143   IOStatus NewSequentialFile(const std::string& fname,  in NewSequentialFile()
154       return IOStatus::IOError(fname,  in NewSequentialFile()
194     return IOStatus::OK();  in NewSequentialFile()
197   IOStatus NewRandomAccessFile(const std::string& fname,  in NewRandomAccessFile()
202     IOStatus s;  in NewRandomAccessFile()
208       return IOStatus::IOError(fname,  in NewRandomAccessFile()
264   virtual IOStatus OpenWritableFile(const std::string& fname,  in OpenWritableFile()
270     IOStatus s;  in OpenWritableFile()
283       return IOStatus::IOError(fname,  in OpenWritableFile()
356   IOStatus NewWritableFile(const std::string& fname, const FileOptions& options,  in NewWritableFile()
362   IOStatus ReopenWritableFile(const std::string& fname,  in ReopenWritableFile()
369   IOStatus ReuseWritableFile(const std::string& fname,  in ReuseWritableFile()
375     IOStatus s;  in ReuseWritableFile()
382       return IOStatus::IOError(fname,  in ReuseWritableFile()
462   IOStatus NewRandomRWFile(const std::string& fname, const FileOptions& options,  in NewRandomRWFile()
483     return IOStatus::OK();  in NewRandomRWFile()
486   IOStatus NewMemoryMappedFileBuffer(  in NewMemoryMappedFileBuffer()
490     IOStatus status;  in NewMemoryMappedFileBuffer()
530   IOStatus NewDirectory(const std::string& name, const IOOptions& /*opts*/,  in NewDirectory()
545     return IOStatus::OK();  in NewDirectory()
548   IOStatus NewLogger(const std::string& fname, const IOOptions& /*opts*/,  in NewLogger()
574       return IOStatus::OK();  in NewLogger()
578   IOStatus FileExists(const std::string& fname, const IOOptions& /*opts*/,  in FileExists()
583       return IOStatus::OK();  in FileExists()
593         return IOStatus::NotFound();  in FileExists()
596         return IOStatus::IOError("Unexpected error(" + ToString(err) +  in FileExists()
601   IOStatus GetChildren(const std::string& dir, const IOOptions& /*opts*/,  in GetChildren()
611           return IOStatus::NotFound();  in GetChildren()
621     return IOStatus::OK();  in GetChildren()
624   IOStatus DeleteFile(const std::string& fname, const IOOptions& /*opts*/,  in DeleteFile()
626     IOStatus result;  in DeleteFile()
633   IOStatus CreateDir(const std::string& name, const IOOptions& /*opts*/,  in CreateDir()
635     IOStatus result;  in CreateDir()
642   IOStatus CreateDirIfMissing(const std::string& name,  in CreateDirIfMissing()
645     IOStatus result;  in CreateDirIfMissing()
653             IOStatus::IOError("`" + name + "' exists but is not a directory");  in CreateDirIfMissing()
659   IOStatus DeleteDir(const std::string& name, const IOOptions& /*opts*/,  in DeleteDir()
661     IOStatus result;  in DeleteDir()
668   IOStatus GetFileSize(const std::string& fname, const IOOptions& /*opts*/,  in GetFileSize()
670     IOStatus s;  in GetFileSize()
681   IOStatus GetFileModificationTime(const std::string& fname,  in GetFileModificationTime()
690     return IOStatus::OK();  in GetFileModificationTime()
693   IOStatus RenameFile(const std::string& src, const std::string& target,  in RenameFile()
696     IOStatus result;  in RenameFile()
703   IOStatus LinkFile(const std::string& src, const std::string& target,  in LinkFile()
706     IOStatus result;  in LinkFile()
709         return IOStatus::NotSupported("No cross FS links allowed");  in LinkFile()
716   IOStatus NumFileLinks(const std::string& fname, const IOOptions& /*opts*/,  in NumFileLinks()
723     return IOStatus::OK();  in NumFileLinks()
726   IOStatus AreFilesSame(const std::string& first, const std::string& second,  in AreFilesSame()
744     return IOStatus::OK();  in AreFilesSame()
747   IOStatus LockFile(const std::string& fname, const IOOptions& /*opts*/,  in LockFile()
750     IOStatus result;  in LockFile()
810   IOStatus UnlockFile(FileLock* lock, const IOOptions& /*opts*/,  in UnlockFile()
813     IOStatus result;  in UnlockFile()
829   IOStatus GetAbsolutePath(const std::string& db_path,  in GetAbsolutePath()
834       return IOStatus::OK();  in GetAbsolutePath()
840       return IOStatus::IOError(strerror(errno));  in GetAbsolutePath()
844     return IOStatus::OK();  in GetAbsolutePath()
847   IOStatus GetTestDirectory(const IOOptions& /*opts*/, std::string* result,  in GetTestDirectory()
862     return IOStatus::OK();  in GetTestDirectory()
865   IOStatus GetFreeSpace(const std::string& fname, const IOOptions& /*opts*/,  in GetFreeSpace()
875     return IOStatus::OK();  in GetFreeSpace()