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Diffstat (limited to 'abseil-cpp/absl/strings/internal/cord_rep_btree_reader_test.cc')
-rw-r--r-- | abseil-cpp/absl/strings/internal/cord_rep_btree_reader_test.cc | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/abseil-cpp/absl/strings/internal/cord_rep_btree_reader_test.cc b/abseil-cpp/absl/strings/internal/cord_rep_btree_reader_test.cc new file mode 100644 index 0000000..b4cdd8e --- /dev/null +++ b/abseil-cpp/absl/strings/internal/cord_rep_btree_reader_test.cc @@ -0,0 +1,293 @@ +// Copyright 2021 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/internal/cord_rep_btree_reader.h" + +#include <iostream> +#include <random> +#include <string> +#include <vector> + +#include "gmock/gmock.h" +#include "gtest/gtest.h" +#include "absl/base/config.h" +#include "absl/base/internal/raw_logging.h" +#include "absl/strings/cord.h" +#include "absl/strings/internal/cord_internal.h" +#include "absl/strings/internal/cord_rep_btree.h" +#include "absl/strings/internal/cord_rep_test_util.h" +#include "absl/strings/string_view.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace cord_internal { +namespace { + +using ::testing::Eq; +using ::testing::IsEmpty; +using ::testing::Ne; +using ::testing::Not; + +using ::absl::cordrep_testing::CordRepBtreeFromFlats; +using ::absl::cordrep_testing::MakeFlat; +using ::absl::cordrep_testing::CordToString; +using ::absl::cordrep_testing::CreateFlatsFromString; +using ::absl::cordrep_testing::CreateRandomString; + +using ReadResult = CordRepBtreeReader::ReadResult; + +TEST(CordRepBtreeReaderTest, Next) { + constexpr size_t kChars = 3; + const size_t cap = CordRepBtree::kMaxCapacity; + size_t counts[] = {1, 2, cap, cap * cap, cap * cap + 1, cap * cap * 2 + 17}; + + for (size_t count : counts) { + std::string data = CreateRandomString(count * kChars); + std::vector<CordRep*> flats = CreateFlatsFromString(data, kChars); + CordRepBtree* node = CordRepBtreeFromFlats(flats); + + CordRepBtreeReader reader; + size_t remaining = data.length(); + absl::string_view chunk = reader.Init(node); + EXPECT_THAT(chunk, Eq(data.substr(0, chunk.length()))); + + remaining -= chunk.length(); + EXPECT_THAT(reader.remaining(), Eq(remaining)); + + while (remaining > 0) { + const size_t offset = data.length() - remaining; + chunk = reader.Next(); + EXPECT_THAT(chunk, Eq(data.substr(offset, chunk.length()))); + + remaining -= chunk.length(); + EXPECT_THAT(reader.remaining(), Eq(remaining)); + } + + EXPECT_THAT(reader.remaining(), Eq(0u)); + + // Verify trying to read beyond EOF returns empty string_view + EXPECT_THAT(reader.Next(), testing::IsEmpty()); + + CordRep::Unref(node); + } +} + +TEST(CordRepBtreeReaderTest, Skip) { + constexpr size_t kChars = 3; + const size_t cap = CordRepBtree::kMaxCapacity; + size_t counts[] = {1, 2, cap, cap * cap, cap * cap + 1, cap * cap * 2 + 17}; + + for (size_t count : counts) { + std::string data = CreateRandomString(count * kChars); + std::vector<CordRep*> flats = CreateFlatsFromString(data, kChars); + CordRepBtree* node = CordRepBtreeFromFlats(flats); + + for (size_t skip1 = 0; skip1 < data.length() - kChars; ++skip1) { + for (size_t skip2 = 0; skip2 < data.length() - kChars; ++skip2) { + CordRepBtreeReader reader; + size_t remaining = data.length(); + absl::string_view chunk = reader.Init(node); + remaining -= chunk.length(); + + chunk = reader.Skip(skip1); + size_t offset = data.length() - remaining; + ASSERT_THAT(chunk, Eq(data.substr(offset + skip1, chunk.length()))); + remaining -= chunk.length() + skip1; + ASSERT_THAT(reader.remaining(), Eq(remaining)); + + if (remaining == 0) continue; + + size_t skip = std::min(remaining - 1, skip2); + chunk = reader.Skip(skip); + offset = data.length() - remaining; + ASSERT_THAT(chunk, Eq(data.substr(offset + skip, chunk.length()))); + } + } + + CordRep::Unref(node); + } +} + +TEST(CordRepBtreeReaderTest, SkipBeyondLength) { + CordRepBtree* tree = CordRepBtree::Create(MakeFlat("abc")); + tree = CordRepBtree::Append(tree, MakeFlat("def")); + CordRepBtreeReader reader; + reader.Init(tree); + EXPECT_THAT(reader.Skip(100), IsEmpty()); + EXPECT_THAT(reader.remaining(), Eq(0u)); + CordRep::Unref(tree); +} + +TEST(CordRepBtreeReaderTest, Seek) { + constexpr size_t kChars = 3; + const size_t cap = CordRepBtree::kMaxCapacity; + size_t counts[] = {1, 2, cap, cap * cap, cap * cap + 1, cap * cap * 2 + 17}; + + for (size_t count : counts) { + std::string data = CreateRandomString(count * kChars); + std::vector<CordRep*> flats = CreateFlatsFromString(data, kChars); + CordRepBtree* node = CordRepBtreeFromFlats(flats); + + for (size_t seek = 0; seek < data.length() - 1; ++seek) { + CordRepBtreeReader reader; + reader.Init(node); + absl::string_view chunk = reader.Seek(seek); + ASSERT_THAT(chunk, Not(IsEmpty())); + ASSERT_THAT(chunk, Eq(data.substr(seek, chunk.length()))); + ASSERT_THAT(reader.remaining(), + Eq(data.length() - seek - chunk.length())); + } + + CordRep::Unref(node); + } +} + +TEST(CordRepBtreeReaderTest, SeekBeyondLength) { + CordRepBtree* tree = CordRepBtree::Create(MakeFlat("abc")); + tree = CordRepBtree::Append(tree, MakeFlat("def")); + CordRepBtreeReader reader; + reader.Init(tree); + EXPECT_THAT(reader.Seek(6), IsEmpty()); + EXPECT_THAT(reader.remaining(), Eq(0u)); + EXPECT_THAT(reader.Seek(100), IsEmpty()); + EXPECT_THAT(reader.remaining(), Eq(0u)); + CordRep::Unref(tree); +} + +TEST(CordRepBtreeReaderTest, Read) { + std::string data = "abcdefghijklmno"; + std::vector<CordRep*> flats = CreateFlatsFromString(data, 5); + CordRepBtree* node = CordRepBtreeFromFlats(flats); + + CordRep* tree; + CordRepBtreeReader reader; + absl::string_view chunk; + + // Read zero bytes + chunk = reader.Init(node); + chunk = reader.Read(0, chunk.length(), tree); + EXPECT_THAT(tree, Eq(nullptr)); + EXPECT_THAT(chunk, Eq("abcde")); + EXPECT_THAT(reader.remaining(), Eq(10u)); + EXPECT_THAT(reader.Next(), Eq("fghij")); + + // Read in full + chunk = reader.Init(node); + chunk = reader.Read(15, chunk.length(), tree); + EXPECT_THAT(tree, Ne(nullptr)); + EXPECT_THAT(CordToString(tree), Eq("abcdefghijklmno")); + EXPECT_THAT(chunk, Eq("")); + EXPECT_THAT(reader.remaining(), Eq(0u)); + CordRep::Unref(tree); + + // Read < chunk bytes + chunk = reader.Init(node); + chunk = reader.Read(3, chunk.length(), tree); + ASSERT_THAT(tree, Ne(nullptr)); + EXPECT_THAT(CordToString(tree), Eq("abc")); + EXPECT_THAT(chunk, Eq("de")); + EXPECT_THAT(reader.remaining(), Eq(10u)); + EXPECT_THAT(reader.Next(), Eq("fghij")); + CordRep::Unref(tree); + + // Read < chunk bytes at offset + chunk = reader.Init(node); + chunk = reader.Read(2, chunk.length() - 2, tree); + ASSERT_THAT(tree, Ne(nullptr)); + EXPECT_THAT(CordToString(tree), Eq("cd")); + EXPECT_THAT(chunk, Eq("e")); + EXPECT_THAT(reader.remaining(), Eq(10u)); + EXPECT_THAT(reader.Next(), Eq("fghij")); + CordRep::Unref(tree); + + // Read from consumed chunk + chunk = reader.Init(node); + chunk = reader.Read(3, 0, tree); + ASSERT_THAT(tree, Ne(nullptr)); + EXPECT_THAT(CordToString(tree), Eq("fgh")); + EXPECT_THAT(chunk, Eq("ij")); + EXPECT_THAT(reader.remaining(), Eq(5u)); + EXPECT_THAT(reader.Next(), Eq("klmno")); + CordRep::Unref(tree); + + // Read across chunks + chunk = reader.Init(node); + chunk = reader.Read(12, chunk.length() - 2, tree); + ASSERT_THAT(tree, Ne(nullptr)); + EXPECT_THAT(CordToString(tree), Eq("cdefghijklmn")); + EXPECT_THAT(chunk, Eq("o")); + EXPECT_THAT(reader.remaining(), Eq(0u)); + CordRep::Unref(tree); + + // Read across chunks landing on exact edge boundary + chunk = reader.Init(node); + chunk = reader.Read(10 - 2, chunk.length() - 2, tree); + ASSERT_THAT(tree, Ne(nullptr)); + EXPECT_THAT(CordToString(tree), Eq("cdefghij")); + EXPECT_THAT(chunk, Eq("klmno")); + EXPECT_THAT(reader.remaining(), Eq(0u)); + CordRep::Unref(tree); + + CordRep::Unref(node); +} + +TEST(CordRepBtreeReaderTest, ReadExhaustive) { + constexpr size_t kChars = 3; + const size_t cap = CordRepBtree::kMaxCapacity; + size_t counts[] = {1, 2, cap, cap * cap + 1, cap * cap * cap * 2 + 17}; + + for (size_t count : counts) { + std::string data = CreateRandomString(count * kChars); + std::vector<CordRep*> flats = CreateFlatsFromString(data, kChars); + CordRepBtree* node = CordRepBtreeFromFlats(flats); + + for (size_t read_size : {kChars - 1, kChars, kChars + 7, cap * cap}) { + CordRepBtreeReader reader; + absl::string_view chunk = reader.Init(node); + + // `consumed` tracks the end of last consumed chunk which is the start of + // the next chunk: we always read with `chunk_size = chunk.length()`. + size_t consumed = 0; + size_t remaining = data.length(); + while (remaining > 0) { + CordRep* tree; + size_t n = (std::min)(remaining, read_size); + chunk = reader.Read(n, chunk.length(), tree); + EXPECT_THAT(tree, Ne(nullptr)); + if (tree) { + EXPECT_THAT(CordToString(tree), Eq(data.substr(consumed, n))); + CordRep::Unref(tree); + } + + consumed += n; + remaining -= n; + EXPECT_THAT(reader.remaining(), Eq(remaining - chunk.length())); + + if (remaining > 0) { + ASSERT_FALSE(chunk.empty()); + ASSERT_THAT(chunk, Eq(data.substr(consumed, chunk.length()))); + } else { + ASSERT_TRUE(chunk.empty()) << chunk; + } + } + } + + CordRep::Unref(node); + } +} + +} // namespace +} // namespace cord_internal +ABSL_NAMESPACE_END +} // namespace absl |