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("bad sha1");
  64        entry = convert_entry(sha1);
  65        memcpy(buffer, sha1_to_hex(entry->new_sha1), 40);
  66}
  67
  68static int write_subdirectory(void *buffer, unsigned long size, const char *base, int baselen, unsigned char *result_sha1)
  69{
  70        char *new = xmalloc(size);
  71        unsigned long newlen = 0;
  72        unsigned long used;
  73
  74        used = 0;
  75        while (size) {
  76                int len = 21 + strlen(buffer);
  77                char *path = strchr(buffer, ' ');
  78                unsigned char *sha1;
  79                unsigned int mode;
  80                char *slash, *origpath;
  81
  82                if (!path || sscanf(buffer, "%o", &mode) != 1)
  83                        die("bad tree conversion");
  84                path++;
  85                if (memcmp(path, base, baselen))
  86                        break;
  87                origpath = path;
  88                path += baselen;
  89                slash = strchr(path, '/');
  90                if (!slash) {
  91                        newlen += sprintf(new + newlen, "%o %s", mode, path);
  92                        new[newlen++] = '\0';
  93                        memcpy(new + newlen, buffer + len - 20, 20);
  94                        newlen += 20;
  95
  96                        used += len;
  97                        size -= len;
  98                        buffer += len;
  99                        continue;
 100                }
 101
 102                newlen += sprintf(new + newlen, "%o %.*s", S_IFDIR, (int)(slash - path), path);
 103                new[newlen++] = 0;
 104                sha1 = (unsigned char *)(new + newlen);
 105                newlen += 20;
 106
 107                len = write_subdirectory(buffer, size, origpath, slash-origpath+1, sha1);
 108
 109                used += len;
 110                size -= len;
 111                buffer += len;
 112        }
 113
 114        write_sha1_file(new, newlen, "tree", result_sha1);
 115        free(new);
 116        return used;
 117}
 118
 119static int convert_mode(char *buffer)
 120{
 121        char *end;
 122        unsigned short mode = strtoul(buffer, &end, 8);
 123        unsigned short newmode;
 124        char num[10];
 125        int len;
 126
 127        if (*end != ' ')
 128                die("corrupt tree object");
 129        switch (mode) {
 130        case S_IFREG | 0644:
 131        case S_IFREG | 0755:
 132        case S_IFLNK:
 133        case S_IFDIR:
 134                return 0;
 135        }
 136        newmode = 0;
 137        if (S_ISREG(mode))
 138                newmode = (mode & 0100) ? 0755 : 0644;
 139        newmode |= mode & S_IFMT;
 140        len = sprintf(num, "%o", newmode);
 141        if (len != end - buffer)
 142                return error("unable to convert tree entry mode %o to %o", mode, newmode);
 143        memcpy(buffer, num, len);
 144        return 0;
 145}
 146
 147static void convert_tree(void *buffer, unsigned long size, unsigned char *result_sha1)
 148{
 149        void *orig_buffer = buffer;
 150        unsigned long orig_size = size;
 151
 152        while (size) {
 153                int len = 1+strlen(buffer);
 154
 155                convert_mode(buffer);
 156                convert_binary_sha1(buffer + len);
 157
 158                len += 20;
 159                if (len > size)
 160                        die("corrupt tree object");
 161                size -= len;
 162                buffer += len;
 163        }
 164
 165        write_subdirectory(orig_buffer, orig_size, "", 0, result_sha1);
 166}
 167
 168static unsigned long parse_oldstyle_date(const char *buf)
 169{
 170        char c, *p;
 171        char buffer[100];
 172        struct tm tm;
 173        const char *formats[] = {
 174                "%c",
 175                "%a %b %d %T",
 176                "%Z",
 177                "%Y",
 178                " %Y",
 179                NULL
 180        };
 181        /* We only ever did two timezones in the bad old format .. */
 182        const char *timezones[] = {
 183                "PDT", "PST", "CEST", NULL
 184        };
 185        const char **fmt = formats;
 186
 187        p = buffer;
 188        while (isspace(c = *buf))
 189                buf++;
 190        while ((c = *buf++) != '\n')
 191                *p++ = c;
 192        *p++ = 0;
 193        buf = buffer;
 194        memset(&tm, 0, sizeof(tm));
 195        do {
 196                const char *next = strptime(buf, *fmt, &tm);
 197                if (next) {
 198                        if (!*next)
 199                                return mktime(&tm);
 200                        buf = next;
 201                } else {
 202                        const char **p = timezones;
 203                        while (isspace(*buf))
 204                                buf++;
 205                        while (*p) {
 206                                if (!memcmp(buf, *p, strlen(*p))) {
 207                                        buf += strlen(*p);
 208                                        break;
 209                                }
 210                                p++;
 211                        }
 212                }
 213                fmt++;
 214        } while (*buf && *fmt);
 215        printf("left: %s\n", buf);
 216        return mktime(&tm);                             
 217}
 218
 219static int convert_date_line(char *dst, void **buf, unsigned long *sp)
 220{
 221        unsigned long size = *sp;
 222        char *line = *buf;
 223        char *next = strchr(line, '\n');
 224        char *date = strchr(line, '>');
 225        int len;
 226
 227        if (!next || !date)
 228                die("missing or bad author/committer line %s", line);
 229        next++; date += 2;
 230
 231        *buf = next;
 232        *sp = size - (next - line);
 233
 234        len = date - line;
 235        memcpy(dst, line, len);
 236        dst += len;
 237
 238        /* Is it already in new format? */
 239        if (isdigit(*date)) {
 240                int datelen = next - date;
 241                memcpy(dst, date, datelen);
 242                return len + datelen;
 243        }
 244
 245        /*
 246         * Hacky hacky: one of the sparse old-style commits does not have
 247         * any date at all, but we can fake it by using the committer date.
 248         */
 249        if (*date == '\n' && strchr(next, '>'))
 250                date = strchr(next, '>')+2;
 251
 252        return len + sprintf(dst, "%lu -0700\n", parse_oldstyle_date(date));
 253}
 254
 255static void convert_date(void *buffer, unsigned long size, unsigned char *result_sha1)
 256{
 257        char *new = xmalloc(size + 100);
 258        unsigned long newlen = 0;
 259        
 260        // "tree <sha1>\n"
 261        memcpy(new + newlen, buffer, 46);
 262        newlen += 46;
 263        buffer += 46;
 264        size -= 46;
 265
 266        // "parent <sha1>\n"
 267        while (!memcmp(buffer, "parent ", 7)) {
 268                memcpy(new + newlen, buffer, 48);
 269                newlen += 48;
 270                buffer += 48;
 271                size -= 48;
 272        }
 273
 274        // "author xyz <xyz> date"
 275        newlen += convert_date_line(new + newlen, &buffer, &size);
 276        // "committer xyz <xyz> date"
 277        newlen += convert_date_line(new + newlen, &buffer, &size);
 278
 279        // Rest
 280        memcpy(new + newlen, buffer, size);
 281        newlen += size;
 282
 283        write_sha1_file(new, newlen, "commit", result_sha1);
 284        free(new);      
 285}
 286
 287static void convert_commit(void *buffer, unsigned long size, unsigned char *result_sha1)
 288{
 289        void *orig_buffer = buffer;
 290        unsigned long orig_size = size;
 291
 292        convert_ascii_sha1(buffer+5);
 293        buffer += 46;    /* "tree " + "hex sha1" + "\n" */
 294        while (!memcmp(buffer, "parent ", 7)) {
 295                convert_ascii_sha1(buffer+7);
 296                buffer += 48;
 297        }
 298        convert_date(orig_buffer, orig_size, result_sha1);
 299}
 300
 301static struct entry * convert_entry(unsigned char *sha1)
 302{
 303        struct entry *entry = lookup_entry(sha1);
 304        char type[20];
 305        void *buffer, *data;
 306        unsigned long size;
 307
 308        if (entry->converted)
 309                return entry;
 310        data = read_sha1_file(sha1, type, &size);
 311        if (!data)
 312                die("unable to read object %s", sha1_to_hex(sha1));
 313
 314        buffer = xmalloc(size);
 315        memcpy(buffer, data, size);
 316        
 317        if (!strcmp(type, "blob")) {
 318                write_sha1_file(buffer, size, "blob", entry->new_sha1);
 319        } else if (!strcmp(type, "tree"))
 320                convert_tree(buffer, size, entry->new_sha1);
 321        else if (!strcmp(type, "commit"))
 322                convert_commit(buffer, size, entry->new_sha1);
 323        else
 324                die("unknown object type '%s' in %s", type, sha1_to_hex(sha1));
 325        entry->converted = 1;
 326        free(buffer);
 327        return entry;
 328}
 329
 330int main(int argc, char **argv)
 331{
 332        unsigned char sha1[20];
 333        struct entry *entry;
 334
 335        if (argc != 2 || get_sha1(argv[1], sha1))
 336                usage("git-convert-cache <sha1>");
 337
 338        entry = convert_entry(sha1);
 339        printf("new sha1: %s\n", sha1_to_hex(entry->new_sha1));
 340        return 0;
 341}