From 48cd2c3f351ff188bc85684b84a91b6e6d17d896 Mon Sep 17 00:00:00 2001 From: Abseil Team Date: Thu, 27 Sep 2018 12:24:54 -0700 Subject: Export of internal Abseil changes. -- 4eacae3ff1b14b1d309e8092185bc10e8a6203cf by Derek Mauro : Release SwissTable - a fast, efficient, cache-friendly hash table. https://www.youtube.com/watch?v=ncHmEUmJZf4 PiperOrigin-RevId: 214816527 -- df8c3dfab3cfb2f4365909a84d0683b193cfbb11 by Derek Mauro : Internal change PiperOrigin-RevId: 214785288 -- 1eabd5266bbcebc33eecc91e5309b751856a75c8 by Abseil Team : Internal change PiperOrigin-RevId: 214722931 -- 2ebbfac950f83146b46253038e7dd7dcde9f2951 by Derek Mauro : Internal change PiperOrigin-RevId: 214701684 GitOrigin-RevId: 4eacae3ff1b14b1d309e8092185bc10e8a6203cf Change-Id: I9ba64e395b22ad7863213d157b8019b082adc19d --- absl/container/flat_hash_map_test.cc | 241 +++++++++++++++++++++++++++++++++++ 1 file changed, 241 insertions(+) create mode 100644 absl/container/flat_hash_map_test.cc (limited to 'absl/container/flat_hash_map_test.cc') diff --git a/absl/container/flat_hash_map_test.cc b/absl/container/flat_hash_map_test.cc new file mode 100644 index 0000000..10a781f --- /dev/null +++ b/absl/container/flat_hash_map_test.cc @@ -0,0 +1,241 @@ +// 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 +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// 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/flat_hash_map.h" + +#include "absl/container/internal/hash_generator_testing.h" +#include "absl/container/internal/unordered_map_constructor_test.h" +#include "absl/container/internal/unordered_map_lookup_test.h" +#include "absl/container/internal/unordered_map_modifiers_test.h" +#include "absl/types/any.h" + +namespace absl { +namespace container_internal { +namespace { +using ::absl::container_internal::hash_internal::Enum; +using ::absl::container_internal::hash_internal::EnumClass; +using ::testing::_; +using ::testing::Pair; +using ::testing::UnorderedElementsAre; + +template +using Map = + flat_hash_map>; + +static_assert(!std::is_standard_layout(), ""); + +using MapTypes = + ::testing::Types, Map, Map, + Map, Map, + Map>; + +INSTANTIATE_TYPED_TEST_CASE_P(FlatHashMap, ConstructorTest, MapTypes); +INSTANTIATE_TYPED_TEST_CASE_P(FlatHashMap, LookupTest, MapTypes); +INSTANTIATE_TYPED_TEST_CASE_P(FlatHashMap, ModifiersTest, MapTypes); + +TEST(FlatHashMap, StandardLayout) { + struct Int { + explicit Int(size_t value) : value(value) {} + Int() : value(0) { ADD_FAILURE(); } + Int(const Int& other) : value(other.value) { ADD_FAILURE(); } + Int(Int&&) = default; + bool operator==(const Int& other) const { return value == other.value; } + size_t value; + }; + static_assert(std::is_standard_layout(), ""); + + struct Hash { + size_t operator()(const Int& obj) const { return obj.value; } + }; + + // Verify that neither the key nor the value get default-constructed or + // copy-constructed. + { + flat_hash_map m; + m.try_emplace(Int(1), Int(2)); + m.try_emplace(Int(3), Int(4)); + m.erase(Int(1)); + m.rehash(2 * m.bucket_count()); + } + { + flat_hash_map m; + m.try_emplace(Int(1), Int(2)); + m.try_emplace(Int(3), Int(4)); + m.erase(Int(1)); + m.clear(); + } +} + +// gcc becomes unhappy if this is inside the method, so pull it out here. +struct balast {}; + +TEST(FlatHashMap, IteratesMsan) { + // Because SwissTable randomizes on pointer addresses, we keep old tables + // around to ensure we don't reuse old memory. + std::vector> garbage; + for (int i = 0; i < 100; ++i) { + absl::flat_hash_map t; + for (int j = 0; j < 100; ++j) { + t[j]; + for (const auto& p : t) EXPECT_THAT(p, Pair(_, _)); + } + garbage.push_back(std::move(t)); + } +} + +// Demonstration of the "Lazy Key" pattern. This uses heterogenous insert to +// avoid creating expensive key elements when the item is already present in the +// map. +struct LazyInt { + explicit LazyInt(size_t value, int* tracker) + : value(value), tracker(tracker) {} + + explicit operator size_t() const { + ++*tracker; + return value; + } + + size_t value; + int* tracker; +}; + +struct Hash { + using is_transparent = void; + int* tracker; + size_t operator()(size_t obj) const { + ++*tracker; + return obj; + } + size_t operator()(const LazyInt& obj) const { + ++*tracker; + return obj.value; + } +}; + +struct Eq { + using is_transparent = void; + bool operator()(size_t lhs, size_t rhs) const { + return lhs == rhs; + } + bool operator()(size_t lhs, const LazyInt& rhs) const { + return lhs == rhs.value; + } +}; + +TEST(FlatHashMap, LazyKeyPattern) { + // hashes are only guaranteed in opt mode, we use assertions to track internal + // state that can cause extra calls to hash. + int conversions = 0; + int hashes = 0; + flat_hash_map m(0, Hash{&hashes}); + + m[LazyInt(1, &conversions)] = 1; + EXPECT_THAT(m, UnorderedElementsAre(Pair(1, 1))); + EXPECT_EQ(conversions, 1); +#ifdef NDEBUG + EXPECT_EQ(hashes, 1); +#endif + + m[LazyInt(1, &conversions)] = 2; + EXPECT_THAT(m, UnorderedElementsAre(Pair(1, 2))); + EXPECT_EQ(conversions, 1); +#ifdef NDEBUG + EXPECT_EQ(hashes, 2); +#endif + + m.try_emplace(LazyInt(2, &conversions), 3); + EXPECT_THAT(m, UnorderedElementsAre(Pair(1, 2), Pair(2, 3))); + EXPECT_EQ(conversions, 2); +#ifdef NDEBUG + EXPECT_EQ(hashes, 3); +#endif + + m.try_emplace(LazyInt(2, &conversions), 4); + EXPECT_THAT(m, UnorderedElementsAre(Pair(1, 2), Pair(2, 3))); + EXPECT_EQ(conversions, 2); +#ifdef NDEBUG + EXPECT_EQ(hashes, 4); +#endif +} + +TEST(FlatHashMap, BitfieldArgument) { + union { + int n : 1; + }; + n = 0; + flat_hash_map m; + m.erase(n); + m.count(n); + m.prefetch(n); + m.find(n); + m.contains(n); + m.equal_range(n); + m.insert_or_assign(n, n); + m.insert_or_assign(m.end(), n, n); + m.try_emplace(n); + m.try_emplace(m.end(), n); + m.at(n); + m[n]; +} + +TEST(FlatHashMap, MergeExtractInsert) { + // We can't test mutable keys, or non-copyable keys with flat_hash_map. + // Test that the nodes have the proper API. + absl::flat_hash_map m = {{1, 7}, {2, 9}}; + auto node = m.extract(1); + EXPECT_TRUE(node); + EXPECT_EQ(node.key(), 1); + EXPECT_EQ(node.mapped(), 7); + EXPECT_THAT(m, UnorderedElementsAre(Pair(2, 9))); + + node.mapped() = 17; + m.insert(std::move(node)); + EXPECT_THAT(m, UnorderedElementsAre(Pair(1, 17), Pair(2, 9))); +} +#if !defined(__ANDROID__) && !defined(__APPLE__) && !defined(__EMSCRIPTEN__) +TEST(FlatHashMap, Any) { + absl::flat_hash_map m; + m.emplace(1, 7); + auto it = m.find(1); + ASSERT_NE(it, m.end()); + EXPECT_EQ(7, absl::any_cast(it->second)); + + m.emplace(std::piecewise_construct, std::make_tuple(2), std::make_tuple(8)); + it = m.find(2); + ASSERT_NE(it, m.end()); + EXPECT_EQ(8, absl::any_cast(it->second)); + + m.emplace(std::piecewise_construct, std::make_tuple(3), + std::make_tuple(absl::any(9))); + it = m.find(3); + ASSERT_NE(it, m.end()); + EXPECT_EQ(9, absl::any_cast(it->second)); + + struct H { + size_t operator()(const absl::any&) const { return 0; } + }; + struct E { + bool operator()(const absl::any&, const absl::any&) const { return true; } + }; + absl::flat_hash_map m2; + m2.emplace(1, 7); + auto it2 = m2.find(1); + ASSERT_NE(it2, m2.end()); + EXPECT_EQ(7, it2->second); +} +#endif // __ANDROID__ + +} // namespace +} // namespace container_internal +} // namespace absl -- cgit v1.2.3