convert-objects.c

   1 #define _XOPEN_SOURCE 500 /* glibc2 and AIX 5.3L need this */
   2 #define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
   3 #define _GNU_SOURCE
   4 #include <time.h>
   5 #include "cache.h"
   6 #include "blob.h"
   7 #include "commit.h"
   8 #include "tree.h"
   9
  10 struct entry {
  11         unsigned char old_sha1[20];
  12         unsigned char new_sha1[20];
  13         int converted;
  14 };
  15
  16 #define MAXOBJECTS (1000000)
  17
  18 static struct entry *convert[MAXOBJECTS];
  19 static int nr_convert;
  20
  21 static struct entry * convert_entry(unsigned char *sha1);
  22
  23 static struct entry *insert_new(unsigned char *sha1, int pos)
  24 {
  25         struct entry *new = xcalloc(1, sizeof(struct entry));
  26         memcpy(new->old_sha1, sha1, 20);
  27         memmove(convert + pos + 1, convert + pos, (nr_convert - pos) * sizeof(struct entry *));
  28         convert[pos] = new;
  29         nr_convert++;
  30         if (nr_convert == MAXOBJECTS)
  31                 die("you're kidding me - hit maximum object limit");
  32         return new;
  33 }
  34
  35 static struct entry *lookup_entry(unsigned char *sha1)
  36 {
  37         int low = 0, high = nr_convert;
  38
  39         while (low < high) {
  40                 int next = (low + high) / 2;
  41                 struct entry *n = convert[next];
  42                 int cmp = memcmp(sha1, n->old_sha1, 20);
  43                 if (!cmp)
  44                         return n;
  45                 if (cmp < 0) {
  46                         high = next;
  47                         continue;
  48                 }
  49                 low = next+1;
  50         }
  51         return insert_new(sha1, low);
  52 }
  53
  54 static void convert_binary_sha1(void *buffer)
  55 {
  56         struct entry *entry = convert_entry(buffer);
  57         memcpy(buffer, entry->new_sha1, 20);
  58 }
  59
  60 static void convert_ascii_sha1(void *buffer)
  61 {
  62         unsigned char sha1[20];
  63         struct entry *entry;
  64
  65         if (get_sha1_hex(buffer, sha1))
  66                 die("expected sha1, got '%s'", (char*) buffer);
  67         entry = convert_entry(sha1);
  68         memcpy(buffer, sha1_to_hex(entry->new_sha1), 40);
  69 }
  70
  71 static unsigned int convert_mode(unsigned int mode)
  72 {
  73         unsigned int newmode;
  74
  75         newmode = mode & S_IFMT;
  76         if (S_ISREG(mode))
  77                 newmode |= (mode & 0100) ? 0755 : 0644;
  78         return newmode;
  79 }
  80
  81 static int write_subdirectory(void *buffer, unsigned long size, const char *base, int baselen, unsigned char *result_sha1)
  82 {
  83         char *new = xmalloc(size);
  84         unsigned long newlen = 0;
  85         unsigned long used;
  86
  87         used = 0;
  88         while (size) {
  89                 int len = 21 + strlen(buffer);
  90                 char *path = strchr(buffer, ' ');
  91                 unsigned char *sha1;
  92                 unsigned int mode;
  93                 char *slash, *origpath;
  94
  95                 if (!path || sscanf(buffer, "%o", &mode) != 1)
  96                         die("bad tree conversion");
  97                 mode = convert_mode(mode);
  98                 path++;
  99                 if (memcmp(path, base, baselen))
 100                         break;
 101                 origpath = path;
 102                 path += baselen;
 103                 slash = strchr(path, '/');
 104                 if (!slash) {
 105                         newlen += sprintf(new + newlen, "%o %s", mode, path);
 106                         new[newlen++] = '\0';
 107                         memcpy(new + newlen, (char *) buffer + len - 20, 20);
 108                         newlen += 20;
 109
 110                         used += len;
 111                         size -= len;
 112                         buffer = (char *) buffer + len;
 113                         continue;
 114                 }
 115
 116                 newlen += sprintf(new + newlen, "%o %.*s", S_IFDIR, (int)(slash - path), path);
 117                 new[newlen++] = 0;
 118                 sha1 = (unsigned char *)(new + newlen);
 119                 newlen += 20;
 120
 121                 len = write_subdirectory(buffer, size, origpath, slash-origpath+1, sha1);
 122
 123                 used += len;
 124                 size -= len;
 125                 buffer = (char *) buffer + len;
 126         }
 127
 128         write_sha1_file(new, newlen, tree_type, result_sha1);
 129         free(new);
 130         return used;
 131 }
 132
 133 static void convert_tree(void *buffer, unsigned long size, unsigned char *result_sha1)
 134 {
 135         void *orig_buffer = buffer;
 136         unsigned long orig_size = size;
 137
 138         while (size) {
 139                 int len = 1+strlen(buffer);
 140
 141                 convert_binary_sha1((char *) buffer + len);
 142
 143                 len += 20;
 144                 if (len > size)
 145                         die("corrupt tree object");
 146                 size -= len;
 147                 buffer = (char *) buffer + len;
 148         }
 149
 150         write_subdirectory(orig_buffer, orig_size, "", 0, result_sha1);
 151 }
 152
 153 static unsigned long parse_oldstyle_date(const char *buf)
 154 {
 155         char c, *p;
 156         char buffer[100];
 157         struct tm tm;
 158         const char *formats[] = {
 159                 "%c",
 160                 "%a %b %d %T",
 161                 "%Z",
 162                 "%Y",
 163                 " %Y",
 164                 NULL
 165         };
 166         /* We only ever did two timezones in the bad old format .. */
 167         const char *timezones[] = {
 168                 "PDT", "PST", "CEST", NULL
 169         };
 170         const char **fmt = formats;
 171
 172         p = buffer;
 173         while (isspace(c = *buf))
 174                 buf++;
 175         while ((c = *buf++) != '\n')
 176                 *p++ = c;
 177         *p++ = 0;
 178         buf = buffer;
 179         memset(&tm, 0, sizeof(tm));
 180         do {
 181                 const char *next = strptime(buf, *fmt, &tm);
 182                 if (next) {
 183                         if (!*next)
 184                                 return mktime(&tm);
 185                         buf = next;
 186                 } else {
 187                         const char **p = timezones;
 188                         while (isspace(*buf))
 189                                 buf++;
 190                         while (*p) {
 191                                 if (!memcmp(buf, *p, strlen(*p))) {
 192                                         buf += strlen(*p);
 193                                         break;
 194                                 }
 195                                 p++;
 196                         }
 197                 }
 198                 fmt++;
 199         } while (*buf && *fmt);
 200         printf("left: %s\n", buf);
 201         return mktime(&tm);
 202 }
 203
 204 static int convert_date_line(char *dst, void **buf, unsigned long *sp)
 205 {
 206         unsigned long size = *sp;
 207         char *line = *buf;
 208         char *next = strchr(line, '\n');
 209         char *date = strchr(line, '>');
 210         int len;
 211
 212         if (!next || !date)
 213                 die("missing or bad author/committer line %s", line);
 214         next++; date += 2;
 215
 216         *buf = next;
 217         *sp = size - (next - line);
 218
 219         len = date - line;
 220         memcpy(dst, line, len);
 221         dst += len;
 222
 223         /* Is it already in new format? */
 224         if (isdigit(*date)) {
 225                 int datelen = next - date;
 226                 memcpy(dst, date, datelen);
 227                 return len + datelen;
 228         }
 229
 230         /*
 231          * Hacky hacky: one of the sparse old-style commits does not have
 232          * any date at all, but we can fake it by using the committer date.
 233          */
 234         if (*date == '\n' && strchr(next, '>'))
 235                 date = strchr(next, '>')+2;
 236
 237         return len + sprintf(dst, "%lu -0700\n", parse_oldstyle_date(date));
 238 }
 239
 240 static void convert_date(void *buffer, unsigned long size, unsigned char *result_sha1)
 241 {
 242         char *new = xmalloc(size + 100);
 243         unsigned long newlen = 0;
 244
 245         /* "tree <sha1>\n" */
 246         memcpy(new + newlen, buffer, 46);
 247         newlen += 46;
 248         buffer = (char *) buffer + 46;
 249         size -= 46;
 250
 251         /* "parent <sha1>\n" */
 252         while (!memcmp(buffer, "parent ", 7)) {
 253                 memcpy(new + newlen, buffer, 48);
 254                 newlen += 48;
 255                 buffer = (char *) buffer + 48;
 256                 size -= 48;
 257         }
 258
 259         /* "author xyz <xyz> date" */
 260         newlen += convert_date_line(new + newlen, &buffer, &size);
 261         /* "committer xyz <xyz> date" */
 262         newlen += convert_date_line(new + newlen, &buffer, &size);
 263
 264         /* Rest */
 265         memcpy(new + newlen, buffer, size);
 266         newlen += size;
 267
 268         write_sha1_file(new, newlen, commit_type, result_sha1);
 269         free(new);
 270 }
 271
 272 static void convert_commit(void *buffer, unsigned long size, unsigned char *result_sha1)
 273 {
 274         void *orig_buffer = buffer;
 275         unsigned long orig_size = size;
 276
 277         if (memcmp(buffer, "tree ", 5))
 278                 die("Bad commit '%s'", (char*) buffer);
 279         convert_ascii_sha1((char *) buffer + 5);
 280         buffer = (char *) buffer + 46;    /* "tree " + "hex sha1" + "\n" */
 281         while (!memcmp(buffer, "parent ", 7)) {
 282                 convert_ascii_sha1((char *) buffer + 7);
 283                 buffer = (char *) buffer + 48;
 284         }
 285         convert_date(orig_buffer, orig_size, result_sha1);
 286 }
 287
 288 static struct entry * convert_entry(unsigned char *sha1)
 289 {
 290         struct entry *entry = lookup_entry(sha1);
 291         char type[20];
 292         void *buffer, *data;
 293         unsigned long size;
 294
 295         if (entry->converted)
 296                 return entry;
 297         data = read_sha1_file(sha1, type, &size);
 298         if (!data)
 299                 die("unable to read object %s", sha1_to_hex(sha1));
 300
 301         buffer = xmalloc(size);
 302         memcpy(buffer, data, size);
 303
 304         if (!strcmp(type, blob_type)) {
 305                 write_sha1_file(buffer, size, blob_type, entry->new_sha1);
 306         } else if (!strcmp(type, tree_type))
 307                 convert_tree(buffer, size, entry->new_sha1);
 308         else if (!strcmp(type, commit_type))
 309                 convert_commit(buffer, size, entry->new_sha1);
 310         else
 311                 die("unknown object type '%s' in %s", type, sha1_to_hex(sha1));
 312         entry->converted = 1;
 313         free(buffer);
 314         free(data);
 315         return entry;
 316 }
 317
 318 int main(int argc, char **argv)
 319 {
 320         unsigned char sha1[20];
 321         struct entry *entry;
 322
 323         setup_git_directory();
 324
 325         if (argc != 2)
 326                 usage("git-convert-objects <sha1>");
 327         if (get_sha1(argv[1], sha1))
 328                 die("Not a valid object name %s", argv[1]);
 329
 330         entry = convert_entry(sha1);
 331         printf("new sha1: %s\n", sha1_to_hex(entry->new_sha1));
 332         return 0;
 333 }