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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/container/internal/raw_hash_set.h"
#include <algorithm>
#include <atomic>
#include <cmath>
#include <cstddef>
#include <cstdint>
#include <deque>
#include <functional>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <ostream>
#include <random>
#include <string>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/attributes.h"
#include "absl/base/config.h"
#include "absl/base/internal/cycleclock.h"
#include "absl/base/prefetch.h"
#include "absl/container/flat_hash_map.h"
#include "absl/container/flat_hash_set.h"
#include "absl/container/internal/container_memory.h"
#include "absl/container/internal/hash_function_defaults.h"
#include "absl/container/internal/hash_policy_testing.h"
#include "absl/container/internal/hashtable_debug.h"
#include "absl/container/internal/test_allocator.h"
#include "absl/log/log.h"
#include "absl/strings/string_view.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
struct RawHashSetTestOnlyAccess {
template <typename C>
static auto GetSlots(const C& c) -> decltype(c.slot_array()) {
return c.slot_array();
}
template <typename C>
static size_t CountTombstones(const C& c) {
return c.common().TombstonesCount();
}
};
namespace {
using ::testing::ElementsAre;
using ::testing::Eq;
using ::testing::Ge;
using ::testing::Lt;
using ::testing::Pair;
using ::testing::UnorderedElementsAre;
// Convenience function to static cast to ctrl_t.
ctrl_t CtrlT(int i) { return static_cast<ctrl_t>(i); }
TEST(Util, NormalizeCapacity) {
EXPECT_EQ(1, NormalizeCapacity(0));
EXPECT_EQ(1, NormalizeCapacity(1));
EXPECT_EQ(3, NormalizeCapacity(2));
EXPECT_EQ(3, NormalizeCapacity(3));
EXPECT_EQ(7, NormalizeCapacity(4));
EXPECT_EQ(7, NormalizeCapacity(7));
EXPECT_EQ(15, NormalizeCapacity(8));
EXPECT_EQ(15, NormalizeCapacity(15));
EXPECT_EQ(15 * 2 + 1, NormalizeCapacity(15 + 1));
EXPECT_EQ(15 * 2 + 1, NormalizeCapacity(15 + 2));
}
TEST(Util, GrowthAndCapacity) {
// Verify that GrowthToCapacity gives the minimum capacity that has enough
// growth.
for (size_t growth = 0; growth < 10000; ++growth) {
SCOPED_TRACE(growth);
size_t capacity = NormalizeCapacity(GrowthToLowerboundCapacity(growth));
// The capacity is large enough for `growth`.
EXPECT_THAT(CapacityToGrowth(capacity), Ge(growth));
// For (capacity+1) < kWidth, growth should equal capacity.
if (capacity + 1 < Group::kWidth) {
EXPECT_THAT(CapacityToGrowth(capacity), Eq(capacity));
} else {
EXPECT_THAT(CapacityToGrowth(capacity), Lt(capacity));
}
if (growth != 0 && capacity > 1) {
// There is no smaller capacity that works.
EXPECT_THAT(CapacityToGrowth(capacity / 2), Lt(growth));
}
}
for (size_t capacity = Group::kWidth - 1; capacity < 10000;
capacity = 2 * capacity + 1) {
SCOPED_TRACE(capacity);
size_t growth = CapacityToGrowth(capacity);
EXPECT_THAT(growth, Lt(capacity));
EXPECT_LE(GrowthToLowerboundCapacity(growth), capacity);
EXPECT_EQ(NormalizeCapacity(GrowthToLowerboundCapacity(growth)), capacity);
}
}
TEST(Util, probe_seq) {
probe_seq<16> seq(0, 127);
auto gen = [&]() {
size_t res = seq.offset();
seq.next();
return res;
};
std::vector<size_t> offsets(8);
std::generate_n(offsets.begin(), 8, gen);
EXPECT_THAT(offsets, ElementsAre(0, 16, 48, 96, 32, 112, 80, 64));
seq = probe_seq<16>(128, 127);
std::generate_n(offsets.begin(), 8, gen);
EXPECT_THAT(offsets, ElementsAre(0, 16, 48, 96, 32, 112, 80, 64));
}
TEST(BitMask, Smoke) {
EXPECT_FALSE((BitMask<uint8_t, 8>(0)));
EXPECT_TRUE((BitMask<uint8_t, 8>(5)));
EXPECT_THAT((BitMask<uint8_t, 8>(0)), ElementsAre());
EXPECT_THAT((BitMask<uint8_t, 8>(0x1)), ElementsAre(0));
EXPECT_THAT((BitMask<uint8_t, 8>(0x2)), ElementsAre(1));
EXPECT_THAT((BitMask<uint8_t, 8>(0x3)), ElementsAre(0, 1));
EXPECT_THAT((BitMask<uint8_t, 8>(0x4)), ElementsAre(2));
EXPECT_THAT((BitMask<uint8_t, 8>(0x5)), ElementsAre(0, 2));
EXPECT_THAT((BitMask<uint8_t, 8>(0x55)), ElementsAre(0, 2, 4, 6));
EXPECT_THAT((BitMask<uint8_t, 8>(0xAA)), ElementsAre(1, 3, 5, 7));
}
TEST(BitMask, WithShift) {
// See the non-SSE version of Group for details on what this math is for.
uint64_t ctrl = 0x1716151413121110;
uint64_t hash = 0x12;
constexpr uint64_t msbs = 0x8080808080808080ULL;
constexpr uint64_t lsbs = 0x0101010101010101ULL;
auto x = ctrl ^ (lsbs * hash);
uint64_t mask = (x - lsbs) & ~x & msbs;
EXPECT_EQ(0x0000000080800000, mask);
BitMask<uint64_t, 8, 3> b(mask);
EXPECT_EQ(*b, 2);
}
TEST(BitMask, LeadingTrailing) {
EXPECT_EQ((BitMask<uint32_t, 16>(0x00001a40).LeadingZeros()), 3);
EXPECT_EQ((BitMask<uint32_t, 16>(0x00001a40).TrailingZeros()), 6);
EXPECT_EQ((BitMask<uint32_t, 16>(0x00000001).LeadingZeros()), 15);
EXPECT_EQ((BitMask<uint32_t, 16>(0x00000001).TrailingZeros()), 0);
EXPECT_EQ((BitMask<uint32_t, 16>(0x00008000).LeadingZeros()), 0);
EXPECT_EQ((BitMask<uint32_t, 16>(0x00008000).TrailingZeros()), 15);
EXPECT_EQ((BitMask<uint64_t, 8, 3>(0x0000008080808000).LeadingZeros()), 3);
EXPECT_EQ((BitMask<uint64_t, 8, 3>(0x0000008080808000).TrailingZeros()), 1);
EXPECT_EQ((BitMask<uint64_t, 8, 3>(0x0000000000000080).LeadingZeros()), 7);
EXPECT_EQ((BitMask<uint64_t, 8, 3>(0x0000000000000080).TrailingZeros()), 0);
EXPECT_EQ((BitMask<uint64_t, 8, 3>(0x8000000000000000).LeadingZeros()), 0);
EXPECT_EQ((BitMask<uint64_t, 8, 3>(0x8000000000000000).TrailingZeros()), 7);
}
TEST(Group, EmptyGroup) {
for (h2_t h = 0; h != 128; ++h) EXPECT_FALSE(Group{EmptyGroup()}.Match(h));
}
TEST(Group, Match) {
if (Group::kWidth == 16) {
ctrl_t group[] = {ctrl_t::kEmpty, CtrlT(1), ctrl_t::kDeleted, CtrlT(3),
ctrl_t::kEmpty, CtrlT(5), ctrl_t::kSentinel, CtrlT(7),
CtrlT(7), CtrlT(5), CtrlT(3), CtrlT(1),
CtrlT(1), CtrlT(1), CtrlT(1), CtrlT(1)};
EXPECT_THAT(Group{group}.Match(0), ElementsAre());
EXPECT_THAT(Group{group}.Match(1), ElementsAre(1, 11, 12, 13, 14, 15));
EXPECT_THAT(Group{group}.Match(3), ElementsAre(3, 10));
EXPECT_THAT(Group{group}.Match(5), ElementsAre(5, 9));
EXPECT_THAT(Group{group}.Match(7), ElementsAre(7, 8));
} else if (Group::kWidth == 8) {
ctrl_t group[] = {ctrl_t::kEmpty, CtrlT(1), CtrlT(2),
ctrl_t::kDeleted, CtrlT(2), CtrlT(1),
ctrl_t::kSentinel, CtrlT(1)};
EXPECT_THAT(Group{group}.Match(0), ElementsAre());
EXPECT_THAT(Group{group}.Match(1), ElementsAre(1, 5, 7));
EXPECT_THAT(Group{group}.Match(2), ElementsAre(2, 4));
} else {
FAIL() << "No test coverage for Group::kWidth==" << Group::kWidth;
}
}
TEST(Group, MaskEmpty) {
if (Group::kWidth == 16) {
ctrl_t group[] = {ctrl_t::kEmpty, CtrlT(1), ctrl_t::kDeleted, CtrlT(3),
ctrl_t::kEmpty, CtrlT(5), ctrl_t::kSentinel, CtrlT(7),
CtrlT(7), CtrlT(5), CtrlT(3), CtrlT(1),
CtrlT(1), CtrlT(1), CtrlT(1), CtrlT(1)};
EXPECT_THAT(Group{group}.MaskEmpty().LowestBitSet(), 0);
EXPECT_THAT(Group{group}.MaskEmpty().HighestBitSet(), 4);
} else if (Group::kWidth == 8) {
ctrl_t group[] = {ctrl_t::kEmpty, CtrlT(1), CtrlT(2),
ctrl_t::kDeleted, CtrlT(2), CtrlT(1),
ctrl_t::kSentinel, CtrlT(1)};
EXPECT_THAT(Group{group}.MaskEmpty().LowestBitSet(), 0);
EXPECT_THAT(Group{group}.MaskEmpty().HighestBitSet(), 0);
} else {
FAIL() << "No test coverage for Group::kWidth==" << Group::kWidth;
}
}
TEST(Group, MaskEmptyOrDeleted) {
if (Group::kWidth == 16) {
ctrl_t group[] = {ctrl_t::kEmpty, CtrlT(1), ctrl_t::kEmpty, CtrlT(3),
ctrl_t::kDeleted, CtrlT(5), ctrl_t::kSentinel, CtrlT(7),
CtrlT(7), CtrlT(5), CtrlT(3), CtrlT(1),
CtrlT(1), CtrlT(1), CtrlT(1), CtrlT(1)};
EXPECT_THAT(Group{group}.MaskEmptyOrDeleted().LowestBitSet(), 0);
EXPECT_THAT(Group{group}.MaskEmptyOrDeleted().HighestBitSet(), 4);
} else if (Group::kWidth == 8) {
ctrl_t group[] = {ctrl_t::kEmpty, CtrlT(1), CtrlT(2),
ctrl_t::kDeleted, CtrlT(2), CtrlT(1),
ctrl_t::kSentinel, CtrlT(1)};
EXPECT_THAT(Group{group}.MaskEmptyOrDeleted().LowestBitSet(), 0);
EXPECT_THAT(Group{group}.MaskEmptyOrDeleted().HighestBitSet(), 3);
} else {
FAIL() << "No test coverage for Group::kWidth==" << Group::kWidth;
}
}
TEST(Batch, DropDeletes) {
constexpr size_t kCapacity = 63;
constexpr size_t kGroupWidth = container_internal::Group::kWidth;
std::vector<ctrl_t> ctrl(kCapacity + 1 + kGroupWidth);
ctrl[kCapacity] = ctrl_t::kSentinel;
std::vector<ctrl_t> pattern = {
ctrl_t::kEmpty, CtrlT(2), ctrl_t::kDeleted, CtrlT(2),
ctrl_t::kEmpty, CtrlT(1), ctrl_t::kDeleted};
for (size_t i = 0; i != kCapacity; ++i) {
ctrl[i] = pattern[i % pattern.size()];
if (i < kGroupWidth - 1)
ctrl[i + kCapacity + 1] = pattern[i % pattern.size()];
}
ConvertDeletedToEmptyAndFullToDeleted(ctrl.data(), kCapacity);
ASSERT_EQ(ctrl[kCapacity], ctrl_t::kSentinel);
for (size_t i = 0; i < kCapacity + kGroupWidth; ++i) {
ctrl_t expected = pattern[i % (kCapacity + 1) % pattern.size()];
if (i == kCapacity) expected = ctrl_t::kSentinel;
if (expected == ctrl_t::kDeleted) expected = ctrl_t::kEmpty;
if (IsFull(expected)) expected = ctrl_t::kDeleted;
EXPECT_EQ(ctrl[i], expected)
<< i << " " << static_cast<int>(pattern[i % pattern.size()]);
}
}
TEST(Group, CountLeadingEmptyOrDeleted) {
const std::vector<ctrl_t> empty_examples = {ctrl_t::kEmpty, ctrl_t::kDeleted};
const std::vector<ctrl_t> full_examples = {
CtrlT(0), CtrlT(1), CtrlT(2), CtrlT(3),
CtrlT(5), CtrlT(9), CtrlT(127), ctrl_t::kSentinel};
for (ctrl_t empty : empty_examples) {
std::vector<ctrl_t> e(Group::kWidth, empty);
EXPECT_EQ(Group::kWidth, Group{e.data()}.CountLeadingEmptyOrDeleted());
for (ctrl_t full : full_examples) {
for (size_t i = 0; i != Group::kWidth; ++i) {
std::vector<ctrl_t> f(Group::kWidth, empty);
f[i] = full;
EXPECT_EQ(i, Group{f.data()}.CountLeadingEmptyOrDeleted());
}
std::vector<ctrl_t> f(Group::kWidth, empty);
f[Group::kWidth * 2 / 3] = full;
f[Group::kWidth / 2] = full;
EXPECT_EQ(
Group::kWidth / 2, Group{f.data()}.CountLeadingEmptyOrDeleted());
}
}
}
template <class T>
struct ValuePolicy {
using slot_type = T;
using key_type = T;
using init_type = T;
template <class Allocator, class... Args>
static void construct(Allocator* alloc, slot_type* slot, Args&&... args) {
absl::allocator_traits<Allocator>::construct(*alloc, slot,
std::forward<Args>(args)...);
}
template <class Allocator>
static void destroy(Allocator* alloc, slot_type* slot) {
absl::allocator_traits<Allocator>::destroy(*alloc, slot);
}
template <class Allocator>
static void transfer(Allocator* alloc, slot_type* new_slot,
slot_type* old_slot) {
construct(alloc, new_slot, std::move(*old_slot));
destroy(alloc, old_slot);
}
static T& element(slot_type* slot) { return *slot; }
template <class F, class... Args>
static decltype(absl::container_internal::DecomposeValue(
std::declval<F>(), std::declval<Args>()...))
apply(F&& f, Args&&... args) {
return absl::container_internal::DecomposeValue(
std::forward<F>(f), std::forward<Args>(args)...);
}
};
using IntPolicy = ValuePolicy<int64_t>;
using Uint8Policy = ValuePolicy<uint8_t>;
class StringPolicy {
template <class F, class K, class V,
class = typename std::enable_if<
std::is_convertible<const K&, absl::string_view>::value>::type>
decltype(std::declval<F>()(
std::declval<const absl::string_view&>(), std::piecewise_construct,
std::declval<std::tuple<K>>(),
std::declval<V>())) static apply_impl(F&& f,
std::pair<std::tuple<K>, V> p) {
const absl::string_view& key = std::get<0>(p.first);
return std::forward<F>(f)(key, std::piecewise_construct, std::move(p.first),
std::move(p.second));
}
public:
struct slot_type {
struct ctor {};
template <class... Ts>
explicit slot_type(ctor, Ts&&... ts) : pair(std::forward<Ts>(ts)...) {}
std::pair<std::string, std::string> pair;
};
using key_type = std::string;
using init_type = std::pair<std::string, std::string>;
template <class allocator_type, class... Args>
static void construct(allocator_type* alloc, slot_type* slot, Args... args) {
std::allocator_traits<allocator_type>::construct(
*alloc, slot, typename slot_type::ctor(), std::forward<Args>(args)...);
}
template <class allocator_type>
static void destroy(allocator_type* alloc, slot_type* slot) {
std::allocator_traits<allocator_type>::destroy(*alloc, slot);
}
template <class allocator_type>
static void transfer(allocator_type* alloc, slot_type* new_slot,
slot_type* old_slot) {
construct(alloc, new_slot, std::move(old_slot->pair));
destroy(alloc, old_slot);
}
static std::pair<std::string, std::string>& element(slot_type* slot) {
return slot->pair;
}
template <class F, class... Args>
static auto apply(F&& f, Args&&... args)
-> decltype(apply_impl(std::forward<F>(f),
PairArgs(std::forward<Args>(args)...))) {
return apply_impl(std::forward<F>(f),
PairArgs(std::forward<Args>(args)...));
}
};
struct StringHash : absl::Hash<absl::string_view> {
using is_transparent = void;
};
struct StringEq : std::equal_to<absl::string_view> {
using is_transparent = void;
};
struct StringTable
: raw_hash_set<StringPolicy, StringHash, StringEq, std::allocator<int>> {
using Base = typename StringTable::raw_hash_set;
StringTable() = default;
using Base::Base;
};
struct IntTable
: raw_hash_set<IntPolicy, container_internal::hash_default_hash<int64_t>,
std::equal_to<int64_t>, std::allocator<int64_t>> {
using Base = typename IntTable::raw_hash_set;
using Base::Base;
};
struct Uint8Table
: raw_hash_set<Uint8Policy, container_internal::hash_default_hash<uint8_t>,
std::equal_to<uint8_t>, std::allocator<uint8_t>> {
using Base = typename Uint8Table::raw_hash_set;
using Base::Base;
};
template <typename T>
struct CustomAlloc : std::allocator<T> {
CustomAlloc() = default;
template <typename U>
explicit CustomAlloc(const CustomAlloc<U>& /*other*/) {}
template<class U> struct rebind {
using other = CustomAlloc<U>;
};
};
struct CustomAllocIntTable
: raw_hash_set<IntPolicy, container_internal::hash_default_hash<int64_t>,
std::equal_to<int64_t>, CustomAlloc<int64_t>> {
using Base = typename CustomAllocIntTable::raw_hash_set;
using Base::Base;
};
struct MinimumAlignmentUint8Table
: raw_hash_set<Uint8Policy, container_internal::hash_default_hash<uint8_t>,
std::equal_to<uint8_t>, MinimumAlignmentAlloc<uint8_t>> {
using Base = typename MinimumAlignmentUint8Table::raw_hash_set;
using Base::Base;
};
// Allows for freezing the allocator to expect no further allocations.
template <typename T>
struct FreezableAlloc : std::allocator<T> {
explicit FreezableAlloc(bool* f) : frozen(f) {}
template <typename U>
explicit FreezableAlloc(const FreezableAlloc<U>& other)
: frozen(other.frozen) {}
template <class U>
struct rebind {
using other = FreezableAlloc<U>;
};
T* allocate(size_t n) {
EXPECT_FALSE(*frozen);
return std::allocator<T>::allocate(n);
}
bool* frozen;
};
struct BadFastHash {
template <class T>
size_t operator()(const T&) const {
return 0;
}
};
struct BadHashFreezableIntTable
: raw_hash_set<IntPolicy, BadFastHash, std::equal_to<int64_t>,
FreezableAlloc<int64_t>> {
using Base = typename BadHashFreezableIntTable::raw_hash_set;
using Base::Base;
};
struct BadTable : raw_hash_set<IntPolicy, BadFastHash, std::equal_to<int>,
std::allocator<int>> {
using Base = typename BadTable::raw_hash_set;
BadTable() = default;
using Base::Base;
};
TEST(Table, EmptyFunctorOptimization) {
static_assert(std::is_empty<std::equal_to<absl::string_view>>::value, "");
static_assert(std::is_empty<std::allocator<int>>::value, "");
struct MockTable {
void* ctrl;
void* slots;
size_t size;
size_t capacity;
};
struct StatelessHash {
size_t operator()(absl::string_view) const { return 0; }
};
struct StatefulHash : StatelessHash {
size_t dummy;
};
struct GenerationData {
size_t reserved_growth;
size_t reservation_size;
GenerationType* generation;
};
// Ignore unreachable-code warning. Compiler thinks one branch of each ternary
// conditional is unreachable.
#if defined(__clang__)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunreachable-code"
#endif
constexpr size_t mock_size = sizeof(MockTable);
constexpr size_t generation_size =
SwisstableGenerationsEnabled() ? sizeof(GenerationData) : 0;
#if defined(__clang__)
#pragma clang diagnostic pop
#endif
EXPECT_EQ(
mock_size + generation_size,
sizeof(
raw_hash_set<StringPolicy, StatelessHash,
std::equal_to<absl::string_view>, std::allocator<int>>));
EXPECT_EQ(
mock_size + sizeof(StatefulHash) + generation_size,
sizeof(
raw_hash_set<StringPolicy, StatefulHash,
std::equal_to<absl::string_view>, std::allocator<int>>));
}
TEST(Table, Empty) {
IntTable t;
EXPECT_EQ(0, t.size());
EXPECT_TRUE(t.empty());
}
TEST(Table, LookupEmpty) {
IntTable t;
auto it = t.find(0);
EXPECT_TRUE(it == t.end());
}
TEST(Table, Insert1) {
IntTable t;
EXPECT_TRUE(t.find(0) == t.end());
auto res = t.emplace(0);
EXPECT_TRUE(res.second);
EXPECT_THAT(*res.first, 0);
EXPECT_EQ(1, t.size());
EXPECT_THAT(*t.find(0), 0);
}
TEST(Table, Insert2) {
IntTable t;
EXPECT_TRUE(t.find(0) == t.end());
auto res = t.emplace(0);
EXPECT_TRUE(res.second);
EXPECT_THAT(*res.first, 0);
EXPECT_EQ(1, t.size());
EXPECT_TRUE(t.find(1) == t.end());
res = t.emplace(1);
EXPECT_TRUE(res.second);
EXPECT_THAT(*res.first, 1);
EXPECT_EQ(2, t.size());
EXPECT_THAT(*t.find(0), 0);
EXPECT_THAT(*t.find(1), 1);
}
TEST(Table, InsertCollision) {
BadTable t;
EXPECT_TRUE(t.find(1) == t.end());
auto res = t.emplace(1);
EXPECT_TRUE(res.second);
EXPECT_THAT(*res.first, 1);
EXPECT_EQ(1, t.size());
EXPECT_TRUE(t.find(2) == t.end());
res = t.emplace(2);
EXPECT_THAT(*res.first, 2);
EXPECT_TRUE(res.second);
EXPECT_EQ(2, t.size());
EXPECT_THAT(*t.find(1), 1);
EXPECT_THAT(*t.find(2), 2);
}
// Test that we do not add existent element in case we need to search through
// many groups with deleted elements
TEST(Table, InsertCollisionAndFindAfterDelete) {
BadTable t; // all elements go to the same group.
// Have at least 2 groups with Group::kWidth collisions
// plus some extra collisions in the last group.
constexpr size_t kNumInserts = Group::kWidth * 2 + 5;
for (size_t i = 0; i < kNumInserts; ++i) {
auto res = t.emplace(i);
EXPECT_TRUE(res.second);
EXPECT_THAT(*res.first, i);
EXPECT_EQ(i + 1, t.size());
}
// Remove elements one by one and check
// that we still can find all other elements.
for (size_t i = 0; i < kNumInserts; ++i) {
EXPECT_EQ(1, t.erase(i)) << i;
for (size_t j = i + 1; j < kNumInserts; ++j) {
EXPECT_THAT(*t.find(j), j);
auto res = t.emplace(j);
EXPECT_FALSE(res.second) << i << " " << j;
EXPECT_THAT(*res.first, j);
EXPECT_EQ(kNumInserts - i - 1, t.size());
}
}
EXPECT_TRUE(t.empty());
}
TEST(Table, InsertWithinCapacity) {
IntTable t;
t.reserve(10);
const size_t original_capacity = t.capacity();
const auto addr = [&](int i) {
return reinterpret_cast<uintptr_t>(&*t.find(i));
};
// Inserting an element does not change capacity.
t.insert(0);
EXPECT_THAT(t.capacity(), original_capacity);
const uintptr_t original_addr_0 = addr(0);
// Inserting another element does not rehash.
t.insert(1);
EXPECT_THAT(t.capacity(), original_capacity);
EXPECT_THAT(addr(0), original_addr_0);
// Inserting lots of duplicate elements does not rehash.
for (int i = 0; i < 100; ++i) {
t.insert(i % 10);
}
EXPECT_THAT(t.capacity(), original_capacity);
EXPECT_THAT(addr(0), original_addr_0);
// Inserting a range of duplicate elements does not rehash.
std::vector<int> dup_range;
for (int i = 0; i < 100; ++i) {
dup_range.push_back(i % 10);
}
t.insert(dup_range.begin(), dup_range.end());
EXPECT_THAT(t.capacity(), original_capacity);
EXPECT_THAT(addr(0), original_addr_0);
}
TEST(Table, LazyEmplace) {
StringTable t;
bool called = false;
auto it = t.lazy_emplace("abc", [&](const StringTable::constructor& f) {
called = true;
f("abc", "ABC");
});
EXPECT_TRUE(called);
EXPECT_THAT(*it, Pair("abc", "ABC"));
called = false;
it = t.lazy_emplace("abc", [&](const StringTable::constructor& f) {
called = true;
f("abc", "DEF");
});
EXPECT_FALSE(called);
EXPECT_THAT(*it, Pair("abc", "ABC"));
}
TEST(Table, ContainsEmpty) {
IntTable t;
EXPECT_FALSE(t.contains(0));
}
TEST(Table, Contains1) {
IntTable t;
EXPECT_TRUE(t.insert(0).second);
EXPECT_TRUE(t.contains(0));
EXPECT_FALSE(t.contains(1));
EXPECT_EQ(1, t.erase(0));
EXPECT_FALSE(t.contains(0));
}
TEST(Table, Contains2) {
IntTable t;
EXPECT_TRUE(t.insert(0).second);
EXPECT_TRUE(t.contains(0));
EXPECT_FALSE(t.contains(1));
t.clear();
EXPECT_FALSE(t.contains(0));
}
int decompose_constructed;
int decompose_copy_constructed;
int decompose_copy_assigned;
int decompose_move_constructed;
int decompose_move_assigned;
struct DecomposeType {
DecomposeType(int i = 0) : i(i) { // NOLINT
++decompose_constructed;
}
explicit DecomposeType(const char* d) : DecomposeType(*d) {}
DecomposeType(const DecomposeType& other) : i(other.i) {
++decompose_copy_constructed;
}
DecomposeType& operator=(const DecomposeType& other) {
++decompose_copy_assigned;
i = other.i;
return *this;
}
DecomposeType(DecomposeType&& other) : i(other.i) {
++decompose_move_constructed;
}
DecomposeType& operator=(DecomposeType&& other) {
++decompose_move_assigned;
i = other.i;
return *this;
}
int i;
};
struct DecomposeHash {
using is_transparent = void;
size_t operator()(const DecomposeType& a) const { return a.i; }
size_t operator()(int a) const { return a; }
size_t operator()(const char* a) const { return *a; }
};
struct DecomposeEq {
using is_transparent = void;
bool operator()(const DecomposeType& a, const DecomposeType& b) const {
return a.i == b.i;
}
bool operator()(const DecomposeType& a, int b) const { return a.i == b; }
bool operator()(const DecomposeType& a, const char* b) const {
return a.i == *b;
}
};
struct DecomposePolicy {
using slot_type = DecomposeType;
using key_type = DecomposeType;
using init_type = DecomposeType;
template <typename T>
static void construct(void*, DecomposeType* slot, T&& v) {
::new (slot) DecomposeType(std::forward<T>(v));
}
static void destroy(void*, DecomposeType* slot) { slot->~DecomposeType(); }
static DecomposeType& element(slot_type* slot) { return *slot; }
template <class F, class T>
static auto apply(F&& f, const T& x) -> decltype(std::forward<F>(f)(x, x)) {
return std::forward<F>(f)(x, x);
}
};
template <typename Hash, typename Eq>
void TestDecompose(bool construct_three) {
DecomposeType elem{0};
const int one = 1;
const char* three_p = "3";
const auto& three = three_p;
const int elem_vector_count = 256;
std::vector<DecomposeType> elem_vector(elem_vector_count, DecomposeType{0});
std::iota(elem_vector.begin(), elem_vector.end(), 0);
using DecomposeSet =
raw_hash_set<DecomposePolicy, Hash, Eq, std::allocator<int>>;
DecomposeSet set1;
decompose_constructed = 0;
int expected_constructed = 0;
EXPECT_EQ(expected_constructed, decompose_constructed);
set1.insert(elem);
EXPECT_EQ(expected_constructed, decompose_constructed);
set1.insert(1);
EXPECT_EQ(++expected_constructed, decompose_constructed);
set1.emplace("3");
EXPECT_EQ(++expected_constructed, decompose_constructed);
EXPECT_EQ(expected_constructed, decompose_constructed);
{ // insert(T&&)
set1.insert(1);
EXPECT_EQ(expected_constructed, decompose_constructed);
}
{ // insert(const T&)
set1.insert(one);
EXPECT_EQ(expected_constructed, decompose_constructed);
}
{ // insert(hint, T&&)
set1.insert(set1.begin(), 1);
EXPECT_EQ(expected_constructed, decompose_constructed);
}
{ // insert(hint, const T&)
set1.insert(set1.begin(), one);
EXPECT_EQ(expected_constructed, decompose_constructed);
}
{ // emplace(...)
set1.emplace(1);
EXPECT_EQ(expected_constructed, decompose_constructed);
set1.emplace("3");
expected_constructed += construct_three;
EXPECT_EQ(expected_constructed, decompose_constructed);
set1.emplace(one);
EXPECT_EQ(expected_constructed, decompose_constructed);
set1.emplace(three);
expected_constructed += construct_three;
EXPECT_EQ(expected_constructed, decompose_constructed);
}
{ // emplace_hint(...)
set1.emplace_hint(set1.begin(), 1);
EXPECT_EQ(expected_constructed, decompose_constructed);
set1.emplace_hint(set1.begin(), "3");
expected_constructed += construct_three;
EXPECT_EQ(expected_constructed, decompose_constructed);
set1.emplace_hint(set1.begin(), one);
EXPECT_EQ(expected_constructed, decompose_constructed);
set1.emplace_hint(set1.begin(), three);
expected_constructed += construct_three;
EXPECT_EQ(expected_constructed, decompose_constructed);
}
decompose_copy_constructed = 0;
decompose_copy_assigned = 0;
decompose_move_constructed = 0;
decompose_move_assigned = 0;
int expected_copy_constructed = 0;
int expected_move_constructed = 0;
{ // raw_hash_set(first, last) with random-access iterators
DecomposeSet set2(elem_vector.begin(), elem_vector.end());
// Expect exactly one copy-constructor call for each element if no
// rehashing is done.
expected_copy_constructed += elem_vector_count;
EXPECT_EQ(expected_copy_constructed, decompose_copy_constructed);
EXPECT_EQ(expected_move_constructed, decompose_move_constructed);
EXPECT_EQ(0, decompose_move_assigned);
EXPECT_EQ(0, decompose_copy_assigned);
}
{ // raw_hash_set(first, last) with forward iterators
std::list<DecomposeType> elem_list(elem_vector.begin(), elem_vector.end());
expected_copy_constructed = decompose_copy_constructed;
DecomposeSet set2(elem_list.begin(), elem_list.end());
// Expect exactly N elements copied into set, expect at most 2*N elements
// moving internally for all resizing needed (for a growth factor of 2).
expected_copy_constructed += elem_vector_count;
EXPECT_EQ(expected_copy_constructed, decompose_copy_constructed);
expected_move_constructed += elem_vector_count;
EXPECT_LT(expected_move_constructed, decompose_move_constructed);
expected_move_constructed += elem_vector_count;
EXPECT_GE(expected_move_constructed, decompose_move_constructed);
EXPECT_EQ(0, decompose_move_assigned);
EXPECT_EQ(0, decompose_copy_assigned);
expected_copy_constructed = decompose_copy_constructed;
expected_move_constructed = decompose_move_constructed;
}
{ // insert(first, last)
DecomposeSet set2;
set2.insert(elem_vector.begin(), elem_vector.end());
// Expect exactly N elements copied into set, expect at most 2*N elements
// moving internally for all resizing needed (for a growth factor of 2).
const int expected_new_elements = elem_vector_count;
const int expected_max_element_moves = 2 * elem_vector_count;
expected_copy_constructed += expected_new_elements;
EXPECT_EQ(expected_copy_constructed, decompose_copy_constructed);
expected_move_constructed += expected_max_element_moves;
EXPECT_GE(expected_move_constructed, decompose_move_constructed);
EXPECT_EQ(0, decompose_move_assigned);
EXPECT_EQ(0, decompose_copy_assigned);
expected_copy_constructed = decompose_copy_constructed;
expected_move_constructed = decompose_move_constructed;
}
}
TEST(Table, Decompose) {
if (SwisstableGenerationsEnabled()) {
GTEST_SKIP() << "Generations being enabled causes extra rehashes.";
}
TestDecompose<DecomposeHash, DecomposeEq>(false);
struct TransparentHashIntOverload {
size_t operator()(const DecomposeType& a) const { return a.i; }
size_t operator()(int a) const { return a; }
};
struct TransparentEqIntOverload {
bool operator()(const DecomposeType& a, const DecomposeType& b) const {
return a.i == b.i;
}
bool operator()(const DecomposeType& a, int b) const { return a.i == b; }
};
TestDecompose<TransparentHashIntOverload, DecomposeEq>(true);
TestDecompose<TransparentHashIntOverload, TransparentEqIntOverload>(true);
TestDecompose<DecomposeHash, TransparentEqIntOverload>(true);
}
// Returns the largest m such that a table with m elements has the same number
// of buckets as a table with n elements.
size_t MaxDensitySize(size_t n) {
IntTable t;
t.reserve(n);
for (size_t i = 0; i != n; ++i) t.emplace(i);
const size_t c = t.bucket_count();
while (c == t.bucket_count()) t.emplace(n++);
return t.size() - 1;
}
struct Modulo1000Hash {
size_t operator()(int x) const { return x % 1000; }
};
struct Modulo1000HashTable
: public raw_hash_set<IntPolicy, Modulo1000Hash, std::equal_to<int>,
std::allocator<int>> {};
// Test that rehash with no resize happen in case of many deleted slots.
TEST(Table, RehashWithNoResize) {
if (SwisstableGenerationsEnabled()) {
GTEST_SKIP() << "Generations being enabled causes extra rehashes.";
}
Modulo1000HashTable t;
// Adding the same length (and the same hash) strings
// to have at least kMinFullGroups groups
// with Group::kWidth collisions. Then fill up to MaxDensitySize;
const size_t kMinFullGroups = 7;
std::vector<int> keys;
for (size_t i = 0; i < MaxDensitySize(Group::kWidth * kMinFullGroups); ++i) {
int k = i * 1000;
t.emplace(k);
keys.push_back(k);
}
const size_t capacity = t.capacity();
// Remove elements from all groups except the first and the last one.
// All elements removed from full groups will be marked as ctrl_t::kDeleted.
const size_t erase_begin = Group::kWidth / 2;
const size_t erase_end = (t.size() / Group::kWidth - 1) * Group::kWidth;
for (size_t i = erase_begin; i < erase_end; ++i) {
EXPECT_EQ(1, t.erase(keys[i])) << i;
}
keys.erase(keys.begin() + erase_begin, keys.begin() + erase_end);
auto last_key = keys.back();
size_t last_key_num_probes = GetHashtableDebugNumProbes(t, last_key);
// Make sure that we have to make a lot of probes for last key.
ASSERT_GT(last_key_num_probes, kMinFullGroups);
int x = 1;
// Insert and erase one element, before inplace rehash happen.
while (last_key_num_probes == GetHashtableDebugNumProbes(t, last_key)) {
t.emplace(x);
ASSERT_EQ(capacity, t.capacity());
// All elements should be there.
ASSERT_TRUE(t.find(x) != t.end()) << x;
for (const auto& k : keys) {
ASSERT_TRUE(t.find(k) != t.end()) << k;
}
t.erase(x);
++x;
}
}
TEST(Table, InsertEraseStressTest) {
IntTable t;
const size_t kMinElementCount = 250;
std::deque<int> keys;
size_t i = 0;
for (; i < MaxDensitySize(kMinElementCount); ++i) {
t.emplace(i);
keys.push_back(i);
}
const size_t kNumIterations = 1000000;
for (; i < kNumIterations; ++i) {
ASSERT_EQ(1, t.erase(keys.front()));
keys.pop_front();
t.emplace(i);
keys.push_back(i);
}
}
TEST(Table, InsertOverloads) {
StringTable t;
// These should all trigger the insert(init_type) overload.
t.insert({{}, {}});
t.insert({"ABC", {}});
t.insert({"DEF", "!!!"});
EXPECT_THAT(t, UnorderedElementsAre(Pair("", ""), Pair("ABC", ""),
Pair("DEF", "!!!")));
}
TEST(Table, LargeTable) {
IntTable t;
for (int64_t i = 0; i != 100000; ++i) t.emplace(i << 40);
for (int64_t i = 0; i != 100000; ++i) ASSERT_EQ(i << 40, *t.find(i << 40));
}
// Timeout if copy is quadratic as it was in Rust.
TEST(Table, EnsureNonQuadraticAsInRust) {
static const size_t kLargeSize = 1 << 15;
IntTable t;
for (size_t i = 0; i != kLargeSize; ++i) {
t.insert(i);
}
// If this is quadratic, the test will timeout.
IntTable t2;
for (const auto& entry : t) t2.insert(entry);
}
TEST(Table, ClearBug) {
if (SwisstableGenerationsEnabled()) {
GTEST_SKIP() << "Generations being enabled causes extra rehashes.";
}
IntTable t;
constexpr size_t capacity = container_internal::Group::kWidth - 1;
constexpr size_t max_size = capacity / 2 + 1;
for (size_t i = 0; i < max_size; ++i) {
t.insert(i);
}
ASSERT_EQ(capacity, t.capacity());
intptr_t original = reinterpret_cast<intptr_t>(&*t.find(2));
t.clear();
ASSERT_EQ(capacity, t.capacity());
for (size_t i = 0; i < max_size; ++i) {
t.insert(i);
}
ASSERT_EQ(capacity, t.capacity());
intptr_t second = reinterpret_cast<intptr_t>(&*t.find(2));
// We are checking that original and second are close enough to each other
// that they are probably still in the same group. This is not strictly
// guaranteed.
EXPECT_LT(static_cast<size_t>(std::abs(original - second)),
capacity * sizeof(IntTable::value_type));
}
TEST(Table, Erase) {
IntTable t;
EXPECT_TRUE(t.find(0) == t.end());
auto res = t.emplace(0);
EXPECT_TRUE(res.second);
EXPECT_EQ(1, t.size());
t.erase(res.first);
EXPECT_EQ(0, t.size());
EXPECT_TRUE(t.find(0) == t.end());
}
TEST(Table, EraseMaintainsValidIterator) {
IntTable t;
const int kNumElements = 100;
for (int i = 0; i < kNumElements; i ++) {
EXPECT_TRUE(t.emplace(i).second);
}
EXPECT_EQ(t.size(), kNumElements);
int num_erase_calls = 0;
auto it = t.begin();
while (it != t.end()) {
t.erase(it++);
num_erase_calls++;
}
EXPECT_TRUE(t.empty());
EXPECT_EQ(num_erase_calls, kNumElements);
}
TEST(Table, EraseBeginEnd) {
IntTable t;
for (int i = 0; i < 10; ++i) t.insert(i);
EXPECT_EQ(t.size(), 10);
t.erase(t.begin(), t.end());
EXPECT_EQ(t.size(), 0);
}
// Collect N bad keys by following algorithm:
// 1. Create an empty table and reserve it to 2 * N.
// 2. Insert N random elements.
// 3. Take first Group::kWidth - 1 to bad_keys array.
// 4. Clear the table without resize.
// 5. Go to point 2 while N keys not collected
std::vector<int64_t> CollectBadMergeKeys(size_t N) {
static constexpr int kGroupSize = Group::kWidth - 1;
auto topk_range = [](size_t b, size_t e,
IntTable* t) -> std::vector<int64_t> {
for (size_t i = b; i != e; ++i) {
t->emplace(i);
}
std::vector<int64_t> res;
res.reserve(kGroupSize);
auto it = t->begin();
for (size_t i = b; i != e && i != b + kGroupSize; ++i, ++it) {
res.push_back(*it);
}
return res;
};
std::vector<int64_t> bad_keys;
bad_keys.reserve(N);
IntTable t;
t.reserve(N * 2);
for (size_t b = 0; bad_keys.size() < N; b += N) {
auto keys = topk_range(b, b + N, &t);
bad_keys.insert(bad_keys.end(), keys.begin(), keys.end());
t.erase(t.begin(), t.end());
EXPECT_TRUE(t.empty());
}
return bad_keys;
}
struct ProbeStats {
// Number of elements with specific probe length over all tested tables.
std::vector<size_t> all_probes_histogram;
// Ratios total_probe_length/size for every tested table.
std::vector<double> single_table_ratios;
// Average ratio total_probe_length/size over tables.
double AvgRatio() const {
return std::accumulate(single_table_ratios.begin(),
single_table_ratios.end(), 0.0) /
single_table_ratios.size();
}
// Maximum ratio total_probe_length/size over tables.
double MaxRatio() const {
return *std::max_element(single_table_ratios.begin(),
single_table_ratios.end());
}
// Percentile ratio total_probe_length/size over tables.
double PercentileRatio(double Percentile = 0.95) const {
auto r = single_table_ratios;
auto mid = r.begin() + static_cast<size_t>(r.size() * Percentile);
if (mid != r.end()) {
std::nth_element(r.begin(), mid, r.end());
return *mid;
} else {
return MaxRatio();
}
}
// Maximum probe length over all elements and all tables.
size_t MaxProbe() const { return all_probes_histogram.size(); }
// Fraction of elements with specified probe length.
std::vector<double> ProbeNormalizedHistogram() const {
double total_elements = std::accumulate(all_probes_histogram.begin(),
all_probes_histogram.end(), 0ull);
std::vector<double> res;
for (size_t p : all_probes_histogram) {
res.push_back(p / total_elements);
}
return res;
}
size_t PercentileProbe(double Percentile = 0.99) const {
size_t idx = 0;
for (double p : ProbeNormalizedHistogram()) {
if (Percentile > p) {
Percentile -= p;
++idx;
} else {
return idx;
}
}
return idx;
}
friend std::ostream& operator<<(std::ostream& out, const ProbeStats& s) {
out << "{AvgRatio:" << s.AvgRatio() << ", MaxRatio:" << s.MaxRatio()
<< ", PercentileRatio:" << s.PercentileRatio()
<< ", MaxProbe:" << s.MaxProbe() << ", Probes=[";
for (double p : s.ProbeNormalizedHistogram()) {
out << p << ",";
}
out << "]}";
return out;
}
};
struct ExpectedStats {
double avg_ratio;
double max_ratio;
std::vector<std::pair<double, double>> pecentile_ratios;
std::vector<std::pair<double, double>> pecentile_probes;
friend std::ostream& operator<<(std::ostream& out, const ExpectedStats& s) {
out << "{AvgRatio:" << s.avg_ratio << ", MaxRatio:" << s.max_ratio
<< ", PercentileRatios: [";
for (auto el : s.pecentile_ratios) {
out << el.first << ":" << el.second << ", ";
}
out << "], PercentileProbes: [";
for (auto el : s.pecentile_probes) {
out << el.first << ":" << el.second << ", ";
}
out << "]}";
return out;
}
};
void VerifyStats(size_t size, const ExpectedStats& exp,
const ProbeStats& stats) {
EXPECT_LT(stats.AvgRatio(), exp.avg_ratio) << size << " " << stats;
EXPECT_LT(stats.MaxRatio(), exp.max_ratio) << size << " " << stats;
for (auto pr : exp.pecentile_ratios) {
EXPECT_LE(stats.PercentileRatio(pr.first), pr.second)
<< size << " " << pr.first << " " << stats;
}
for (auto pr : exp.pecentile_probes) {
EXPECT_LE(stats.PercentileProbe(pr.first), pr.second)
<< size << " " << pr.first << " " << stats;
}
}
using ProbeStatsPerSize = std::map<size_t, ProbeStats>;
// Collect total ProbeStats on num_iters iterations of the following algorithm:
// 1. Create new table and reserve it to keys.size() * 2
// 2. Insert all keys xored with seed
// 3. Collect ProbeStats from final table.
ProbeStats CollectProbeStatsOnKeysXoredWithSeed(
const std::vector<int64_t>& keys, size_t num_iters) {
const size_t reserve_size = keys.size() * 2;
ProbeStats stats;
int64_t seed = 0x71b1a19b907d6e33;
while (num_iters--) {
seed = static_cast<int64_t>(static_cast<uint64_t>(seed) * 17 + 13);
IntTable t1;
t1.reserve(reserve_size);
for (const auto& key : keys) {
t1.emplace(key ^ seed);
}
auto probe_histogram = GetHashtableDebugNumProbesHistogram(t1);
stats.all_probes_histogram.resize(
std::max(stats.all_probes_histogram.size(), probe_histogram.size()));
std::transform(probe_histogram.begin(), probe_histogram.end(),
stats.all_probes_histogram.begin(),
stats.all_probes_histogram.begin(), std::plus<size_t>());
size_t total_probe_seq_length = 0;
for (size_t i = 0; i < probe_histogram.size(); ++i) {
total_probe_seq_length += i * probe_histogram[i];
}
stats.single_table_ratios.push_back(total_probe_seq_length * 1.0 /
keys.size());
t1.erase(t1.begin(), t1.end());
}
return stats;
}
ExpectedStats XorSeedExpectedStats() {
constexpr bool kRandomizesInserts =
#ifdef NDEBUG
false;
#else // NDEBUG
true;
#endif // NDEBUG
// The effective load factor is larger in non-opt mode because we insert
// elements out of order.
switch (container_internal::Group::kWidth) {
case 8:
if (kRandomizesInserts) {
return {0.05,
1.0,
{{0.95, 0.5}},
{{0.95, 0}, {0.99, 2}, {0.999, 4}, {0.9999, 10}}};
} else {
return {0.05,
2.0,
{{0.95, 0.1}},
{{0.95, 0}, {0.99, 2}, {0.999, 4}, {0.9999, 10}}};
}
case 16:
if (kRandomizesInserts) {
return {0.1,
2.0,
{{0.95, 0.1}},
{{0.95, 0}, {0.99, 1}, {0.999, 8}, {0.9999, 15}}};
} else {
return {0.05,
1.0,
{{0.95, 0.05}},
{{0.95, 0}, {0.99, 1}, {0.999, 4}, {0.9999, 10}}};
}
}
LOG(FATAL) << "Unknown Group width";
return {};
}
// TODO(b/80415403): Figure out why this test is so flaky, esp. on MSVC
TEST(Table, DISABLED_EnsureNonQuadraticTopNXorSeedByProbeSeqLength) {
ProbeStatsPerSize stats;
std::vector<size_t> sizes = {Group::kWidth << 5, Group::kWidth << 10};
for (size_t size : sizes) {
stats[size] =
CollectProbeStatsOnKeysXoredWithSeed(CollectBadMergeKeys(size), 200);
}
auto expected = XorSeedExpectedStats();
for (size_t size : sizes) {
auto& stat = stats[size];
VerifyStats(size, expected, stat);
LOG(INFO) << size << " " << stat;
}
}
// Collect total ProbeStats on num_iters iterations of the following algorithm:
// 1. Create new table
// 2. Select 10% of keys and insert 10 elements key * 17 + j * 13
// 3. Collect ProbeStats from final table
ProbeStats CollectProbeStatsOnLinearlyTransformedKeys(
const std::vector<int64_t>& keys, size_t num_iters) {
ProbeStats stats;
std::random_device rd;
std::mt19937 rng(rd());
auto linear_transform = [](size_t x, size_t y) { return x * 17 + y * 13; };
std::uniform_int_distribution<size_t> dist(0, keys.size()-1);
while (num_iters--) {
IntTable t1;
size_t num_keys = keys.size() / 10;
size_t start = dist(rng);
for (size_t i = 0; i != num_keys; ++i) {
for (size_t j = 0; j != 10; ++j) {
t1.emplace(linear_transform(keys[(i + start) % keys.size()], j));
}
}
auto probe_histogram = GetHashtableDebugNumProbesHistogram(t1);
stats.all_probes_histogram.resize(
std::max(stats.all_probes_histogram.size(), probe_histogram.size()));
std::transform(probe_histogram.begin(), probe_histogram.end(),
stats.all_probes_histogram.begin(),
stats.all_probes_histogram.begin(), std::plus<size_t>());
size_t total_probe_seq_length = 0;
for (size_t i = 0; i < probe_histogram.size(); ++i) {
total_probe_seq_length += i * probe_histogram[i];
}
stats.single_table_ratios.push_back(total_probe_seq_length * 1.0 /
t1.size());
t1.erase(t1.begin(), t1.end());
}
return stats;
}
ExpectedStats LinearTransformExpectedStats() {
constexpr bool kRandomizesInserts =
#ifdef NDEBUG
false;
#else // NDEBUG
true;
#endif // NDEBUG
// The effective load factor is larger in non-opt mode because we insert
// elements out of order.
switch (container_internal::Group::kWidth) {
case 8:
if (kRandomizesInserts) {
return {0.1,
0.5,
{{0.95, 0.3}},
{{0.95, 0}, {0.99, 1}, {0.999, 8}, {0.9999, 15}}};
} else {
return {0.4,
0.6,
{{0.95, 0.5}},
{{0.95, 1}, {0.99, 14}, {0.999, 23}, {0.9999, 26}}};
}
case 16:
if (kRandomizesInserts) {
return {0.1,
0.4,
{{0.95, 0.3}},
{{0.95, 1}, {0.99, 2}, {0.999, 9}, {0.9999, 15}}};
} else {
return {0.05,
0.2,
{{0.95, 0.1}},
{{0.95, 0}, {0.99, 1}, {0.999, 6}, {0.9999, 10}}};
}
}
LOG(FATAL) << "Unknown Group width";
return {};
}
// TODO(b/80415403): Figure out why this test is so flaky.
TEST(Table, DISABLED_EnsureNonQuadraticTopNLinearTransformByProbeSeqLength) {
ProbeStatsPerSize stats;
std::vector<size_t> sizes = {Group::kWidth << 5, Group::kWidth << 10};
for (size_t size : sizes) {
stats[size] = CollectProbeStatsOnLinearlyTransformedKeys(
CollectBadMergeKeys(size), 300);
}
auto expected = LinearTransformExpectedStats();
for (size_t size : sizes) {
auto& stat = stats[size];
VerifyStats(size, expected, stat);
LOG(INFO) << size << " " << stat;
}
}
TEST(Table, EraseCollision) {
BadTable t;
// 1 2 3
t.emplace(1);
t.emplace(2);
t.emplace(3);
EXPECT_THAT(*t.find(1), 1);
EXPECT_THAT(*t.find(2), 2);
EXPECT_THAT(*t.find(3), 3);
EXPECT_EQ(3, t.size());
// 1 DELETED 3
t.erase(t.find(2));
EXPECT_THAT(*t.find(1), 1);
EXPECT_TRUE(t.find(2) == t.end());
EXPECT_THAT(*t.find(3), 3);
EXPECT_EQ(2, t.size());
// DELETED DELETED 3
t.erase(t.find(1));
EXPECT_TRUE(t.find(1) == t.end());
EXPECT_TRUE(t.find(2) == t.end());
EXPECT_THAT(*t.find(3), 3);
EXPECT_EQ(1, t.size());
// DELETED DELETED DELETED
t.erase(t.find(3));
EXPECT_TRUE(t.find(1) == t.end());
EXPECT_TRUE(t.find(2) == t.end());
EXPECT_TRUE(t.find(3) == t.end());
EXPECT_EQ(0, t.size());
}
TEST(Table, EraseInsertProbing) {
BadTable t(100);
// 1 2 3 4
t.emplace(1);
t.emplace(2);
t.emplace(3);
t.emplace(4);
// 1 DELETED 3 DELETED
t.erase(t.find(2));
t.erase(t.find(4));
// 1 10 3 11 12
t.emplace(10);
t.emplace(11);
t.emplace(12);
EXPECT_EQ(5, t.size());
EXPECT_THAT(t, UnorderedElementsAre(1, 10, 3, 11, 12));
}
TEST(Table, Clear) {
IntTable t;
EXPECT_TRUE(t.find(0) == t.end());
t.clear();
EXPECT_TRUE(t.find(0) == t.end());
auto res = t.emplace(0);
EXPECT_TRUE(res.second);
EXPECT_EQ(1, t.size());
t.clear();
EXPECT_EQ(0, t.size());
EXPECT_TRUE(t.find(0) == t.end());
}
TEST(Table, Swap) {
IntTable t;
EXPECT_TRUE(t.find(0) == t.end());
auto res = t.emplace(0);
EXPECT_TRUE(res.second);
EXPECT_EQ(1, t.size());
IntTable u;
t.swap(u);
EXPECT_EQ(0, t.size());
EXPECT_EQ(1, u.size());
EXPECT_TRUE(t.find(0) == t.end());
EXPECT_THAT(*u.find(0), 0);
}
TEST(Table, Rehash) {
IntTable t;
EXPECT_TRUE(t.find(0) == t.end());
t.emplace(0);
t.emplace(1);
EXPECT_EQ(2, t.size());
t.rehash(128);
EXPECT_EQ(2, t.size());
EXPECT_THAT(*t.find(0), 0);
EXPECT_THAT(*t.find(1), 1);
}
TEST(Table, RehashDoesNotRehashWhenNotNecessary) {
IntTable t;
t.emplace(0);
t.emplace(1);
auto* p = &*t.find(0);
t.rehash(1);
EXPECT_EQ(p, &*t.find(0));
}
TEST(Table, RehashZeroDoesNotAllocateOnEmptyTable) {
IntTable t;
t.rehash(0);
EXPECT_EQ(0, t.bucket_count());
}
TEST(Table, RehashZeroDeallocatesEmptyTable) {
IntTable t;
t.emplace(0);
t.clear();
EXPECT_NE(0, t.bucket_count());
t.rehash(0);
EXPECT_EQ(0, t.bucket_count());
}
TEST(Table, RehashZeroForcesRehash) {
IntTable t;
t.emplace(0);
t.emplace(1);
auto* p = &*t.find(0);
t.rehash(0);
EXPECT_NE(p, &*t.find(0));
}
TEST(Table, ConstructFromInitList) {
using P = std::pair<std::string, std::string>;
struct Q {
operator P() const { return {}; } // NOLINT
};
StringTable t = {P(), Q(), {}, {{}, {}}};
}
TEST(Table, CopyConstruct) {
IntTable t;
t.emplace(0);
EXPECT_EQ(1, t.size());
{
IntTable u(t);
EXPECT_EQ(1, u.size());
EXPECT_THAT(*u.find(0), 0);
}
{
IntTable u{t};
EXPECT_EQ(1, u.size());
EXPECT_THAT(*u.find(0), 0);
}
{
IntTable u = t;
EXPECT_EQ(1, u.size());
EXPECT_THAT(*u.find(0), 0);
}
}
TEST(Table, CopyConstructWithAlloc) {
StringTable t;
t.emplace("a", "b");
EXPECT_EQ(1, t.size());
StringTable u(t, Alloc<std::pair<std::string, std::string>>());
EXPECT_EQ(1, u.size());
EXPECT_THAT(*u.find("a"), Pair("a", "b"));
}
struct ExplicitAllocIntTable
: raw_hash_set<IntPolicy, container_internal::hash_default_hash<int64_t>,
std::equal_to<int64_t>, Alloc<int64_t>> {
ExplicitAllocIntTable() = default;
};
TEST(Table, AllocWithExplicitCtor) {
ExplicitAllocIntTable t;
EXPECT_EQ(0, t.size());
}
TEST(Table, MoveConstruct) {
{
StringTable t;
t.emplace("a", "b");
EXPECT_EQ(1, t.size());
StringTable u(std::move(t));
EXPECT_EQ(1, u.size());
EXPECT_THAT(*u.find("a"), Pair("a", "b"));
}
{
StringTable t;
t.emplace("a", "b");
EXPECT_EQ(1, t.size());
StringTable u{std::move(t)};
EXPECT_EQ(1, u.size());
EXPECT_THAT(*u.find("a"), Pair("a", "b"));
}
{
StringTable t;
t.emplace("a", "b");
EXPECT_EQ(1, t.size());
StringTable u = std::move(t);
EXPECT_EQ(1, u.size());
EXPECT_THAT(*u.find("a"), Pair("a", "b"));
}
}
TEST(Table, MoveConstructWithAlloc) {
StringTable t;
t.emplace("a", "b");
EXPECT_EQ(1, t.size());
StringTable u(std::move(t), Alloc<std::pair<std::string, std::string>>());
EXPECT_EQ(1, u.size());
EXPECT_THAT(*u.find("a"), Pair("a", "b"));
}
TEST(Table, CopyAssign) {
StringTable t;
t.emplace("a", "b");
EXPECT_EQ(1, t.size());
StringTable u;
u = t;
EXPECT_EQ(1, u.size());
EXPECT_THAT(*u.find("a"), Pair("a", "b"));
}
TEST(Table, CopySelfAssign) {
StringTable t;
t.emplace("a", "b");
EXPECT_EQ(1, t.size());
t = *&t;
EXPECT_EQ(1, t.size());
EXPECT_THAT(*t.find("a"), Pair("a", "b"));
}
TEST(Table, MoveAssign) {
StringTable t;
t.emplace("a", "b");
EXPECT_EQ(1, t.size());
StringTable u;
u = std::move(t);
EXPECT_EQ(1, u.size());
EXPECT_THAT(*u.find("a"), Pair("a", "b"));
}
TEST(Table, Equality) {
StringTable t;
std::vector<std::pair<std::string, std::string>> v = {{"a", "b"},
{"aa", "bb"}};
t.insert(std::begin(v), std::end(v));
StringTable u = t;
EXPECT_EQ(u, t);
}
TEST(Table, Equality2) {
StringTable t;
std::vector<std::pair<std::string, std::string>> v1 = {{"a", "b"},
{"aa", "bb"}};
t.insert(std::begin(v1), std::end(v1));
StringTable u;
std::vector<std::pair<std::string, std::string>> v2 = {{"a", "a"},
{"aa", "aa"}};
u.insert(std::begin(v2), std::end(v2));
EXPECT_NE(u, t);
}
TEST(Table, Equality3) {
StringTable t;
std::vector<std::pair<std::string, std::string>> v1 = {{"b", "b"},
{"bb", "bb"}};
t.insert(std::begin(v1), std::end(v1));
StringTable u;
std::vector<std::pair<std::string, std::string>> v2 = {{"a", "a"},
{"aa", "aa"}};
u.insert(std::begin(v2), std::end(v2));
EXPECT_NE(u, t);
}
TEST(Table, NumDeletedRegression) {
IntTable t;
t.emplace(0);
t.erase(t.find(0));
// construct over a deleted slot.
t.emplace(0);
t.clear();
}
TEST(Table, FindFullDeletedRegression) {
IntTable t;
for (int i = 0; i < 1000; ++i) {
t.emplace(i);
t.erase(t.find(i));
}
EXPECT_EQ(0, t.size());
}
TEST(Table, ReplacingDeletedSlotDoesNotRehash) {
size_t n;
{
// Compute n such that n is the maximum number of elements before rehash.
IntTable t;
t.emplace(0);
size_t c = t.bucket_count();
for (n = 1; c == t.bucket_count(); ++n) t.emplace(n);
--n;
}
IntTable t;
t.rehash(n);
const size_t c = t.bucket_count();
for (size_t i = 0; i != n; ++i) t.emplace(i);
EXPECT_EQ(c, t.bucket_count()) << "rehashing threshold = " << n;
t.erase(0);
t.emplace(0);
EXPECT_EQ(c, t.bucket_count()) << "rehashing threshold = " << n;
}
TEST(Table, NoThrowMoveConstruct) {
ASSERT_TRUE(
std::is_nothrow_copy_constructible<absl::Hash<absl::string_view>>::value);
ASSERT_TRUE(std::is_nothrow_copy_constructible<
std::equal_to<absl::string_view>>::value);
ASSERT_TRUE(std::is_nothrow_copy_constructible<std::allocator<int>>::value);
EXPECT_TRUE(std::is_nothrow_move_constructible<StringTable>::value);
}
TEST(Table, NoThrowMoveAssign) {
ASSERT_TRUE(
std::is_nothrow_move_assignable<absl::Hash<absl::string_view>>::value);
ASSERT_TRUE(
std::is_nothrow_move_assignable<std::equal_to<absl::string_view>>::value);
ASSERT_TRUE(std::is_nothrow_move_assignable<std::allocator<int>>::value);
ASSERT_TRUE(
absl::allocator_traits<std::allocator<int>>::is_always_equal::value);
EXPECT_TRUE(std::is_nothrow_move_assignable<StringTable>::value);
}
TEST(Table, NoThrowSwappable) {
ASSERT_TRUE(
container_internal::IsNoThrowSwappable<absl::Hash<absl::string_view>>());
ASSERT_TRUE(container_internal::IsNoThrowSwappable<
std::equal_to<absl::string_view>>());
ASSERT_TRUE(container_internal::IsNoThrowSwappable<std::allocator<int>>());
EXPECT_TRUE(container_internal::IsNoThrowSwappable<StringTable>());
}
TEST(Table, HeterogeneousLookup) {
struct Hash {
size_t operator()(int64_t i) const { return i; }
size_t operator()(double i) const {
ADD_FAILURE();
return i;
}
};
struct Eq {
bool operator()(int64_t a, int64_t b) const { return a == b; }
bool operator()(double a, int64_t b) const {
ADD_FAILURE();
return a == b;
}
bool operator()(int64_t a, double b) const {
ADD_FAILURE();
return a == b;
}
bool operator()(double a, double b) const {
ADD_FAILURE();
return a == b;
}
};
struct THash {
using is_transparent = void;
size_t operator()(int64_t i) const { return i; }
size_t operator()(double i) const { return i; }
};
struct TEq {
using is_transparent = void;
bool operator()(int64_t a, int64_t b) const { return a == b; }
bool operator()(double a, int64_t b) const { return a == b; }
bool operator()(int64_t a, double b) const { return a == b; }
bool operator()(double a, double b) const { return a == b; }
};
raw_hash_set<IntPolicy, Hash, Eq, Alloc<int64_t>> s{0, 1, 2};
// It will convert to int64_t before the query.
EXPECT_EQ(1, *s.find(double{1.1}));
raw_hash_set<IntPolicy, THash, TEq, Alloc<int64_t>> ts{0, 1, 2};
// It will try to use the double, and fail to find the object.
EXPECT_TRUE(ts.find(1.1) == ts.end());
}
template <class Table>
using CallFind = decltype(std::declval<Table&>().find(17));
template <class Table>
using CallErase = decltype(std::declval<Table&>().erase(17));
template <class Table>
using CallExtract = decltype(std::declval<Table&>().extract(17));
template <class Table>
using CallPrefetch = decltype(std::declval<Table&>().prefetch(17));
template <class Table>
using CallCount = decltype(std::declval<Table&>().count(17));
template <template <typename> class C, class Table, class = void>
struct VerifyResultOf : std::false_type {};
template <template <typename> class C, class Table>
struct VerifyResultOf<C, Table, absl::void_t<C<Table>>> : std::true_type {};
TEST(Table, HeterogeneousLookupOverloads) {
using NonTransparentTable =
raw_hash_set<StringPolicy, absl::Hash<absl::string_view>,
std::equal_to<absl::string_view>, std::allocator<int>>;
EXPECT_FALSE((VerifyResultOf<CallFind, NonTransparentTable>()));
EXPECT_FALSE((VerifyResultOf<CallErase, NonTransparentTable>()));
EXPECT_FALSE((VerifyResultOf<CallExtract, NonTransparentTable>()));
EXPECT_FALSE((VerifyResultOf<CallPrefetch, NonTransparentTable>()));
EXPECT_FALSE((VerifyResultOf<CallCount, NonTransparentTable>()));
using TransparentTable = raw_hash_set<
StringPolicy,
absl::container_internal::hash_default_hash<absl::string_view>,
absl::container_internal::hash_default_eq<absl::string_view>,
std::allocator<int>>;
EXPECT_TRUE((VerifyResultOf<CallFind, TransparentTable>()));
EXPECT_TRUE((VerifyResultOf<CallErase, TransparentTable>()));
EXPECT_TRUE((VerifyResultOf<CallExtract, TransparentTable>()));
EXPECT_TRUE((VerifyResultOf<CallPrefetch, TransparentTable>()));
EXPECT_TRUE((VerifyResultOf<CallCount, TransparentTable>()));
}
TEST(Iterator, IsDefaultConstructible) {
StringTable::iterator i;
EXPECT_TRUE(i == StringTable::iterator());
}
TEST(ConstIterator, IsDefaultConstructible) {
StringTable::const_iterator i;
EXPECT_TRUE(i == StringTable::const_iterator());
}
TEST(Iterator, ConvertsToConstIterator) {
StringTable::iterator i;
EXPECT_TRUE(i == StringTable::const_iterator());
}
TEST(Iterator, Iterates) {
IntTable t;
for (size_t i = 3; i != 6; ++i) EXPECT_TRUE(t.emplace(i).second);
EXPECT_THAT(t, UnorderedElementsAre(3, 4, 5));
}
TEST(Table, Merge) {
StringTable t1, t2;
t1.emplace("0", "-0");
t1.emplace("1", "-1");
t2.emplace("0", "~0");
t2.emplace("2", "~2");
EXPECT_THAT(t1, UnorderedElementsAre(Pair("0", "-0"), Pair("1", "-1")));
EXPECT_THAT(t2, UnorderedElementsAre(Pair("0", "~0"), Pair("2", "~2")));
t1.merge(t2);
EXPECT_THAT(t1, UnorderedElementsAre(Pair("0", "-0"), Pair("1", "-1"),
Pair("2", "~2")));
EXPECT_THAT(t2, UnorderedElementsAre(Pair("0", "~0")));
}
TEST(Table, IteratorEmplaceConstructibleRequirement) {
struct Value {
explicit Value(absl::string_view view) : value(view) {}
std::string value;
bool operator==(const Value& other) const { return value == other.value; }
};
struct H {
size_t operator()(const Value& v) const {
return absl::Hash<std::string>{}(v.value);
}
};
struct Table : raw_hash_set<ValuePolicy<Value>, H, std::equal_to<Value>,
std::allocator<Value>> {
using Base = typename Table::raw_hash_set;
using Base::Base;
};
std::string input[3]{"A", "B", "C"};
Table t(std::begin(input), std::end(input));
EXPECT_THAT(t, UnorderedElementsAre(Value{"A"}, Value{"B"}, Value{"C"}));
input[0] = "D";
input[1] = "E";
input[2] = "F";
t.insert(std::begin(input), std::end(input));
EXPECT_THAT(t, UnorderedElementsAre(Value{"A"}, Value{"B"}, Value{"C"},
Value{"D"}, Value{"E"}, Value{"F"}));
}
TEST(Nodes, EmptyNodeType) {
using node_type = StringTable::node_type;
node_type n;
EXPECT_FALSE(n);
EXPECT_TRUE(n.empty());
EXPECT_TRUE((std::is_same<node_type::allocator_type,
StringTable::allocator_type>::value));
}
TEST(Nodes, ExtractInsert) {
constexpr char k0[] = "Very long string zero.";
constexpr char k1[] = "Very long string one.";
constexpr char k2[] = "Very long string two.";
StringTable t = {{k0, ""}, {k1, ""}, {k2, ""}};
EXPECT_THAT(t,
UnorderedElementsAre(Pair(k0, ""), Pair(k1, ""), Pair(k2, "")));
auto node = t.extract(k0);
EXPECT_THAT(t, UnorderedElementsAre(Pair(k1, ""), Pair(k2, "")));
EXPECT_TRUE(node);
EXPECT_FALSE(node.empty());
StringTable t2;
StringTable::insert_return_type res = t2.insert(std::move(node));
EXPECT_TRUE(res.inserted);
EXPECT_THAT(*res.position, Pair(k0, ""));
EXPECT_FALSE(res.node);
EXPECT_THAT(t2, UnorderedElementsAre(Pair(k0, "")));
// Not there.
EXPECT_THAT(t, UnorderedElementsAre(Pair(k1, ""), Pair(k2, "")));
node = t.extract("Not there!");
EXPECT_THAT(t, UnorderedElementsAre(Pair(k1, ""), Pair(k2, "")));
EXPECT_FALSE(node);
// Inserting nothing.
res = t2.insert(std::move(node));
EXPECT_FALSE(res.inserted);
EXPECT_EQ(res.position, t2.end());
EXPECT_FALSE(res.node);
EXPECT_THAT(t2, UnorderedElementsAre(Pair(k0, "")));
t.emplace(k0, "1");
node = t.extract(k0);
// Insert duplicate.
res = t2.insert(std::move(node));
EXPECT_FALSE(res.inserted);
EXPECT_THAT(*res.position, Pair(k0, ""));
EXPECT_TRUE(res.node);
EXPECT_FALSE(node); // NOLINT(bugprone-use-after-move)
}
TEST(Nodes, HintInsert) {
IntTable t = {1, 2, 3};
auto node = t.extract(1);
EXPECT_THAT(t, UnorderedElementsAre(2, 3));
auto it = t.insert(t.begin(), std::move(node));
EXPECT_THAT(t, UnorderedElementsAre(1, 2, 3));
EXPECT_EQ(*it, 1);
EXPECT_FALSE(node); // NOLINT(bugprone-use-after-move)
node = t.extract(2);
EXPECT_THAT(t, UnorderedElementsAre(1, 3));
// reinsert 2 to make the next insert fail.
t.insert(2);
EXPECT_THAT(t, UnorderedElementsAre(1, 2, 3));
it = t.insert(t.begin(), std::move(node));
EXPECT_EQ(*it, 2);
// The node was not emptied by the insert call.
EXPECT_TRUE(node); // NOLINT(bugprone-use-after-move)
}
IntTable MakeSimpleTable(size_t size) {
IntTable t;
while (t.size() < size) t.insert(t.size());
return t;
}
std::vector<int> OrderOfIteration(const IntTable& t) {
return {t.begin(), t.end()};
}
// These IterationOrderChanges tests depend on non-deterministic behavior.
// We are injecting non-determinism from the pointer of the table, but do so in
// a way that only the page matters. We have to retry enough times to make sure
// we are touching different memory pages to cause the ordering to change.
// We also need to keep the old tables around to avoid getting the same memory
// blocks over and over.
TEST(Table, IterationOrderChangesByInstance) {
for (size_t size : {2, 6, 12, 20}) {
const auto reference_table = MakeSimpleTable(size);
const auto reference = OrderOfIteration(reference_table);
std::vector<IntTable> tables;
bool found_difference = false;
for (int i = 0; !found_difference && i < 5000; ++i) {
tables.push_back(MakeSimpleTable(size));
found_difference = OrderOfIteration(tables.back()) != reference;
}
if (!found_difference) {
FAIL()
<< "Iteration order remained the same across many attempts with size "
<< size;
}
}
}
TEST(Table, IterationOrderChangesOnRehash) {
std::vector<IntTable> garbage;
for (int i = 0; i < 5000; ++i) {
auto t = MakeSimpleTable(20);
const auto reference = OrderOfIteration(t);
// Force rehash to the same size.
t.rehash(0);
auto trial = OrderOfIteration(t);
if (trial != reference) {
// We are done.
return;
}
garbage.push_back(std::move(t));
}
FAIL() << "Iteration order remained the same across many attempts.";
}
// Verify that pointers are invalidated as soon as a second element is inserted.
// This prevents dependency on pointer stability on small tables.
TEST(Table, UnstablePointers) {
IntTable table;
const auto addr = [&](int i) {
return reinterpret_cast<uintptr_t>(&*table.find(i));
};
table.insert(0);
const uintptr_t old_ptr = addr(0);
// This causes a rehash.
table.insert(1);
EXPECT_NE(old_ptr, addr(0));
}
TEST(TableDeathTest, InvalidIteratorAsserts) {
if (!IsAssertEnabled() && !SwisstableGenerationsEnabled())
GTEST_SKIP() << "Assertions not enabled.";
IntTable t;
// Extra simple "regexp" as regexp support is highly varied across platforms.
EXPECT_DEATH_IF_SUPPORTED(t.erase(t.end()),
"erase.* called on end.. iterator.");
typename IntTable::iterator iter;
EXPECT_DEATH_IF_SUPPORTED(
++iter, "operator.* called on default-constructed iterator.");
t.insert(0);
iter = t.begin();
t.erase(iter);
const char* const kErasedDeathMessage =
SwisstableGenerationsEnabled()
? "operator.* called on invalid iterator.*was likely erased"
: "operator.* called on invalid iterator.*might have been "
"erased.*config=asan";
EXPECT_DEATH_IF_SUPPORTED(++iter, kErasedDeathMessage);
}
// Invalid iterator use can trigger heap-use-after-free in asan,
// use-of-uninitialized-value in msan, or invalidated iterator assertions.
constexpr const char* kInvalidIteratorDeathMessage =
"heap-use-after-free|use-of-uninitialized-value|invalidated "
"iterator|Invalid iterator|invalid iterator";
// MSVC doesn't support | in regex.
#if defined(_MSC_VER)
constexpr bool kMsvc = true;
#else
constexpr bool kMsvc = false;
#endif
TEST(TableDeathTest, IteratorInvalidAssertsEqualityOperator) {
if (!IsAssertEnabled() && !SwisstableGenerationsEnabled())
GTEST_SKIP() << "Assertions not enabled.";
IntTable t;
t.insert(1);
t.insert(2);
t.insert(3);
auto iter1 = t.begin();
auto iter2 = std::next(iter1);
ASSERT_NE(iter1, t.end());
ASSERT_NE(iter2, t.end());
t.erase(iter1);
// Extra simple "regexp" as regexp support is highly varied across platforms.
const char* const kErasedDeathMessage =
SwisstableGenerationsEnabled()
? "Invalid iterator comparison.*was likely erased"
: "Invalid iterator comparison.*might have been erased.*config=asan";
EXPECT_DEATH_IF_SUPPORTED(void(iter1 == iter2), kErasedDeathMessage);
EXPECT_DEATH_IF_SUPPORTED(void(iter2 != iter1), kErasedDeathMessage);
t.erase(iter2);
EXPECT_DEATH_IF_SUPPORTED(void(iter1 == iter2), kErasedDeathMessage);
IntTable t1, t2;
t1.insert(0);
t2.insert(0);
iter1 = t1.begin();
iter2 = t2.begin();
const char* const kContainerDiffDeathMessage =
SwisstableGenerationsEnabled()
? "Invalid iterator comparison.*iterators from different hashtables"
: "Invalid iterator comparison.*may be from different "
".*containers.*config=asan";
EXPECT_DEATH_IF_SUPPORTED(void(iter1 == iter2), kContainerDiffDeathMessage);
EXPECT_DEATH_IF_SUPPORTED(void(iter2 == iter1), kContainerDiffDeathMessage);
for (int i = 0; i < 10; ++i) t1.insert(i);
// There should have been a rehash in t1.
if (kMsvc) return; // MSVC doesn't support | in regex.
// NOTE(b/293887834): After rehashing, iterators will contain pointers to
// freed memory, which may be detected by ThreadSanitizer.
const char* const kRehashedDeathMessage =
SwisstableGenerationsEnabled()
? kInvalidIteratorDeathMessage
: "Invalid iterator comparison.*might have rehashed.*config=asan"
"|ThreadSanitizer: heap-use-after-free";
EXPECT_DEATH_IF_SUPPORTED(void(iter1 == t1.begin()), kRehashedDeathMessage);
}
#if defined(ABSL_INTERNAL_HASHTABLEZ_SAMPLE)
TEST(RawHashSamplerTest, Sample) {
// Enable the feature even if the prod default is off.
SetHashtablezEnabled(true);
SetHashtablezSampleParameter(100);
auto& sampler = GlobalHashtablezSampler();
size_t start_size = 0;
absl::flat_hash_set<const HashtablezInfo*> preexisting_info;
start_size += sampler.Iterate([&](const HashtablezInfo& info) {
preexisting_info.insert(&info);
++start_size;
});
std::vector<IntTable> tables;
for (int i = 0; i < 1000000; ++i) {
tables.emplace_back();
const bool do_reserve = (i % 10 > 5);
const bool do_rehash = !do_reserve && (i % 10 > 0);
if (do_reserve) {
// Don't reserve on all tables.
tables.back().reserve(10 * (i % 10));
}
tables.back().insert(1);
tables.back().insert(i % 5);
if (do_rehash) {
// Rehash some other tables.
tables.back().rehash(10 * (i % 10));
}
}
size_t end_size = 0;
absl::flat_hash_map<size_t, int> observed_checksums;
absl::flat_hash_map<ssize_t, int> reservations;
end_size += sampler.Iterate([&](const HashtablezInfo& info) {
if (preexisting_info.count(&info) == 0) {
observed_checksums[info.hashes_bitwise_xor.load(
std::memory_order_relaxed)]++;
reservations[info.max_reserve.load(std::memory_order_relaxed)]++;
}
EXPECT_EQ(info.inline_element_size, sizeof(int64_t));
++end_size;
});
EXPECT_NEAR((end_size - start_size) / static_cast<double>(tables.size()),
0.01, 0.005);
EXPECT_EQ(observed_checksums.size(), 5);
for (const auto& [_, count] : observed_checksums) {
EXPECT_NEAR((100 * count) / static_cast<double>(tables.size()), 0.2, 0.05);
}
EXPECT_EQ(reservations.size(), 10);
for (const auto& [reservation, count] : reservations) {
EXPECT_GE(reservation, 0);
EXPECT_LT(reservation, 100);
EXPECT_NEAR((100 * count) / static_cast<double>(tables.size()), 0.1, 0.05)
<< reservation;
}
}
#endif // ABSL_INTERNAL_HASHTABLEZ_SAMPLE
TEST(RawHashSamplerTest, DoNotSampleCustomAllocators) {
// Enable the feature even if the prod default is off.
SetHashtablezEnabled(true);
SetHashtablezSampleParameter(100);
auto& sampler = GlobalHashtablezSampler();
size_t start_size = 0;
start_size += sampler.Iterate([&](const HashtablezInfo&) { ++start_size; });
std::vector<CustomAllocIntTable> tables;
for (int i = 0; i < 1000000; ++i) {
tables.emplace_back();
tables.back().insert(1);
}
size_t end_size = 0;
end_size += sampler.Iterate([&](const HashtablezInfo&) { ++end_size; });
EXPECT_NEAR((end_size - start_size) / static_cast<double>(tables.size()),
0.00, 0.001);
}
#ifdef ABSL_HAVE_ADDRESS_SANITIZER
TEST(Sanitizer, PoisoningUnused) {
IntTable t;
t.reserve(5);
// Insert something to force an allocation.
int64_t& v1 = *t.insert(0).first;
// Make sure there is something to test.
ASSERT_GT(t.capacity(), 1);
int64_t* slots = RawHashSetTestOnlyAccess::GetSlots(t);
for (size_t i = 0; i < t.capacity(); ++i) {
EXPECT_EQ(slots + i != &v1, __asan_address_is_poisoned(slots + i));
}
}
TEST(Sanitizer, PoisoningOnErase) {
IntTable t;
int64_t& v = *t.insert(0).first;
EXPECT_FALSE(__asan_address_is_poisoned(&v));
t.erase(0);
EXPECT_TRUE(__asan_address_is_poisoned(&v));
}
#endif // ABSL_HAVE_ADDRESS_SANITIZER
template <typename T>
class AlignOneTest : public ::testing::Test {};
using AlignOneTestTypes =
::testing::Types<Uint8Table, MinimumAlignmentUint8Table>;
TYPED_TEST_SUITE(AlignOneTest, AlignOneTestTypes);
TYPED_TEST(AlignOneTest, AlignOne) {
// We previously had a bug in which we were copying a control byte over the
// first slot when alignof(value_type) is 1. We test repeated
// insertions/erases and verify that the behavior is correct.
TypeParam t;
std::unordered_set<uint8_t> verifier; // NOLINT
// Do repeated insertions/erases from the table.
for (int64_t i = 0; i < 100000; ++i) {
SCOPED_TRACE(i);
const uint8_t u = (i * -i) & 0xFF;
auto it = t.find(u);
auto verifier_it = verifier.find(u);
if (it == t.end()) {
ASSERT_EQ(verifier_it, verifier.end());
t.insert(u);
verifier.insert(u);
} else {
ASSERT_NE(verifier_it, verifier.end());
t.erase(it);
verifier.erase(verifier_it);
}
}
EXPECT_EQ(t.size(), verifier.size());
for (uint8_t u : t) {
EXPECT_EQ(verifier.count(u), 1);
}
}
TEST(Iterator, InvalidUseCrashesWithSanitizers) {
if (!SwisstableGenerationsEnabled()) GTEST_SKIP() << "Generations disabled.";
if (kMsvc) GTEST_SKIP() << "MSVC doesn't support | in regexp.";
IntTable t;
// Start with 1 element so that `it` is never an end iterator.
t.insert(-1);
for (int i = 0; i < 10; ++i) {
auto it = t.begin();
t.insert(i);
EXPECT_DEATH_IF_SUPPORTED(*it, kInvalidIteratorDeathMessage);
EXPECT_DEATH_IF_SUPPORTED(void(it == t.begin()),
kInvalidIteratorDeathMessage);
}
}
TEST(Iterator, InvalidUseWithReserveCrashesWithSanitizers) {
if (!SwisstableGenerationsEnabled()) GTEST_SKIP() << "Generations disabled.";
if (kMsvc) GTEST_SKIP() << "MSVC doesn't support | in regexp.";
IntTable t;
t.reserve(10);
t.insert(0);
auto it = t.begin();
// Reserved growth can't rehash.
for (int i = 1; i < 10; ++i) {
t.insert(i);
EXPECT_EQ(*it, 0);
}
// ptr will become invalidated on rehash.
const int64_t* ptr = &*it;
(void)ptr;
// erase decreases size but does not decrease reserved growth so the next
// insertion still invalidates iterators.
t.erase(0);
// The first insert after reserved growth is 0 is guaranteed to rehash when
// generations are enabled.
t.insert(10);
EXPECT_DEATH_IF_SUPPORTED(*it, kInvalidIteratorDeathMessage);
EXPECT_DEATH_IF_SUPPORTED(void(it == t.begin()),
kInvalidIteratorDeathMessage);
#ifdef ABSL_HAVE_ADDRESS_SANITIZER
EXPECT_DEATH_IF_SUPPORTED(std::cout << *ptr, "heap-use-after-free");
#endif
}
TEST(Table, ReservedGrowthUpdatesWhenTableDoesntGrow) {
IntTable t;
for (int i = 0; i < 8; ++i) t.insert(i);
// Want to insert twice without invalidating iterators so reserve.
const size_t cap = t.capacity();
t.reserve(t.size() + 2);
// We want to be testing the case in which the reserve doesn't grow the table.
ASSERT_EQ(cap, t.capacity());
auto it = t.find(0);
t.insert(100);
t.insert(200);
// `it` shouldn't have been invalidated.
EXPECT_EQ(*it, 0);
}
TEST(Table, EraseBeginEndResetsReservedGrowth) {
bool frozen = false;
BadHashFreezableIntTable t{FreezableAlloc<int64_t>(&frozen)};
t.reserve(100);
const size_t cap = t.capacity();
frozen = true; // no further allocs allowed
for (int i = 0; i < 10; ++i) {
// Create a long run (hash function returns constant).
for (int j = 0; j < 100; ++j) t.insert(j);
// Erase elements from the middle of the long run, which creates tombstones.
for (int j = 30; j < 60; ++j) t.erase(j);
EXPECT_EQ(t.size(), 70);
EXPECT_EQ(t.capacity(), cap);
ASSERT_EQ(RawHashSetTestOnlyAccess::CountTombstones(t), 30);
t.erase(t.begin(), t.end());
EXPECT_EQ(t.size(), 0);
EXPECT_EQ(t.capacity(), cap);
ASSERT_EQ(RawHashSetTestOnlyAccess::CountTombstones(t), 0);
}
}
TEST(Table, GenerationInfoResetsOnClear) {
if (!SwisstableGenerationsEnabled()) GTEST_SKIP() << "Generations disabled.";
if (kMsvc) GTEST_SKIP() << "MSVC doesn't support | in regexp.";
IntTable t;
for (int i = 0; i < 1000; ++i) t.insert(i);
t.reserve(t.size() + 100);
t.clear();
t.insert(0);
auto it = t.begin();
t.insert(1);
EXPECT_DEATH_IF_SUPPORTED(*it, kInvalidIteratorDeathMessage);
}
TEST(Table, InvalidReferenceUseCrashesWithSanitizers) {
if (!SwisstableGenerationsEnabled()) GTEST_SKIP() << "Generations disabled.";
#ifdef ABSL_HAVE_MEMORY_SANITIZER
GTEST_SKIP() << "MSan fails to detect some of these rehashes.";
#endif
IntTable t;
t.insert(0);
// Rehashing is guaranteed on every insertion while capacity is less than
// RehashProbabilityConstant().
int64_t i = 0;
while (t.capacity() <= RehashProbabilityConstant()) {
// ptr will become invalidated on rehash.
const int64_t* ptr = &*t.begin();
t.insert(++i);
EXPECT_DEATH_IF_SUPPORTED(std::cout << *ptr, "heap-use-after-free") << i;
}
}
TEST(Iterator, InvalidComparisonDifferentTables) {
if (!SwisstableGenerationsEnabled()) GTEST_SKIP() << "Generations disabled.";
IntTable t1, t2;
IntTable::iterator default_constructed_iter;
// We randomly use one of N empty generations for generations from empty
// hashtables. In general, we won't always detect when iterators from
// different empty hashtables are compared, but in this test case, we
// should deterministically detect the error due to our randomness yielding
// consecutive random generations.
EXPECT_DEATH_IF_SUPPORTED(void(t1.end() == t2.end()),
"Invalid iterator comparison.*empty hashtables");
EXPECT_DEATH_IF_SUPPORTED(void(t1.end() == default_constructed_iter),
"Invalid iterator comparison.*default-constructed");
t1.insert(0);
EXPECT_DEATH_IF_SUPPORTED(void(t1.begin() == t2.end()),
"Invalid iterator comparison.*empty hashtable");
EXPECT_DEATH_IF_SUPPORTED(void(t1.begin() == default_constructed_iter),
"Invalid iterator comparison.*default-constructed");
t2.insert(0);
EXPECT_DEATH_IF_SUPPORTED(void(t1.begin() == t2.end()),
"Invalid iterator comparison.*end.. iterator");
EXPECT_DEATH_IF_SUPPORTED(void(t1.begin() == t2.begin()),
"Invalid iterator comparison.*non-end");
}
} // namespace
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl