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 (!strcmp(type, blob_type)) {
 103                 return &lookup_blob(sha1)->object;
 104         } else if (!strcmp(type, tree_type)) {
 105                 return &lookup_tree(sha1)->object;
 106         } else if (!strcmp(type, commit_type)) {
 107                 return &lookup_commit(sha1)->object;
 108         } else if (!strcmp(type, tag_type)) {
 109                 return &lookup_tag(sha1)->object;
 110         } else {
 111                 error("Unknown type %s", type);
 112                 return NULL;
 113         }
 114 }
 115
 116 struct object *parse_object(const unsigned char *sha1)
 117 {
 118         unsigned long size;
 119         char type[20];
 120         void *buffer = read_sha1_file(sha1, type, &size);
 121         if (buffer) {
 122                 struct object *obj;
 123                 if (check_sha1_signature(sha1, buffer, size, type) < 0)
 124                         printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
 125                 if (!strcmp(type, "blob")) {
 126                         struct blob *blob = lookup_blob(sha1);
 127                         parse_blob_buffer(blob, buffer, size);
 128                         obj = &blob->object;
 129                 } else if (!strcmp(type, "tree")) {
 130                         struct tree *tree = lookup_tree(sha1);
 131                         parse_tree_buffer(tree, buffer, size);
 132                         obj = &tree->object;
 133                 } else if (!strcmp(type, "commit")) {
 134                         struct commit *commit = lookup_commit(sha1);
 135                         parse_commit_buffer(commit, buffer, size);
 136                         if (!commit->buffer) {
 137                                 commit->buffer = buffer;
 138                                 buffer = NULL;
 139                         }
 140                         obj = &commit->object;
 141                 } else if (!strcmp(type, "tag")) {
 142                         struct tag *tag = lookup_tag(sha1);
 143                         parse_tag_buffer(tag, buffer, size);
 144                         obj = &tag->object;
 145                 } else {
 146                         obj = NULL;
 147                 }
 148                 free(buffer);
 149                 return obj;
 150         }
 151         return NULL;
 152 }