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 #include "delta.h"
   8
   9 struct object **objs;
  10 int nr_objs;
  11 static int obj_allocs;
  12
  13 static int find_object(unsigned char *sha1)
  14 {
  15         int first = 0, last = nr_objs;
  16
  17         while (first < last) {
  18                 int next = (first + last) / 2;
  19                 struct object *obj = objs[next];
  20                 int cmp;
  21
  22                 cmp = memcmp(sha1, obj->sha1, 20);
  23                 if (!cmp)
  24                         return next;
  25                 if (cmp < 0) {
  26                         last = next;
  27                         continue;
  28                 }
  29                 first = next+1;
  30         }
  31         return -first-1;
  32 }
  33
  34 struct object *lookup_object(unsigned char *sha1)
  35 {
  36         int pos = find_object(sha1);
  37         if (pos >= 0)
  38                 return objs[pos];
  39         return NULL;
  40 }
  41
  42 void created_object(unsigned char *sha1, struct object *obj)
  43 {
  44         int pos = find_object(sha1);
  45
  46         obj->parsed = 0;
  47         memcpy(obj->sha1, sha1, 20);
  48         obj->type = NULL;
  49         obj->refs = NULL;
  50         obj->used = 0;
  51
  52         if (pos >= 0)
  53                 die("Inserting %s twice\n", sha1_to_hex(sha1));
  54         pos = -pos-1;
  55
  56         if (obj_allocs == nr_objs) {
  57                 obj_allocs = alloc_nr(obj_allocs);
  58                 objs = xrealloc(objs, obj_allocs * sizeof(struct object *));
  59         }
  60
  61         /* Insert it into the right place */
  62         memmove(objs + pos + 1, objs + pos, (nr_objs - pos) *
  63                 sizeof(struct object *));
  64
  65         objs[pos] = obj;
  66         nr_objs++;
  67 }
  68
  69 void add_ref(struct object *refer, struct object *target)
  70 {
  71         struct object_list **pp = &refer->refs;
  72         struct object_list *p;
  73
  74         while ((p = *pp) != NULL) {
  75                 if (p->item == target)
  76                         return;
  77                 pp = &p->next;
  78         }
  79
  80         target->used = 1;
  81         p = xmalloc(sizeof(*p));
  82         p->item = target;
  83         p->next = NULL;
  84         *pp = p;
  85 }
  86
  87 void mark_reachable(struct object *obj, unsigned int mask)
  88 {
  89         struct object_list *p = obj->refs;
  90
  91         /* If we've been here already, don't bother */
  92         if (obj->flags & mask)
  93                 return;
  94         obj->flags |= mask;
  95         while (p) {
  96                 mark_reachable(p->item, mask);
  97                 p = p->next;
  98         }
  99 }
 100
 101 struct object *parse_object(unsigned char *sha1)
 102 {
 103         unsigned long mapsize;
 104         void *map = map_sha1_file(sha1, &mapsize);
 105         if (map) {
 106                 int is_delta;
 107                 struct object *obj;
 108                 char type[100];
 109                 unsigned long size;
 110                 void *buffer = unpack_sha1_file(map, mapsize, type, &size);
 111                 munmap(map, mapsize);
 112                 if (!buffer)
 113                         return NULL;
 114                 is_delta = !strcmp(type, "delta");
 115                 if (!is_delta && check_sha1_signature(sha1, buffer, size, type) < 0)
 116                         printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
 117                 if (is_delta) {
 118                         struct delta *delta = lookup_delta(sha1);
 119                         parse_delta_buffer(delta, buffer, size);
 120                         obj = (struct object *) delta;
 121                 } else if (!strcmp(type, "blob")) {
 122                         struct blob *blob = lookup_blob(sha1);
 123                         parse_blob_buffer(blob, buffer, size);
 124                         obj = &blob->object;
 125                 } else if (!strcmp(type, "tree")) {
 126                         struct tree *tree = lookup_tree(sha1);
 127                         parse_tree_buffer(tree, buffer, size);
 128                         obj = &tree->object;
 129                 } else if (!strcmp(type, "commit")) {
 130                         struct commit *commit = lookup_commit(sha1);
 131                         parse_commit_buffer(commit, buffer, size);
 132                         if (!commit->buffer) {
 133                                 commit->buffer = buffer;
 134                                 buffer = NULL;
 135                         }
 136                         obj = &commit->object;
 137                 } else if (!strcmp(type, "tag")) {
 138                         struct tag *tag = lookup_tag(sha1);
 139                         parse_tag_buffer(tag, buffer, size);
 140                         obj = &tag->object;
 141                 } else {
 142                         obj = NULL;
 143                 }
 144                 free(buffer);
 145                 return obj;
 146         }
 147         return NULL;
 148 }