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Diffstat (limited to 'Include/pyhash.h')
| -rw-r--r-- | Include/pyhash.h | 145 |
1 files changed, 0 insertions, 145 deletions
diff --git a/Include/pyhash.h b/Include/pyhash.h deleted file mode 100644 index dbcc974..0000000 --- a/Include/pyhash.h +++ /dev/null @@ -1,145 +0,0 @@ -#ifndef Py_HASH_H - -#define Py_HASH_H -#ifdef __cplusplus -extern "C" { -#endif - -/* Helpers for hash functions */ -#ifndef Py_LIMITED_API -PyAPI_FUNC(Py_hash_t) _Py_HashDouble(double); -PyAPI_FUNC(Py_hash_t) _Py_HashPointer(void*); -PyAPI_FUNC(Py_hash_t) _Py_HashBytes(const void*, Py_ssize_t); -#endif - -/* Prime multiplier used in string and various other hashes. */ -#define _PyHASH_MULTIPLIER 1000003UL /* 0xf4243 */ - -/* Parameters used for the numeric hash implementation. See notes for - _Py_HashDouble in Python/pyhash.c. Numeric hashes are based on - reduction modulo the prime 2**_PyHASH_BITS - 1. */ - -#if SIZEOF_VOID_P >= 8 -# define _PyHASH_BITS 61 -#else -# define _PyHASH_BITS 31 -#endif - -#define _PyHASH_MODULUS (((size_t)1 << _PyHASH_BITS) - 1) -#define _PyHASH_INF 314159 -#define _PyHASH_NAN 0 -#define _PyHASH_IMAG _PyHASH_MULTIPLIER - - -/* hash secret - * - * memory layout on 64 bit systems - * cccccccc cccccccc cccccccc uc -- unsigned char[24] - * pppppppp ssssssss ........ fnv -- two Py_hash_t - * k0k0k0k0 k1k1k1k1 ........ siphash -- two uint64_t - * ........ ........ ssssssss djbx33a -- 16 bytes padding + one Py_hash_t - * ........ ........ eeeeeeee pyexpat XML hash salt - * - * memory layout on 32 bit systems - * cccccccc cccccccc cccccccc uc - * ppppssss ........ ........ fnv -- two Py_hash_t - * k0k0k0k0 k1k1k1k1 ........ siphash -- two uint64_t (*) - * ........ ........ ssss.... djbx33a -- 16 bytes padding + one Py_hash_t - * ........ ........ eeee.... pyexpat XML hash salt - * - * (*) The siphash member may not be available on 32 bit platforms without - * an unsigned int64 data type. - */ -#ifndef Py_LIMITED_API -typedef union { - /* ensure 24 bytes */ - unsigned char uc[24]; - /* two Py_hash_t for FNV */ - struct { - Py_hash_t prefix; - Py_hash_t suffix; - } fnv; - /* two uint64 for SipHash24 */ - struct { - uint64_t k0; - uint64_t k1; - } siphash; - /* a different (!) Py_hash_t for small string optimization */ - struct { - unsigned char padding[16]; - Py_hash_t suffix; - } djbx33a; - struct { - unsigned char padding[16]; - Py_hash_t hashsalt; - } expat; -} _Py_HashSecret_t; -PyAPI_DATA(_Py_HashSecret_t) _Py_HashSecret; -#endif - -#ifdef Py_DEBUG -PyAPI_DATA(int) _Py_HashSecret_Initialized; -#endif - - -/* hash function definition */ -#ifndef Py_LIMITED_API -typedef struct { - Py_hash_t (*const hash)(const void *, Py_ssize_t); - const char *name; - const int hash_bits; - const int seed_bits; -} PyHash_FuncDef; - -PyAPI_FUNC(PyHash_FuncDef*) PyHash_GetFuncDef(void); -#endif - - -/* cutoff for small string DJBX33A optimization in range [1, cutoff). - * - * About 50% of the strings in a typical Python application are smaller than - * 6 to 7 chars. However DJBX33A is vulnerable to hash collision attacks. - * NEVER use DJBX33A for long strings! - * - * A Py_HASH_CUTOFF of 0 disables small string optimization. 32 bit platforms - * should use a smaller cutoff because it is easier to create colliding - * strings. A cutoff of 7 on 64bit platforms and 5 on 32bit platforms should - * provide a decent safety margin. - */ -#ifndef Py_HASH_CUTOFF -# define Py_HASH_CUTOFF 0 -#elif (Py_HASH_CUTOFF > 7 || Py_HASH_CUTOFF < 0) -# error Py_HASH_CUTOFF must in range 0...7. -#endif /* Py_HASH_CUTOFF */ - - -/* hash algorithm selection - * - * The values for Py_HASH_SIPHASH24 and Py_HASH_FNV are hard-coded in the - * configure script. - * - * - FNV is available on all platforms and architectures. - * - SIPHASH24 only works on platforms that don't require aligned memory for integers. - * - With EXTERNAL embedders can provide an alternative implementation with:: - * - * PyHash_FuncDef PyHash_Func = {...}; - * - * XXX: Figure out __declspec() for extern PyHash_FuncDef. - */ -#define Py_HASH_EXTERNAL 0 -#define Py_HASH_SIPHASH24 1 -#define Py_HASH_FNV 2 - -#ifndef Py_HASH_ALGORITHM -# ifndef HAVE_ALIGNED_REQUIRED -# define Py_HASH_ALGORITHM Py_HASH_SIPHASH24 -# else -# define Py_HASH_ALGORITHM Py_HASH_FNV -# endif /* uint64_t && uint32_t && aligned */ -#endif /* Py_HASH_ALGORITHM */ - -#ifdef __cplusplus -} -#endif - -#endif /* !Py_HASH_H */ |