Commit | Line | Data |
---|---|---|
819dc7d4 | 1 | /* |
ab5be9fa | 2 | * Copyright (C) 2006 Bob Jenkins |
21cf9b6b | 3 | * Copyright (C) 2011 EfficiOS Inc. |
ab5be9fa | 4 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
819dc7d4 | 5 | * |
c922647d | 6 | * SPDX-License-Identifier: LGPL-2.1-only |
66c60361 | 7 | * |
66c60361 DG |
8 | */ |
9 | ||
10 | /* | |
819dc7d4 DG |
11 | * These are functions for producing 32-bit hashes for hash table lookup. |
12 | * hashword(), hashlittle(), hashlittle2(), hashbig(), mix(), and final() are | |
13 | * externally useful functions. Routines to test the hash are included if | |
14 | * SELF_TEST is defined. You can use this free for any purpose. It's in the | |
15 | * public domain. It has no warranty. | |
16 | * | |
17 | * You probably want to use hashlittle(). hashlittle() and hashbig() hash byte | |
18 | * arrays. hashlittle() is is faster than hashbig() on little-endian machines. | |
19 | * Intel and AMD are little-endian machines. On second thought, you probably | |
20 | * want hashlittle2(), which is identical to hashlittle() except it returns two | |
21 | * 32-bit hashes for the price of one. You could implement hashbig2() if you | |
22 | * wanted but I haven't bothered here. | |
23 | * | |
24 | * If you want to find a hash of, say, exactly 7 integers, do | |
25 | * a = i1; b = i2; c = i3; | |
26 | * mix(a,b,c); | |
27 | * a += i4; b += i5; c += i6; | |
28 | * mix(a,b,c); | |
29 | * a += i7; | |
30 | * final(a,b,c); | |
31 | * then use c as the hash value. If you have a variable length array of | |
32 | * 4-byte integers to hash, use hashword(). If you have a byte array (like | |
33 | * a character string), use hashlittle(). If you have several byte arrays, or | |
34 | * a mix of things, see the comments above hashlittle(). | |
35 | * | |
36 | * Why is this so big? I read 12 bytes at a time into 3 4-byte integers, then | |
37 | * mix those integers. This is fast (you can do a lot more thorough mixing | |
38 | * with 12*3 instructions on 3 integers than you can with 3 instructions on 1 | |
39 | * byte), but shoehorning those bytes into integers efficiently is messy. | |
40 | */ | |
890d8fe4 | 41 | |
6c1c0768 | 42 | #define _LGPL_SOURCE |
c9e313bc | 43 | #include "utils.hpp" |
28ab034a | 44 | |
c9e313bc | 45 | #include <common/common.hpp> |
28ab034a | 46 | #include <common/compat/endian.hpp> /* attempt to define endianness */ |
c9e313bc | 47 | #include <common/hashtable/hashtable.hpp> |
bec39940 | 48 | |
28ab034a JG |
49 | #include <stdint.h> /* defines uint32_t etc */ |
50 | #include <stdio.h> /* defines printf for tests */ | |
51 | #include <string.h> | |
52 | #include <sys/param.h> /* attempt to define endianness */ | |
53 | #include <time.h> /* defines time_t for timings in the test */ | |
54 | #include <urcu/compiler.h> | |
55 | ||
819dc7d4 DG |
56 | /* |
57 | * My best guess at if you are big-endian or little-endian. This may | |
58 | * need adjustment. | |
59 | */ | |
28ab034a JG |
60 | #if (defined(BYTE_ORDER) && defined(LITTLE_ENDIAN) && BYTE_ORDER == LITTLE_ENDIAN) || \ |
61 | (defined(i386) || defined(__i386__) || defined(__i486__) || defined(__i586__) || \ | |
62 | 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) && BYTE_ORDER == BIG_ENDIAN) || \ | |
66 | (defined(sparc) || defined(POWERPC) || defined(mc68000) || defined(sel)) | |
67 | #define HASH_LITTLE_ENDIAN 0 | |
68 | #define HASH_BIG_ENDIAN 1 | |
819dc7d4 | 69 | #else |
28ab034a JG |
70 | #define HASH_LITTLE_ENDIAN 0 |
71 | #define HASH_BIG_ENDIAN 0 | |
819dc7d4 DG |
72 | #endif |
73 | ||
28ab034a JG |
74 | #define hashsize(n) ((uint32_t) 1 << (n)) |
75 | #define hashmask(n) (hashsize(n) - 1) | |
76 | #define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k)))) | |
819dc7d4 DG |
77 | |
78 | /* | |
79 | * mix -- mix 3 32-bit values reversibly. | |
80 | * | |
81 | * This is reversible, so any information in (a,b,c) before mix() is | |
82 | * still in (a,b,c) after mix(). | |
83 | * | |
84 | * If four pairs of (a,b,c) inputs are run through mix(), or through | |
85 | * mix() in reverse, there are at least 32 bits of the output that | |
86 | * are sometimes the same for one pair and different for another pair. | |
87 | * This was tested for: | |
88 | * * pairs that differed by one bit, by two bits, in any combination | |
89 | * of top bits of (a,b,c), or in any combination of bottom bits of | |
90 | * (a,b,c). | |
91 | * * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed | |
92 | * the output delta to a Gray code (a^(a>>1)) so a string of 1's (as | |
93 | * is commonly produced by subtraction) look like a single 1-bit | |
94 | * difference. | |
95 | * * the base values were pseudorandom, all zero but one bit set, or | |
96 | * all zero plus a counter that starts at zero. | |
97 | * | |
98 | * Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that | |
99 | * satisfy this are | |
100 | * 4 6 8 16 19 4 | |
101 | * 9 15 3 18 27 15 | |
102 | * 14 9 3 7 17 3 | |
103 | * Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing | |
104 | * for "differ" defined as + with a one-bit base and a two-bit delta. I | |
105 | * used http://burtleburtle.net/bob/hash/avalanche.html to choose | |
106 | * the operations, constants, and arrangements of the variables. | |
107 | * | |
108 | * This does not achieve avalanche. There are input bits of (a,b,c) | |
109 | * that fail to affect some output bits of (a,b,c), especially of a. The | |
110 | * most thoroughly mixed value is c, but it doesn't really even achieve | |
111 | * avalanche in c. | |
112 | * | |
113 | * This allows some parallelism. Read-after-writes are good at doubling | |
114 | * the number of bits affected, so the goal of mixing pulls in the opposite | |
115 | * direction as the goal of parallelism. I did what I could. Rotates | |
116 | * seem to cost as much as shifts on every machine I could lay my hands | |
117 | * on, and rotates are much kinder to the top and bottom bits, so I used | |
118 | * rotates. | |
119 | */ | |
5c7248cd JG |
120 | #define mix(a, b, c) \ |
121 | { \ | |
122 | (a) -= (c); \ | |
123 | (a) ^= rot(c, 4); \ | |
124 | (c) += (b); \ | |
125 | (b) -= (a); \ | |
126 | (b) ^= rot(a, 6); \ | |
127 | (a) += (c); \ | |
128 | (c) -= (b); \ | |
129 | (c) ^= rot(b, 8); \ | |
130 | (b) += (a); \ | |
131 | (a) -= (c); \ | |
132 | (a) ^= rot(c, 16); \ | |
133 | (c) += (b); \ | |
134 | (b) -= (a); \ | |
135 | (b) ^= rot(a, 19); \ | |
136 | (a) += (c); \ | |
137 | (c) -= (b); \ | |
138 | (c) ^= rot(b, 4); \ | |
139 | (b) += (a); \ | |
28ab034a | 140 | } |
819dc7d4 DG |
141 | |
142 | /* | |
143 | * final -- final mixing of 3 32-bit values (a,b,c) into c | |
144 | * | |
145 | * Pairs of (a,b,c) values differing in only a few bits will usually | |
146 | * produce values of c that look totally different. This was tested for | |
147 | * * pairs that differed by one bit, by two bits, in any combination | |
148 | * of top bits of (a,b,c), or in any combination of bottom bits of | |
149 | * (a,b,c). | |
150 | * * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed | |
151 | * the output delta to a Gray code (a^(a>>1)) so a string of 1's (as | |
152 | * is commonly produced by subtraction) look like a single 1-bit | |
153 | * difference. | |
154 | * * the base values were pseudorandom, all zero but one bit set, or | |
155 | * all zero plus a counter that starts at zero. | |
156 | * | |
157 | * These constants passed: | |
158 | * 14 11 25 16 4 14 24 | |
159 | * 12 14 25 16 4 14 24 | |
160 | * and these came close: | |
161 | * 4 8 15 26 3 22 24 | |
162 | * 10 8 15 26 3 22 24 | |
163 | * 11 8 15 26 3 22 24 | |
164 | */ | |
5c7248cd JG |
165 | #define final(a, b, c) \ |
166 | { \ | |
167 | (c) ^= (b); \ | |
168 | (c) -= rot(b, 14); \ | |
169 | (a) ^= (c); \ | |
170 | (a) -= rot(c, 11); \ | |
171 | (b) ^= (a); \ | |
172 | (b) -= rot(a, 25); \ | |
173 | (c) ^= (b); \ | |
174 | (c) -= rot(b, 16); \ | |
175 | (a) ^= (c); \ | |
176 | (a) -= rot(c, 4); \ | |
177 | (b) ^= (a); \ | |
178 | (b) -= rot(a, 14); \ | |
179 | (c) ^= (b); \ | |
180 | (c) -= rot(b, 24); \ | |
28ab034a | 181 | } |
819dc7d4 | 182 | |
bec39940 DG |
183 | /* |
184 | * k - the key, an array of uint32_t values | |
185 | * length - the length of the key, in uint32_ts | |
186 | * initval - the previous hash, or an arbitrary value | |
187 | */ | |
28ab034a | 188 | static uint32_t __attribute__((unused)) hashword(const uint32_t *k, size_t length, uint32_t initval) |
0df502fd MD |
189 | { |
190 | uint32_t a, b, c; | |
191 | ||
192 | /* Set up the internal state */ | |
193 | a = b = c = 0xdeadbeef + (((uint32_t) length) << 2) + initval; | |
194 | ||
195 | /*----------------------------------------- handle most of the key */ | |
196 | while (length > 3) { | |
197 | a += k[0]; | |
198 | b += k[1]; | |
199 | c += k[2]; | |
200 | mix(a, b, c); | |
201 | length -= 3; | |
202 | k += 3; | |
203 | } | |
204 | ||
205 | /*----------------------------------- handle the last 3 uint32_t's */ | |
28ab034a JG |
206 | switch (length) { /* all the case statements fall through */ |
207 | case 3: | |
208 | c += k[2]; /* fall through */ | |
209 | case 2: | |
210 | b += k[1]; /* fall through */ | |
211 | case 1: | |
212 | a += k[0]; | |
0df502fd | 213 | final(a, b, c); |
28ab034a | 214 | case 0: /* case 0: nothing left to add */ |
0df502fd MD |
215 | break; |
216 | } | |
217 | /*---------------------------------------------- report the result */ | |
218 | return c; | |
219 | } | |
220 | ||
819dc7d4 DG |
221 | /* |
222 | * hashword2() -- same as hashword(), but take two seeds and return two 32-bit | |
223 | * values. pc and pb must both be nonnull, and *pc and *pb must both be | |
224 | * initialized with seeds. If you pass in (*pb)==0, the output (*pc) will be | |
225 | * the same as the return value from hashword(). | |
226 | */ | |
28ab034a JG |
227 | static void __attribute__((unused)) |
228 | hashword2(const uint32_t *k, size_t length, uint32_t *pc, uint32_t *pb) | |
819dc7d4 DG |
229 | { |
230 | uint32_t a, b, c; | |
231 | ||
232 | /* Set up the internal state */ | |
233 | a = b = c = 0xdeadbeef + ((uint32_t) (length << 2)) + *pc; | |
234 | c += *pb; | |
235 | ||
236 | while (length > 3) { | |
237 | a += k[0]; | |
238 | b += k[1]; | |
239 | c += k[2]; | |
240 | mix(a, b, c); | |
241 | length -= 3; | |
242 | k += 3; | |
243 | } | |
244 | ||
245 | switch (length) { | |
28ab034a | 246 | case 3: |
819dc7d4 | 247 | c += k[2]; |
30eb3927 | 248 | /* fall through */ |
28ab034a | 249 | case 2: |
819dc7d4 | 250 | b += k[1]; |
30eb3927 | 251 | /* fall through */ |
28ab034a | 252 | case 1: |
819dc7d4 DG |
253 | a += k[0]; |
254 | final(a, b, c); | |
30eb3927 | 255 | /* fall through */ |
28ab034a | 256 | case 0: /* case 0: nothing left to add */ |
819dc7d4 DG |
257 | break; |
258 | } | |
259 | ||
260 | *pc = c; | |
261 | *pb = b; | |
262 | } | |
263 | ||
264 | /* | |
265 | * hashlittle() -- hash a variable-length key into a 32-bit value | |
266 | * k : the key (the unaligned variable-length array of bytes) | |
267 | * length : the length of the key, counting by bytes | |
268 | * initval : can be any 4-byte value | |
269 | * Returns a 32-bit value. Every bit of the key affects every bit of | |
270 | * the return value. Two keys differing by one or two bits will have | |
271 | * totally different hash values. | |
272 | * | |
273 | * The best hash table sizes are powers of 2. There is no need to do | |
274 | * mod a prime (mod is sooo slow!). If you need less than 32 bits, | |
275 | * use a bitmask. For example, if you need only 10 bits, do | |
276 | * h = (h & hashmask(10)); | |
277 | * In which case, the hash table should have hashsize(10) elements. | |
278 | * | |
279 | * If you are hashing n strings (uint8_t **)k, do it like this: | |
280 | * for (i=0, h=0; i<n; ++i) h = hashlittle( k[i], len[i], h); | |
281 | * | |
282 | * By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this | |
283 | * code any way you wish, private, educational, or commercial. It's free. | |
284 | * | |
285 | * Use for hash table lookup, or anything where one collision in 2^^32 is | |
286 | * acceptable. Do NOT use for cryptographic purposes. | |
287 | */ | |
1405051a | 288 | LTTNG_NO_SANITIZE_ADDRESS |
28ab034a | 289 | __attribute__((unused)) static uint32_t hashlittle(const void *key, size_t length, uint32_t initval) |
819dc7d4 | 290 | { |
28ab034a | 291 | uint32_t a, b, c; |
819dc7d4 DG |
292 | union { |
293 | const void *ptr; | |
294 | size_t i; | |
28ab034a | 295 | } u; /* needed for Mac Powerbook G4 */ |
819dc7d4 DG |
296 | |
297 | /* Set up the internal state */ | |
28ab034a | 298 | a = b = c = 0xdeadbeef + ((uint32_t) length) + initval; |
819dc7d4 DG |
299 | |
300 | u.ptr = key; | |
301 | if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) { | |
28ab034a | 302 | const uint32_t *k = (const uint32_t *) key; /* read 32-bit chunks */ |
819dc7d4 DG |
303 | |
304 | /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */ | |
305 | while (length > 12) { | |
306 | a += k[0]; | |
307 | b += k[1]; | |
308 | c += k[2]; | |
28ab034a | 309 | mix(a, b, c); |
819dc7d4 DG |
310 | length -= 12; |
311 | k += 3; | |
312 | } | |
313 | ||
314 | /* | |
315 | * "k[2]&0xffffff" actually reads beyond the end of the string, but | |
316 | * then masks off the part it's not allowed to read. Because the | |
317 | * string is aligned, the masked-off tail is in the same word as the | |
318 | * rest of the string. Every machine with memory protection I've seen | |
319 | * does it on word boundaries, so is OK with this. But VALGRIND will | |
320 | * still catch it and complain. The masking trick does make the hash | |
321 | * noticably faster for short strings (like English words). | |
322 | */ | |
323 | #ifndef VALGRIND | |
324 | ||
325 | switch (length) { | |
28ab034a JG |
326 | case 12: |
327 | c += k[2]; | |
328 | b += k[1]; | |
329 | a += k[0]; | |
330 | break; | |
331 | case 11: | |
332 | c += k[2] & 0xffffff; | |
333 | b += k[1]; | |
334 | a += k[0]; | |
335 | break; | |
336 | case 10: | |
337 | c += k[2] & 0xffff; | |
338 | b += k[1]; | |
339 | a += k[0]; | |
340 | break; | |
341 | case 9: | |
342 | c += k[2] & 0xff; | |
343 | b += k[1]; | |
344 | a += k[0]; | |
345 | break; | |
346 | case 8: | |
347 | b += k[1]; | |
348 | a += k[0]; | |
349 | break; | |
350 | case 7: | |
351 | b += k[1] & 0xffffff; | |
352 | a += k[0]; | |
353 | break; | |
354 | case 6: | |
355 | b += k[1] & 0xffff; | |
356 | a += k[0]; | |
357 | break; | |
358 | case 5: | |
359 | b += k[1] & 0xff; | |
360 | a += k[0]; | |
361 | break; | |
362 | case 4: | |
363 | a += k[0]; | |
364 | break; | |
365 | case 3: | |
366 | a += k[0] & 0xffffff; | |
367 | break; | |
368 | case 2: | |
369 | a += k[0] & 0xffff; | |
370 | break; | |
371 | case 1: | |
372 | a += k[0] & 0xff; | |
373 | break; | |
374 | case 0: | |
375 | return c; /* zero length strings require no mixing */ | |
819dc7d4 DG |
376 | } |
377 | #else /* make valgrind happy */ | |
378 | const uint8_t *k8; | |
379 | ||
28ab034a | 380 | k8 = (const uint8_t *) k; |
819dc7d4 | 381 | switch (length) { |
28ab034a JG |
382 | case 12: |
383 | c += k[2]; | |
384 | b += k[1]; | |
385 | a += k[0]; | |
386 | break; | |
387 | case 11: | |
388 | c += ((uint32_t) k8[10]) << 16; /* fall through */ | |
389 | case 10: | |
390 | c += ((uint32_t) k8[9]) << 8; /* fall through */ | |
391 | case 9: | |
392 | c += k8[8]; /* fall through */ | |
393 | case 8: | |
394 | b += k[1]; | |
395 | a += k[0]; | |
396 | break; | |
397 | case 7: | |
398 | b += ((uint32_t) k8[6]) << 16; /* fall through */ | |
399 | case 6: | |
400 | b += ((uint32_t) k8[5]) << 8; /* fall through */ | |
401 | case 5: | |
402 | b += k8[4]; /* fall through */ | |
403 | case 4: | |
404 | a += k[0]; | |
405 | break; | |
406 | case 3: | |
407 | a += ((uint32_t) k8[2]) << 16; /* fall through */ | |
408 | case 2: | |
409 | a += ((uint32_t) k8[1]) << 8; /* fall through */ | |
410 | case 1: | |
411 | a += k8[0]; | |
412 | break; | |
413 | case 0: | |
414 | return c; | |
819dc7d4 DG |
415 | } |
416 | #endif /* !valgrind */ | |
417 | } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) { | |
28ab034a | 418 | const uint16_t *k = (const uint16_t *) key; /* read 16-bit chunks */ |
819dc7d4 DG |
419 | const uint8_t *k8; |
420 | ||
421 | /*--------------- all but last block: aligned reads and different mixing */ | |
422 | while (length > 12) { | |
28ab034a JG |
423 | a += k[0] + (((uint32_t) k[1]) << 16); |
424 | b += k[2] + (((uint32_t) k[3]) << 16); | |
425 | c += k[4] + (((uint32_t) k[5]) << 16); | |
426 | mix(a, b, c); | |
819dc7d4 DG |
427 | length -= 12; |
428 | k += 6; | |
429 | } | |
430 | ||
28ab034a | 431 | k8 = (const uint8_t *) k; |
819dc7d4 DG |
432 | switch (length) { |
433 | case 12: | |
28ab034a JG |
434 | c += k[4] + (((uint32_t) k[5]) << 16); |
435 | b += k[2] + (((uint32_t) k[3]) << 16); | |
436 | a += k[0] + (((uint32_t) k[1]) << 16); | |
819dc7d4 DG |
437 | break; |
438 | case 11: | |
28ab034a | 439 | c += ((uint32_t) k8[10]) << 16; /* fall through */ |
819dc7d4 | 440 | case 10: |
28ab034a JG |
441 | c += k[4]; |
442 | b += k[2] + (((uint32_t) k[3]) << 16); | |
443 | a += k[0] + (((uint32_t) k[1]) << 16); | |
819dc7d4 DG |
444 | break; |
445 | case 9: | |
28ab034a | 446 | c += k8[8]; /* fall through */ |
819dc7d4 | 447 | case 8: |
28ab034a JG |
448 | b += k[2] + (((uint32_t) k[3]) << 16); |
449 | a += k[0] + (((uint32_t) k[1]) << 16); | |
819dc7d4 DG |
450 | break; |
451 | case 7: | |
28ab034a | 452 | b += ((uint32_t) k8[6]) << 16; /* fall through */ |
819dc7d4 | 453 | case 6: |
28ab034a JG |
454 | b += k[2]; |
455 | a += k[0] + (((uint32_t) k[1]) << 16); | |
819dc7d4 DG |
456 | break; |
457 | case 5: | |
28ab034a | 458 | b += k8[4]; /* fall through */ |
819dc7d4 | 459 | case 4: |
28ab034a | 460 | a += k[0] + (((uint32_t) k[1]) << 16); |
819dc7d4 DG |
461 | break; |
462 | case 3: | |
28ab034a | 463 | a += ((uint32_t) k8[2]) << 16; /* fall through */ |
819dc7d4 | 464 | case 2: |
28ab034a | 465 | a += k[0]; |
819dc7d4 DG |
466 | break; |
467 | case 1: | |
28ab034a | 468 | a += k8[0]; |
819dc7d4 DG |
469 | break; |
470 | case 0: | |
28ab034a | 471 | return c; /* zero length requires no mixing */ |
819dc7d4 DG |
472 | } |
473 | ||
28ab034a JG |
474 | } else { /* need to read the key one byte at a time */ |
475 | const uint8_t *k = (const uint8_t *) key; | |
819dc7d4 DG |
476 | |
477 | while (length > 12) { | |
478 | a += k[0]; | |
28ab034a JG |
479 | a += ((uint32_t) k[1]) << 8; |
480 | a += ((uint32_t) k[2]) << 16; | |
481 | a += ((uint32_t) k[3]) << 24; | |
819dc7d4 | 482 | b += k[4]; |
28ab034a JG |
483 | b += ((uint32_t) k[5]) << 8; |
484 | b += ((uint32_t) k[6]) << 16; | |
485 | b += ((uint32_t) k[7]) << 24; | |
819dc7d4 | 486 | c += k[8]; |
28ab034a JG |
487 | c += ((uint32_t) k[9]) << 8; |
488 | c += ((uint32_t) k[10]) << 16; | |
489 | c += ((uint32_t) k[11]) << 24; | |
490 | mix(a, b, c); | |
819dc7d4 DG |
491 | length -= 12; |
492 | k += 12; | |
493 | } | |
494 | ||
28ab034a JG |
495 | switch (length) { /* all the case statements fall through */ |
496 | case 12: | |
497 | c += ((uint32_t) k[11]) << 24; /* fall through */ | |
498 | case 11: | |
499 | c += ((uint32_t) k[10]) << 16; /* fall through */ | |
500 | case 10: | |
501 | c += ((uint32_t) k[9]) << 8; /* fall through */ | |
502 | case 9: | |
503 | c += k[8]; /* fall through */ | |
504 | case 8: | |
505 | b += ((uint32_t) k[7]) << 24; /* fall through */ | |
506 | case 7: | |
507 | b += ((uint32_t) k[6]) << 16; /* fall through */ | |
508 | case 6: | |
509 | b += ((uint32_t) k[5]) << 8; /* fall through */ | |
510 | case 5: | |
511 | b += k[4]; /* fall through */ | |
512 | case 4: | |
513 | a += ((uint32_t) k[3]) << 24; /* fall through */ | |
514 | case 3: | |
515 | a += ((uint32_t) k[2]) << 16; /* fall through */ | |
516 | case 2: | |
517 | a += ((uint32_t) k[1]) << 8; /* fall through */ | |
819dc7d4 | 518 | case 1: |
28ab034a | 519 | a += k[0]; |
819dc7d4 DG |
520 | break; |
521 | case 0: | |
522 | return c; | |
523 | } | |
524 | } | |
525 | ||
28ab034a | 526 | final(a, b, c); |
819dc7d4 DG |
527 | return c; |
528 | } | |
529 | ||
bcd52dd9 | 530 | unsigned long hash_key_u64(const void *_key, unsigned long seed) |
0df502fd MD |
531 | { |
532 | union { | |
533 | uint64_t v64; | |
534 | uint32_t v32[2]; | |
535 | } v; | |
536 | union { | |
537 | uint64_t v64; | |
538 | uint32_t v32[2]; | |
539 | } key; | |
540 | ||
0df502fd | 541 | v.v64 = (uint64_t) seed; |
bcd52dd9 | 542 | key.v64 = *(const uint64_t *) _key; |
0df502fd MD |
543 | hashword2(key.v32, 2, &v.v32[0], &v.v32[1]); |
544 | return v.v64; | |
545 | } | |
d88aee68 DG |
546 | |
547 | #if (CAA_BITS_PER_LONG == 64) | |
548 | /* | |
549 | * Hash function for number value. | |
9a2746aa | 550 | * Pass the value itself as the key, not its address. |
d88aee68 | 551 | */ |
bcd52dd9 | 552 | unsigned long hash_key_ulong(const void *_key, unsigned long seed) |
d88aee68 DG |
553 | { |
554 | uint64_t __key = (uint64_t) _key; | |
555 | return (unsigned long) hash_key_u64(&__key, seed); | |
556 | } | |
0df502fd | 557 | #else |
819dc7d4 DG |
558 | /* |
559 | * Hash function for number value. | |
9a2746aa | 560 | * Pass the value itself as the key, not its address. |
819dc7d4 | 561 | */ |
bcd52dd9 | 562 | unsigned long hash_key_ulong(const void *_key, unsigned long seed) |
819dc7d4 | 563 | { |
8da9ba32 | 564 | uint32_t key = (uint32_t) _key; |
0df502fd | 565 | |
0df502fd | 566 | return hashword(&key, 1, seed); |
819dc7d4 | 567 | } |
bec39940 | 568 | #endif /* CAA_BITS_PER_LONG */ |
819dc7d4 DG |
569 | |
570 | /* | |
571 | * Hash function for string. | |
572 | */ | |
bcd52dd9 | 573 | unsigned long hash_key_str(const void *key, unsigned long seed) |
819dc7d4 | 574 | { |
bcd52dd9 | 575 | return hashlittle(key, strlen((const char *) key), seed); |
819dc7d4 DG |
576 | } |
577 | ||
3c4599b9 JD |
578 | /* |
579 | * Hash function for two uint64_t. | |
580 | */ | |
bcd52dd9 | 581 | unsigned long hash_key_two_u64(const void *key, unsigned long seed) |
3c4599b9 | 582 | { |
28ab034a | 583 | const struct lttng_ht_two_u64 *k = (const struct lttng_ht_two_u64 *) key; |
3c4599b9 JD |
584 | |
585 | return hash_key_u64(&k->key1, seed) ^ hash_key_u64(&k->key2, seed); | |
586 | } | |
587 | ||
819dc7d4 DG |
588 | /* |
589 | * Hash function compare for number value. | |
590 | */ | |
bcd52dd9 | 591 | int hash_match_key_ulong(const void *key1, const void *key2) |
819dc7d4 | 592 | { |
819dc7d4 | 593 | if (key1 == key2) { |
bec39940 | 594 | return 1; |
819dc7d4 DG |
595 | } |
596 | ||
bec39940 | 597 | return 0; |
819dc7d4 DG |
598 | } |
599 | ||
d88aee68 DG |
600 | /* |
601 | * Hash function compare for number value. | |
602 | */ | |
bcd52dd9 | 603 | int hash_match_key_u64(const void *key1, const void *key2) |
d88aee68 | 604 | { |
bcd52dd9 | 605 | if (*(const uint64_t *) key1 == *(const uint64_t *) key2) { |
d88aee68 DG |
606 | return 1; |
607 | } | |
608 | ||
609 | return 0; | |
610 | } | |
611 | ||
819dc7d4 DG |
612 | /* |
613 | * Hash compare function for string. | |
614 | */ | |
bcd52dd9 | 615 | int hash_match_key_str(const void *key1, const void *key2) |
819dc7d4 | 616 | { |
6dca8ba7 | 617 | if (strcmp((const char *) key1, (const char *) key2) == 0) { |
bec39940 | 618 | return 1; |
819dc7d4 DG |
619 | } |
620 | ||
bec39940 | 621 | return 0; |
819dc7d4 | 622 | } |
3c4599b9 JD |
623 | |
624 | /* | |
625 | * Hash function compare two uint64_t. | |
626 | */ | |
bcd52dd9 | 627 | int hash_match_key_two_u64(const void *key1, const void *key2) |
3c4599b9 | 628 | { |
28ab034a JG |
629 | const struct lttng_ht_two_u64 *k1 = (const struct lttng_ht_two_u64 *) key1; |
630 | const struct lttng_ht_two_u64 *k2 = (const struct lttng_ht_two_u64 *) key2; | |
3c4599b9 | 631 | |
28ab034a | 632 | if (hash_match_key_u64(&k1->key1, &k2->key1) && hash_match_key_u64(&k1->key2, &k2->key2)) { |
3c4599b9 JD |
633 | return 1; |
634 | } | |
635 | ||
636 | return 0; | |
637 | } |