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