git/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 *create_object(const unsigned char *sha1, int type, void *o)
 109 {
 110         struct object *obj = o;
 111
 112         obj->parsed = 0;
 113         obj->used = 0;
 114         obj->type = type;
 115         obj->flags = 0;
 116         hashcpy(obj->sha1, sha1);
 117
 118         if (obj_hash_size - 1 <= nr_objs * 2)
 119                 grow_object_hash();
 120
 121         insert_obj_hash(obj, obj_hash, obj_hash_size);
 122         nr_objs++;
 123         return obj;
 124 }
 125
 126 struct object *lookup_unknown_object(const unsigned char *sha1)
 127 {
 128         struct object *obj = lookup_object(sha1);
 129         if (!obj)
 130                 obj = create_object(sha1, OBJ_NONE, alloc_object_node());
 131         return obj;
 132 }
 133
 134 struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p)
 135 {
 136         struct object *obj;
 137         int eaten = 0;
 138
 139         if (type == OBJ_BLOB) {
 140                 struct blob *blob = lookup_blob(sha1);
 141                 parse_blob_buffer(blob, buffer, size);
 142                 obj = &blob->object;
 143         } else if (type == OBJ_TREE) {
 144                 struct tree *tree = lookup_tree(sha1);
 145                 obj = &tree->object;
 146                 if (!tree->object.parsed) {
 147                         parse_tree_buffer(tree, buffer, size);
 148                         eaten = 1;
 149                 }
 150         } else if (type == OBJ_COMMIT) {
 151                 struct commit *commit = lookup_commit(sha1);
 152                 parse_commit_buffer(commit, buffer, size);
 153                 if (!commit->buffer) {
 154                         commit->buffer = buffer;
 155                         eaten = 1;
 156                 }
 157                 obj = &commit->object;
 158         } else if (type == OBJ_TAG) {
 159                 struct tag *tag = lookup_tag(sha1);
 160                 parse_tag_buffer(tag, buffer, size);
 161                 obj = &tag->object;
 162         } else {
 163                 warning("object %s has unknown type id %d\n", sha1_to_hex(sha1), type);
 164                 obj = NULL;
 165         }
 166         if (obj && obj->type == OBJ_NONE)
 167                 obj->type = type;
 168         *eaten_p = eaten;
 169         return obj;
 170 }
 171
 172 struct object *parse_object(const unsigned char *sha1)
 173 {
 174         unsigned long size;
 175         enum object_type type;
 176         int eaten;
 177         void *buffer = read_sha1_file(sha1, &type, &size);
 178
 179         if (buffer) {
 180                 struct object *obj;
 181                 if (check_sha1_signature(sha1, buffer, size, typename(type)) < 0) {
 182                         free(buffer);
 183                         error("sha1 mismatch %s\n", sha1_to_hex(sha1));
 184                         return NULL;
 185                 }
 186
 187                 obj = parse_object_buffer(sha1, type, size, buffer, &eaten);
 188                 if (!eaten)
 189                         free(buffer);
 190                 return obj;
 191         }
 192         return NULL;
 193 }
 194
 195 struct object_list *object_list_insert(struct object *item,
 196                                        struct object_list **list_p)
 197 {
 198         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 199         new_list->item = item;
 200         new_list->next = *list_p;
 201         *list_p = new_list;
 202         return new_list;
 203 }
 204
 205 void object_list_append(struct object *item,
 206                         struct object_list **list_p)
 207 {
 208         while (*list_p) {
 209                 list_p = &((*list_p)->next);
 210         }
 211         *list_p = xmalloc(sizeof(struct object_list));
 212         (*list_p)->next = NULL;
 213         (*list_p)->item = item;
 214 }
 215
 216 unsigned object_list_length(struct object_list *list)
 217 {
 218         unsigned ret = 0;
 219         while (list) {
 220                 list = list->next;
 221                 ret++;
 222         }
 223         return ret;
 224 }
 225
 226 int object_list_contains(struct object_list *list, struct object *obj)
 227 {
 228         while (list) {
 229                 if (list->item == obj)
 230                         return 1;
 231                 list = list->next;
 232         }
 233         return 0;
 234 }
 235
 236 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 237 {
 238         add_object_array_with_mode(obj, name, array, S_IFINVALID);
 239 }
 240
 241 void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode)
 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         objects[nr].mode = mode;
 256         array->nr = ++nr;
 257 }