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fixup pod in Porting/bench.pl
[perl5.git] / hv_func.h
CommitLineData
4d3a042d
YO		 1/* hash a key
2 *--------------------------------------------------------------------------------------
3 * The "hash seed" feature was added in Perl 5.8.1 to perturb the results
4 * to avoid "algorithmic complexity attacks".
5 *
6 * If USE_HASH_SEED is defined, hash randomisation is done by default
7 * If USE_HASH_SEED_EXPLICIT is defined, hash randomisation is done
8 * only if the environment variable PERL_HASH_SEED is set.
9 * (see also perl.c:perl_parse() and S_init_tls_and_interp() and util.c:get_hash_seed())
10 */
11
12#ifndef PERL_SEEN_HV_FUNC_H /* compile once */
13#define PERL_SEEN_HV_FUNC_H
14
15#if !( 0 \
e6b54db6 16 || defined(PERL_HASH_FUNC_SIPHASH) \
6b026047
YO		 17 || defined(PERL_HASH_FUNC_SIPHASH13) \
18 || defined(PERL_HASH_FUNC_HYBRID_OAATHU_SIPHASH13) \
4d3a042d
YO		 19 || defined(PERL_HASH_FUNC_SDBM) \
20 || defined(PERL_HASH_FUNC_DJB2) \
21 || defined(PERL_HASH_FUNC_SUPERFAST) \
22 || defined(PERL_HASH_FUNC_MURMUR3) \
23 || defined(PERL_HASH_FUNC_ONE_AT_A_TIME) \
b1300a73 24 || defined(PERL_HASH_FUNC_ONE_AT_A_TIME_HARD) \
4d3a042d 25 || defined(PERL_HASH_FUNC_ONE_AT_A_TIME_OLD) \
7e0dd61b
YO		 26 || defined(PERL_HASH_FUNC_MURMUR_HASH_64A) \
27 || defined(PERL_HASH_FUNC_MURMUR_HASH_64B) \
4d3a042d 28 )
6b026047
YO		 29#ifdef HAS_QUAD
30#define PERL_HASH_FUNC_HYBRID_OAATHU_SIPHASH13
31#else
b1300a73 32#define PERL_HASH_FUNC_ONE_AT_A_TIME_HARD
4d3a042d 33#endif
6b026047 34#endif
4d3a042d
YO		 35
36#if defined(PERL_HASH_FUNC_SIPHASH)
37# define PERL_HASH_FUNC "SIPHASH_2_4"
38# define PERL_HASH_SEED_BYTES 16
3d53a8ea 39# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_siphash_2_4((seed),(U8*)(str),(len))
6b026047
YO		 40#elif defined(PERL_HASH_FUNC_SIPHASH13)
41# define PERL_HASH_FUNC "SIPHASH_1_3"
42# define PERL_HASH_SEED_BYTES 16
43# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_siphash_1_3((seed),(U8*)(str),(len))
44#elif defined(PERL_HASH_FUNC_HYBRID_OAATHU_SIPHASH13)
45# define PERL_HASH_FUNC "HYBRID_OAATHU_SIPHASH_1_3"
46# define PERL_HASH_SEED_BYTES 24
47# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_oaathu_siphash_1_3((seed),(U8*)(str),(len))
4d3a042d
YO		 48#elif defined(PERL_HASH_FUNC_SUPERFAST)
49# define PERL_HASH_FUNC "SUPERFAST"
50# define PERL_HASH_SEED_BYTES 4
3d53a8ea 51# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_superfast((seed),(U8*)(str),(len))
4d3a042d
YO		 52#elif defined(PERL_HASH_FUNC_MURMUR3)
53# define PERL_HASH_FUNC "MURMUR3"
54# define PERL_HASH_SEED_BYTES 4
3d53a8ea 55# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_murmur3((seed),(U8*)(str),(len))
4d3a042d
YO		 56#elif defined(PERL_HASH_FUNC_DJB2)
57# define PERL_HASH_FUNC "DJB2"
58# define PERL_HASH_SEED_BYTES 4
3d53a8ea 59# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_djb2((seed),(U8*)(str),(len))
4d3a042d
YO		 60#elif defined(PERL_HASH_FUNC_SDBM)
61# define PERL_HASH_FUNC "SDBM"
62# define PERL_HASH_SEED_BYTES 4
3d53a8ea 63# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_sdbm((seed),(U8*)(str),(len))
b1300a73
YO		 64#elif defined(PERL_HASH_FUNC_ONE_AT_A_TIME_HARD)
65# define PERL_HASH_FUNC "ONE_AT_A_TIME_HARD"
66# define PERL_HASH_SEED_BYTES 8
3d53a8ea 67# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_one_at_a_time_hard((seed),(U8*)(str),(len))
4d3a042d
YO		 68#elif defined(PERL_HASH_FUNC_ONE_AT_A_TIME)
69# define PERL_HASH_FUNC "ONE_AT_A_TIME"
70# define PERL_HASH_SEED_BYTES 4
3d53a8ea 71# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_one_at_a_time((seed),(U8*)(str),(len))
4d3a042d
YO		 72#elif defined(PERL_HASH_FUNC_ONE_AT_A_TIME_OLD)
73# define PERL_HASH_FUNC "ONE_AT_A_TIME_OLD"
74# define PERL_HASH_SEED_BYTES 4
3d53a8ea 75# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_old_one_at_a_time((seed),(U8*)(str),(len))
7e0dd61b
YO		 76#elif defined(PERL_HASH_FUNC_MURMUR_HASH_64A)
77# define PERL_HASH_FUNC "MURMUR_HASH_64A"
78# define PERL_HASH_SEED_BYTES 8
79# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_murmur_hash_64a((seed),(U8*)(str),(len))
80#elif defined(PERL_HASH_FUNC_MURMUR_HASH_64B)
81# define PERL_HASH_FUNC "MURMUR_HASH_64B"
82# define PERL_HASH_SEED_BYTES 8
83# define PERL_HASH_WITH_SEED(seed,hash,str,len) (hash)= S_perl_hash_murmur_hash_64b((seed),(U8*)(str),(len))
4d3a042d
YO		 84#endif
85
3d53a8ea 86#ifndef PERL_HASH_WITH_SEED
4d3a042d
YO		 87#error "No hash function defined!"
88#endif
89#ifndef PERL_HASH_SEED_BYTES
90#error "PERL_HASH_SEED_BYTES not defined"
91#endif
92#ifndef PERL_HASH_FUNC
93#error "PERL_HASH_FUNC not defined"
94#endif
95
96#ifndef PERL_HASH_SEED
97# if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT)
98# define PERL_HASH_SEED PL_hash_seed
99# elif PERL_HASH_SEED_BYTES == 4
25c1b134 100# define PERL_HASH_SEED ((const U8 *)"PeRl")
c2d4ebc6 101# elif PERL_HASH_SEED_BYTES == 8
25c1b134 102# define PERL_HASH_SEED ((const U8 *)"PeRlHaSh")
4d3a042d 103# elif PERL_HASH_SEED_BYTES == 16
25c1b134 104# define PERL_HASH_SEED ((const U8 *)"PeRlHaShhAcKpErl")
4d3a042d
YO		 105# else
106# error "No PERL_HASH_SEED definition for " PERL_HASH_FUNC
107# endif
108#endif
109
3d53a8ea
YO		 110#define PERL_HASH(hash,str,len) PERL_HASH_WITH_SEED(PERL_HASH_SEED,hash,str,len)
111
4d3a042d
YO		 112/*-----------------------------------------------------------------------------
113 * Endianess, misalignment capabilities and util macros
114 *
115 * The following 3 macros are defined in this section. The other macros defined
116 * are only needed to help derive these 3.
117 *
118 * U8TO32_LE(x) Read a little endian unsigned 32-bit int
8757ed9b 119 * UNALIGNED_SAFE Defined if unaligned access is safe
4d3a042d
YO		 120 * ROTL32(x,r) Rotate x left by r bits
121 */
122
123#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \
0a35fd8a 124 || defined(_MSC_VER) || defined (__TURBOC__)
4d3a042d
YO		 125#define U8TO16_LE(d) (*((const U16 *) (d)))
126#endif
127
128#if !defined (U8TO16_LE)
129#define U8TO16_LE(d) ((((const U8 *)(d))[1] << 8)\
130 +((const U8 *)(d))[0])
131#endif
132
4d3a042d
YO		 133#if (BYTEORDER == 0x1234 || BYTEORDER == 0x12345678) && U32SIZE == 4
134 /* CPU endian matches murmurhash algorithm, so read 32-bit word directly */
463ddf34 135 #define U8TO32_LE(ptr) (*((const U32*)(ptr)))
4d3a042d
YO		 136#elif BYTEORDER == 0x4321 || BYTEORDER == 0x87654321
137 /* TODO: Add additional cases below where a compiler provided bswap32 is available */
138 #if defined(__GNUC__) && (__GNUC__>4 || (__GNUC__==4 && __GNUC_MINOR__>=3))
139 #define U8TO32_LE(ptr) (__builtin_bswap32(*((U32*)(ptr))))
140 #else
141 /* Without a known fast bswap32 we're just as well off doing this */
142 #define U8TO32_LE(ptr) (ptr[0]|ptr[1]<<8|ptr[2]<<16|ptr[3]<<24)
143 #define UNALIGNED_SAFE
144 #endif
145#else
146 /* Unknown endianess so last resort is to read individual bytes */
147 #define U8TO32_LE(ptr) (ptr[0]|ptr[1]<<8|ptr[2]<<16|ptr[3]<<24)
148 /* Since we're not doing word-reads we can skip the messing about with realignment */
149 #define UNALIGNED_SAFE
150#endif
151
b716320d
YO		 152#ifdef HAS_QUAD
153#ifndef U64TYPE
154/* This probably isn't going to work, but failing with a compiler error due to
155 lack of uint64_t is no worse than failing right now with an #error. */
702c92eb 156#define U64 uint64_t
b716320d
YO		 157#endif
158#endif
159
160/* Find best way to ROTL32/ROTL64 */
4d3a042d
YO		 161#if defined(_MSC_VER)
162 #include <stdlib.h> /* Microsoft put _rotl declaration in here */
163 #define ROTL32(x,r) _rotl(x,r)
b716320d
YO		 164 #ifdef HAS_QUAD
165 #define ROTL64(x,r) _rotl64(x,r)
166 #endif
4d3a042d
YO		 167#else
168 /* gcc recognises this code and generates a rotate instruction for CPUs with one */
169 #define ROTL32(x,r) (((U32)x << r) | ((U32)x >> (32 - r)))
b716320d 170 #ifdef HAS_QUAD
702c92eb 171 #define ROTL64(x,r) (((U64)x << r) | ((U64)x >> (64 - r)))
b716320d 172 #endif
4d3a042d
YO		 173#endif
174
175
b716320d
YO		 176#ifdef UV_IS_QUAD
177#define ROTL_UV(x,r) ROTL64(x,r)
178#else
179#define ROTL_UV(x,r) ROTL32(x,r)
180#endif
181
4d3a042d
YO		 182/* This is SipHash by Jean-Philippe Aumasson and Daniel J. Bernstein.
183 * The authors claim it is relatively secure compared to the alternatives
184 * and that performance wise it is a suitable hash for languages like Perl.
185 * See:
186 *
187 * https://www.131002.net/siphash/
188 *
189 * This implementation seems to perform slightly slower than one-at-a-time for
190 * short keys, but degrades slower for longer keys. Murmur Hash outperforms it
191 * regardless of keys size.
192 *
193 * It is 64 bit only.
194 */
195
196#ifdef HAS_QUAD
197
4d3a042d 198#define U8TO64_LE(p) \
702c92eb
JH		 199 (((U64)((p)[0]) ) | \
200 ((U64)((p)[1]) << 8) | \
201 ((U64)((p)[2]) << 16) | \
202 ((U64)((p)[3]) << 24) | \
203 ((U64)((p)[4]) << 32) | \
204 ((U64)((p)[5]) << 40) | \
205 ((U64)((p)[6]) << 48) | \
206 ((U64)((p)[7]) << 56))
4d3a042d
YO		 207
208#define SIPROUND \
6b026047 209 STMT_START { \
4d3a042d
YO		 210 v0 += v1; v1=ROTL64(v1,13); v1 ^= v0; v0=ROTL64(v0,32); \
211 v2 += v3; v3=ROTL64(v3,16); v3 ^= v2; \
212 v0 += v3; v3=ROTL64(v3,21); v3 ^= v0; \
213 v2 += v1; v1=ROTL64(v1,17); v1 ^= v2; v2=ROTL64(v2,32); \
6b026047 214 } STMT_END
4d3a042d
YO		 215
216/* SipHash-2-4 */
217
6b026047
YO		 218
219#define PERL_SIPHASH_FNC(FNC,SIP_ROUNDS,SIP_FINAL_ROUNDS) \
220PERL_STATIC_INLINE U32 \
221FNC(const unsigned char * const seed, const unsigned char *in, const STRLEN inlen) { \
222 /* "somepseudorandomlygeneratedbytes" */ \
223 U64 v0 = UINT64_C(0x736f6d6570736575); \
224 U64 v1 = UINT64_C(0x646f72616e646f6d); \
225 U64 v2 = UINT64_C(0x6c7967656e657261); \
226 U64 v3 = UINT64_C(0x7465646279746573); \
227 \
228 U64 b; \
229 U64 k0 = ((const U64*)seed)[0]; \
230 U64 k1 = ((const U64*)seed)[1]; \
231 U64 m; \
232 const int left = inlen & 7; \
233 const U8 *end = in + inlen - left; \
234 \
235 b = ( ( U64 )(inlen) ) << 56; \
236 v3 ^= k1; \
237 v2 ^= k0; \
238 v1 ^= k1; \
239 v0 ^= k0; \
240 \
241 for ( ; in != end; in += 8 ) \
242 { \
243 m = U8TO64_LE( in ); \
244 v3 ^= m; \
245 \
246 SIP_ROUNDS; \
247 \
248 v0 ^= m; \
249 } \
250 \
251 switch( left ) \
252 { \
253 case 7: b |= ( ( U64 )in[ 6] ) << 48; \
254 case 6: b |= ( ( U64 )in[ 5] ) << 40; \
255 case 5: b |= ( ( U64 )in[ 4] ) << 32; \
256 case 4: b |= ( ( U64 )in[ 3] ) << 24; \
257 case 3: b |= ( ( U64 )in[ 2] ) << 16; \
258 case 2: b |= ( ( U64 )in[ 1] ) << 8; \
259 case 1: b |= ( ( U64 )in[ 0] ); break; \
260 case 0: break; \
261 } \
262 \
263 v3 ^= b; \
264 \
265 SIP_ROUNDS; \
266 \
267 v0 ^= b; \
268 \
269 v2 ^= 0xff; \
270 \
271 SIP_FINAL_ROUNDS \
272 \
273 b = v0 ^ v1 ^ v2 ^ v3; \
274 return (U32)(b & U32_MAX); \
4d3a042d 275}
6b026047
YO		 276
277PERL_SIPHASH_FNC(
278 S_perl_hash_siphash_1_3
279 ,SIPROUND;
280 ,SIPROUND;SIPROUND;SIPROUND;
281)
282
283PERL_SIPHASH_FNC(
284 S_perl_hash_siphash_2_4
285 ,SIPROUND;SIPROUND;
286 ,SIPROUND;SIPROUND;SIPROUND;SIPROUND;
287)
288
4d3a042d
YO		 289#endif /* defined(HAS_QUAD) */
290
6b026047 291
4d3a042d
YO		 292/* FYI: This is the "Super-Fast" algorithm mentioned by Bob Jenkins in
293 * (http://burtleburtle.net/bob/hash/doobs.html)
294 * It is by Paul Hsieh (c) 2004 and is analysed here
295 * http://www.azillionmonkeys.com/qed/hash.html
296 * license terms are here:
297 * http://www.azillionmonkeys.com/qed/weblicense.html
298 */
299
3efdcc9c 300
4d3a042d
YO		 301PERL_STATIC_INLINE U32
302S_perl_hash_superfast(const unsigned char * const seed, const unsigned char *str, STRLEN len) {
463ddf34 303 U32 hash = *((const U32*)seed) + (U32)len;
4d3a042d
YO		 304 U32 tmp;
305 int rem= len & 3;
306 len >>= 2;
307
308 for (;len > 0; len--) {
309 hash += U8TO16_LE (str);
310 tmp = (U8TO16_LE (str+2) << 11) ^ hash;
311 hash = (hash << 16) ^ tmp;
312 str += 2 * sizeof (U16);
313 hash += hash >> 11;
314 }
315
316 /* Handle end cases */
317 switch (rem) { \
318 case 3: hash += U8TO16_LE (str);
319 hash ^= hash << 16;
320 hash ^= str[sizeof (U16)] << 18;
321 hash += hash >> 11;
322 break;
323 case 2: hash += U8TO16_LE (str);
324 hash ^= hash << 11;
325 hash += hash >> 17;
326 break;
327 case 1: hash += *str;
328 hash ^= hash << 10;
329 hash += hash >> 1;
330 }
331 /* Force "avalanching" of final 127 bits */
332 hash ^= hash << 3;
333 hash += hash >> 5;
334 hash ^= hash << 4;
335 hash += hash >> 17;
336 hash ^= hash << 25;
337 return (hash + (hash >> 6));
338}
3efdcc9c 339
4d3a042d
YO		 340
341/*-----------------------------------------------------------------------------
342 * MurmurHash3 was written by Austin Appleby, and is placed in the public
343 * domain.
344 *
345 * This implementation was originally written by Shane Day, and is also public domain,
346 * and was modified to function as a macro similar to other perl hash functions by
347 * Yves Orton.
348 *
349 * This is a portable ANSI C implementation of MurmurHash3_x86_32 (Murmur3A)
350 * with support for progressive processing.
351 *
352 * If you want to understand the MurmurHash algorithm you would be much better
353 * off reading the original source. Just point your browser at:
354 * http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
355 *
356 * How does it work?
357 *
358 * We can only process entire 32 bit chunks of input, except for the very end
359 * that may be shorter.
360 *
361 * To handle endianess I simply use a macro that reads a U32 and define
362 * that macro to be a direct read on little endian machines, a read and swap
363 * on big endian machines, or a byte-by-byte read if the endianess is unknown.
364 */
365
3efdcc9c 366
4d3a042d
YO		 367/*-----------------------------------------------------------------------------
368 * Core murmurhash algorithm macros */
369
370#define MURMUR_C1 (0xcc9e2d51)
371#define MURMUR_C2 (0x1b873593)
372#define MURMUR_C3 (0xe6546b64)
373#define MURMUR_C4 (0x85ebca6b)
374#define MURMUR_C5 (0xc2b2ae35)
375
376/* This is the main processing body of the algorithm. It operates
377 * on each full 32-bits of input. */
378#define MURMUR_DOBLOCK(h1, k1) STMT_START { \
379 k1 *= MURMUR_C1; \
380 k1 = ROTL32(k1,15); \
381 k1 *= MURMUR_C2; \
382 \
383 h1 ^= k1; \
384 h1 = ROTL32(h1,13); \
385 h1 = h1 * 5 + MURMUR_C3; \
386} STMT_END
387
388
389/* Append unaligned bytes to carry, forcing hash churn if we have 4 bytes */
390/* cnt=bytes to process, h1=name of h1 var, c=carry, n=bytes in c, ptr/len=payload */
391#define MURMUR_DOBYTES(cnt, h1, c, n, ptr, len) STMT_START { \
392 int MURMUR_DOBYTES_i = cnt; \
393 while(MURMUR_DOBYTES_i--) { \
394 c = c>>8 | *ptr++<<24; \
395 n++; len--; \
396 if(n==4) { \
397 MURMUR_DOBLOCK(h1, c); \
398 n = 0; \
399 } \
400 } \
401} STMT_END
402
403
404/* now we create the hash function */
405PERL_STATIC_INLINE U32
406S_perl_hash_murmur3(const unsigned char * const seed, const unsigned char *ptr, STRLEN len) {
463ddf34 407 U32 h1 = *((const U32*)seed);
4d3a042d
YO		 408 U32 k1;
409 U32 carry = 0;
410
411 const unsigned char *end;
412 int bytes_in_carry = 0; /* bytes in carry */
b4045391 413 I32 total_length= (I32)len;
4d3a042d
YO		 414
415#if defined(UNALIGNED_SAFE)
416 /* Handle carry: commented out as its only used in incremental mode - it never fires for us
417 int i = (4-n) & 3;
418 if(i && i <= len) {
419 MURMUR_DOBYTES(i, h1, carry, bytes_in_carry, ptr, len);
420 }
421 */
422
423 /* This CPU handles unaligned word access */
424 /* Process 32-bit chunks */
425 end = ptr + len/4*4;
426 for( ; ptr < end ; ptr+=4) {
427 k1 = U8TO32_LE(ptr);
428 MURMUR_DOBLOCK(h1, k1);
429 }
430#else
431 /* This CPU does not handle unaligned word access */
432
433 /* Consume enough so that the next data byte is word aligned */
c8523631
RB		 434 STRLEN i = -PTR2IV(ptr) & 3;
435 if(i && i <= len) {
b4045391 436 MURMUR_DOBYTES((int)i, h1, carry, bytes_in_carry, ptr, len);
4d3a042d
YO		 437 }
438
439 /* We're now aligned. Process in aligned blocks. Specialise for each possible carry count */
440 end = ptr + len/4*4;
441 switch(bytes_in_carry) { /* how many bytes in carry */
442 case 0: /* c=[----] w=[3210] b=[3210]=w c'=[----] */
443 for( ; ptr < end ; ptr+=4) {
444 k1 = U8TO32_LE(ptr);
445 MURMUR_DOBLOCK(h1, k1);
446 }
447 break;
448 case 1: /* c=[0---] w=[4321] b=[3210]=c>>24|w<<8 c'=[4---] */
449 for( ; ptr < end ; ptr+=4) {
450 k1 = carry>>24;
451 carry = U8TO32_LE(ptr);
452 k1 |= carry<<8;
453 MURMUR_DOBLOCK(h1, k1);
454 }
455 break;
456 case 2: /* c=[10--] w=[5432] b=[3210]=c>>16|w<<16 c'=[54--] */
457 for( ; ptr < end ; ptr+=4) {
458 k1 = carry>>16;
459 carry = U8TO32_LE(ptr);
460 k1 |= carry<<16;
461 MURMUR_DOBLOCK(h1, k1);
462 }
463 break;
464 case 3: /* c=[210-] w=[6543] b=[3210]=c>>8|w<<24 c'=[654-] */
465 for( ; ptr < end ; ptr+=4) {
466 k1 = carry>>8;
467 carry = U8TO32_LE(ptr);
468 k1 |= carry<<24;
469 MURMUR_DOBLOCK(h1, k1);
470 }
471 }
472#endif
473 /* Advance over whole 32-bit chunks, possibly leaving 1..3 bytes */
474 len -= len/4*4;
475
476 /* Append any remaining bytes into carry */
b4045391 477 MURMUR_DOBYTES((int)len, h1, carry, bytes_in_carry, ptr, len);
4d3a042d
YO		 478
479 if (bytes_in_carry) {
480 k1 = carry >> ( 4 - bytes_in_carry ) * 8;
481 k1 *= MURMUR_C1;
482 k1 = ROTL32(k1,15);
483 k1 *= MURMUR_C2;
484 h1 ^= k1;
485 }
486 h1 ^= total_length;
487
488 /* fmix */
489 h1 ^= h1 >> 16;
490 h1 *= MURMUR_C4;
491 h1 ^= h1 >> 13;
492 h1 *= MURMUR_C5;
493 h1 ^= h1 >> 16;
494 return h1;
495}
496
3efdcc9c 497
4d3a042d
YO		 498PERL_STATIC_INLINE U32
499S_perl_hash_djb2(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
500 const unsigned char * const end = (const unsigned char *)str + len;
463ddf34 501 U32 hash = *((const U32*)seed) + (U32)len;
4d3a042d
YO		 502 while (str < end) {
503 hash = ((hash << 5) + hash) + *str++;
504 }
505 return hash;
506}
507
508PERL_STATIC_INLINE U32
509S_perl_hash_sdbm(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
510 const unsigned char * const end = (const unsigned char *)str + len;
463ddf34 511 U32 hash = *((const U32*)seed) + (U32)len;
4d3a042d
YO		 512 while (str < end) {
513 hash = (hash << 6) + (hash << 16) - hash + *str++;
514 }
515 return hash;
516}
517
fab3d107
DD		 518/* - ONE_AT_A_TIME_HARD is the 5.17+ recommend ONE_AT_A_TIME algorithm
519 * - ONE_AT_A_TIME_OLD is the unmodified 5.16 and older algorithm
520 * - ONE_AT_A_TIME is a 5.17+ tweak of ONE_AT_A_TIME_OLD to
521 * prevent strings of only \0 but different lengths from colliding
522 *
523 * Security-wise, from best to worst,
524 * ONE_AT_A_TIME_HARD > ONE_AT_A_TIME > ONE_AT_A_TIME_OLD
525 * There is a big drop-off in security between ONE_AT_A_TIME_HARD and
526 * ONE_AT_A_TIME
527 * */
4d3a042d 528
b1300a73 529/* This is the "One-at-a-Time" algorithm by Bob Jenkins
4d3a042d 530 * from requirements by Colin Plumb.
b1300a73
YO		 531 * (http://burtleburtle.net/bob/hash/doobs.html)
532 * With seed/len tweak.
533 * */
4d3a042d
YO		 534PERL_STATIC_INLINE U32
535S_perl_hash_one_at_a_time(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
536 const unsigned char * const end = (const unsigned char *)str + len;
463ddf34 537 U32 hash = *((const U32*)seed) + (U32)len;
4d3a042d
YO		 538 while (str < end) {
539 hash += *str++;
540 hash += (hash << 10);
541 hash ^= (hash >> 6);
542 }
543 hash += (hash << 3);
544 hash ^= (hash >> 11);
545 return (hash + (hash << 15));
546}
547
b1300a73
YO		 548/* Derived from "One-at-a-Time" algorithm by Bob Jenkins */
549PERL_STATIC_INLINE U32
550S_perl_hash_one_at_a_time_hard(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
551 const unsigned char * const end = (const unsigned char *)str + len;
463ddf34 552 U32 hash = *((const U32*)seed) + (U32)len;
b1300a73
YO		 553
554 while (str < end) {
555 hash += (hash << 10);
556 hash ^= (hash >> 6);
557 hash += *str++;
558 }
559
560 hash += (hash << 10);
561 hash ^= (hash >> 6);
562 hash += seed[4];
563
564 hash += (hash << 10);
565 hash ^= (hash >> 6);
566 hash += seed[5];
567
568 hash += (hash << 10);
569 hash ^= (hash >> 6);
570 hash += seed[6];
571
572 hash += (hash << 10);
573 hash ^= (hash >> 6);
574 hash += seed[7];
575
576 hash += (hash << 10);
577 hash ^= (hash >> 6);
578
579 hash += (hash << 3);
580 hash ^= (hash >> 11);
581 return (hash + (hash << 15));
582}
583
6b026047
YO		 584#ifdef HAS_QUAD
585/* For short strings, 16 bytes or shorter, we use an optimised variant
586 * of One At A Time Hard, and for longer strings, we use siphash_1_3.
587 */
588PERL_STATIC_INLINE U32
589S_perl_hash_oaathu_siphash_1_3(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
590 U32 hash = *((const U32*)seed) + (U32)len;
591 switch (len) {
592 case 16:
593 hash += (hash << 10);
594 hash ^= (hash >> 6);
595 hash += str[15];
596 case 15:
597 hash += (hash << 10);
598 hash ^= (hash >> 6);
599 hash += str[14];
600 case 14:
601 hash += (hash << 10);
602 hash ^= (hash >> 6);
603 hash += str[13];
604 case 13:
605 hash += (hash << 10);
606 hash ^= (hash >> 6);
607 hash += str[12];
608 case 12:
609 hash += (hash << 10);
610 hash ^= (hash >> 6);
611 hash += str[11];
612 case 11:
613 hash += (hash << 10);
614 hash ^= (hash >> 6);
615 hash += str[10];
616 case 10:
617 hash += (hash << 10);
618 hash ^= (hash >> 6);
619 hash += str[9];
620 case 9:
621 hash += (hash << 10);
622 hash ^= (hash >> 6);
623 hash += str[8];
624 case 8:
625 hash += (hash << 10);
626 hash ^= (hash >> 6);
627 hash += str[7];
628 case 7:
629 hash += (hash << 10);
630 hash ^= (hash >> 6);
631 hash += str[6];
632 case 6:
633 hash += (hash << 10);
634 hash ^= (hash >> 6);
635 hash += str[5];
636 case 5:
637 hash += (hash << 10);
638 hash ^= (hash >> 6);
639 hash += str[4];
640 case 4:
641 hash += (hash << 10);
642 hash ^= (hash >> 6);
643 hash += str[3];
644 case 3:
645 hash += (hash << 10);
646 hash ^= (hash >> 6);
647 hash += str[2];
648 case 2:
649 hash += (hash << 10);
650 hash ^= (hash >> 6);
651 hash += str[1];
652 case 1:
653 hash += (hash << 10);
654 hash ^= (hash >> 6);
655 hash += str[0];
656 case 0:
657 hash += (hash << 10);
658 hash ^= (hash >> 6);
659 hash += seed[4];
660 hash += (hash << 10);
661 hash ^= (hash >> 6);
662 hash += seed[5];
663 hash += (hash << 10);
664 hash ^= (hash >> 6);
665 hash += seed[6];
666 hash += (hash << 10);
667 hash ^= (hash >> 6);
668 hash += seed[7];
669 hash += (hash << 10);
670 hash ^= (hash >> 6);
671
672 hash += (hash << 3);
673 hash ^= (hash >> 11);
674 return (hash + (hash << 15));
675 }
676 return S_perl_hash_siphash_1_3(seed+8, str, len);
677}
678#endif /* defined(HAS_QUAD) */
679
4d3a042d
YO		 680PERL_STATIC_INLINE U32
681S_perl_hash_old_one_at_a_time(const unsigned char * const seed, const unsigned char *str, const STRLEN len) {
682 const unsigned char * const end = (const unsigned char *)str + len;
463ddf34 683 U32 hash = *((const U32*)seed);
4d3a042d
YO		 684 while (str < end) {
685 hash += *str++;
686 hash += (hash << 10);
687 hash ^= (hash >> 6);
688 }
689 hash += (hash << 3);
690 hash ^= (hash >> 11);
691 return (hash + (hash << 15));
692}
693
7e0dd61b
YO		 694#ifdef PERL_HASH_FUNC_MURMUR_HASH_64A
695/* This code is from Austin Appleby and is in the public domain.
696 Altered by Yves Orton to match Perl's hash interface, and to
697 return a 32 bit hash.
698
699 Note uses unaligned 64 bit loads - will NOT work on machines with
21ac16fe 700 strict alignment requirements.
7e0dd61b
YO		 701
702 Also this code may not be suitable for big-endian machines.
703*/
704
705/* a 64 bit hash where we only use the low 32 bits */
706PERL_STATIC_INLINE U32
707S_perl_hash_murmur_hash_64a (const unsigned char * const seed, const unsigned char *str, const STRLEN len)
708{
702c92eb 709 const U64 m = UINT64_C(0xc6a4a7935bd1e995);
7e0dd61b 710 const int r = 47;
463ddf34 711 U64 h = *((const U64*)seed) ^ len;
702c92eb
JH		 712 const U64 * data = (const U64 *)str;
713 const U64 * end = data + (len/8);
7e0dd61b
YO		 714 const unsigned char * data2;
715
716 while(data != end)
717 {
702c92eb 718 U64 k = *data++;
7e0dd61b
YO		 719
720 k *= m;
721 k ^= k >> r;
722 k *= m;
723
724 h ^= k;
725 h *= m;
726 }
727
728 data2 = (const unsigned char *)data;
729
730 switch(len & 7)
731 {
702c92eb
JH		 732 case 7: h ^= (U64)(data2[6]) << 48; /* fallthrough */
733 case 6: h ^= (U64)(data2[5]) << 40; /* fallthrough */
734 case 5: h ^= (U64)(data2[4]) << 32; /* fallthrough */
735 case 4: h ^= (U64)(data2[3]) << 24; /* fallthrough */
736 case 3: h ^= (U64)(data2[2]) << 16; /* fallthrough */
737 case 2: h ^= (U64)(data2[1]) << 8; /* fallthrough */
738 case 1: h ^= (U64)(data2[0]); /* fallthrough */
7e0dd61b
YO		 739 h *= m;
740 };
741
742 h ^= h >> r;
743 h *= m;
744 h ^= h >> r;
745
746 /* was: return h; */
747 return h & 0xFFFFFFFF;
748}
749
750#endif
751
752#ifdef PERL_HASH_FUNC_MURMUR_HASH_64B
753/* This code is from Austin Appleby and is in the public domain.
754 Altered by Yves Orton to match Perl's hash interface and return
755 a 32 bit value
756
757 Note uses unaligned 32 bit loads - will NOT work on machines with
21ac16fe 758 strict alignment requirements.
7e0dd61b
YO		 759
760 Also this code may not be suitable for big-endian machines.
761*/
762
763/* a 64-bit hash for 32-bit platforms where we only use the low 32 bits */
764PERL_STATIC_INLINE U32
765S_perl_hash_murmur_hash_64b (const unsigned char * const seed, const unsigned char *str, STRLEN len)
766{
767 const U32 m = 0x5bd1e995;
768 const int r = 24;
769
770 U32 h1 = ((U32 *)seed)[0] ^ len;
771 U32 h2 = ((U32 *)seed)[1];
772
773 const U32 * data = (const U32 *)str;
774
775 while(len >= 8)
776 {
777 U32 k1, k2;
778 k1 = *data++;
779 k1 *= m; k1 ^= k1 >> r; k1 *= m;
780 h1 *= m; h1 ^= k1;
781 len -= 4;
782
783 k2 = *data++;
784 k2 *= m; k2 ^= k2 >> r; k2 *= m;
785 h2 *= m; h2 ^= k2;
786 len -= 4;
787 }
788
789 if(len >= 4)
790 {
791 U32 k1 = *data++;
792 k1 *= m; k1 ^= k1 >> r; k1 *= m;
793 h1 *= m; h1 ^= k1;
794 len -= 4;
795 }
796
797 switch(len)
798 {
799 case 3: h2 ^= ((unsigned char*)data)[2] << 16; /* fallthrough */
800 case 2: h2 ^= ((unsigned char*)data)[1] << 8; /* fallthrough */
801 case 1: h2 ^= ((unsigned char*)data)[0]; /* fallthrough */
802 h2 *= m;
803 };
804
805 h1 ^= h2 >> 18; h1 *= m;
806 h2 ^= h1 >> 22; h2 *= m;
807 /*
808 The following code has been removed as it is unused
809 when only the low 32 bits are used. -- Yves
810
811 h1 ^= h2 >> 17; h1 *= m;
812
702c92eb 813 U64 h = h1;
7e0dd61b
YO		 814
815 h = (h << 32) | h2;
816 */
817
818 return h2;
819}
820#endif
821
6b026047 822
4d3a042d
YO		 823/* legacy - only mod_perl should be doing this. */
824#ifdef PERL_HASH_INTERNAL_ACCESS
825#define PERL_HASH_INTERNAL(hash,str,len) PERL_HASH(hash,str,len)
826#endif
827
828#endif /*compile once*/
829
830/*
4d3a042d
YO		 831 * ex: set ts=8 sts=4 sw=4 et:
832 */
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