object.hon commit xread/xwrite: clip MAX_IO_SIZE to SSIZE_MAX (a983e6a)
   1#ifndef OBJECT_H
   2#define OBJECT_H
   3
   4struct object_list {
   5        struct object *item;
   6        struct object_list *next;
   7};
   8
   9struct 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 */
  33struct 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
  41extern const char *typename(unsigned int type);
  42extern int type_from_string(const char *str);
  43
  44extern unsigned int get_max_object_index(void);
  45extern 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 */
  59struct object *lookup_object(const unsigned char *sha1);
  60
  61extern 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 */
  68struct 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 */
  75struct 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 */
  81struct 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. **/
  84struct object *lookup_unknown_object(const unsigned  char *sha1);
  85
  86struct object_list *object_list_insert(struct object *item,
  87                                       struct object_list **list_p);
  88
  89int object_list_contains(struct object_list *list, struct object *obj);
  90
  91/* Object array handling .. */
  92void add_object_array(struct object *obj, const char *name, struct object_array *array);
  93void add_object_array_with_mode(struct object *obj, const char *name, struct object_array *array, unsigned mode);
  94
  95typedef 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 */
 102void 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 */
 109void object_array_remove_duplicates(struct object_array *array);
 110
 111void clear_object_flags(unsigned flags);
 112
 113#endif /* OBJECT_H */