//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under both the GPLv2 (found in the
//  COPYING file in the root directory) and Apache 2.0 License
//  (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2012 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.

#include <vector>

#include "test_util/testharness.h"
#include "util/hash.h"

// The hash algorithm is part of the file format, for example for the Bloom
// filters. Test that the hash values are stable for a set of random strings of
// varying lengths.
TEST(HashTest, Values) {
  using rocksdb::Hash;
  constexpr uint32_t kSeed = 0xbc9f1d34;  // Same as BloomHash.

  EXPECT_EQ(Hash("", 0, kSeed), 3164544308u);
  EXPECT_EQ(Hash("\x08", 1, kSeed), 422599524u);
  EXPECT_EQ(Hash("\x17", 1, kSeed), 3168152998u);
  EXPECT_EQ(Hash("\x9a", 1, kSeed), 3195034349u);
  EXPECT_EQ(Hash("\x1c", 1, kSeed), 2651681383u);
  EXPECT_EQ(Hash("\x4d\x76", 2, kSeed), 2447836956u);
  EXPECT_EQ(Hash("\x52\xd5", 2, kSeed), 3854228105u);
  EXPECT_EQ(Hash("\x91\xf7", 2, kSeed), 31066776u);
  EXPECT_EQ(Hash("\xd6\x27", 2, kSeed), 1806091603u);
  EXPECT_EQ(Hash("\x30\x46\x0b", 3, kSeed), 3808221797u);
  EXPECT_EQ(Hash("\x56\xdc\xd6", 3, kSeed), 2157698265u);
  EXPECT_EQ(Hash("\xd4\x52\x33", 3, kSeed), 1721992661u);
  EXPECT_EQ(Hash("\x6a\xb5\xf4", 3, kSeed), 2469105222u);
  EXPECT_EQ(Hash("\x67\x53\x81\x1c", 4, kSeed), 118283265u);
  EXPECT_EQ(Hash("\x69\xb8\xc0\x88", 4, kSeed), 3416318611u);
  EXPECT_EQ(Hash("\x1e\x84\xaf\x2d", 4, kSeed), 3315003572u);
  EXPECT_EQ(Hash("\x46\xdc\x54\xbe", 4, kSeed), 447346355u);
  EXPECT_EQ(Hash("\xd0\x7a\x6e\xea\x56", 5, kSeed), 4255445370u);
  EXPECT_EQ(Hash("\x86\x83\xd5\xa4\xd8", 5, kSeed), 2390603402u);
  EXPECT_EQ(Hash("\xb7\x46\xbb\x77\xce", 5, kSeed), 2048907743u);
  EXPECT_EQ(Hash("\x6c\xa8\xbc\xe5\x99", 5, kSeed), 2177978500u);
  EXPECT_EQ(Hash("\x5c\x5e\xe1\xa0\x73\x81", 6, kSeed), 1036846008u);
  EXPECT_EQ(Hash("\x08\x5d\x73\x1c\xe5\x2e", 6, kSeed), 229980482u);
  EXPECT_EQ(Hash("\x42\xfb\xf2\x52\xb4\x10", 6, kSeed), 3655585422u);
  EXPECT_EQ(Hash("\x73\xe1\xff\x56\x9c\xce", 6, kSeed), 3502708029u);
  EXPECT_EQ(Hash("\x5c\xbe\x97\x75\x54\x9a\x52", 7, kSeed), 815120748u);
  EXPECT_EQ(Hash("\x16\x82\x39\x49\x88\x2b\x36", 7, kSeed), 3056033698u);
  EXPECT_EQ(Hash("\x59\x77\xf0\xa7\x24\xf4\x78", 7, kSeed), 587205227u);
  EXPECT_EQ(Hash("\xd3\xa5\x7c\x0e\xc0\x02\x07", 7, kSeed), 2030937252u);
  EXPECT_EQ(Hash("\x31\x1b\x98\x75\x96\x22\xd3\x9a", 8, kSeed), 469635402u);
  EXPECT_EQ(Hash("\x38\xd6\xf7\x28\x20\xb4\x8a\xe9", 8, kSeed), 3530274698u);
  EXPECT_EQ(Hash("\xbb\x18\x5d\xf4\x12\x03\xf7\x99", 8, kSeed), 1974545809u);
  EXPECT_EQ(Hash("\x80\xd4\x3b\x3b\xae\x22\xa2\x78", 8, kSeed), 3563570120u);
  EXPECT_EQ(Hash("\x1a\xb5\xd0\xfe\xab\xc3\x61\xb2\x99", 9, kSeed),
            2706087434u);
  EXPECT_EQ(Hash("\x8e\x4a\xc3\x18\x20\x2f\x06\xe6\x3c", 9, kSeed),
            1534654151u);
  EXPECT_EQ(Hash("\xb6\xc0\xdd\x05\x3f\xc4\x86\x4c\xef", 9, kSeed),
            2355554696u);
  EXPECT_EQ(Hash("\x9a\x5f\x78\x0d\xaf\x50\xe1\x1f\x55", 9, kSeed),
            1400800912u);
  EXPECT_EQ(Hash("\x22\x6f\x39\x1f\xf8\xdd\x4f\x52\x17\x94", 10, kSeed),
            3420325137u);
  EXPECT_EQ(Hash("\x32\x89\x2a\x75\x48\x3a\x4a\x02\x69\xdd", 10, kSeed),
            3427803584u);
  EXPECT_EQ(Hash("\x06\x92\x5c\xf4\x88\x0e\x7e\x68\x38\x3e", 10, kSeed),
            1152407945u);
  EXPECT_EQ(Hash("\xbd\x2c\x63\x38\xbf\xe9\x78\xb7\xbf\x15", 10, kSeed),
            3382479516u);
}

TEST(Fastrange32Test, Values) {
  using rocksdb::fastrange32;
  // Zero range
  EXPECT_EQ(fastrange32(0, 0), 0U);
  EXPECT_EQ(fastrange32(123, 0), 0U);
  EXPECT_EQ(fastrange32(0xffffffff, 0), 0U);

  // One range
  EXPECT_EQ(fastrange32(0, 1), 0U);
  EXPECT_EQ(fastrange32(123, 1), 0U);
  EXPECT_EQ(fastrange32(0xffffffff, 1), 0U);

  // Two range
  EXPECT_EQ(fastrange32(0, 2), 0U);
  EXPECT_EQ(fastrange32(123, 2), 0U);
  EXPECT_EQ(fastrange32(0x7fffffff, 2), 0U);
  EXPECT_EQ(fastrange32(0x80000000, 2), 1U);
  EXPECT_EQ(fastrange32(0xffffffff, 2), 1U);

  // Seven range
  EXPECT_EQ(fastrange32(0, 7), 0U);
  EXPECT_EQ(fastrange32(123, 7), 0U);
  EXPECT_EQ(fastrange32(613566756, 7), 0U);
  EXPECT_EQ(fastrange32(613566757, 7), 1U);
  EXPECT_EQ(fastrange32(1227133513, 7), 1U);
  EXPECT_EQ(fastrange32(1227133514, 7), 2U);
  // etc.
  EXPECT_EQ(fastrange32(0xffffffff, 7), 6U);

  // Big
  EXPECT_EQ(fastrange32(1, 0x80000000), 0U);
  EXPECT_EQ(fastrange32(2, 0x80000000), 1U);
  EXPECT_EQ(fastrange32(4, 0x7fffffff), 1U);
  EXPECT_EQ(fastrange32(4, 0x80000000), 2U);
  EXPECT_EQ(fastrange32(0xffffffff, 0x7fffffff), 0x7ffffffeU);
  EXPECT_EQ(fastrange32(0xffffffff, 0x80000000), 0x7fffffffU);
}

TEST(Fastrange64Test, Values) {
  using rocksdb::fastrange64;
  // Zero range
  EXPECT_EQ(fastrange64(0, 0), 0U);
  EXPECT_EQ(fastrange64(123, 0), 0U);
  EXPECT_EQ(fastrange64(0xffffFFFF, 0), 0U);
  EXPECT_EQ(fastrange64(0xffffFFFFffffFFFF, 0), 0U);

  // One range
  EXPECT_EQ(fastrange64(0, 1), 0U);
  EXPECT_EQ(fastrange64(123, 1), 0U);
  EXPECT_EQ(fastrange64(0xffffFFFF, 1), 0U);
  EXPECT_EQ(fastrange64(0xffffFFFFffffFFFF, 1), 0U);

  // Two range
  EXPECT_EQ(fastrange64(0, 2), 0U);
  EXPECT_EQ(fastrange64(123, 2), 0U);
  EXPECT_EQ(fastrange64(0xffffFFFF, 2), 0U);
  EXPECT_EQ(fastrange64(0x7fffFFFFffffFFFF, 2), 0U);
  EXPECT_EQ(fastrange64(0x8000000000000000, 2), 1U);
  EXPECT_EQ(fastrange64(0xffffFFFFffffFFFF, 2), 1U);

  // Seven range
  EXPECT_EQ(fastrange64(0, 7), 0U);
  EXPECT_EQ(fastrange64(123, 7), 0U);
  EXPECT_EQ(fastrange64(0xffffFFFF, 7), 0U);
  EXPECT_EQ(fastrange64(2635249153387078802, 7), 0U);
  EXPECT_EQ(fastrange64(2635249153387078803, 7), 1U);
  EXPECT_EQ(fastrange64(5270498306774157604, 7), 1U);
  EXPECT_EQ(fastrange64(5270498306774157605, 7), 2U);
  EXPECT_EQ(fastrange64(0x7fffFFFFffffFFFF, 7), 3U);
  EXPECT_EQ(fastrange64(0x8000000000000000, 7), 3U);
  EXPECT_EQ(fastrange64(0xffffFFFFffffFFFF, 7), 6U);

  // Big but 32-bit range
  EXPECT_EQ(fastrange64(0x100000000, 0x80000000), 0U);
  EXPECT_EQ(fastrange64(0x200000000, 0x80000000), 1U);
  EXPECT_EQ(fastrange64(0x400000000, 0x7fffFFFF), 1U);
  EXPECT_EQ(fastrange64(0x400000000, 0x80000000), 2U);
  EXPECT_EQ(fastrange64(0xffffFFFFffffFFFF, 0x7fffFFFF), 0x7fffFFFEU);
  EXPECT_EQ(fastrange64(0xffffFFFFffffFFFF, 0x80000000), 0x7fffFFFFU);

  // Big, > 32-bit range
#if SIZE_MAX == UINT64_MAX
  EXPECT_EQ(fastrange64(0x7fffFFFFffffFFFF, 0x4200000002), 0x2100000000U);
  EXPECT_EQ(fastrange64(0x8000000000000000, 0x4200000002), 0x2100000001U);

  EXPECT_EQ(fastrange64(0x0000000000000000, 420000000002), 0U);
  EXPECT_EQ(fastrange64(0x7fffFFFFffffFFFF, 420000000002), 210000000000U);
  EXPECT_EQ(fastrange64(0x8000000000000000, 420000000002), 210000000001U);
  EXPECT_EQ(fastrange64(0xffffFFFFffffFFFF, 420000000002), 420000000001U);

  EXPECT_EQ(fastrange64(0xffffFFFFffffFFFF, 0xffffFFFFffffFFFF),
            0xffffFFFFffffFFFEU);
#endif
}

// for inspection of disassembly
uint32_t fastrange32(uint32_t hash, uint32_t range) {
  return rocksdb::fastrange32(hash, range);
}

// for inspection of disassembly
size_t fastrange64(uint64_t hash, size_t range) {
  return rocksdb::fastrange64(hash, range);
}

// for inspection of disassembly
uint64_t NPHash64(const char* data, size_t n) {
  return rocksdb::NPHash64(data, n);
}

int main(int argc, char** argv) {
  ::testing::InitGoogleTest(&argc, argv);

  return RUN_ALL_TESTS();
}