Andrew's git - gitweb.git/blob

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