cpython/Objects/dict-common.h
INADA Naoki 778928b0c7 bpo-29304: Simplify dict lookup functions (GH-2407)
* remove hashpos parameter from lookdict functions.
* remove many duplicated code from lookdict functions.
2017-08-03 23:45:15 +09:00

76 lines
2.3 KiB
C

#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, 8 is minimum. */
union {
int8_t as_1[8];
int16_t as_2[4];
int32_t as_4[2];
#if SIZEOF_VOID_P > 4
int64_t as_8[1];
#endif
} dk_indices;
/* "PyDictKeyEntry dk_entries[dk_usable];" array follows:
see the DK_ENTRIES() macro */
};
#endif