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comparison srf2fastq/io_lib-1.12.2/io_lib/jenkins_lookup3.c @ 0:d901c9f41a6a default tip
Migrated tool version 1.0.1 from old tool shed archive to new tool shed repository
author | dawe |
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date | Tue, 07 Jun 2011 17:48:05 -0400 |
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1 /* | |
2 ------------------------------------------------------------------------------- | |
3 lookup3.c, by Bob Jenkins, May 2006, Public Domain. | |
4 | |
5 These are functions for producing 32-bit hashes for hash table lookup. | |
6 hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final() | |
7 are externally useful functions. Routines to test the hash are included | |
8 if SELF_TEST is defined. You can use this free for any purpose. It's in | |
9 the public domain. It has no warranty. | |
10 | |
11 You probably want to use hashlittle(). hashlittle() and hashbig() | |
12 hash byte arrays. hashlittle() is is faster than hashbig() on | |
13 little-endian machines. Intel and AMD are little-endian machines. | |
14 On second thought, you probably want hashlittle2(), which is identical to | |
15 hashlittle() except it returns two 32-bit hashes for the price of one. | |
16 You could implement hashbig2() if you wanted but I haven't bothered here. | |
17 | |
18 If you want to find a hash of, say, exactly 7 integers, do | |
19 a = i1; b = i2; c = i3; | |
20 mix(a,b,c); | |
21 a += i4; b += i5; c += i6; | |
22 mix(a,b,c); | |
23 a += i7; | |
24 final(a,b,c); | |
25 then use c as the hash value. If you have a variable length array of | |
26 4-byte integers to hash, use hashword(). If you have a byte array (like | |
27 a character string), use hashlittle(). If you have several byte arrays, or | |
28 a mix of things, see the comments above hashlittle(). | |
29 | |
30 Why is this so big? I read 12 bytes at a time into 3 4-byte integers, | |
31 then mix those integers. This is fast (you can do a lot more thorough | |
32 mixing with 12*3 instructions on 3 integers than you can with 3 instructions | |
33 on 1 byte), but shoehorning those bytes into integers efficiently is messy. | |
34 ------------------------------------------------------------------------------- | |
35 */ | |
36 /* #define SELF_TEST 1 */ | |
37 | |
38 #include <stdio.h> /* defines printf for tests */ | |
39 #include <time.h> /* defines time_t for timings in the test */ | |
40 #include <inttypes.h> /* defines uint32_t etc */ | |
41 #include <sys/param.h> /* attempt to define endianness */ | |
42 #ifdef linux | |
43 # include <endian.h> /* attempt to define endianness */ | |
44 #endif | |
45 | |
46 #include "io_lib/jenkins_lookup3.h" | |
47 | |
48 /* | |
49 * My best guess at if you are big-endian or little-endian. This may | |
50 * need adjustment. | |
51 */ | |
52 #if (defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && \ | |
53 __BYTE_ORDER == __LITTLE_ENDIAN) || \ | |
54 (defined(i386) || defined(__i386__) || defined(__i486__) || \ | |
55 defined(__i586__) || defined(__i686__) || defined(vax) || defined(MIPSEL)) | |
56 # define HASH_LITTLE_ENDIAN 1 | |
57 # define HASH_BIG_ENDIAN 0 | |
58 #elif (defined(__BYTE_ORDER) && defined(__BIG_ENDIAN) && \ | |
59 __BYTE_ORDER == __BIG_ENDIAN) || \ | |
60 (defined(sparc) || defined(POWERPC) || defined(mc68000) || defined(sel)) | |
61 # define HASH_LITTLE_ENDIAN 0 | |
62 # define HASH_BIG_ENDIAN 1 | |
63 #else | |
64 # define HASH_LITTLE_ENDIAN 0 | |
65 # define HASH_BIG_ENDIAN 0 | |
66 #endif | |
67 | |
68 #define hashsize(n) ((uint32_t)1<<(n)) | |
69 #define hashmask(n) (hashsize(n)-1) | |
70 #define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k)))) | |
71 | |
72 /* | |
73 ------------------------------------------------------------------------------- | |
74 mix -- mix 3 32-bit values reversibly. | |
75 | |
76 This is reversible, so any information in (a,b,c) before mix() is | |
77 still in (a,b,c) after mix(). | |
78 | |
79 If four pairs of (a,b,c) inputs are run through mix(), or through | |
80 mix() in reverse, there are at least 32 bits of the output that | |
81 are sometimes the same for one pair and different for another pair. | |
82 This was tested for: | |
83 * pairs that differed by one bit, by two bits, in any combination | |
84 of top bits of (a,b,c), or in any combination of bottom bits of | |
85 (a,b,c). | |
86 * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed | |
87 the output delta to a Gray code (a^(a>>1)) so a string of 1's (as | |
88 is commonly produced by subtraction) look like a single 1-bit | |
89 difference. | |
90 * the base values were pseudorandom, all zero but one bit set, or | |
91 all zero plus a counter that starts at zero. | |
92 | |
93 Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that | |
94 satisfy this are | |
95 4 6 8 16 19 4 | |
96 9 15 3 18 27 15 | |
97 14 9 3 7 17 3 | |
98 Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing | |
99 for "differ" defined as + with a one-bit base and a two-bit delta. I | |
100 used http://burtleburtle.net/bob/hash/avalanche.html to choose | |
101 the operations, constants, and arrangements of the variables. | |
102 | |
103 This does not achieve avalanche. There are input bits of (a,b,c) | |
104 that fail to affect some output bits of (a,b,c), especially of a. The | |
105 most thoroughly mixed value is c, but it doesn't really even achieve | |
106 avalanche in c. | |
107 | |
108 This allows some parallelism. Read-after-writes are good at doubling | |
109 the number of bits affected, so the goal of mixing pulls in the opposite | |
110 direction as the goal of parallelism. I did what I could. Rotates | |
111 seem to cost as much as shifts on every machine I could lay my hands | |
112 on, and rotates are much kinder to the top and bottom bits, so I used | |
113 rotates. | |
114 ------------------------------------------------------------------------------- | |
115 */ | |
116 #define mix(a,b,c) \ | |
117 { \ | |
118 a -= c; a ^= rot(c, 4); c += b; \ | |
119 b -= a; b ^= rot(a, 6); a += c; \ | |
120 c -= b; c ^= rot(b, 8); b += a; \ | |
121 a -= c; a ^= rot(c,16); c += b; \ | |
122 b -= a; b ^= rot(a,19); a += c; \ | |
123 c -= b; c ^= rot(b, 4); b += a; \ | |
124 } | |
125 | |
126 /* | |
127 ------------------------------------------------------------------------------- | |
128 final -- final mixing of 3 32-bit values (a,b,c) into c | |
129 | |
130 Pairs of (a,b,c) values differing in only a few bits will usually | |
131 produce values of c that look totally different. This was tested for | |
132 * pairs that differed by one bit, by two bits, in any combination | |
133 of top bits of (a,b,c), or in any combination of bottom bits of | |
134 (a,b,c). | |
135 * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed | |
136 the output delta to a Gray code (a^(a>>1)) so a string of 1's (as | |
137 is commonly produced by subtraction) look like a single 1-bit | |
138 difference. | |
139 * the base values were pseudorandom, all zero but one bit set, or | |
140 all zero plus a counter that starts at zero. | |
141 | |
142 These constants passed: | |
143 14 11 25 16 4 14 24 | |
144 12 14 25 16 4 14 24 | |
145 and these came close: | |
146 4 8 15 26 3 22 24 | |
147 10 8 15 26 3 22 24 | |
148 11 8 15 26 3 22 24 | |
149 ------------------------------------------------------------------------------- | |
150 */ | |
151 #define final(a,b,c) \ | |
152 { \ | |
153 c ^= b; c -= rot(b,14); \ | |
154 a ^= c; a -= rot(c,11); \ | |
155 b ^= a; b -= rot(a,25); \ | |
156 c ^= b; c -= rot(b,16); \ | |
157 a ^= c; a -= rot(c,4); \ | |
158 b ^= a; b -= rot(a,14); \ | |
159 c ^= b; c -= rot(b,24); \ | |
160 } | |
161 | |
162 /* | |
163 -------------------------------------------------------------------- | |
164 This works on all machines. To be useful, it requires | |
165 -- that the key be an array of uint32_t's, and | |
166 -- that the length be the number of uint32_t's in the key | |
167 | |
168 The function hashword() is identical to hashlittle() on little-endian | |
169 machines, and identical to hashbig() on big-endian machines, | |
170 except that the length has to be measured in uint32_ts rather than in | |
171 bytes. hashlittle() is more complicated than hashword() only because | |
172 hashlittle() has to dance around fitting the key bytes into registers. | |
173 -------------------------------------------------------------------- | |
174 */ | |
175 static uint32_t hashword( | |
176 const uint32_t *k, /* the key, an array of uint32_t values */ | |
177 size_t length, /* the length of the key, in uint32_ts */ | |
178 uint32_t initval) /* the previous hash, or an arbitrary value */ | |
179 { | |
180 uint32_t a,b,c; | |
181 | |
182 /* Set up the internal state */ | |
183 a = b = c = 0xdeadbeef + (((uint32_t)length)<<2) + initval; | |
184 | |
185 /*------------------------------------------------- handle most of the key */ | |
186 while (length > 3) | |
187 { | |
188 a += k[0]; | |
189 b += k[1]; | |
190 c += k[2]; | |
191 mix(a,b,c); | |
192 length -= 3; | |
193 k += 3; | |
194 } | |
195 | |
196 /*------------------------------------------- handle the last 3 uint32_t's */ | |
197 switch(length) /* all the case statements fall through */ | |
198 { | |
199 case 3 : c+=k[2]; | |
200 case 2 : b+=k[1]; | |
201 case 1 : a+=k[0]; | |
202 final(a,b,c); | |
203 case 0: /* case 0: nothing left to add */ | |
204 break; | |
205 } | |
206 /*------------------------------------------------------ report the result */ | |
207 return c; | |
208 } | |
209 | |
210 | |
211 /* | |
212 -------------------------------------------------------------------- | |
213 hashword2() -- same as hashword(), but take two seeds and return two | |
214 32-bit values. pc and pb must both be nonnull, and *pc and *pb must | |
215 both be initialized with seeds. If you pass in (*pb)==0, the output | |
216 (*pc) will be the same as the return value from hashword(). | |
217 -------------------------------------------------------------------- | |
218 */ | |
219 static void hashword2 ( | |
220 const uint32_t *k, /* the key, an array of uint32_t values */ | |
221 size_t length, /* the length of the key, in uint32_ts */ | |
222 uint32_t *pc, /* IN: seed OUT: primary hash value */ | |
223 uint32_t *pb) /* IN: more seed OUT: secondary hash value */ | |
224 { | |
225 uint32_t a,b,c; | |
226 | |
227 /* Set up the internal state */ | |
228 a = b = c = 0xdeadbeef + ((uint32_t)(length<<2)) + *pc; | |
229 c += *pb; | |
230 | |
231 /*------------------------------------------------- handle most of the key */ | |
232 while (length > 3) | |
233 { | |
234 a += k[0]; | |
235 b += k[1]; | |
236 c += k[2]; | |
237 mix(a,b,c); | |
238 length -= 3; | |
239 k += 3; | |
240 } | |
241 | |
242 /*------------------------------------------- handle the last 3 uint32_t's */ | |
243 switch(length) /* all the case statements fall through */ | |
244 { | |
245 case 3 : c+=k[2]; | |
246 case 2 : b+=k[1]; | |
247 case 1 : a+=k[0]; | |
248 final(a,b,c); | |
249 case 0: /* case 0: nothing left to add */ | |
250 break; | |
251 } | |
252 /*------------------------------------------------------ report the result */ | |
253 *pc=c; *pb=b; | |
254 } | |
255 | |
256 | |
257 /* | |
258 ------------------------------------------------------------------------------- | |
259 hashlittle() -- hash a variable-length key into a 32-bit value | |
260 k : the key (the unaligned variable-length array of bytes) | |
261 length : the length of the key, counting by bytes | |
262 initval : can be any 4-byte value | |
263 Returns a 32-bit value. Every bit of the key affects every bit of | |
264 the return value. Two keys differing by one or two bits will have | |
265 totally different hash values. | |
266 | |
267 The best hash table sizes are powers of 2. There is no need to do | |
268 mod a prime (mod is sooo slow!). If you need less than 32 bits, | |
269 use a bitmask. For example, if you need only 10 bits, do | |
270 h = (h & hashmask(10)); | |
271 In which case, the hash table should have hashsize(10) elements. | |
272 | |
273 If you are hashing n strings (uint8_t **)k, do it like this: | |
274 for (i=0, h=0; i<n; ++i) h = hashlittle( k[i], len[i], h); | |
275 | |
276 By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this | |
277 code any way you wish, private, educational, or commercial. It's free. | |
278 | |
279 Use for hash table lookup, or anything where one collision in 2^^32 is | |
280 acceptable. Do NOT use for cryptographic purposes. | |
281 ------------------------------------------------------------------------------- | |
282 */ | |
283 | |
284 static uint32_t hashlittle( const void *key, size_t length, uint32_t initval) | |
285 { | |
286 uint32_t a,b,c; /* internal state */ | |
287 union { const void *ptr; size_t i; } u; /* needed for Mac Powerbook G4 */ | |
288 | |
289 /* Set up the internal state */ | |
290 a = b = c = 0xdeadbeef + ((uint32_t)length) + initval; | |
291 | |
292 u.ptr = key; | |
293 if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) { | |
294 const uint32_t *k = (const uint32_t *)key; /* read 32-bit chunks */ | |
295 #ifdef VALGRIND | |
296 const uint8_t *k8; | |
297 #endif | |
298 | |
299 /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */ | |
300 while (length > 12) | |
301 { | |
302 a += k[0]; | |
303 b += k[1]; | |
304 c += k[2]; | |
305 mix(a,b,c); | |
306 length -= 12; | |
307 k += 3; | |
308 } | |
309 | |
310 /*----------------------------- handle the last (probably partial) block */ | |
311 /* | |
312 * "k[2]&0xffffff" actually reads beyond the end of the string, but | |
313 * then masks off the part it's not allowed to read. Because the | |
314 * string is aligned, the masked-off tail is in the same word as the | |
315 * rest of the string. Every machine with memory protection I've seen | |
316 * does it on word boundaries, so is OK with this. But VALGRIND will | |
317 * still catch it and complain. The masking trick does make the hash | |
318 * noticably faster for short strings (like English words). | |
319 */ | |
320 #ifndef VALGRIND | |
321 | |
322 switch(length) | |
323 { | |
324 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; | |
325 case 11: c+=k[2]&0xffffff; b+=k[1]; a+=k[0]; break; | |
326 case 10: c+=k[2]&0xffff; b+=k[1]; a+=k[0]; break; | |
327 case 9 : c+=k[2]&0xff; b+=k[1]; a+=k[0]; break; | |
328 case 8 : b+=k[1]; a+=k[0]; break; | |
329 case 7 : b+=k[1]&0xffffff; a+=k[0]; break; | |
330 case 6 : b+=k[1]&0xffff; a+=k[0]; break; | |
331 case 5 : b+=k[1]&0xff; a+=k[0]; break; | |
332 case 4 : a+=k[0]; break; | |
333 case 3 : a+=k[0]&0xffffff; break; | |
334 case 2 : a+=k[0]&0xffff; break; | |
335 case 1 : a+=k[0]&0xff; break; | |
336 case 0 : return c; /* zero length strings require no mixing */ | |
337 } | |
338 | |
339 #else /* make valgrind happy */ | |
340 | |
341 k8 = (const uint8_t *)k; | |
342 switch(length) | |
343 { | |
344 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; | |
345 case 11: c+=((uint32_t)k8[10])<<16; /* fall through */ | |
346 case 10: c+=((uint32_t)k8[9])<<8; /* fall through */ | |
347 case 9 : c+=k8[8]; /* fall through */ | |
348 case 8 : b+=k[1]; a+=k[0]; break; | |
349 case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */ | |
350 case 6 : b+=((uint32_t)k8[5])<<8; /* fall through */ | |
351 case 5 : b+=k8[4]; /* fall through */ | |
352 case 4 : a+=k[0]; break; | |
353 case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */ | |
354 case 2 : a+=((uint32_t)k8[1])<<8; /* fall through */ | |
355 case 1 : a+=k8[0]; break; | |
356 case 0 : return c; | |
357 } | |
358 | |
359 #endif /* !valgrind */ | |
360 | |
361 } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) { | |
362 const uint16_t *k = (const uint16_t *)key; /* read 16-bit chunks */ | |
363 const uint8_t *k8; | |
364 | |
365 /*--------------- all but last block: aligned reads and different mixing */ | |
366 while (length > 12) | |
367 { | |
368 a += k[0] + (((uint32_t)k[1])<<16); | |
369 b += k[2] + (((uint32_t)k[3])<<16); | |
370 c += k[4] + (((uint32_t)k[5])<<16); | |
371 mix(a,b,c); | |
372 length -= 12; | |
373 k += 6; | |
374 } | |
375 | |
376 /*----------------------------- handle the last (probably partial) block */ | |
377 k8 = (const uint8_t *)k; | |
378 switch(length) | |
379 { | |
380 case 12: c+=k[4]+(((uint32_t)k[5])<<16); | |
381 b+=k[2]+(((uint32_t)k[3])<<16); | |
382 a+=k[0]+(((uint32_t)k[1])<<16); | |
383 break; | |
384 case 11: c+=((uint32_t)k8[10])<<16; /* fall through */ | |
385 case 10: c+=k[4]; | |
386 b+=k[2]+(((uint32_t)k[3])<<16); | |
387 a+=k[0]+(((uint32_t)k[1])<<16); | |
388 break; | |
389 case 9 : c+=k8[8]; /* fall through */ | |
390 case 8 : b+=k[2]+(((uint32_t)k[3])<<16); | |
391 a+=k[0]+(((uint32_t)k[1])<<16); | |
392 break; | |
393 case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */ | |
394 case 6 : b+=k[2]; | |
395 a+=k[0]+(((uint32_t)k[1])<<16); | |
396 break; | |
397 case 5 : b+=k8[4]; /* fall through */ | |
398 case 4 : a+=k[0]+(((uint32_t)k[1])<<16); | |
399 break; | |
400 case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */ | |
401 case 2 : a+=k[0]; | |
402 break; | |
403 case 1 : a+=k8[0]; | |
404 break; | |
405 case 0 : return c; /* zero length requires no mixing */ | |
406 } | |
407 | |
408 } else { /* need to read the key one byte at a time */ | |
409 const uint8_t *k = (const uint8_t *)key; | |
410 | |
411 /*--------------- all but the last block: affect some 32 bits of (a,b,c) */ | |
412 while (length > 12) | |
413 { | |
414 a += k[0]; | |
415 a += ((uint32_t)k[1])<<8; | |
416 a += ((uint32_t)k[2])<<16; | |
417 a += ((uint32_t)k[3])<<24; | |
418 b += k[4]; | |
419 b += ((uint32_t)k[5])<<8; | |
420 b += ((uint32_t)k[6])<<16; | |
421 b += ((uint32_t)k[7])<<24; | |
422 c += k[8]; | |
423 c += ((uint32_t)k[9])<<8; | |
424 c += ((uint32_t)k[10])<<16; | |
425 c += ((uint32_t)k[11])<<24; | |
426 mix(a,b,c); | |
427 length -= 12; | |
428 k += 12; | |
429 } | |
430 | |
431 /*-------------------------------- last block: affect all 32 bits of (c) */ | |
432 switch(length) /* all the case statements fall through */ | |
433 { | |
434 case 12: c+=((uint32_t)k[11])<<24; | |
435 case 11: c+=((uint32_t)k[10])<<16; | |
436 case 10: c+=((uint32_t)k[9])<<8; | |
437 case 9 : c+=k[8]; | |
438 case 8 : b+=((uint32_t)k[7])<<24; | |
439 case 7 : b+=((uint32_t)k[6])<<16; | |
440 case 6 : b+=((uint32_t)k[5])<<8; | |
441 case 5 : b+=k[4]; | |
442 case 4 : a+=((uint32_t)k[3])<<24; | |
443 case 3 : a+=((uint32_t)k[2])<<16; | |
444 case 2 : a+=((uint32_t)k[1])<<8; | |
445 case 1 : a+=k[0]; | |
446 break; | |
447 case 0 : return c; | |
448 } | |
449 } | |
450 | |
451 final(a,b,c); | |
452 return c; | |
453 } | |
454 | |
455 | |
456 /* | |
457 * hashlittle2: return 2 32-bit hash values | |
458 * | |
459 * This is identical to hashlittle(), except it returns two 32-bit hash | |
460 * values instead of just one. This is good enough for hash table | |
461 * lookup with 2^^64 buckets, or if you want a second hash if you're not | |
462 * happy with the first, or if you want a probably-unique 64-bit ID for | |
463 * the key. *pc is better mixed than *pb, so use *pc first. If you want | |
464 * a 64-bit value do something like "*pc + (((uint64_t)*pb)<<32)". | |
465 */ | |
466 void HashJenkins3( | |
467 const void *key, /* the key to hash */ | |
468 size_t length, /* length of the key */ | |
469 uint32_t *pc, /* IN: primary initval, OUT: primary hash */ | |
470 uint32_t *pb) /* IN: secondary initval, OUT: secondary hash */ | |
471 { | |
472 uint32_t a,b,c; /* internal state */ | |
473 union { const void *ptr; size_t i; } u; /* needed for Mac Powerbook G4 */ | |
474 | |
475 /* Set up the internal state */ | |
476 a = b = c = 0xdeadbeef + ((uint32_t)length) + *pc; | |
477 c += *pb; | |
478 | |
479 u.ptr = key; | |
480 if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) { | |
481 const uint32_t *k = (const uint32_t *)key; /* read 32-bit chunks */ | |
482 #ifdef VALGRIND | |
483 const uint8_t *k8; | |
484 #endif | |
485 | |
486 /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */ | |
487 while (length > 12) | |
488 { | |
489 a += k[0]; | |
490 b += k[1]; | |
491 c += k[2]; | |
492 mix(a,b,c); | |
493 length -= 12; | |
494 k += 3; | |
495 } | |
496 | |
497 /*----------------------------- handle the last (probably partial) block */ | |
498 /* | |
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 * noticably faster for short strings (like English words). | |
506 */ | |
507 #ifndef VALGRIND | |
508 | |
509 switch(length) | |
510 { | |
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 */ | |
524 } | |
525 | |
526 #else /* make valgrind happy */ | |
527 | |
528 k8 = (const uint8_t *)k; | |
529 switch(length) | |
530 { | |
531 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; | |
532 case 11: c+=((uint32_t)k8[10])<<16; /* fall through */ | |
533 case 10: c+=((uint32_t)k8[9])<<8; /* fall through */ | |
534 case 9 : c+=k8[8]; /* fall through */ | |
535 case 8 : b+=k[1]; a+=k[0]; break; | |
536 case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */ | |
537 case 6 : b+=((uint32_t)k8[5])<<8; /* fall through */ | |
538 case 5 : b+=k8[4]; /* fall through */ | |
539 case 4 : a+=k[0]; break; | |
540 case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */ | |
541 case 2 : a+=((uint32_t)k8[1])<<8; /* fall through */ | |
542 case 1 : a+=k8[0]; break; | |
543 case 0 : *pc=c; *pb=b; return; /* zero length strings require no mixing */ | |
544 } | |
545 | |
546 #endif /* !valgrind */ | |
547 | |
548 } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) { | |
549 const uint16_t *k = (const uint16_t *)key; /* read 16-bit chunks */ | |
550 const uint8_t *k8; | |
551 | |
552 /*--------------- all but last block: aligned reads and different mixing */ | |
553 while (length > 12) | |
554 { | |
555 a += k[0] + (((uint32_t)k[1])<<16); | |
556 b += k[2] + (((uint32_t)k[3])<<16); | |
557 c += k[4] + (((uint32_t)k[5])<<16); | |
558 mix(a,b,c); | |
559 length -= 12; | |
560 k += 6; | |
561 } | |
562 | |
563 /*----------------------------- handle the last (probably partial) block */ | |
564 k8 = (const uint8_t *)k; | |
565 switch(length) | |
566 { | |
567 case 12: c+=k[4]+(((uint32_t)k[5])<<16); | |
568 b+=k[2]+(((uint32_t)k[3])<<16); | |
569 a+=k[0]+(((uint32_t)k[1])<<16); | |
570 break; | |
571 case 11: c+=((uint32_t)k8[10])<<16; /* fall through */ | |
572 case 10: c+=k[4]; | |
573 b+=k[2]+(((uint32_t)k[3])<<16); | |
574 a+=k[0]+(((uint32_t)k[1])<<16); | |
575 break; | |
576 case 9 : c+=k8[8]; /* fall through */ | |
577 case 8 : b+=k[2]+(((uint32_t)k[3])<<16); | |
578 a+=k[0]+(((uint32_t)k[1])<<16); | |
579 break; | |
580 case 7 : b+=((uint32_t)k8[6])<<16; /* fall through */ | |
581 case 6 : b+=k[2]; | |
582 a+=k[0]+(((uint32_t)k[1])<<16); | |
583 break; | |
584 case 5 : b+=k8[4]; /* fall through */ | |
585 case 4 : a+=k[0]+(((uint32_t)k[1])<<16); | |
586 break; | |
587 case 3 : a+=((uint32_t)k8[2])<<16; /* fall through */ | |
588 case 2 : a+=k[0]; | |
589 break; | |
590 case 1 : a+=k8[0]; | |
591 break; | |
592 case 0 : *pc=c; *pb=b; return; /* zero length strings require no mixing */ | |
593 } | |
594 | |
595 } else { /* need to read the key one byte at a time */ | |
596 const uint8_t *k = (const uint8_t *)key; | |
597 | |
598 /*--------------- all but the last block: affect some 32 bits of (a,b,c) */ | |
599 while (length > 12) | |
600 { | |
601 a += k[0]; | |
602 a += ((uint32_t)k[1])<<8; | |
603 a += ((uint32_t)k[2])<<16; | |
604 a += ((uint32_t)k[3])<<24; | |
605 b += k[4]; | |
606 b += ((uint32_t)k[5])<<8; | |
607 b += ((uint32_t)k[6])<<16; | |
608 b += ((uint32_t)k[7])<<24; | |
609 c += k[8]; | |
610 c += ((uint32_t)k[9])<<8; | |
611 c += ((uint32_t)k[10])<<16; | |
612 c += ((uint32_t)k[11])<<24; | |
613 mix(a,b,c); | |
614 length -= 12; | |
615 k += 12; | |
616 } | |
617 | |
618 /*-------------------------------- last block: affect all 32 bits of (c) */ | |
619 switch(length) /* all the case statements fall through */ | |
620 { | |
621 case 12: c+=((uint32_t)k[11])<<24; | |
622 case 11: c+=((uint32_t)k[10])<<16; | |
623 case 10: c+=((uint32_t)k[9])<<8; | |
624 case 9 : c+=k[8]; | |
625 case 8 : b+=((uint32_t)k[7])<<24; | |
626 case 7 : b+=((uint32_t)k[6])<<16; | |
627 case 6 : b+=((uint32_t)k[5])<<8; | |
628 case 5 : b+=k[4]; | |
629 case 4 : a+=((uint32_t)k[3])<<24; | |
630 case 3 : a+=((uint32_t)k[2])<<16; | |
631 case 2 : a+=((uint32_t)k[1])<<8; | |
632 case 1 : a+=k[0]; | |
633 break; | |
634 case 0 : *pc=c; *pb=b; return; /* zero length strings require no mixing */ | |
635 } | |
636 } | |
637 | |
638 final(a,b,c); | |
639 *pc=c; *pb=b; | |
640 } | |
641 | |
642 | |
643 | |
644 /* | |
645 * hashbig(): | |
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. | |
649 */ | |
650 static uint32_t hashbig( const void *key, size_t length, uint32_t initval) | |
651 { | |
652 uint32_t a,b,c; | |
653 union { const void *ptr; size_t i; } u; /* to cast key to (size_t) happily */ | |
654 | |
655 /* Set up the internal state */ | |
656 a = b = c = 0xdeadbeef + ((uint32_t)length) + initval; | |
657 | |
658 u.ptr = key; | |
659 if (HASH_BIG_ENDIAN && ((u.i & 0x3) == 0)) { | |
660 const uint32_t *k = (const uint32_t *)key; /* read 32-bit chunks */ | |
661 #ifdef VALGRIND | |
662 const uint8_t *k8; | |
663 #endif | |
664 | |
665 /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */ | |
666 while (length > 12) | |
667 { | |
668 a += k[0]; | |
669 b += k[1]; | |
670 c += k[2]; | |
671 mix(a,b,c); | |
672 length -= 12; | |
673 k += 3; | |
674 } | |
675 | |
676 /*----------------------------- handle the last (probably partial) block */ | |
677 /* | |
678 * "k[2]<<8" actually reads beyond the end of the string, but | |
679 * then shifts out the part it's not allowed to read. Because the | |
680 * string is aligned, the illegal read is in the same word as the | |
681 * rest of the string. Every machine with memory protection I've seen | |
682 * does it on word boundaries, so is OK with this. But VALGRIND will | |
683 * still catch it and complain. The masking trick does make the hash | |
684 * noticably faster for short strings (like English words). | |
685 */ | |
686 #ifndef VALGRIND | |
687 | |
688 switch(length) | |
689 { | |
690 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; | |
691 case 11: c+=k[2]&0xffffff00; b+=k[1]; a+=k[0]; break; | |
692 case 10: c+=k[2]&0xffff0000; b+=k[1]; a+=k[0]; break; | |
693 case 9 : c+=k[2]&0xff000000; b+=k[1]; a+=k[0]; break; | |
694 case 8 : b+=k[1]; a+=k[0]; break; | |
695 case 7 : b+=k[1]&0xffffff00; a+=k[0]; break; | |
696 case 6 : b+=k[1]&0xffff0000; a+=k[0]; break; | |
697 case 5 : b+=k[1]&0xff000000; a+=k[0]; break; | |
698 case 4 : a+=k[0]; break; | |
699 case 3 : a+=k[0]&0xffffff00; break; | |
700 case 2 : a+=k[0]&0xffff0000; break; | |
701 case 1 : a+=k[0]&0xff000000; break; | |
702 case 0 : return c; /* zero length strings require no mixing */ | |
703 } | |
704 | |
705 #else /* make valgrind happy */ | |
706 | |
707 k8 = (const uint8_t *)k; | |
708 switch(length) /* all the case statements fall through */ | |
709 { | |
710 case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; | |
711 case 11: c+=((uint32_t)k8[10])<<8; /* fall through */ | |
712 case 10: c+=((uint32_t)k8[9])<<16; /* fall through */ | |
713 case 9 : c+=((uint32_t)k8[8])<<24; /* fall through */ | |
714 case 8 : b+=k[1]; a+=k[0]; break; | |
715 case 7 : b+=((uint32_t)k8[6])<<8; /* fall through */ | |
716 case 6 : b+=((uint32_t)k8[5])<<16; /* fall through */ | |
717 case 5 : b+=((uint32_t)k8[4])<<24; /* fall through */ | |
718 case 4 : a+=k[0]; break; | |
719 case 3 : a+=((uint32_t)k8[2])<<8; /* fall through */ | |
720 case 2 : a+=((uint32_t)k8[1])<<16; /* fall through */ | |
721 case 1 : a+=((uint32_t)k8[0])<<24; break; | |
722 case 0 : return c; | |
723 } | |
724 | |
725 #endif /* !VALGRIND */ | |
726 | |
727 } else { /* need to read the key one byte at a time */ | |
728 const uint8_t *k = (const uint8_t *)key; | |
729 | |
730 /*--------------- all but the last block: affect some 32 bits of (a,b,c) */ | |
731 while (length > 12) | |
732 { | |
733 a += ((uint32_t)k[0])<<24; | |
734 a += ((uint32_t)k[1])<<16; | |
735 a += ((uint32_t)k[2])<<8; | |
736 a += ((uint32_t)k[3]); | |
737 b += ((uint32_t)k[4])<<24; | |
738 b += ((uint32_t)k[5])<<16; | |
739 b += ((uint32_t)k[6])<<8; | |
740 b += ((uint32_t)k[7]); | |
741 c += ((uint32_t)k[8])<<24; | |
742 c += ((uint32_t)k[9])<<16; | |
743 c += ((uint32_t)k[10])<<8; | |
744 c += ((uint32_t)k[11]); | |
745 mix(a,b,c); | |
746 length -= 12; | |
747 k += 12; | |
748 } | |
749 | |
750 /*-------------------------------- last block: affect all 32 bits of (c) */ | |
751 switch(length) /* all the case statements fall through */ | |
752 { | |
753 case 12: c+=k[11]; | |
754 case 11: c+=((uint32_t)k[10])<<8; | |
755 case 10: c+=((uint32_t)k[9])<<16; | |
756 case 9 : c+=((uint32_t)k[8])<<24; | |
757 case 8 : b+=k[7]; | |
758 case 7 : b+=((uint32_t)k[6])<<8; | |
759 case 6 : b+=((uint32_t)k[5])<<16; | |
760 case 5 : b+=((uint32_t)k[4])<<24; | |
761 case 4 : a+=k[3]; | |
762 case 3 : a+=((uint32_t)k[2])<<8; | |
763 case 2 : a+=((uint32_t)k[1])<<16; | |
764 case 1 : a+=((uint32_t)k[0])<<24; | |
765 break; | |
766 case 0 : return c; | |
767 } | |
768 } | |
769 | |
770 final(a,b,c); | |
771 return c; | |
772 } | |
773 | |
774 | |
775 #ifdef SELF_TEST | |
776 | |
777 /* used for timings */ | |
778 void driver1() | |
779 { | |
780 uint8_t buf[256]; | |
781 uint32_t i; | |
782 uint32_t h=0; | |
783 time_t a,z; | |
784 | |
785 time(&a); | |
786 for (i=0; i<256; ++i) buf[i] = 'x'; | |
787 for (i=0; i<1; ++i) | |
788 { | |
789 h = hashlittle(&buf[0],1,h); | |
790 } | |
791 time(&z); | |
792 if (z-a > 0) printf("time %d %.8x\n", z-a, h); | |
793 } | |
794 | |
795 /* check that every input bit changes every output bit half the time */ | |
796 #define HASHSTATE 1 | |
797 #define HASHLEN 1 | |
798 #define MAXPAIR 60 | |
799 #define MAXLEN 70 | |
800 void driver2() | |
801 { | |
802 uint8_t qa[MAXLEN+1], qb[MAXLEN+2], *a = &qa[0], *b = &qb[1]; | |
803 uint32_t c[HASHSTATE], d[HASHSTATE], i=0, j=0, k, l, m=0, z; | |
804 uint32_t e[HASHSTATE],f[HASHSTATE],g[HASHSTATE],h[HASHSTATE]; | |
805 uint32_t x[HASHSTATE],y[HASHSTATE]; | |
806 uint32_t hlen; | |
807 | |
808 printf("No more than %d trials should ever be needed \n",MAXPAIR/2); | |
809 for (hlen=0; hlen < MAXLEN; ++hlen) | |
810 { | |
811 z=0; | |
812 for (i=0; i<hlen; ++i) /*----------------------- for each input byte, */ | |
813 { | |
814 for (j=0; j<8; ++j) /*------------------------ for each input bit, */ | |
815 { | |
816 for (m=1; m<8; ++m) /*------------ for serveral possible initvals, */ | |
817 { | |
818 for (l=0; l<HASHSTATE; ++l) | |
819 e[l]=f[l]=g[l]=h[l]=x[l]=y[l]=~((uint32_t)0); | |
820 | |
821 /*---- check that every output bit is affected by that input bit */ | |
822 for (k=0; k<MAXPAIR; k+=2) | |
823 { | |
824 uint32_t finished=1; | |
825 /* keys have one bit different */ | |
826 for (l=0; l<hlen+1; ++l) {a[l] = b[l] = (uint8_t)0;} | |
827 /* have a and b be two keys differing in only one bit */ | |
828 a[i] ^= (k<<j); | |
829 a[i] ^= (k>>(8-j)); | |
830 c[0] = hashlittle(a, hlen, m); | |
831 b[i] ^= ((k+1)<<j); | |
832 b[i] ^= ((k+1)>>(8-j)); | |
833 d[0] = hashlittle(b, hlen, m); | |
834 /* check every bit is 1, 0, set, and not set at least once */ | |
835 for (l=0; l<HASHSTATE; ++l) | |
836 { | |
837 e[l] &= (c[l]^d[l]); | |
838 f[l] &= ~(c[l]^d[l]); | |
839 g[l] &= c[l]; | |
840 h[l] &= ~c[l]; | |
841 x[l] &= d[l]; | |
842 y[l] &= ~d[l]; | |
843 if (e[l]|f[l]|g[l]|h[l]|x[l]|y[l]) finished=0; | |
844 } | |
845 if (finished) break; | |
846 } | |
847 if (k>z) z=k; | |
848 if (k==MAXPAIR) | |
849 { | |
850 printf("Some bit didn't change: "); | |
851 printf("%.8x %.8x %.8x %.8x %.8x %.8x ", | |
852 e[0],f[0],g[0],h[0],x[0],y[0]); | |
853 printf("i %d j %d m %d len %d\n", i, j, m, hlen); | |
854 } | |
855 if (z==MAXPAIR) goto done; | |
856 } | |
857 } | |
858 } | |
859 done: | |
860 if (z < MAXPAIR) | |
861 { | |
862 printf("Mix success %2d bytes %2d initvals ",i,m); | |
863 printf("required %d trials\n", z/2); | |
864 } | |
865 } | |
866 printf("\n"); | |
867 } | |
868 | |
869 /* Check for reading beyond the end of the buffer and alignment problems */ | |
870 void driver3() | |
871 { | |
872 uint8_t buf[MAXLEN+20], *b; | |
873 uint32_t len; | |
874 uint8_t q[] = "This is the time for all good men to come to the aid of their country..."; | |
875 uint32_t h; | |
876 uint8_t qq[] = "xThis is the time for all good men to come to the aid of their country..."; | |
877 uint32_t i; | |
878 uint8_t qqq[] = "xxThis is the time for all good men to come to the aid of their country..."; | |
879 uint32_t j; | |
880 uint8_t qqqq[] = "xxxThis is the time for all good men to come to the aid of their country..."; | |
881 uint32_t ref,x,y; | |
882 uint8_t *p; | |
883 | |
884 printf("Endianness. These lines should all be the same (for values filled in):\n"); | |
885 printf("%.8x %.8x %.8x\n", | |
886 hashword((const uint32_t *)q, (sizeof(q)-1)/4, 13), | |
887 hashword((const uint32_t *)q, (sizeof(q)-5)/4, 13), | |
888 hashword((const uint32_t *)q, (sizeof(q)-9)/4, 13)); | |
889 p = q; | |
890 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", | |
891 hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), | |
892 hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), | |
893 hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), | |
894 hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), | |
895 hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), | |
896 hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); | |
897 p = &qq[1]; | |
898 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", | |
899 hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), | |
900 hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), | |
901 hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), | |
902 hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), | |
903 hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), | |
904 hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); | |
905 p = &qqq[2]; | |
906 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", | |
907 hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), | |
908 hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), | |
909 hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), | |
910 hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), | |
911 hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), | |
912 hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); | |
913 p = &qqqq[3]; | |
914 printf("%.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x %.8x\n", | |
915 hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), | |
916 hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), | |
917 hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), | |
918 hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), | |
919 hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), | |
920 hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); | |
921 printf("\n"); | |
922 | |
923 /* check that hashlittle2 and hashlittle produce the same results */ | |
924 i=47; j=0; | |
925 hashlittle2(q, sizeof(q), &i, &j); | |
926 if (hashlittle(q, sizeof(q), 47) != i) | |
927 printf("hashlittle2 and hashlittle mismatch\n"); | |
928 | |
929 /* check that hashword2 and hashword produce the same results */ | |
930 len = 0xdeadbeef; | |
931 i=47, j=0; | |
932 hashword2(&len, 1, &i, &j); | |
933 if (hashword(&len, 1, 47) != i) | |
934 printf("hashword2 and hashword mismatch %x %x\n", | |
935 i, hashword(&len, 1, 47)); | |
936 | |
937 /* check hashlittle doesn't read before or after the ends of the string */ | |
938 for (h=0, b=buf+1; h<8; ++h, ++b) | |
939 { | |
940 for (i=0; i<MAXLEN; ++i) | |
941 { | |
942 len = i; | |
943 for (j=0; j<i; ++j) *(b+j)=0; | |
944 | |
945 /* these should all be equal */ | |
946 ref = hashlittle(b, len, (uint32_t)1); | |
947 *(b+i)=(uint8_t)~0; | |
948 *(b-1)=(uint8_t)~0; | |
949 x = hashlittle(b, len, (uint32_t)1); | |
950 y = hashlittle(b, len, (uint32_t)1); | |
951 if ((ref != x) || (ref != y)) | |
952 { | |
953 printf("alignment error: %.8x %.8x %.8x %d %d\n",ref,x,y, | |
954 h, i); | |
955 } | |
956 } | |
957 } | |
958 } | |
959 | |
960 /* check for problems with nulls */ | |
961 void driver4() | |
962 { | |
963 uint8_t buf[1]; | |
964 uint32_t h,i,state[HASHSTATE]; | |
965 | |
966 | |
967 buf[0] = ~0; | |
968 for (i=0; i<HASHSTATE; ++i) state[i] = 1; | |
969 printf("These should all be different\n"); | |
970 for (i=0, h=0; i<8; ++i) | |
971 { | |
972 h = hashlittle(buf, 0, h); | |
973 printf("%2ld 0-byte strings, hash is %.8x\n", i, h); | |
974 } | |
975 } | |
976 | |
977 | |
978 int main() | |
979 { | |
980 driver1(); /* test that the key is hashed: used for timings */ | |
981 driver2(); /* test that whole key is hashed thoroughly */ | |
982 driver3(); /* test that nothing but the key is hashed */ | |
983 driver4(); /* test hashing multiple buffers (all buffers are null) */ | |
984 return 1; | |
985 } | |
986 | |
987 #endif /* SELF_TEST */ |