#ifndef sph_memreg_h
#define sph_memreg_h

/* memreg registers memory in a local variable, for example to free all memory allocated at point.
the variables memreg_register and memreg_index will also be available.
usage:
   memreg_init(2);
   memreg_add(&variable-1);
   memreg_add(&variable-2);
   memreg_free; */

#define memreg_init(register_size) \
  void* memreg_register[register_size]; \
  unsigned int memreg_index; \
  memreg_index = 0

/** add a pointer to the register. memreg_init must have been called
     with sufficient size for all pointers to be added */
#define memreg_add(address) \
  memreg_register[memreg_index] = address; \
  memreg_index += 1
#define memreg_free \
  while (memreg_index) { \
    /* free all currently registered pointers */ \
    memreg_index -= 1; \
    free((memreg_register[memreg_index])); \
  }
/* the *_named variant of memreg supports multiple concurrent registers identified by name
usage:
   memreg_init_named(testname, 4);
   memreg_add_named(testname, &variable);
   memreg_free_named(testname); */

#define memreg_init_named(register_id, register_size) \
  void* memreg_register##_##register_id[register_size]; \
  unsigned int memreg_index##_##register_id; \
  memreg_index##_##register_id = 0

/** does not protect against buffer overflow */
#define memreg_add_named(register_id, address) \
  memreg_register##_##register_id[memreg_index##_##register_id] = address; \
  memreg_index##_##register_id += 1
#define memreg_free_named(register_id) \
  while (memreg_index##_##register_id) { \
    memreg_index##_##register_id -= 1; \
    free((memreg_register##_##register_id[memreg_index##_##register_id])); \
  }

/* memreg2 is like memreg but additionally supports specifying a handler function {void* -> void} with each address that will be used to free the data */

#define memreg2_init_named(register_id, register_size) \
  memreg2_t memreg2_register##_##register_id[register_size]; \
  unsigned int memreg2_index##_##register_id; \
  memreg2_index##_##register_id = 0
#define memreg2_add_named(register_id, _address, _handler) \
  (memreg2_register##_##register_id[memreg2_index##_##register_id]).address = _address; \
  (memreg2_register##_##register_id[memreg2_index##_##register_id]).handler = ((void (*)(void*))(_handler)); \
  memreg2_index##_##register_id += 1
#define memreg2_free_named(register_id) \
  while (memreg2_index##_##register_id) { \
    memreg2_index##_##register_id -= 1; \
    ((memreg2_register##_##register_id[memreg2_index##_##register_id]).handler)(((memreg2_register##_##register_id[memreg2_index##_##register_id]).address)); \
  }
typedef struct {
  void* address;
  void (*handler)(void*);
} memreg2_t;
#endif