#include #include /* * Robert Jenkins' function for mixing 32-bit values * http://burtleburtle.net/bob/hash/evahash.html * a, b = random bits, c = input and output */ #define crush_hashmix(a, b, c) do { \ a = a-b; a = a-c; a = a^(c>>13); \ b = b-c; b = b-a; b = b^(a<<8); \ c = c-a; c = c-b; c = c^(b>>13); \ a = a-b; a = a-c; a = a^(c>>12); \ b = b-c; b = b-a; b = b^(a<<16); \ c = c-a; c = c-b; c = c^(b>>5); \ a = a-b; a = a-c; a = a^(c>>3); \ b = b-c; b = b-a; b = b^(a<<10); \ c = c-a; c = c-b; c = c^(b>>15); \ } while (0) #define crush_hash_seed 1315423911 static __u32 crush_hash32_rjenkins1(__u32 a) { __u32 hash = crush_hash_seed ^ a; __u32 b = a; __u32 x = 231232; __u32 y = 1232; crush_hashmix(b, x, hash); crush_hashmix(y, a, hash); return hash; } static __u32 crush_hash32_rjenkins1_2(__u32 a, __u32 b) { __u32 hash = crush_hash_seed ^ a ^ b; __u32 x = 231232; __u32 y = 1232; crush_hashmix(a, b, hash); crush_hashmix(x, a, hash); crush_hashmix(b, y, hash); return hash; } static __u32 crush_hash32_rjenkins1_3(__u32 a, __u32 b, __u32 c) { __u32 hash = crush_hash_seed ^ a ^ b ^ c; __u32 x = 231232; __u32 y = 1232; crush_hashmix(a, b, hash); crush_hashmix(c, x, hash); crush_hashmix(y, a, hash); crush_hashmix(b, x, hash); crush_hashmix(y, c, hash); return hash; } static __u32 crush_hash32_rjenkins1_4(__u32 a, __u32 b, __u32 c, __u32 d) { __u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d; __u32 x = 231232; __u32 y = 1232; crush_hashmix(a, b, hash); crush_hashmix(c, d, hash); crush_hashmix(a, x, hash); crush_hashmix(y, b, hash); crush_hashmix(c, x, hash); crush_hashmix(y, d, hash); return hash; } static __u32 crush_hash32_rjenkins1_5(__u32 a, __u32 b, __u32 c, __u32 d, __u32 e) { __u32 hash = crush_hash_seed ^ a ^ b ^ c ^ d ^ e; __u32 x = 231232; __u32 y = 1232; crush_hashmix(a, b, hash); crush_hashmix(c, d, hash); crush_hashmix(e, x, hash); crush_hashmix(y, a, hash); crush_hashmix(b, x, hash); crush_hashmix(y, c, hash); crush_hashmix(d, x, hash); crush_hashmix(y, e, hash); return hash; } __u32 crush_hash32(int type, __u32 a) { switch (type) { case CRUSH_HASH_RJENKINS1: return crush_hash32_rjenkins1(a); default: return 0; } } __u32 crush_hash32_2(int type, __u32 a, __u32 b) { switch (type) { case CRUSH_HASH_RJENKINS1: return crush_hash32_rjenkins1_2(a, b); default: return 0; } } __u32 crush_hash32_3(int type, __u32 a, __u32 b, __u32 c) { switch (type) { case CRUSH_HASH_RJENKINS1: return crush_hash32_rjenkins1_3(a, b, c); default: return 0; } } __u32 crush_hash32_4(int type, __u32 a, __u32 b, __u32 c, __u32 d) { switch (type) { case CRUSH_HASH_RJENKINS1: return crush_hash32_rjenkins1_4(a, b, c, d); default: return 0; } } __u32 crush_hash32_5(int type, __u32 a, __u32 b, __u32 c, __u32 d, __u32 e) { switch (type) { case CRUSH_HASH_RJENKINS1: return crush_hash32_rjenkins1_5(a, b, c, d, e); default: return 0; } } const char *crush_hash_name(int type) { switch (type) { case CRUSH_HASH_RJENKINS1: return "rjenkins1"; default: return "unknown"; } }