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