diff options
| -rw-r--r-- | absl/hash/internal/spy_hash_state.h | 24 | ||||
| -rw-r--r-- | absl/strings/BUILD.bazel | 1 | ||||
| -rw-r--r-- | absl/strings/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | absl/strings/cord_test.cc | 21 |
4 files changed, 35 insertions, 12 deletions
diff --git a/absl/hash/internal/spy_hash_state.h b/absl/hash/internal/spy_hash_state.h index 09728266..357c301c 100644 --- a/absl/hash/internal/spy_hash_state.h +++ b/absl/hash/internal/spy_hash_state.h @@ -149,20 +149,20 @@ class SpyHashStateImpl : public HashStateBase<SpyHashStateImpl<T>> { const unsigned char* begin, size_t size) { const size_t large_chunk_stride = PiecewiseChunkSize(); - if (size > large_chunk_stride) { - // Combining a large contiguous buffer must have the same effect as - // doing it piecewise by the stride length, followed by the (possibly - // empty) remainder. - while (size >= large_chunk_stride) { - hash_state = SpyHashStateImpl::combine_contiguous( - std::move(hash_state), begin, large_chunk_stride); - begin += large_chunk_stride; - size -= large_chunk_stride; - } + // Combining a large contiguous buffer must have the same effect as + // doing it piecewise by the stride length, followed by the (possibly + // empty) remainder. + while (size > large_chunk_stride) { + hash_state = SpyHashStateImpl::combine_contiguous( + std::move(hash_state), begin, large_chunk_stride); + begin += large_chunk_stride; + size -= large_chunk_stride; } - hash_state.hash_representation_.emplace_back( - reinterpret_cast<const char*>(begin), size); + if (size > 0) { + hash_state.hash_representation_.emplace_back( + reinterpret_cast<const char*>(begin), size); + } return hash_state; } diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel index 8e8371b3..ed2ab04f 100644 --- a/absl/strings/BUILD.bazel +++ b/absl/strings/BUILD.bazel @@ -918,6 +918,7 @@ cc_test( "//absl/container:fixed_array", "//absl/functional:function_ref", "//absl/hash", + "//absl/hash:hash_testing", "//absl/log", "//absl/log:check", "//absl/random", diff --git a/absl/strings/CMakeLists.txt b/absl/strings/CMakeLists.txt index 1b245362..ce9c5e46 100644 --- a/absl/strings/CMakeLists.txt +++ b/absl/strings/CMakeLists.txt @@ -1072,6 +1072,7 @@ absl_cc_test( absl::fixed_array absl::function_ref absl::hash + absl::hash_testing absl::log absl::optional absl::random_random diff --git a/absl/strings/cord_test.cc b/absl/strings/cord_test.cc index f1a5f39c..69b1a69e 100644 --- a/absl/strings/cord_test.cc +++ b/absl/strings/cord_test.cc @@ -42,6 +42,7 @@ #include "absl/container/fixed_array.h" #include "absl/functional/function_ref.h" #include "absl/hash/hash.h" +#include "absl/hash/hash_testing.h" #include "absl/log/check.h" #include "absl/log/log.h" #include "absl/random/random.h" @@ -2013,6 +2014,26 @@ TEST(CordTest, CordMemoryUsageBTree) { rep2_size); } +TEST(CordTest, TestHashFragmentation) { + // Make sure we hit these boundary cases precisely. + EXPECT_EQ(1024, absl::hash_internal::PiecewiseChunkSize()); + EXPECT_TRUE(absl::VerifyTypeImplementsAbslHashCorrectly({ + absl::Cord(), + absl::MakeFragmentedCord({std::string(600, 'a'), std::string(600, 'a')}), + absl::MakeFragmentedCord({std::string(1200, 'a')}), + absl::MakeFragmentedCord({std::string(900, 'b'), std::string(900, 'b')}), + absl::MakeFragmentedCord({std::string(1800, 'b')}), + absl::MakeFragmentedCord( + {std::string(2000, 'c'), std::string(2000, 'c')}), + absl::MakeFragmentedCord({std::string(4000, 'c')}), + absl::MakeFragmentedCord({std::string(1024, 'd')}), + absl::MakeFragmentedCord({std::string(1023, 'd'), "d"}), + absl::MakeFragmentedCord({std::string(1025, 'e')}), + absl::MakeFragmentedCord({std::string(1024, 'e'), "e"}), + absl::MakeFragmentedCord({std::string(1023, 'e'), "e", "e"}), + })); +} + // 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_P(CordTest, CordMemoryUsageInlineRep) { |