1 /*
2 * Copyright (c) 2009-2012, Pieter Noordhuis <pcnoordhuis at gmail dot com>
3 * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * * Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * * Neither the name of Redis nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without
16 * specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include "intset.h"
35 #include "zmalloc.h"
36 #include "endianconv.h"
37
38 /* Note that these encodings are ordered, so:
39 * INTSET_ENC_INT16 < INTSET_ENC_INT32 < INTSET_ENC_INT64. */
40 #define INTSET_ENC_INT16 (sizeof(int16_t))
41 #define INTSET_ENC_INT32 (sizeof(int32_t))
42 #define INTSET_ENC_INT64 (sizeof(int64_t))
43
44 /* Return the required encoding for the provided value. */
_intsetValueEncoding(int64_t v)45 static uint8_t _intsetValueEncoding(int64_t v) {
46 if (v < INT32_MIN || v > INT32_MAX)
47 return INTSET_ENC_INT64;
48 else if (v < INT16_MIN || v > INT16_MAX)
49 return INTSET_ENC_INT32;
50 else
51 return INTSET_ENC_INT16;
52 }
53
54 /* Return the value at pos, given an encoding. */
_intsetGetEncoded(intset * is,int pos,uint8_t enc)55 static int64_t _intsetGetEncoded(intset *is, int pos, uint8_t enc) {
56 int64_t v64;
57 int32_t v32;
58 int16_t v16;
59
60 if (enc == INTSET_ENC_INT64) {
61 memcpy(&v64,((int64_t*)is->contents)+pos,sizeof(v64));
62 memrev64ifbe(&v64);
63 return v64;
64 } else if (enc == INTSET_ENC_INT32) {
65 memcpy(&v32,((int32_t*)is->contents)+pos,sizeof(v32));
66 memrev32ifbe(&v32);
67 return v32;
68 } else {
69 memcpy(&v16,((int16_t*)is->contents)+pos,sizeof(v16));
70 memrev16ifbe(&v16);
71 return v16;
72 }
73 }
74
75 /* Return the value at pos, using the configured encoding. */
_intsetGet(intset * is,int pos)76 static int64_t _intsetGet(intset *is, int pos) {
77 return _intsetGetEncoded(is,pos,intrev32ifbe(is->encoding));
78 }
79
80 /* Set the value at pos, using the configured encoding. */
_intsetSet(intset * is,int pos,int64_t value)81 static void _intsetSet(intset *is, int pos, int64_t value) {
82 uint32_t encoding = intrev32ifbe(is->encoding);
83
84 if (encoding == INTSET_ENC_INT64) {
85 ((int64_t*)is->contents)[pos] = value;
86 memrev64ifbe(((int64_t*)is->contents)+pos);
87 } else if (encoding == INTSET_ENC_INT32) {
88 ((int32_t*)is->contents)[pos] = value;
89 memrev32ifbe(((int32_t*)is->contents)+pos);
90 } else {
91 ((int16_t*)is->contents)[pos] = value;
92 memrev16ifbe(((int16_t*)is->contents)+pos);
93 }
94 }
95
96 /* Create an empty intset. */
intsetNew(void)97 intset *intsetNew(void) {
98 intset *is = zmalloc(sizeof(intset));
99 is->encoding = intrev32ifbe(INTSET_ENC_INT16);
100 is->length = 0;
101 return is;
102 }
103
104 /* Resize the intset */
intsetResize(intset * is,uint32_t len)105 static intset *intsetResize(intset *is, uint32_t len) {
106 uint32_t size = len*intrev32ifbe(is->encoding);
107 is = zrealloc(is,sizeof(intset)+size);
108 return is;
109 }
110
111 /* Search for the position of "value". Return 1 when the value was found and
112 * sets "pos" to the position of the value within the intset. Return 0 when
113 * the value is not present in the intset and sets "pos" to the position
114 * where "value" can be inserted. */
intsetSearch(intset * is,int64_t value,uint32_t * pos)115 static uint8_t intsetSearch(intset *is, int64_t value, uint32_t *pos) {
116 int min = 0, max = intrev32ifbe(is->length)-1, mid = -1;
117 int64_t cur = -1;
118
119 /* The value can never be found when the set is empty */
120 if (intrev32ifbe(is->length) == 0) {
121 if (pos) *pos = 0;
122 return 0;
123 } else {
124 /* Check for the case where we know we cannot find the value,
125 * but do know the insert position. */
126 if (value > _intsetGet(is,intrev32ifbe(is->length)-1)) {
127 if (pos) *pos = intrev32ifbe(is->length);
128 return 0;
129 } else if (value < _intsetGet(is,0)) {
130 if (pos) *pos = 0;
131 return 0;
132 }
133 }
134
135 while(max >= min) {
136 mid = ((unsigned int)min + (unsigned int)max) >> 1;
137 cur = _intsetGet(is,mid);
138 if (value > cur) {
139 min = mid+1;
140 } else if (value < cur) {
141 max = mid-1;
142 } else {
143 break;
144 }
145 }
146
147 if (value == cur) {
148 if (pos) *pos = mid;
149 return 1;
150 } else {
151 if (pos) *pos = min;
152 return 0;
153 }
154 }
155
156 /* Upgrades the intset to a larger encoding and inserts the given integer. */
intsetUpgradeAndAdd(intset * is,int64_t value)157 static intset *intsetUpgradeAndAdd(intset *is, int64_t value) {
158 uint8_t curenc = intrev32ifbe(is->encoding);
159 uint8_t newenc = _intsetValueEncoding(value);
160 int length = intrev32ifbe(is->length);
161 int prepend = value < 0 ? 1 : 0;
162
163 /* First set new encoding and resize */
164 is->encoding = intrev32ifbe(newenc);
165 is = intsetResize(is,intrev32ifbe(is->length)+1);
166
167 /* Upgrade back-to-front so we don't overwrite values.
168 * Note that the "prepend" variable is used to make sure we have an empty
169 * space at either the beginning or the end of the intset. */
170 while(length--)
171 _intsetSet(is,length+prepend,_intsetGetEncoded(is,length,curenc));
172
173 /* Set the value at the beginning or the end. */
174 if (prepend)
175 _intsetSet(is,0,value);
176 else
177 _intsetSet(is,intrev32ifbe(is->length),value);
178 is->length = intrev32ifbe(intrev32ifbe(is->length)+1);
179 return is;
180 }
181
intsetMoveTail(intset * is,uint32_t from,uint32_t to)182 static void intsetMoveTail(intset *is, uint32_t from, uint32_t to) {
183 void *src, *dst;
184 uint32_t bytes = intrev32ifbe(is->length)-from;
185 uint32_t encoding = intrev32ifbe(is->encoding);
186
187 if (encoding == INTSET_ENC_INT64) {
188 src = (int64_t*)is->contents+from;
189 dst = (int64_t*)is->contents+to;
190 bytes *= sizeof(int64_t);
191 } else if (encoding == INTSET_ENC_INT32) {
192 src = (int32_t*)is->contents+from;
193 dst = (int32_t*)is->contents+to;
194 bytes *= sizeof(int32_t);
195 } else {
196 src = (int16_t*)is->contents+from;
197 dst = (int16_t*)is->contents+to;
198 bytes *= sizeof(int16_t);
199 }
200 memmove(dst,src,bytes);
201 }
202
203 /* Insert an integer in the intset */
intsetAdd(intset * is,int64_t value,uint8_t * success)204 intset *intsetAdd(intset *is, int64_t value, uint8_t *success) {
205 uint8_t valenc = _intsetValueEncoding(value);
206 uint32_t pos;
207 if (success) *success = 1;
208
209 /* Upgrade encoding if necessary. If we need to upgrade, we know that
210 * this value should be either appended (if > 0) or prepended (if < 0),
211 * because it lies outside the range of existing values. */
212 if (valenc > intrev32ifbe(is->encoding)) {
213 /* This always succeeds, so we don't need to curry *success. */
214 return intsetUpgradeAndAdd(is,value);
215 } else {
216 /* Abort if the value is already present in the set.
217 * This call will populate "pos" with the right position to insert
218 * the value when it cannot be found. */
219 if (intsetSearch(is,value,&pos)) {
220 if (success) *success = 0;
221 return is;
222 }
223
224 is = intsetResize(is,intrev32ifbe(is->length)+1);
225 if (pos < intrev32ifbe(is->length)) intsetMoveTail(is,pos,pos+1);
226 }
227
228 _intsetSet(is,pos,value);
229 is->length = intrev32ifbe(intrev32ifbe(is->length)+1);
230 return is;
231 }
232
233 /* Delete integer from intset */
intsetRemove(intset * is,int64_t value,int * success)234 intset *intsetRemove(intset *is, int64_t value, int *success) {
235 uint8_t valenc = _intsetValueEncoding(value);
236 uint32_t pos;
237 if (success) *success = 0;
238
239 if (valenc <= intrev32ifbe(is->encoding) && intsetSearch(is,value,&pos)) {
240 uint32_t len = intrev32ifbe(is->length);
241
242 /* We know we can delete */
243 if (success) *success = 1;
244
245 /* Overwrite value with tail and update length */
246 if (pos < (len-1)) intsetMoveTail(is,pos+1,pos);
247 is = intsetResize(is,len-1);
248 is->length = intrev32ifbe(len-1);
249 }
250 return is;
251 }
252
253 /* Determine whether a value belongs to this set */
intsetFind(intset * is,int64_t value)254 uint8_t intsetFind(intset *is, int64_t value) {
255 uint8_t valenc = _intsetValueEncoding(value);
256 return valenc <= intrev32ifbe(is->encoding) && intsetSearch(is,value,NULL);
257 }
258
259 /* Return random member */
intsetRandom(intset * is)260 int64_t intsetRandom(intset *is) {
261 return _intsetGet(is,rand()%intrev32ifbe(is->length));
262 }
263
264 /* Sets the value to the value at the given position. When this position is
265 * out of range the function returns 0, when in range it returns 1. */
intsetGet(intset * is,uint32_t pos,int64_t * value)266 uint8_t intsetGet(intset *is, uint32_t pos, int64_t *value) {
267 if (pos < intrev32ifbe(is->length)) {
268 *value = _intsetGet(is,pos);
269 return 1;
270 }
271 return 0;
272 }
273
274 /* Return intset length */
intsetLen(intset * is)275 uint32_t intsetLen(intset *is) {
276 return intrev32ifbe(is->length);
277 }
278
279 /* Return intset blob size in bytes. */
intsetBlobLen(intset * is)280 size_t intsetBlobLen(intset *is) {
281 return sizeof(intset)+intrev32ifbe(is->length)*intrev32ifbe(is->encoding);
282 }
283
284 #ifdef REDIS_TEST
285 #include <sys/time.h>
286 #include <time.h>
287
288 #if 0
289 static void intsetRepr(intset *is) {
290 for (uint32_t i = 0; i < intrev32ifbe(is->length); i++) {
291 printf("%lld\n", (uint64_t)_intsetGet(is,i));
292 }
293 printf("\n");
294 }
295
296 static void error(char *err) {
297 printf("%s\n", err);
298 exit(1);
299 }
300 #endif
301
ok(void)302 static void ok(void) {
303 printf("OK\n");
304 }
305
usec(void)306 static long long usec(void) {
307 struct timeval tv;
308 gettimeofday(&tv,NULL);
309 return (((long long)tv.tv_sec)*1000000)+tv.tv_usec;
310 }
311
312 #define assert(_e) ((_e)?(void)0:(_assert(#_e,__FILE__,__LINE__),exit(1)))
_assert(char * estr,char * file,int line)313 static void _assert(char *estr, char *file, int line) {
314 printf("\n\n=== ASSERTION FAILED ===\n");
315 printf("==> %s:%d '%s' is not true\n",file,line,estr);
316 }
317
createSet(int bits,int size)318 static intset *createSet(int bits, int size) {
319 uint64_t mask = (1<<bits)-1;
320 uint64_t value;
321 intset *is = intsetNew();
322
323 for (int i = 0; i < size; i++) {
324 if (bits > 32) {
325 value = (rand()*rand()) & mask;
326 } else {
327 value = rand() & mask;
328 }
329 is = intsetAdd(is,value,NULL);
330 }
331 return is;
332 }
333
checkConsistency(intset * is)334 static void checkConsistency(intset *is) {
335 for (uint32_t i = 0; i < (intrev32ifbe(is->length)-1); i++) {
336 uint32_t encoding = intrev32ifbe(is->encoding);
337
338 if (encoding == INTSET_ENC_INT16) {
339 int16_t *i16 = (int16_t*)is->contents;
340 assert(i16[i] < i16[i+1]);
341 } else if (encoding == INTSET_ENC_INT32) {
342 int32_t *i32 = (int32_t*)is->contents;
343 assert(i32[i] < i32[i+1]);
344 } else {
345 int64_t *i64 = (int64_t*)is->contents;
346 assert(i64[i] < i64[i+1]);
347 }
348 }
349 }
350
351 #define UNUSED(x) (void)(x)
intsetTest(int argc,char ** argv)352 int intsetTest(int argc, char **argv) {
353 uint8_t success;
354 int i;
355 intset *is;
356 srand(time(NULL));
357
358 UNUSED(argc);
359 UNUSED(argv);
360
361 printf("Value encodings: "); {
362 assert(_intsetValueEncoding(-32768) == INTSET_ENC_INT16);
363 assert(_intsetValueEncoding(+32767) == INTSET_ENC_INT16);
364 assert(_intsetValueEncoding(-32769) == INTSET_ENC_INT32);
365 assert(_intsetValueEncoding(+32768) == INTSET_ENC_INT32);
366 assert(_intsetValueEncoding(-2147483648) == INTSET_ENC_INT32);
367 assert(_intsetValueEncoding(+2147483647) == INTSET_ENC_INT32);
368 assert(_intsetValueEncoding(-2147483649) == INTSET_ENC_INT64);
369 assert(_intsetValueEncoding(+2147483648) == INTSET_ENC_INT64);
370 assert(_intsetValueEncoding(-9223372036854775808ull) ==
371 INTSET_ENC_INT64);
372 assert(_intsetValueEncoding(+9223372036854775807ull) ==
373 INTSET_ENC_INT64);
374 ok();
375 }
376
377 printf("Basic adding: "); {
378 is = intsetNew();
379 is = intsetAdd(is,5,&success); assert(success);
380 is = intsetAdd(is,6,&success); assert(success);
381 is = intsetAdd(is,4,&success); assert(success);
382 is = intsetAdd(is,4,&success); assert(!success);
383 ok();
384 }
385
386 printf("Large number of random adds: "); {
387 uint32_t inserts = 0;
388 is = intsetNew();
389 for (i = 0; i < 1024; i++) {
390 is = intsetAdd(is,rand()%0x800,&success);
391 if (success) inserts++;
392 }
393 assert(intrev32ifbe(is->length) == inserts);
394 checkConsistency(is);
395 ok();
396 }
397
398 printf("Upgrade from int16 to int32: "); {
399 is = intsetNew();
400 is = intsetAdd(is,32,NULL);
401 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT16);
402 is = intsetAdd(is,65535,NULL);
403 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT32);
404 assert(intsetFind(is,32));
405 assert(intsetFind(is,65535));
406 checkConsistency(is);
407
408 is = intsetNew();
409 is = intsetAdd(is,32,NULL);
410 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT16);
411 is = intsetAdd(is,-65535,NULL);
412 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT32);
413 assert(intsetFind(is,32));
414 assert(intsetFind(is,-65535));
415 checkConsistency(is);
416 ok();
417 }
418
419 printf("Upgrade from int16 to int64: "); {
420 is = intsetNew();
421 is = intsetAdd(is,32,NULL);
422 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT16);
423 is = intsetAdd(is,4294967295,NULL);
424 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT64);
425 assert(intsetFind(is,32));
426 assert(intsetFind(is,4294967295));
427 checkConsistency(is);
428
429 is = intsetNew();
430 is = intsetAdd(is,32,NULL);
431 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT16);
432 is = intsetAdd(is,-4294967295,NULL);
433 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT64);
434 assert(intsetFind(is,32));
435 assert(intsetFind(is,-4294967295));
436 checkConsistency(is);
437 ok();
438 }
439
440 printf("Upgrade from int32 to int64: "); {
441 is = intsetNew();
442 is = intsetAdd(is,65535,NULL);
443 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT32);
444 is = intsetAdd(is,4294967295,NULL);
445 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT64);
446 assert(intsetFind(is,65535));
447 assert(intsetFind(is,4294967295));
448 checkConsistency(is);
449
450 is = intsetNew();
451 is = intsetAdd(is,65535,NULL);
452 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT32);
453 is = intsetAdd(is,-4294967295,NULL);
454 assert(intrev32ifbe(is->encoding) == INTSET_ENC_INT64);
455 assert(intsetFind(is,65535));
456 assert(intsetFind(is,-4294967295));
457 checkConsistency(is);
458 ok();
459 }
460
461 printf("Stress lookups: "); {
462 long num = 100000, size = 10000;
463 int i, bits = 20;
464 long long start;
465 is = createSet(bits,size);
466 checkConsistency(is);
467
468 start = usec();
469 for (i = 0; i < num; i++) intsetSearch(is,rand() % ((1<<bits)-1),NULL);
470 printf("%ld lookups, %ld element set, %lldusec\n",
471 num,size,usec()-start);
472 }
473
474 printf("Stress add+delete: "); {
475 int i, v1, v2;
476 is = intsetNew();
477 for (i = 0; i < 0xffff; i++) {
478 v1 = rand() % 0xfff;
479 is = intsetAdd(is,v1,NULL);
480 assert(intsetFind(is,v1));
481
482 v2 = rand() % 0xfff;
483 is = intsetRemove(is,v2,NULL);
484 assert(!intsetFind(is,v2));
485 }
486 checkConsistency(is);
487 ok();
488 }
489
490 return 0;
491 }
492 #endif
493