object.c

   1 #include "object.h"
   2 #include "blob.h"
   3 #include "tree.h"
   4 #include "commit.h"
   5 #include "cache.h"
   6 #include "tag.h"
   7
   8 struct object **objs;
   9 int nr_objs;
  10 static int obj_allocs;
  11
  12 static int find_object(const unsigned char *sha1)
  13 {
  14         int first = 0, last = nr_objs;
  15
  16         while (first < last) {
  17                 int next = (first + last) / 2;
  18                 struct object *obj = objs[next];
  19                 int cmp;
  20
  21                 cmp = memcmp(sha1, obj->sha1, 20);
  22                 if (!cmp)
  23                         return next;
  24                 if (cmp < 0) {
  25                         last = next;
  26                         continue;
  27                 }
  28                 first = next+1;
  29         }
  30         return -first-1;
  31 }
  32
  33 struct object *lookup_object(const unsigned char *sha1)
  34 {
  35         int pos = find_object(sha1);
  36         if (pos >= 0)
  37                 return objs[pos];
  38         return NULL;
  39 }
  40
  41 void created_object(const unsigned char *sha1, struct object *obj)
  42 {
  43         int pos = find_object(sha1);
  44
  45         obj->parsed = 0;
  46         memcpy(obj->sha1, sha1, 20);
  47         obj->type = NULL;
  48         obj->refs = NULL;
  49         obj->used = 0;
  50
  51         if (pos >= 0)
  52                 die("Inserting %s twice\n", sha1_to_hex(sha1));
  53         pos = -pos-1;
  54
  55         if (obj_allocs == nr_objs) {
  56                 obj_allocs = alloc_nr(obj_allocs);
  57                 objs = xrealloc(objs, obj_allocs * sizeof(struct object *));
  58         }
  59
  60         /* Insert it into the right place */
  61         memmove(objs + pos + 1, objs + pos, (nr_objs - pos) *
  62                 sizeof(struct object *));
  63
  64         objs[pos] = obj;
  65         nr_objs++;
  66 }
  67
  68 void add_ref(struct object *refer, struct object *target)
  69 {
  70         struct object_list **pp = &refer->refs;
  71         struct object_list *p;
  72
  73         while ((p = *pp) != NULL) {
  74                 if (p->item == target)
  75                         return;
  76                 pp = &p->next;
  77         }
  78
  79         target->used = 1;
  80         p = xmalloc(sizeof(*p));
  81         p->item = target;
  82         p->next = NULL;
  83         *pp = p;
  84 }
  85
  86 void mark_reachable(struct object *obj, unsigned int mask)
  87 {
  88         struct object_list *p = obj->refs;
  89
  90         /* If we've been here already, don't bother */
  91         if (obj->flags & mask)
  92                 return;
  93         obj->flags |= mask;
  94         while (p) {
  95                 mark_reachable(p->item, mask);
  96                 p = p->next;
  97         }
  98 }
  99
 100 struct object *lookup_object_type(const unsigned char *sha1, const char *type)
 101 {
 102         if (!type) {
 103                 return lookup_unknown_object(sha1);
 104         } else if (!strcmp(type, blob_type)) {
 105                 return &lookup_blob(sha1)->object;
 106         } else if (!strcmp(type, tree_type)) {
 107                 return &lookup_tree(sha1)->object;
 108         } else if (!strcmp(type, commit_type)) {
 109                 return &lookup_commit(sha1)->object;
 110         } else if (!strcmp(type, tag_type)) {
 111                 return &lookup_tag(sha1)->object;
 112         } else {
 113                 error("Unknown type %s", type);
 114                 return NULL;
 115         }
 116 }
 117
 118 union any_object {
 119         struct object object;
 120         struct commit commit;
 121         struct tree tree;
 122         struct blob blob;
 123         struct tag tag;
 124 };
 125
 126 struct object *lookup_unknown_object(const unsigned char *sha1)
 127 {
 128         struct object *obj = lookup_object(sha1);
 129         if (!obj) {
 130                 union any_object *ret = xmalloc(sizeof(*ret));
 131                 memset(ret, 0, sizeof(*ret));
 132                 created_object(sha1, &ret->object);
 133                 ret->object.type = NULL;
 134                 return &ret->object;
 135         }
 136         return obj;
 137 }
 138
 139 struct object *parse_object(const unsigned char *sha1)
 140 {
 141         unsigned long size;
 142         char type[20];
 143         void *buffer = read_sha1_file(sha1, type, &size);
 144         if (buffer) {
 145                 struct object *obj;
 146                 if (check_sha1_signature(sha1, buffer, size, type) < 0)
 147                         printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
 148                 if (!strcmp(type, "blob")) {
 149                         struct blob *blob = lookup_blob(sha1);
 150                         parse_blob_buffer(blob, buffer, size);
 151                         obj = &blob->object;
 152                 } else if (!strcmp(type, "tree")) {
 153                         struct tree *tree = lookup_tree(sha1);
 154                         parse_tree_buffer(tree, buffer, size);
 155                         obj = &tree->object;
 156                 } else if (!strcmp(type, "commit")) {
 157                         struct commit *commit = lookup_commit(sha1);
 158                         parse_commit_buffer(commit, buffer, size);
 159                         if (!commit->buffer) {
 160                                 commit->buffer = buffer;
 161                                 buffer = NULL;
 162                         }
 163                         obj = &commit->object;
 164                 } else if (!strcmp(type, "tag")) {
 165                         struct tag *tag = lookup_tag(sha1);
 166                         parse_tag_buffer(tag, buffer, size);
 167                         obj = &tag->object;
 168                 } else {
 169                         obj = NULL;
 170                 }
 171                 free(buffer);
 172                 return obj;
 173         }
 174         return NULL;
 175 }
 176
 177 struct object_list *object_list_insert(struct object *item,
 178                                        struct object_list **list_p)
 179 {
 180         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 181         new_list->item = item;
 182         new_list->next = *list_p;
 183         *list_p = new_list;
 184         return new_list;
 185 }
 186
 187 unsigned object_list_length(struct object_list *list)
 188 {
 189         unsigned ret = 0;
 190         while (list) {
 191                 list = list->next;
 192                 ret++;
 193         }
 194         return ret;
 195 }
 196
 197 int object_list_contains(struct object_list *list, struct object *obj)
 198 {
 199         while (list) {
 200                 if (list->item == obj)
 201                         return 1;
 202                 list = list->next;
 203         }
 204         return 0;
 205 }