1/* Set object interface */
2
3#ifndef Py_SETOBJECT_H
4#define Py_SETOBJECT_H
5#ifdef __cplusplus
6extern "C" {
7#endif
8
9#ifndef Py_LIMITED_API
10
11/* There are three kinds of entries in the table:
12
131. Unused:  key == NULL and hash == 0
142. Dummy:   key == dummy and hash == -1
153. Active:  key != NULL and key != dummy and hash != -1
16
17The hash field of Unused slots is always zero.
18
19The hash field of Dummy slots are set to -1
20meaning that dummy entries can be detected by
21either entry->key==dummy or by entry->hash==-1.
22*/
23
24#define PySet_MINSIZE 8
25
26typedef struct {
27    PyObject *key;
28    Py_hash_t hash;             /* Cached hash code of the key */
29} setentry;
30
31/* The SetObject data structure is shared by set and frozenset objects.
32
33Invariant for sets:
34 - hash is -1
35
36Invariants for frozensets:
37 - data is immutable.
38 - hash is the hash of the frozenset or -1 if not computed yet.
39
40*/
41
42typedef struct {
43    PyObject_HEAD
44
45    Py_ssize_t fill;            /* Number active and dummy entries*/
46    Py_ssize_t used;            /* Number active entries */
47
48    /* The table contains mask + 1 slots, and that's a power of 2.
49     * We store the mask instead of the size because the mask is more
50     * frequently needed.
51     */
52    Py_ssize_t mask;
53
54    /* The table points to a fixed-size smalltable for small tables
55     * or to additional malloc'ed memory for bigger tables.
56     * The table pointer is never NULL which saves us from repeated
57     * runtime null-tests.
58     */
59    setentry *table;
60    Py_hash_t hash;             /* Only used by frozenset objects */
61    Py_ssize_t finger;          /* Search finger for pop() */
62
63    setentry smalltable[PySet_MINSIZE];
64    PyObject *weakreflist;      /* List of weak references */
65} PySetObject;
66
67#define PySet_GET_SIZE(so) (((PySetObject *)(so))->used)
68
69PyAPI_DATA(PyObject *) _PySet_Dummy;
70
71PyAPI_FUNC(int) _PySet_NextEntry(PyObject *set, Py_ssize_t *pos, PyObject **key, Py_hash_t *hash);
72PyAPI_FUNC(int) _PySet_Update(PyObject *set, PyObject *iterable);
73PyAPI_FUNC(int) PySet_ClearFreeList(void);
74
75#endif /* Section excluded by Py_LIMITED_API */
76
77PyAPI_DATA(PyTypeObject) PySet_Type;
78PyAPI_DATA(PyTypeObject) PyFrozenSet_Type;
79PyAPI_DATA(PyTypeObject) PySetIter_Type;
80
81PyAPI_FUNC(PyObject *) PySet_New(PyObject *);
82PyAPI_FUNC(PyObject *) PyFrozenSet_New(PyObject *);
83
84PyAPI_FUNC(int) PySet_Add(PyObject *set, PyObject *key);
85PyAPI_FUNC(int) PySet_Clear(PyObject *set);
86PyAPI_FUNC(int) PySet_Contains(PyObject *anyset, PyObject *key);
87PyAPI_FUNC(int) PySet_Discard(PyObject *set, PyObject *key);
88PyAPI_FUNC(PyObject *) PySet_Pop(PyObject *set);
89PyAPI_FUNC(Py_ssize_t) PySet_Size(PyObject *anyset);
90
91#define PyFrozenSet_CheckExact(ob) (Py_TYPE(ob) == &PyFrozenSet_Type)
92#define PyAnySet_CheckExact(ob) \
93    (Py_TYPE(ob) == &PySet_Type || Py_TYPE(ob) == &PyFrozenSet_Type)
94#define PyAnySet_Check(ob) \
95    (Py_TYPE(ob) == &PySet_Type || Py_TYPE(ob) == &PyFrozenSet_Type || \
96      PyType_IsSubtype(Py_TYPE(ob), &PySet_Type) || \
97      PyType_IsSubtype(Py_TYPE(ob), &PyFrozenSet_Type))
98#define PySet_Check(ob) \
99    (Py_TYPE(ob) == &PySet_Type || \
100    PyType_IsSubtype(Py_TYPE(ob), &PySet_Type))
101#define   PyFrozenSet_Check(ob) \
102    (Py_TYPE(ob) == &PyFrozenSet_Type || \
103      PyType_IsSubtype(Py_TYPE(ob), &PyFrozenSet_Type))
104
105#ifdef __cplusplus
106}
107#endif
108#endif /* !Py_SETOBJECT_H */
109