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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_SDBM) \
|| defined(PERL_HASH_FUNC_DJB2) \
|| defined(PERL_HASH_FUNC_SUPERFAST) \
|| defined(PERL_HASH_FUNC_MURMUR3) \
|| defined(PERL_HASH_FUNC_ONE_AT_A_TIME) \
|| defined(PERL_HASH_FUNC_ONE_AT_A_TIME_HARD) \
|| defined(PERL_HASH_FUNC_ONE_AT_A_TIME_OLD) \
)
#define PERL_HASH_FUNC_ONE_AT_A_TIME_HARD
#endif
#if defined(PERL_HASH_FUNC_SIPHASH)
# define PERL_HASH_FUNC "SIPHASH_2_4"
# define PERL_HASH_SEED_BYTES 16
# define PERL_HASH(hash,str,len) (hash)= S_perl_hash_siphash_2_4(PERL_HASH_SEED,(U8*)(str),(len))
#elif defined(PERL_HASH_FUNC_SUPERFAST)
# define PERL_HASH_FUNC "SUPERFAST"
# define PERL_HASH_SEED_BYTES 4
# define PERL_HASH(hash,str,len) (hash)= S_perl_hash_superfast(PERL_HASH_SEED,(U8*)(str),(len))
#elif defined(PERL_HASH_FUNC_MURMUR3)
# define PERL_HASH_FUNC "MURMUR3"
# define PERL_HASH_SEED_BYTES 4
# define PERL_HASH(hash,str,len) (hash)= S_perl_hash_murmur3(PERL_HASH_SEED,(U8*)(str),(len))
#elif defined(PERL_HASH_FUNC_DJB2)
# define PERL_HASH_FUNC "DJB2"
# define PERL_HASH_SEED_BYTES 4
# define PERL_HASH(hash,str,len) (hash)= S_perl_hash_djb2(PERL_HASH_SEED,(U8*)(str),(len))
#elif defined(PERL_HASH_FUNC_SDBM)
# define PERL_HASH_FUNC "SDBM"
# define PERL_HASH_SEED_BYTES 4
# define PERL_HASH(hash,str,len) (hash)= S_perl_hash_sdbm(PERL_HASH_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(hash,str,len) (hash)= S_perl_hash_one_at_a_time_hard(PERL_HASH_SEED,(U8*)(str),(len))
#elif defined(PERL_HASH_FUNC_ONE_AT_A_TIME)
# define PERL_HASH_FUNC "ONE_AT_A_TIME"
# define PERL_HASH_SEED_BYTES 4
# define PERL_HASH(hash,str,len) (hash)= S_perl_hash_one_at_a_time(PERL_HASH_SEED,(U8*)(str),(len))
#elif defined(PERL_HASH_FUNC_ONE_AT_A_TIME_OLD)
# define PERL_HASH_FUNC "ONE_AT_A_TIME_OLD"
# define PERL_HASH_SEED_BYTES 4
# define PERL_HASH(hash,str,len) (hash)= S_perl_hash_old_one_at_a_time(PERL_HASH_SEED,(U8*)(str),(len))
#endif
#ifndef PERL_HASH
#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 "PeRl"
# elif PERL_HASH_SEED_BYTES == 16
# define PERL_HASH_SEED "PeRlHaShhAcKpErl"
# else
# error "No PERL_HASH_SEED definition for " PERL_HASH_FUNC
# endif
#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 READ_UINT32 works on non-word boundaries
* 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
/* Now find best way we can to READ_UINT32 */
#if (BYTEORDER == 0x1234 || BYTEORDER == 0x12345678) && U32SIZE == 4
/* CPU endian matches murmurhash algorithm, so read 32-bit word directly */
#define U8TO32_LE(ptr) (*((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 U64TYPE 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) (((U64TYPE)x << r) | ((U64TYPE)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) \
(((U64TYPE)((p)[0]) ) | \
((U64TYPE)((p)[1]) << 8) | \
((U64TYPE)((p)[2]) << 16) | \
((U64TYPE)((p)[3]) << 24) | \
((U64TYPE)((p)[4]) << 32) | \
((U64TYPE)((p)[5]) << 40) | \
((U64TYPE)((p)[6]) << 48) | \
((U64TYPE)((p)[7]) << 56))
#define SIPROUND \
do { \
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); \
} while(0)
/* SipHash-2-4 */
PERL_STATIC_INLINE U32
S_perl_hash_siphash_2_4(const unsigned char * const seed, const unsigned char *in, const STRLEN inlen) {
/* "somepseudorandomlygeneratedbytes" */
U64TYPE v0 = 0x736f6d6570736575ULL;
U64TYPE v1 = 0x646f72616e646f6dULL;
U64TYPE v2 = 0x6c7967656e657261ULL;
U64TYPE v3 = 0x7465646279746573ULL;
U64TYPE b;
U64TYPE k0 = ((U64TYPE*)seed)[0];
U64TYPE k1 = ((U64TYPE*)seed)[1];
U64TYPE m;
const int left = inlen & 7;
const U8 *end = in + inlen - left;
b = ( ( U64TYPE )(inlen) ) << 56;
v3 ^= k1;
v2 ^= k0;
v1 ^= k1;
v0 ^= k0;
for ( ; in != end; in += 8 )
{
m = U8TO64_LE( in );
v3 ^= m;
SIPROUND;
SIPROUND;
v0 ^= m;
}
switch( left )
{
case 7: b |= ( ( U64TYPE )in[ 6] ) << 48;
case 6: b |= ( ( U64TYPE )in[ 5] ) << 40;
case 5: b |= ( ( U64TYPE )in[ 4] ) << 32;
case 4: b |= ( ( U64TYPE )in[ 3] ) << 24;
case 3: b |= ( ( U64TYPE )in[ 2] ) << 16;
case 2: b |= ( ( U64TYPE )in[ 1] ) << 8;
case 1: b |= ( ( U64TYPE )in[ 0] ); break;
case 0: break;
}
v3 ^= b;
SIPROUND;
SIPROUND;
v0 ^= b;
v2 ^= 0xff;
SIPROUND;
SIPROUND;
SIPROUND;
SIPROUND;
b = v0 ^ v1 ^ v2 ^ v3;
return (U32)(b & U32_MAX);
}
#endif /* defined(HAS_QUAD) */
/* FYI: This is the "Super-Fast" algorithm mentioned by Bob Jenkins in
* (http://burtleburtle.net/bob/hash/doobs.html)
* It is by Paul Hsieh (c) 2004 and is analysed here
* http://www.azillionmonkeys.com/qed/hash.html
* license terms are here:
* http://www.azillionmonkeys.com/qed/weblicense.html
*/
PERL_STATIC_INLINE U32
S_perl_hash_superfast(const unsigned char * const seed, const unsigned char *str, STRLEN len) {
U32 hash = *((U32*)seed) + len;
U32 tmp;
int rem= len & 3;
len >>= 2;
for (;len > 0; len--) {
hash += U8TO16_LE (str);
tmp = (U8TO16_LE (str+2) << 11) ^ hash;
hash = (hash << 16) ^ tmp;
str += 2 * sizeof (U16);
hash += hash >> 11;
}
/* Handle end cases */
switch (rem) { \
case 3: hash += U8TO16_LE (str);
hash ^= hash << 16;
hash ^= str[sizeof (U16)] << 18;
hash += hash >> 11;
break;
case 2: hash += U8TO16_LE (str);
hash ^= hash << 11;
hash += hash >> 17;
break;
case 1: hash += *str;
hash ^= hash << 10;
hash += hash >> 1;
}
/* Force "avalanching" of final 127 bits */
hash ^= hash << 3;
hash += hash >> 5;
hash ^= hash << 4;
hash += hash >> 17;
hash ^= hash << 25;
return (hash + (hash >> 6));
}
/*-----------------------------------------------------------------------------
* MurmurHash3 was written by Austin Appleby, and is placed in the public
* domain.
*
* This implementation was originally written by Shane Day, and is also public domain,
* and was modified to function as a macro similar to other perl hash functions by
* Yves Orton.
*
* This is a portable ANSI C implementation of MurmurHash3_x86_32 (Murmur3A)
* with support for progressive processing.
*
* If you want to understand the MurmurHash algorithm you would be much better
* off reading the original source. Just point your browser at:
* http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
*
* How does it work?
*
* We can only process entire 32 bit chunks of input, except for the very end
* that may be shorter.
*
* To handle endianess I simply use a macro that reads a U32 and define
* that macro to be a direct read on little endian machines, a read and swap
* on big endian machines, or a byte-by-byte read if the endianess is unknown.
*/
/*-----------------------------------------------------------------------------
* Core murmurhash algorithm macros */
#define MURMUR_C1 (0xcc9e2d51)
#define MURMUR_C2 (0x1b873593)
#define MURMUR_C3 (0xe6546b64)
#define MURMUR_C4 (0x85ebca6b)
#define MURMUR_C5 (0xc2b2ae35)
/* This is the main processing body of the algorithm. It operates
* on each full 32-bits of input. */
#define MURMUR_DOBLOCK(h1, k1) STMT_START { \
k1 *= MURMUR_C1; \
k1 = ROTL32(k1,15); \
k1 *= MURMUR_C2; \
\
h1 ^= k1; \
h1 = ROTL32(h1,13); \
h1 = h1 * 5 + MURMUR_C3; \
} STMT_END
/* Append unaligned bytes to carry, forcing hash churn if we have 4 bytes */
/* cnt=bytes to process, h1=name of h1 var, c=carry, n=bytes in c, ptr/len=payload */
#define MURMUR_DOBYTES(cnt, h1, c, n, ptr, len) STMT_START { \
int MURMUR_DOBYTES_i = cnt; \
while(MURMUR_DOBYTES_i--) { \
c = c>>8 | *ptr++<<24; \
n++; len--; \
if(n==4) { \
MURMUR_DOBLOCK(h1, c); \
n = 0; \
} \
} \
} STMT_END
/* now we create the hash function */
PERL_STATIC_INLINE U32
S_perl_hash_murmur3(const unsigned char * const seed, const unsigned char *ptr, STRLEN len) {
U32 h1 = *((U32*)seed);
U32 k1;
U32 carry = 0;
const unsigned char *end;
int bytes_in_carry = 0; /* bytes in carry */
I32 total_length= len;
#if defined(UNALIGNED_SAFE)
/* Handle carry: commented out as its only used in incremental mode - it never fires for us
int i = (4-n) & 3;
if(i && i <= len) {
MURMUR_DOBYTES(i, h1, carry, bytes_in_carry, ptr, len);
}
*/
/* This CPU handles unaligned word access */
/* Process 32-bit chunks */
end = ptr + len/4*4;
for( ; ptr < end ; ptr+=4) {
k1 = U8TO32_LE(ptr);
MURMUR_DOBLOCK(h1, k1);
}
#else
/* This CPU does not handle unaligned word access */
/* Consume enough so that the next data byte is word aligned */
STRLEN i = -PTR2IV(ptr) & 3;
if(i && i <= len) {
MURMUR_DOBYTES(i, h1, carry, bytes_in_carry, ptr, len);
}
/* We're now aligned. Process in aligned blocks. Specialise for each possible carry count */
end = ptr + len/4*4;
switch(bytes_in_carry) { /* how many bytes in carry */
case 0: /* c=[----] w=[3210] b=[3210]=w c'=[----] */
for( ; ptr < end ; ptr+=4) {
k1 = U8TO32_LE(ptr);
MURMUR_DOBLOCK(h1, k1);
}
break;
case 1: /* c=[0---] w=[4321] b=[3210]=c>>24|w<<8 c'=[4---] */
for( ; ptr < end ; ptr+=4) {
k1 = carry>>24;
carry = U8TO32_LE(ptr);
k1 |= carry<<8;
MURMUR_DOBLOCK(h1, k1);
}
break;
case 2: /* c=[10--] w=[5432] b=[3210]=c>>16|w<<16 c'=[54--] */
for( ; ptr < end ; ptr+=4) {
k1 = carry>>16;
carry = U8TO32_LE(ptr);
k1 |= carry<<16;
MURMUR_DOBLOCK(h1, k1);
}
break;
case 3: /* c=[210-] w=[6543] b=[3210]=c>>8|w<<24 c'=[654-] */
for( ; ptr < end ; ptr+=4) {
k1 = carry>>8;
carry = U8TO32_LE(ptr);
k1 |= carry<<24;
MURMUR_DOBLOCK(h1, k1);
}
}
#endif
/* Advance over whole 32-bit chunks, possibly leaving 1..3 bytes */
len -= len/4*4;
/* Append any remaining bytes into carry */
MURMUR_DOBYTES(len, h1, carry, bytes_in_carry, ptr, len);
if (bytes_in_carry) {
k1 = carry >> ( 4 - bytes_in_carry ) * 8;
k1 *= MURMUR_C1;
k1 = ROTL32(k1,15);
k1 *= MURMUR_C2;
h1 ^= k1;
}
h1 ^= total_length;
/* fmix */
h1 ^= h1 >> 16;
h1 *= MURMUR_C4;
h1 ^= h1 >> 13;
h1 *= MURMUR_C5;
h1 ^= h1 >> 16;
return h1;
}
PERL_STATIC_INLINE U32
S_perl_hash_djb2(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
const unsigned char * const end = (const unsigned char *)str + len;
U32 hash = *((U32*)seed + len);
while (str < end) {
hash = ((hash << 5) + hash) + *str++;
}
return hash;
}
PERL_STATIC_INLINE U32
S_perl_hash_sdbm(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
const unsigned char * const end = (const unsigned char *)str + len;
U32 hash = *((U32*)seed + len);
while (str < end) {
hash = (hash << 6) + (hash << 16) - hash + *str++;
}
return hash;
}
/* - ONE_AT_A_TIME_HARD is the 5.17+ recommend ONE_AT_A_TIME algorithm
* - ONE_AT_A_TIME_OLD is the unmodified 5.16 and older algorithm
* - ONE_AT_A_TIME is a 5.17+ tweak of ONE_AT_A_TIME_OLD to
* prevent strings of only \0 but different lengths from colliding
*
* Security-wise, from best to worst,
* ONE_AT_A_TIME_HARD > ONE_AT_A_TIME > ONE_AT_A_TIME_OLD
* There is a big drop-off in security between ONE_AT_A_TIME_HARD and
* ONE_AT_A_TIME
* */
/* This is the "One-at-a-Time" algorithm by Bob Jenkins
* from requirements by Colin Plumb.
* (http://burtleburtle.net/bob/hash/doobs.html)
* With seed/len tweak.
* */
PERL_STATIC_INLINE U32
S_perl_hash_one_at_a_time(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
const unsigned char * const end = (const unsigned char *)str + len;
U32 hash = *((U32*)seed) + len;
while (str < end) {
hash += *str++;
hash += (hash << 10);
hash ^= (hash >> 6);
}
hash += (hash << 3);
hash ^= (hash >> 11);
return (hash + (hash << 15));
}
/* Derived from "One-at-a-Time" algorithm by Bob Jenkins */
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 = *((U32*)seed) + 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));
}
PERL_STATIC_INLINE U32
S_perl_hash_old_one_at_a_time(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
const unsigned char * const end = (const unsigned char *)str + len;
U32 hash = *((U32*)seed);
while (str < end) {
hash += *str++;
hash += (hash << 10);
hash ^= (hash >> 6);
}
hash += (hash << 3);
hash ^= (hash >> 11);
return (hash + (hash << 15));
}
/* 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
#endif /*compile once*/
/*
* Local variables:
* c-indentation-style: bsd
* c-basic-offset: 4
* indent-tabs-mode: nil
* End:
*
* ex: set ts=8 sts=4 sw=4 et:
*/
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