text: #ifndef GIT_FSCK_H
  #define GIT_FSCK_H
  
  #define FSCK_ERROR 1
  #define FSCK_WARN 2
  
  /*
   * callback function for fsck_walk
   * type is the expected type of the object or OBJ_ANY
   * the return value is:
   *     0	everything OK
   *     <0	error signaled and abort
   *     >0	error signaled and do not abort
   */
  typedef int (*fsck_walk_func)(struct object *obj, int type, void *data);
  
  /* callback for fsck_object, type is FSCK_ERROR or FSCK_WARN */
  typedef int (*fsck_error)(struct object *obj, int type, const char *err, ...);
  
  __attribute__((format (printf, 3, 4)))
  int fsck_error_function(struct object *obj, int type, const char *fmt, ...);
  
  /* descend in all linked child objects
   * the return value is:
   *    -1	error in processing the object
   *    <0	return value of the callback, which lead to an abort
   *    >0	return value of the first signaled error >0 (in the case of no other errors)
   *    0		everything OK
   */
  int fsck_walk(struct object *obj, fsck_walk_func walk, void *data);
  /* If NULL is passed for data, we assume the object is local and read it. */
  int fsck_object(struct object *obj, void *data, unsigned long size,
  	int strict, fsck_error error_func);
  
  #endif
  