python3.12/cpython/setobject.h

0001 #ifndef Py_CPYTHON_SETOBJECT_H
0002 #  error "this header file must not be included directly"
0003 #endif
0004
0005 /* There are three kinds of entries in the table:
0006
0007 1. Unused:  key == NULL and hash == 0
0008 2. Dummy:   key == dummy and hash == -1
0009 3. Active:  key != NULL and key != dummy and hash != -1
0010
0011 The hash field of Unused slots is always zero.
0012
0013 The hash field of Dummy slots are set to -1
0014 meaning that dummy entries can be detected by
0015 either entry->key==dummy or by entry->hash==-1.
0016 */
0017
0018 #define PySet_MINSIZE 8
0019
0020 typedef struct {
0021     PyObject *key;
0022     Py_hash_t hash;             /* Cached hash code of the key */
0023 } setentry;
0024
0025 /* The SetObject data structure is shared by set and frozenset objects.
0026
0027 Invariant for sets:
0028  - hash is -1
0029
0030 Invariants for frozensets:
0031  - data is immutable.
0032  - hash is the hash of the frozenset or -1 if not computed yet.
0033
0034 */
0035
0036 typedef struct {
0037     PyObject_HEAD
0038
0039     Py_ssize_t fill;            /* Number active and dummy entries*/
0040     Py_ssize_t used;            /* Number active entries */
0041
0042     /* The table contains mask + 1 slots, and that's a power of 2.
0043      * We store the mask instead of the size because the mask is more
0044      * frequently needed.
0045      */
0046     Py_ssize_t mask;
0047
0048     /* The table points to a fixed-size smalltable for small tables
0049      * or to additional malloc'ed memory for bigger tables.
0050      * The table pointer is never NULL which saves us from repeated
0051      * runtime null-tests.
0052      */
0053     setentry *table;
0054     Py_hash_t hash;             /* Only used by frozenset objects */
0055     Py_ssize_t finger;          /* Search finger for pop() */
0056
0057     setentry smalltable[PySet_MINSIZE];
0058     PyObject *weakreflist;      /* List of weak references */
0059 } PySetObject;
0060
0061 #define _PySet_CAST(so) \
0062     (assert(PyAnySet_Check(so)), _Py_CAST(PySetObject*, so))
0063
0064 static inline Py_ssize_t PySet_GET_SIZE(PyObject *so) {
0065     return _PySet_CAST(so)->used;
0066 }
0067 #define PySet_GET_SIZE(so) PySet_GET_SIZE(_PyObject_CAST(so))
0068
0069 PyAPI_DATA(PyObject *) _PySet_Dummy;
0070
0071 PyAPI_FUNC(int) _PySet_NextEntry(PyObject *set, Py_ssize_t *pos, PyObject **key, Py_hash_t *hash);
0072 PyAPI_FUNC(int) _PySet_Update(PyObject *set, PyObject *iterable);