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| author | Furkan Onder <furkanonder@protonmail.com> | 2023-02-19 00:22:02 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2023-02-19 00:22:02 (GMT) |
| commit | 61f1e67c6fcbf80eb9be2b75f7d62954e28c89e6 (patch) | |
| tree | 74e32f1ed356fa4cb6cf6013c2cf2aca10046ff3 /Objects/sliceobject.c | |
| parent | 5170caf3059fdacc92d7370eecb9fe4f0c5a1c76 (diff) | |
| download | cpython-61f1e67c6fcbf80eb9be2b75f7d62954e28c89e6.zip cpython-61f1e67c6fcbf80eb9be2b75f7d62954e28c89e6.tar.gz cpython-61f1e67c6fcbf80eb9be2b75f7d62954e28c89e6.tar.bz2 | |
GH-84783: Make the slice object hashable (GH-101264)
Diffstat (limited to 'Objects/sliceobject.c')
| -rw-r--r-- | Objects/sliceobject.c | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/Objects/sliceobject.c b/Objects/sliceobject.c index 5694bd9..5d2e6ad 100644 --- a/Objects/sliceobject.c +++ b/Objects/sliceobject.c @@ -628,6 +628,42 @@ slice_traverse(PySliceObject *v, visitproc visit, void *arg) return 0; } +/* code based on tuplehash() of Objects/tupleobject.c */ +#if SIZEOF_PY_UHASH_T > 4 +#define _PyHASH_XXPRIME_1 ((Py_uhash_t)11400714785074694791ULL) +#define _PyHASH_XXPRIME_2 ((Py_uhash_t)14029467366897019727ULL) +#define _PyHASH_XXPRIME_5 ((Py_uhash_t)2870177450012600261ULL) +#define _PyHASH_XXROTATE(x) ((x << 31) | (x >> 33)) /* Rotate left 31 bits */ +#else +#define _PyHASH_XXPRIME_1 ((Py_uhash_t)2654435761UL) +#define _PyHASH_XXPRIME_2 ((Py_uhash_t)2246822519UL) +#define _PyHASH_XXPRIME_5 ((Py_uhash_t)374761393UL) +#define _PyHASH_XXROTATE(x) ((x << 13) | (x >> 19)) /* Rotate left 13 bits */ +#endif + +static Py_hash_t +slicehash(PySliceObject *v) +{ + Py_uhash_t acc = _PyHASH_XXPRIME_5; +#define _PyHASH_SLICE_PART(com) { \ + Py_uhash_t lane = PyObject_Hash(v->com); \ + if(lane == (Py_uhash_t)-1) { \ + return -1; \ + } \ + acc += lane * _PyHASH_XXPRIME_2; \ + acc = _PyHASH_XXROTATE(acc); \ + acc *= _PyHASH_XXPRIME_1; \ +} + _PyHASH_SLICE_PART(start); + _PyHASH_SLICE_PART(stop); + _PyHASH_SLICE_PART(step); +#undef _PyHASH_SLICE_PART + if(acc == (Py_uhash_t)-1) { + return 1546275796; + } + return acc; +} + PyTypeObject PySlice_Type = { PyVarObject_HEAD_INIT(&PyType_Type, 0) "slice", /* Name of this type */ @@ -642,7 +678,7 @@ PyTypeObject PySlice_Type = { 0, /* tp_as_number */ 0, /* tp_as_sequence */ 0, /* tp_as_mapping */ - PyObject_HashNotImplemented, /* tp_hash */ + (hashfunc)slicehash, /* tp_hash */ 0, /* tp_call */ 0, /* tp_str */ PyObject_GenericGetAttr, /* tp_getattro */ |