hv_func.h
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/* hash a key *-------------------------------------------------------------------------------------- * The "hash seed" feature was added in Perl 5.8.1 to perturb the results * to avoid "algorithmic complexity attacks". * * If USE_HASH_SEED is defined, hash randomisation is done by default * If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done * only if the environment variable PERL_HASH_SEED is set. * (see also perl.c:perl_parse() and S_init_tls_and_interp() and util.c:get_hash_seed()) */ #ifndef PERL_SEEN_HV_FUNC_H /* compile once */ #define PERL_SEEN_HV_FUNC_H #if !( 0 \ || defined(PERL_HASH_FUNC_SIPHASH) \ || defined(PERL_HASH_FUNC_SIPHASH13) \ || defined(PERL_HASH_FUNC_HYBRID_OAATHU_SIPHASH13) \ || defined(PERL_HASH_FUNC_ONE_AT_A_TIME_HARD) \ ) #if IVSIZE == 8 #define PERL_HASH_FUNC_HYBRID_OAATHU_SIPHASH13 #else #define PERL_HASH_FUNC_ONE_AT_A_TIME_HARD #endif #endif #if defined(PERL_HASH_FUNC_SIPHASH) # define PERL_HASH_FUNC "SIPHASH_2_4" # define PERL_HASH_SEED_BYTES 16 # define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_siphash_2_4((seed),(U8*)(str),(len)) #elif defined(PERL_HASH_FUNC_SIPHASH13) # define PERL_HASH_FUNC "SIPHASH_1_3" # define PERL_HASH_SEED_BYTES 16 # define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_siphash_1_3((seed),(U8*)(str),(len)) #elif defined(PERL_HASH_FUNC_HYBRID_OAATHU_SIPHASH13) # define PERL_HASH_FUNC "HYBRID_OAATHU_SIPHASH_1_3" # define PERL_HASH_SEED_BYTES 24 # define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_oaathu_siphash_1_3((seed),(U8*)(str),(len)) #elif defined(PERL_HASH_FUNC_ONE_AT_A_TIME_HARD) # define PERL_HASH_FUNC "ONE_AT_A_TIME_HARD" # define PERL_HASH_SEED_BYTES 8 # define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_one_at_a_time_hard((seed),(U8*)(str),(len)) #endif #ifndef PERL_HASH_WITH_SEED #error "No hash function defined!" #endif #ifndef PERL_HASH_SEED_BYTES #error "PERL_HASH_SEED_BYTES not defined" #endif #ifndef PERL_HASH_FUNC #error "PERL_HASH_FUNC not defined" #endif #ifndef PERL_HASH_SEED # if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT) # define PERL_HASH_SEED PL_hash_seed # elif PERL_HASH_SEED_BYTES == 4 # define PERL_HASH_SEED ((const U8 *)"PeRl") # elif PERL_HASH_SEED_BYTES == 8 # define PERL_HASH_SEED ((const U8 *)"PeRlHaSh") # elif PERL_HASH_SEED_BYTES == 16 # define PERL_HASH_SEED ((const U8 *)"PeRlHaShhAcKpErl") # else # error "No PERL_HASH_SEED definition for " PERL_HASH_FUNC # endif #endif #define PERL_HASH(hash,str,len) PERL_HASH_WITH_SEED(PERL_HASH_SEED,hash,str,len) /* legacy - only mod_perl should be doing this. */ #ifdef PERL_HASH_INTERNAL_ACCESS #define PERL_HASH_INTERNAL(hash,str,len) PERL_HASH(hash,str,len) #endif /*----------------------------------------------------------------------------- * Endianess, misalignment capabilities and util macros * * The following 3 macros are defined in this section. The other macros defined * are only needed to help derive these 3. * * U8TO32_LE(x) Read a little endian unsigned 32-bit int * UNALIGNED_SAFE Defined if unaligned access is safe * ROTL32(x,r) Rotate x left by r bits */ #if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \ || defined(_MSC_VER) || defined (__TURBOC__) #define U8TO16_LE(d) (*((const U16 *) (d))) #endif #if !defined (U8TO16_LE) #define U8TO16_LE(d) ((((const U8 *)(d))[1] << 8)\ +((const U8 *)(d))[0]) #endif #if (BYTEORDER == 0x1234 || BYTEORDER == 0x12345678) && U32SIZE == 4 /* CPU endian matches murmurhash algorithm, so read 32-bit word directly */ #define U8TO32_LE(ptr) (*((const U32*)(ptr))) #elif BYTEORDER == 0x4321 || BYTEORDER == 0x87654321 /* TODO: Add additional cases below where a compiler provided bswap32 is available */ #if defined(__GNUC__) && (__GNUC__>4 || (__GNUC__==4 && __GNUC_MINOR__>=3)) #define U8TO32_LE(ptr) (__builtin_bswap32(*((U32*)(ptr)))) #else /* Without a known fast bswap32 we're just as well off doing this */ #define U8TO32_LE(ptr) (ptr[0]|ptr[1]<<8|ptr[2]<<16|ptr[3]<<24) #define UNALIGNED_SAFE #endif #else /* Unknown endianess so last resort is to read individual bytes */ #define U8TO32_LE(ptr) (ptr[0]|ptr[1]<<8|ptr[2]<<16|ptr[3]<<24) /* Since we're not doing word-reads we can skip the messing about with realignment */ #define UNALIGNED_SAFE #endif #ifdef HAS_QUAD #ifndef U64TYPE /* This probably isn't going to work, but failing with a compiler error due to lack of uint64_t is no worse than failing right now with an #error. */ #define U64 uint64_t #endif #endif /* Find best way to ROTL32/ROTL64 */ #if defined(_MSC_VER) #include <stdlib.h> /* Microsoft put _rotl declaration in here */ #define ROTL32(x,r) _rotl(x,r) #ifdef HAS_QUAD #define ROTL64(x,r) _rotl64(x,r) #endif #else /* gcc recognises this code and generates a rotate instruction for CPUs with one */ #define ROTL32(x,r) (((U32)x << r) | ((U32)x >> (32 - r))) #ifdef HAS_QUAD #define ROTL64(x,r) (((U64)x << r) | ((U64)x >> (64 - r))) #endif #endif #ifdef UV_IS_QUAD #define ROTL_UV(x,r) ROTL64(x,r) #else #define ROTL_UV(x,r) ROTL32(x,r) #endif /* This is SipHash by Jean-Philippe Aumasson and Daniel J. Bernstein. * The authors claim it is relatively secure compared to the alternatives * and that performance wise it is a suitable hash for languages like Perl. * See: * * https://www.131002.net/siphash/ * * This implementation seems to perform slightly slower than one-at-a-time for * short keys, but degrades slower for longer keys. Murmur Hash outperforms it * regardless of keys size. * * It is 64 bit only. */ #ifdef HAS_QUAD #define U8TO64_LE(p) \ (((U64)((p)[0]) ) | \ ((U64)((p)[1]) << 8) | \ ((U64)((p)[2]) << 16) | \ ((U64)((p)[3]) << 24) | \ ((U64)((p)[4]) << 32) | \ ((U64)((p)[5]) << 40) | \ ((U64)((p)[6]) << 48) | \ ((U64)((p)[7]) << 56)) #define SIPROUND \ STMT_START { \ v0 += v1; v1=ROTL64(v1,13); v1 ^= v0; v0=ROTL64(v0,32); \ v2 += v3; v3=ROTL64(v3,16); v3 ^= v2; \ v0 += v3; v3=ROTL64(v3,21); v3 ^= v0; \ v2 += v1; v1=ROTL64(v1,17); v1 ^= v2; v2=ROTL64(v2,32); \ } STMT_END /* SipHash-2-4 */ #define PERL_SIPHASH_FNC(FNC,SIP_ROUNDS,SIP_FINAL_ROUNDS) \ PERL_STATIC_INLINE U32 \ FNC(const unsigned char * const seed, const unsigned char *in, const STRLEN inlen) { \ /* "somepseudorandomlygeneratedbytes" */ \ U64 v0 = UINT64_C(0x736f6d6570736575); \ U64 v1 = UINT64_C(0x646f72616e646f6d); \ U64 v2 = UINT64_C(0x6c7967656e657261); \ U64 v3 = UINT64_C(0x7465646279746573); \ \ U64 b; \ U64 k0 = ((const U64*)seed)[0]; \ U64 k1 = ((const U64*)seed)[1]; \ U64 m; \ const int left = inlen & 7; \ const U8 *end = in + inlen - left; \ \ b = ( ( U64 )(inlen) ) << 56; \ v3 ^= k1; \ v2 ^= k0; \ v1 ^= k1; \ v0 ^= k0; \ \ for ( ; in != end; in += 8 ) \ { \ m = U8TO64_LE( in ); \ v3 ^= m; \ \ SIP_ROUNDS; \ \ v0 ^= m; \ } \ \ switch( left ) \ { \ case 7: b |= ( ( U64 )in[ 6] ) << 48; \ case 6: b |= ( ( U64 )in[ 5] ) << 40; \ case 5: b |= ( ( U64 )in[ 4] ) << 32; \ case 4: b |= ( ( U64 )in[ 3] ) << 24; \ case 3: b |= ( ( U64 )in[ 2] ) << 16; \ case 2: b |= ( ( U64 )in[ 1] ) << 8; \ case 1: b |= ( ( U64 )in[ 0] ); break; \ case 0: break; \ } \ \ v3 ^= b; \ \ SIP_ROUNDS; \ \ v0 ^= b; \ \ v2 ^= 0xff; \ \ SIP_FINAL_ROUNDS \ \ b = v0 ^ v1 ^ v2 ^ v3; \ return (U32)(b & U32_MAX); \ } PERL_SIPHASH_FNC( S_perl_hash_siphash_1_3 ,SIPROUND; ,SIPROUND;SIPROUND;SIPROUND; ) PERL_SIPHASH_FNC( S_perl_hash_siphash_2_4 ,SIPROUND;SIPROUND; ,SIPROUND;SIPROUND;SIPROUND;SIPROUND; ) #endif /* defined(HAS_QUAD) */ /* - ONE_AT_A_TIME_HARD is the 5.17+ recommend ONE_AT_A_TIME variant */ /* This is derived from the "One-at-a-Time" algorithm by Bob Jenkins * from requirements by Colin Plumb. * (http://burtleburtle.net/bob/hash/doobs.html) * Modified by Yves Orton to increase security for Perl 5.17 and later. */ PERL_STATIC_INLINE U32 S_perl_hash_one_at_a_time_hard(const unsigned char * const seed, const unsigned char *str, const STRLEN len) { const unsigned char * const end = (const unsigned char *)str + len; U32 hash = *((const U32*)seed) + (U32)len; while (str < end) { hash += (hash << 10); hash ^= (hash >> 6); hash += *str++; } hash += (hash << 10); hash ^= (hash >> 6); hash += seed[4]; hash += (hash << 10); hash ^= (hash >> 6); hash += seed[5]; hash += (hash << 10); hash ^= (hash >> 6); hash += seed[6]; hash += (hash << 10); hash ^= (hash >> 6); hash += seed[7]; hash += (hash << 10); hash ^= (hash >> 6); hash += (hash << 3); hash ^= (hash >> 11); return (hash + (hash << 15)); } #ifdef HAS_QUAD /* Hybrid hash function * * For short strings, 16 bytes or shorter, we use an optimised variant * of One At A Time Hard, and for longer strings, we use siphash_1_3. * * The optimisation of One At A Time Hard means we read the key in * reverse from normal, but by doing so we avoid the loop overhead. */ PERL_STATIC_INLINE U32 S_perl_hash_oaathu_siphash_1_3(const unsigned char * const seed, const unsigned char *str, const STRLEN len) { U32 hash = *((const U32*)seed) + (U32)len; switch (len) { case 16: hash += (hash << 10); hash ^= (hash >> 6); hash += str[15]; case 15: hash += (hash << 10); hash ^= (hash >> 6); hash += str[14]; case 14: hash += (hash << 10); hash ^= (hash >> 6); hash += str[13]; case 13: hash += (hash << 10); hash ^= (hash >> 6); hash += str[12]; case 12: hash += (hash << 10); hash ^= (hash >> 6); hash += str[11]; case 11: hash += (hash << 10); hash ^= (hash >> 6); hash += str[10]; case 10: hash += (hash << 10); hash ^= (hash >> 6); hash += str[9]; case 9: hash += (hash << 10); hash ^= (hash >> 6); hash += str[8]; case 8: hash += (hash << 10); hash ^= (hash >> 6); hash += str[7]; case 7: hash += (hash << 10); hash ^= (hash >> 6); hash += str[6]; case 6: hash += (hash << 10); hash ^= (hash >> 6); hash += str[5]; case 5: hash += (hash << 10); hash ^= (hash >> 6); hash += str[4]; case 4: hash += (hash << 10); hash ^= (hash >> 6); hash += str[3]; case 3: hash += (hash << 10); hash ^= (hash >> 6); hash += str[2]; case 2: hash += (hash << 10); hash ^= (hash >> 6); hash += str[1]; case 1: hash += (hash << 10); hash ^= (hash >> 6); hash += str[0]; case 0: hash += (hash << 10); hash ^= (hash >> 6); hash += seed[4]; hash += (hash << 10); hash ^= (hash >> 6); hash += seed[5]; hash += (hash << 10); hash ^= (hash >> 6); hash += seed[6]; hash += (hash << 10); hash ^= (hash >> 6); hash += seed[7]; hash += (hash << 10); hash ^= (hash >> 6); hash += (hash << 3); hash ^= (hash >> 11); return (hash + (hash << 15)); } return S_perl_hash_siphash_1_3(seed+8, str, len); } #endif /* defined(HAS_QUAD) */ #endif /*compile once*/ /* * ex: set ts=8 sts=4 sw=4 et: */
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