snappy_benchmark.cc - third_party/snappy - Git at Google

 // Copyright 2020 Google Inc. All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 #include <cstddef>
 #include <cstdint>
 #include <string>
 #include <vector>

 #include "snappy-test.h"

 #include "benchmark/benchmark.h"

 #include "snappy-internal.h"
 #include "snappy-sinksource.h"
 #include "snappy.h"
 #include "snappy_test_data.h"

 namespace snappy {

 namespace {

 void BM_UFlat(benchmark::State& state) {
   // Pick file to process based on state.range(0).
   int file_index = state.range(0);

   CHECK_GE(file_index, 0);
   CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
   std::string contents =
       ReadTestDataFile(kTestDataFiles[file_index].filename,
                        kTestDataFiles[file_index].size_limit);

   std::string zcontents;
   snappy::Compress(contents.data(), contents.size(), &zcontents);
   char* dst = new char[contents.size()];

   for (auto s : state) {
     CHECK(snappy::RawUncompress(zcontents.data(), zcontents.size(), dst));
     benchmark::DoNotOptimize(dst);
   }
   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
                           static_cast<int64_t>(contents.size()));
   state.SetLabel(kTestDataFiles[file_index].label);

   delete[] dst;
 }
 BENCHMARK(BM_UFlat)->DenseRange(0, ARRAYSIZE(kTestDataFiles) - 1);

 struct SourceFiles {
   SourceFiles() {
     for (int i = 0; i < kFiles; i++) {
       std::string contents = ReadTestDataFile(kTestDataFiles[i].filename,
                                               kTestDataFiles[i].size_limit);
       max_size = std::max(max_size, contents.size());
       sizes[i] = contents.size();
       snappy::Compress(contents.data(), contents.size(), &zcontents[i]);
     }
   }
   static constexpr int kFiles = ARRAYSIZE(kTestDataFiles);
   std::string zcontents[kFiles];
   size_t sizes[kFiles];
   size_t max_size = 0;
 };

 void BM_UFlatMedley(benchmark::State& state) {
   static const SourceFiles* const source = new SourceFiles();

   std::vector<char> dst(source->max_size);

   for (auto s : state) {
     for (int i = 0; i < SourceFiles::kFiles; i++) {
       CHECK(snappy::RawUncompress(source->zcontents[i].data(),
                                   source->zcontents[i].size(), dst.data()));
       benchmark::DoNotOptimize(dst);
     }
   }

   int64_t source_sizes = 0;
   for (int i = 0; i < SourceFiles::kFiles; i++) {
     source_sizes += static_cast<int64_t>(source->sizes[i]);
   }
   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
                           source_sizes);
 }
 BENCHMARK(BM_UFlatMedley);

 void BM_UValidate(benchmark::State& state) {
   // Pick file to process based on state.range(0).
   int file_index = state.range(0);

   CHECK_GE(file_index, 0);
   CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
   std::string contents =
       ReadTestDataFile(kTestDataFiles[file_index].filename,
                        kTestDataFiles[file_index].size_limit);

   std::string zcontents;
   snappy::Compress(contents.data(), contents.size(), &zcontents);

   for (auto s : state) {
     CHECK(snappy::IsValidCompressedBuffer(zcontents.data(), zcontents.size()));
   }
   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
                           static_cast<int64_t>(contents.size()));
   state.SetLabel(kTestDataFiles[file_index].label);
 }
 BENCHMARK(BM_UValidate)->DenseRange(0, ARRAYSIZE(kTestDataFiles) - 1);

 void BM_UValidateMedley(benchmark::State& state) {
   static const SourceFiles* const source = new SourceFiles();

   for (auto s : state) {
     for (int i = 0; i < SourceFiles::kFiles; i++) {
       CHECK(snappy::IsValidCompressedBuffer(source->zcontents[i].data(),
                                             source->zcontents[i].size()));
     }
   }

   int64_t source_sizes = 0;
   for (int i = 0; i < SourceFiles::kFiles; i++) {
     source_sizes += static_cast<int64_t>(source->sizes[i]);
   }
   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
                           source_sizes);
 }
 BENCHMARK(BM_UValidateMedley);

 void BM_UIOVecSource(benchmark::State& state) {
   // Pick file to process based on state.range(0).
   int file_index = state.range(0);

   CHECK_GE(file_index, 0);
   CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
   std::string contents =
       ReadTestDataFile(kTestDataFiles[file_index].filename,
                        kTestDataFiles[file_index].size_limit);

   // Create `iovec`s of the `contents`.
   const int kNumEntries = 10;
   struct iovec iov[kNumEntries];
   size_t used_so_far = 0;
   for (int i = 0; i < kNumEntries; ++i) {
     iov[i].iov_base = const_cast<char*>(contents.data()) + used_so_far;
     if (used_so_far == contents.size()) {
       iov[i].iov_len = 0;
       continue;
     }
     if (i == kNumEntries - 1) {
       iov[i].iov_len = contents.size() - used_so_far;
     } else {
       iov[i].iov_len = contents.size() / kNumEntries;
     }
     used_so_far += iov[i].iov_len;
   }

   char* dst = new char[snappy::MaxCompressedLength(contents.size())];
   size_t zsize = 0;
   for (auto s : state) {
     snappy::RawCompressFromIOVec(iov, contents.size(), dst, &zsize);
     benchmark::DoNotOptimize(iov);
   }
   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
                           static_cast<int64_t>(contents.size()));
   const double compression_ratio =
       static_cast<double>(zsize) / std::max<size_t>(1, contents.size());
   state.SetLabel(StrFormat("%s (%.2f %%)", kTestDataFiles[file_index].label,
                            100.0 * compression_ratio));
   VLOG(0) << StrFormat("compression for %s: %d -> %d bytes",
                        kTestDataFiles[file_index].label, contents.size(),
                        zsize);

   delete[] dst;
 }
 BENCHMARK(BM_UIOVecSource)->DenseRange(0, ARRAYSIZE(kTestDataFiles) - 1);

 void BM_UIOVecSink(benchmark::State& state) {
   // Pick file to process based on state.range(0).
   int file_index = state.range(0);

   CHECK_GE(file_index, 0);
   CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
   std::string contents =
       ReadTestDataFile(kTestDataFiles[file_index].filename,
                        kTestDataFiles[file_index].size_limit);

   std::string zcontents;
   snappy::Compress(contents.data(), contents.size(), &zcontents);

   // Uncompress into an iovec containing ten entries.
   const int kNumEntries = 10;
   struct iovec iov[kNumEntries];
   char *dst = new char[contents.size()];
   size_t used_so_far = 0;
   for (int i = 0; i < kNumEntries; ++i) {
     iov[i].iov_base = dst + used_so_far;
     if (used_so_far == contents.size()) {
       iov[i].iov_len = 0;
       continue;
     }

     if (i == kNumEntries - 1) {
       iov[i].iov_len = contents.size() - used_so_far;
     } else {
       iov[i].iov_len = contents.size() / kNumEntries;
     }
     used_so_far += iov[i].iov_len;
   }

   for (auto s : state) {
     CHECK(snappy::RawUncompressToIOVec(zcontents.data(), zcontents.size(), iov,
                                        kNumEntries));
     benchmark::DoNotOptimize(iov);
   }
   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
                           static_cast<int64_t>(contents.size()));
   state.SetLabel(kTestDataFiles[file_index].label);

   delete[] dst;
 }
 BENCHMARK(BM_UIOVecSink)->DenseRange(0, 4);

 void BM_UFlatSink(benchmark::State& state) {
   // Pick file to process based on state.range(0).
   int file_index = state.range(0);

   CHECK_GE(file_index, 0);
   CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
   std::string contents =
       ReadTestDataFile(kTestDataFiles[file_index].filename,
                        kTestDataFiles[file_index].size_limit);

   std::string zcontents;
   snappy::Compress(contents.data(), contents.size(), &zcontents);
   char* dst = new char[contents.size()];

   for (auto s : state) {
     snappy::ByteArraySource source(zcontents.data(), zcontents.size());
     snappy::UncheckedByteArraySink sink(dst);
     CHECK(snappy::Uncompress(&source, &sink));
     benchmark::DoNotOptimize(sink);
   }
   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
                           static_cast<int64_t>(contents.size()));
   state.SetLabel(kTestDataFiles[file_index].label);

   std::string s(dst, contents.size());
   CHECK_EQ(contents, s);

   delete[] dst;
 }

 BENCHMARK(BM_UFlatSink)->DenseRange(0, ARRAYSIZE(kTestDataFiles) - 1);

 void BM_ZFlat(benchmark::State& state) {
   // Pick file to process based on state.range(0).
   int file_index = state.range(0);

   CHECK_GE(file_index, 0);
   CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
   std::string contents =
       ReadTestDataFile(kTestDataFiles[file_index].filename,
                        kTestDataFiles[file_index].size_limit);
   char* dst = new char[snappy::MaxCompressedLength(contents.size())];

   size_t zsize = 0;
   for (auto s : state) {
     snappy::RawCompress(contents.data(), contents.size(), dst, &zsize);
     benchmark::DoNotOptimize(dst);
   }
   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
                           static_cast<int64_t>(contents.size()));
   const double compression_ratio =
       static_cast<double>(zsize) / std::max<size_t>(1, contents.size());
   state.SetLabel(StrFormat("%s (%.2f %%)", kTestDataFiles[file_index].label,
                            100.0 * compression_ratio));
   VLOG(0) << StrFormat("compression for %s: %d -> %d bytes",
                        kTestDataFiles[file_index].label, contents.size(),
                        zsize);
   delete[] dst;
 }
 BENCHMARK(BM_ZFlat)->DenseRange(0, ARRAYSIZE(kTestDataFiles) - 1);

 void BM_ZFlatAll(benchmark::State& state) {
   const int num_files = ARRAYSIZE(kTestDataFiles);

   std::vector<std::string> contents(num_files);
   std::vector<char*> dst(num_files);

   int64_t total_contents_size = 0;
   for (int i = 0; i < num_files; ++i) {
     contents[i] = ReadTestDataFile(kTestDataFiles[i].filename,
                                    kTestDataFiles[i].size_limit);
     dst[i] = new char[snappy::MaxCompressedLength(contents[i].size())];
     total_contents_size += contents[i].size();
   }

   size_t zsize = 0;
   for (auto s : state) {
     for (int i = 0; i < num_files; ++i) {
       snappy::RawCompress(contents[i].data(), contents[i].size(), dst[i],
                           &zsize);
       benchmark::DoNotOptimize(dst);
     }
   }

   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
                           total_contents_size);

   for (char* dst_item : dst) {
     delete[] dst_item;
   }
   state.SetLabel(StrFormat("%d kTestDataFiles", num_files));
 }
 BENCHMARK(BM_ZFlatAll);

 void BM_ZFlatIncreasingTableSize(benchmark::State& state) {
   CHECK_GT(ARRAYSIZE(kTestDataFiles), 0);
   const std::string base_content = ReadTestDataFile(
       kTestDataFiles[0].filename, kTestDataFiles[0].size_limit);

   std::vector<std::string> contents;
   std::vector<char*> dst;
   int64_t total_contents_size = 0;
   for (int table_bits = kMinHashTableBits; table_bits <= kMaxHashTableBits;
        ++table_bits) {
     std::string content = base_content;
     content.resize(1 << table_bits);
     dst.push_back(new char[snappy::MaxCompressedLength(content.size())]);
     total_contents_size += content.size();
     contents.push_back(std::move(content));
   }

   size_t zsize = 0;
   for (auto s : state) {
     for (size_t i = 0; i < contents.size(); ++i) {
       snappy::RawCompress(contents[i].data(), contents[i].size(), dst[i],
                           &zsize);
       benchmark::DoNotOptimize(dst);
     }
   }

   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
                           total_contents_size);

   for (char* dst_item : dst) {
     delete[] dst_item;
   }
   state.SetLabel(StrFormat("%d tables", contents.size()));
 }
 BENCHMARK(BM_ZFlatIncreasingTableSize);

 }  // namespace

 }  // namespace snappy
	// Copyright 2020 Google Inc. All Rights Reserved.
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are
	// met:
	//
	// * Redistributions of source code must retain the above copyright
	// notice, this list of conditions and the following disclaimer.
	// * Redistributions in binary form must reproduce the above
	// copyright notice, this list of conditions and the following disclaimer
	// in the documentation and/or other materials provided with the
	// distribution.
	// * Neither the name of Google Inc. nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	#include <cstddef>
	#include <cstdint>
	#include <string>
	#include <vector>

	#include "snappy-test.h"

	#include "benchmark/benchmark.h"

	#include "snappy-internal.h"
	#include "snappy-sinksource.h"
	#include "snappy.h"
	#include "snappy_test_data.h"

	namespace snappy {

	namespace {

	void BM_UFlat(benchmark::State& state) {
	// Pick file to process based on state.range(0).
	int file_index = state.range(0);

	CHECK_GE(file_index, 0);
	CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
	std::string contents =
	ReadTestDataFile(kTestDataFiles[file_index].filename,
	kTestDataFiles[file_index].size_limit);

	std::string zcontents;
	snappy::Compress(contents.data(), contents.size(), &zcontents);
	char* dst = new char[contents.size()];

	for (auto s : state) {
	CHECK(snappy::RawUncompress(zcontents.data(), zcontents.size(), dst));
	benchmark::DoNotOptimize(dst);
	}
	state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
	static_cast<int64_t>(contents.size()));
	state.SetLabel(kTestDataFiles[file_index].label);

	delete[] dst;
	}
	BENCHMARK(BM_UFlat)->DenseRange(0, ARRAYSIZE(kTestDataFiles) - 1);

	struct SourceFiles {
	SourceFiles() {
	for (int i = 0; i < kFiles; i++) {
	std::string contents = ReadTestDataFile(kTestDataFiles[i].filename,
	kTestDataFiles[i].size_limit);
	max_size = std::max(max_size, contents.size());
	sizes[i] = contents.size();
	snappy::Compress(contents.data(), contents.size(), &zcontents[i]);
	}
	}
	static constexpr int kFiles = ARRAYSIZE(kTestDataFiles);
	std::string zcontents[kFiles];
	size_t sizes[kFiles];
	size_t max_size = 0;
	};

	void BM_UFlatMedley(benchmark::State& state) {
	static const SourceFiles* const source = new SourceFiles();

	std::vector<char> dst(source->max_size);

	for (auto s : state) {
	for (int i = 0; i < SourceFiles::kFiles; i++) {
	CHECK(snappy::RawUncompress(source->zcontents[i].data(),
	source->zcontents[i].size(), dst.data()));
	benchmark::DoNotOptimize(dst);
	}
	}

	int64_t source_sizes = 0;
	for (int i = 0; i < SourceFiles::kFiles; i++) {
	source_sizes += static_cast<int64_t>(source->sizes[i]);
	}
	state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
	source_sizes);
	}
	BENCHMARK(BM_UFlatMedley);

	void BM_UValidate(benchmark::State& state) {
	// Pick file to process based on state.range(0).
	int file_index = state.range(0);

	CHECK_GE(file_index, 0);
	CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
	std::string contents =
	ReadTestDataFile(kTestDataFiles[file_index].filename,
	kTestDataFiles[file_index].size_limit);

	std::string zcontents;
	snappy::Compress(contents.data(), contents.size(), &zcontents);

	for (auto s : state) {
	CHECK(snappy::IsValidCompressedBuffer(zcontents.data(), zcontents.size()));
	}
	state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
	static_cast<int64_t>(contents.size()));
	state.SetLabel(kTestDataFiles[file_index].label);
	}
	BENCHMARK(BM_UValidate)->DenseRange(0, ARRAYSIZE(kTestDataFiles) - 1);

	void BM_UValidateMedley(benchmark::State& state) {
	static const SourceFiles* const source = new SourceFiles();

	for (auto s : state) {
	for (int i = 0; i < SourceFiles::kFiles; i++) {
	CHECK(snappy::IsValidCompressedBuffer(source->zcontents[i].data(),
	source->zcontents[i].size()));
	}
	}

	int64_t source_sizes = 0;
	for (int i = 0; i < SourceFiles::kFiles; i++) {
	source_sizes += static_cast<int64_t>(source->sizes[i]);
	}
	state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
	source_sizes);
	}
	BENCHMARK(BM_UValidateMedley);

	void BM_UIOVecSource(benchmark::State& state) {
	// Pick file to process based on state.range(0).
	int file_index = state.range(0);

	CHECK_GE(file_index, 0);
	CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
	std::string contents =
	ReadTestDataFile(kTestDataFiles[file_index].filename,
	kTestDataFiles[file_index].size_limit);

	// Create `iovec`s of the `contents`.
	const int kNumEntries = 10;
	struct iovec iov[kNumEntries];
	size_t used_so_far = 0;
	for (int i = 0; i < kNumEntries; ++i) {
	iov[i].iov_base = const_cast<char*>(contents.data()) + used_so_far;
	if (used_so_far == contents.size()) {
	iov[i].iov_len = 0;
	continue;
	}
	if (i == kNumEntries - 1) {
	iov[i].iov_len = contents.size() - used_so_far;
	} else {
	iov[i].iov_len = contents.size() / kNumEntries;
	}
	used_so_far += iov[i].iov_len;
	}

	char* dst = new char[snappy::MaxCompressedLength(contents.size())];
	size_t zsize = 0;
	for (auto s : state) {
	snappy::RawCompressFromIOVec(iov, contents.size(), dst, &zsize);
	benchmark::DoNotOptimize(iov);
	}
	state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
	static_cast<int64_t>(contents.size()));
	const double compression_ratio =
	static_cast<double>(zsize) / std::max<size_t>(1, contents.size());
	state.SetLabel(StrFormat("%s (%.2f %%)", kTestDataFiles[file_index].label,
	100.0 * compression_ratio));
	VLOG(0) << StrFormat("compression for %s: %d -> %d bytes",
	kTestDataFiles[file_index].label, contents.size(),
	zsize);

	delete[] dst;
	}
	BENCHMARK(BM_UIOVecSource)->DenseRange(0, ARRAYSIZE(kTestDataFiles) - 1);

	void BM_UIOVecSink(benchmark::State& state) {
	// Pick file to process based on state.range(0).
	int file_index = state.range(0);

	CHECK_GE(file_index, 0);
	CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
	std::string contents =
	ReadTestDataFile(kTestDataFiles[file_index].filename,
	kTestDataFiles[file_index].size_limit);

	std::string zcontents;
	snappy::Compress(contents.data(), contents.size(), &zcontents);

	// Uncompress into an iovec containing ten entries.
	const int kNumEntries = 10;
	struct iovec iov[kNumEntries];
	char *dst = new char[contents.size()];
	size_t used_so_far = 0;
	for (int i = 0; i < kNumEntries; ++i) {
	iov[i].iov_base = dst + used_so_far;
	if (used_so_far == contents.size()) {
	iov[i].iov_len = 0;
	continue;
	}

	if (i == kNumEntries - 1) {
	iov[i].iov_len = contents.size() - used_so_far;
	} else {
	iov[i].iov_len = contents.size() / kNumEntries;
	}
	used_so_far += iov[i].iov_len;
	}

	for (auto s : state) {
	CHECK(snappy::RawUncompressToIOVec(zcontents.data(), zcontents.size(), iov,
	kNumEntries));
	benchmark::DoNotOptimize(iov);
	}
	state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
	static_cast<int64_t>(contents.size()));
	state.SetLabel(kTestDataFiles[file_index].label);

	delete[] dst;
	}
	BENCHMARK(BM_UIOVecSink)->DenseRange(0, 4);

	void BM_UFlatSink(benchmark::State& state) {
	// Pick file to process based on state.range(0).
	int file_index = state.range(0);

	CHECK_GE(file_index, 0);
	CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
	std::string contents =
	ReadTestDataFile(kTestDataFiles[file_index].filename,
	kTestDataFiles[file_index].size_limit);

	std::string zcontents;
	snappy::Compress(contents.data(), contents.size(), &zcontents);
	char* dst = new char[contents.size()];

	for (auto s : state) {
	snappy::ByteArraySource source(zcontents.data(), zcontents.size());
	snappy::UncheckedByteArraySink sink(dst);
	CHECK(snappy::Uncompress(&source, &sink));
	benchmark::DoNotOptimize(sink);
	}
	state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
	static_cast<int64_t>(contents.size()));
	state.SetLabel(kTestDataFiles[file_index].label);

	std::string s(dst, contents.size());
	CHECK_EQ(contents, s);

	delete[] dst;
	}

	BENCHMARK(BM_UFlatSink)->DenseRange(0, ARRAYSIZE(kTestDataFiles) - 1);

	void BM_ZFlat(benchmark::State& state) {
	// Pick file to process based on state.range(0).
	int file_index = state.range(0);

	CHECK_GE(file_index, 0);
	CHECK_LT(file_index, ARRAYSIZE(kTestDataFiles));
	std::string contents =
	ReadTestDataFile(kTestDataFiles[file_index].filename,
	kTestDataFiles[file_index].size_limit);
	char* dst = new char[snappy::MaxCompressedLength(contents.size())];

	size_t zsize = 0;
	for (auto s : state) {
	snappy::RawCompress(contents.data(), contents.size(), dst, &zsize);
	benchmark::DoNotOptimize(dst);
	}
	state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
	static_cast<int64_t>(contents.size()));
	const double compression_ratio =
	static_cast<double>(zsize) / std::max<size_t>(1, contents.size());
	state.SetLabel(StrFormat("%s (%.2f %%)", kTestDataFiles[file_index].label,
	100.0 * compression_ratio));
	VLOG(0) << StrFormat("compression for %s: %d -> %d bytes",
	kTestDataFiles[file_index].label, contents.size(),
	zsize);
	delete[] dst;
	}
	BENCHMARK(BM_ZFlat)->DenseRange(0, ARRAYSIZE(kTestDataFiles) - 1);

	void BM_ZFlatAll(benchmark::State& state) {
	const int num_files = ARRAYSIZE(kTestDataFiles);

	std::vector<std::string> contents(num_files);
	std::vector<char*> dst(num_files);

	int64_t total_contents_size = 0;
	for (int i = 0; i < num_files; ++i) {
	contents[i] = ReadTestDataFile(kTestDataFiles[i].filename,
	kTestDataFiles[i].size_limit);
	dst[i] = new char[snappy::MaxCompressedLength(contents[i].size())];
	total_contents_size += contents[i].size();
	}

	size_t zsize = 0;
	for (auto s : state) {
	for (int i = 0; i < num_files; ++i) {
	snappy::RawCompress(contents[i].data(), contents[i].size(), dst[i],
	&zsize);
	benchmark::DoNotOptimize(dst);
	}
	}

	state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
	total_contents_size);

	for (char* dst_item : dst) {
	delete[] dst_item;
	}
	state.SetLabel(StrFormat("%d kTestDataFiles", num_files));
	}
	BENCHMARK(BM_ZFlatAll);

	void BM_ZFlatIncreasingTableSize(benchmark::State& state) {
	CHECK_GT(ARRAYSIZE(kTestDataFiles), 0);
	const std::string base_content = ReadTestDataFile(
	kTestDataFiles[0].filename, kTestDataFiles[0].size_limit);

	std::vector<std::string> contents;
	std::vector<char*> dst;
	int64_t total_contents_size = 0;
	for (int table_bits = kMinHashTableBits; table_bits <= kMaxHashTableBits;
	++table_bits) {
	std::string content = base_content;
	content.resize(1 << table_bits);
	dst.push_back(new char[snappy::MaxCompressedLength(content.size())]);
	total_contents_size += content.size();
	contents.push_back(std::move(content));
	}

	size_t zsize = 0;
	for (auto s : state) {
	for (size_t i = 0; i < contents.size(); ++i) {
	snappy::RawCompress(contents[i].data(), contents[i].size(), dst[i],
	&zsize);
	benchmark::DoNotOptimize(dst);
	}
	}

	state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
	total_contents_size);

	for (char* dst_item : dst) {
	delete[] dst_item;
	}
	state.SetLabel(StrFormat("%d tables", contents.size()));
	}
	BENCHMARK(BM_ZFlatIncreasingTableSize);

	} // namespace

	} // namespace snappy