109 lines
2.9 KiB
C++
109 lines
2.9 KiB
C++
/* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */
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// First include (the generated) my_config.h, to get correct platform defines.
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#include "my_config.h"
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#include <gtest/gtest.h>
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#include "my_murmur3.h"
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/*
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Putting everything in a namespace prevents any (unintentional)
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name clashes with the code under test.
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*/
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namespace murmur3_unittest {
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/* Simple test checking that hash for fixed key has correct value. */
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TEST(Murmur3, Basic)
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{
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const char *str= "To be, or not to be, that is the question;";
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uint hash= murmur3_32((uchar*)str, strlen(str), 0);
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EXPECT_EQ(2385370181U, hash);
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}
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/* Test for empty key. */
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TEST(Murmur3, Empty)
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{
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uint hash= murmur3_32(NULL, 0, 0);
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EXPECT_EQ(0U, hash);
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}
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/*
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Test that shows that when we hash zero-keys of different length we
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get different results. Our my_hash_sort_bin is not good at that.
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*/
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TEST(Murmur3, Zeroes)
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{
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uchar buff[32];
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memset(buff, 0, sizeof(buff));
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uint hash1= murmur3_32(buff, sizeof(buff)/2, 0);
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uint hash2= murmur3_32(buff, sizeof(buff), 0);
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EXPECT_NE(hash1, hash2);
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}
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/* Test that seed matters. */
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TEST(Murmur3, Seed)
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{
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const char *str= "Whether 'tis nobler in the mind to suffer";
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uint hash1= murmur3_32((uchar *)str, strlen(str), 0);
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uint hash2= murmur3_32((uchar *)str, strlen(str), 1);
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EXPECT_NE(hash1, hash2);
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}
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/*
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Test for bug #16396598 "MDL HASH CAN STILL BE CONCURRENCY BOTTLENECK".
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Hashes for 8 keys from the bug report should have sufficiently different
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lower bits, so corresponding MDL objects won't fall into the same MDL map
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partitions.
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*/
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TEST(Murmur3, Bug16396598)
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{
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const char keys[8][14]= {"\002test\000sbtest1", "\002test\000sbtest2",
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"\002test\000sbtest3", "\002test\000sbtest4",
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"\002test\000sbtest5", "\002test\000sbtest6",
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"\002test\000sbtest7", "\002test\000sbtest8" };
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/* Array for number of keys falling into n-th bucket. */
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uint buckets[8];
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int i;
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memset(buckets, 0, sizeof(buckets));
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for (i= 0; i < 8; ++i)
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buckets[murmur3_32((const uchar *)keys[i], sizeof(keys[0]), 0) % 8]++;
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/*
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It is OK for a few keys to fall into the same bucket.
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But not for the half of the keys.
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*/
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for (i= 0; i < 8; ++i)
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EXPECT_GT(4U, buckets[i]);
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}
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} // namespace
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