#ifndef Py_DICT_COMMON_H
#define Py_DICT_COMMON_H

typedef struct {
 /* Cached hash code of me_key. */
 Py_hash_t me_hash;
 PyObject *me_key;
 PyObject *me_value; /* This field is only meaningful for combined tables */
} PyDictKeyEntry;

/* dict_lookup_func() returns index of entry which can be used like DK_ENTRIES(dk)[index].
 * -1 when no entry found, -3 when compare raises error.
 */
typedef Py_ssize_t (*dict_lookup_func)
 (PyDictObject *mp, PyObject *key, Py_hash_t hash, PyObject **value_addr);

#define DKIX_EMPTY (-1)
#define DKIX_DUMMY (-2) /* Used internally */
#define DKIX_ERROR (-3)

/* See dictobject.c for actual layout of DictKeysObject */
struct _dictkeysobject {
 Py_ssize_t dk_refcnt;

 /* Size of the hash table (dk_indices). It must be a power of 2. */
 Py_ssize_t dk_size;

 /* Function to lookup in the hash table (dk_indices):

 - lookdict(): general-purpose, and may return DKIX_ERROR if (and
 only if) a comparison raises an exception.

 - lookdict_unicode(): specialized to Unicode string keys, comparison of
 which can never raise an exception; that function can never return
 DKIX_ERROR.

 - lookdict_unicode_nodummy(): similar to lookdict_unicode() but further
 specialized for Unicode string keys that cannot be the <dummy> value.

 - lookdict_split(): Version of lookdict() for split tables. */
 dict_lookup_func dk_lookup;

 /* Number of usable entries in dk_entries. */
 Py_ssize_t dk_usable;

 /* Number of used entries in dk_entries. */
 Py_ssize_t dk_nentries;

 /* Actual hash table of dk_size entries. It holds indices in dk_entries,
 or DKIX_EMPTY(-1) or DKIX_DUMMY(-2).

 Indices must be: 0 <= indice < USABLE_FRACTION(dk_size).

 The size in bytes of an indice depends on dk_size:

 - 1 byte if dk_size <= 0xff (char*)
 - 2 bytes if dk_size <= 0xffff (int16_t*)
 - 4 bytes if dk_size <= 0xffffffff (int32_t*)
 - 8 bytes otherwise (int64_t*)

 Dynamically sized, SIZEOF_VOID_P is minimum. */
 char dk_indices[]; /* char is required to avoid strict aliasing. */

 /* "PyDictKeyEntry dk_entries[dk_usable];" array follows:
 see the DK_ENTRIES() macro */
};

#endif