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63b7cb0660
Murmur3 hash is a better hash that djb2 and has a lower chance of hash collisions, so switch over to using it. Signed-off-by: John Johansen <john.johansen@canonical.com> Acked-by: Christian Boltz <apparmor@cboltz.de>
64 lines
1.9 KiB
C
64 lines
1.9 KiB
C
/*-----------------------------------------------------------------------------
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* MurmurHash3 was written by Austin Appleby, and is placed in the public
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* domain.
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*
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* This implementation was written by Shane Day, and is also public domain.
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*
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* This is a portable ANSI C implementation of MurmurHash3_x86_32 (Murmur3A)
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* with support for progressive processing.
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*/
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/* ------------------------------------------------------------------------- */
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/* Determine what native type to use for uint32_t */
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/* We can't use the name 'uint32_t' here because it will conflict with
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* any version provided by the system headers or application. */
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/* First look for special cases */
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#if defined(_MSC_VER)
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#define MH_UINT32 unsigned long
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#endif
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/* If the compiler says it's C99 then take its word for it */
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#if !defined(MH_UINT32) && ( \
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defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L )
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#include <stdint.h>
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#define MH_UINT32 uint32_t
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#endif
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/* Otherwise try testing against max value macros from limit.h */
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#if !defined(MH_UINT32)
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#include <limits.h>
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#if (USHRT_MAX == 0xffffffffUL)
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#define MH_UINT32 unsigned short
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#elif (UINT_MAX == 0xffffffffUL)
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#define MH_UINT32 unsigned int
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#elif (ULONG_MAX == 0xffffffffUL)
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#define MH_UINT32 unsigned long
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#endif
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#endif
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#if !defined(MH_UINT32)
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#error Unable to determine type name for unsigned 32-bit int
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#endif
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/* I'm yet to work on a platform where 'unsigned char' is not 8 bits */
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#define MH_UINT8 unsigned char
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/* ------------------------------------------------------------------------- */
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/* Prototypes */
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#ifdef __cplusplus
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extern "C" {
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#endif
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void PMurHash32_Process(MH_UINT32 *ph1, MH_UINT32 *pcarry, const void *key, int len);
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MH_UINT32 PMurHash32_Result(MH_UINT32 h1, MH_UINT32 carry, MH_UINT32 total_length);
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MH_UINT32 PMurHash32(MH_UINT32 seed, const void *key, int len);
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void PMurHash32_test(const void *key, int len, MH_UINT32 seed, void *out);
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#ifdef __cplusplus
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}
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#endif
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