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The C and C++ Include Header Files

cat -n /usr/include/python3.14/internal/pycore_pyhash.h

     1	#ifndef Py_INTERNAL_PYHASH_H
     2	#define Py_INTERNAL_PYHASH_H
     3	
     4	#ifndef Py_BUILD_CORE
     5	#  error "this header requires Py_BUILD_CORE define"
     6	#endif
     7	
     8	// Similar to Py_HashPointer(), but don't replace -1 with -2.
     9	static inline Py_hash_t
    10	_Py_HashPointerRaw(const void *ptr)
    11	{
    12	    uintptr_t x = (uintptr_t)ptr;
    13	    Py_BUILD_ASSERT(sizeof(x) == sizeof(ptr));
    14	
    15	    // Bottom 3 or 4 bits are likely to be 0; rotate x by 4 to the right
    16	    // to avoid excessive hash collisions for dicts and sets.
    17	    x = (x >> 4) | (x << (8 * sizeof(uintptr_t) - 4));
    18	
    19	    Py_BUILD_ASSERT(sizeof(x) == sizeof(Py_hash_t));
    20	    return (Py_hash_t)x;
    21	}
    22	
    23	/* Hash secret
    24	 *
    25	 * memory layout on 64 bit systems
    26	 *   cccccccc cccccccc cccccccc  uc -- unsigned char[24]
    27	 *   pppppppp ssssssss ........  fnv -- two Py_hash_t
    28	 *   k0k0k0k0 k1k1k1k1 ........  siphash -- two uint64_t
    29	 *   ........ ........ ssssssss  djbx33a -- 16 bytes padding + one Py_hash_t
    30	 *   ........ ........ eeeeeeee  pyexpat XML hash salt
    31	 *
    32	 * memory layout on 32 bit systems
    33	 *   cccccccc cccccccc cccccccc  uc
    34	 *   ppppssss ........ ........  fnv -- two Py_hash_t
    35	 *   k0k0k0k0 k1k1k1k1 ........  siphash -- two uint64_t (*)
    36	 *   ........ ........ ssss....  djbx33a -- 16 bytes padding + one Py_hash_t
    37	 *   ........ ........ eeee....  pyexpat XML hash salt
    38	 *
    39	 * (*) The siphash member may not be available on 32 bit platforms without
    40	 *     an unsigned int64 data type.
    41	 */
    42	typedef union {
    43	    /* ensure 24 bytes */
    44	    unsigned char uc[24];
    45	    /* two Py_hash_t for FNV */
    46	    struct {
    47	        Py_hash_t prefix;
    48	        Py_hash_t suffix;
    49	    } fnv;
    50	    /* two uint64 for SipHash24 */
    51	    struct {
    52	        uint64_t k0;
    53	        uint64_t k1;
    54	    } siphash;
    55	    /* a different (!) Py_hash_t for small string optimization */
    56	    struct {
    57	        unsigned char padding[16];
    58	        Py_hash_t suffix;
    59	    } djbx33a;
    60	    struct {
    61	        unsigned char padding[16];
    62	        Py_hash_t hashsalt;
    63	    } expat;
    64	} _Py_HashSecret_t;
    65	
    66	// Export for '_elementtree' shared extension
    67	PyAPI_DATA(_Py_HashSecret_t) _Py_HashSecret;
    68	
    69	#ifdef Py_DEBUG
    70	extern int _Py_HashSecret_Initialized;
    71	#endif
    72	
    73	
    74	#ifndef MS_WINDOWS
    75	# define _py_urandom_cache_INIT \
    76	    { \
    77	        .fd = -1, \
    78	    }
    79	#else
    80	# define _py_urandom_cache_INIT {0}
    81	#endif
    82	
    83	#define pyhash_state_INIT \
    84	    { \
    85	        .urandom_cache = _py_urandom_cache_INIT, \
    86	    }
    87	
    88	
    89	extern uint64_t _Py_KeyedHash(uint64_t key, const void *src, Py_ssize_t src_sz);
    90	
    91	#endif  // !Py_INTERNAL_PYHASH_H