merge-cache.c

   1 #include <sys/types.h>
   2 #include <sys/wait.h>
   3
   4 #include "cache.h"
   5
   6 static const char *pgm = NULL;
   7 static const char *arguments[5];
   8
   9 static void run_program(void)
  10 {
  11         int pid = fork(), status;
  12
  13         if (pid < 0)
  14                 die("unable to fork");
  15         if (!pid) {
  16                 execlp(pgm, arguments[0],
  17                             arguments[1],
  18                             arguments[2],
  19                             arguments[3],
  20                             arguments[4],
  21                             NULL);
  22                 die("unable to execute '%s'", pgm);
  23         }
  24         if (waitpid(pid, &status, 0) < 0 || !WIFEXITED(status) || WEXITSTATUS(status))
  25                 die("merge program failed");
  26 }
  27
  28 static char *create_temp_file(int stage, unsigned char *sha1)
  29 {
  30         static char template[4][50];
  31         char *path = template[stage];
  32         void *buf;
  33         char type[100];
  34         unsigned long size;
  35         int fd;
  36
  37         buf = read_sha1_file(sha1, type, &size);
  38         if (!buf || strcmp(type, "blob"))
  39                 die("unable to read blob object %s", sha1_to_hex(sha1));
  40
  41         strcpy(path, ".merge_file_XXXXXX");
  42         fd = mkstemp(path);
  43         if (fd < 0)
  44                 die("unable to create temp-file");
  45         if (write(fd, buf, size) != size)
  46                 die("unable to write temp-file");
  47         close(fd);
  48         return path;
  49 }
  50
  51 static int merge_entry(int pos, const char *path)
  52 {
  53         int found;
  54
  55         if (pos >= active_nr)
  56                 die("merge-cache: %s not in the cache", path);
  57         arguments[0] = pgm;
  58         arguments[1] = "";
  59         arguments[2] = "";
  60         arguments[3] = "";
  61         arguments[4] = path;
  62         found = 0;
  63         do {
  64                 struct cache_entry *ce = active_cache[pos];
  65                 int stage = ce_stage(ce);
  66
  67                 if (strcmp(ce->name, path))
  68                         break;
  69                 found++;
  70                 arguments[stage] = create_temp_file(stage, ce->sha1);
  71         } while (++pos < active_nr);
  72         if (!found)
  73                 die("merge-cache: %s not in the cache", path);
  74         run_program();
  75         return found;
  76 }
  77
  78 static void merge_file(const char *path)
  79 {
  80         int pos = cache_name_pos(path, strlen(path));
  81
  82         /*
  83          * If it already exists in the cache as stage0, it's
  84          * already merged and there is nothing to do.
  85          */
  86         if (pos < 0)
  87                 merge_entry(-pos-1, path);
  88 }
  89
  90 static void merge_all(void)
  91 {
  92         int i;
  93         for (i = 0; i < active_nr; i++) {
  94                 struct cache_entry *ce = active_cache[i];
  95                 if (!ce_stage(ce))
  96                         continue;
  97                 i += merge_entry(i, ce->name)-1;
  98         }
  99 }
 100
 101 int main(int argc, char **argv)
 102 {
 103         int i, force_file = 0;
 104
 105         if (argc < 3)
 106                 usage("merge-cache <merge-program> (-a | <filename>*)");
 107
 108         read_cache();
 109
 110         pgm = argv[1];
 111         for (i = 2; i < argc; i++) {
 112                 char *arg = argv[i];
 113                 if (!force_file && *arg == '-') {
 114                         if (!strcmp(arg, "--")) {
 115                                 force_file = 1;
 116                                 continue;
 117                         }
 118                         if (!strcmp(arg, "-a")) {
 119                                 merge_all();
 120                                 continue;
 121                         }
 122                         die("merge-cache: unknown option %s", arg);
 123                 }
 124                 merge_file(arg);
 125         }
 126         return 0;
 127 }