From 2074ddd6250b95ef27e72133ac9bd5ad359501a0 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Thu, 10 Dec 2015 21:32:45 -0500 Subject: [PATCH] env: add EnvMirror This is an Env implementation that mirrors all storage-related methods on two different backend Env's and verifies that they return the same results (return status and read results). This is useful for implementing a new Env and verifying its correctness. Signed-off-by: Sage Weil --- CMakeLists.txt | 1 + Makefile | 3 + include/rocksdb/env.h | 1 + include/rocksdb/utilities/env_mirror.h | 166 +++++++++++++++ src.mk | 1 + utilities/env_mirror.cc | 266 +++++++++++++++++++++++++ utilities/env_mirror_test.cc | 222 +++++++++++++++++++++ 7 files changed, 660 insertions(+) create mode 100644 include/rocksdb/utilities/env_mirror.h create mode 100644 utilities/env_mirror.cc create mode 100644 utilities/env_mirror_test.cc diff --git a/CMakeLists.txt b/CMakeLists.txt index 51749bae0..3a0068eef 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -244,6 +244,7 @@ set(SOURCES utilities/document/document_db.cc utilities/document/json_document.cc utilities/document/json_document_builder.cc + utilities/env_mirror.cc utilities/flashcache/flashcache.cc utilities/geodb/geodb_impl.cc utilities/leveldb_options/leveldb_options.cc diff --git a/Makefile b/Makefile index 2ef49fb3c..5ba47fc26 100644 --- a/Makefile +++ b/Makefile @@ -805,6 +805,9 @@ json_document_test: utilities/document/json_document_test.o $(LIBOBJECTS) $(TEST spatial_db_test: utilities/spatialdb/spatial_db_test.o $(LIBOBJECTS) $(TESTHARNESS) $(AM_LINK) +env_mirror_test: utilities/env_mirror_test.o $(LIBOBJECTS) $(TESTHARNESS) + $(AM_LINK) + ttl_test: utilities/ttl/ttl_test.o $(LIBOBJECTS) $(TESTHARNESS) $(AM_LINK) diff --git a/include/rocksdb/env.h b/include/rocksdb/env.h index 00fa52001..ebaeee6cc 100644 --- a/include/rocksdb/env.h +++ b/include/rocksdb/env.h @@ -615,6 +615,7 @@ class WritableFile { protected: friend class WritableFileWrapper; + friend class WritableFileMirror; Env::IOPriority io_priority_; }; diff --git a/include/rocksdb/utilities/env_mirror.h b/include/rocksdb/utilities/env_mirror.h new file mode 100644 index 000000000..021fbfa45 --- /dev/null +++ b/include/rocksdb/utilities/env_mirror.h @@ -0,0 +1,166 @@ +// Copyright (c) 2015, Red Hat, Inc. All rights reserved. +// This source code is licensed under the BSD-style license found in the +// LICENSE file in the root directory of this source tree. An additional grant +// of patent rights can be found in the PATENTS file in the same directory. +// Copyright (c) 2011 The LevelDB Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. See the AUTHORS file for names of contributors. +// +// MirrorEnv is an Env implementation that mirrors all file-related +// operations to two backing Env's (provided at construction time). +// Writes are mirrored. For read operations, we do the read from both +// backends and assert that the results match. +// +// This is useful when implementing a new Env and ensuring that the +// semantics and behavior are correct (in that they match that of an +// existing, stable Env, like the default POSIX one). + +#ifndef ROCKSDB_LITE + +#ifndef STORAGE_ROCKSDB_INCLUDE_UTILITIES_ENVMIRROR_H_ +#define STORAGE_ROCKSDB_INCLUDE_UTLIITIES_ENVMIRROR_H_ + +#include +#include +#include +#include "rocksdb/env.h" + +namespace rocksdb { + +class SequentialFileMirror; +class RandomAccessFileMirror; +class WritableFileMirror; + +class EnvMirror : public EnvWrapper { + Env* a_, *b_; + + public: + EnvMirror(Env* a, Env* b) : EnvWrapper(a), a_(a), b_(b) {} + + Status NewSequentialFile(const std::string& f, unique_ptr* r, + const EnvOptions& options) override; + Status NewRandomAccessFile(const std::string& f, + unique_ptr* r, + const EnvOptions& options) override; + Status NewWritableFile(const std::string& f, unique_ptr* r, + const EnvOptions& options) override; + Status ReuseWritableFile(const std::string& fname, + const std::string& old_fname, + unique_ptr* r, + const EnvOptions& options) override; + virtual Status NewDirectory(const std::string& name, + unique_ptr* result) override { + unique_ptr br; + Status as = a_->NewDirectory(name, result); + Status bs = b_->NewDirectory(name, &br); + assert(as == bs); + return as; + } + Status FileExists(const std::string& f) override { + Status as = a_->FileExists(f); + Status bs = b_->FileExists(f); + assert(as == bs); + return as; + } + Status GetChildren(const std::string& dir, + std::vector* r) override { + std::vector ar, br; + Status as = a_->GetChildren(dir, &ar); + Status bs = b_->GetChildren(dir, &br); + assert(as == bs); + std::sort(ar.begin(), ar.end()); + std::sort(br.begin(), br.end()); + if (!as.ok() || ar != br) { + assert(0 == "getchildren results don't match"); + } + *r = ar; + return as; + } + Status DeleteFile(const std::string& f) override { + Status as = a_->DeleteFile(f); + Status bs = b_->DeleteFile(f); + assert(as == bs); + return as; + } + Status CreateDir(const std::string& d) override { + Status as = a_->CreateDir(d); + Status bs = b_->CreateDir(d); + assert(as == bs); + return as; + } + Status CreateDirIfMissing(const std::string& d) override { + Status as = a_->CreateDirIfMissing(d); + Status bs = b_->CreateDirIfMissing(d); + assert(as == bs); + return as; + } + Status DeleteDir(const std::string& d) override { + Status as = a_->DeleteDir(d); + Status bs = b_->DeleteDir(d); + assert(as == bs); + return as; + } + Status GetFileSize(const std::string& f, uint64_t* s) override { + uint64_t asize, bsize; + Status as = a_->GetFileSize(f, &asize); + Status bs = b_->GetFileSize(f, &bsize); + assert(as == bs); + assert(!as.ok() || asize == bsize); + *s = asize; + return as; + } + + Status GetFileModificationTime(const std::string& fname, + uint64_t* file_mtime) override { + uint64_t amtime, bmtime; + Status as = a_->GetFileModificationTime(fname, &amtime); + Status bs = b_->GetFileModificationTime(fname, &bmtime); + assert(as == bs); + assert(!as.ok() || amtime - bmtime < 10000 || bmtime - amtime < 10000); + *file_mtime = amtime; + return as; + } + + Status RenameFile(const std::string& s, const std::string& t) override { + Status as = a_->RenameFile(s, t); + Status bs = b_->RenameFile(s, t); + assert(as == bs); + return as; + } + + Status LinkFile(const std::string& s, const std::string& t) override { + Status as = a_->LinkFile(s, t); + Status bs = b_->LinkFile(s, t); + assert(as == bs); + return as; + } + + class FileLockMirror : public FileLock { + public: + FileLock* a_, *b_; + FileLockMirror(FileLock* a, FileLock* b) : a_(a), b_(b) {} + }; + + Status LockFile(const std::string& f, FileLock** l) override { + FileLock* al, *bl; + Status as = a_->LockFile(f, &al); + Status bs = b_->LockFile(f, &bl); + assert(as == bs); + if (as.ok()) *l = new FileLockMirror(al, bl); + return as; + } + + Status UnlockFile(FileLock* l) override { + FileLockMirror* ml = static_cast(l); + Status as = a_->UnlockFile(ml->a_); + Status bs = b_->UnlockFile(ml->b_); + assert(as == bs); + return as; + } +}; + +} // namespace rocksdb + +#endif // STORAGE_ROCKSDB_INCLUDE_UTILITIES_ENVMIRROR_H_ + +#endif // ROCKSDB_LITE diff --git a/src.mk b/src.mk index 05c084ac5..9834d30d9 100644 --- a/src.mk +++ b/src.mk @@ -110,6 +110,7 @@ LIB_SOURCES = \ utilities/document/document_db.cc \ utilities/document/json_document_builder.cc \ utilities/document/json_document.cc \ + utilities/env_mirror.cc \ utilities/flashcache/flashcache.cc \ utilities/geodb/geodb_impl.cc \ utilities/leveldb_options/leveldb_options.cc \ diff --git a/utilities/env_mirror.cc b/utilities/env_mirror.cc new file mode 100644 index 000000000..806711382 --- /dev/null +++ b/utilities/env_mirror.cc @@ -0,0 +1,266 @@ +// Copyright (c) 2015, Red Hat, Inc. All rights reserved. +// This source code is licensed under the BSD-style license found in the +// LICENSE file in the root directory of this source tree. An additional grant +// of patent rights can be found in the PATENTS file in the same directory. +// Copyright (c) 2011 The LevelDB Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. See the AUTHORS file for names of contributors. + +#ifndef ROCKSDB_LITE + +#include "rocksdb/utilities/env_mirror.h" + +namespace rocksdb { + +// An implementaiton of Env that mirrors all work over two backend +// Env's. This is useful for debugging purposes. +class SequentialFileMirror : public SequentialFile { + public: + unique_ptr a_, b_; + std::string fname; + SequentialFileMirror(std::string f) : fname(f) {} + + Status Read(size_t n, Slice* result, char* scratch) { + Slice aslice; + Status as = a_->Read(n, &aslice, scratch); + if (as == Status::OK()) { + char* bscratch = new char[n]; + Slice bslice; + size_t off = 0; + size_t left = aslice.size(); + while (left) { + Status bs = b_->Read(left, &bslice, bscratch); + assert(as == bs); + assert(memcmp(bscratch, scratch + off, bslice.size()) == 0); + off += bslice.size(); + left -= bslice.size(); + } + delete[] bscratch; + *result = aslice; + } else { + Status bs = b_->Read(n, result, scratch); + assert(as == bs); + } + return as; + } + + Status Skip(uint64_t n) { + Status as = a_->Skip(n); + Status bs = b_->Skip(n); + assert(as == bs); + return as; + } + Status InvalidateCache(size_t offset, size_t length) { + Status as = a_->InvalidateCache(offset, length); + Status bs = b_->InvalidateCache(offset, length); + assert(as == bs); + return as; + }; +}; + +class RandomAccessFileMirror : public RandomAccessFile { + public: + unique_ptr a_, b_; + std::string fname; + RandomAccessFileMirror(std::string f) : fname(f) {} + + Status Read(uint64_t offset, size_t n, Slice* result, char* scratch) const { + Status as = a_->Read(offset, n, result, scratch); + if (as == Status::OK()) { + char* bscratch = new char[n]; + Slice bslice; + size_t off = 0; + size_t left = result->size(); + while (left) { + Status bs = b_->Read(offset + off, left, &bslice, bscratch); + assert(as == bs); + assert(memcmp(bscratch, scratch + off, bslice.size()) == 0); + off += bslice.size(); + left -= bslice.size(); + } + delete[] bscratch; + } else { + Status bs = b_->Read(offset, n, result, scratch); + assert(as == bs); + } + return as; + } + + bool ShouldForwardRawRequest() const { + // NOTE: not verified + return a_->ShouldForwardRawRequest(); + } + + size_t GetUniqueId(char* id, size_t max_size) const { + // NOTE: not verified + return a_->GetUniqueId(id, max_size); + } +}; + +class WritableFileMirror : public WritableFile { + public: + unique_ptr a_, b_; + std::string fname; + WritableFileMirror(std::string f) : fname(f) {} + + Status Append(const Slice& data) override { + Status as = a_->Append(data); + Status bs = b_->Append(data); + assert(as == bs); + return as; + } + Status PositionedAppend(const Slice& data, uint64_t offset) override { + Status as = a_->PositionedAppend(data, offset); + Status bs = b_->PositionedAppend(data, offset); + assert(as == bs); + return as; + } + Status Truncate(uint64_t size) override { + Status as = a_->Truncate(size); + Status bs = b_->Truncate(size); + assert(as == bs); + return as; + } + Status Close() override { + Status as = a_->Close(); + Status bs = b_->Close(); + assert(as == bs); + return as; + } + Status Flush() override { + Status as = a_->Flush(); + Status bs = b_->Flush(); + assert(as == bs); + return as; + } + Status Sync() override { + Status as = a_->Sync(); + Status bs = b_->Sync(); + assert(as == bs); + return as; + } + Status Fsync() override { + Status as = a_->Fsync(); + Status bs = b_->Fsync(); + assert(as == bs); + return as; + } + bool IsSyncThreadSafe() const override { + bool as = a_->IsSyncThreadSafe(); + bool bs = b_->IsSyncThreadSafe(); + assert(as == bs); + return as; + } + void SetIOPriority(Env::IOPriority pri) override { + a_->SetIOPriority(pri); + b_->SetIOPriority(pri); + } + Env::IOPriority GetIOPriority() override { + // NOTE: we don't verify this one + return a_->GetIOPriority(); + } + uint64_t GetFileSize() override { + uint64_t as = a_->GetFileSize(); + uint64_t bs = b_->GetFileSize(); + assert(as == bs); + return as; + } + void GetPreallocationStatus(size_t* block_size, + size_t* last_allocated_block) override { + // NOTE: we don't verify this one + return a_->GetPreallocationStatus(block_size, last_allocated_block); + } + size_t GetUniqueId(char* id, size_t max_size) const override { + // NOTE: we don't verify this one + return a_->GetUniqueId(id, max_size); + } + Status InvalidateCache(size_t offset, size_t length) override { + Status as = a_->InvalidateCache(offset, length); + Status bs = b_->InvalidateCache(offset, length); + assert(as == bs); + return as; + } + + protected: + Status Allocate(uint64_t offset, uint64_t length) override { + Status as = a_->Allocate(offset, length); + Status bs = b_->Allocate(offset, length); + assert(as == bs); + return as; + } + Status RangeSync(uint64_t offset, uint64_t nbytes) override { + Status as = a_->RangeSync(offset, nbytes); + Status bs = b_->RangeSync(offset, nbytes); + assert(as == bs); + return as; + } +}; + +Status EnvMirror::NewSequentialFile(const std::string& f, + unique_ptr* r, + const EnvOptions& options) { + if (f.find("/proc/") == 0) { + return a_->NewSequentialFile(f, r, options); + } + SequentialFileMirror* mf = new SequentialFileMirror(f); + Status as = a_->NewSequentialFile(f, &mf->a_, options); + Status bs = b_->NewSequentialFile(f, &mf->b_, options); + assert(as == bs); + if (as.ok()) + r->reset(mf); + else + delete mf; + return as; +} + +Status EnvMirror::NewRandomAccessFile(const std::string& f, + unique_ptr* r, + const EnvOptions& options) { + if (f.find("/proc/") == 0) { + return a_->NewRandomAccessFile(f, r, options); + } + RandomAccessFileMirror* mf = new RandomAccessFileMirror(f); + Status as = a_->NewRandomAccessFile(f, &mf->a_, options); + Status bs = b_->NewRandomAccessFile(f, &mf->b_, options); + assert(as == bs); + if (as.ok()) + r->reset(mf); + else + delete mf; + return as; +} + +Status EnvMirror::NewWritableFile(const std::string& f, + unique_ptr* r, + const EnvOptions& options) { + if (f.find("/proc/") == 0) return a_->NewWritableFile(f, r, options); + WritableFileMirror* mf = new WritableFileMirror(f); + Status as = a_->NewWritableFile(f, &mf->a_, options); + Status bs = b_->NewWritableFile(f, &mf->b_, options); + assert(as == bs); + if (as.ok()) + r->reset(mf); + else + delete mf; + return as; +} + +Status EnvMirror::ReuseWritableFile(const std::string& fname, + const std::string& old_fname, + unique_ptr* r, + const EnvOptions& options) { + if (fname.find("/proc/") == 0) + return a_->ReuseWritableFile(fname, old_fname, r, options); + WritableFileMirror* mf = new WritableFileMirror(fname); + Status as = a_->ReuseWritableFile(fname, old_fname, &mf->a_, options); + Status bs = b_->ReuseWritableFile(fname, old_fname, &mf->b_, options); + assert(as == bs); + if (as.ok()) + r->reset(mf); + else + delete mf; + return as; +} + +} // namespace rocksdb +#endif diff --git a/utilities/env_mirror_test.cc b/utilities/env_mirror_test.cc new file mode 100644 index 000000000..845356bf6 --- /dev/null +++ b/utilities/env_mirror_test.cc @@ -0,0 +1,222 @@ +// Copyright (c) 2015, Red Hat, Inc. All rights reserved. +// This source code is licensed under the BSD-style license found in the +// LICENSE file in the root directory of this source tree. An additional grant +// of patent rights can be found in the PATENTS file in the same directory. + +#ifndef ROCKSDB_LITE + +#include "rocksdb/utilities/env_mirror.h" +#include "util/mock_env.h" +#include "util/testharness.h" + +namespace rocksdb { + +class EnvMirrorTest : public testing::Test { + public: + Env* default_; + MockEnv* a_, *b_; + EnvMirror* env_; + const EnvOptions soptions_; + + EnvMirrorTest() + : default_(Env::Default()), + a_(new MockEnv(default_)), + b_(new MockEnv(default_)), + env_(new EnvMirror(a_, b_)) {} + ~EnvMirrorTest() { + delete env_; + delete a_; + delete b_; + } +}; + +TEST_F(EnvMirrorTest, Basics) { + uint64_t file_size; + unique_ptr writable_file; + std::vector children; + + ASSERT_OK(env_->CreateDir("/dir")); + + // Check that the directory is empty. + ASSERT_EQ(Status::NotFound(), env_->FileExists("/dir/non_existent")); + ASSERT_TRUE(!env_->GetFileSize("/dir/non_existent", &file_size).ok()); + ASSERT_OK(env_->GetChildren("/dir", &children)); + ASSERT_EQ(0U, children.size()); + + // Create a file. + ASSERT_OK(env_->NewWritableFile("/dir/f", &writable_file, soptions_)); + writable_file.reset(); + + // Check that the file exists. + ASSERT_OK(env_->FileExists("/dir/f")); + ASSERT_OK(a_->FileExists("/dir/f")); + ASSERT_OK(b_->FileExists("/dir/f")); + ASSERT_OK(env_->GetFileSize("/dir/f", &file_size)); + ASSERT_EQ(0U, file_size); + ASSERT_OK(env_->GetChildren("/dir", &children)); + ASSERT_EQ(1U, children.size()); + ASSERT_EQ("f", children[0]); + ASSERT_OK(a_->GetChildren("/dir", &children)); + ASSERT_EQ(1U, children.size()); + ASSERT_EQ("f", children[0]); + ASSERT_OK(b_->GetChildren("/dir", &children)); + ASSERT_EQ(1U, children.size()); + ASSERT_EQ("f", children[0]); + + // Write to the file. + ASSERT_OK(env_->NewWritableFile("/dir/f", &writable_file, soptions_)); + ASSERT_OK(writable_file->Append("abc")); + writable_file.reset(); + + // Check for expected size. + ASSERT_OK(env_->GetFileSize("/dir/f", &file_size)); + ASSERT_EQ(3U, file_size); + ASSERT_OK(a_->GetFileSize("/dir/f", &file_size)); + ASSERT_EQ(3U, file_size); + ASSERT_OK(b_->GetFileSize("/dir/f", &file_size)); + ASSERT_EQ(3U, file_size); + + // Check that renaming works. + ASSERT_TRUE(!env_->RenameFile("/dir/non_existent", "/dir/g").ok()); + ASSERT_OK(env_->RenameFile("/dir/f", "/dir/g")); + ASSERT_EQ(Status::NotFound(), env_->FileExists("/dir/f")); + ASSERT_OK(env_->FileExists("/dir/g")); + ASSERT_OK(env_->GetFileSize("/dir/g", &file_size)); + ASSERT_EQ(3U, file_size); + ASSERT_OK(a_->FileExists("/dir/g")); + ASSERT_OK(a_->GetFileSize("/dir/g", &file_size)); + ASSERT_EQ(3U, file_size); + ASSERT_OK(b_->FileExists("/dir/g")); + ASSERT_OK(b_->GetFileSize("/dir/g", &file_size)); + ASSERT_EQ(3U, file_size); + + // Check that opening non-existent file fails. + unique_ptr seq_file; + unique_ptr rand_file; + ASSERT_TRUE( + !env_->NewSequentialFile("/dir/non_existent", &seq_file, soptions_).ok()); + ASSERT_TRUE(!seq_file); + ASSERT_TRUE(!env_->NewRandomAccessFile("/dir/non_existent", &rand_file, + soptions_).ok()); + ASSERT_TRUE(!rand_file); + + // Check that deleting works. + ASSERT_TRUE(!env_->DeleteFile("/dir/non_existent").ok()); + ASSERT_OK(env_->DeleteFile("/dir/g")); + ASSERT_EQ(Status::NotFound(), env_->FileExists("/dir/g")); + ASSERT_OK(env_->GetChildren("/dir", &children)); + ASSERT_EQ(0U, children.size()); + ASSERT_OK(env_->DeleteDir("/dir")); +} + +TEST_F(EnvMirrorTest, ReadWrite) { + unique_ptr writable_file; + unique_ptr seq_file; + unique_ptr rand_file; + Slice result; + char scratch[100]; + + ASSERT_OK(env_->CreateDir("/dir")); + + ASSERT_OK(env_->NewWritableFile("/dir/f", &writable_file, soptions_)); + ASSERT_OK(writable_file->Append("hello ")); + ASSERT_OK(writable_file->Append("world")); + writable_file.reset(); + + // Read sequentially. + ASSERT_OK(env_->NewSequentialFile("/dir/f", &seq_file, soptions_)); + ASSERT_OK(seq_file->Read(5, &result, scratch)); // Read "hello". + ASSERT_EQ(0, result.compare("hello")); + ASSERT_OK(seq_file->Skip(1)); + ASSERT_OK(seq_file->Read(1000, &result, scratch)); // Read "world". + ASSERT_EQ(0, result.compare("world")); + ASSERT_OK(seq_file->Read(1000, &result, scratch)); // Try reading past EOF. + ASSERT_EQ(0U, result.size()); + ASSERT_OK(seq_file->Skip(100)); // Try to skip past end of file. + ASSERT_OK(seq_file->Read(1000, &result, scratch)); + ASSERT_EQ(0U, result.size()); + + // Random reads. + ASSERT_OK(env_->NewRandomAccessFile("/dir/f", &rand_file, soptions_)); + ASSERT_OK(rand_file->Read(6, 5, &result, scratch)); // Read "world". + ASSERT_EQ(0, result.compare("world")); + ASSERT_OK(rand_file->Read(0, 5, &result, scratch)); // Read "hello". + ASSERT_EQ(0, result.compare("hello")); + ASSERT_OK(rand_file->Read(10, 100, &result, scratch)); // Read "d". + ASSERT_EQ(0, result.compare("d")); + + // Too high offset. + ASSERT_TRUE(!rand_file->Read(1000, 5, &result, scratch).ok()); +} + +TEST_F(EnvMirrorTest, Locks) { + FileLock* lock; + + // These are no-ops, but we test they return success. + ASSERT_OK(env_->LockFile("some file", &lock)); + ASSERT_OK(env_->UnlockFile(lock)); +} + +TEST_F(EnvMirrorTest, Misc) { + std::string test_dir; + ASSERT_OK(env_->GetTestDirectory(&test_dir)); + ASSERT_TRUE(!test_dir.empty()); + + unique_ptr writable_file; + ASSERT_OK(env_->NewWritableFile("/a/b", &writable_file, soptions_)); + + // These are no-ops, but we test they return success. + ASSERT_OK(writable_file->Sync()); + ASSERT_OK(writable_file->Flush()); + ASSERT_OK(writable_file->Close()); + writable_file.reset(); +} + +TEST_F(EnvMirrorTest, LargeWrite) { + const size_t kWriteSize = 300 * 1024; + char* scratch = new char[kWriteSize * 2]; + + std::string write_data; + for (size_t i = 0; i < kWriteSize; ++i) { + write_data.append(1, static_cast(i)); + } + + unique_ptr writable_file; + ASSERT_OK(env_->NewWritableFile("/dir/f", &writable_file, soptions_)); + ASSERT_OK(writable_file->Append("foo")); + ASSERT_OK(writable_file->Append(write_data)); + writable_file.reset(); + + unique_ptr seq_file; + Slice result; + ASSERT_OK(env_->NewSequentialFile("/dir/f", &seq_file, soptions_)); + ASSERT_OK(seq_file->Read(3, &result, scratch)); // Read "foo". + ASSERT_EQ(0, result.compare("foo")); + + size_t read = 0; + std::string read_data; + while (read < kWriteSize) { + ASSERT_OK(seq_file->Read(kWriteSize - read, &result, scratch)); + read_data.append(result.data(), result.size()); + read += result.size(); + } + ASSERT_TRUE(write_data == read_data); + delete[] scratch; +} + +} // namespace rocksdb + +int main(int argc, char** argv) { + ::testing::InitGoogleTest(&argc, argv); + return RUN_ALL_TESTS(); +} + +#else +#include + +int main(int argc, char** argv) { + fprintf(stderr, "SKIPPED as EnvMirror is not supported in ROCKSDB_LITE\n"); + return 0; +} + +#endif // !ROCKSDB_LITE