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 struct object **objs;
   9 static int nr_objs;
  10 int obj_allocs;
  11
  12 const char *type_names[] = {
  13         "none", "blob", "tree", "commit", "bad"
  14 };
  15
  16 static int hashtable_index(const unsigned char *sha1)
  17 {
  18         unsigned int i;
  19         memcpy(&i, sha1, sizeof(unsigned int));
  20         return (int)(i % obj_allocs);
  21 }
  22
  23 static int find_object(const unsigned char *sha1)
  24 {
  25         int i;
  26
  27         if (!objs)
  28                 return -1;
  29
  30         i = hashtable_index(sha1);
  31         while (objs[i]) {
  32                 if (memcmp(sha1, objs[i]->sha1, 20) == 0)
  33                         return i;
  34                 i++;
  35                 if (i == obj_allocs)
  36                         i = 0;
  37         }
  38         return -1 - i;
  39 }
  40
  41 struct object *lookup_object(const unsigned char *sha1)
  42 {
  43         int pos = find_object(sha1);
  44         if (pos >= 0)
  45                 return objs[pos];
  46         return NULL;
  47 }
  48
  49 void created_object(const unsigned char *sha1, struct object *obj)
  50 {
  51         int pos;
  52
  53         obj->parsed = 0;
  54         memcpy(obj->sha1, sha1, 20);
  55         obj->type = TYPE_NONE;
  56         obj->used = 0;
  57
  58         if (obj_allocs - 1 <= nr_objs * 2) {
  59                 int i, count = obj_allocs;
  60                 obj_allocs = (obj_allocs < 32 ? 32 : 2 * obj_allocs);
  61                 objs = xrealloc(objs, obj_allocs * sizeof(struct object *));
  62                 memset(objs + count, 0, (obj_allocs - count)
  63                                 * sizeof(struct object *));
  64                 for (i = 0; i < obj_allocs; i++)
  65                         if (objs[i]) {
  66                                 int j = find_object(objs[i]->sha1);
  67                                 if (j != i) {
  68                                         j = -1 - j;
  69                                         objs[j] = objs[i];
  70                                         objs[i] = NULL;
  71                                 }
  72                         }
  73         }
  74
  75         pos = find_object(sha1);
  76         if (pos >= 0)
  77                 die("Inserting %s twice\n", sha1_to_hex(sha1));
  78         pos = -pos-1;
  79
  80         objs[pos] = obj;
  81         nr_objs++;
  82 }
  83
  84 struct object *lookup_object_type(const unsigned char *sha1, const char *type)
  85 {
  86         if (!type) {
  87                 return lookup_unknown_object(sha1);
  88         } else if (!strcmp(type, blob_type)) {
  89                 return &lookup_blob(sha1)->object;
  90         } else if (!strcmp(type, tree_type)) {
  91                 return &lookup_tree(sha1)->object;
  92         } else if (!strcmp(type, commit_type)) {
  93                 return &lookup_commit(sha1)->object;
  94         } else if (!strcmp(type, tag_type)) {
  95                 return &lookup_tag(sha1)->object;
  96         } else {
  97                 error("Unknown type %s", type);
  98                 return NULL;
  99         }
 100 }
 101
 102 union any_object {
 103         struct object object;
 104         struct commit commit;
 105         struct tree tree;
 106         struct blob blob;
 107         struct tag tag;
 108 };
 109
 110 struct object *lookup_unknown_object(const unsigned char *sha1)
 111 {
 112         struct object *obj = lookup_object(sha1);
 113         if (!obj) {
 114                 union any_object *ret = xcalloc(1, sizeof(*ret));
 115                 created_object(sha1, &ret->object);
 116                 ret->object.type = TYPE_NONE;
 117                 return &ret->object;
 118         }
 119         return obj;
 120 }
 121
 122 struct object *parse_object(const unsigned char *sha1)
 123 {
 124         unsigned long size;
 125         char type[20];
 126         void *buffer = read_sha1_file(sha1, type, &size);
 127         if (buffer) {
 128                 struct object *obj;
 129                 if (check_sha1_signature(sha1, buffer, size, type) < 0)
 130                         printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
 131                 if (!strcmp(type, blob_type)) {
 132                         struct blob *blob = lookup_blob(sha1);
 133                         parse_blob_buffer(blob, buffer, size);
 134                         obj = &blob->object;
 135                 } else if (!strcmp(type, tree_type)) {
 136                         struct tree *tree = lookup_tree(sha1);
 137                         obj = &tree->object;
 138                         if (!tree->object.parsed) {
 139                                 parse_tree_buffer(tree, buffer, size);
 140                                 buffer = NULL;
 141                         }
 142                 } else if (!strcmp(type, commit_type)) {
 143                         struct commit *commit = lookup_commit(sha1);
 144                         parse_commit_buffer(commit, buffer, size);
 145                         if (!commit->buffer) {
 146                                 commit->buffer = buffer;
 147                                 buffer = NULL;
 148                         }
 149                         obj = &commit->object;
 150                 } else if (!strcmp(type, tag_type)) {
 151                         struct tag *tag = lookup_tag(sha1);
 152                         parse_tag_buffer(tag, buffer, size);
 153                         obj = &tag->object;
 154                 } else {
 155                         obj = NULL;
 156                 }
 157                 free(buffer);
 158                 return obj;
 159         }
 160         return NULL;
 161 }
 162
 163 struct object_list *object_list_insert(struct object *item,
 164                                        struct object_list **list_p)
 165 {
 166         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 167         new_list->item = item;
 168         new_list->next = *list_p;
 169         *list_p = new_list;
 170         return new_list;
 171 }
 172
 173 void object_list_append(struct object *item,
 174                         struct object_list **list_p)
 175 {
 176         while (*list_p) {
 177                 list_p = &((*list_p)->next);
 178         }
 179         *list_p = xmalloc(sizeof(struct object_list));
 180         (*list_p)->next = NULL;
 181         (*list_p)->item = item;
 182 }
 183
 184 unsigned object_list_length(struct object_list *list)
 185 {
 186         unsigned ret = 0;
 187         while (list) {
 188                 list = list->next;
 189                 ret++;
 190         }
 191         return ret;
 192 }
 193
 194 int object_list_contains(struct object_list *list, struct object *obj)
 195 {
 196         while (list) {
 197                 if (list->item == obj)
 198                         return 1;
 199                 list = list->next;
 200         }
 201         return 0;
 202 }