diff options
Diffstat (limited to 'abseil-cpp/absl/strings/cord_test.cc')
| -rw-r--r-- | abseil-cpp/absl/strings/cord_test.cc | 1992 |
1 files changed, 1791 insertions, 201 deletions
diff --git a/abseil-cpp/absl/strings/cord_test.cc b/abseil-cpp/absl/strings/cord_test.cc index 4443c82..36e397e 100644 --- a/abseil-cpp/absl/strings/cord_test.cc +++ b/abseil-cpp/absl/strings/cord_test.cc @@ -1,3 +1,17 @@ +// Copyright 2020 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 +// +// https://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/strings/cord.h" #include <algorithm> @@ -14,19 +28,40 @@ #include "gmock/gmock.h" #include "gtest/gtest.h" -#include "absl/base/casts.h" #include "absl/base/config.h" #include "absl/base/internal/endian.h" -#include "absl/base/internal/raw_logging.h" #include "absl/base/macros.h" #include "absl/container/fixed_array.h" +#include "absl/hash/hash.h" +#include "absl/log/check.h" +#include "absl/log/log.h" +#include "absl/random/random.h" #include "absl/strings/cord_test_helpers.h" +#include "absl/strings/cordz_test_helpers.h" +#include "absl/strings/match.h" #include "absl/strings/str_cat.h" #include "absl/strings/str_format.h" #include "absl/strings/string_view.h" +// convenience local constants +static constexpr auto FLAT = absl::cord_internal::FLAT; +static constexpr auto MAX_FLAT_TAG = absl::cord_internal::MAX_FLAT_TAG; + typedef std::mt19937_64 RandomEngine; +using absl::cord_internal::CordRep; +using absl::cord_internal::CordRepBtree; +using absl::cord_internal::CordRepConcat; +using absl::cord_internal::CordRepCrc; +using absl::cord_internal::CordRepExternal; +using absl::cord_internal::CordRepFlat; +using absl::cord_internal::CordRepSubstring; +using absl::cord_internal::CordzUpdateTracker; +using absl::cord_internal::kFlatOverhead; +using absl::cord_internal::kMaxFlatLength; +using ::testing::ElementsAre; +using ::testing::Le; + static std::string RandomLowercaseString(RandomEngine* rng); static std::string RandomLowercaseString(RandomEngine* rng, size_t length); @@ -167,12 +202,130 @@ class CordTestPeer { const Cord& c, absl::FunctionRef<void(absl::string_view)> callback) { c.ForEachChunk(callback); } + + static bool IsTree(const Cord& c) { return c.contents_.is_tree(); } + static CordRep* Tree(const Cord& c) { return c.contents_.tree(); } + + static cord_internal::CordzInfo* GetCordzInfo(const Cord& c) { + return c.contents_.cordz_info(); + } + + static Cord MakeSubstring(Cord src, size_t offset, size_t length) { + CHECK(src.contents_.is_tree()) << "Can not be inlined"; + CHECK(!src.ExpectedChecksum().has_value()) << "Can not be hardened"; + Cord cord; + auto* tree = cord_internal::SkipCrcNode(src.contents_.tree()); + auto* rep = CordRepSubstring::Create(CordRep::Ref(tree), offset, length); + cord.contents_.EmplaceTree(rep, CordzUpdateTracker::kSubCord); + return cord; + } }; ABSL_NAMESPACE_END } // namespace absl -TEST(Cord, AllFlatSizes) { +// The CordTest fixture runs all tests with and without Cord Btree enabled, +// and with our without expected CRCs being set on the subject Cords. +class CordTest : public testing::TestWithParam<int> { + public: + // Returns true if test is running with btree enabled. + bool UseCrc() const { return GetParam() == 2 || GetParam() == 3; } + void MaybeHarden(absl::Cord& c) { + if (UseCrc()) { + c.SetExpectedChecksum(1); + } + } + absl::Cord MaybeHardened(absl::Cord c) { + MaybeHarden(c); + return c; + } + + // Returns human readable string representation of the test parameter. + static std::string ToString(testing::TestParamInfo<int> param) { + switch (param.param) { + case 0: + return "Btree"; + case 1: + return "BtreeHardened"; + default: + assert(false); + return "???"; + } + } +}; + +INSTANTIATE_TEST_SUITE_P(WithParam, CordTest, testing::Values(0, 1), + CordTest::ToString); + +TEST(CordRepFlat, AllFlatCapacities) { + // Explicitly and redundantly assert built-in min/max limits + static_assert(absl::cord_internal::kFlatOverhead < 32, ""); + static_assert(absl::cord_internal::kMinFlatSize == 32, ""); + static_assert(absl::cord_internal::kMaxLargeFlatSize == 256 << 10, ""); + EXPECT_EQ(absl::cord_internal::TagToAllocatedSize(FLAT), 32); + EXPECT_EQ(absl::cord_internal::TagToAllocatedSize(MAX_FLAT_TAG), 256 << 10); + + // Verify all tags to map perfectly back and forth, and + // that sizes are monotonically increasing. + size_t last_size = 0; + for (int tag = FLAT; tag <= MAX_FLAT_TAG; ++tag) { + size_t size = absl::cord_internal::TagToAllocatedSize(tag); + ASSERT_GT(size, last_size); + ASSERT_EQ(absl::cord_internal::TagToAllocatedSize(tag), size); + last_size = size; + } + + // All flat size from 32 - 512 are 8 byte granularity + for (size_t size = 32; size <= 512; size += 8) { + ASSERT_EQ(absl::cord_internal::RoundUpForTag(size), size); + uint8_t tag = absl::cord_internal::AllocatedSizeToTag(size); + ASSERT_EQ(absl::cord_internal::TagToAllocatedSize(tag), size); + } + + // All flat sizes from 512 - 8192 are 64 byte granularity + for (size_t size = 512; size <= 8192; size += 64) { + ASSERT_EQ(absl::cord_internal::RoundUpForTag(size), size); + uint8_t tag = absl::cord_internal::AllocatedSizeToTag(size); + ASSERT_EQ(absl::cord_internal::TagToAllocatedSize(tag), size); + } + + // All flat sizes from 8KB to 256KB are 4KB granularity + for (size_t size = 8192; size <= 256 * 1024; size += 4 * 1024) { + ASSERT_EQ(absl::cord_internal::RoundUpForTag(size), size); + uint8_t tag = absl::cord_internal::AllocatedSizeToTag(size); + ASSERT_EQ(absl::cord_internal::TagToAllocatedSize(tag), size); + } +} + +TEST(CordRepFlat, MaxFlatSize) { + CordRepFlat* flat = CordRepFlat::New(kMaxFlatLength); + EXPECT_EQ(flat->Capacity(), kMaxFlatLength); + CordRep::Unref(flat); + + flat = CordRepFlat::New(kMaxFlatLength * 4); + EXPECT_EQ(flat->Capacity(), kMaxFlatLength); + CordRep::Unref(flat); +} + +TEST(CordRepFlat, MaxLargeFlatSize) { + const size_t size = 256 * 1024 - kFlatOverhead; + CordRepFlat* flat = CordRepFlat::New(CordRepFlat::Large(), size); + EXPECT_GE(flat->Capacity(), size); + CordRep::Unref(flat); +} + +TEST(CordRepFlat, AllFlatSizes) { + const size_t kMaxSize = 256 * 1024; + for (size_t size = 32; size <= kMaxSize; size *=2) { + const size_t length = size - kFlatOverhead - 1; + CordRepFlat* flat = CordRepFlat::New(CordRepFlat::Large(), length); + EXPECT_GE(flat->Capacity(), length); + memset(flat->Data(), 0xCD, flat->Capacity()); + CordRep::Unref(flat); + } +} + +TEST_P(CordTest, AllFlatSizes) { using absl::strings_internal::CordTestAccess; for (size_t s = 0; s < CordTestAccess::MaxFlatLength(); s++) { @@ -183,6 +336,7 @@ TEST(Cord, AllFlatSizes) { } absl::Cord dst(src); + MaybeHarden(dst); EXPECT_EQ(std::string(dst), src) << s; } } @@ -190,7 +344,7 @@ TEST(Cord, AllFlatSizes) { // We create a Cord at least 128GB in size using the fact that Cords can // internally reference-count; thus the Cord is enormous without actually // consuming very much memory. -TEST(GigabyteCord, FromExternal) { +TEST_P(CordTest, GigabyteCordFromExternal) { const size_t one_gig = 1024U * 1024U * 1024U; size_t max_size = 2 * one_gig; if (sizeof(max_size) > 4) max_size = 128 * one_gig; @@ -207,7 +361,6 @@ TEST(GigabyteCord, FromExternal) { // caused crashes in production. We grow exponentially so that the code will // execute in a reasonable amount of time. absl::Cord c; - ABSL_RAW_LOG(INFO, "Made a Cord with %zu bytes!", c.size()); c.Append(from); while (c.size() < max_size) { c.Append(c); @@ -215,12 +368,13 @@ TEST(GigabyteCord, FromExternal) { c.Append(from); c.Append(from); c.Append(from); + MaybeHarden(c); } for (int i = 0; i < 1024; ++i) { c.Append(from); } - ABSL_RAW_LOG(INFO, "Made a Cord with %zu bytes!", c.size()); + LOG(INFO) << "Made a Cord with " << c.size() << " bytes!"; // Note: on a 32-bit build, this comes out to 2,818,048,000 bytes. // Note: on a 64-bit build, this comes out to 171,932,385,280 bytes. } @@ -240,9 +394,11 @@ static absl::Cord MakeExternalCord(int size) { extern bool my_unique_true_boolean; bool my_unique_true_boolean = true; -TEST(Cord, Assignment) { +TEST_P(CordTest, Assignment) { absl::Cord x(absl::string_view("hi there")); absl::Cord y(x); + MaybeHarden(y); + ASSERT_EQ(x.ExpectedChecksum(), absl::nullopt); ASSERT_EQ(std::string(x), "hi there"); ASSERT_EQ(std::string(y), "hi there"); ASSERT_TRUE(x == y); @@ -294,8 +450,9 @@ TEST(Cord, Assignment) { } } -TEST(Cord, StartsEndsWith) { +TEST_P(CordTest, StartsEndsWith) { absl::Cord x(absl::string_view("abcde")); + MaybeHarden(x); absl::Cord empty(""); ASSERT_TRUE(x.StartsWith(absl::Cord("abcde"))); @@ -327,13 +484,14 @@ TEST(Cord, StartsEndsWith) { ASSERT_TRUE(!empty.EndsWith("xyz")); } -TEST(Cord, Subcord) { - RandomEngine rng(testing::GTEST_FLAG(random_seed)); +TEST_P(CordTest, Subcord) { + RandomEngine rng(GTEST_FLAG_GET(random_seed)); const std::string s = RandomLowercaseString(&rng, 1024); absl::Cord a; AppendWithFragments(s, &rng, &a); - ASSERT_EQ(s.size(), a.size()); + MaybeHarden(a); + ASSERT_EQ(s, std::string(a)); // Check subcords of a, from a variety of interesting points. std::set<size_t> positions; @@ -351,9 +509,12 @@ TEST(Cord, Subcord) { for (size_t end_pos : positions) { if (end_pos < pos || end_pos > a.size()) continue; absl::Cord sa = a.Subcord(pos, end_pos - pos); - EXPECT_EQ(absl::string_view(s).substr(pos, end_pos - pos), + ASSERT_EQ(absl::string_view(s).substr(pos, end_pos - pos), std::string(sa)) << a; + if (pos != 0 || end_pos != a.size()) { + ASSERT_EQ(sa.ExpectedChecksum(), absl::nullopt); + } } } @@ -363,7 +524,7 @@ TEST(Cord, Subcord) { for (size_t pos = 0; pos <= sh.size(); ++pos) { for (size_t n = 0; n <= sh.size() - pos; ++n) { absl::Cord sc = c.Subcord(pos, n); - EXPECT_EQ(sh.substr(pos, n), std::string(sc)) << c; + ASSERT_EQ(sh.substr(pos, n), std::string(sc)) << c; } } @@ -373,7 +534,7 @@ TEST(Cord, Subcord) { while (sa.size() > 1) { sa = sa.Subcord(1, sa.size() - 2); ss = ss.substr(1, ss.size() - 2); - EXPECT_EQ(ss, std::string(sa)) << a; + ASSERT_EQ(ss, std::string(sa)) << a; if (HasFailure()) break; // halt cascade } @@ -388,15 +549,24 @@ TEST(Cord, Subcord) { EXPECT_TRUE(sa.empty()); } -TEST(Cord, Swap) { +TEST_P(CordTest, Swap) { absl::string_view a("Dexter"); absl::string_view b("Mandark"); absl::Cord x(a); absl::Cord y(b); + MaybeHarden(x); swap(x, y); + if (UseCrc()) { + ASSERT_EQ(x.ExpectedChecksum(), absl::nullopt); + ASSERT_EQ(y.ExpectedChecksum(), 1); + } ASSERT_EQ(x, absl::Cord(b)); ASSERT_EQ(y, absl::Cord(a)); x.swap(y); + if (UseCrc()) { + ASSERT_EQ(x.ExpectedChecksum(), 1); + ASSERT_EQ(y.ExpectedChecksum(), absl::nullopt); + } ASSERT_EQ(x, absl::Cord(a)); ASSERT_EQ(y, absl::Cord(b)); } @@ -420,56 +590,394 @@ static void VerifyCopyToString(const absl::Cord& cord) { } } -TEST(Cord, CopyToString) { - VerifyCopyToString(absl::Cord()); - VerifyCopyToString(absl::Cord("small cord")); - VerifyCopyToString( +TEST_P(CordTest, CopyToString) { + VerifyCopyToString(absl::Cord()); // empty cords cannot carry CRCs + VerifyCopyToString(MaybeHardened(absl::Cord("small cord"))); + VerifyCopyToString(MaybeHardened( absl::MakeFragmentedCord({"fragmented ", "cord ", "to ", "test ", - "copying ", "to ", "a ", "string."})); + "copying ", "to ", "a ", "string."}))); +} + +TEST_P(CordTest, AppendEmptyBuffer) { + absl::Cord cord; + cord.Append(absl::CordBuffer()); + cord.Append(absl::CordBuffer::CreateWithDefaultLimit(2000)); +} + +TEST_P(CordTest, AppendEmptyBufferToFlat) { + absl::Cord cord(std::string(2000, 'x')); + cord.Append(absl::CordBuffer()); + cord.Append(absl::CordBuffer::CreateWithDefaultLimit(2000)); +} + +TEST_P(CordTest, AppendEmptyBufferToTree) { + absl::Cord cord(std::string(2000, 'x')); + cord.Append(std::string(2000, 'y')); + cord.Append(absl::CordBuffer()); + cord.Append(absl::CordBuffer::CreateWithDefaultLimit(2000)); +} + +TEST_P(CordTest, AppendSmallBuffer) { + absl::Cord cord; + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(3); + ASSERT_THAT(buffer.capacity(), Le(15)); + memcpy(buffer.data(), "Abc", 3); + buffer.SetLength(3); + cord.Append(std::move(buffer)); + EXPECT_EQ(buffer.length(), 0); // NOLINT + EXPECT_GT(buffer.capacity(), 0); // NOLINT + + buffer = absl::CordBuffer::CreateWithDefaultLimit(3); + memcpy(buffer.data(), "defgh", 5); + buffer.SetLength(5); + cord.Append(std::move(buffer)); + EXPECT_EQ(buffer.length(), 0); // NOLINT + EXPECT_GT(buffer.capacity(), 0); // NOLINT + + EXPECT_THAT(cord.Chunks(), ElementsAre("Abcdefgh")); +} + +TEST_P(CordTest, AppendAndPrependBufferArePrecise) { + // Create a cord large enough to force 40KB flats. + std::string test_data(absl::cord_internal::kMaxFlatLength * 10, 'x'); + absl::Cord cord1(test_data); + absl::Cord cord2(test_data); + const size_t size1 = cord1.EstimatedMemoryUsage(); + const size_t size2 = cord2.EstimatedMemoryUsage(); + + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(3); + memcpy(buffer.data(), "Abc", 3); + buffer.SetLength(3); + cord1.Append(std::move(buffer)); + + buffer = absl::CordBuffer::CreateWithDefaultLimit(3); + memcpy(buffer.data(), "Abc", 3); + buffer.SetLength(3); + cord2.Prepend(std::move(buffer)); + +#ifndef NDEBUG + // Allow 32 bytes new CordRepFlat, and 128 bytes for 'glue nodes' + constexpr size_t kMaxDelta = 128 + 32; +#else + // Allow 256 bytes extra for 'allocation debug overhead' + constexpr size_t kMaxDelta = 128 + 32 + 256; +#endif + + EXPECT_LE(cord1.EstimatedMemoryUsage() - size1, kMaxDelta); + EXPECT_LE(cord2.EstimatedMemoryUsage() - size2, kMaxDelta); + + EXPECT_EQ(cord1, absl::StrCat(test_data, "Abc")); + EXPECT_EQ(cord2, absl::StrCat("Abc", test_data)); +} + +TEST_P(CordTest, PrependSmallBuffer) { + absl::Cord cord; + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(3); + ASSERT_THAT(buffer.capacity(), Le(15)); + memcpy(buffer.data(), "Abc", 3); + buffer.SetLength(3); + cord.Prepend(std::move(buffer)); + EXPECT_EQ(buffer.length(), 0); // NOLINT + EXPECT_GT(buffer.capacity(), 0); // NOLINT + + buffer = absl::CordBuffer::CreateWithDefaultLimit(3); + memcpy(buffer.data(), "defgh", 5); + buffer.SetLength(5); + cord.Prepend(std::move(buffer)); + EXPECT_EQ(buffer.length(), 0); // NOLINT + EXPECT_GT(buffer.capacity(), 0); // NOLINT + + EXPECT_THAT(cord.Chunks(), ElementsAre("defghAbc")); +} + +TEST_P(CordTest, AppendLargeBuffer) { + absl::Cord cord; + + std::string s1(700, '1'); + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(s1.size()); + memcpy(buffer.data(), s1.data(), s1.size()); + buffer.SetLength(s1.size()); + cord.Append(std::move(buffer)); + EXPECT_EQ(buffer.length(), 0); // NOLINT + EXPECT_GT(buffer.capacity(), 0); // NOLINT + + std::string s2(1000, '2'); + buffer = absl::CordBuffer::CreateWithDefaultLimit(s2.size()); + memcpy(buffer.data(), s2.data(), s2.size()); + buffer.SetLength(s2.size()); + cord.Append(std::move(buffer)); + EXPECT_EQ(buffer.length(), 0); // NOLINT + EXPECT_GT(buffer.capacity(), 0); // NOLINT + + EXPECT_THAT(cord.Chunks(), ElementsAre(s1, s2)); +} + +TEST_P(CordTest, PrependLargeBuffer) { + absl::Cord cord; + + std::string s1(700, '1'); + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(s1.size()); + memcpy(buffer.data(), s1.data(), s1.size()); + buffer.SetLength(s1.size()); + cord.Prepend(std::move(buffer)); + EXPECT_EQ(buffer.length(), 0); // NOLINT + EXPECT_GT(buffer.capacity(), 0); // NOLINT + + std::string s2(1000, '2'); + buffer = absl::CordBuffer::CreateWithDefaultLimit(s2.size()); + memcpy(buffer.data(), s2.data(), s2.size()); + buffer.SetLength(s2.size()); + cord.Prepend(std::move(buffer)); + EXPECT_EQ(buffer.length(), 0); // NOLINT + EXPECT_GT(buffer.capacity(), 0); // NOLINT + + EXPECT_THAT(cord.Chunks(), ElementsAre(s2, s1)); +} + +class CordAppendBufferTest : public testing::TestWithParam<bool> { + public: + size_t is_default() const { return GetParam(); } + + // Returns human readable string representation of the test parameter. + static std::string ToString(testing::TestParamInfo<bool> param) { + return param.param ? "DefaultLimit" : "CustomLimit"; + } + + size_t limit() const { + return is_default() ? absl::CordBuffer::kDefaultLimit + : absl::CordBuffer::kCustomLimit; + } + + size_t maximum_payload() const { + return is_default() ? absl::CordBuffer::MaximumPayload() + : absl::CordBuffer::MaximumPayload(limit()); + } + + absl::CordBuffer GetAppendBuffer(absl::Cord& cord, size_t capacity, + size_t min_capacity = 16) { + return is_default() + ? cord.GetAppendBuffer(capacity, min_capacity) + : cord.GetCustomAppendBuffer(limit(), capacity, min_capacity); + } +}; + +INSTANTIATE_TEST_SUITE_P(WithParam, CordAppendBufferTest, testing::Bool(), + CordAppendBufferTest::ToString); + +TEST_P(CordAppendBufferTest, GetAppendBufferOnEmptyCord) { + absl::Cord cord; + absl::CordBuffer buffer = GetAppendBuffer(cord, 1000); + EXPECT_GE(buffer.capacity(), 1000); + EXPECT_EQ(buffer.length(), 0); +} + +TEST_P(CordAppendBufferTest, GetAppendBufferOnInlinedCord) { + static constexpr int kInlinedSize = sizeof(absl::CordBuffer) - 1; + for (int size : {6, kInlinedSize - 3, kInlinedSize - 2, 1000}) { + absl::Cord cord("Abc"); + absl::CordBuffer buffer = GetAppendBuffer(cord, size, 1); + EXPECT_GE(buffer.capacity(), 3 + size); + EXPECT_EQ(buffer.length(), 3); + EXPECT_EQ(absl::string_view(buffer.data(), buffer.length()), "Abc"); + EXPECT_TRUE(cord.empty()); + } +} + +TEST_P(CordAppendBufferTest, GetAppendBufferOnInlinedCordCapacityCloseToMax) { + // Cover the use case where we have a non empty inlined cord with some size + // 'n', and ask for something like 'uint64_max - k', assuming internal logic + // could overflow on 'uint64_max - k + size', and return a valid, but + // inefficiently smaller buffer if it would provide is the max allowed size. + for (size_t dist_from_max = 0; dist_from_max <= 4; ++dist_from_max) { + absl::Cord cord("Abc"); + size_t size = std::numeric_limits<size_t>::max() - dist_from_max; + absl::CordBuffer buffer = GetAppendBuffer(cord, size, 1); + EXPECT_GE(buffer.capacity(), maximum_payload()); + EXPECT_EQ(buffer.length(), 3); + EXPECT_EQ(absl::string_view(buffer.data(), buffer.length()), "Abc"); + EXPECT_TRUE(cord.empty()); + } +} + +TEST_P(CordAppendBufferTest, GetAppendBufferOnFlat) { + // Create a cord with a single flat and extra capacity + absl::Cord cord; + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(500); + const size_t expected_capacity = buffer.capacity(); + buffer.SetLength(3); + memcpy(buffer.data(), "Abc", 3); + cord.Append(std::move(buffer)); + + buffer = GetAppendBuffer(cord, 6); + EXPECT_EQ(buffer.capacity(), expected_capacity); + EXPECT_EQ(buffer.length(), 3); + EXPECT_EQ(absl::string_view(buffer.data(), buffer.length()), "Abc"); + EXPECT_TRUE(cord.empty()); } -TEST(TryFlat, Empty) { +TEST_P(CordAppendBufferTest, GetAppendBufferOnFlatWithoutMinCapacity) { + // Create a cord with a single flat and extra capacity + absl::Cord cord; + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(500); + buffer.SetLength(30); + memset(buffer.data(), 'x', 30); + cord.Append(std::move(buffer)); + + buffer = GetAppendBuffer(cord, 1000, 900); + EXPECT_GE(buffer.capacity(), 1000); + EXPECT_EQ(buffer.length(), 0); + EXPECT_EQ(cord, std::string(30, 'x')); +} + +TEST_P(CordAppendBufferTest, GetAppendBufferOnTree) { + RandomEngine rng; + for (int num_flats : {2, 3, 100}) { + // Create a cord with `num_flats` flats and extra capacity + absl::Cord cord; + std::string prefix; + std::string last; + for (int i = 0; i < num_flats - 1; ++i) { + prefix += last; + last = RandomLowercaseString(&rng, 10); + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(500); + buffer.SetLength(10); + memcpy(buffer.data(), last.data(), 10); + cord.Append(std::move(buffer)); + } + absl::CordBuffer buffer = GetAppendBuffer(cord, 6); + EXPECT_GE(buffer.capacity(), 500); + EXPECT_EQ(buffer.length(), 10); + EXPECT_EQ(absl::string_view(buffer.data(), buffer.length()), last); + EXPECT_EQ(cord, prefix); + } +} + +TEST_P(CordAppendBufferTest, GetAppendBufferOnTreeWithoutMinCapacity) { + absl::Cord cord; + for (int i = 0; i < 2; ++i) { + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(500); + buffer.SetLength(3); + memcpy(buffer.data(), i ? "def" : "Abc", 3); + cord.Append(std::move(buffer)); + } + absl::CordBuffer buffer = GetAppendBuffer(cord, 1000, 900); + EXPECT_GE(buffer.capacity(), 1000); + EXPECT_EQ(buffer.length(), 0); + EXPECT_EQ(cord, "Abcdef"); +} + +TEST_P(CordAppendBufferTest, GetAppendBufferOnSubstring) { + // Create a large cord with a single flat and some extra capacity + absl::Cord cord; + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(500); + buffer.SetLength(450); + memset(buffer.data(), 'x', 450); + cord.Append(std::move(buffer)); + cord.RemovePrefix(1); + + // Deny on substring + buffer = GetAppendBuffer(cord, 6); + EXPECT_EQ(buffer.length(), 0); + EXPECT_EQ(cord, std::string(449, 'x')); +} + +TEST_P(CordAppendBufferTest, GetAppendBufferOnSharedCord) { + // Create a shared cord with a single flat and extra capacity + absl::Cord cord; + absl::CordBuffer buffer = absl::CordBuffer::CreateWithDefaultLimit(500); + buffer.SetLength(3); + memcpy(buffer.data(), "Abc", 3); + cord.Append(std::move(buffer)); + absl::Cord shared_cord = cord; + + // Deny on flat + buffer = GetAppendBuffer(cord, 6); + EXPECT_EQ(buffer.length(), 0); + EXPECT_EQ(cord, "Abc"); + + buffer = absl::CordBuffer::CreateWithDefaultLimit(500); + buffer.SetLength(3); + memcpy(buffer.data(), "def", 3); + cord.Append(std::move(buffer)); + shared_cord = cord; + + // Deny on tree + buffer = GetAppendBuffer(cord, 6); + EXPECT_EQ(buffer.length(), 0); + EXPECT_EQ(cord, "Abcdef"); +} + +TEST_P(CordTest, TryFlatEmpty) { absl::Cord c; EXPECT_EQ(c.TryFlat(), ""); } -TEST(TryFlat, Flat) { +TEST_P(CordTest, TryFlatFlat) { absl::Cord c("hello"); + MaybeHarden(c); EXPECT_EQ(c.TryFlat(), "hello"); } -TEST(TryFlat, SubstrInlined) { +TEST_P(CordTest, TryFlatSubstrInlined) { absl::Cord c("hello"); c.RemovePrefix(1); + MaybeHarden(c); EXPECT_EQ(c.TryFlat(), "ello"); } -TEST(TryFlat, SubstrFlat) { +TEST_P(CordTest, TryFlatSubstrFlat) { absl::Cord c("longer than 15 bytes"); - c.RemovePrefix(1); - EXPECT_EQ(c.TryFlat(), "onger than 15 bytes"); + absl::Cord sub = absl::CordTestPeer::MakeSubstring(c, 1, c.size() - 1); + MaybeHarden(sub); + EXPECT_EQ(sub.TryFlat(), "onger than 15 bytes"); } -TEST(TryFlat, Concat) { +TEST_P(CordTest, TryFlatConcat) { absl::Cord c = absl::MakeFragmentedCord({"hel", "lo"}); + MaybeHarden(c); EXPECT_EQ(c.TryFlat(), absl::nullopt); } -TEST(TryFlat, External) { +TEST_P(CordTest, TryFlatExternal) { absl::Cord c = absl::MakeCordFromExternal("hell", [](absl::string_view) {}); + MaybeHarden(c); EXPECT_EQ(c.TryFlat(), "hell"); } -TEST(TryFlat, SubstrExternal) { +TEST_P(CordTest, TryFlatSubstrExternal) { absl::Cord c = absl::MakeCordFromExternal("hell", [](absl::string_view) {}); - c.RemovePrefix(1); - EXPECT_EQ(c.TryFlat(), "ell"); -} - -TEST(TryFlat, SubstrConcat) { - absl::Cord c = absl::MakeFragmentedCord({"hello", " world"}); - c.RemovePrefix(1); - EXPECT_EQ(c.TryFlat(), absl::nullopt); + absl::Cord sub = absl::CordTestPeer::MakeSubstring(c, 1, c.size() - 1); + MaybeHarden(sub); + EXPECT_EQ(sub.TryFlat(), "ell"); +} + +TEST_P(CordTest, TryFlatCommonlyAssumedInvariants) { + // The behavior tested below is not part of the API contract of Cord, but it's + // something we intend to be true in our current implementation. This test + // exists to detect and prevent accidental breakage of the implementation. + absl::string_view fragments[] = {"A fragmented test", + " cord", + " to test subcords", + " of ", + "a", + " cord for", + " each chunk " + "returned by the ", + "iterator"}; + absl::Cord c = absl::MakeFragmentedCord(fragments); + MaybeHarden(c); + int fragment = 0; + int offset = 0; + absl::Cord::CharIterator itc = c.char_begin(); + for (absl::string_view sv : c.Chunks()) { + absl::string_view expected = fragments[fragment]; + absl::Cord subcord1 = c.Subcord(offset, sv.length()); + absl::Cord subcord2 = absl::Cord::AdvanceAndRead(&itc, sv.size()); + EXPECT_EQ(subcord1.TryFlat(), expected); + EXPECT_EQ(subcord2.TryFlat(), expected); + ++fragment; + offset += sv.length(); + } } static bool IsFlat(const absl::Cord& c) { @@ -500,15 +1008,17 @@ static void VerifyFlatten(absl::Cord c) { EXPECT_TRUE(IsFlat(c)); } -TEST(Cord, Flatten) { +TEST_P(CordTest, Flatten) { VerifyFlatten(absl::Cord()); - VerifyFlatten(absl::Cord("small cord")); - VerifyFlatten(absl::Cord("larger than small buffer optimization")); - VerifyFlatten(absl::MakeFragmentedCord({"small ", "fragmented ", "cord"})); + VerifyFlatten(MaybeHardened(absl::Cord("small cord"))); + VerifyFlatten( + MaybeHardened(absl::Cord("larger than small buffer optimization"))); + VerifyFlatten(MaybeHardened( + absl::MakeFragmentedCord({"small ", "fragmented ", "cord"}))); // Test with a cord that is longer than the largest flat buffer - RandomEngine rng(testing::GTEST_FLAG(random_seed)); - VerifyFlatten(absl::Cord(RandomLowercaseString(&rng, 8192))); + RandomEngine rng(GTEST_FLAG_GET(random_seed)); + VerifyFlatten(MaybeHardened(absl::Cord(RandomLowercaseString(&rng, 8192)))); } // Test data @@ -554,7 +1064,7 @@ class TestData { }; } // namespace -TEST(Cord, MultipleLengths) { +TEST_P(CordTest, MultipleLengths) { TestData d; for (size_t i = 0; i < d.size(); i++) { std::string a = d.data(i); @@ -562,22 +1072,26 @@ TEST(Cord, MultipleLengths) { { // Construct from Cord absl::Cord tmp(a); absl::Cord x(tmp); + MaybeHarden(x); EXPECT_EQ(a, std::string(x)) << "'" << a << "'"; } { // Construct from absl::string_view absl::Cord x(a); + MaybeHarden(x); EXPECT_EQ(a, std::string(x)) << "'" << a << "'"; } { // Append cord to self absl::Cord self(a); + MaybeHarden(self); self.Append(self); EXPECT_EQ(a + a, std::string(self)) << "'" << a << "' + '" << a << "'"; } { // Prepend cord to self absl::Cord self(a); + MaybeHarden(self); self.Prepend(self); EXPECT_EQ(a + a, std::string(self)) << "'" << a << "' + '" << a << "'"; } @@ -589,12 +1103,14 @@ TEST(Cord, MultipleLengths) { { // CopyFrom Cord absl::Cord x(a); absl::Cord y(b); + MaybeHarden(x); x = y; EXPECT_EQ(b, std::string(x)) << "'" << a << "' + '" << b << "'"; } { // CopyFrom absl::string_view absl::Cord x(a); + MaybeHarden(x); x = b; EXPECT_EQ(b, std::string(x)) << "'" << a << "' + '" << b << "'"; } @@ -602,12 +1118,14 @@ TEST(Cord, MultipleLengths) { { // Cord::Append(Cord) absl::Cord x(a); absl::Cord y(b); + MaybeHarden(x); x.Append(y); EXPECT_EQ(a + b, std::string(x)) << "'" << a << "' + '" << b << "'"; } { // Cord::Append(absl::string_view) absl::Cord x(a); + MaybeHarden(x); x.Append(b); EXPECT_EQ(a + b, std::string(x)) << "'" << a << "' + '" << b << "'"; } @@ -615,12 +1133,14 @@ TEST(Cord, MultipleLengths) { { // Cord::Prepend(Cord) absl::Cord x(a); absl::Cord y(b); + MaybeHarden(x); x.Prepend(y); EXPECT_EQ(b + a, std::string(x)) << "'" << b << "' + '" << a << "'"; } { // Cord::Prepend(absl::string_view) absl::Cord x(a); + MaybeHarden(x); x.Prepend(b); EXPECT_EQ(b + a, std::string(x)) << "'" << b << "' + '" << a << "'"; } @@ -630,25 +1150,29 @@ TEST(Cord, MultipleLengths) { namespace { -TEST(Cord, RemoveSuffixWithExternalOrSubstring) { +TEST_P(CordTest, RemoveSuffixWithExternalOrSubstring) { absl::Cord cord = absl::MakeCordFromExternal( "foo bar baz", [](absl::string_view s) { DoNothing(s, nullptr); }); - EXPECT_EQ("foo bar baz", std::string(cord)); + MaybeHarden(cord); + // This RemoveSuffix() will wrap the EXTERNAL node in a SUBSTRING node. cord.RemoveSuffix(4); EXPECT_EQ("foo bar", std::string(cord)); + MaybeHarden(cord); + // This RemoveSuffix() will adjust the SUBSTRING node in-place. cord.RemoveSuffix(4); EXPECT_EQ("foo", std::string(cord)); } -TEST(Cord, RemoveSuffixMakesZeroLengthNode) { +TEST_P(CordTest, RemoveSuffixMakesZeroLengthNode) { absl::Cord c; c.Append(absl::Cord(std::string(100, 'x'))); absl::Cord other_ref = c; // Prevent inplace appends + MaybeHarden(c); c.Append(absl::Cord(std::string(200, 'y'))); c.RemoveSuffix(200); EXPECT_EQ(std::string(100, 'x'), std::string(c)); @@ -672,24 +1196,27 @@ absl::Cord CordWithZedBlock(size_t size) { } // Establish that ZedBlock does what we think it does. -TEST(CordSpliceTest, ZedBlock) { +TEST_P(CordTest, CordSpliceTestZedBlock) { absl::Cord blob = CordWithZedBlock(10); + MaybeHarden(blob); EXPECT_EQ(10, blob.size()); std::string s; absl::CopyCordToString(blob, &s); EXPECT_EQ("zzzzzzzzzz", s); } -TEST(CordSpliceTest, ZedBlock0) { +TEST_P(CordTest, CordSpliceTestZedBlock0) { absl::Cord blob = CordWithZedBlock(0); + MaybeHarden(blob); EXPECT_EQ(0, blob.size()); std::string s; absl::CopyCordToString(blob, &s); EXPECT_EQ("", s); } -TEST(CordSpliceTest, ZedBlockSuffix1) { +TEST_P(CordTest, CordSpliceTestZedBlockSuffix1) { absl::Cord blob = CordWithZedBlock(10); + MaybeHarden(blob); EXPECT_EQ(10, blob.size()); absl::Cord suffix(blob); suffix.RemovePrefix(9); @@ -700,8 +1227,9 @@ TEST(CordSpliceTest, ZedBlockSuffix1) { } // Remove all of a prefix block -TEST(CordSpliceTest, ZedBlockSuffix0) { +TEST_P(CordTest, CordSpliceTestZedBlockSuffix0) { absl::Cord blob = CordWithZedBlock(10); + MaybeHarden(blob); EXPECT_EQ(10, blob.size()); absl::Cord suffix(blob); suffix.RemovePrefix(10); @@ -719,29 +1247,31 @@ absl::Cord BigCord(size_t len, char v) { // Splice block into cord. absl::Cord SpliceCord(const absl::Cord& blob, int64_t offset, const absl::Cord& block) { - ABSL_RAW_CHECK(offset >= 0, ""); - ABSL_RAW_CHECK(offset + block.size() <= blob.size(), ""); + CHECK_GE(offset, 0); + CHECK_LE(static_cast<size_t>(offset) + block.size(), blob.size()); absl::Cord result(blob); result.RemoveSuffix(blob.size() - offset); result.Append(block); absl::Cord suffix(blob); suffix.RemovePrefix(offset + block.size()); result.Append(suffix); - ABSL_RAW_CHECK(blob.size() == result.size(), ""); + CHECK_EQ(blob.size(), result.size()); return result; } // Taking an empty suffix of a block breaks appending. -TEST(CordSpliceTest, RemoveEntireBlock1) { +TEST_P(CordTest, CordSpliceTestRemoveEntireBlock1) { absl::Cord zero = CordWithZedBlock(10); + MaybeHarden(zero); absl::Cord suffix(zero); suffix.RemovePrefix(10); absl::Cord result; result.Append(suffix); } -TEST(CordSpliceTest, RemoveEntireBlock2) { +TEST_P(CordTest, CordSpliceTestRemoveEntireBlock2) { absl::Cord zero = CordWithZedBlock(10); + MaybeHarden(zero); absl::Cord prefix(zero); prefix.RemoveSuffix(10); absl::Cord suffix(zero); @@ -750,16 +1280,22 @@ TEST(CordSpliceTest, RemoveEntireBlock2) { result.Append(suffix); } -TEST(CordSpliceTest, RemoveEntireBlock3) { +TEST_P(CordTest, CordSpliceTestRemoveEntireBlock3) { absl::Cord blob = CordWithZedBlock(10); absl::Cord block = BigCord(10, 'b'); + MaybeHarden(blob); + MaybeHarden(block); blob = SpliceCord(blob, 0, block); } struct CordCompareTestCase { template <typename LHS, typename RHS> - CordCompareTestCase(const LHS& lhs, const RHS& rhs) - : lhs_cord(lhs), rhs_cord(rhs) {} + CordCompareTestCase(const LHS& lhs, const RHS& rhs, bool use_crc) + : lhs_cord(lhs), rhs_cord(rhs) { + if (use_crc) { + lhs_cord.SetExpectedChecksum(1); + } + } absl::Cord lhs_cord; absl::Cord rhs_cord; @@ -781,7 +1317,7 @@ void VerifyComparison(const CordCompareTestCase& test_case) { << "LHS=" << rhs_string << "; RHS=" << lhs_string; } -TEST(Cord, Compare) { +TEST_P(CordTest, Compare) { absl::Cord subcord("aaaaaBBBBBcccccDDDDD"); subcord = subcord.Subcord(3, 10); @@ -796,47 +1332,54 @@ TEST(Cord, Compare) { concat2.Append("cccccccccccDDDDDDDDDDDDDD"); concat2.Append("DD"); + const bool use_crc = UseCrc(); + std::vector<CordCompareTestCase> test_cases = {{ // Inline cords - {"abcdef", "abcdef"}, - {"abcdef", "abcdee"}, - {"abcdef", "abcdeg"}, - {"bbcdef", "abcdef"}, - {"bbcdef", "abcdeg"}, - {"abcdefa", "abcdef"}, - {"abcdef", "abcdefa"}, + {"abcdef", "abcdef", use_crc}, + {"abcdef", "abcdee", use_crc}, + {"abcdef", "abcdeg", use_crc}, + {"bbcdef", "abcdef", use_crc}, + {"bbcdef", "abcdeg", use_crc}, + {"abcdefa", "abcdef", use_crc}, + {"abcdef", "abcdefa", use_crc}, // Small flat cords - {"aaaaaBBBBBcccccDDDDD", "aaaaaBBBBBcccccDDDDD"}, - {"aaaaaBBBBBcccccDDDDD", "aaaaaBBBBBxccccDDDDD"}, - {"aaaaaBBBBBcxcccDDDDD", "aaaaaBBBBBcccccDDDDD"}, - {"aaaaaBBBBBxccccDDDDD", "aaaaaBBBBBcccccDDDDX"}, - {"aaaaaBBBBBcccccDDDDDa", "aaaaaBBBBBcccccDDDDD"}, - {"aaaaaBBBBBcccccDDDDD", "aaaaaBBBBBcccccDDDDDa"}, + {"aaaaaBBBBBcccccDDDDD", "aaaaaBBBBBcccccDDDDD", use_crc}, + {"aaaaaBBBBBcccccDDDDD", "aaaaaBBBBBxccccDDDDD", use_crc}, + {"aaaaaBBBBBcxcccDDDDD", "aaaaaBBBBBcccccDDDDD", use_crc}, + {"aaaaaBBBBBxccccDDDDD", "aaaaaBBBBBcccccDDDDX", use_crc}, + {"aaaaaBBBBBcccccDDDDDa", "aaaaaBBBBBcccccDDDDD", use_crc}, + {"aaaaaBBBBBcccccDDDDD", "aaaaaBBBBBcccccDDDDDa", use_crc}, // Subcords - {subcord, subcord}, - {subcord, "aaBBBBBccc"}, - {subcord, "aaBBBBBccd"}, - {subcord, "aaBBBBBccb"}, - {subcord, "aaBBBBBxcb"}, - {subcord, "aaBBBBBccca"}, - {subcord, "aaBBBBBcc"}, + {subcord, subcord, use_crc}, + {subcord, "aaBBBBBccc", use_crc}, + {subcord, "aaBBBBBccd", use_crc}, + {subcord, "aaBBBBBccb", use_crc}, + {subcord, "aaBBBBBxcb", use_crc}, + {subcord, "aaBBBBBccca", use_crc}, + {subcord, "aaBBBBBcc", use_crc}, // Concats - {concat, concat}, + {concat, concat, use_crc}, {concat, - "aaaaaaaaaaaaaaaaBBBBBBBBBBBBBBBBccccccccccccccccDDDDDDDDDDDDDDDD"}, + "aaaaaaaaaaaaaaaaBBBBBBBBBBBBBBBBccccccccccccccccDDDDDDDDDDDDDDDD", + use_crc}, {concat, - "aaaaaaaaaaaaaaaaBBBBBBBBBBBBBBBBcccccccccccccccxDDDDDDDDDDDDDDDD"}, + "aaaaaaaaaaaaaaaaBBBBBBBBBBBBBBBBcccccccccccccccxDDDDDDDDDDDDDDDD", + use_crc}, {concat, - "aaaaaaaaaaaaaaaaBBBBBBBBBBBBBBBBacccccccccccccccDDDDDDDDDDDDDDDD"}, + "aaaaaaaaaaaaaaaaBBBBBBBBBBBBBBBBacccccccccccccccDDDDDDDDDDDDDDDD", + use_crc}, {concat, - "aaaaaaaaaaaaaaaaBBBBBBBBBBBBBBBBccccccccccccccccDDDDDDDDDDDDDDD"}, + "aaaaaaaaaaaaaaaaBBBBBBBBBBBBBBBBccccccccccccccccDDDDDDDDDDDDDDD", + use_crc}, {concat, - "aaaaaaaaaaaaaaaaBBBBBBBBBBBBBBBBccccccccccccccccDDDDDDDDDDDDDDDDe"}, + "aaaaaaaaaaaaaaaaBBBBBBBBBBBBBBBBccccccccccccccccDDDDDDDDDDDDDDDDe", + use_crc}, - {concat, concat2}, + {concat, concat2, use_crc}, }}; for (const auto& tc : test_cases) { @@ -844,9 +1387,10 @@ TEST(Cord, Compare) { } } -TEST(Cord, CompareAfterAssign) { +TEST_P(CordTest, CompareAfterAssign) { absl::Cord a("aaaaaa1111111"); absl::Cord b("aaaaaa2222222"); + MaybeHarden(a); a = "cccccc"; b = "cccccc"; EXPECT_EQ(a, b); @@ -873,8 +1417,8 @@ static void TestCompare(const absl::Cord& c, const absl::Cord& d, EXPECT_EQ(expected, sign(c.Compare(d))) << c << ", " << d; } -TEST(Compare, ComparisonIsUnsigned) { - RandomEngine rng(testing::GTEST_FLAG(random_seed)); +TEST_P(CordTest, CompareComparisonIsUnsigned) { + RandomEngine rng(GTEST_FLAG_GET(random_seed)); std::uniform_int_distribution<uint32_t> uniform_uint8(0, 255); char x = static_cast<char>(uniform_uint8(rng)); TestCompare( @@ -882,9 +1426,9 @@ TEST(Compare, ComparisonIsUnsigned) { absl::Cord(std::string(GetUniformRandomUpTo(&rng, 100), x ^ 0x80)), &rng); } -TEST(Compare, RandomComparisons) { +TEST_P(CordTest, CompareRandomComparisons) { const int kIters = 5000; - RandomEngine rng(testing::GTEST_FLAG(random_seed)); + RandomEngine rng(GTEST_FLAG_GET(random_seed)); int n = GetUniformRandomUpTo(&rng, 5000); absl::Cord a[] = {MakeExternalCord(n), @@ -905,6 +1449,8 @@ TEST(Compare, RandomComparisons) { d.Append(a[GetUniformRandomUpTo(&rng, ABSL_ARRAYSIZE(a))]); } std::bernoulli_distribution coin_flip(0.5); + MaybeHarden(c); + MaybeHarden(d); TestCompare(coin_flip(rng) ? c : absl::Cord(std::string(c)), coin_flip(rng) ? d : absl::Cord(std::string(d)), &rng); } @@ -940,43 +1486,43 @@ void CompareOperators() { EXPECT_FALSE(b <= a); } -TEST(ComparisonOperators, Cord_Cord) { +TEST_P(CordTest, ComparisonOperators_Cord_Cord) { CompareOperators<absl::Cord, absl::Cord>(); } -TEST(ComparisonOperators, Cord_StringPiece) { +TEST_P(CordTest, ComparisonOperators_Cord_StringPiece) { CompareOperators<absl::Cord, absl::string_view>(); } -TEST(ComparisonOperators, StringPiece_Cord) { +TEST_P(CordTest, ComparisonOperators_StringPiece_Cord) { CompareOperators<absl::string_view, absl::Cord>(); } -TEST(ComparisonOperators, Cord_string) { +TEST_P(CordTest, ComparisonOperators_Cord_string) { CompareOperators<absl::Cord, std::string>(); } -TEST(ComparisonOperators, string_Cord) { +TEST_P(CordTest, ComparisonOperators_string_Cord) { CompareOperators<std::string, absl::Cord>(); } -TEST(ComparisonOperators, stdstring_Cord) { +TEST_P(CordTest, ComparisonOperators_stdstring_Cord) { CompareOperators<std::string, absl::Cord>(); } -TEST(ComparisonOperators, Cord_stdstring) { +TEST_P(CordTest, ComparisonOperators_Cord_stdstring) { CompareOperators<absl::Cord, std::string>(); } -TEST(ComparisonOperators, charstar_Cord) { +TEST_P(CordTest, ComparisonOperators_charstar_Cord) { CompareOperators<const char*, absl::Cord>(); } -TEST(ComparisonOperators, Cord_charstar) { +TEST_P(CordTest, ComparisonOperators_Cord_charstar) { CompareOperators<absl::Cord, const char*>(); } -TEST(ConstructFromExternal, ReleaserInvoked) { +TEST_P(CordTest, ConstructFromExternalReleaserInvoked) { // Empty external memory means the releaser should be called immediately. { bool invoked = false; @@ -1018,8 +1564,8 @@ TEST(ConstructFromExternal, ReleaserInvoked) { } } -TEST(ConstructFromExternal, CompareContents) { - RandomEngine rng(testing::GTEST_FLAG(random_seed)); +TEST_P(CordTest, ConstructFromExternalCompareContents) { + RandomEngine rng(GTEST_FLAG_GET(random_seed)); for (int length = 1; length <= 2048; length *= 2) { std::string data = RandomLowercaseString(&rng, length); @@ -1030,12 +1576,13 @@ TEST(ConstructFromExternal, CompareContents) { EXPECT_EQ(external->size(), sv.size()); delete external; }); + MaybeHarden(cord); EXPECT_EQ(data, cord); } } -TEST(ConstructFromExternal, LargeReleaser) { - RandomEngine rng(testing::GTEST_FLAG(random_seed)); +TEST_P(CordTest, ConstructFromExternalLargeReleaser) { + RandomEngine rng(GTEST_FLAG_GET(random_seed)); constexpr size_t kLength = 256; std::string data = RandomLowercaseString(&rng, kLength); std::array<char, kLength> data_array; @@ -1045,11 +1592,11 @@ TEST(ConstructFromExternal, LargeReleaser) { EXPECT_EQ(data, absl::string_view(data_array.data(), data_array.size())); invoked = true; }; - (void)absl::MakeCordFromExternal(data, releaser); + (void)MaybeHardened(absl::MakeCordFromExternal(data, releaser)); EXPECT_TRUE(invoked); } -TEST(ConstructFromExternal, FunctionPointerReleaser) { +TEST_P(CordTest, ConstructFromExternalFunctionPointerReleaser) { static absl::string_view data("hello world"); static bool invoked; auto* releaser = @@ -1058,15 +1605,15 @@ TEST(ConstructFromExternal, FunctionPointerReleaser) { invoked = true; }); invoked = false; - (void)absl::MakeCordFromExternal(data, releaser); + (void)MaybeHardened(absl::MakeCordFromExternal(data, releaser)); EXPECT_TRUE(invoked); invoked = false; - (void)absl::MakeCordFromExternal(data, *releaser); + (void)MaybeHardened(absl::MakeCordFromExternal(data, *releaser)); EXPECT_TRUE(invoked); } -TEST(ConstructFromExternal, MoveOnlyReleaser) { +TEST_P(CordTest, ConstructFromExternalMoveOnlyReleaser) { struct Releaser { explicit Releaser(bool* invoked) : invoked(invoked) {} Releaser(Releaser&& other) noexcept : invoked(other.invoked) {} @@ -1076,24 +1623,25 @@ TEST(ConstructFromExternal, MoveOnlyReleaser) { }; bool invoked = false; - (void)absl::MakeCordFromExternal("dummy", Releaser(&invoked)); + (void)MaybeHardened(absl::MakeCordFromExternal("dummy", Releaser(&invoked))); EXPECT_TRUE(invoked); } -TEST(ConstructFromExternal, NoArgLambda) { +TEST_P(CordTest, ConstructFromExternalNoArgLambda) { bool invoked = false; - (void)absl::MakeCordFromExternal("dummy", [&invoked]() { invoked = true; }); + (void)MaybeHardened( + absl::MakeCordFromExternal("dummy", [&invoked]() { invoked = true; })); EXPECT_TRUE(invoked); } -TEST(ConstructFromExternal, StringViewArgLambda) { +TEST_P(CordTest, ConstructFromExternalStringViewArgLambda) { bool invoked = false; - (void)absl::MakeCordFromExternal( - "dummy", [&invoked](absl::string_view) { invoked = true; }); + (void)MaybeHardened(absl::MakeCordFromExternal( + "dummy", [&invoked](absl::string_view) { invoked = true; })); EXPECT_TRUE(invoked); } -TEST(ConstructFromExternal, NonTrivialReleaserDestructor) { +TEST_P(CordTest, ConstructFromExternalNonTrivialReleaserDestructor) { struct Releaser { explicit Releaser(bool* destroyed) : destroyed(destroyed) {} ~Releaser() { *destroyed = true; } @@ -1104,57 +1652,94 @@ TEST(ConstructFromExternal, NonTrivialReleaserDestructor) { bool destroyed = false; Releaser releaser(&destroyed); - (void)absl::MakeCordFromExternal("dummy", releaser); + (void)MaybeHardened(absl::MakeCordFromExternal("dummy", releaser)); EXPECT_TRUE(destroyed); } -TEST(ConstructFromExternal, ReferenceQualifierOverloads) { - struct Releaser { - void operator()(absl::string_view) & { *lvalue_invoked = true; } - void operator()(absl::string_view) && { *rvalue_invoked = true; } +TEST_P(CordTest, ConstructFromExternalReferenceQualifierOverloads) { + enum InvokedAs { kMissing, kLValue, kRValue }; + enum CopiedAs { kNone, kMove, kCopy }; + struct Tracker { + CopiedAs copied_as = kNone; + InvokedAs invoked_as = kMissing; - bool* lvalue_invoked; - bool* rvalue_invoked; + void Record(InvokedAs rhs) { + ASSERT_EQ(invoked_as, kMissing); + invoked_as = rhs; + } + + void Record(CopiedAs rhs) { + if (copied_as == kNone || rhs == kCopy) copied_as = rhs; + } + } tracker; + + class Releaser { + public: + explicit Releaser(Tracker* tracker) : tr_(tracker) { *tracker = Tracker(); } + Releaser(Releaser&& rhs) : tr_(rhs.tr_) { tr_->Record(kMove); } + Releaser(const Releaser& rhs) : tr_(rhs.tr_) { tr_->Record(kCopy); } + + void operator()(absl::string_view) & { tr_->Record(kLValue); } + void operator()(absl::string_view) && { tr_->Record(kRValue); } + + private: + Tracker* tr_; }; - bool lvalue_invoked = false; - bool rvalue_invoked = false; - Releaser releaser = {&lvalue_invoked, &rvalue_invoked}; - (void)absl::MakeCordFromExternal("", releaser); - EXPECT_FALSE(lvalue_invoked); - EXPECT_TRUE(rvalue_invoked); - rvalue_invoked = false; + const Releaser releaser1(&tracker); + (void)MaybeHardened(absl::MakeCordFromExternal("", releaser1)); + EXPECT_EQ(tracker.copied_as, kCopy); + EXPECT_EQ(tracker.invoked_as, kRValue); + + const Releaser releaser2(&tracker); + (void)MaybeHardened(absl::MakeCordFromExternal("", releaser2)); + EXPECT_EQ(tracker.copied_as, kCopy); + EXPECT_EQ(tracker.invoked_as, kRValue); + + Releaser releaser3(&tracker); + (void)MaybeHardened(absl::MakeCordFromExternal("", std::move(releaser3))); + EXPECT_EQ(tracker.copied_as, kMove); + EXPECT_EQ(tracker.invoked_as, kRValue); - (void)absl::MakeCordFromExternal("dummy", releaser); - EXPECT_FALSE(lvalue_invoked); - EXPECT_TRUE(rvalue_invoked); - rvalue_invoked = false; + Releaser releaser4(&tracker); + (void)MaybeHardened(absl::MakeCordFromExternal("dummy", releaser4)); + EXPECT_EQ(tracker.copied_as, kCopy); + EXPECT_EQ(tracker.invoked_as, kRValue); - // NOLINTNEXTLINE: suppress clang-tidy std::move on trivially copyable type. - (void)absl::MakeCordFromExternal("dummy", std::move(releaser)); - EXPECT_FALSE(lvalue_invoked); - EXPECT_TRUE(rvalue_invoked); + const Releaser releaser5(&tracker); + (void)MaybeHardened(absl::MakeCordFromExternal("dummy", releaser5)); + EXPECT_EQ(tracker.copied_as, kCopy); + EXPECT_EQ(tracker.invoked_as, kRValue); + + Releaser releaser6(&tracker); + (void)MaybeHardened(absl::MakeCordFromExternal("foo", std::move(releaser6))); + EXPECT_EQ(tracker.copied_as, kMove); + EXPECT_EQ(tracker.invoked_as, kRValue); } -TEST(ExternalMemory, BasicUsage) { +TEST_P(CordTest, ExternalMemoryBasicUsage) { static const char* strings[] = {"", "hello", "there"}; for (const char* str : strings) { absl::Cord dst("(prefix)"); + MaybeHarden(dst); AddExternalMemory(str, &dst); + MaybeHarden(dst); dst.Append("(suffix)"); EXPECT_EQ((std::string("(prefix)") + str + std::string("(suffix)")), std::string(dst)); } } -TEST(ExternalMemory, RemovePrefixSuffix) { +TEST_P(CordTest, ExternalMemoryRemovePrefixSuffix) { // Exhaustively try all sub-strings. absl::Cord cord = MakeComposite(); std::string s = std::string(cord); for (int offset = 0; offset <= s.size(); offset++) { for (int length = 0; length <= s.size() - offset; length++) { absl::Cord result(cord); + MaybeHarden(result); result.RemovePrefix(offset); + MaybeHarden(result); result.RemoveSuffix(result.size() - length); EXPECT_EQ(s.substr(offset, length), std::string(result)) << offset << " " << length; @@ -1162,11 +1747,13 @@ TEST(ExternalMemory, RemovePrefixSuffix) { } } -TEST(ExternalMemory, Get) { +TEST_P(CordTest, ExternalMemoryGet) { absl::Cord cord("hello"); AddExternalMemory(" world!", &cord); + MaybeHarden(cord); AddExternalMemory(" how are ", &cord); cord.Append(" you?"); + MaybeHarden(cord); std::string s = std::string(cord); for (int i = 0; i < s.size(); i++) { EXPECT_EQ(s[i], cord[i]); @@ -1174,58 +1761,157 @@ TEST(ExternalMemory, Get) { } // CordMemoryUsage tests verify the correctness of the EstimatedMemoryUsage() -// These tests take into account that the reported memory usage is approximate -// and non-deterministic. For all tests, We verify that the reported memory -// usage is larger than `size()`, and less than `size() * 1.5` as a cord should -// never reserve more 'extra' capacity than half of its size as it grows. -// Additionally we have some whiteboxed expectations based on our knowledge of -// the layout and size of empty and inlined cords, and flat nodes. +// We use whiteboxed expectations based on our knowledge of the layout and size +// of empty and inlined cords, and flat nodes. + +constexpr auto kFairShare = absl::CordMemoryAccounting::kFairShare; +constexpr auto kTotalMorePrecise = + absl::CordMemoryAccounting::kTotalMorePrecise; -TEST(CordMemoryUsage, Empty) { - EXPECT_EQ(sizeof(absl::Cord), absl::Cord().EstimatedMemoryUsage()); +// Creates a cord of `n` `c` values, making sure no string stealing occurs. +absl::Cord MakeCord(size_t n, char c) { + const std::string s(n, c); + return absl::Cord(s); } -TEST(CordMemoryUsage, Embedded) { - absl::Cord a("hello"); - EXPECT_EQ(a.EstimatedMemoryUsage(), sizeof(absl::Cord)); +TEST(CordTest, CordMemoryUsageEmpty) { + absl::Cord cord; + EXPECT_EQ(sizeof(absl::Cord), cord.EstimatedMemoryUsage()); + EXPECT_EQ(sizeof(absl::Cord), cord.EstimatedMemoryUsage(kFairShare)); + EXPECT_EQ(sizeof(absl::Cord), cord.EstimatedMemoryUsage(kTotalMorePrecise)); } -TEST(CordMemoryUsage, EmbeddedAppend) { - absl::Cord a("a"); - absl::Cord b("bcd"); - EXPECT_EQ(b.EstimatedMemoryUsage(), sizeof(absl::Cord)); - a.Append(b); +TEST(CordTest, CordMemoryUsageInlined) { + absl::Cord a("hello"); EXPECT_EQ(a.EstimatedMemoryUsage(), sizeof(absl::Cord)); + EXPECT_EQ(a.EstimatedMemoryUsage(kFairShare), sizeof(absl::Cord)); + EXPECT_EQ(a.EstimatedMemoryUsage(kTotalMorePrecise), sizeof(absl::Cord)); } -TEST(CordMemoryUsage, ExternalMemory) { - static const int kLength = 1000; +TEST(CordTest, CordMemoryUsageExternalMemory) { absl::Cord cord; - AddExternalMemory(std::string(kLength, 'x'), &cord); - EXPECT_GT(cord.EstimatedMemoryUsage(), kLength); - EXPECT_LE(cord.EstimatedMemoryUsage(), kLength * 1.5); -} + AddExternalMemory(std::string(1000, 'x'), &cord); + const size_t expected = + sizeof(absl::Cord) + 1000 + sizeof(CordRepExternal) + sizeof(intptr_t); + EXPECT_EQ(cord.EstimatedMemoryUsage(), expected); + EXPECT_EQ(cord.EstimatedMemoryUsage(kFairShare), expected); + EXPECT_EQ(cord.EstimatedMemoryUsage(kTotalMorePrecise), expected); +} + +TEST(CordTest, CordMemoryUsageFlat) { + absl::Cord cord = MakeCord(1000, 'a'); + const size_t flat_size = + absl::CordTestPeer::Tree(cord)->flat()->AllocatedSize(); + EXPECT_EQ(cord.EstimatedMemoryUsage(), sizeof(absl::Cord) + flat_size); + EXPECT_EQ(cord.EstimatedMemoryUsage(kFairShare), + sizeof(absl::Cord) + flat_size); + EXPECT_EQ(cord.EstimatedMemoryUsage(kTotalMorePrecise), + sizeof(absl::Cord) + flat_size); +} + +TEST(CordTest, CordMemoryUsageSubStringSharedFlat) { + absl::Cord flat = MakeCord(2000, 'a'); + const size_t flat_size = + absl::CordTestPeer::Tree(flat)->flat()->AllocatedSize(); + absl::Cord cord = flat.Subcord(500, 1000); + EXPECT_EQ(cord.EstimatedMemoryUsage(), + sizeof(absl::Cord) + sizeof(CordRepSubstring) + flat_size); + EXPECT_EQ(cord.EstimatedMemoryUsage(kTotalMorePrecise), + sizeof(absl::Cord) + sizeof(CordRepSubstring) + flat_size); + EXPECT_EQ(cord.EstimatedMemoryUsage(kFairShare), + sizeof(absl::Cord) + sizeof(CordRepSubstring) + flat_size / 2); +} + +TEST(CordTest, CordMemoryUsageFlatShared) { + absl::Cord shared = MakeCord(1000, 'a'); + absl::Cord cord(shared); + const size_t flat_size = + absl::CordTestPeer::Tree(cord)->flat()->AllocatedSize(); + EXPECT_EQ(cord.EstimatedMemoryUsage(), sizeof(absl::Cord) + flat_size); + EXPECT_EQ(cord.EstimatedMemoryUsage(kTotalMorePrecise), + sizeof(absl::Cord) + flat_size); + EXPECT_EQ(cord.EstimatedMemoryUsage(kFairShare), + sizeof(absl::Cord) + flat_size / 2); +} + +TEST(CordTest, CordMemoryUsageFlatHardenedAndShared) { + absl::Cord shared = MakeCord(1000, 'a'); + absl::Cord cord(shared); + const size_t flat_size = + absl::CordTestPeer::Tree(cord)->flat()->AllocatedSize(); + cord.SetExpectedChecksum(1); + EXPECT_EQ(cord.EstimatedMemoryUsage(), + sizeof(absl::Cord) + sizeof(CordRepCrc) + flat_size); + EXPECT_EQ(cord.EstimatedMemoryUsage(kFairShare), + sizeof(absl::Cord) + sizeof(CordRepCrc) + flat_size / 2); + + absl::Cord cord2(cord); + EXPECT_EQ(cord2.EstimatedMemoryUsage(), + sizeof(absl::Cord) + sizeof(CordRepCrc) + flat_size); + EXPECT_EQ(cord2.EstimatedMemoryUsage(kTotalMorePrecise), + sizeof(absl::Cord) + sizeof(CordRepCrc) + flat_size); + EXPECT_EQ(cord2.EstimatedMemoryUsage(kFairShare), + sizeof(absl::Cord) + (sizeof(CordRepCrc) + flat_size / 2) / 2); +} + +TEST(CordTest, CordMemoryUsageBTree) { + absl::Cord cord1; + size_t flats1_size = 0; + absl::Cord flats1[4] = {MakeCord(1000, 'a'), MakeCord(1100, 'a'), + MakeCord(1200, 'a'), MakeCord(1300, 'a')}; + for (absl::Cord flat : flats1) { + flats1_size += absl::CordTestPeer::Tree(flat)->flat()->AllocatedSize(); + cord1.Append(std::move(flat)); + } -TEST(CordMemoryUsage, Flat) { - static const int kLength = 125; - absl::Cord a(std::string(kLength, 'a')); - EXPECT_GT(a.EstimatedMemoryUsage(), kLength); - EXPECT_LE(a.EstimatedMemoryUsage(), kLength * 1.5); -} + // Make sure the created cord is a BTREE tree. Under some builds such as + // windows DLL, we may have ODR like effects on the flag, meaning the DLL + // code will run with the picked up default. + if (!absl::CordTestPeer::Tree(cord1)->IsBtree()) { + LOG(WARNING) << "Cord library code not respecting btree flag"; + return; + } -TEST(CordMemoryUsage, AppendFlat) { - using absl::strings_internal::CordTestAccess; - absl::Cord a(std::string(CordTestAccess::MaxFlatLength(), 'a')); - size_t length = a.EstimatedMemoryUsage(); - a.Append(std::string(CordTestAccess::MaxFlatLength(), 'b')); - size_t delta = a.EstimatedMemoryUsage() - length; - EXPECT_GT(delta, CordTestAccess::MaxFlatLength()); - EXPECT_LE(delta, CordTestAccess::MaxFlatLength() * 1.5); + size_t rep1_size = sizeof(CordRepBtree) + flats1_size; + size_t rep1_shared_size = sizeof(CordRepBtree) + flats1_size / 2; + + EXPECT_EQ(cord1.EstimatedMemoryUsage(), sizeof(absl::Cord) + rep1_size); + EXPECT_EQ(cord1.EstimatedMemoryUsage(kTotalMorePrecise), + sizeof(absl::Cord) + rep1_size); + EXPECT_EQ(cord1.EstimatedMemoryUsage(kFairShare), + sizeof(absl::Cord) + rep1_shared_size); + + absl::Cord cord2; + size_t flats2_size = 0; + absl::Cord flats2[4] = {MakeCord(600, 'a'), MakeCord(700, 'a'), + MakeCord(800, 'a'), MakeCord(900, 'a')}; + for (absl::Cord& flat : flats2) { + flats2_size += absl::CordTestPeer::Tree(flat)->flat()->AllocatedSize(); + cord2.Append(std::move(flat)); + } + size_t rep2_size = sizeof(CordRepBtree) + flats2_size; + + EXPECT_EQ(cord2.EstimatedMemoryUsage(), sizeof(absl::Cord) + rep2_size); + EXPECT_EQ(cord2.EstimatedMemoryUsage(kTotalMorePrecise), + sizeof(absl::Cord) + rep2_size); + EXPECT_EQ(cord2.EstimatedMemoryUsage(kFairShare), + sizeof(absl::Cord) + rep2_size); + + absl::Cord cord(cord1); + cord.Append(std::move(cord2)); + + EXPECT_EQ(cord.EstimatedMemoryUsage(), + sizeof(absl::Cord) + sizeof(CordRepBtree) + rep1_size + rep2_size); + EXPECT_EQ(cord.EstimatedMemoryUsage(kTotalMorePrecise), + sizeof(absl::Cord) + sizeof(CordRepBtree) + rep1_size + rep2_size); + EXPECT_EQ(cord.EstimatedMemoryUsage(kFairShare), + sizeof(absl::Cord) + sizeof(CordRepBtree) + rep1_shared_size / 2 + + rep2_size); } // Regtest for a change that had to be rolled back because it expanded out // of the InlineRep too soon, which was observable through MemoryUsage(). -TEST(CordMemoryUsage, InlineRep) { +TEST_P(CordTest, CordMemoryUsageInlineRep) { constexpr size_t kMaxInline = 15; // Cord::InlineRep::N const std::string small_string(kMaxInline, 'x'); absl::Cord c1(small_string); @@ -1236,17 +1922,79 @@ TEST(CordMemoryUsage, InlineRep) { EXPECT_EQ(c1.EstimatedMemoryUsage(), c2.EstimatedMemoryUsage()); } +TEST_P(CordTest, CordMemoryUsageTotalMorePreciseMode) { + constexpr size_t kChunkSize = 2000; + std::string tmp_str(kChunkSize, 'x'); + const absl::Cord flat(std::move(tmp_str)); + + // Construct `fragmented` with two references into the same + // underlying buffer shared with `flat`: + absl::Cord fragmented(flat); + fragmented.Append(flat); + + // Memory usage of `flat`, minus the top-level Cord object: + const size_t flat_internal_usage = + flat.EstimatedMemoryUsage() - sizeof(absl::Cord); + + // `fragmented` holds a Cord and a CordRepBtree. That tree points to two + // copies of flat's internals, which we expect to dedup: + EXPECT_EQ(fragmented.EstimatedMemoryUsage(kTotalMorePrecise), + sizeof(absl::Cord) + + sizeof(CordRepBtree) + + flat_internal_usage); + + // This is a case where kTotal produces an overestimate: + EXPECT_EQ(fragmented.EstimatedMemoryUsage(), + sizeof(absl::Cord) + + sizeof(CordRepBtree) + + 2 * flat_internal_usage); +} + +TEST_P(CordTest, CordMemoryUsageTotalMorePreciseModeWithSubstring) { + constexpr size_t kChunkSize = 2000; + std::string tmp_str(kChunkSize, 'x'); + const absl::Cord flat(std::move(tmp_str)); + + // Construct `fragmented` with two references into the same + // underlying buffer shared with `flat`. + // + // This time, each reference is through a Subcord(): + absl::Cord fragmented; + fragmented.Append(flat.Subcord(1, kChunkSize - 2)); + fragmented.Append(flat.Subcord(1, kChunkSize - 2)); + + // Memory usage of `flat`, minus the top-level Cord object: + const size_t flat_internal_usage = + flat.EstimatedMemoryUsage() - sizeof(absl::Cord); + + // `fragmented` holds a Cord and a CordRepBtree. That tree points to two + // CordRepSubstrings, each pointing at flat's internals. + EXPECT_EQ(fragmented.EstimatedMemoryUsage(kTotalMorePrecise), + sizeof(absl::Cord) + + sizeof(CordRepBtree) + + 2 * sizeof(CordRepSubstring) + + flat_internal_usage); + + // This is a case where kTotal produces an overestimate: + EXPECT_EQ(fragmented.EstimatedMemoryUsage(), + sizeof(absl::Cord) + + sizeof(CordRepBtree) + + 2 * sizeof(CordRepSubstring) + + 2 * flat_internal_usage); +} } // namespace // Regtest for 7510292 (fix a bug introduced by 7465150) -TEST(Cord, Concat_Append) { +TEST_P(CordTest, Concat_Append) { // Create a rep of type CONCAT absl::Cord s1("foobarbarbarbarbar"); + MaybeHarden(s1); s1.Append("abcdefgabcdefgabcdefgabcdefgabcdefgabcdefgabcdefg"); size_t size = s1.size(); // Create a copy of s1 and append to it. absl::Cord s2 = s1; + MaybeHarden(s2); s2.Append("x"); // 7465150 modifies s1 when it shouldn't. @@ -1254,10 +2002,96 @@ TEST(Cord, Concat_Append) { EXPECT_EQ(s2.size(), size + 1); } -TEST(MakeFragmentedCord, MakeFragmentedCordFromInitializerList) { +TEST_P(CordTest, DiabolicalGrowth) { + // This test exercises a diabolical Append(<one char>) on a cord, making the + // cord shared before each Append call resulting in a terribly fragmented + // resulting cord. + // TODO(b/183983616): Apply some minimum compaction when copying a shared + // source cord into a mutable copy for updates in CordRepRing. + RandomEngine rng(GTEST_FLAG_GET(random_seed)); + const std::string expected = RandomLowercaseString(&rng, 5000); + absl::Cord cord; + for (char c : expected) { + absl::Cord shared(cord); + cord.Append(absl::string_view(&c, 1)); + MaybeHarden(cord); + } + std::string value; + absl::CopyCordToString(cord, &value); + EXPECT_EQ(value, expected); + LOG(INFO) << "Diabolical size allocated = " << cord.EstimatedMemoryUsage(); +} + +// The following tests check support for >4GB cords in 64-bit binaries, and +// 2GB-4GB cords in 32-bit binaries. This function returns the large cord size +// that's appropriate for the binary. + +// Construct a huge cord with the specified valid prefix. +static absl::Cord MakeHuge(absl::string_view prefix) { + absl::Cord cord; + if (sizeof(size_t) > 4) { + // In 64-bit binaries, test 64-bit Cord support. + const size_t size = + static_cast<size_t>(std::numeric_limits<uint32_t>::max()) + 314; + cord.Append(absl::MakeCordFromExternal( + absl::string_view(prefix.data(), size), + [](absl::string_view s) { DoNothing(s, nullptr); })); + } else { + // Cords are limited to 32-bit lengths in 32-bit binaries. The following + // tests check for use of "signed int" to represent Cord length/offset. + // However absl::string_view does not allow lengths >= (1u<<31), so we need + // to append in two parts; + const size_t s1 = (1u << 31) - 1; + // For shorter cord, `Append` copies the data rather than allocating a new + // node. The threshold is currently set to 511, so `s2` needs to be bigger + // to not trigger the copy. + const size_t s2 = 600; + cord.Append(absl::MakeCordFromExternal( + absl::string_view(prefix.data(), s1), + [](absl::string_view s) { DoNothing(s, nullptr); })); + cord.Append(absl::MakeCordFromExternal( + absl::string_view("", s2), + [](absl::string_view s) { DoNothing(s, nullptr); })); + } + return cord; +} + +TEST_P(CordTest, HugeCord) { + absl::Cord cord = MakeHuge("huge cord"); + MaybeHarden(cord); + + const size_t acceptable_delta = + 100 + (UseCrc() ? sizeof(absl::cord_internal::CordRepCrc) : 0); + EXPECT_LE(cord.size(), cord.EstimatedMemoryUsage()); + EXPECT_GE(cord.size() + acceptable_delta, cord.EstimatedMemoryUsage()); +} + +// Tests that Append() works ok when handed a self reference +TEST_P(CordTest, AppendSelf) { + // Test the empty case. + absl::Cord empty; + MaybeHarden(empty); + empty.Append(empty); + ASSERT_EQ(empty, ""); + + // We run the test until data is ~16K + // This guarantees it covers small, medium and large data. + std::string control_data = "Abc"; + absl::Cord data(control_data); + while (control_data.length() < 0x4000) { + MaybeHarden(data); + data.Append(data); + control_data.append(control_data); + ASSERT_EQ(control_data, data); + } +} + +TEST_P(CordTest, MakeFragmentedCordFromInitializerList) { absl::Cord fragmented = absl::MakeFragmentedCord({"A ", "fragmented ", "Cord"}); + MaybeHarden(fragmented); + EXPECT_EQ("A fragmented Cord", fragmented); auto chunk_it = fragmented.chunk_begin(); @@ -1274,10 +2108,12 @@ TEST(MakeFragmentedCord, MakeFragmentedCordFromInitializerList) { ASSERT_TRUE(++chunk_it == fragmented.chunk_end()); } -TEST(MakeFragmentedCord, MakeFragmentedCordFromVector) { +TEST_P(CordTest, MakeFragmentedCordFromVector) { std::vector<absl::string_view> chunks = {"A ", "fragmented ", "Cord"}; absl::Cord fragmented = absl::MakeFragmentedCord(chunks); + MaybeHarden(fragmented); + EXPECT_EQ("A fragmented Cord", fragmented); auto chunk_it = fragmented.chunk_begin(); @@ -1294,7 +2130,7 @@ TEST(MakeFragmentedCord, MakeFragmentedCordFromVector) { ASSERT_TRUE(++chunk_it == fragmented.chunk_end()); } -TEST(CordChunkIterator, Traits) { +TEST_P(CordTest, CordChunkIteratorTraits) { static_assert(std::is_copy_constructible<absl::Cord::ChunkIterator>::value, ""); static_assert(std::is_copy_assignable<absl::Cord::ChunkIterator>::value, ""); @@ -1375,39 +2211,115 @@ static void VerifyChunkIterator(const absl::Cord& cord, EXPECT_TRUE(post_iter == cord.chunk_end()); // NOLINT } -TEST(CordChunkIterator, Operations) { +TEST_P(CordTest, CordChunkIteratorOperations) { absl::Cord empty_cord; VerifyChunkIterator(empty_cord, 0); absl::Cord small_buffer_cord("small cord"); + MaybeHarden(small_buffer_cord); VerifyChunkIterator(small_buffer_cord, 1); absl::Cord flat_node_cord("larger than small buffer optimization"); + MaybeHarden(flat_node_cord); VerifyChunkIterator(flat_node_cord, 1); - VerifyChunkIterator( - absl::MakeFragmentedCord({"a ", "small ", "fragmented ", "cord ", "for ", - "testing ", "chunk ", "iterations."}), - 8); + VerifyChunkIterator(MaybeHardened(absl::MakeFragmentedCord( + {"a ", "small ", "fragmented ", "cord ", "for ", + "testing ", "chunk ", "iterations."})), + 8); absl::Cord reused_nodes_cord(std::string(40, 'c')); reused_nodes_cord.Prepend(absl::Cord(std::string(40, 'b'))); + MaybeHarden(reused_nodes_cord); reused_nodes_cord.Prepend(absl::Cord(std::string(40, 'a'))); size_t expected_chunks = 3; for (int i = 0; i < 8; ++i) { reused_nodes_cord.Prepend(reused_nodes_cord); + MaybeHarden(reused_nodes_cord); expected_chunks *= 2; VerifyChunkIterator(reused_nodes_cord, expected_chunks); } - RandomEngine rng(testing::GTEST_FLAG(random_seed)); + RandomEngine rng(GTEST_FLAG_GET(random_seed)); absl::Cord flat_cord(RandomLowercaseString(&rng, 256)); absl::Cord subcords; for (int i = 0; i < 128; ++i) subcords.Prepend(flat_cord.Subcord(i, 128)); VerifyChunkIterator(subcords, 128); } -TEST(CordCharIterator, Traits) { + +TEST_P(CordTest, AdvanceAndReadOnDataEdge) { + RandomEngine rng(GTEST_FLAG_GET(random_seed)); + const std::string data = RandomLowercaseString(&rng, 2000); + for (bool as_flat : {true, false}) { + SCOPED_TRACE(as_flat ? "Flat" : "External"); + + absl::Cord cord = + as_flat ? absl::Cord(data) + : absl::MakeCordFromExternal(data, [](absl::string_view) {}); + auto it = cord.Chars().begin(); +#if !defined(NDEBUG) || ABSL_OPTION_HARDENED + EXPECT_DEATH_IF_SUPPORTED(cord.AdvanceAndRead(&it, 2001), ".*"); +#endif + + it = cord.Chars().begin(); + absl::Cord frag = cord.AdvanceAndRead(&it, 2000); + EXPECT_EQ(frag, data); + EXPECT_TRUE(it == cord.Chars().end()); + + it = cord.Chars().begin(); + frag = cord.AdvanceAndRead(&it, 200); + EXPECT_EQ(frag, data.substr(0, 200)); + EXPECT_FALSE(it == cord.Chars().end()); + + frag = cord.AdvanceAndRead(&it, 1500); + EXPECT_EQ(frag, data.substr(200, 1500)); + EXPECT_FALSE(it == cord.Chars().end()); + + frag = cord.AdvanceAndRead(&it, 300); + EXPECT_EQ(frag, data.substr(1700, 300)); + EXPECT_TRUE(it == cord.Chars().end()); + } +} + +TEST_P(CordTest, AdvanceAndReadOnSubstringDataEdge) { + RandomEngine rng(GTEST_FLAG_GET(random_seed)); + const std::string data = RandomLowercaseString(&rng, 2500); + for (bool as_flat : {true, false}) { + SCOPED_TRACE(as_flat ? "Flat" : "External"); + + absl::Cord cord = + as_flat ? absl::Cord(data) + : absl::MakeCordFromExternal(data, [](absl::string_view) {}); + cord = cord.Subcord(200, 2000); + const std::string substr = data.substr(200, 2000); + + auto it = cord.Chars().begin(); +#if !defined(NDEBUG) || ABSL_OPTION_HARDENED + EXPECT_DEATH_IF_SUPPORTED(cord.AdvanceAndRead(&it, 2001), ".*"); +#endif + + it = cord.Chars().begin(); + absl::Cord frag = cord.AdvanceAndRead(&it, 2000); + EXPECT_EQ(frag, substr); + EXPECT_TRUE(it == cord.Chars().end()); + + it = cord.Chars().begin(); + frag = cord.AdvanceAndRead(&it, 200); + EXPECT_EQ(frag, substr.substr(0, 200)); + EXPECT_FALSE(it == cord.Chars().end()); + + frag = cord.AdvanceAndRead(&it, 1500); + EXPECT_EQ(frag, substr.substr(200, 1500)); + EXPECT_FALSE(it == cord.Chars().end()); + + frag = cord.AdvanceAndRead(&it, 300); + EXPECT_EQ(frag, substr.substr(1700, 300)); + EXPECT_TRUE(it == cord.Chars().end()); + } +} + +TEST_P(CordTest, CharIteratorTraits) { static_assert(std::is_copy_constructible<absl::Cord::CharIterator>::value, ""); static_assert(std::is_copy_assignable<absl::Cord::CharIterator>::value, ""); @@ -1516,44 +2428,88 @@ static void VerifyCharIterator(const absl::Cord& cord) { } } -TEST(CordCharIterator, Operations) { +TEST_P(CordTest, CharIteratorOperations) { absl::Cord empty_cord; VerifyCharIterator(empty_cord); absl::Cord small_buffer_cord("small cord"); + MaybeHarden(small_buffer_cord); VerifyCharIterator(small_buffer_cord); absl::Cord flat_node_cord("larger than small buffer optimization"); + MaybeHarden(flat_node_cord); VerifyCharIterator(flat_node_cord); - VerifyCharIterator( + VerifyCharIterator(MaybeHardened( absl::MakeFragmentedCord({"a ", "small ", "fragmented ", "cord ", "for ", - "testing ", "character ", "iteration."})); + "testing ", "character ", "iteration."}))); absl::Cord reused_nodes_cord("ghi"); reused_nodes_cord.Prepend(absl::Cord("def")); reused_nodes_cord.Prepend(absl::Cord("abc")); for (int i = 0; i < 4; ++i) { reused_nodes_cord.Prepend(reused_nodes_cord); + MaybeHarden(reused_nodes_cord); VerifyCharIterator(reused_nodes_cord); } - RandomEngine rng(testing::GTEST_FLAG(random_seed)); + RandomEngine rng(GTEST_FLAG_GET(random_seed)); absl::Cord flat_cord(RandomLowercaseString(&rng, 256)); absl::Cord subcords; - for (int i = 0; i < 4; ++i) subcords.Prepend(flat_cord.Subcord(16 * i, 128)); + for (int i = 0; i < 4; ++i) { + subcords.Prepend(flat_cord.Subcord(16 * i, 128)); + MaybeHarden(subcords); + } VerifyCharIterator(subcords); } -TEST(Cord, StreamingOutput) { +TEST_P(CordTest, CharIteratorAdvanceAndRead) { + // Create a Cord holding 6 flats of 2500 bytes each, and then iterate over it + // reading 150, 1500, 2500 and 3000 bytes. This will result in all possible + // partial, full and straddled read combinations including reads below + // kMaxBytesToCopy. b/197776822 surfaced a bug for a specific partial, small + // read 'at end' on Cord which caused a failure on attempting to read past the + // end in CordRepBtreeReader which was not covered by any existing test. + constexpr int kBlocks = 6; + constexpr size_t kBlockSize = 2500; + constexpr size_t kChunkSize1 = 1500; + constexpr size_t kChunkSize2 = 2500; + constexpr size_t kChunkSize3 = 3000; + constexpr size_t kChunkSize4 = 150; + RandomEngine rng; + std::string data = RandomLowercaseString(&rng, kBlocks * kBlockSize); + absl::Cord cord; + for (int i = 0; i < kBlocks; ++i) { + const std::string block = data.substr(i * kBlockSize, kBlockSize); + cord.Append(absl::Cord(block)); + } + + MaybeHarden(cord); + + for (size_t chunk_size : + {kChunkSize1, kChunkSize2, kChunkSize3, kChunkSize4}) { + absl::Cord::CharIterator it = cord.char_begin(); + size_t offset = 0; + while (offset < data.length()) { + const size_t n = std::min<size_t>(data.length() - offset, chunk_size); + absl::Cord chunk = cord.AdvanceAndRead(&it, n); + ASSERT_EQ(chunk.size(), n); + ASSERT_EQ(chunk.Compare(data.substr(offset, n)), 0); + offset += n; + } + } +} + +TEST_P(CordTest, StreamingOutput) { absl::Cord c = absl::MakeFragmentedCord({"A ", "small ", "fragmented ", "Cord", "."}); + MaybeHarden(c); std::stringstream output; output << c; EXPECT_EQ("A small fragmented Cord.", output.str()); } -TEST(Cord, ForEachChunk) { +TEST_P(CordTest, ForEachChunk) { for (int num_elements : {1, 10, 200}) { SCOPED_TRACE(num_elements); std::vector<std::string> cord_chunks; @@ -1561,6 +2517,7 @@ TEST(Cord, ForEachChunk) { cord_chunks.push_back(absl::StrCat("[", i, "]")); } absl::Cord c = absl::MakeFragmentedCord(cord_chunks); + MaybeHarden(c); std::vector<std::string> iterated_chunks; absl::CordTestPeer::ForEachChunk(c, @@ -1571,13 +2528,14 @@ TEST(Cord, ForEachChunk) { } } -TEST(Cord, SmallBufferAssignFromOwnData) { +TEST_P(CordTest, SmallBufferAssignFromOwnData) { constexpr size_t kMaxInline = 15; std::string contents = "small buff cord"; EXPECT_EQ(contents.size(), kMaxInline); for (size_t pos = 0; pos < contents.size(); ++pos) { for (size_t count = contents.size() - pos; count > 0; --count) { absl::Cord c(contents); + MaybeHarden(c); absl::string_view flat = c.Flatten(); c = flat.substr(pos, count); EXPECT_EQ(c, contents.substr(pos, count)) @@ -1586,16 +2544,20 @@ TEST(Cord, SmallBufferAssignFromOwnData) { } } -TEST(Cord, Format) { +TEST_P(CordTest, Format) { absl::Cord c; absl::Format(&c, "There were %04d little %s.", 3, "pigs"); EXPECT_EQ(c, "There were 0003 little pigs."); + MaybeHarden(c); absl::Format(&c, "And %-3llx bad wolf!", 1); + MaybeHarden(c); EXPECT_EQ(c, "There were 0003 little pigs.And 1 bad wolf!"); } -TEST(CordDeathTest, Hardening) { +TEST_P(CordTest, Hardening) { absl::Cord cord("hello"); + MaybeHarden(cord); + // These statement should abort the program in all builds modes. EXPECT_DEATH_IF_SUPPORTED(cord.RemovePrefix(6), ""); EXPECT_DEATH_IF_SUPPORTED(cord.RemoveSuffix(6), ""); @@ -1613,3 +2575,631 @@ TEST(CordDeathTest, Hardening) { EXPECT_DEATH_IF_SUPPORTED(static_cast<void>(cord.chunk_end()->empty()), ""); EXPECT_DEATH_IF_SUPPORTED(++cord.chunk_end(), ""); } + +// This test mimics a specific (and rare) application repeatedly splitting a +// cord, inserting (overwriting) a string value, and composing a new cord from +// the three pieces. This is hostile towards a Btree implementation: A split of +// a node at any level is likely to have the right-most edge of the left split, +// and the left-most edge of the right split shared. For example, splitting a +// leaf node with 6 edges will result likely in a 1-6, 2-5, 3-4, etc. split, +// sharing the 'split node'. When recomposing such nodes, we 'injected' an edge +// in that node. As this happens with some probability on each level of the +// tree, this will quickly grow the tree until it reaches maximum height. +TEST_P(CordTest, BtreeHostileSplitInsertJoin) { + absl::BitGen bitgen; + + // Start with about 1GB of data + std::string data(1 << 10, 'x'); + absl::Cord buffer(data); + absl::Cord cord; + for (int i = 0; i < 1000000; ++i) { + cord.Append(buffer); + } + + for (int j = 0; j < 1000; ++j) { + MaybeHarden(cord); + size_t offset = absl::Uniform(bitgen, 0u, cord.size()); + size_t length = absl::Uniform(bitgen, 100u, data.size()); + if (cord.size() == offset) { + cord.Append(absl::string_view(data.data(), length)); + } else { + absl::Cord suffix; + if (offset + length < cord.size()) { + suffix = cord; + suffix.RemovePrefix(offset + length); + } + if (cord.size() > offset) { + cord.RemoveSuffix(cord.size() - offset); + } + cord.Append(absl::string_view(data.data(), length)); + if (!suffix.empty()) { + cord.Append(suffix); + } + } + } +} + +class AfterExitCordTester { + public: + bool Set(absl::Cord* cord, absl::string_view expected) { + cord_ = cord; + expected_ = expected; + return true; + } + + ~AfterExitCordTester() { + EXPECT_EQ(*cord_, expected_); + } + private: + absl::Cord* cord_; + absl::string_view expected_; +}; + +// Deliberately prevents the destructor for an absl::Cord from running. The cord +// is accessible via the cord member during the lifetime of the CordLeaker. +// After the CordLeaker is destroyed, pointers to the cord will remain valid +// until the CordLeaker's memory is deallocated. +struct CordLeaker { + union { + absl::Cord cord; + }; + + template <typename Str> + constexpr explicit CordLeaker(const Str& str) : cord(str) {} + + ~CordLeaker() { + // Don't do anything, including running cord's destructor. (cord's + // destructor won't run automatically because cord is hidden inside a + // union.) + } +}; + +template <typename Str> +void TestConstinitConstructor(Str) { + const auto expected = Str::value; + // Defined before `cord` to be destroyed after it. + static AfterExitCordTester exit_tester; // NOLINT + ABSL_CONST_INIT static CordLeaker cord_leaker(Str{}); // NOLINT + // cord_leaker is static, so this reference will remain valid through the end + // of program execution. + static absl::Cord& cord = cord_leaker.cord; + static bool init_exit_tester = exit_tester.Set(&cord, expected); + (void)init_exit_tester; + + EXPECT_EQ(cord, expected); + // Copy the object and test the copy, and the original. + { + absl::Cord copy = cord; + EXPECT_EQ(copy, expected); + } + // The original still works + EXPECT_EQ(cord, expected); + + // Try making adding more structure to the tree. + { + absl::Cord copy = cord; + std::string expected_copy(expected); + for (int i = 0; i < 10; ++i) { + copy.Append(cord); + absl::StrAppend(&expected_copy, expected); + EXPECT_EQ(copy, expected_copy); + } + } + + // Make sure we are using the right branch during constant evaluation. + EXPECT_EQ(absl::CordTestPeer::IsTree(cord), cord.size() >= 16); + + for (int i = 0; i < 10; ++i) { + // Make a few more Cords from the same global rep. + // This tests what happens when the refcount for it gets below 1. + EXPECT_EQ(expected, absl::Cord(Str{})); + } +} + +constexpr int SimpleStrlen(const char* p) { + return *p ? 1 + SimpleStrlen(p + 1) : 0; +} + +struct ShortView { + constexpr absl::string_view operator()() const { + return absl::string_view("SSO string", SimpleStrlen("SSO string")); + } +}; + +struct LongView { + constexpr absl::string_view operator()() const { + return absl::string_view("String that does not fit SSO.", + SimpleStrlen("String that does not fit SSO.")); + } +}; + + +TEST_P(CordTest, ConstinitConstructor) { + TestConstinitConstructor( + absl::strings_internal::MakeStringConstant(ShortView{})); + TestConstinitConstructor( + absl::strings_internal::MakeStringConstant(LongView{})); +} + +namespace { + +// Test helper that generates a populated cord for future manipulation. +// +// By test convention, all generated cords begin with the characters "abcde" at +// the start of the first chunk. +class PopulatedCordFactory { + public: + constexpr PopulatedCordFactory(absl::string_view name, + absl::Cord (*generator)()) + : name_(name), generator_(generator) {} + + absl::string_view Name() const { return name_; } + absl::Cord Generate() const { return generator_(); } + + private: + absl::string_view name_; + absl::Cord (*generator_)(); +}; + +// clang-format off +// This array is constant-initialized in conformant compilers. +PopulatedCordFactory cord_factories[] = { + {"sso", [] { return absl::Cord("abcde"); }}, + {"flat", [] { + // Too large to live in SSO space, but small enough to be a simple FLAT. + absl::Cord flat(absl::StrCat("abcde", std::string(1000, 'x'))); + flat.Flatten(); + return flat; + }}, + {"external", [] { + // A cheat: we are using a string literal as the external storage, so a + // no-op releaser is correct here. + return absl::MakeCordFromExternal("abcde External!", []{}); + }}, + {"external substring", [] { + // A cheat: we are using a string literal as the external storage, so a + // no-op releaser is correct here. + absl::Cord ext = absl::MakeCordFromExternal("-abcde External!", []{}); + return absl::CordTestPeer::MakeSubstring(ext, 1, ext.size() - 1); + }}, + {"substring", [] { + absl::Cord flat(absl::StrCat("-abcde", std::string(1000, 'x'))); + flat.Flatten(); + return flat.Subcord(1, 998); + }}, + {"fragmented", [] { + std::string fragment = absl::StrCat("abcde", std::string(195, 'x')); + std::vector<std::string> fragments(200, fragment); + absl::Cord cord = absl::MakeFragmentedCord(fragments); + assert(cord.size() == 40000); + return cord; + }}, +}; +// clang-format on + +// Test helper that can mutate a cord, and possibly undo the mutation, for +// testing. +class CordMutator { + public: + constexpr CordMutator(absl::string_view name, void (*mutate)(absl::Cord&), + void (*undo)(absl::Cord&) = nullptr) + : name_(name), mutate_(mutate), undo_(undo) {} + + absl::string_view Name() const { return name_; } + void Mutate(absl::Cord& cord) const { mutate_(cord); } + bool CanUndo() const { return undo_ != nullptr; } + void Undo(absl::Cord& cord) const { undo_(cord); } + + private: + absl::string_view name_; + void (*mutate_)(absl::Cord&); + void (*undo_)(absl::Cord&); +}; + +// clang-format off +// This array is constant-initialized in conformant compilers. +CordMutator cord_mutators[] = { + {"clear", [](absl::Cord& c) { c.Clear(); }}, + {"overwrite", [](absl::Cord& c) { c = "overwritten"; }}, + { + "append string", + [](absl::Cord& c) { c.Append("0123456789"); }, + [](absl::Cord& c) { c.RemoveSuffix(10); } + }, + { + "append cord", + [](absl::Cord& c) { + c.Append(absl::MakeFragmentedCord({"12345", "67890"})); + }, + [](absl::Cord& c) { c.RemoveSuffix(10); } + }, + { + "append checksummed cord", + [](absl::Cord& c) { + absl::Cord to_append = absl::MakeFragmentedCord({"12345", "67890"}); + to_append.SetExpectedChecksum(999); + c.Append(to_append); + }, + [](absl::Cord& c) { c.RemoveSuffix(10); } + }, + { + "append self", + [](absl::Cord& c) { c.Append(c); }, + [](absl::Cord& c) { c.RemoveSuffix(c.size() / 2); } + }, + { + "append empty string", + [](absl::Cord& c) { c.Append(""); }, + [](absl::Cord& c) { } + }, + { + "append empty cord", + [](absl::Cord& c) { c.Append(absl::Cord()); }, + [](absl::Cord& c) { } + }, + { + "append empty checksummed cord", + [](absl::Cord& c) { + absl::Cord to_append; + to_append.SetExpectedChecksum(999); + c.Append(to_append); + }, + [](absl::Cord& c) { } + }, + { + "prepend string", + [](absl::Cord& c) { c.Prepend("9876543210"); }, + [](absl::Cord& c) { c.RemovePrefix(10); } + }, + { + "prepend cord", + [](absl::Cord& c) { + c.Prepend(absl::MakeFragmentedCord({"98765", "43210"})); + }, + [](absl::Cord& c) { c.RemovePrefix(10); } + }, + { + "prepend checksummed cord", + [](absl::Cord& c) { + absl::Cord to_prepend = absl::MakeFragmentedCord({"98765", "43210"}); + to_prepend.SetExpectedChecksum(999); + c.Prepend(to_prepend); + }, + [](absl::Cord& c) { c.RemovePrefix(10); } + }, + { + "prepend empty string", + [](absl::Cord& c) { c.Prepend(""); }, + [](absl::Cord& c) { } + }, + { + "prepend empty cord", + [](absl::Cord& c) { c.Prepend(absl::Cord()); }, + [](absl::Cord& c) { } + }, + { + "prepend empty checksummed cord", + [](absl::Cord& c) { + absl::Cord to_prepend; + to_prepend.SetExpectedChecksum(999); + c.Prepend(to_prepend); + }, + [](absl::Cord& c) { } + }, + { + "prepend self", + [](absl::Cord& c) { c.Prepend(c); }, + [](absl::Cord& c) { c.RemovePrefix(c.size() / 2); } + }, + {"remove prefix", [](absl::Cord& c) { c.RemovePrefix(c.size() / 2); }}, + {"remove suffix", [](absl::Cord& c) { c.RemoveSuffix(c.size() / 2); }}, + {"remove 0-prefix", [](absl::Cord& c) { c.RemovePrefix(0); }}, + {"remove 0-suffix", [](absl::Cord& c) { c.RemoveSuffix(0); }}, + {"subcord", [](absl::Cord& c) { c = c.Subcord(1, c.size() - 2); }}, + { + "swap inline", + [](absl::Cord& c) { + absl::Cord other("swap"); + c.swap(other); + } + }, + { + "swap tree", + [](absl::Cord& c) { + absl::Cord other(std::string(10000, 'x')); + c.swap(other); + } + }, +}; +// clang-format on +} // namespace + +TEST_P(CordTest, ExpectedChecksum) { + for (const PopulatedCordFactory& factory : cord_factories) { + SCOPED_TRACE(factory.Name()); + for (bool shared : {false, true}) { + SCOPED_TRACE(shared); + + absl::Cord shared_cord_source = factory.Generate(); + auto make_instance = [=] { + return shared ? shared_cord_source : factory.Generate(); + }; + + const absl::Cord base_value = factory.Generate(); + const std::string base_value_as_string(factory.Generate().Flatten()); + + absl::Cord c1 = make_instance(); + EXPECT_FALSE(c1.ExpectedChecksum().has_value()); + + // Setting an expected checksum works, and retains the cord's bytes + c1.SetExpectedChecksum(12345); + EXPECT_EQ(c1.ExpectedChecksum().value_or(0), 12345); + EXPECT_EQ(c1, base_value); + + // Test that setting an expected checksum again doesn't crash or leak + // memory. + c1.SetExpectedChecksum(12345); + EXPECT_EQ(c1.ExpectedChecksum().value_or(0), 12345); + EXPECT_EQ(c1, base_value); + + // CRC persists through copies, assignments, and moves: + absl::Cord c1_copy_construct = c1; + EXPECT_EQ(c1_copy_construct.ExpectedChecksum().value_or(0), 12345); + + absl::Cord c1_copy_assign; + c1_copy_assign = c1; + EXPECT_EQ(c1_copy_assign.ExpectedChecksum().value_or(0), 12345); + + absl::Cord c1_move(std::move(c1_copy_assign)); + EXPECT_EQ(c1_move.ExpectedChecksum().value_or(0), 12345); + + EXPECT_EQ(c1.ExpectedChecksum().value_or(0), 12345); + + // A CRC Cord compares equal to its non-CRC value. + EXPECT_EQ(c1, make_instance()); + + for (const CordMutator& mutator : cord_mutators) { + SCOPED_TRACE(mutator.Name()); + + // Test that mutating a cord removes its stored checksum + absl::Cord c2 = make_instance(); + c2.SetExpectedChecksum(24680); + + mutator.Mutate(c2); + + if (c1 == c2) { + // Not a mutation (for example, appending the empty string). + // Whether the checksum is removed is not defined. + continue; + } + + EXPECT_EQ(c2.ExpectedChecksum(), absl::nullopt); + + if (mutator.CanUndo()) { + // Undoing an operation should not restore the checksum + mutator.Undo(c2); + EXPECT_EQ(c2, base_value); + EXPECT_EQ(c2.ExpectedChecksum(), absl::nullopt); + } + } + + absl::Cord c3 = make_instance(); + c3.SetExpectedChecksum(999); + const absl::Cord& cc3 = c3; + + // Test that all cord reading operations function in the face of an + // expected checksum. + + // Test data precondition + ASSERT_TRUE(cc3.StartsWith("abcde")); + + EXPECT_EQ(cc3.size(), base_value_as_string.size()); + EXPECT_FALSE(cc3.empty()); + EXPECT_EQ(cc3.Compare(base_value), 0); + EXPECT_EQ(cc3.Compare(base_value_as_string), 0); + EXPECT_EQ(cc3.Compare("wxyz"), -1); + EXPECT_EQ(cc3.Compare(absl::Cord("wxyz")), -1); + EXPECT_EQ(cc3.Compare("aaaa"), 1); + EXPECT_EQ(cc3.Compare(absl::Cord("aaaa")), 1); + EXPECT_EQ(absl::Cord("wxyz").Compare(cc3), 1); + EXPECT_EQ(absl::Cord("aaaa").Compare(cc3), -1); + EXPECT_TRUE(cc3.StartsWith("abcd")); + EXPECT_EQ(std::string(cc3), base_value_as_string); + + std::string dest; + absl::CopyCordToString(cc3, &dest); + EXPECT_EQ(dest, base_value_as_string); + + bool first_pass = true; + for (absl::string_view chunk : cc3.Chunks()) { + if (first_pass) { + EXPECT_TRUE(absl::StartsWith(chunk, "abcde")); + } + first_pass = false; + } + first_pass = true; + for (char ch : cc3.Chars()) { + if (first_pass) { + EXPECT_EQ(ch, 'a'); + } + first_pass = false; + } + EXPECT_TRUE(absl::StartsWith(*cc3.chunk_begin(), "abcde")); + EXPECT_EQ(*cc3.char_begin(), 'a'); + + auto char_it = cc3.char_begin(); + absl::Cord::Advance(&char_it, 2); + EXPECT_EQ(absl::Cord::AdvanceAndRead(&char_it, 2), "cd"); + EXPECT_EQ(*char_it, 'e'); + char_it = cc3.char_begin(); + absl::Cord::Advance(&char_it, 2); + EXPECT_TRUE(absl::StartsWith(absl::Cord::ChunkRemaining(char_it), "cde")); + + EXPECT_EQ(cc3[0], 'a'); + EXPECT_EQ(cc3[4], 'e'); + EXPECT_EQ(absl::HashOf(cc3), absl::HashOf(base_value)); + EXPECT_EQ(absl::HashOf(cc3), absl::HashOf(base_value_as_string)); + } + } +} + +// Test the special cases encountered with an empty checksummed cord. +TEST_P(CordTest, ChecksummedEmptyCord) { + absl::Cord c1; + EXPECT_FALSE(c1.ExpectedChecksum().has_value()); + + // Setting an expected checksum works. + c1.SetExpectedChecksum(12345); + EXPECT_EQ(c1.ExpectedChecksum().value_or(0), 12345); + EXPECT_EQ(c1, ""); + EXPECT_TRUE(c1.empty()); + + // Test that setting an expected checksum again doesn't crash or leak memory. + c1.SetExpectedChecksum(12345); + EXPECT_EQ(c1.ExpectedChecksum().value_or(0), 12345); + EXPECT_EQ(c1, ""); + EXPECT_TRUE(c1.empty()); + + // CRC persists through copies, assignments, and moves: + absl::Cord c1_copy_construct = c1; + EXPECT_EQ(c1_copy_construct.ExpectedChecksum().value_or(0), 12345); + + absl::Cord c1_copy_assign; + c1_copy_assign = c1; + EXPECT_EQ(c1_copy_assign.ExpectedChecksum().value_or(0), 12345); + + absl::Cord c1_move(std::move(c1_copy_assign)); + EXPECT_EQ(c1_move.ExpectedChecksum().value_or(0), 12345); + + EXPECT_EQ(c1.ExpectedChecksum().value_or(0), 12345); + + // A CRC Cord compares equal to its non-CRC value. + EXPECT_EQ(c1, absl::Cord()); + + for (const CordMutator& mutator : cord_mutators) { + SCOPED_TRACE(mutator.Name()); + + // Exercise mutating an empty checksummed cord to catch crashes and exercise + // memory sanitizers. + absl::Cord c2; + c2.SetExpectedChecksum(24680); + mutator.Mutate(c2); + + if (c2.empty()) { + // Not a mutation + continue; + } + EXPECT_EQ(c2.ExpectedChecksum(), absl::nullopt); + + if (mutator.CanUndo()) { + mutator.Undo(c2); + } + } + + absl::Cord c3; + c3.SetExpectedChecksum(999); + const absl::Cord& cc3 = c3; + + // Test that all cord reading operations function in the face of an + // expected checksum. + EXPECT_TRUE(cc3.StartsWith("")); + EXPECT_TRUE(cc3.EndsWith("")); + EXPECT_TRUE(cc3.empty()); + EXPECT_EQ(cc3, ""); + EXPECT_EQ(cc3, absl::Cord()); + EXPECT_EQ(cc3.size(), 0); + EXPECT_EQ(cc3.Compare(absl::Cord()), 0); + EXPECT_EQ(cc3.Compare(c1), 0); + EXPECT_EQ(cc3.Compare(cc3), 0); + EXPECT_EQ(cc3.Compare(""), 0); + EXPECT_EQ(cc3.Compare("wxyz"), -1); + EXPECT_EQ(cc3.Compare(absl::Cord("wxyz")), -1); + EXPECT_EQ(absl::Cord("wxyz").Compare(cc3), 1); + EXPECT_EQ(std::string(cc3), ""); + + std::string dest; + absl::CopyCordToString(cc3, &dest); + EXPECT_EQ(dest, ""); + + for (absl::string_view chunk : cc3.Chunks()) { // NOLINT(unreachable loop) + static_cast<void>(chunk); + GTEST_FAIL() << "no chunks expected"; + } + EXPECT_TRUE(cc3.chunk_begin() == cc3.chunk_end()); + + for (char ch : cc3.Chars()) { // NOLINT(unreachable loop) + static_cast<void>(ch); + GTEST_FAIL() << "no chars expected"; + } + EXPECT_TRUE(cc3.char_begin() == cc3.char_end()); + + EXPECT_EQ(cc3.TryFlat(), ""); + EXPECT_EQ(absl::HashOf(c3), absl::HashOf(absl::Cord())); + EXPECT_EQ(absl::HashOf(c3), absl::HashOf(absl::string_view())); +} + +#if defined(GTEST_HAS_DEATH_TEST) && defined(ABSL_INTERNAL_CORD_HAVE_SANITIZER) + +// Returns an expected poison / uninitialized death message expression. +const char* MASanDeathExpr() { + return "(use-after-poison|use-of-uninitialized-value)"; +} + +TEST(CordSanitizerTest, SanitizesEmptyCord) { + absl::Cord cord; + const char* data = cord.Flatten().data(); + EXPECT_DEATH(EXPECT_EQ(data[0], 0), MASanDeathExpr()); +} + +TEST(CordSanitizerTest, SanitizesSmallCord) { + absl::Cord cord("Hello"); + const char* data = cord.Flatten().data(); + EXPECT_DEATH(EXPECT_EQ(data[5], 0), MASanDeathExpr()); +} + +TEST(CordSanitizerTest, SanitizesCordOnSetSSOValue) { + absl::Cord cord("String that is too big to be an SSO value"); + cord = "Hello"; + const char* data = cord.Flatten().data(); + EXPECT_DEATH(EXPECT_EQ(data[5], 0), MASanDeathExpr()); +} + +TEST(CordSanitizerTest, SanitizesCordOnCopyCtor) { + absl::Cord src("hello"); + absl::Cord dst(src); + const char* data = dst.Flatten().data(); + EXPECT_DEATH(EXPECT_EQ(data[5], 0), MASanDeathExpr()); +} + +TEST(CordSanitizerTest, SanitizesCordOnMoveCtor) { + absl::Cord src("hello"); + absl::Cord dst(std::move(src)); + const char* data = dst.Flatten().data(); + EXPECT_DEATH(EXPECT_EQ(data[5], 0), MASanDeathExpr()); +} + +TEST(CordSanitizerTest, SanitizesCordOnAssign) { + absl::Cord src("hello"); + absl::Cord dst; + dst = src; + const char* data = dst.Flatten().data(); + EXPECT_DEATH(EXPECT_EQ(data[5], 0), MASanDeathExpr()); +} + +TEST(CordSanitizerTest, SanitizesCordOnMoveAssign) { + absl::Cord src("hello"); + absl::Cord dst; + dst = std::move(src); + const char* data = dst.Flatten().data(); + EXPECT_DEATH(EXPECT_EQ(data[5], 0), MASanDeathExpr()); +} + +TEST(CordSanitizerTest, SanitizesCordOnSsoAssign) { + absl::Cord src("hello"); + absl::Cord dst("String that is too big to be an SSO value"); + dst = src; + const char* data = dst.Flatten().data(); + EXPECT_DEATH(EXPECT_EQ(data[5], 0), MASanDeathExpr()); +} + +#endif // GTEST_HAS_DEATH_TEST && ABSL_INTERNAL_CORD_HAVE_SANITIZER |