Genericize and clean up FastRange (#7436)

Summary:
A generic algorithm in progress depends on a templatized
version of fastrange, so this change generalizes it and renames
it to fit our style guidelines, FastRange32, FastRange64, and now
FastRangeGeneric.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7436

Test Plan: added a few more test cases

Reviewed By: jay-zhuang

Differential Revision: D23958153

Pulled By: pdillinger

fbshipit-source-id: 8c3b76101653417804997e5f076623a25586f3e8
main
Peter Dillinger 4 years ago committed by Facebook GitHub Bot
parent 8f8264032d
commit 08552b19d3
  1. 2
      cache/cache_bench.cc
  2. 2
      db/memtable.cc
  3. 2
      memtable/hash_linklist_rep.cc
  4. 3
      trace_replay/block_cache_tracer.cc
  5. 8
      util/bloom_impl.h
  6. 8
      util/dynamic_bloom.h
  7. 112
      util/fastrange.h
  8. 6
      util/filter_bench.cc
  9. 50
      util/hash.h
  10. 157
      util/hash_test.cc
  11. 4
      util/math.h
  12. 2
      utilities/transactions/optimistic_transaction.cc
  13. 2
      utilities/transactions/transaction_lock_mgr.cc

@ -136,7 +136,7 @@ struct KeyGen {
for (uint32_t i = 0; i < FLAGS_skew; ++i) {
raw = std::min(raw, rnd.Next());
}
uint64_t key = fastrange64(raw, max_key);
uint64_t key = FastRange64(raw, max_key);
// Variable size and alignment
size_t off = key % 8;
key_data[0] = char{42};

@ -454,7 +454,7 @@ FragmentedRangeTombstoneIterator* MemTable::NewRangeTombstoneIterator(
}
port::RWMutex* MemTable::GetLock(const Slice& key) {
return &locks_[fastrange64(GetSliceNPHash64(key), locks_.size())];
return &locks_[GetSliceRangedNPHash(key, locks_.size())];
}
MemTable::MemTableStats MemTable::ApproximateStats(const Slice& start_ikey,

@ -218,7 +218,7 @@ class HashLinkListRep : public MemTableRep {
}
size_t GetHash(const Slice& slice) const {
return fastrange64(GetSliceNPHash64(slice), bucket_size_);
return GetSliceRangedNPHash(slice, bucket_size_);
}
Pointer* GetBucket(size_t i) const {

@ -26,8 +26,7 @@ bool ShouldTrace(const Slice& block_key, const TraceOptions& trace_options) {
}
// We use spatial downsampling so that we have a complete access history for a
// block.
return 0 == fastrange64(GetSliceNPHash64(block_key),
trace_options.sampling_frequency);
return 0 == GetSliceRangedNPHash(block_key, trace_options.sampling_frequency);
}
} // namespace

@ -87,7 +87,7 @@ class BloomMath {
// A fast, flexible, and accurate cache-local Bloom implementation with
// SIMD-optimized query performance (currently using AVX2 on Intel). Write
// performance and non-SIMD read are very good, benefiting from fastrange32
// performance and non-SIMD read are very good, benefiting from FastRange32
// used in place of % and single-cycle multiplication on recent processors.
//
// Most other SIMD Bloom implementations sacrifice flexibility and/or
@ -193,7 +193,7 @@ class FastLocalBloomImpl {
static inline void AddHash(uint32_t h1, uint32_t h2, uint32_t len_bytes,
int num_probes, char *data) {
uint32_t bytes_to_cache_line = fastrange32(len_bytes >> 6, h1) << 6;
uint32_t bytes_to_cache_line = FastRange32(len_bytes >> 6, h1) << 6;
AddHashPrepared(h2, num_probes, data + bytes_to_cache_line);
}
@ -210,7 +210,7 @@ class FastLocalBloomImpl {
static inline void PrepareHash(uint32_t h1, uint32_t len_bytes,
const char *data,
uint32_t /*out*/ *byte_offset) {
uint32_t bytes_to_cache_line = fastrange32(len_bytes >> 6, h1) << 6;
uint32_t bytes_to_cache_line = FastRange32(len_bytes >> 6, h1) << 6;
PREFETCH(data + bytes_to_cache_line, 0 /* rw */, 1 /* locality */);
PREFETCH(data + bytes_to_cache_line + 63, 0 /* rw */, 1 /* locality */);
*byte_offset = bytes_to_cache_line;
@ -218,7 +218,7 @@ class FastLocalBloomImpl {
static inline bool HashMayMatch(uint32_t h1, uint32_t h2, uint32_t len_bytes,
int num_probes, const char *data) {
uint32_t bytes_to_cache_line = fastrange32(len_bytes >> 6, h1) << 6;
uint32_t bytes_to_cache_line = FastRange32(len_bytes >> 6, h1) << 6;
return HashMayMatchPrepared(h2, num_probes, data + bytes_to_cache_line);
}

@ -126,7 +126,7 @@ inline void DynamicBloom::MayContain(int num_keys, Slice** keys,
std::array<size_t, MultiGetContext::MAX_BATCH_SIZE> byte_offsets;
for (int i = 0; i < num_keys; ++i) {
hashes[i] = BloomHash(*keys[i]);
size_t a = fastrange32(kLen, hashes[i]);
size_t a = FastRange32(kLen, hashes[i]);
PREFETCH(data_ + a, 0, 3);
byte_offsets[i] = a;
}
@ -142,7 +142,7 @@ inline void DynamicBloom::MayContain(int num_keys, Slice** keys,
#pragma warning(disable : 4189)
#endif
inline void DynamicBloom::Prefetch(uint32_t h32) {
size_t a = fastrange32(kLen, h32);
size_t a = FastRange32(kLen, h32);
PREFETCH(data_ + a, 0, 3);
}
#if defined(_MSC_VER)
@ -171,7 +171,7 @@ inline void DynamicBloom::Prefetch(uint32_t h32) {
// because of false positives.)
inline bool DynamicBloom::MayContainHash(uint32_t h32) const {
size_t a = fastrange32(kLen, h32);
size_t a = FastRange32(kLen, h32);
PREFETCH(data_ + a, 0, 3);
return DoubleProbe(h32, a);
}
@ -195,7 +195,7 @@ inline bool DynamicBloom::DoubleProbe(uint32_t h32, size_t byte_offset) const {
template <typename OrFunc>
inline void DynamicBloom::AddHash(uint32_t h32, const OrFunc& or_func) {
size_t a = fastrange32(kLen, h32);
size_t a = FastRange32(kLen, h32);
PREFETCH(data_ + a, 0, 3);
// Expand/remix with 64-bit golden ratio
uint64_t h = 0x9e3779b97f4a7c13ULL * h32;

@ -0,0 +1,112 @@
// Copyright (c) Facebook, Inc. and its affiliates. 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).
// fastrange/FastRange: A faster alternative to % for mapping a hash value
// to an arbitrary range. See https://github.com/lemire/fastrange
//
// Generally recommended are FastRange32 for mapping results of 32-bit
// hash functions and FastRange64 for mapping results of 64-bit hash
// functions. FastRange is less forgiving than % if the input hashes are
// not well distributed over the full range of the type (32 or 64 bits).
//
// Also included is a templated implementation FastRangeGeneric for use
// in generic algorithms, but not otherwise recommended because of
// potential ambiguity. Unlike with %, it is critical to use the right
// FastRange variant for the output size of your hash function.
#pragma once
#include <cstddef>
#include <cstdint>
#include <type_traits>
#ifdef TEST_UINT128_COMPAT
#undef HAVE_UINT128_EXTENSION
#endif
namespace ROCKSDB_NAMESPACE {
namespace detail {
// Using a class template to support partial specialization
template <typename Hash, typename Range>
struct FastRangeGenericImpl {
// only reach this on no supported specialization
};
template <typename Range>
struct FastRangeGenericImpl<uint32_t, Range> {
static inline Range Fn(uint32_t hash, Range range) {
static_assert(std::is_unsigned<Range>::value, "must be unsigned");
static_assert(sizeof(Range) <= sizeof(uint32_t),
"cannot be larger than hash (32 bits)");
uint64_t product = uint64_t{range} * hash;
return static_cast<Range>(product >> 32);
}
};
template <typename Range>
struct FastRangeGenericImpl<uint64_t, Range> {
static inline Range Fn(uint64_t hash, Range range) {
static_assert(std::is_unsigned<Range>::value, "must be unsigned");
static_assert(sizeof(Range) <= sizeof(uint64_t),
"cannot be larger than hash (64 bits)");
#ifdef HAVE_UINT128_EXTENSION
// Can use compiler's 128-bit type. Trust it to do the right thing.
__uint128_t wide = __uint128_t{range} * hash;
return static_cast<Range>(wide >> 64);
#else
// Fall back: full decomposition.
// NOTE: GCC seems to fully understand this code as 64-bit x 64-bit
// -> 128-bit multiplication and optimize it appropriately
uint64_t range64 = range; // ok to shift by 32, even if Range is 32-bit
uint64_t tmp = uint64_t{range64 & 0xffffFFFF} * uint64_t{hash & 0xffffFFFF};
tmp >>= 32;
tmp += uint64_t{range64 & 0xffffFFFF} * uint64_t{hash >> 32};
// Avoid overflow: first add lower 32 of tmp2, and later upper 32
uint64_t tmp2 = uint64_t{range64 >> 32} * uint64_t{hash & 0xffffFFFF};
tmp += static_cast<uint32_t>(tmp2);
tmp >>= 32;
tmp += (tmp2 >> 32);
tmp += uint64_t{range64 >> 32} * uint64_t{hash >> 32};
return static_cast<Range>(tmp);
#endif
}
};
} // namespace detail
// Now an omnibus templated function (yay parameter inference).
//
// NOTICE:
// This templated version is not recommended for typical use because
// of the potential to mix a 64-bit FastRange with a 32-bit bit hash,
// most likely because you put your 32-bit hash in an "unsigned long"
// which is 64 bits on some platforms. That doesn't really matter for
// an operation like %, but 64-bit FastRange gives extremely bad results,
// mostly zero, on 32-bit hash values. And because good hashing is not
// generally required for correctness, this kind of mistake could go
// unnoticed with just unit tests. Plus it could vary by platform.
template <typename Hash, typename Range>
inline Range FastRangeGeneric(Hash hash, Range range) {
return detail::FastRangeGenericImpl<Hash, Range>::Fn(hash, range);
}
// The most popular / convenient / recommended variants:
// Map a quality 64-bit hash value down to an arbitrary size_t range.
// (size_t is standard for mapping to things in memory.)
inline size_t FastRange64(uint64_t hash, size_t range) {
return FastRangeGeneric(hash, range);
}
// Map a quality 32-bit hash value down to an arbitrary uint32_t range.
inline uint32_t FastRange32(uint32_t hash, uint32_t range) {
return FastRangeGeneric(hash, range);
}
} // namespace ROCKSDB_NAMESPACE

@ -124,7 +124,7 @@ using ROCKSDB_NAMESPACE::BloomHash;
using ROCKSDB_NAMESPACE::BuiltinFilterBitsBuilder;
using ROCKSDB_NAMESPACE::CachableEntry;
using ROCKSDB_NAMESPACE::EncodeFixed32;
using ROCKSDB_NAMESPACE::fastrange32;
using ROCKSDB_NAMESPACE::FastRange32;
using ROCKSDB_NAMESPACE::FilterBitsReader;
using ROCKSDB_NAMESPACE::FilterBuildingContext;
using ROCKSDB_NAMESPACE::FullFilterBlockReader;
@ -161,7 +161,7 @@ struct KeyMaker {
if (FLAGS_vary_key_size_log2_interval < 30) {
// To get range [avg_size - 2, avg_size + 2]
// use range [smallest_size, smallest_size + 4]
len += fastrange32(
len += FastRange32(
(val_num >> FLAGS_vary_key_size_log2_interval) * 1234567891, 5);
}
char * data = buf_.get() + start;
@ -365,7 +365,7 @@ void FilterBench::Go() {
total_keys_added < max_total_keys) {
uint32_t filter_id = random_.Next();
uint32_t keys_to_add = FLAGS_average_keys_per_filter +
fastrange32(random_.Next(), variance_range) -
FastRange32(random_.Next(), variance_range) -
variance_offset;
if (max_total_keys - total_keys_added < keys_to_add) {
keys_to_add = static_cast<uint32_t>(max_total_keys - total_keys_added);

@ -18,10 +18,12 @@
// hash inputs.
#pragma once
#include <stddef.h>
#include <stdint.h>
#include <cstddef>
#include <cstdint>
#include "rocksdb/slice.h"
#include "util/fastrange.h"
namespace ROCKSDB_NAMESPACE {
@ -64,6 +66,10 @@ inline uint64_t GetSliceNPHash64(const Slice& s) {
return NPHash64(s.data(), s.size());
}
inline size_t GetSliceRangedNPHash(const Slice& s, size_t range) {
return FastRange64(NPHash64(s.data(), s.size()), range);
}
// TODO: consider rename to GetSliceHash32
inline uint32_t GetSliceHash(const Slice& s) {
return Hash(s.data(), s.size(), 397);
@ -81,44 +87,4 @@ struct SliceHasher {
uint32_t operator()(const Slice& s) const { return GetSliceHash(s); }
};
// An alternative to % for mapping a hash value to an arbitrary range. See
// https://github.com/lemire/fastrange
inline uint32_t fastrange32(uint32_t hash, uint32_t range) {
uint64_t product = uint64_t{range} * hash;
return static_cast<uint32_t>(product >> 32);
}
#ifdef TEST_UINT128_COMPAT
#undef HAVE_UINT128_EXTENSION
#endif
// An alternative to % for mapping a 64-bit hash value to an arbitrary range
// that fits in size_t. See https://github.com/lemire/fastrange
// We find size_t more convenient than uint64_t for the range, with side
// benefit of better optimization on 32-bit platforms.
inline size_t fastrange64(uint64_t hash, size_t range) {
#ifdef HAVE_UINT128_EXTENSION
// Can use compiler's 128-bit type. Trust it to do the right thing.
__uint128_t wide = __uint128_t{range} * hash;
return static_cast<size_t>(wide >> 64);
#else
// Fall back: full decomposition.
// NOTE: GCC seems to fully understand this code as 64-bit x {32 or 64}-bit
// -> {96 or 128}-bit multiplication and optimize it down to a single
// wide-result multiplication (64-bit platform) or two wide-result
// multiplications (32-bit platforms, where range64 >> 32 is zero).
uint64_t range64 = range; // ok to shift by 32, even if size_t is 32-bit
uint64_t tmp = uint64_t{range64 & 0xffffFFFF} * uint64_t{hash & 0xffffFFFF};
tmp >>= 32;
tmp += uint64_t{range64 & 0xffffFFFF} * uint64_t{hash >> 32};
// Avoid overflow: first add lower 32 of tmp2, and later upper 32
uint64_t tmp2 = uint64_t{range64 >> 32} * uint64_t{hash & 0xffffFFFF};
tmp += static_cast<uint32_t>(tmp2);
tmp >>= 32;
tmp += (tmp2 >> 32);
tmp += uint64_t{range64 >> 32} * uint64_t{hash >> 32};
return static_cast<size_t>(tmp);
#endif
}
} // namespace ROCKSDB_NAMESPACE

@ -267,109 +267,128 @@ TEST(HashTest, Hash64LargeValueSchema) {
"eMFlxCIYUpTCsal2qsmnGOWa8WCcefrohMjDj1fjzSvSaQwlpyR1GZHF2uPOoQagiCpHpm");
}
TEST(Fastrange32Test, Values) {
using ROCKSDB_NAMESPACE::fastrange32;
TEST(FastRange32Test, Values) {
using ROCKSDB_NAMESPACE::FastRange32;
// Zero range
EXPECT_EQ(fastrange32(0, 0), 0U);
EXPECT_EQ(fastrange32(123, 0), 0U);
EXPECT_EQ(fastrange32(0xffffffff, 0), 0U);
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);
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);
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);
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);
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);
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_NAMESPACE::fastrange64;
TEST(FastRange64Test, Values) {
using ROCKSDB_NAMESPACE::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);
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);
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);
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);
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);
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(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(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),
EXPECT_EQ(FastRange64(0xffffFFFFffffFFFF, 0xffffFFFFffffFFFF),
0xffffFFFFffffFFFEU);
#endif
}
TEST(FastRangeGenericTest, Values) {
using ROCKSDB_NAMESPACE::FastRangeGeneric;
// Generic (including big and small)
// Note that FastRangeGeneric is also tested indirectly above via
// FastRange32 and FastRange64.
EXPECT_EQ(
FastRangeGeneric(uint64_t{0x8000000000000000}, uint64_t{420000000002}),
uint64_t{210000000001});
EXPECT_EQ(FastRangeGeneric(uint64_t{0x8000000000000000}, uint16_t{12468}),
uint16_t{6234});
EXPECT_EQ(FastRangeGeneric(uint32_t{0x80000000}, uint16_t{12468}),
uint16_t{6234});
// Not recommended for typical use because for example this could fail on
// some platforms and pass on others:
//EXPECT_EQ(FastRangeGeneric(static_cast<unsigned long>(0x80000000),
// uint16_t{12468}),
// uint16_t{6234});
}
// for inspection of disassembly
uint32_t fastrange32(uint32_t hash, uint32_t range) {
return ROCKSDB_NAMESPACE::fastrange32(hash, range);
uint32_t FastRange32(uint32_t hash, uint32_t range) {
return ROCKSDB_NAMESPACE::FastRange32(hash, range);
}
// for inspection of disassembly
size_t fastrange64(uint64_t hash, size_t range) {
return ROCKSDB_NAMESPACE::fastrange64(hash, range);
size_t FastRange64(uint64_t hash, size_t range) {
return ROCKSDB_NAMESPACE::FastRange64(hash, range);
}
// Tests for math.h / math128.h (not worth a separate test binary)

@ -6,11 +6,13 @@
#pragma once
#include <assert.h>
#include <stdint.h>
#ifdef _MSC_VER
#include <intrin.h>
#endif
#include <cstdint>
#include <type_traits>
namespace ROCKSDB_NAMESPACE {
// Fast implementation of floor(log2(v)). Undefined for 0 or negative

@ -107,7 +107,7 @@ Status OptimisticTransaction::CommitWithParallelValidate() {
assert(key_it != nullptr);
while (key_it->HasNext()) {
const std::string& key = key_it->Next();
lk_idxes.insert(fastrange64(GetSliceNPHash64(key), space));
lk_idxes.insert(FastRange64(GetSliceNPHash64(key), space));
}
}
// NOTE: in a single txn, all bucket-locks are taken in ascending order.

@ -173,7 +173,7 @@ TransactionLockMgr::~TransactionLockMgr() {}
size_t LockMap::GetStripe(const std::string& key) const {
assert(num_stripes_ > 0);
return fastrange64(GetSliceNPHash64(key), num_stripes_);
return FastRange64(GetSliceNPHash64(key), num_stripes_);
}
void TransactionLockMgr::AddColumnFamily(uint32_t column_family_id) {

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