object.h

   1 #ifndef OBJECT_H
   2 #define OBJECT_H
   3
   4 struct object_list {
   5         struct object *item;
   6         struct object_list *next;
   7 };
   8
   9 struct object_array {
  10         unsigned int nr;
  11         unsigned int alloc;
  12         struct object_array_entry {
  13                 struct object *item;
  14                 /*
  15                  * name or NULL.  If non-NULL, the memory pointed to
  16                  * is owned by this object *except* if it points at
  17                  * object_array_slopbuf, which is a static copy of the
  18                  * empty string.
  19                  */
  20                 char *name;
  21                 unsigned mode;
  22         } *objects;
  23 };
  24
  25 #define OBJECT_ARRAY_INIT { 0, 0, NULL }
  26
  27 #define TYPE_BITS   3
  28 #define FLAG_BITS  27
  29
  30 /*
  31  * The object type is stored in 3 bits.
  32  */
  33 struct object {
  34         unsigned parsed : 1;
  35         unsigned used : 1;
  36         unsigned type : TYPE_BITS;
  37         unsigned flags : FLAG_BITS;
  38         unsigned char sha1[20];
  39 };
  40
  41 extern const char *typename(unsigned int type);
  42 extern int type_from_string(const char *str);
  43
  44 extern unsigned int get_max_object_index(void);
  45 extern struct object *get_indexed_object(unsigned int);
  46
  47 /*
  48  * This can be used to see if we have heard of the object before, but
  49  * it can return "yes we have, and here is a half-initialised object"
  50  * for an object that we haven't loaded/parsed yet.
  51  *
  52  * When parsing a commit to create an in-core commit object, its
  53  * parents list holds commit objects that represent its parents, but
  54  * they are expected to be lazily initialized and do not know what
  55  * their trees or parents are yet.  When this function returns such a
  56  * half-initialised objects, the caller is expected to initialize them
  57  * by calling parse_object() on them.
  58  */
  59 struct object *lookup_object(const unsigned char *sha1);
  60
  61 extern void *create_object(const unsigned char *sha1, int type, void *obj);
  62
  63 /*
  64  * Returns the object, having parsed it to find out what it is.
  65  *
  66  * Returns NULL if the object is missing or corrupt.
  67  */
  68 struct object *parse_object(const unsigned char *sha1);
  69
  70 /*
  71  * Like parse_object, but will die() instead of returning NULL. If the
  72  * "name" parameter is not NULL, it is included in the error message
  73  * (otherwise, the sha1 hex is given).
  74  */
  75 struct object *parse_object_or_die(const unsigned char *sha1, const char *name);
  76
  77 /* Given the result of read_sha1_file(), returns the object after
  78  * parsing it.  eaten_p indicates if the object has a borrowed copy
  79  * of buffer and the caller should not free() it.
  80  */
  81 struct object *parse_object_buffer(const unsigned char *sha1, enum object_type type, unsigned long size, void *buffer, int *eaten_p);
  82
  83 /** Returns the object, with potentially excess memory allocated. **/
  84 struct object *lookup_unknown_object(const unsigned  char *sha1);
  85
  86 struct object_list *object_list_insert(struct object *item,
  87                                        struct object_list **list_p);
  88
  89 int object_list_contains(struct object_list *list, struct object *obj);
  90
  91 /* Object array handling .. */
  92 void add_object_array(struct object *obj, const char *name, struct object_array *array);
  93 void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode);
  94
  95 typedef int (*object_array_each_func_t)(struct object_array_entry *, void *);
  96
  97 /*
  98  * Apply want to each entry in array, retaining only the entries for
  99  * which the function returns true.  Preserve the order of the entries
 100  * that are retained.
 101  */
 102 void object_array_filter(struct object_array *array,
 103                          object_array_each_func_t want, void *cb_data);
 104
 105 /*
 106  * Remove from array all but the first entry with a given name.
 107  * Warning: this function uses an O(N^2) algorithm.
 108  */
 109 void object_array_remove_duplicates(struct object_array *array);
 110
 111 void clear_object_flags(unsigned flags);
 112
 113 #endif /* OBJECT_H */