]>
git.ipfire.org Git - thirdparty/systemd.git/blob - src/journal/lookup3.c
1 /* Slightly modified by Lennart Poettering, to avoid name clashes, and
2 * unexport a few functions. */
7 -------------------------------------------------------------------------------
8 lookup3.c, by Bob Jenkins, May 2006, Public Domain.
10 These are functions for producing 32-bit hashes for hash table lookup.
11 hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final()
12 are externally useful functions. Routines to test the hash are included
13 if SELF_TEST is defined. You can use this free for any purpose. It's in
14 the public domain. It has no warranty.
16 You probably want to use hashlittle(). hashlittle() and hashbig()
17 hash byte arrays. hashlittle() is faster than hashbig() on
18 little-endian machines. Intel and AMD are little-endian machines.
19 On second thought, you probably want hashlittle2(), which is identical to
20 hashlittle() except it returns two 32-bit hashes for the price of one.
21 You could implement hashbig2() if you wanted but I haven't bothered here.
23 If you want to find a hash of, say, exactly 7 integers, do
24 a = i1; b = i2; c = i3;
26 a += i4; b += i5; c += i6;
30 then use c as the hash value. If you have a variable length array of
31 4-byte integers to hash, use hashword(). If you have a byte array (like
32 a character string), use hashlittle(). If you have several byte arrays, or
33 a mix of things, see the comments above hashlittle().
35 Why is this so big? I read 12 bytes at a time into 3 4-byte integers,
36 then mix those integers. This is fast (you can do a lot more thorough
37 mixing with 12*3 instructions on 3 integers than you can with 3 instructions
38 on 1 byte), but shoehorning those bytes into integers efficiently is messy.
39 -------------------------------------------------------------------------------
41 /* #define SELF_TEST 1 */
43 #include <stdint.h> /* defines uint32_t etc */
44 #include <stdio.h> /* defines printf for tests */
45 #include <sys/param.h> /* attempt to define endianness */
46 #include <time.h> /* defines time_t for timings in the test */
48 # include <endian.h> /* attempt to define endianness */
52 _Pragma("GCC diagnostic ignored \"-Wimplicit-fallthrough\"")
56 * My best guess at if you are big-endian or little-endian. This may
59 #if (defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && \
60 __BYTE_ORDER == __LITTLE_ENDIAN) || \
61 (defined(i386) || defined(__i386__) || defined(__i486__) || \
62 defined(__i586__) || defined(__i686__) || defined(vax) || defined(MIPSEL))
63 # define HASH_LITTLE_ENDIAN 1
64 # define HASH_BIG_ENDIAN 0
65 #elif (defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) && \
66 __BYTE_ORDER == __BIG_ENDIAN) || \
67 (defined(sparc) || defined(POWERPC) || defined(mc68000) || defined(sel))
68 # define HASH_LITTLE_ENDIAN 0
69 # define HASH_BIG_ENDIAN 1
71 # define HASH_LITTLE_ENDIAN 0
72 # define HASH_BIG_ENDIAN 0
75 #define hashsize(n) ((uint32_t)1<<(n))
76 #define hashmask(n) (hashsize(n)-1)
77 #define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
80 -------------------------------------------------------------------------------
81 mix -- mix 3 32-bit values reversibly.
83 This is reversible, so any information in (a,b,c) before mix() is
84 still in (a,b,c) after mix().
86 If four pairs of (a,b,c) inputs are run through mix(), or through
87 mix() in reverse, there are at least 32 bits of the output that
88 are sometimes the same for one pair and different for another pair.
90 * pairs that differed by one bit, by two bits, in any combination
91 of top bits of (a,b,c), or in any combination of bottom bits of
93 * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
94 the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
95 is commonly produced by subtraction) look like a single 1-bit
97 * the base values were pseudorandom, all zero but one bit set, or
98 all zero plus a counter that starts at zero.
100 Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that
105 Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing
106 for "differ" defined as + with a one-bit base and a two-bit delta. I
107 used http://burtleburtle.net/bob/hash/avalanche.html to choose
108 the operations, constants, and arrangements of the variables.
110 This does not achieve avalanche. There are input bits of (a,b,c)
111 that fail to affect some output bits of (a,b,c), especially of a. The
112 most thoroughly mixed value is c, but it doesn't really even achieve
115 This allows some parallelism. Read-after-writes are good at doubling
116 the number of bits affected, so the goal of mixing pulls in the opposite
117 direction as the goal of parallelism. I did what I could. Rotates
118 seem to cost as much as shifts on every machine I could lay my hands
119 on, and rotates are much kinder to the top and bottom bits, so I used
121 -------------------------------------------------------------------------------
125 a -= c; a ^= rot(c, 4); c += b; \
126 b -= a; b ^= rot(a, 6); a += c; \
127 c -= b; c ^= rot(b, 8); b += a; \
128 a -= c; a ^= rot(c,16); c += b; \
129 b -= a; b ^= rot(a,19); a += c; \
130 c -= b; c ^= rot(b, 4); b += a; \
134 -------------------------------------------------------------------------------
135 final -- final mixing of 3 32-bit values (a,b,c) into c
137 Pairs of (a,b,c) values differing in only a few bits will usually
138 produce values of c that look totally different. This was tested for
139 * pairs that differed by one bit, by two bits, in any combination
140 of top bits of (a,b,c), or in any combination of bottom bits of
142 * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed
143 the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
144 is commonly produced by subtraction) look like a single 1-bit
146 * the base values were pseudorandom, all zero but one bit set, or
147 all zero plus a counter that starts at zero.
149 These constants passed:
152 and these came close:
156 -------------------------------------------------------------------------------
158 #define final(a,b,c) \
160 c ^= b; c -= rot(b,14); \
161 a ^= c; a -= rot(c,11); \
162 b ^= a; b -= rot(a,25); \
163 c ^= b; c -= rot(b,16); \
164 a ^= c; a -= rot(c,4); \
165 b ^= a; b -= rot(a,14); \
166 c ^= b; c -= rot(b,24); \
170 --------------------------------------------------------------------
171 This works on all machines. To be useful, it requires
172 -- that the key be an array of uint32_t's, and
173 -- that the length be the number of uint32_t's in the key
175 The function hashword() is identical to hashlittle() on little-endian
176 machines, and identical to hashbig() on big-endian machines,
177 except that the length has to be measured in uint32_ts rather than in
178 bytes. hashlittle() is more complicated than hashword() only because
179 hashlittle() has to dance around fitting the key bytes into registers.
180 --------------------------------------------------------------------
182 uint32_t jenkins_hashword(
183 const uint32_t *k
, /* the key, an array of uint32_t values */
184 size_t length
, /* the length of the key, in uint32_ts */
185 uint32_t initval
) /* the previous hash, or an arbitrary value */
189 /* Set up the internal state */
190 a
= b
= c
= 0xdeadbeef + (((uint32_t)length
)<<2) + initval
;
192 /*------------------------------------------------- handle most of the key */
203 /*------------------------------------------- handle the last 3 uint32_t's */
204 switch(length
) /* all the case statements fall through */
210 case 0: /* case 0: nothing left to add */
213 /*------------------------------------------------------ report the result */
218 --------------------------------------------------------------------
219 hashword2() -- same as hashword(), but take two seeds and return two
220 32-bit values. pc and pb must both be nonnull, and *pc and *pb must
221 both be initialized with seeds. If you pass in (*pb)==0, the output
222 (*pc) will be the same as the return value from hashword().
223 --------------------------------------------------------------------
225 void jenkins_hashword2 (
226 const uint32_t *k
, /* the key, an array of uint32_t values */
227 size_t length
, /* the length of the key, in uint32_ts */
228 uint32_t *pc
, /* IN: seed OUT: primary hash value */
229 uint32_t *pb
) /* IN: more seed OUT: secondary hash value */
233 /* Set up the internal state */
234 a
= b
= c
= 0xdeadbeef + ((uint32_t)(length
<<2)) + *pc
;
237 /*------------------------------------------------- handle most of the key */
248 /*------------------------------------------- handle the last 3 uint32_t's */
249 switch(length
) /* all the case statements fall through */
255 case 0: /* case 0: nothing left to add */
258 /*------------------------------------------------------ report the result */
263 -------------------------------------------------------------------------------
264 hashlittle() -- hash a variable-length key into a 32-bit value
265 k : the key (the unaligned variable-length array of bytes)
266 length : the length of the key, counting by bytes
267 initval : can be any 4-byte value
268 Returns a 32-bit value. Every bit of the key affects every bit of
269 the return value. Two keys differing by one or two bits will have
270 totally different hash values.
272 The best hash table sizes are powers of 2. There is no need to do
273 mod a prime (mod is sooo slow!). If you need less than 32 bits,
274 use a bitmask. For example, if you need only 10 bits, do
275 h = (h & hashmask(10));
276 In which case, the hash table should have hashsize(10) elements.
278 If you are hashing n strings (uint8_t **)k, do it like this:
279 for (i=0, h=0; i<n; ++i) h = hashlittle( k[i], len[i], h);
281 By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this
282 code any way you wish, private, educational, or commercial. It's free.
284 Use for hash table lookup, or anything where one collision in 2^^32 is
285 acceptable. Do NOT use for cryptographic purposes.
286 -------------------------------------------------------------------------------
289 uint32_t jenkins_hashlittle( const void *key
, size_t length
, uint32_t initval
)
291 uint32_t a
,b
,c
; /* internal state */
292 union { const void *ptr
; size_t i
; } u
; /* needed for Mac Powerbook G4 */
294 /* Set up the internal state */
295 a
= b
= c
= 0xdeadbeef + ((uint32_t)length
) + initval
;
298 if (HASH_LITTLE_ENDIAN
&& ((u
.i
& 0x3) == 0)) {
299 const uint32_t *k
= (const uint32_t *)key
; /* read 32-bit chunks */
301 /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */
312 /*----------------------------- handle the last (probably partial) block */
314 * "k[2]&0xffffff" actually reads beyond the end of the string, but
315 * then masks off the part it's not allowed to read. Because the
316 * string is aligned, the masked-off tail is in the same word as the
317 * rest of the string. Every machine with memory protection I've seen
318 * does it on word boundaries, so is OK with this. But valgrind will
319 * still catch it and complain. The masking trick does make the hash
320 * noticeably faster for short strings (like English words).
322 #if !VALGRIND && !HAS_FEATURE_ADDRESS_SANITIZER && !HAS_FEATURE_MEMORY_SANITIZER
326 case 12: c
+=k
[2]; b
+=k
[1]; a
+=k
[0]; break;
327 case 11: c
+=k
[2]&0xffffff; b
+=k
[1]; a
+=k
[0]; break;
328 case 10: c
+=k
[2]&0xffff; b
+=k
[1]; a
+=k
[0]; break;
329 case 9 : c
+=k
[2]&0xff; b
+=k
[1]; a
+=k
[0]; break;
330 case 8 : b
+=k
[1]; a
+=k
[0]; break;
331 case 7 : b
+=k
[1]&0xffffff; a
+=k
[0]; break;
332 case 6 : b
+=k
[1]&0xffff; a
+=k
[0]; break;
333 case 5 : b
+=k
[1]&0xff; a
+=k
[0]; break;
334 case 4 : a
+=k
[0]; break;
335 case 3 : a
+=k
[0]&0xffffff; break;
336 case 2 : a
+=k
[0]&0xffff; break;
337 case 1 : a
+=k
[0]&0xff; break;
338 case 0 : return c
; /* zero length strings require no mixing */
341 #else /* make valgrind happy */
343 const uint8_t *k8
= (const uint8_t *) k
;
347 case 12: c
+=k
[2]; b
+=k
[1]; a
+=k
[0]; break;
348 case 11: c
+=((uint32_t)k8
[10])<<16; /* fall through */
349 case 10: c
+=((uint32_t)k8
[9])<<8; /* fall through */
350 case 9 : c
+=k8
[8]; /* fall through */
351 case 8 : b
+=k
[1]; a
+=k
[0]; break;
352 case 7 : b
+=((uint32_t)k8
[6])<<16; /* fall through */
353 case 6 : b
+=((uint32_t)k8
[5])<<8; /* fall through */
354 case 5 : b
+=k8
[4]; /* fall through */
355 case 4 : a
+=k
[0]; break;
356 case 3 : a
+=((uint32_t)k8
[2])<<16; /* fall through */
357 case 2 : a
+=((uint32_t)k8
[1])<<8; /* fall through */
358 case 1 : a
+=k8
[0]; break;
363 #endif /* !valgrind */
365 } else if (HASH_LITTLE_ENDIAN
&& ((u
.i
& 0x1) == 0)) {
366 const uint16_t *k
= (const uint16_t *)key
; /* read 16-bit chunks */
369 /*--------------- all but last block: aligned reads and different mixing */
372 a
+= k
[0] + (((uint32_t)k
[1])<<16);
373 b
+= k
[2] + (((uint32_t)k
[3])<<16);
374 c
+= k
[4] + (((uint32_t)k
[5])<<16);
380 /*----------------------------- handle the last (probably partial) block */
381 k8
= (const uint8_t *)k
;
384 case 12: c
+=k
[4]+(((uint32_t)k
[5])<<16);
385 b
+=k
[2]+(((uint32_t)k
[3])<<16);
386 a
+=k
[0]+(((uint32_t)k
[1])<<16);
388 case 11: c
+=((uint32_t)k8
[10])<<16; /* fall through */
390 b
+=k
[2]+(((uint32_t)k
[3])<<16);
391 a
+=k
[0]+(((uint32_t)k
[1])<<16);
393 case 9 : c
+=k8
[8]; /* fall through */
394 case 8 : b
+=k
[2]+(((uint32_t)k
[3])<<16);
395 a
+=k
[0]+(((uint32_t)k
[1])<<16);
397 case 7 : b
+=((uint32_t)k8
[6])<<16; /* fall through */
399 a
+=k
[0]+(((uint32_t)k
[1])<<16);
401 case 5 : b
+=k8
[4]; /* fall through */
402 case 4 : a
+=k
[0]+(((uint32_t)k
[1])<<16);
404 case 3 : a
+=((uint32_t)k8
[2])<<16; /* fall through */
409 case 0 : return c
; /* zero length requires no mixing */
412 } else { /* need to read the key one byte at a time */
413 const uint8_t *k
= (const uint8_t *)key
;
415 /*--------------- all but the last block: affect some 32 bits of (a,b,c) */
419 a
+= ((uint32_t)k
[1])<<8;
420 a
+= ((uint32_t)k
[2])<<16;
421 a
+= ((uint32_t)k
[3])<<24;
423 b
+= ((uint32_t)k
[5])<<8;
424 b
+= ((uint32_t)k
[6])<<16;
425 b
+= ((uint32_t)k
[7])<<24;
427 c
+= ((uint32_t)k
[9])<<8;
428 c
+= ((uint32_t)k
[10])<<16;
429 c
+= ((uint32_t)k
[11])<<24;
435 /*-------------------------------- last block: affect all 32 bits of (c) */
436 switch(length
) /* all the case statements fall through */
438 case 12: c
+=((uint32_t)k
[11])<<24;
439 case 11: c
+=((uint32_t)k
[10])<<16;
440 case 10: c
+=((uint32_t)k
[9])<<8;
442 case 8 : b
+=((uint32_t)k
[7])<<24;
443 case 7 : b
+=((uint32_t)k
[6])<<16;
444 case 6 : b
+=((uint32_t)k
[5])<<8;
446 case 4 : a
+=((uint32_t)k
[3])<<24;
447 case 3 : a
+=((uint32_t)k
[2])<<16;
448 case 2 : a
+=((uint32_t)k
[1])<<8;
460 * hashlittle2: return 2 32-bit hash values
462 * This is identical to hashlittle(), except it returns two 32-bit hash
463 * values instead of just one. This is good enough for hash table
464 * lookup with 2^^64 buckets, or if you want a second hash if you're not
465 * happy with the first, or if you want a probably-unique 64-bit ID for
466 * the key. *pc is better mixed than *pb, so use *pc first. If you want
467 * a 64-bit value do something like "*pc + (((uint64_t)*pb)<<32)".
469 void jenkins_hashlittle2(
470 const void *key
, /* the key to hash */
471 size_t length
, /* length of the key */
472 uint32_t *pc
, /* IN: primary initval, OUT: primary hash */
473 uint32_t *pb
) /* IN: secondary initval, OUT: secondary hash */
475 uint32_t a
,b
,c
; /* internal state */
476 union { const void *ptr
; size_t i
; } u
; /* needed for Mac Powerbook G4 */
478 /* Set up the internal state */
479 a
= b
= c
= 0xdeadbeef + ((uint32_t)length
) + *pc
;
483 if (HASH_LITTLE_ENDIAN
&& ((u
.i
& 0x3) == 0)) {
484 const uint32_t *k
= (const uint32_t *)key
; /* read 32-bit chunks */
486 /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */
497 /*----------------------------- handle the last (probably partial) block */
499 * "k[2]&0xffffff" actually reads beyond the end of the string, but
500 * then masks off the part it's not allowed to read. Because the
501 * string is aligned, the masked-off tail is in the same word as the
502 * rest of the string. Every machine with memory protection I've seen
503 * does it on word boundaries, so is OK with this. But valgrind will
504 * still catch it and complain. The masking trick does make the hash
505 * noticeably faster for short strings (like English words).
507 #if !VALGRIND && !HAS_FEATURE_ADDRESS_SANITIZER && !HAS_FEATURE_MEMORY_SANITIZER
511 case 12: c
+=k
[2]; b
+=k
[1]; a
+=k
[0]; break;
512 case 11: c
+=k
[2]&0xffffff; b
+=k
[1]; a
+=k
[0]; break;
513 case 10: c
+=k
[2]&0xffff; b
+=k
[1]; a
+=k
[0]; break;
514 case 9 : c
+=k
[2]&0xff; b
+=k
[1]; a
+=k
[0]; break;
515 case 8 : b
+=k
[1]; a
+=k
[0]; break;
516 case 7 : b
+=k
[1]&0xffffff; a
+=k
[0]; break;
517 case 6 : b
+=k
[1]&0xffff; a
+=k
[0]; break;
518 case 5 : b
+=k
[1]&0xff; a
+=k
[0]; break;
519 case 4 : a
+=k
[0]; break;
520 case 3 : a
+=k
[0]&0xffffff; break;
521 case 2 : a
+=k
[0]&0xffff; break;
522 case 1 : a
+=k
[0]&0xff; break;
523 case 0 : *pc
=c
; *pb
=b
; return; /* zero length strings require no mixing */
526 #else /* make valgrind happy */
529 const uint8_t *k8
= (const uint8_t *)k
;
532 case 12: c
+=k
[2]; b
+=k
[1]; a
+=k
[0]; break;
533 case 11: c
+=((uint32_t)k8
[10])<<16; /* fall through */
534 case 10: c
+=((uint32_t)k8
[9])<<8; /* fall through */
535 case 9 : c
+=k8
[8]; /* fall through */
536 case 8 : b
+=k
[1]; a
+=k
[0]; break;
537 case 7 : b
+=((uint32_t)k8
[6])<<16; /* fall through */
538 case 6 : b
+=((uint32_t)k8
[5])<<8; /* fall through */
539 case 5 : b
+=k8
[4]; /* fall through */
540 case 4 : a
+=k
[0]; break;
541 case 3 : a
+=((uint32_t)k8
[2])<<16; /* fall through */
542 case 2 : a
+=((uint32_t)k8
[1])<<8; /* fall through */
543 case 1 : a
+=k8
[0]; break;
544 case 0 : *pc
=c
; *pb
=b
; return; /* zero length strings require no mixing */
548 #endif /* !valgrind */
550 } else if (HASH_LITTLE_ENDIAN
&& ((u
.i
& 0x1) == 0)) {
551 const uint16_t *k
= (const uint16_t *)key
; /* read 16-bit chunks */
554 /*--------------- all but last block: aligned reads and different mixing */
557 a
+= k
[0] + (((uint32_t)k
[1])<<16);
558 b
+= k
[2] + (((uint32_t)k
[3])<<16);
559 c
+= k
[4] + (((uint32_t)k
[5])<<16);
565 /*----------------------------- handle the last (probably partial) block */
566 k8
= (const uint8_t *)k
;
569 case 12: c
+=k
[4]+(((uint32_t)k
[5])<<16);
570 b
+=k
[2]+(((uint32_t)k
[3])<<16);
571 a
+=k
[0]+(((uint32_t)k
[1])<<16);
573 case 11: c
+=((uint32_t)k8
[10])<<16; /* fall through */
575 b
+=k
[2]+(((uint32_t)k
[3])<<16);
576 a
+=k
[0]+(((uint32_t)k
[1])<<16);
578 case 9 : c
+=k8
[8]; /* fall through */
579 case 8 : b
+=k
[2]+(((uint32_t)k
[3])<<16);
580 a
+=k
[0]+(((uint32_t)k
[1])<<16);
582 case 7 : b
+=((uint32_t)k8
[6])<<16; /* fall through */
584 a
+=k
[0]+(((uint32_t)k
[1])<<16);
586 case 5 : b
+=k8
[4]; /* fall through */
587 case 4 : a
+=k
[0]+(((uint32_t)k
[1])<<16);
589 case 3 : a
+=((uint32_t)k8
[2])<<16; /* fall through */
594 case 0 : *pc
=c
; *pb
=b
; return; /* zero length strings require no mixing */
597 } else { /* need to read the key one byte at a time */
598 const uint8_t *k
= (const uint8_t *)key
;
600 /*--------------- all but the last block: affect some 32 bits of (a,b,c) */
604 a
+= ((uint32_t)k
[1])<<8;
605 a
+= ((uint32_t)k
[2])<<16;
606 a
+= ((uint32_t)k
[3])<<24;
608 b
+= ((uint32_t)k
[5])<<8;
609 b
+= ((uint32_t)k
[6])<<16;
610 b
+= ((uint32_t)k
[7])<<24;
612 c
+= ((uint32_t)k
[9])<<8;
613 c
+= ((uint32_t)k
[10])<<16;
614 c
+= ((uint32_t)k
[11])<<24;
620 /*-------------------------------- last block: affect all 32 bits of (c) */
621 switch(length
) /* all the case statements fall through */
623 case 12: c
+=((uint32_t)k
[11])<<24;
624 case 11: c
+=((uint32_t)k
[10])<<16;
625 case 10: c
+=((uint32_t)k
[9])<<8;
627 case 8 : b
+=((uint32_t)k
[7])<<24;
628 case 7 : b
+=((uint32_t)k
[6])<<16;
629 case 6 : b
+=((uint32_t)k
[5])<<8;
631 case 4 : a
+=((uint32_t)k
[3])<<24;
632 case 3 : a
+=((uint32_t)k
[2])<<16;
633 case 2 : a
+=((uint32_t)k
[1])<<8;
636 case 0 : *pc
=c
; *pb
=b
; return; /* zero length strings require no mixing */
646 * This is the same as hashword() on big-endian machines. It is different
647 * from hashlittle() on all machines. hashbig() takes advantage of
648 * big-endian byte ordering.
650 uint32_t jenkins_hashbig( const void *key
, size_t length
, uint32_t initval
)
653 union { const void *ptr
; size_t i
; } u
; /* to cast key to (size_t) happily */
655 /* Set up the internal state */
656 a
= b
= c
= 0xdeadbeef + ((uint32_t)length
) + initval
;
659 if (HASH_BIG_ENDIAN
&& ((u
.i
& 0x3) == 0)) {
660 const uint32_t *k
= (const uint32_t *)key
; /* read 32-bit chunks */
662 /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */
673 /*----------------------------- handle the last (probably partial) block */
675 * "k[2]<<8" actually reads beyond the end of the string, but
676 * then shifts out the part it's not allowed to read. Because the
677 * string is aligned, the illegal read is in the same word as the
678 * rest of the string. Every machine with memory protection I've seen
679 * does it on word boundaries, so is OK with this. But valgrind will
680 * still catch it and complain. The masking trick does make the hash
681 * noticeably faster for short strings (like English words).
683 #if !VALGRIND && !HAS_FEATURE_ADDRESS_SANITIZER && !HAS_FEATURE_MEMORY_SANITIZER
687 case 12: c
+=k
[2]; b
+=k
[1]; a
+=k
[0]; break;
688 case 11: c
+=k
[2]&0xffffff00; b
+=k
[1]; a
+=k
[0]; break;
689 case 10: c
+=k
[2]&0xffff0000; b
+=k
[1]; a
+=k
[0]; break;
690 case 9 : c
+=k
[2]&0xff000000; b
+=k
[1]; a
+=k
[0]; break;
691 case 8 : b
+=k
[1]; a
+=k
[0]; break;
692 case 7 : b
+=k
[1]&0xffffff00; a
+=k
[0]; break;
693 case 6 : b
+=k
[1]&0xffff0000; a
+=k
[0]; break;
694 case 5 : b
+=k
[1]&0xff000000; a
+=k
[0]; break;
695 case 4 : a
+=k
[0]; break;
696 case 3 : a
+=k
[0]&0xffffff00; break;
697 case 2 : a
+=k
[0]&0xffff0000; break;
698 case 1 : a
+=k
[0]&0xff000000; break;
699 case 0 : return c
; /* zero length strings require no mixing */
702 #else /* make valgrind happy */
705 const uint8_t *k8
= (const uint8_t *)k
;
706 switch(length
) /* all the case statements fall through */
708 case 12: c
+=k
[2]; b
+=k
[1]; a
+=k
[0]; break;
709 case 11: c
+=((uint32_t)k8
[10])<<8; /* fall through */
710 case 10: c
+=((uint32_t)k8
[9])<<16; /* fall through */
711 case 9 : c
+=((uint32_t)k8
[8])<<24; /* fall through */
712 case 8 : b
+=k
[1]; a
+=k
[0]; break;
713 case 7 : b
+=((uint32_t)k8
[6])<<8; /* fall through */
714 case 6 : b
+=((uint32_t)k8
[5])<<16; /* fall through */
715 case 5 : b
+=((uint32_t)k8
[4])<<24; /* fall through */
716 case 4 : a
+=k
[0]; break;
717 case 3 : a
+=((uint32_t)k8
[2])<<8; /* fall through */
718 case 2 : a
+=((uint32_t)k8
[1])<<16; /* fall through */
719 case 1 : a
+=((uint32_t)k8
[0])<<24; break;
724 #endif /* !VALGRIND */
726 } else { /* need to read the key one byte at a time */
727 const uint8_t *k
= (const uint8_t *)key
;
729 /*--------------- all but the last block: affect some 32 bits of (a,b,c) */
732 a
+= ((uint32_t)k
[0])<<24;
733 a
+= ((uint32_t)k
[1])<<16;
734 a
+= ((uint32_t)k
[2])<<8;
735 a
+= ((uint32_t)k
[3]);
736 b
+= ((uint32_t)k
[4])<<24;
737 b
+= ((uint32_t)k
[5])<<16;
738 b
+= ((uint32_t)k
[6])<<8;
739 b
+= ((uint32_t)k
[7]);
740 c
+= ((uint32_t)k
[8])<<24;
741 c
+= ((uint32_t)k
[9])<<16;
742 c
+= ((uint32_t)k
[10])<<8;
743 c
+= ((uint32_t)k
[11]);
749 /*-------------------------------- last block: affect all 32 bits of (c) */
750 switch(length
) /* all the case statements fall through */
753 case 11: c
+=((uint32_t)k
[10])<<8;
754 case 10: c
+=((uint32_t)k
[9])<<16;
755 case 9 : c
+=((uint32_t)k
[8])<<24;
757 case 7 : b
+=((uint32_t)k
[6])<<8;
758 case 6 : b
+=((uint32_t)k
[5])<<16;
759 case 5 : b
+=((uint32_t)k
[4])<<24;
761 case 3 : a
+=((uint32_t)k
[2])<<8;
762 case 2 : a
+=((uint32_t)k
[1])<<16;
763 case 1 : a
+=((uint32_t)k
[0])<<24;
775 /* used for timings */
784 for (i
=0; i
<256; ++i
) buf
[i
] = 'x';
787 h
= hashlittle(&buf
[0],1,h
);
790 if (z
-a
> 0) printf("time %d %.8x\n", z
-a
, h
);
793 /* check that every input bit changes every output bit half the time */
800 uint8_t qa
[MAXLEN
+1], qb
[MAXLEN
+2], *a
= &qa
[0], *b
= &qb
[1];
801 uint32_t c
[HASHSTATE
], d
[HASHSTATE
], i
=0, j
=0, k
, l
, m
=0, z
;
802 uint32_t e
[HASHSTATE
],f
[HASHSTATE
],g
[HASHSTATE
],h
[HASHSTATE
];
803 uint32_t x
[HASHSTATE
],y
[HASHSTATE
];
806 printf("No more than %d trials should ever be needed \n",MAXPAIR
/2);
807 for (hlen
=0; hlen
< MAXLEN
; ++hlen
)
810 for (i
=0; i
<hlen
; ++i
) /*----------------------- for each input byte, */
812 for (j
=0; j
<8; ++j
) /*------------------------ for each input bit, */
814 for (m
=1; m
<8; ++m
) /*------------- for several possible initvals, */
816 for (l
=0; l
<HASHSTATE
; ++l
)
817 e
[l
]=f
[l
]=g
[l
]=h
[l
]=x
[l
]=y
[l
]=~((uint32_t)0);
819 /*---- check that every output bit is affected by that input bit */
820 for (k
=0; k
<MAXPAIR
; k
+=2)
823 /* keys have one bit different */
824 for (l
=0; l
<hlen
+1; ++l
) {a
[l
] = b
[l
] = (uint8_t)0;}
825 /* have a and b be two keys differing in only one bit */
828 c
[0] = hashlittle(a
, hlen
, m
);
830 b
[i
] ^= ((k
+1)>>(8-j
));
831 d
[0] = hashlittle(b
, hlen
, m
);
832 /* check every bit is 1, 0, set, and not set at least once */
833 for (l
=0; l
<HASHSTATE
; ++l
)
836 f
[l
] &= ~(c
[l
]^d
[l
]);
841 if (e
[l
]|f
[l
]|g
[l
]|h
[l
]|x
[l
]|y
[l
]) finished
=0;
848 printf("Some bit didn't change: ");
849 printf("%.8x %.8x %.8x %.8x %.8x %.8x ",
850 e
[0],f
[0],g
[0],h
[0],x
[0],y
[0]);
851 printf("i %d j %d m %d len %d\n", i
, j
, m
, hlen
);
853 if (z
==MAXPAIR
) goto done
;
860 printf("Mix success %2d bytes %2d initvals ",i
,m
);
861 printf("required %d trials\n", z
/2);
867 /* Check for reading beyond the end of the buffer and alignment problems */
870 uint8_t buf
[MAXLEN
+20], *b
;
872 uint8_t q
[] = "This is the time for all good men to come to the aid of their country...";
874 uint8_t qq
[] = "xThis is the time for all good men to come to the aid of their country...";
876 uint8_t qqq
[] = "xxThis is the time for all good men to come to the aid of their country...";
878 uint8_t qqqq
[] = "xxxThis is the time for all good men to come to the aid of their country...";
882 printf("Endianness. These lines should all be the same (for values filled in):\n");
883 printf("%.8x %.8x %.8x\n",
884 hashword((const uint32_t *)q
, (sizeof(q
)-1)/4, 13),
885 hashword((const uint32_t *)q
, (sizeof(q
)-5)/4, 13),
886 hashword((const uint32_t *)q
, (sizeof(q
)-9)/4, 13));
888 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n",
889 hashlittle(p
, sizeof(q
)-1, 13), hashlittle(p
, sizeof(q
)-2, 13),
890 hashlittle(p
, sizeof(q
)-3, 13), hashlittle(p
, sizeof(q
)-4, 13),
891 hashlittle(p
, sizeof(q
)-5, 13), hashlittle(p
, sizeof(q
)-6, 13),
892 hashlittle(p
, sizeof(q
)-7, 13), hashlittle(p
, sizeof(q
)-8, 13),
893 hashlittle(p
, sizeof(q
)-9, 13), hashlittle(p
, sizeof(q
)-10, 13),
894 hashlittle(p
, sizeof(q
)-11, 13), hashlittle(p
, sizeof(q
)-12, 13));
896 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n",
897 hashlittle(p
, sizeof(q
)-1, 13), hashlittle(p
, sizeof(q
)-2, 13),
898 hashlittle(p
, sizeof(q
)-3, 13), hashlittle(p
, sizeof(q
)-4, 13),
899 hashlittle(p
, sizeof(q
)-5, 13), hashlittle(p
, sizeof(q
)-6, 13),
900 hashlittle(p
, sizeof(q
)-7, 13), hashlittle(p
, sizeof(q
)-8, 13),
901 hashlittle(p
, sizeof(q
)-9, 13), hashlittle(p
, sizeof(q
)-10, 13),
902 hashlittle(p
, sizeof(q
)-11, 13), hashlittle(p
, sizeof(q
)-12, 13));
904 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n",
905 hashlittle(p
, sizeof(q
)-1, 13), hashlittle(p
, sizeof(q
)-2, 13),
906 hashlittle(p
, sizeof(q
)-3, 13), hashlittle(p
, sizeof(q
)-4, 13),
907 hashlittle(p
, sizeof(q
)-5, 13), hashlittle(p
, sizeof(q
)-6, 13),
908 hashlittle(p
, sizeof(q
)-7, 13), hashlittle(p
, sizeof(q
)-8, 13),
909 hashlittle(p
, sizeof(q
)-9, 13), hashlittle(p
, sizeof(q
)-10, 13),
910 hashlittle(p
, sizeof(q
)-11, 13), hashlittle(p
, sizeof(q
)-12, 13));
912 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n",
913 hashlittle(p
, sizeof(q
)-1, 13), hashlittle(p
, sizeof(q
)-2, 13),
914 hashlittle(p
, sizeof(q
)-3, 13), hashlittle(p
, sizeof(q
)-4, 13),
915 hashlittle(p
, sizeof(q
)-5, 13), hashlittle(p
, sizeof(q
)-6, 13),
916 hashlittle(p
, sizeof(q
)-7, 13), hashlittle(p
, sizeof(q
)-8, 13),
917 hashlittle(p
, sizeof(q
)-9, 13), hashlittle(p
, sizeof(q
)-10, 13),
918 hashlittle(p
, sizeof(q
)-11, 13), hashlittle(p
, sizeof(q
)-12, 13));
921 /* check that hashlittle2 and hashlittle produce the same results */
923 hashlittle2(q
, sizeof(q
), &i
, &j
);
924 if (hashlittle(q
, sizeof(q
), 47) != i
)
925 printf("hashlittle2 and hashlittle mismatch\n");
927 /* check that hashword2 and hashword produce the same results */
930 hashword2(&len
, 1, &i
, &j
);
931 if (hashword(&len
, 1, 47) != i
)
932 printf("hashword2 and hashword mismatch %x %x\n",
933 i
, hashword(&len
, 1, 47));
935 /* check hashlittle doesn't read before or after the ends of the string */
936 for (h
=0, b
=buf
+1; h
<8; ++h
, ++b
)
938 for (i
=0; i
<MAXLEN
; ++i
)
941 for (j
=0; j
<i
; ++j
) *(b
+j
)=0;
943 /* these should all be equal */
944 ref
= hashlittle(b
, len
, (uint32_t)1);
947 x
= hashlittle(b
, len
, (uint32_t)1);
948 y
= hashlittle(b
, len
, (uint32_t)1);
949 if ((ref
!= x
) || (ref
!= y
))
951 printf("alignment error: %.8x %.8x %.8x %d %d\n",ref
,x
,y
,
958 /* check for problems with nulls */
962 uint32_t h
,i
,state
[HASHSTATE
];
965 for (i
=0; i
<HASHSTATE
; ++i
) state
[i
] = 1;
966 printf("These should all be different\n");
967 for (i
=0, h
=0; i
<8; ++i
)
969 h
= hashlittle(buf
, 0, h
);
970 printf("%2ld 0-byte strings, hash is %.8x\n", i
, h
);
977 b
=0, c
=0, hashlittle2("", 0, &c
, &b
);
978 printf("hash is %.8lx %.8lx\n", c
, b
); /* deadbeef deadbeef */
979 b
=0xdeadbeef, c
=0, hashlittle2("", 0, &c
, &b
);
980 printf("hash is %.8lx %.8lx\n", c
, b
); /* bd5b7dde deadbeef */
981 b
=0xdeadbeef, c
=0xdeadbeef, hashlittle2("", 0, &c
, &b
);
982 printf("hash is %.8lx %.8lx\n", c
, b
); /* 9c093ccd bd5b7dde */
983 b
=0, c
=0, hashlittle2("Four score and seven years ago", 30, &c
, &b
);
984 printf("hash is %.8lx %.8lx\n", c
, b
); /* 17770551 ce7226e6 */
985 b
=1, c
=0, hashlittle2("Four score and seven years ago", 30, &c
, &b
);
986 printf("hash is %.8lx %.8lx\n", c
, b
); /* e3607cae bd371de4 */
987 b
=0, c
=1, hashlittle2("Four score and seven years ago", 30, &c
, &b
);
988 printf("hash is %.8lx %.8lx\n", c
, b
); /* cd628161 6cbea4b3 */
989 c
= hashlittle("Four score and seven years ago", 30, 0);
990 printf("hash is %.8lx\n", c
); /* 17770551 */
991 c
= hashlittle("Four score and seven years ago", 30, 1);
992 printf("hash is %.8lx\n", c
); /* cd628161 */
997 driver1(); /* test that the key is hashed: used for timings */
998 driver2(); /* test that whole key is hashed thoroughly */
999 driver3(); /* test that nothing but the key is hashed */
1000 driver4(); /* test hashing multiple buffers (all buffers are null) */
1001 driver5(); /* test the hash against known vectors */
1005 #endif /* SELF_TEST */