Andrew's git - gitweb.git/blob

e7014a064e1a1562b35b7c5c95fb0e9843a54ebd
   1#include "cache.h"
   2
   3#include <sys/types.h>
   4#include <dirent.h>
   5
   6/*
   7 * The low 16 bits of the "flags" field shows whether
   8 * a commit is part of the path to the root for that
   9 * parent.
  10 *
  11 * Bit 16 is an internal flag that we've seen the
  12 * definition for this rev, and not just seen it as
  13 * a parent target.
  14 */
  15#define MAX_COMMITS (16)
  16#define marked(rev)     ((rev)->flags & 0xffff)
  17#define SEEN 0x10000
  18#define USED 0x20000
  19#define REACHABLE 0x40000
  20
  21static int show_unreachable = 0;
  22static unsigned char head_sha1[20];
  23
  24struct parent {
  25        struct revision *parent;
  26        struct parent *next;
  27};
  28
  29struct revision {
  30        unsigned int flags;
  31        unsigned char sha1[20];
  32        unsigned long date;
  33        struct parent *parent;
  34};
  35
  36static struct revision **revs;
  37static int nr_revs, rev_allocs;
  38
  39static int find_rev(unsigned char *sha1)
  40{
  41        int first = 0, last = nr_revs;
  42
  43        while (first < last) {
  44                int next = (first + last) / 2;
  45                struct revision *rev = revs[next];
  46                int cmp;
  47
  48                cmp = memcmp(sha1, rev->sha1, 20);
  49                if (!cmp)
  50                        return next;
  51                if (cmp < 0) {
  52                        last = next;
  53                        continue;
  54                }
  55                first = next+1;
  56        }
  57        return -first-1;
  58}
  59
  60static struct revision *lookup_rev(unsigned char *sha1)
  61{
  62        int pos = find_rev(sha1);
  63        struct revision *n;
  64
  65        if (pos >= 0)
  66                return revs[pos];
  67        
  68        pos = -pos-1;
  69
  70        if (rev_allocs == nr_revs) {
  71                rev_allocs = alloc_nr(rev_allocs);
  72                revs = realloc(revs, rev_allocs * sizeof(struct revision *));
  73        }
  74        n = malloc(sizeof(struct revision));
  75
  76        n->flags = 0;
  77        memcpy(n->sha1, sha1, 20);
  78        n->parent = NULL;
  79
  80        /* Insert it into the right place */
  81        memmove(revs + pos + 1, revs + pos, (nr_revs - pos) * sizeof(struct revision *));
  82        revs[pos] = n;
  83        nr_revs++;
  84
  85        return n;
  86}
  87
  88static struct revision *add_relationship(struct revision *rev, unsigned char *needs)
  89{
  90        struct revision *parent_rev = lookup_rev(needs);
  91        struct parent **pp = &rev->parent, *p;
  92
  93        while ((p = *pp) != NULL) {
  94                if (p->parent == parent_rev)
  95                        return parent_rev;
  96                pp = &p->next;
  97        }
  98
  99        p = malloc(sizeof(*p));
 100        p->parent = parent_rev;
 101        p->next = NULL;
 102        *pp = p;
 103        return parent_rev;
 104}
 105
 106static void mark_reachable(struct revision *rev)
 107{
 108        struct parent *p = rev->parent;
 109
 110        /* If we've been here already, don't bother */
 111        if (rev->flags & REACHABLE)
 112                return;
 113        rev->flags |= REACHABLE | USED;
 114        while (p) {
 115                mark_reachable(p->parent);
 116                p = p->next;
 117        }
 118}
 119
 120static void check_connectivity(void)
 121{
 122        int i;
 123
 124        /* Look up all the requirements, warn about missing objects.. */
 125        for (i = 0; i < nr_revs; i++) {
 126                struct revision *rev = revs[i];
 127
 128                if (show_unreachable && !(rev->flags & REACHABLE)) {
 129                        printf("unreachable %s\n", sha1_to_hex(rev->sha1));
 130                        continue;
 131                }
 132
 133                switch (rev->flags & (SEEN | USED)) {
 134                case 0:
 135                        printf("bad %s\n", sha1_to_hex(rev->sha1));
 136                        break;
 137                case USED:
 138                        printf("missing %s\n", sha1_to_hex(rev->sha1));
 139                        break;
 140                case SEEN:
 141                        printf("dangling %s\n", sha1_to_hex(rev->sha1));
 142                        break;
 143                }
 144        }
 145}
 146
 147static void mark_needs_sha1(unsigned char *parent, const char * tag, unsigned char *child)
 148{
 149        struct revision * child_rev = add_relationship(lookup_rev(parent), child);
 150        child_rev->flags |= USED;
 151}
 152
 153static int mark_sha1_seen(unsigned char *sha1, char *tag)
 154{
 155        struct revision *rev = lookup_rev(sha1);
 156
 157        rev->flags |= SEEN;
 158        return 0;
 159}
 160
 161static int fsck_tree(unsigned char *sha1, void *data, unsigned long size)
 162{
 163        int warn_old_tree = 1;
 164
 165        while (size) {
 166                int len = 1+strlen(data);
 167                unsigned char *file_sha1 = data + len;
 168                char *path = strchr(data, ' ');
 169                unsigned int mode;
 170                if (size < len + 20 || !path || sscanf(data, "%o", &mode) != 1)
 171                        return -1;
 172
 173                /* Warn about trees that don't do the recursive thing.. */
 174                if (warn_old_tree && strchr(path, '/')) {
 175                        fprintf(stderr, "warning: fsck-cache: tree %s has full pathnames in it\n", sha1_to_hex(sha1));
 176                        warn_old_tree = 0;
 177                }
 178
 179                data += len + 20;
 180                size -= len + 20;
 181                mark_needs_sha1(sha1, S_ISDIR(mode) ? "tree" : "blob", file_sha1);
 182        }
 183        return 0;
 184}
 185
 186static int fsck_commit(unsigned char *sha1, void *data, unsigned long size)
 187{
 188        int parents;
 189        unsigned char tree_sha1[20];
 190        unsigned char parent_sha1[20];
 191
 192        if (memcmp(data, "tree ", 5))
 193                return -1;
 194        if (get_sha1_hex(data + 5, tree_sha1) < 0)
 195                return -1;
 196        mark_needs_sha1(sha1, "tree", tree_sha1);
 197        data += 5 + 40 + 1;     /* "tree " + <hex sha1> + '\n' */
 198        parents = 0;
 199        while (!memcmp(data, "parent ", 7)) {
 200                if (get_sha1_hex(data + 7, parent_sha1) < 0)
 201                        return -1;
 202                mark_needs_sha1(sha1, "commit", parent_sha1);
 203                data += 7 + 40 + 1;     /* "parent " + <hex sha1> + '\n' */
 204                parents++;
 205        }
 206        if (!parents)
 207                printf("root %s\n", sha1_to_hex(sha1));
 208        return 0;
 209}
 210
 211static int fsck_entry(unsigned char *sha1, char *tag, void *data, unsigned long size)
 212{
 213        if (!strcmp(tag, "blob")) {
 214                /* Nothing to check */;
 215        } else if (!strcmp(tag, "tree")) {
 216                if (fsck_tree(sha1, data, size) < 0)
 217                        return -1;
 218        } else if (!strcmp(tag, "commit")) {
 219                if (fsck_commit(sha1, data, size) < 0)
 220                        return -1;
 221        } else
 222                return -1;
 223        return mark_sha1_seen(sha1, tag);
 224}
 225
 226static int fsck_name(char *hex)
 227{
 228        unsigned char sha1[20];
 229        if (!get_sha1_hex(hex, sha1)) {
 230                unsigned long mapsize;
 231                void *map = map_sha1_file(sha1, &mapsize);
 232                if (map) {
 233                        char type[100];
 234                        unsigned long size;
 235                        void *buffer = NULL;
 236                        if (!check_sha1_signature(sha1, map, mapsize))
 237                                buffer = unpack_sha1_file(map, mapsize, type, &size);
 238                        munmap(map, mapsize);
 239                        if (buffer && !fsck_entry(sha1, type, buffer, size))
 240                                return 0;
 241                }
 242        }
 243        return -1;
 244}
 245
 246static int fsck_dir(int i, char *path)
 247{
 248        DIR *dir = opendir(path);
 249        struct dirent *de;
 250
 251        if (!dir) {
 252                return error("missing sha1 directory '%s'", path);
 253        }
 254
 255        while ((de = readdir(dir)) != NULL) {
 256                char name[100];
 257                int len = strlen(de->d_name);
 258
 259                switch (len) {
 260                case 2:
 261                        if (de->d_name[1] != '.')
 262                                break;
 263                case 1:
 264                        if (de->d_name[0] != '.')
 265                                break;
 266                        continue;
 267                case 38:
 268                        sprintf(name, "%02x", i);
 269                        memcpy(name+2, de->d_name, len+1);
 270                        if (!fsck_name(name))
 271                                continue;
 272                }
 273                fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
 274        }
 275        closedir(dir);
 276        return 0;
 277}
 278
 279int main(int argc, char **argv)
 280{
 281        int i, heads;
 282        char *sha1_dir;
 283
 284        sha1_dir = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
 285        for (i = 0; i < 256; i++) {
 286                static char dir[4096];
 287                sprintf(dir, "%s/%02x", sha1_dir, i);
 288                fsck_dir(i, dir);
 289        }
 290
 291        heads = 0;
 292        for (i = 1; i < argc; i++) {
 293                if (!strcmp(argv[i], "--unreachable")) {
 294                        show_unreachable = 1;
 295                        continue;
 296                }
 297                if (!get_sha1_hex(argv[i], head_sha1)) {
 298                        mark_reachable(lookup_rev(head_sha1));
 299                        heads++;
 300                        continue;
 301                }
 302                error("fsck-cache [[--unreachable] <head-sha1>*]");
 303        }
 304
 305        if (!heads) {
 306                if (show_unreachable) {
 307                        fprintf(stderr, "unable to do reachability without a head\n");
 308                        show_unreachable = 0; 
 309                }
 310                fprintf(stderr, "expect dangling commits - potential heads - due to lack of head information\n");
 311        }
 312
 313        check_connectivity();
 314        return 0;
 315}