1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3 * Copyright (c) 2012 Lawrence Livermore National Laboratory
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation;
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Author: Peter D. Barnes, Jr. <pdbarnes@llnl.gov>
19 *
20 * This copyright notice applies strictly to the wrapper material.
21 *
22 * The murmur3 source code itself is in the public domain. The murmur3 source
23 * code sections are marked by
24 * // Begin <murmur3-file> ---->
25 * and
26 * // End <murmur3-file> ---->
27 * comments.
28 *
29 * Changes from the murmur3 distribution are marked with `//PDB'
30 * In addition comment blocks have been converted to Doxygen format.
31 * Function arguments for buffer length which were originally
32 * "int len" or "int i" have been changed to "std::size_t".
33 * In the _x86 versions the main loop used negative indexes, as shown.
34 * Other conversions to std::size_t are marked.
35 */
36
37 #include "log.h"
38 #include "hash-murmur3.h"
39
40 #include <iomanip>
41
42 /**
43 * \file
44 * \ingroup hash
45 * \brief ns3::Hash::Function::Murmur3 implementation.
46 */
47
48 namespace ns3 {
49
50 NS_LOG_COMPONENT_DEFINE ("Hash-Murmur3");
51
52 namespace Hash {
53
54 namespace Function {
55
56 /** Murmur3 hash implementation details. */
57 namespace Murmur3Implementation {
58
59 /**
60 * \ingroup hash
61 * \defgroup hash_murmur3 Murmur3 Hash Implementation
62 */
63 /**@{*/
64
65
66 // Changes from Murmur3 distribution are marked with `//PDB'
67 //
68
69 /*************************************************
70 ** class Murmur3HashImplementation
71 ************************************************/
72
73 // Adapted from http://code.google.com/p/smhasher/
74
75 // Begin Murmur3.cpp -------- *NS_CHECK_STYLE_OFF* ---->
76
77 //
78 //-----------------------------------------------------------------------------
79 // MurmurHash3 was written by Austin Appleby, and is placed in the public
80 // domain. The author hereby disclaims copyright to this source code.
81
82 // Note - The x86 and x64 versions do _not_ produce the same results, as the
83 // algorithms are optimized for their respective platforms. You can still
84 // compile and run any of them on any platform, but your performance with the
85 // non-native version will be less than optimal.
86
87
88 /**
89 * Barrel shift (rotate) left on 32 bits.
90 *
91 * \param [in] x The initial value.
92 * \param [in] r The number of bit positions to rotate.
93 * \return The rotated value.
94 */
rotl32(uint32_t x,int8_t r)95 inline uint32_t rotl32 ( uint32_t x, int8_t r )
96 {
97 return (x << r) | (x >> (32 - r));
98 }
99
100 /**
101 * Barrel shift (rotate) left on 64 bits.
102 *
103 * \param [in] x The initial value.
104 * \param [in] r The number of bit positions to rotate.
105 * \return The rotated value.
106 */
rotl64(uint64_t x,int8_t r)107 inline uint64_t rotl64 ( uint64_t x, int8_t r )
108 {
109 return (x << r) | (x >> (64 - r));
110 }
111
112 /** Unsigned long long constants. */
113 #define BIG_CONSTANT(x) (x##LLU)
114
115 //-----------------------------------------------------------------------------
116 /**
117 * Block read
118 *
119 * If your platform needs to do endian-swapping or can only
120 * handle aligned reads, do the conversion here.
121 *
122 * \param [in] p Block base address.
123 * \param [in] i Index into the block.
124 * \returns The \c i'th word from the block.
125 */
getblock(const uint32_t * p,std::size_t i)126 inline uint32_t getblock ( const uint32_t * p, std::size_t i )
127 {
128 return p[i];
129 }
130 /** \copydoc getblock(const uint32_t*,std::size_t) */
getblock(const uint64_t * p,std::size_t i)131 inline uint64_t getblock ( const uint64_t * p, std::size_t i )
132 {
133 return p[i];
134 }
135
136 //-----------------------------------------------------------------------------
137 /**
138 * Finalization mix - force all bits of a hash block to avalanche.
139 *
140 * \param [in] h Final word of the hash block.
141 * \returns Fully mixed final word.
142 */
fmix(uint32_t h)143 inline uint32_t fmix ( uint32_t h )
144 {
145 h ^= h >> 16;
146 h *= 0x85ebca6b;
147 h ^= h >> 13;
148 h *= 0xc2b2ae35;
149 h ^= h >> 16;
150
151 return h;
152 }
153
154 //----------
155 /** \copydoc fmix(uint32_t) */
fmix(uint64_t h)156 inline uint64_t fmix ( uint64_t h )
157 {
158 h ^= h >> 33;
159 h *= BIG_CONSTANT(0xff51afd7ed558ccd);
160 h ^= h >> 33;
161 h *= BIG_CONSTANT(0xc4ceb9fe1a85ec53);
162 h ^= h >> 33;
163
164 return h;
165 }
166
167 //-----------------------------------------------------------------------------
168
169 //PDB forward
170 /**
171 * Initial and incremental hash.
172 *
173 * \param [in] key Data to be hashed.
174 * \param [in] len Number of words in the \c key.
175 * \param [in] seed Initial or current hash state.
176 * \param [out] out Output hash value.
177 */
178 void MurmurHash3_x86_32_incr ( const void * key, std::size_t len,
179 uint32_t seed, void * out );
180 /**
181 * Finalize a hash.
182 *
183 * \param [in] len Total number of words that have gone in to the hash.
184 * \param [in] seed Initial or current hash state.
185 * \param [out] out Output hash value.
186 */
187 void MurmurHash3_x86_32_fin ( std::size_t len,
188 uint32_t seed, void * out );
189
190 //PDB - incremental hashing
191 /** \copydoc MurmurHash3_x86_32_incr() */
MurmurHash3_x86_32(const void * key,std::size_t len,uint32_t seed,void * out)192 void MurmurHash3_x86_32 ( const void * key, std::size_t len,
193 uint32_t seed, void * out )
194 {
195 uint32_t h1;
196 MurmurHash3_x86_32_incr (key, len, seed, &h1);
197 MurmurHash3_x86_32_fin (len, h1, out);
198 }
199
MurmurHash3_x86_32_incr(const void * key,std::size_t len,uint32_t seed,void * out)200 void MurmurHash3_x86_32_incr ( const void * key, std::size_t len,
201 uint32_t seed, void * out )
202 {
203 const uint8_t * data = (const uint8_t*)key;
204 const std::size_t nblocks = len / 4; //PDB: was const int nblocks
205
206 uint32_t h1 = seed;
207
208 uint32_t c1 = 0xcc9e2d51;
209 uint32_t c2 = 0x1b873593;
210
211 //----------
212 // body
213
214 //PDB: const uint32_t * blocks = (const uint32_t *)(data + nblocks*4);
215 const uint32_t * blocks = (const uint32_t *)(data);
216
217 //PDB: for(int i = -nblocks; i; i++)
218 for(std::size_t i = 0; i < nblocks; i++)
219 {
220 uint32_t k1 = getblock(blocks,i);
221
222 k1 *= c1;
223 k1 = rotl32(k1,15);
224 k1 *= c2;
225
226 h1 ^= k1;
227 h1 = rotl32(h1,13);
228 h1 = h1*5+0xe6546b64;
229 }
230
231 //----------
232 // tail
233
234 const uint8_t * tail = (const uint8_t*)(data + nblocks*4);
235
236 uint32_t k1 = 0;
237
238 switch(len & 3)
239 {
240 case 3: k1 ^= tail[2] << 16;
241 case 2: k1 ^= tail[1] << 8;
242 case 1: k1 ^= tail[0];
243 k1 *= c1; k1 = rotl32(k1,15); k1 *= c2; h1 ^= k1;
244 };
245
246 *(uint32_t *)out = h1;
247 }
248
249 //PDB - incremental hashing - finalization
MurmurHash3_x86_32_fin(std::size_t len,uint32_t seed,void * out)250 void MurmurHash3_x86_32_fin ( std::size_t len,
251 uint32_t seed, void * out )
252 {
253 uint32_t h1 = seed;
254
255 //----------
256 // finalization
257
258 h1 ^= len;
259
260 h1 = fmix(h1);
261
262 *(uint32_t *)out = h1;
263 }
264
265 //-----------------------------------------------------------------------------
266
267 //PDB forward
268 /**
269 * Initial and incremental hash.
270 *
271 * \param [in] key Data to be hashed.
272 * \param [in] len Number of words in the \c key.
273 * \param [in] seeds Initial or current hash state.
274 * \param [out] out Output hash value.
275 */
276 void MurmurHash3_x86_128_incr ( const void * key, const std::size_t len,
277 uint32_t * seeds, void * out );
278 /**
279 * Finalize a hash.
280 *
281 * \param [in] len Total number of words that have gone in to the hash.
282 * \param [in] seeds Initial or current hash state.
283 * \param [out] out Output hash value.
284 */
285 void MurmurHash3_x86_128_fin ( const std::size_t len,
286 uint32_t * seeds, void * out );
287
288 //PDB - incremental hashing
289 /**
290 * Initial and incremental hash.
291 *
292 * \param [in] key Data to be hashed.
293 * \param [in] len Number of words in the \c key.
294 * \param [in] seed Initial or current hash state.
295 * \param [out] out Output hash value.
296 */
MurmurHash3_x86_128(const void * key,const std::size_t len,uint32_t seed,void * out)297 void MurmurHash3_x86_128 ( const void * key, const std::size_t len,
298 uint32_t seed, void * out )
299 {
300 uint32_t seeds[4];
301 uint32_t h[4];
302 seeds[0] = seeds[1] = seeds[2] = seeds[3] = seed;
303 MurmurHash3_x86_128_incr (key, len, seeds, h);
304 MurmurHash3_x86_128_fin (len, h, out);
305 }
306
MurmurHash3_x86_128_incr(const void * key,const std::size_t len,uint32_t * seeds,void * out)307 void MurmurHash3_x86_128_incr ( const void * key, const std::size_t len,
308 uint32_t * seeds, void * out )
309 {
310 const uint8_t * data = (const uint8_t*)key;
311 const std::size_t nblocks = len / 16; //PDB: was const int nblocks
312
313 uint32_t h1 = seeds[0];
314 uint32_t h2 = seeds[1];
315 uint32_t h3 = seeds[2];
316 uint32_t h4 = seeds[3];
317
318 uint32_t c1 = 0x239b961b;
319 uint32_t c2 = 0xab0e9789;
320 uint32_t c3 = 0x38b34ae5;
321 uint32_t c4 = 0xa1e38b93;
322
323 //----------
324 // body
325
326 //PDB: const uint32_t * blocks = (const uint32_t *)(data + nblocks*16);
327 const uint32_t * blocks = (const uint32_t *)(data);
328
329 //PDB: for(int i = -nblocks; i; i++)
330 for(std::size_t i = 0; i < nblocks; i++)
331 {
332 uint32_t k1 = getblock(blocks,i*4+0);
333 uint32_t k2 = getblock(blocks,i*4+1);
334 uint32_t k3 = getblock(blocks,i*4+2);
335 uint32_t k4 = getblock(blocks,i*4+3);
336
337 k1 *= c1; k1 = rotl32(k1,15); k1 *= c2; h1 ^= k1;
338
339 h1 = rotl32(h1,19); h1 += h2; h1 = h1*5+0x561ccd1b;
340
341 k2 *= c2; k2 = rotl32(k2,16); k2 *= c3; h2 ^= k2;
342
343 h2 = rotl32(h2,17); h2 += h3; h2 = h2*5+0x0bcaa747;
344
345 k3 *= c3; k3 = rotl32(k3,17); k3 *= c4; h3 ^= k3;
346
347 h3 = rotl32(h3,15); h3 += h4; h3 = h3*5+0x96cd1c35;
348
349 k4 *= c4; k4 = rotl32(k4,18); k4 *= c1; h4 ^= k4;
350
351 h4 = rotl32(h4,13); h4 += h1; h4 = h4*5+0x32ac3b17;
352 }
353
354 //----------
355 // tail
356
357 const uint8_t * tail = (const uint8_t*)(data + nblocks*16);
358
359 uint32_t k1 = 0;
360 uint32_t k2 = 0;
361 uint32_t k3 = 0;
362 uint32_t k4 = 0;
363
364 switch(len & 15)
365 {
366 case 15: k4 ^= tail[14] << 16;
367 case 14: k4 ^= tail[13] << 8;
368 case 13: k4 ^= tail[12] << 0;
369 k4 *= c4; k4 = rotl32(k4,18); k4 *= c1; h4 ^= k4;
370
371 case 12: k3 ^= tail[11] << 24;
372 case 11: k3 ^= tail[10] << 16;
373 case 10: k3 ^= tail[ 9] << 8;
374 case 9: k3 ^= tail[ 8] << 0;
375 k3 *= c3; k3 = rotl32(k3,17); k3 *= c4; h3 ^= k3;
376
377 case 8: k2 ^= tail[ 7] << 24;
378 case 7: k2 ^= tail[ 6] << 16;
379 case 6: k2 ^= tail[ 5] << 8;
380 case 5: k2 ^= tail[ 4] << 0;
381 k2 *= c2; k2 = rotl32(k2,16); k2 *= c3; h2 ^= k2;
382
383 case 4: k1 ^= tail[ 3] << 24;
384 case 3: k1 ^= tail[ 2] << 16;
385 case 2: k1 ^= tail[ 1] << 8;
386 case 1: k1 ^= tail[ 0] << 0;
387 k1 *= c1; k1 = rotl32(k1,15); k1 *= c2; h1 ^= k1;
388 };
389
390 ((uint32_t *)out)[0] = h1;
391 ((uint32_t *)out)[1] = h2;
392 ((uint32_t *)out)[2] = h3;
393 ((uint32_t *)out)[3] = h4;
394 }
395
396 //PDB - incremental hashing - finalization
MurmurHash3_x86_128_fin(const std::size_t len,uint32_t * seeds,void * out)397 void MurmurHash3_x86_128_fin ( const std::size_t len,
398 uint32_t * seeds, void * out )
399 {
400 //----------
401 // finalization
402
403 uint32_t h1 = seeds[0];
404 uint32_t h2 = seeds[1];
405 uint32_t h3 = seeds[2];
406 uint32_t h4 = seeds[3];
407
408 h1 ^= len; h2 ^= len; h3 ^= len; h4 ^= len;
409
410 h1 += h2; h1 += h3; h1 += h4;
411 h2 += h1; h3 += h1; h4 += h1;
412
413 h1 = fmix(h1);
414 h2 = fmix(h2);
415 h3 = fmix(h3);
416 h4 = fmix(h4);
417
418 h1 += h2; h1 += h3; h1 += h4;
419 h2 += h1; h3 += h1; h4 += h1;
420
421 ((uint32_t *)out)[0] = h1;
422 ((uint32_t *)out)[1] = h2;
423 ((uint32_t *)out)[2] = h3;
424 ((uint32_t *)out)[3] = h4;
425 }
426
427 //-----------------------------------------------------------------------------
428 /** \copydoc MurmurHash3_x86_32() */
MurmurHash3_x64_128(const void * key,const std::size_t len,const uint32_t seed,void * out)429 void MurmurHash3_x64_128 ( const void * key, const std::size_t len,
430 const uint32_t seed, void * out )
431 {
432 const uint8_t * data = (const uint8_t*)key;
433 const std::size_t nblocks = len / 16; //PDB: was const int nblocks
434
435 uint64_t h1 = seed;
436 uint64_t h2 = seed;
437
438 uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
439 uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);
440
441 //----------
442 // body
443
444 const uint64_t * blocks = (const uint64_t *)(data);
445
446 for(std::size_t i = 0; i < nblocks; i++) //PDB: was int i
447 {
448 uint64_t k1 = getblock(blocks,i*2+0);
449 uint64_t k2 = getblock(blocks,i*2+1);
450
451 k1 *= c1; k1 = rotl64(k1,31); k1 *= c2; h1 ^= k1;
452
453 h1 = rotl64(h1,27); h1 += h2; h1 = h1*5+0x52dce729;
454
455 k2 *= c2; k2 = rotl64(k2,33); k2 *= c1; h2 ^= k2;
456
457 h2 = rotl64(h2,31); h2 += h1; h2 = h2*5+0x38495ab5;
458 }
459
460 //----------
461 // tail
462
463 const uint8_t * tail = (const uint8_t*)(data + nblocks*16);
464
465 uint64_t k1 = 0;
466 uint64_t k2 = 0;
467
468 switch(len & 15)
469 {
470 case 15: k2 ^= uint64_t(tail[14]) << 48;
471 case 14: k2 ^= uint64_t(tail[13]) << 40;
472 case 13: k2 ^= uint64_t(tail[12]) << 32;
473 case 12: k2 ^= uint64_t(tail[11]) << 24;
474 case 11: k2 ^= uint64_t(tail[10]) << 16;
475 case 10: k2 ^= uint64_t(tail[ 9]) << 8;
476 case 9: k2 ^= uint64_t(tail[ 8]) << 0;
477 k2 *= c2; k2 = rotl64(k2,33); k2 *= c1; h2 ^= k2;
478
479 case 8: k1 ^= uint64_t(tail[ 7]) << 56;
480 case 7: k1 ^= uint64_t(tail[ 6]) << 48;
481 case 6: k1 ^= uint64_t(tail[ 5]) << 40;
482 case 5: k1 ^= uint64_t(tail[ 4]) << 32;
483 case 4: k1 ^= uint64_t(tail[ 3]) << 24;
484 case 3: k1 ^= uint64_t(tail[ 2]) << 16;
485 case 2: k1 ^= uint64_t(tail[ 1]) << 8;
486 case 1: k1 ^= uint64_t(tail[ 0]) << 0;
487 k1 *= c1; k1 = rotl64(k1,31); k1 *= c2; h1 ^= k1;
488 };
489
490 //----------
491 // finalization
492
493 h1 ^= len; h2 ^= len;
494
495 h1 += h2;
496 h2 += h1;
497
498 h1 = fmix(h1);
499 h2 = fmix(h2);
500
501 h1 += h2;
502 h2 += h1;
503
504 ((uint32_t *)out)[0] = static_cast<uint32_t> (h1); //PDB cast
505 ((uint32_t *)out)[1] = static_cast<uint32_t> (h2); //PDB cast
506 }
507
508
509 // End Murmur3.cpp ---------- *NS_CHECK_STYLE_ON* ----->
510
511 #undef BIG_CONSTANT
512
513
514 //-----------------------------------------------------------------------------
515
516
517 /**@}*/ // \defgroup hash_murmur3
518
519 } // namespace Murmur3Implementation
520
521
Murmur3()522 Murmur3::Murmur3 ()
523 {
524 clear ();
525 }
526
527 uint32_t
GetHash32(const char * buffer,const std::size_t size)528 Murmur3::GetHash32 (const char * buffer, const std::size_t size)
529 {
530 using namespace Murmur3Implementation;
531
532 MurmurHash3_x86_32_incr (buffer, size,
533 m_hash32, (void *) &m_hash32);
534 m_size32 += static_cast<uint32_t> (size);
535 uint32_t hash;
536 MurmurHash3_x86_32_fin (m_size32, m_hash32, (void *) &hash);
537
538 return hash;
539 }
540
541 uint64_t
GetHash64(const char * buffer,const std::size_t size)542 Murmur3::GetHash64 (const char * buffer, const std::size_t size)
543 {
544 using namespace Murmur3Implementation;
545
546 MurmurHash3_x86_128_incr (buffer, static_cast<int> (size),
547 (uint32_t *)(void *)m_hash64, m_hash64);
548 m_size64 += size;
549
550 // Simpler would be:
551 //
552 // uint64_t hash[2];
553 // MurmurHash3_x86_128_fin (m_size64, m_hash64, hash);
554 // return hash[0];
555 //
556 // but this triggers an aliasing bug in gcc-4.4 (perhaps related to
557 // http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39390).
558 // In ns-3, this bug produces incorrect results in static optimized
559 // builds only.
560 //
561 // Using uint32_t here avoids the bug, and continues to works with newer gcc.
562 uint32_t hash[4];
563
564 MurmurHash3_x86_128_fin (static_cast<int> (m_size64),
565 (uint32_t *)(void *)m_hash64, hash);
566 uint64_t result = hash[1];
567 result = (result << 32) | hash[0];
568 return result;
569 }
570
571 void
clear(void)572 Murmur3::clear (void)
573 {
574 m_hash32 = (uint32_t)SEED;
575 m_size32 = 0;
576 m_hash64[0] = m_hash64[1] = ((uint64_t)SEED << 32) | (uint32_t)SEED;
577 m_size64 = 0;
578 }
579
580 } // namespace Function
581
582 } // namespace Hash
583
584 } // namespace ns3
585