 continue;
 190                         }
 191                 }
 192                 checkout_file(arg, base_dir);
 193         }
 194         return 0;
 195 }