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Diffstat (limited to '')
-rw-r--r-- | fluent-bit/lib/librdkafka-2.1.0/src/rdrand.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/fluent-bit/lib/librdkafka-2.1.0/src/rdrand.c b/fluent-bit/lib/librdkafka-2.1.0/src/rdrand.c new file mode 100644 index 00000000..e36d7938 --- /dev/null +++ b/fluent-bit/lib/librdkafka-2.1.0/src/rdrand.c @@ -0,0 +1,70 @@ +/* + * librd - Rapid Development C library + * + * Copyright (c) 2012, Magnus Edenhill + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include "rd.h" +#include "rdrand.h" +#include "rdtime.h" +#include "tinycthread.h" + +int rd_jitter(int low, int high) { + int rand_num; +#if HAVE_RAND_R + static RD_TLS unsigned int seed = 0; + + /* Initial seed with time+thread id */ + if (unlikely(seed == 0)) { + struct timeval tv; + rd_gettimeofday(&tv, NULL); + seed = (unsigned int)(tv.tv_usec / 1000); + seed ^= (unsigned int)(intptr_t)thrd_current(); + } + + rand_num = rand_r(&seed); +#else + rand_num = rand(); +#endif + return (low + (rand_num % ((high - low) + 1))); +} + +void rd_array_shuffle(void *base, size_t nmemb, size_t entry_size) { + int i; + void *tmp = rd_alloca(entry_size); + + /* FIXME: Optimized version for word-sized entries. */ + + for (i = (int)nmemb - 1; i > 0; i--) { + int j = rd_jitter(0, i); + if (unlikely(i == j)) + continue; + + memcpy(tmp, (char *)base + (i * entry_size), entry_size); + memcpy((char *)base + (i * entry_size), + (char *)base + (j * entry_size), entry_size); + memcpy((char *)base + (j * entry_size), tmp, entry_size); + } +} |