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