rev-tree.c

   1 #define _XOPEN_SOURCE /* glibc2 needs this */
   2 #define _BSD_SOURCE /* for tm.tm_gmtoff */
   3 #include <time.h>
   4 #include <ctype.h>
   5
   6 #include "cache.h"
   7 #include "revision.h"
   8
   9 /*
  10  * revision.h leaves the low 16 bits of the "flags" field of the
  11  * revision data structure unused. We use it for a "reachable from
  12  * this commit <N>" bitmask.
  13  */
  14 #define MAX_COMMITS 16
  15
  16 static int show_edges = 0;
  17 static int basemask = 0;
  18
  19 static void read_cache_file(const char *path)
  20 {
  21         FILE *file = fopen(path, "r");
  22         char line[500];
  23
  24         if (!file)
  25                 die("bad revtree cache file (%s)", path);
  26
  27         while (fgets(line, sizeof(line), file)) {
  28                 unsigned long date;
  29                 unsigned char sha1[20];
  30                 struct revision *rev;
  31                 const char *buf;
  32
  33                 if (sscanf(line, "%lu", &date) != 1)
  34                         break;
  35                 buf = strchr(line, ' ');
  36                 if (!buf)
  37                         break;
  38                 if (get_sha1_hex(buf+1, sha1))
  39                         break;
  40                 rev = lookup_rev(sha1);
  41                 rev->flags |= SEEN;
  42                 rev->date = date;
  43
  44                 /* parents? */
  45                 while ((buf = strchr(buf+1, ' ')) != NULL) {
  46                         unsigned char parent[20];
  47                         if (get_sha1_hex(buf + 1, parent))
  48                                 break;
  49                         add_relationship(rev, parent);
  50                 }
  51         }
  52         fclose(file);
  53 }
  54
  55 /*
  56  * Some revisions are less interesting than others.
  57  *
  58  * For example, if we use a cache-file, that one may contain
  59  * revisions that were never used. They are never interesting.
  60  *
  61  * And sometimes we're only interested in "edge" commits, ie
  62  * places where the marking changes between parent and child.
  63  */
  64 static int interesting(struct revision *rev)
  65 {
  66         unsigned mask = marked(rev);
  67
  68         if (!mask)
  69                 return 0;
  70         if (show_edges) {
  71                 struct parent *p = rev->parent;
  72                 while (p) {
  73                         if (mask != marked(p->parent))
  74                                 return 1;
  75                         p = p->next;
  76                 }
  77                 return 0;
  78         }
  79         if (mask & basemask)
  80                 return 0;
  81
  82         return 1;
  83 }
  84
  85 /*
  86  * Usage: rev-tree [--edges] [--cache <cache-file>] <commit-id> [<commit-id2>]
  87  *
  88  * The cache-file can be quite important for big trees. This is an
  89  * expensive operation if you have to walk the whole chain of
  90  * parents in a tree with a long revision history.
  91  */
  92 int main(int argc, char **argv)
  93 {
  94         int i;
  95         int nr = 0;
  96         unsigned char sha1[MAX_COMMITS][20];
  97
  98         /*
  99          * First - pick up all the revisions we can (both from
 100          * caches and from commit file chains).
 101          */
 102         for (i = 1; i < argc ; i++) {
 103                 char *arg = argv[i];
 104
 105                 if (!strcmp(arg, "--cache")) {
 106                         read_cache_file(argv[2]);
 107                         i++;
 108                         continue;
 109                 }
 110
 111                 if (!strcmp(arg, "--edges")) {
 112                         show_edges = 1;
 113                         continue;
 114                 }
 115
 116                 if (arg[0] == '^') {
 117                         arg++;
 118                         basemask |= 1<<nr;
 119                 }
 120                 if (nr >= MAX_COMMITS || get_sha1_hex(arg, sha1[nr]))
 121                         usage("rev-tree [--edges] [--cache <cache-file>] <commit-id> [<commit-id>]");
 122                 parse_commit(sha1[nr]);
 123                 nr++;
 124         }
 125
 126         /*
 127          * Now we have the maximal tree. Walk the different sha files back to the root.
 128          */
 129         for (i = 0; i < nr; i++)
 130                 mark_reachable(lookup_rev(sha1[i]), 1 << i);
 131
 132         /*
 133          * Now print out the results..
 134          */
 135         for (i = 0; i < nr_revs; i++) {
 136                 struct revision *rev = revs[i];
 137                 struct parent *p;
 138
 139                 if (!interesting(rev))
 140                         continue;
 141
 142                 printf("%lu %s:%d", rev->date, sha1_to_hex(rev->sha1), marked(rev));
 143                 p = rev->parent;
 144                 while (p) {
 145                         printf(" %s:%d", sha1_to_hex(p->parent->sha1), marked(p->parent));
 146                         p = p->next;
 147                 }
 148                 printf("\n");
 149         }
 150         return 0;
 151 }