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 struct object *lookup_object_type(const unsigned char *sha1, const char *type)
 124 {
 125         if (!type) {
 126                 return lookup_unknown_object(sha1);
 127         } else if (!strcmp(type, blob_type)) {
 128                 return &lookup_blob(sha1)->object;
 129         } else if (!strcmp(type, tree_type)) {
 130                 return &lookup_tree(sha1)->object;
 131         } else if (!strcmp(type, commit_type)) {
 132                 return &lookup_commit(sha1)->object;
 133         } else if (!strcmp(type, tag_type)) {
 134                 return &lookup_tag(sha1)->object;
 135         } else {
 136                 error("Unknown type %s", type);
 137                 return NULL;
 138         }
 139 }
 140
 141 union any_object {
 142         struct object object;
 143         struct commit commit;
 144         struct tree tree;
 145         struct blob blob;
 146         struct tag tag;
 147 };
 148
 149 struct object *lookup_unknown_object(const unsigned char *sha1)
 150 {
 151         struct object *obj = lookup_object(sha1);
 152         if (!obj) {
 153                 union any_object *ret = xcalloc(1, sizeof(*ret));
 154                 created_object(sha1, &ret->object);
 155                 ret->object.type = OBJ_NONE;
 156                 return &ret->object;
 157         }
 158         return obj;
 159 }
 160
 161 struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
 162 {
 163         struct object *obj;
 164         int eaten = 0;
 165
 166         if (type == OBJ_BLOB) {
 167                 struct blob *blob = lookup_blob(sha1);
 168                 parse_blob_buffer(blob, buffer, size);
 169                 obj = &blob->object;
 170         } else if (type == OBJ_TREE) {
 171                 struct tree *tree = lookup_tree(sha1);
 172                 obj = &tree->object;
 173                 if (!tree->object.parsed) {
 174                         parse_tree_buffer(tree, buffer, size);
 175                         eaten = 1;
 176                 }
 177         } else if (type == OBJ_COMMIT) {
 178                 struct commit *commit = lookup_commit(sha1);
 179                 parse_commit_buffer(commit, buffer, size);
 180                 if (!commit->buffer) {
 181                         commit->buffer = buffer;
 182                         eaten = 1;
 183                 }
 184                 obj = &commit->object;
 185         } else if (type == OBJ_TAG) {
 186                 struct tag *tag = lookup_tag(sha1);
 187                 parse_tag_buffer(tag, buffer, size);
 188                 obj = &tag->object;
 189         } else {
 190                 obj = NULL;
 191         }
 192         *eaten_p = eaten;
 193         return obj;
 194 }
 195
 196 struct object *parse_object(const unsigned char *sha1)
 197 {
 198         unsigned long size;
 199         enum object_type type;
 200         int eaten;
 201         void *buffer = read_sha1_file(sha1, &type, &size);
 202
 203         if (buffer) {
 204                 struct object *obj;
 205                 if (check_sha1_signature(sha1, buffer, size, typename(type)) < 0)
 206                         printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
 207
 208                 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
 209                 if (!eaten)
 210                         free(buffer);
 211                 return obj;
 212         }
 213         return NULL;
 214 }
 215
 216 struct object_list *object_list_insert(struct object *item,
 217                                        struct object_list **list_p)
 218 {
 219         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 220         new_list->item = item;
 221         new_list->next = *list_p;
 222         *list_p = new_list;
 223         return new_list;
 224 }
 225
 226 void object_list_append(struct object *item,
 227                         struct object_list **list_p)
 228 {
 229         while (*list_p) {
 230                 list_p = &((*list_p)->next);
 231         }
 232         *list_p = xmalloc(sizeof(struct object_list));
 233         (*list_p)->next = NULL;
 234         (*list_p)->item = item;
 235 }
 236
 237 unsigned object_list_length(struct object_list *list)
 238 {
 239         unsigned ret = 0;
 240         while (list) {
 241                 list = list->next;
 242                 ret++;
 243         }
 244         return ret;
 245 }
 246
 247 int object_list_contains(struct object_list *list, struct object *obj)
 248 {
 249         while (list) {
 250                 if (list->item == obj)
 251                         return 1;
 252                 list = list->next;
 253         }
 254         return 0;
 255 }
 256
 257 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 258 {
 259         unsigned nr = array->nr;
 260         unsigned alloc = array->alloc;
 261         struct object_array_entry *objects = array->objects;
 262
 263         if (nr >= alloc) {
 264                 alloc = (alloc + 32) * 2;
 265                 objects = xrealloc(objects, alloc * sizeof(*objects));
 266                 array->alloc = alloc;
 267                 array->objects = objects;
 268         }
 269         objects[nr].item = obj;
 270         objects[nr].name = name;
 271         array->nr = ++nr;
 272 }