1 4545b700 2021-10-15 thomas /*
  2 4545b700 2021-10-15 thomas  *  Copyright (c) 2012-2019, Jyri J. Virkki
  3 4545b700 2021-10-15 thomas  *  All rights reserved.
  4 4545b700 2021-10-15 thomas  *
  5 4545b700 2021-10-15 thomas  * Redistribution and use in source and binary forms, with or without
  6 4545b700 2021-10-15 thomas  * modification, are permitted provided that the following conditions are
  7 4545b700 2021-10-15 thomas  * met:
  8 4545b700 2021-10-15 thomas  * 
  9 4545b700 2021-10-15 thomas  * 1. Redistributions of source code must retain the above copyright
 10 4545b700 2021-10-15 thomas  * notice, this list of conditions and the following disclaimer.
 11 4545b700 2021-10-15 thomas  * 
 12 4545b700 2021-10-15 thomas  * 2. Redistributions in binary form must reproduce the above copyright
 13 4545b700 2021-10-15 thomas  * notice, this list of conditions and the following disclaimer in the
 14 4545b700 2021-10-15 thomas  * documentation and/or other materials provided with the distribution.
 15 4545b700 2021-10-15 thomas  * 
 16 4545b700 2021-10-15 thomas  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 17 4545b700 2021-10-15 thomas  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 18 4545b700 2021-10-15 thomas  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 19 4545b700 2021-10-15 thomas  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 20 4545b700 2021-10-15 thomas  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 21 4545b700 2021-10-15 thomas  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 22 4545b700 2021-10-15 thomas  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 23 4545b700 2021-10-15 thomas  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 24 4545b700 2021-10-15 thomas  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 25 4545b700 2021-10-15 thomas  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 26 4545b700 2021-10-15 thomas  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 27 4545b700 2021-10-15 thomas  */
 28 4545b700 2021-10-15 thomas 
 29 4545b700 2021-10-15 thomas /* Obtained from https://github.com/jvirkki/libbloom */
 30 4545b700 2021-10-15 thomas 
 31 4545b700 2021-10-15 thomas /*
 32 4545b700 2021-10-15 thomas  * Refer to bloom.h for documentation on the public interfaces.
 33 4545b700 2021-10-15 thomas  */
 34 4545b700 2021-10-15 thomas 
 35 4545b700 2021-10-15 thomas #include <assert.h>
 36 4545b700 2021-10-15 thomas #include <fcntl.h>
 37 4545b700 2021-10-15 thomas #include <math.h>
 38 4545b700 2021-10-15 thomas #include <stdint.h>
 39 4545b700 2021-10-15 thomas #include <stdio.h>
 40 4545b700 2021-10-15 thomas #include <stdlib.h>
 41 4545b700 2021-10-15 thomas #include <string.h>
 42 4545b700 2021-10-15 thomas #include <sys/stat.h>
 43 4545b700 2021-10-15 thomas #include <sys/types.h>
 44 4545b700 2021-10-15 thomas #include <unistd.h>
 45 4545b700 2021-10-15 thomas 
 46 4545b700 2021-10-15 thomas #include "bloom.h"
 47 4545b700 2021-10-15 thomas #include "murmurhash2.h"
 48 4545b700 2021-10-15 thomas 
 49 4545b700 2021-10-15 thomas #define MAKESTRING(n) STRING(n)
 50 4545b700 2021-10-15 thomas #define STRING(n) #n
 51 4545b700 2021-10-15 thomas 
 52 4545b700 2021-10-15 thomas 
 53 4545b700 2021-10-15 thomas inline static int test_bit_set_bit(unsigned char * buf,
 54 4545b700 2021-10-15 thomas                                    unsigned int x, int set_bit)
 55 4545b700 2021-10-15 thomas {
 56 4545b700 2021-10-15 thomas   unsigned int byte = x >> 3;
 57 4545b700 2021-10-15 thomas   unsigned char c = buf[byte];        // expensive memory access
 58 4545b700 2021-10-15 thomas   unsigned int mask = 1 << (x % 8);
 59 4545b700 2021-10-15 thomas 
 60 4545b700 2021-10-15 thomas   if (c & mask) {
 61 4545b700 2021-10-15 thomas     return 1;
 62 4545b700 2021-10-15 thomas   } else {
 63 4545b700 2021-10-15 thomas     if (set_bit) {
 64 4545b700 2021-10-15 thomas       buf[byte] = c | mask;
 65 4545b700 2021-10-15 thomas     }
 66 4545b700 2021-10-15 thomas     return 0;
 67 4545b700 2021-10-15 thomas   }
 68 4545b700 2021-10-15 thomas }
 69 4545b700 2021-10-15 thomas 
 70 4545b700 2021-10-15 thomas 
 71 4545b700 2021-10-15 thomas static int bloom_check_add(struct bloom * bloom,
 72 4545b700 2021-10-15 thomas                            const void * buffer, int len, int add)
 73 4545b700 2021-10-15 thomas {
 74 4545b700 2021-10-15 thomas   if (bloom->ready == 0) {
 75 4545b700 2021-10-15 thomas     printf("bloom at %p not initialized!\n", (void *)bloom);
 76 4545b700 2021-10-15 thomas     return -1;
 77 4545b700 2021-10-15 thomas   }
 78 4545b700 2021-10-15 thomas 
 79 4545b700 2021-10-15 thomas   int hits = 0;
 80 cc524d36 2022-05-31 thomas   register unsigned int a = murmurhash2(buffer, len, bloom->seed);
 81 4545b700 2021-10-15 thomas   register unsigned int b = murmurhash2(buffer, len, a);
 82 4545b700 2021-10-15 thomas   register unsigned int x;
 83 4545b700 2021-10-15 thomas   register unsigned int i;
 84 4545b700 2021-10-15 thomas 
 85 4545b700 2021-10-15 thomas   for (i = 0; i < bloom->hashes; i++) {
 86 4545b700 2021-10-15 thomas     x = (a + i*b) % bloom->bits;
 87 4545b700 2021-10-15 thomas     if (test_bit_set_bit(bloom->bf, x, add)) {
 88 4545b700 2021-10-15 thomas       hits++;
 89 4545b700 2021-10-15 thomas     } else if (!add) {
 90 4545b700 2021-10-15 thomas       // Don't care about the presence of all the bits. Just our own.
 91 4545b700 2021-10-15 thomas       return 0;
 92 4545b700 2021-10-15 thomas     }
 93 4545b700 2021-10-15 thomas   }
 94 4545b700 2021-10-15 thomas 
 95 4545b700 2021-10-15 thomas   if (hits == bloom->hashes) {
 96 4545b700 2021-10-15 thomas     return 1;                // 1 == element already in (or collision)
 97 4545b700 2021-10-15 thomas   }
 98 4545b700 2021-10-15 thomas 
 99 4545b700 2021-10-15 thomas   return 0;
100 4545b700 2021-10-15 thomas }
101 4545b700 2021-10-15 thomas 
102 4545b700 2021-10-15 thomas 
103 4545b700 2021-10-15 thomas int bloom_init_size(struct bloom * bloom, int entries, double error,
104 4545b700 2021-10-15 thomas                     unsigned int cache_size)
105 4545b700 2021-10-15 thomas {
106 4545b700 2021-10-15 thomas   return bloom_init(bloom, entries, error);
107 4545b700 2021-10-15 thomas }
108 4545b700 2021-10-15 thomas 
109 4545b700 2021-10-15 thomas 
110 4545b700 2021-10-15 thomas int bloom_init(struct bloom * bloom, int entries, double error)
111 4545b700 2021-10-15 thomas {
112 4545b700 2021-10-15 thomas   bloom->ready = 0;
113 4545b700 2021-10-15 thomas 
114 cc524d36 2022-05-31 thomas   bloom->seed = arc4random();
115 cc524d36 2022-05-31 thomas 
116 4545b700 2021-10-15 thomas   if (entries < 1000 || error == 0) {
117 4545b700 2021-10-15 thomas     return 1;
118 4545b700 2021-10-15 thomas   }
119 4545b700 2021-10-15 thomas 
120 4545b700 2021-10-15 thomas   bloom->entries = entries;
121 4545b700 2021-10-15 thomas   bloom->error = error;
122 4545b700 2021-10-15 thomas 
123 4545b700 2021-10-15 thomas   double num = log(bloom->error);
124 4545b700 2021-10-15 thomas   double denom = 0.480453013918201; // ln(2)^2
125 4545b700 2021-10-15 thomas   bloom->bpe = -(num / denom);
126 4545b700 2021-10-15 thomas 
127 4545b700 2021-10-15 thomas   double dentries = (double)entries;
128 4545b700 2021-10-15 thomas   bloom->bits = (int)(dentries * bloom->bpe);
129 4545b700 2021-10-15 thomas 
130 4545b700 2021-10-15 thomas   if (bloom->bits % 8) {
131 4545b700 2021-10-15 thomas     bloom->bytes = (bloom->bits / 8) + 1;
132 4545b700 2021-10-15 thomas   } else {
133 4545b700 2021-10-15 thomas     bloom->bytes = bloom->bits / 8;
134 4545b700 2021-10-15 thomas   }
135 4545b700 2021-10-15 thomas 
136 4545b700 2021-10-15 thomas   bloom->hashes = (int)ceil(0.693147180559945 * bloom->bpe);  // ln(2)
137 4545b700 2021-10-15 thomas 
138 4545b700 2021-10-15 thomas   bloom->bf = (unsigned char *)calloc(bloom->bytes, sizeof(unsigned char));
139 4545b700 2021-10-15 thomas   if (bloom->bf == NULL) {                                   // LCOV_EXCL_START
140 4545b700 2021-10-15 thomas     return 1;
141 4545b700 2021-10-15 thomas   }                                                          // LCOV_EXCL_STOP
142 4545b700 2021-10-15 thomas 
143 4545b700 2021-10-15 thomas   bloom->ready = 1;
144 4545b700 2021-10-15 thomas   return 0;
145 4545b700 2021-10-15 thomas }
146 4545b700 2021-10-15 thomas 
147 4545b700 2021-10-15 thomas 
148 4545b700 2021-10-15 thomas int bloom_check(struct bloom * bloom, const void * buffer, int len)
149 4545b700 2021-10-15 thomas {
150 4545b700 2021-10-15 thomas   return bloom_check_add(bloom, buffer, len, 0);
151 4545b700 2021-10-15 thomas }
152 4545b700 2021-10-15 thomas 
153 4545b700 2021-10-15 thomas 
154 4545b700 2021-10-15 thomas int bloom_add(struct bloom * bloom, const void * buffer, int len)
155 4545b700 2021-10-15 thomas {
156 4545b700 2021-10-15 thomas   return bloom_check_add(bloom, buffer, len, 1);
157 4545b700 2021-10-15 thomas }
158 4545b700 2021-10-15 thomas 
159 4545b700 2021-10-15 thomas 
160 4545b700 2021-10-15 thomas void bloom_print(struct bloom * bloom)
161 4545b700 2021-10-15 thomas {
162 4545b700 2021-10-15 thomas   printf("bloom at %p\n", (void *)bloom);
163 4545b700 2021-10-15 thomas   printf(" ->entries = %d\n", bloom->entries);
164 4545b700 2021-10-15 thomas   printf(" ->error = %f\n", bloom->error);
165 4545b700 2021-10-15 thomas   printf(" ->bits = %d\n", bloom->bits);
166 4545b700 2021-10-15 thomas   printf(" ->bits per elem = %f\n", bloom->bpe);
167 4545b700 2021-10-15 thomas   printf(" ->bytes = %d\n", bloom->bytes);
168 4545b700 2021-10-15 thomas   printf(" ->hash functions = %d\n", bloom->hashes);
169 4545b700 2021-10-15 thomas }
170 4545b700 2021-10-15 thomas 
171 4545b700 2021-10-15 thomas 
172 4545b700 2021-10-15 thomas void bloom_free(struct bloom * bloom)
173 4545b700 2021-10-15 thomas {
174 4545b700 2021-10-15 thomas   if (bloom->ready) {
175 4545b700 2021-10-15 thomas     free(bloom->bf);
176 4545b700 2021-10-15 thomas   }
177 4545b700 2021-10-15 thomas   bloom->ready = 0;
178 4545b700 2021-10-15 thomas }
179 4545b700 2021-10-15 thomas 
180 4545b700 2021-10-15 thomas 
181 4545b700 2021-10-15 thomas int bloom_reset(struct bloom * bloom)
182 4545b700 2021-10-15 thomas {
183 4545b700 2021-10-15 thomas   if (!bloom->ready) return 1;
184 4545b700 2021-10-15 thomas   memset(bloom->bf, 0, bloom->bytes);
185 4545b700 2021-10-15 thomas   return 0;
186 4545b700 2021-10-15 thomas }