object.c

   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
   8 static struct object **obj_hash;
   9 static int nr_objs, obj_hash_size;
  10
  11 unsigned int get_max_object_index(void)
  12 {
  13         return obj_hash_size;
  14 }
  15
  16 struct object *get_indexed_object(unsigned int idx)
  17 {
  18         return obj_hash[idx];
  19 }
  20
  21 static 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
  29 const 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
  36 int type_from_string(const char *str)
  37 {
  38         int i;
  39
  40         for (i = 1; i < ARRAY_SIZE(object_type_strings); i++)
  41                 if (!strcmp(str, object_type_strings[i]))
  42                         return i;
  43         die("invalid object type \"%s\"", str);
  44 }
  45
  46 static unsigned int hash_obj(struct object *obj, unsigned int n)
  47 {
  48         unsigned int hash;
  49         memcpy(&hash, obj->sha1, sizeof(unsigned int));
  50         return hash % n;
  51 }
  52
  53 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
  54 {
  55         unsigned int j = hash_obj(obj, size);
  56
  57         while (hash[j]) {
  58                 j++;
  59                 if (j >= size)
  60                         j = 0;
  61         }
  62         hash[j] = obj;
  63 }
  64
  65 static unsigned int hashtable_index(const unsigned char *sha1)
  66 {
  67         unsigned int i;
  68         memcpy(&i, sha1, sizeof(unsigned int));
  69         return i % obj_hash_size;
  70 }
  71
  72 struct object *lookup_object(const unsigned char *sha1)
  73 {
  74         unsigned int i;
  75         struct object *obj;
  76
  77         if (!obj_hash)
  78                 return NULL;
  79
  80         i = hashtable_index(sha1);
  81         while ((obj = obj_hash[i]) != NULL) {
  82                 if (!hashcmp(sha1, obj->sha1))
  83                         break;
  84                 i++;
  85                 if (i == obj_hash_size)
  86                         i = 0;
  87         }
  88         return obj;
  89 }
  90
  91 static void grow_object_hash(void)
  92 {
  93         int i;
  94         int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
  95         struct object **new_hash;
  96
  97         new_hash = xcalloc(new_hash_size, sizeof(struct object *));
  98         for (i = 0; i < obj_hash_size; i++) {
  99                 struct object *obj = obj_hash[i];
 100                 if (!obj)
 101                         continue;
 102                 insert_obj_hash(obj, new_hash, new_hash_size);
 103         }
 104         free(obj_hash);
 105         obj_hash = new_hash;
 106         obj_hash_size = new_hash_size;
 107 }
 108
 109 void *create_object(const unsigned char *sha1, int type, void *o)
 110 {
 111         struct object *obj = o;
 112
 113         obj->parsed = 0;
 114         obj->used = 0;
 115         obj->type = type;
 116         obj->flags = 0;
 117         hashcpy(obj->sha1, sha1);
 118
 119         if (obj_hash_size - 1 <= nr_objs * 2)
 120                 grow_object_hash();
 121
 122         insert_obj_hash(obj, obj_hash, obj_hash_size);
 123         nr_objs++;
 124         return obj;
 125 }
 126
 127 struct object *lookup_unknown_object(const unsigned char *sha1)
 128 {
 129         struct object *obj = lookup_object(sha1);
 130         if (!obj)
 131                 obj = create_object(sha1, OBJ_NONE, alloc_object_node());
 132         return obj;
 133 }
 134
 135 struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
 136 {
 137         struct object *obj;
 138         int eaten = 0;
 139
 140         obj = NULL;
 141         if (type == OBJ_BLOB) {
 142                 struct blob *blob = lookup_blob(sha1);
 143                 if (blob) {
 144                         if (parse_blob_buffer(blob, buffer, size))
 145                                 return NULL;
 146                         obj = &blob->object;
 147                 }
 148         } else if (type == OBJ_TREE) {
 149                 struct tree *tree = lookup_tree(sha1);
 150                 if (tree) {
 151                         obj = &tree->object;
 152                         if (!tree->buffer)
 153                                 tree->object.parsed = 0;
 154                         if (!tree->object.parsed) {
 155                                 if (parse_tree_buffer(tree, buffer, size))
 156                                         return NULL;
 157                                 eaten = 1;
 158                         }
 159                 }
 160         } else if (type == OBJ_COMMIT) {
 161                 struct commit *commit = lookup_commit(sha1);
 162                 if (commit) {
 163                         if (parse_commit_buffer(commit, buffer, size))
 164                                 return NULL;
 165                         if (!commit->buffer) {
 166                                 commit->buffer = buffer;
 167                                 eaten = 1;
 168                         }
 169                         obj = &commit->object;
 170                 }
 171         } else if (type == OBJ_TAG) {
 172                 struct tag *tag = lookup_tag(sha1);
 173                 if (tag) {
 174                         if (parse_tag_buffer(tag, buffer, size))
 175                                return NULL;
 176                         obj = &tag->object;
 177                 }
 178         } else {
 179                 warning("object %s has unknown type id %d\n", sha1_to_hex(sha1), type);
 180                 obj = NULL;
 181         }
 182         if (obj && obj->type == OBJ_NONE)
 183                 obj->type = type;
 184         *eaten_p = eaten;
 185         return obj;
 186 }
 187
 188 struct object *parse_object(const unsigned char *sha1)
 189 {
 190         unsigned long size;
 191         enum object_type type;
 192         int eaten;
 193         const unsigned char *repl = lookup_replace_object(sha1);
 194         void *buffer;
 195         struct object *obj;
 196
 197         obj = lookup_object(sha1);
 198         if (obj && obj->parsed)
 199                 return obj;
 200
 201         buffer = read_sha1_file(sha1, &type, &size);
 202         if (buffer) {
 203                 if (check_sha1_signature(repl, buffer, size, typename(type)) < 0) {
 204                         free(buffer);
 205                         error("sha1 mismatch %s\n", sha1_to_hex(repl));
 206                         return NULL;
 207                 }
 208
 209                 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
 210                 if (!eaten)
 211                         free(buffer);
 212                 return obj;
 213         }
 214         return NULL;
 215 }
 216
 217 struct object_list *object_list_insert(struct object *item,
 218                                        struct object_list **list_p)
 219 {
 220         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 221         new_list->item = item;
 222         new_list->next = *list_p;
 223         *list_p = new_list;
 224         return new_list;
 225 }
 226
 227 int object_list_contains(struct object_list *list, struct object *obj)
 228 {
 229         while (list) {
 230                 if (list->item == obj)
 231                         return 1;
 232                 list = list->next;
 233         }
 234         return 0;
 235 }
 236
 237 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 238 {
 239         add_object_array_with_mode(obj, name, array, S_IFINVALID);
 240 }
 241
 242 void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode)
 243 {
 244         unsigned nr = array->nr;
 245         unsigned alloc = array->alloc;
 246         struct object_array_entry *objects = array->objects;
 247
 248         if (nr >= alloc) {
 249                 alloc = (alloc + 32) * 2;
 250                 objects = xrealloc(objects, alloc * sizeof(*objects));
 251                 array->alloc = alloc;
 252                 array->objects = objects;
 253         }
 254         objects[nr].item = obj;
 255         objects[nr].name = name;
 256         objects[nr].mode = mode;
 257         array->nr = ++nr;
 258 }
 259
 260 void object_array_remove_duplicates(struct object_array *array)
 261 {
 262         unsigned int ref, src, dst;
 263         struct object_array_entry *objects = array->objects;
 264
 265         for (ref = 0; ref + 1 < array->nr; ref++) {
 266                 for (src = ref + 1, dst = src;
 267                      src < array->nr;
 268                      src++) {
 269                         if (!strcmp(objects[ref].name, objects[src].name))
 270                                 continue;
 271                         if (src != dst)
 272                                 objects[dst] = objects[src];
 273                         dst++;
 274                 }
 275                 array->nr = dst;
 276         }
 277 }