object.con commit Merge branch 'jk/delta-chain-limit' into maint (252ef8f)
   1#include "cache.h"
   2#include "object.h"
   3#include "blob.h"
   4#include "tree.h"
   5#include "commit.h"
   6#include "tag.h"
   7
   8static struct object **obj_hash;
   9static int nr_objs, obj_hash_size;
  10
  11unsigned int get_max_object_index(void)
  12{
  13        return obj_hash_size;
  14}
  15
  16struct object *get_indexed_object(unsigned int idx)
  17{
  18        return obj_hash[idx];
  19}
  20
  21static const char *object_type_strings[] = {
  22        NULL,           /* OBJ_NONE = 0 */
  23        "commit",       /* OBJ_COMMIT = 1 */
  24        "tree",         /* OBJ_TREE = 2 */
  25        "blob",         /* OBJ_BLOB = 3 */
  26        "tag",          /* OBJ_TAG = 4 */
  27};
  28
  29const char *typename(unsigned int type)
  30{
  31        if (type >= ARRAY_SIZE(object_type_strings))
  32                return NULL;
  33        return object_type_strings[type];
  34}
  35
  36int type_from_string_gently(const char *str, ssize_t len, int gentle)
  37{
  38        int i;
  39
  40        if (len < 0)
  41                len = strlen(str);
  42
  43        for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  44                if (!strncmp(str, object_type_strings[i], len) &&
  45                    object_type_strings[i][len] == '\0')
  46                        return i;
  47
  48        if (gentle)
  49                return -1;
  50
  51        die("invalid object type \"%s\"", str);
  52}
  53
  54/*
  55 * Return a numerical hash value between 0 and n-1 for the object with
  56 * the specified sha1.  n must be a power of 2.  Please note that the
  57 * return value is *not* consistent across computer architectures.
  58 */
  59static unsigned int hash_obj(const unsigned char *sha1, unsigned int n)
  60{
  61        return sha1hash(sha1) & (n - 1);
  62}
  63
  64/*
  65 * Insert obj into the hash table hash, which has length size (which
  66 * must be a power of 2).  On collisions, simply overflow to the next
  67 * empty bucket.
  68 */
  69static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
  70{
  71        unsigned int j = hash_obj(obj->oid.hash, size);
  72
  73        while (hash[j]) {
  74                j++;
  75                if (j >= size)
  76                        j = 0;
  77        }
  78        hash[j] = obj;
  79}
  80
  81/*
  82 * Look up the record for the given sha1 in the hash map stored in
  83 * obj_hash.  Return NULL if it was not found.
  84 */
  85struct object *lookup_object(const unsigned char *sha1)
  86{
  87        unsigned int i, first;
  88        struct object *obj;
  89
  90        if (!obj_hash)
  91                return NULL;
  92
  93        first = i = hash_obj(sha1, obj_hash_size);
  94        while ((obj = obj_hash[i]) != NULL) {
  95                if (!hashcmp(sha1, obj->oid.hash))
  96                        break;
  97                i++;
  98                if (i == obj_hash_size)
  99                        i = 0;
 100        }
 101        if (obj && i != first) {
 102                /*
 103                 * Move object to where we started to look for it so
 104                 * that we do not need to walk the hash table the next
 105                 * time we look for it.
 106                 */
 107                SWAP(obj_hash[i], obj_hash[first]);
 108        }
 109        return obj;
 110}
 111
 112/*
 113 * Increase the size of the hash map stored in obj_hash to the next
 114 * power of 2 (but at least 32).  Copy the existing values to the new
 115 * hash map.
 116 */
 117static void grow_object_hash(void)
 118{
 119        int i;
 120        /*
 121         * Note that this size must always be power-of-2 to match hash_obj
 122         * above.
 123         */
 124        int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
 125        struct object **new_hash;
 126
 127        new_hash = xcalloc(new_hash_size, sizeof(struct object *));
 128        for (i = 0; i < obj_hash_size; i++) {
 129                struct object *obj = obj_hash[i];
 130                if (!obj)
 131                        continue;
 132                insert_obj_hash(obj, new_hash, new_hash_size);
 133        }
 134        free(obj_hash);
 135        obj_hash = new_hash;
 136        obj_hash_size = new_hash_size;
 137}
 138
 139void *create_object(const unsigned char *sha1, void *o)
 140{
 141        struct object *obj = o;
 142
 143        obj->parsed = 0;
 144        obj->used = 0;
 145        obj->flags = 0;
 146        hashcpy(obj->oid.hash, sha1);
 147
 148        if (obj_hash_size - 1 <= nr_objs * 2)
 149                grow_object_hash();
 150
 151        insert_obj_hash(obj, obj_hash, obj_hash_size);
 152        nr_objs++;
 153        return obj;
 154}
 155
 156void *object_as_type(struct object *obj, enum object_type type, int quiet)
 157{
 158        if (obj->type == type)
 159                return obj;
 160        else if (obj->type == OBJ_NONE) {
 161                if (type == OBJ_COMMIT)
 162                        ((struct commit *)obj)->index = alloc_commit_index();
 163                obj->type = type;
 164                return obj;
 165        }
 166        else {
 167                if (!quiet)
 168                        error("object %s is a %s, not a %s",
 169                              oid_to_hex(&obj->oid),
 170                              typename(obj->type), typename(type));
 171                return NULL;
 172        }
 173}
 174
 175struct object *lookup_unknown_object(const unsigned char *sha1)
 176{
 177        struct object *obj = lookup_object(sha1);
 178        if (!obj)
 179                obj = create_object(sha1, alloc_object_node());
 180        return obj;
 181}
 182
 183struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
 184{
 185        struct object *obj;
 186        *eaten_p = 0;
 187
 188        obj = NULL;
 189        if (type == OBJ_BLOB) {
 190                struct blob *blob = lookup_blob(sha1);
 191                if (blob) {
 192                        if (parse_blob_buffer(blob, buffer, size))
 193                                return NULL;
 194                        obj = &blob->object;
 195                }
 196        } else if (type == OBJ_TREE) {
 197                struct tree *tree = lookup_tree(sha1);
 198                if (tree) {
 199                        obj = &tree->object;
 200                        if (!tree->buffer)
 201                                tree->object.parsed = 0;
 202                        if (!tree->object.parsed) {
 203                                if (parse_tree_buffer(tree, buffer, size))
 204                                        return NULL;
 205                                *eaten_p = 1;
 206                        }
 207                }
 208        } else if (type == OBJ_COMMIT) {
 209                struct commit *commit = lookup_commit(sha1);
 210                if (commit) {
 211                        if (parse_commit_buffer(commit, buffer, size))
 212                                return NULL;
 213                        if (!get_cached_commit_buffer(commit, NULL)) {
 214                                set_commit_buffer(commit, buffer, size);
 215                                *eaten_p = 1;
 216                        }
 217                        obj = &commit->object;
 218                }
 219        } else if (type == OBJ_TAG) {
 220                struct tag *tag = lookup_tag(sha1);
 221                if (tag) {
 222                        if (parse_tag_buffer(tag, buffer, size))
 223                               return NULL;
 224                        obj = &tag->object;
 225                }
 226        } else {
 227                warning("object %s has unknown type id %d", sha1_to_hex(sha1), type);
 228                obj = NULL;
 229        }
 230        return obj;
 231}
 232
 233struct object *parse_object_or_die(const unsigned char *sha1,
 234                                   const char *name)
 235{
 236        struct object *o = parse_object(sha1);
 237        if (o)
 238                return o;
 239
 240        die(_("unable to parse object: %s"), name ? name : sha1_to_hex(sha1));
 241}
 242
 243struct object *parse_object(const unsigned char *sha1)
 244{
 245        unsigned long size;
 246        enum object_type type;
 247        int eaten;
 248        const unsigned char *repl = lookup_replace_object(sha1);
 249        void *buffer;
 250        struct object *obj;
 251
 252        obj = lookup_object(sha1);
 253        if (obj && obj->parsed)
 254                return obj;
 255
 256        if ((obj && obj->type == OBJ_BLOB) ||
 257            (!obj && has_sha1_file(sha1) &&
 258             sha1_object_info(sha1, NULL) == OBJ_BLOB)) {
 259                if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
 260                        error("sha1 mismatch %s", sha1_to_hex(repl));
 261                        return NULL;
 262                }
 263                parse_blob_buffer(lookup_blob(sha1), NULL, 0);
 264                return lookup_object(sha1);
 265        }
 266
 267        buffer = read_sha1_file(sha1, &type, &size);
 268        if (buffer) {
 269                if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
 270                        free(buffer);
 271                        error("sha1 mismatch %s", sha1_to_hex(repl));
 272                        return NULL;
 273                }
 274
 275                obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
 276                if (!eaten)
 277                        free(buffer);
 278                return obj;
 279        }
 280        return NULL;
 281}
 282
 283struct object_list *object_list_insert(struct object *item,
 284                                       struct object_list **list_p)
 285{
 286        struct object_list *new_list = xmalloc(sizeof(struct object_list));
 287        new_list->item = item;
 288        new_list->next = *list_p;
 289        *list_p = new_list;
 290        return new_list;
 291}
 292
 293int object_list_contains(struct object_list *list, struct object *obj)
 294{
 295        while (list) {
 296                if (list->item == obj)
 297                        return 1;
 298                list = list->next;
 299        }
 300        return 0;
 301}
 302
 303/*
 304 * A zero-length string to which object_array_entry::name can be
 305 * initialized without requiring a malloc/free.
 306 */
 307static char object_array_slopbuf[1];
 308
 309void add_object_array_with_path(struct object *obj, const char *name,
 310                                struct object_array *array,
 311                                unsigned mode, const char *path)
 312{
 313        unsigned nr = array->nr;
 314        unsigned alloc = array->alloc;
 315        struct object_array_entry *objects = array->objects;
 316        struct object_array_entry *entry;
 317
 318        if (nr >= alloc) {
 319                alloc = (alloc + 32) * 2;
 320                REALLOC_ARRAY(objects, alloc);
 321                array->alloc = alloc;
 322                array->objects = objects;
 323        }
 324        entry = &objects[nr];
 325        entry->item = obj;
 326        if (!name)
 327                entry->name = NULL;
 328        else if (!*name)
 329                /* Use our own empty string instead of allocating one: */
 330                entry->name = object_array_slopbuf;
 331        else
 332                entry->name = xstrdup(name);
 333        entry->mode = mode;
 334        if (path)
 335                entry->path = xstrdup(path);
 336        else
 337                entry->path = NULL;
 338        array->nr = ++nr;
 339}
 340
 341void add_object_array(struct object *obj, const char *name, struct object_array *array)
 342{
 343        add_object_array_with_path(obj, name, array, S_IFINVALID, NULL);
 344}
 345
 346/*
 347 * Free all memory associated with an entry; the result is
 348 * in an unspecified state and should not be examined.
 349 */
 350static void object_array_release_entry(struct object_array_entry *ent)
 351{
 352        if (ent->name != object_array_slopbuf)
 353                free(ent->name);
 354        free(ent->path);
 355}
 356
 357void object_array_filter(struct object_array *array,
 358                         object_array_each_func_t want, void *cb_data)
 359{
 360        unsigned nr = array->nr, src, dst;
 361        struct object_array_entry *objects = array->objects;
 362
 363        for (src = dst = 0; src < nr; src++) {
 364                if (want(&objects[src], cb_data)) {
 365                        if (src != dst)
 366                                objects[dst] = objects[src];
 367                        dst++;
 368                } else {
 369                        object_array_release_entry(&objects[src]);
 370                }
 371        }
 372        array->nr = dst;
 373}
 374
 375void object_array_clear(struct object_array *array)
 376{
 377        int i;
 378        for (i = 0; i < array->nr; i++)
 379                object_array_release_entry(&array->objects[i]);
 380        free(array->objects);
 381        array->objects = NULL;
 382        array->nr = array->alloc = 0;
 383}
 384
 385/*
 386 * Return true iff array already contains an entry with name.
 387 */
 388static int contains_name(struct object_array *array, const char *name)
 389{
 390        unsigned nr = array->nr, i;
 391        struct object_array_entry *object = array->objects;
 392
 393        for (i = 0; i < nr; i++, object++)
 394                if (!strcmp(object->name, name))
 395                        return 1;
 396        return 0;
 397}
 398
 399void object_array_remove_duplicates(struct object_array *array)
 400{
 401        unsigned nr = array->nr, src;
 402        struct object_array_entry *objects = array->objects;
 403
 404        array->nr = 0;
 405        for (src = 0; src < nr; src++) {
 406                if (!contains_name(array, objects[src].name)) {
 407                        if (src != array->nr)
 408                                objects[array->nr] = objects[src];
 409                        array->nr++;
 410                } else {
 411                        object_array_release_entry(&objects[src]);
 412                }
 413        }
 414}
 415
 416void clear_object_flags(unsigned flags)
 417{
 418        int i;
 419
 420        for (i=0; i < obj_hash_size; i++) {
 421                struct object *obj = obj_hash[i];
 422                if (obj)
 423                        obj->flags &= ~flags;
 424        }
 425}