+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2013 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include "util.h"
-#include "siphash24.h"
-#include "bus-bloom.h"
-
-static inline void set_bit(uint64_t filter[], unsigned long b) {
- filter[b >> 6] |= 1ULL << (b & 63);
-}
-
-static const sd_id128_t hash_keys[] = {
- SD_ID128_ARRAY(b9,66,0b,f0,46,70,47,c1,88,75,c4,9c,54,b9,bd,15),
- SD_ID128_ARRAY(aa,a1,54,a2,e0,71,4b,39,bf,e1,dd,2e,9f,c5,4a,3b),
- SD_ID128_ARRAY(63,fd,ae,be,cd,82,48,12,a1,6e,41,26,cb,fa,a0,c8),
- SD_ID128_ARRAY(23,be,45,29,32,d2,46,2d,82,03,52,28,fe,37,17,f5),
- SD_ID128_ARRAY(56,3b,bf,ee,5a,4f,43,39,af,aa,94,08,df,f0,fc,10),
- SD_ID128_ARRAY(31,80,c8,73,c7,ea,46,d3,aa,25,75,0f,9e,4c,09,29),
- SD_ID128_ARRAY(7d,f7,18,4b,7b,a4,44,d5,85,3c,06,e0,65,53,96,6d),
- SD_ID128_ARRAY(f2,77,e9,6f,93,b5,4e,71,9a,0c,34,88,39,25,bf,35),
-};
-
-static void bloom_add_data(
- uint64_t filter[], /* The filter bits */
- size_t size, /* Size of the filter in bytes */
- unsigned k, /* Number of hash functions */
- const void *data, /* Data to hash */
- size_t n) { /* Size of data to hash in bytes */
-
- uint8_t h[8];
- uint64_t m;
- unsigned w, i, c = 0;
- unsigned hash_index;
-
- assert(size > 0);
- assert(k > 0);
-
- /* Determine bits in filter */
- m = size * 8;
-
- /* Determine how many bytes we need to generate a bit index 0..m for this filter */
- w = (u64log2(m) + 7) / 8;
-
- assert(w <= sizeof(uint64_t));
-
- /* Make sure we have enough hash keys to generate m * k bits
- * of hash value. Note that SipHash24 generates 64 bits of
- * hash value for each 128 bits of hash key. */
- assert(k * w <= ELEMENTSOF(hash_keys) * 8);
-
- for (i = 0, hash_index = 0; i < k; i++) {
- uint64_t p = 0;
- unsigned d;
-
- for (d = 0; d < w; d++) {
- if (c <= 0) {
- siphash24(h, data, n, hash_keys[hash_index++].bytes);
- c += 8;
- }
-
- p = (p << 8ULL) | (uint64_t) h[8 - c];
- c--;
- }
-
- p &= m - 1;
- set_bit(filter, p);
- }
-
- /* log_debug("bloom: adding <%.*s>", (int) n, (char*) data); */
-}
-
-void bloom_add_pair(uint64_t filter[], size_t size, unsigned k, const char *a, const char *b) {
- size_t n;
- char *c;
-
- assert(filter);
- assert(a);
- assert(b);
-
- n = strlen(a) + 1 + strlen(b);
- c = alloca(n + 1);
- strcpy(stpcpy(stpcpy(c, a), ":"), b);
-
- bloom_add_data(filter, size, k, c, n);
-}
-
-void bloom_add_prefixes(uint64_t filter[], size_t size, unsigned k, const char *a, const char *b, char sep) {
- size_t n;
- char *c, *p;
-
- assert(filter);
- assert(a);
- assert(b);
-
- n = strlen(a) + 1 + strlen(b);
- c = alloca(n + 1);
-
- p = stpcpy(stpcpy(c, a), ":");
- strcpy(p, b);
-
- for (;;) {
- char *e;
-
- e = strrchr(p, sep);
- if (!e || e == p)
- break;
-
- *e = 0;
- bloom_add_data(filter, size, k, c, e - c);
- }
-}
-
-bool bloom_validate_parameters(size_t size, unsigned k) {
- uint64_t m;
- unsigned w;
-
- if (size <= 0)
- return false;
-
- if (k <= 0)
- return false;
-
- m = size * 8;
- w = (u64log2(m) + 7) / 8;
- if (w > sizeof(uint64_t))
- return false;
-
- if (k * w > ELEMENTSOF(hash_keys) * 8)
- return false;
-
- return true;
-}
~ianmdlvl / elogind.git / blobdiff