Correct class/structure declaration order.

1. Correct the class/struct declaration order to be IAW
   the Google C++ style guide[1].
2. For non-copyable classes, switched from non-implemented
   private methods to explicitly deleted[2] methods.
3. Minor const and member initialization fixes.

[1] https://google.github.io/styleguide/cppguide.html#Declaration_Order
[2] http://eel.is/c++draft/dcl.fct.def.delete

PiperOrigin-RevId: 246521844

19 files changed, 285 insertions, 278 deletions

diff --git a/db/autocompact_test.cc b/db/autocompact_test.cc
index 00e3672..e6c97a0 100644
--- a/db/autocompact_test.cc
+++ b/db/autocompact_test.cc
@@ -12,11 +12,6 @@ namespace leveldb {
 
 class AutoCompactTest {
  public:
-  std::string dbname_;
-  Cache* tiny_cache_;
-  Options options_;
-  DB* db_;
-
   AutoCompactTest() {
     dbname_ = test::TmpDir() + "/autocompact_test";
     tiny_cache_ = NewLRUCache(100);
@@ -47,6 +42,12 @@ class AutoCompactTest {
   }
 
   void DoReads(int n);
+
+ private:
+  std::string dbname_;
+  Cache* tiny_cache_;
+  Options options_;
+  DB* db_;
 };
 
 static const int kValueSize = 200 * 1024;
diff --git a/db/c.cc b/db/c.cc
index 72f6daa..e0f3367 100644
--- a/db/c.cc
+++ b/db/c.cc
@@ -84,12 +84,6 @@ struct leveldb_filelock_t {
 };
 
 struct leveldb_comparator_t : public Comparator {
-  void* state_;
-  void (*destructor_)(void*);
-  int (*compare_)(void*, const char* a, size_t alen, const char* b,
-                  size_t blen);
-  const char* (*name_)(void*);
-
   virtual ~leveldb_comparator_t() { (*destructor_)(state_); }
 
   virtual int Compare(const Slice& a, const Slice& b) const {
@@ -101,18 +95,15 @@ struct leveldb_comparator_t : public Comparator {
   // No-ops since the C binding does not support key shortening methods.
   virtual void FindShortestSeparator(std::string*, const Slice&) const {}
   virtual void FindShortSuccessor(std::string* key) const {}
-};
 
-struct leveldb_filterpolicy_t : public FilterPolicy {
   void* state_;
   void (*destructor_)(void*);
+  int (*compare_)(void*, const char* a, size_t alen, const char* b,
+                  size_t blen);
   const char* (*name_)(void*);
-  char* (*create_)(void*, const char* const* key_array,
-                   const size_t* key_length_array, int num_keys,
-                   size_t* filter_length);
-  unsigned char (*key_match_)(void*, const char* key, size_t length,
-                              const char* filter, size_t filter_length);
+};
 
+struct leveldb_filterpolicy_t : public FilterPolicy {
   virtual ~leveldb_filterpolicy_t() { (*destructor_)(state_); }
 
   virtual const char* Name() const { return (*name_)(state_); }
@@ -134,6 +125,15 @@ struct leveldb_filterpolicy_t : public FilterPolicy {
     return (*key_match_)(state_, key.data(), key.size(), filter.data(),
                          filter.size());
   }
+
+  void* state_;
+  void (*destructor_)(void*);
+  const char* (*name_)(void*);
+  char* (*create_)(void*, const char* const* key_array,
+                   const size_t* key_length_array, int num_keys,
+                   size_t* filter_length);
+  unsigned char (*key_match_)(void*, const char* key, size_t length,
+                              const char* filter, size_t filter_length);
 };
 
 struct leveldb_env_t {
@@ -470,7 +470,8 @@ leveldb_filterpolicy_t* leveldb_filterpolicy_create_bloom(int bits_per_key) {
   // they delegate to a NewBloomFilterPolicy() instead of user
   // supplied C functions.
   struct Wrapper : public leveldb_filterpolicy_t {
-    const FilterPolicy* rep_;
+    static void DoNothing(void*) {}
+
     ~Wrapper() { delete rep_; }
     const char* Name() const { return rep_->Name(); }
     void CreateFilter(const Slice* keys, int n, std::string* dst) const {
@@ -479,7 +480,8 @@ leveldb_filterpolicy_t* leveldb_filterpolicy_create_bloom(int bits_per_key) {
     bool KeyMayMatch(const Slice& key, const Slice& filter) const {
       return rep_->KeyMayMatch(key, filter);
     }
-    static void DoNothing(void*) {}
+
+    const FilterPolicy* rep_;
   };
   Wrapper* wrapper = new Wrapper;
   wrapper->rep_ = NewBloomFilterPolicy(bits_per_key);
diff --git a/db/corruption_test.cc b/db/corruption_test.cc
index e6f64ee..42f5237 100644
--- a/db/corruption_test.cc
+++ b/db/corruption_test.cc
@@ -22,20 +22,14 @@ static const int kValueSize = 1000;
 
 class CorruptionTest {
  public:
-  test::ErrorEnv env_;
-  std::string dbname_;
-  Cache* tiny_cache_;
-  Options options_;
-  DB* db_;
-
-  CorruptionTest() {
-    tiny_cache_ = NewLRUCache(100);
+  CorruptionTest()
+      : db_(nullptr),
+        dbname_("/memenv/corruption_test"),
+        tiny_cache_(NewLRUCache(100)) {
     options_.env = &env_;
     options_.block_cache = tiny_cache_;
-    dbname_ = "/memenv/corruption_test";
     DestroyDB(dbname_, options_);
 
-    db_ = nullptr;
     options_.create_if_missing = true;
     Reopen();
     options_.create_if_missing = false;
@@ -185,6 +179,14 @@ class CorruptionTest {
     Random r(k);
     return test::RandomString(&r, kValueSize, storage);
   }
+
+  test::ErrorEnv env_;
+  Options options_;
+  DB* db_;
+
+ private:
+  std::string dbname_;
+  Cache* tiny_cache_;
 };
 
 TEST(CorruptionTest, Recovery) {
diff --git a/db/db_impl.cc b/db/db_impl.cc
index bff2d62..761ebf6 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -42,38 +42,23 @@ const int kNumNonTableCacheFiles = 10;
 
 // Information kept for every waiting writer
 struct DBImpl::Writer {
+  explicit Writer(port::Mutex* mu)
+      : batch(nullptr), sync(false), done(false), cv(mu) {}
+
   Status status;
   WriteBatch* batch;
   bool sync;
   bool done;
   port::CondVar cv;
-
-  explicit Writer(port::Mutex* mu)
-      : batch(nullptr), sync(false), done(false), cv(mu) {}
 };
 
 struct DBImpl::CompactionState {
-  Compaction* const compaction;
-
-  // Sequence numbers < smallest_snapshot are not significant since we
-  // will never have to service a snapshot below smallest_snapshot.
-  // Therefore if we have seen a sequence number S <= smallest_snapshot,
-  // we can drop all entries for the same key with sequence numbers < S.
-  SequenceNumber smallest_snapshot;
-
   // Files produced by compaction
   struct Output {
     uint64_t number;
     uint64_t file_size;
     InternalKey smallest, largest;
   };
-  std::vector<Output> outputs;
-
-  // State kept for output being generated
-  WritableFile* outfile;
-  TableBuilder* builder;
-
-  uint64_t total_bytes;
 
   Output* current_output() { return &outputs[outputs.size() - 1]; }
 
@@ -83,6 +68,22 @@ struct DBImpl::CompactionState {
         outfile(nullptr),
         builder(nullptr),
         total_bytes(0) {}
+
+  Compaction* const compaction;
+
+  // Sequence numbers < smallest_snapshot are not significant since we
+  // will never have to service a snapshot below smallest_snapshot.
+  // Therefore if we have seen a sequence number S <= smallest_snapshot,
+  // we can drop all entries for the same key with sequence numbers < S.
+  SequenceNumber smallest_snapshot;
+
+  std::vector<Output> outputs;
+
+  // State kept for output being generated
+  WritableFile* outfile;
+  TableBuilder* builder;
+
+  uint64_t total_bytes;
 };
 
 // Fix user-supplied options to be reasonable
diff --git a/db/db_impl.h b/db/db_impl.h
index c895952..ae87d6e 100644
--- a/db/db_impl.h
+++ b/db/db_impl.h
@@ -29,6 +29,10 @@ class VersionSet;
 class DBImpl : public DB {
  public:
   DBImpl(const Options& options, const std::string& dbname);
+
+  DBImpl(const DBImpl&) = delete;
+  DBImpl& operator=(const DBImpl&) = delete;
+
   virtual ~DBImpl();
 
   // Implementations of the DB interface
@@ -71,6 +75,31 @@ class DBImpl : public DB {
   struct CompactionState;
   struct Writer;
 
+  // Information for a manual compaction
+  struct ManualCompaction {
+    int level;
+    bool done;
+    const InternalKey* begin;  // null means beginning of key range
+    const InternalKey* end;    // null means end of key range
+    InternalKey tmp_storage;   // Used to keep track of compaction progress
+  };
+
+  // Per level compaction stats.  stats_[level] stores the stats for
+  // compactions that produced data for the specified "level".
+  struct CompactionStats {
+    CompactionStats() : micros(0), bytes_read(0), bytes_written(0) {}
+
+    void Add(const CompactionStats& c) {
+      this->micros += c.micros;
+      this->bytes_read += c.bytes_read;
+      this->bytes_written += c.bytes_written;
+    }
+
+    int64_t micros;
+    int64_t bytes_read;
+    int64_t bytes_written;
+  };
+
   Iterator* NewInternalIterator(const ReadOptions&,
                                 SequenceNumber* latest_snapshot,
                                 uint32_t* seed);
@@ -121,6 +150,10 @@ class DBImpl : public DB {
   Status InstallCompactionResults(CompactionState* compact)
       EXCLUSIVE_LOCKS_REQUIRED(mutex_);
 
+  const Comparator* user_comparator() const {
+    return internal_comparator_.user_comparator();
+  }
+
   // Constant after construction
   Env* const env_;
   const InternalKeyComparator internal_comparator_;
@@ -161,14 +194,6 @@ class DBImpl : public DB {
   // Has a background compaction been scheduled or is running?
   bool background_compaction_scheduled_ GUARDED_BY(mutex_);
 
-  // Information for a manual compaction
-  struct ManualCompaction {
-    int level;
-    bool done;
-    const InternalKey* begin;  // null means beginning of key range
-    const InternalKey* end;    // null means end of key range
-    InternalKey tmp_storage;   // Used to keep track of compaction progress
-  };
   ManualCompaction* manual_compaction_ GUARDED_BY(mutex_);
 
   VersionSet* const versions_;
@@ -176,30 +201,7 @@ class DBImpl : public DB {
   // Have we encountered a background error in paranoid mode?
   Status bg_error_ GUARDED_BY(mutex_);
 
-  // Per level compaction stats.  stats_[level] stores the stats for
-  // compactions that produced data for the specified "level".
-  struct CompactionStats {
-    int64_t micros;
-    int64_t bytes_read;
-    int64_t bytes_written;
-
-    CompactionStats() : micros(0), bytes_read(0), bytes_written(0) {}
-
-    void Add(const CompactionStats& c) {
-      this->micros += c.micros;
-      this->bytes_read += c.bytes_read;
-      this->bytes_written += c.bytes_written;
-    }
-  };
   CompactionStats stats_[config::kNumLevels] GUARDED_BY(mutex_);
-
-  // No copying allowed
-  DBImpl(const DBImpl&);
-  void operator=(const DBImpl&);
-
-  const Comparator* user_comparator() const {
-    return internal_comparator_.user_comparator();
-  }
 };
 
 // Sanitize db options.  The caller should delete result.info_log if
diff --git a/db/db_iter.cc b/db/db_iter.cc
index 1e5b5e2..8ff288e 100644
--- a/db/db_iter.cc
+++ b/db/db_iter.cc
@@ -55,6 +55,10 @@ class DBIter : public Iterator {
         valid_(false),
         rnd_(seed),
         bytes_until_read_sampling_(RandomCompactionPeriod()) {}
+
+  DBIter(const DBIter&) = delete;
+  DBIter& operator=(const DBIter&) = delete;
+
   virtual ~DBIter() { delete iter_; }
   virtual bool Valid() const { return valid_; }
   virtual Slice key() const {
@@ -106,19 +110,13 @@ class DBIter : public Iterator {
   const Comparator* const user_comparator_;
   Iterator* const iter_;
   SequenceNumber const sequence_;
-
   Status status_;
   std::string saved_key_;    // == current key when direction_==kReverse
   std::string saved_value_;  // == current raw value when direction_==kReverse
   Direction direction_;
   bool valid_;
-
   Random rnd_;
   size_t bytes_until_read_sampling_;
-
-  // No copying allowed
-  DBIter(const DBIter&);
-  void operator=(const DBIter&);
 };
 
 inline bool DBIter::ParseKey(ParsedInternalKey* ikey) {
diff --git a/db/db_test.cc b/db/db_test.cc
index 4343216..78296d5 100644
--- a/db/db_test.cc
+++ b/db/db_test.cc
@@ -40,10 +40,6 @@ static std::string RandomKey(Random* rnd) {
 
 namespace {
 class AtomicCounter {
- private:
-  port::Mutex mu_;
-  int count_ GUARDED_BY(mu_);
-
  public:
   AtomicCounter() : count_(0) {}
   void Increment() { IncrementBy(1); }
@@ -59,6 +55,10 @@ class AtomicCounter {
     MutexLock l(&mu_);
     count_ = 0;
   }
+
+ private:
+  port::Mutex mu_;
+  int count_ GUARDED_BY(mu_);
 };
 
 void DelayMilliseconds(int millis) {
@@ -227,13 +227,6 @@ class SpecialEnv : public EnvWrapper {
 };
 
 class DBTest {
- private:
-  const FilterPolicy* filter_policy_;
-
-  // Sequence of option configurations to try
-  enum OptionConfig { kDefault, kReuse, kFilter, kUncompressed, kEnd };
-  int option_config_;
-
  public:
   std::string dbname_;
   SpecialEnv* env_;
@@ -241,7 +234,7 @@ class DBTest {
 
   Options last_options_;
 
-  DBTest() : option_config_(kDefault), env_(new SpecialEnv(Env::Default())) {
+  DBTest() : env_(new SpecialEnv(Env::Default())), option_config_(kDefault) {
     filter_policy_ = NewBloomFilterPolicy(10);
     dbname_ = test::TmpDir() + "/db_test";
     DestroyDB(dbname_, Options());
@@ -533,6 +526,13 @@ class DBTest {
     }
     return files_renamed;
   }
+
+ private:
+  // Sequence of option configurations to try
+  enum OptionConfig { kDefault, kReuse, kFilter, kUncompressed, kEnd };
+
+  const FilterPolicy* filter_policy_;
+  int option_config_;
 };
 
 TEST(DBTest, Empty) {
diff --git a/db/dbformat.h b/db/dbformat.h
index bdc23b8..013028a 100644
--- a/db/dbformat.h
+++ b/db/dbformat.h
@@ -181,6 +181,9 @@ class LookupKey {
   // the specified sequence number.
   LookupKey(const Slice& user_key, SequenceNumber sequence);
 
+  LookupKey(const LookupKey&) = delete;
+  LookupKey& operator=(const LookupKey&) = delete;
+
   ~LookupKey();
 
   // Return a key suitable for lookup in a MemTable.
@@ -204,10 +207,6 @@ class LookupKey {
   const char* kstart_;
   const char* end_;
   char space_[200];  // Avoid allocation for short keys
-
-  // No copying allowed
-  LookupKey(const LookupKey&);
-  void operator=(const LookupKey&);
 };
 
 inline LookupKey::~LookupKey() {
diff --git a/db/dumpfile.cc b/db/dumpfile.cc
index 1dbff5e..9d22d58 100644
--- a/db/dumpfile.cc
+++ b/db/dumpfile.cc
@@ -38,7 +38,6 @@ bool GuessType(const std::string& fname, FileType* type) {
 // Notified when log reader encounters corruption.
 class CorruptionReporter : public log::Reader::Reporter {
  public:
-  WritableFile* dst_;
   virtual void Corruption(size_t bytes, const Status& status) {
     std::string r = "corruption: ";
     AppendNumberTo(&r, bytes);
@@ -47,6 +46,8 @@ class CorruptionReporter : public log::Reader::Reporter {
     r.push_back('\n');
     dst_->Append(r);
   }
+
+  WritableFile* dst_;
 };
 
 // Print contents of a log file. (*func)() is called on every record.
@@ -73,7 +74,6 @@ Status PrintLogContents(Env* env, const std::string& fname,
 // Called on every item found in a WriteBatch.
 class WriteBatchItemPrinter : public WriteBatch::Handler {
  public:
-  WritableFile* dst_;
   virtual void Put(const Slice& key, const Slice& value) {
     std::string r = "  put '";
     AppendEscapedStringTo(&r, key);
@@ -88,6 +88,8 @@ class WriteBatchItemPrinter : public WriteBatch::Handler {
     r += "'\n";
     dst_->Append(r);
   }
+
+  WritableFile* dst_;
 };
 
 // Called on every log record (each one of which is a WriteBatch)
diff --git a/db/log_reader.h b/db/log_reader.h
index b27c164..001da89 100644
--- a/db/log_reader.h
+++ b/db/log_reader.h
@@ -43,6 +43,9 @@ class Reader {
   Reader(SequentialFile* file, Reporter* reporter, bool checksum,
          uint64_t initial_offset);
 
+  Reader(const Reader&) = delete;
+  Reader& operator=(const Reader&) = delete;
+
   ~Reader();
 
   // Read the next record into *record.  Returns true if read
@@ -58,26 +61,6 @@ class Reader {
   uint64_t LastRecordOffset();
 
  private:
-  SequentialFile* const file_;
-  Reporter* const reporter_;
-  bool const checksum_;
-  char* const backing_store_;
-  Slice buffer_;
-  bool eof_;  // Last Read() indicated EOF by returning < kBlockSize
-
-  // Offset of the last record returned by ReadRecord.
-  uint64_t last_record_offset_;
-  // Offset of the first location past the end of buffer_.
-  uint64_t end_of_buffer_offset_;
-
-  // Offset at which to start looking for the first record to return
-  uint64_t const initial_offset_;
-
-  // True if we are resynchronizing after a seek (initial_offset_ > 0). In
-  // particular, a run of kMiddleType and kLastType records can be silently
-  // skipped in this mode
-  bool resyncing_;
-
   // Extend record types with the following special values
   enum {
     kEof = kMaxRecordType + 1,
@@ -102,9 +85,25 @@ class Reader {
   void ReportCorruption(uint64_t bytes, const char* reason);
   void ReportDrop(uint64_t bytes, const Status& reason);
 
-  // No copying allowed
-  Reader(const Reader&);
-  void operator=(const Reader&);
+  SequentialFile* const file_;
+  Reporter* const reporter_;
+  bool const checksum_;
+  char* const backing_store_;
+  Slice buffer_;
+  bool eof_;  // Last Read() indicated EOF by returning < kBlockSize
+
+  // Offset of the last record returned by ReadRecord.
+  uint64_t last_record_offset_;
+  // Offset of the first location past the end of buffer_.
+  uint64_t end_of_buffer_offset_;
+
+  // Offset at which to start looking for the first record to return
+  uint64_t const initial_offset_;
+
+  // True if we are resynchronizing after a seek (initial_offset_ > 0). In
+  // particular, a run of kMiddleType and kLastType records can be silently
+  // skipped in this mode
+  bool resyncing_;
 };
 
 }  // namespace log
diff --git a/db/log_test.cc b/db/log_test.cc
index 3acaa33..809c418 100644
--- a/db/log_test.cc
+++ b/db/log_test.cc
@@ -37,81 +37,6 @@ static std::string RandomSkewedString(int i, Random* rnd) {
 }
 
 class LogTest {
- private:
-  class StringDest : public WritableFile {
-   public:
-    std::string contents_;
-
-    virtual Status Close() { return Status::OK(); }
-    virtual Status Flush() { return Status::OK(); }
-    virtual Status Sync() { return Status::OK(); }
-    virtual Status Append(const Slice& slice) {
-      contents_.append(slice.data(), slice.size());
-      return Status::OK();
-    }
-  };
-
-  class StringSource : public SequentialFile {
-   public:
-    Slice contents_;
-    bool force_error_;
-    bool returned_partial_;
-    StringSource() : force_error_(false), returned_partial_(false) {}
-
-    virtual Status Read(size_t n, Slice* result, char* scratch) {
-      ASSERT_TRUE(!returned_partial_) << "must not Read() after eof/error";
-
-      if (force_error_) {
-        force_error_ = false;
-        returned_partial_ = true;
-        return Status::Corruption("read error");
-      }
-
-      if (contents_.size() < n) {
-        n = contents_.size();
-        returned_partial_ = true;
-      }
-      *result = Slice(contents_.data(), n);
-      contents_.remove_prefix(n);
-      return Status::OK();
-    }
-
-    virtual Status Skip(uint64_t n) {
-      if (n > contents_.size()) {
-        contents_.clear();
-        return Status::NotFound("in-memory file skipped past end");
-      }
-
-      contents_.remove_prefix(n);
-
-      return Status::OK();
-    }
-  };
-
-  class ReportCollector : public Reader::Reporter {
-   public:
-    size_t dropped_bytes_;
-    std::string message_;
-
-    ReportCollector() : dropped_bytes_(0) {}
-    virtual void Corruption(size_t bytes, const Status& status) {
-      dropped_bytes_ += bytes;
-      message_.append(status.ToString());
-    }
-  };
-
-  StringDest dest_;
-  StringSource source_;
-  ReportCollector report_;
-  bool reading_;
-  Writer* writer_;
-  Reader* reader_;
-
-  // Record metadata for testing initial offset functionality
-  static size_t initial_offset_record_sizes_[];
-  static uint64_t initial_offset_last_record_offsets_[];
-  static int num_initial_offset_records_;
-
  public:
   LogTest()
       : reading_(false),
@@ -232,6 +157,82 @@ class LogTest {
     }
     delete offset_reader;
   }
+
+ private:
+  class StringDest : public WritableFile {
+   public:
+    virtual Status Close() { return Status::OK(); }
+    virtual Status Flush() { return Status::OK(); }
+    virtual Status Sync() { return Status::OK(); }
+    virtual Status Append(const Slice& slice) {
+      contents_.append(slice.data(), slice.size());
+      return Status::OK();
+    }
+
+    std::string contents_;
+  };
+
+  class StringSource : public SequentialFile {
+   public:
+    StringSource() : force_error_(false), returned_partial_(false) {}
+
+    virtual Status Read(size_t n, Slice* result, char* scratch) {
+      ASSERT_TRUE(!returned_partial_) << "must not Read() after eof/error";
+
+      if (force_error_) {
+        force_error_ = false;
+        returned_partial_ = true;
+        return Status::Corruption("read error");
+      }
+
+      if (contents_.size() < n) {
+        n = contents_.size();
+        returned_partial_ = true;
+      }
+      *result = Slice(contents_.data(), n);
+      contents_.remove_prefix(n);
+      return Status::OK();
+    }
+
+    virtual Status Skip(uint64_t n) {
+      if (n > contents_.size()) {
+        contents_.clear();
+        return Status::NotFound("in-memory file skipped past end");
+      }
+
+      contents_.remove_prefix(n);
+
+      return Status::OK();
+    }
+
+    Slice contents_;
+    bool force_error_;
+    bool returned_partial_;
+  };
+
+  class ReportCollector : public Reader::Reporter {
+   public:
+    ReportCollector() : dropped_bytes_(0) {}
+    virtual void Corruption(size_t bytes, const Status& status) {
+      dropped_bytes_ += bytes;
+      message_.append(status.ToString());
+    }
+
+    size_t dropped_bytes_;
+    std::string message_;
+  };
+
+  // Record metadata for testing initial offset functionality
+  static size_t initial_offset_record_sizes_[];
+  static uint64_t initial_offset_last_record_offsets_[];
+  static int num_initial_offset_records_;
+
+  StringDest dest_;
+  StringSource source_;
+  ReportCollector report_;
+  bool reading_;
+  Writer* writer_;
+  Reader* reader_;
 };
 
 size_t LogTest::initial_offset_record_sizes_[] = {
diff --git a/db/log_writer.h b/db/log_writer.h
index 840809d..c0a2114 100644
--- a/db/log_writer.h
+++ b/db/log_writer.h
@@ -29,11 +29,16 @@ class Writer {
   // "*dest" must remain live while this Writer is in use.
   Writer(WritableFile* dest, uint64_t dest_length);
 
+  Writer(const Writer&) = delete;
+  Writer& operator=(const Writer&) = delete;
+
   ~Writer();
 
   Status AddRecord(const Slice& slice);
 
  private:
+  Status EmitPhysicalRecord(RecordType type, const char* ptr, size_t length);
+
   WritableFile* dest_;
   int block_offset_;  // Current offset in block
 
@@ -41,12 +46,6 @@ class Writer {
   // pre-computed to reduce the overhead of computing the crc of the
   // record type stored in the header.
   uint32_t type_crc_[kMaxRecordType + 1];
-
-  Status EmitPhysicalRecord(RecordType type, const char* ptr, size_t length);
-
-  // No copying allowed
-  Writer(const Writer&);
-  void operator=(const Writer&);
 };
 
 }  // namespace log
diff --git a/db/memtable.h b/db/memtable.h
index ef18bb5..9d986b1 100644
--- a/db/memtable.h
+++ b/db/memtable.h
@@ -23,6 +23,9 @@ class MemTable {
   // is zero and the caller must call Ref() at least once.
   explicit MemTable(const InternalKeyComparator& comparator);
 
+  MemTable(const MemTable&) = delete;
+  MemTable& operator=(const MemTable&) = delete;
+
   // Increase reference count.
   void Ref() { ++refs_; }
 
@@ -60,26 +63,23 @@ class MemTable {
   bool Get(const LookupKey& key, std::string* value, Status* s);
 
  private:
-  ~MemTable();  // Private since only Unref() should be used to delete it
+  friend class MemTableIterator;
+  friend class MemTableBackwardIterator;
 
   struct KeyComparator {
     const InternalKeyComparator comparator;
     explicit KeyComparator(const InternalKeyComparator& c) : comparator(c) {}
     int operator()(const char* a, const char* b) const;
   };
-  friend class MemTableIterator;
-  friend class MemTableBackwardIterator;
 
   typedef SkipList<const char*, KeyComparator> Table;
 
+  ~MemTable();  // Private since only Unref() should be used to delete it
+
   KeyComparator comparator_;
   int refs_;
   Arena arena_;
   Table table_;
-
-  // No copying allowed
-  MemTable(const MemTable&);
-  void operator=(const MemTable&);
 };
 
 }  // namespace leveldb
diff --git a/db/repair.cc b/db/repair.cc
index d5ecc45..3c676ca 100644
--- a/db/repair.cc
+++ b/db/repair.cc
@@ -95,22 +95,6 @@ class Repairer {
     SequenceNumber max_sequence;
   };
 
-  std::string const dbname_;
-  Env* const env_;
-  InternalKeyComparator const icmp_;
-  InternalFilterPolicy const ipolicy_;
-  Options const options_;
-  bool owns_info_log_;
-  bool owns_cache_;
-  TableCache* table_cache_;
-  VersionEdit edit_;
-
-  std::vector<std::string> manifests_;
-  std::vector<uint64_t> table_numbers_;
-  std::vector<uint64_t> logs_;
-  std::vector<TableInfo> tables_;
-  uint64_t next_file_number_;
-
   Status FindFiles() {
     std::vector<std::string> filenames;
     Status status = env_->GetChildren(dbname_, &filenames);
@@ -439,6 +423,22 @@ class Repairer {
     Log(options_.info_log, "Archiving %s: %s\n", fname.c_str(),
         s.ToString().c_str());
   }
+
+  const std::string dbname_;
+  Env* const env_;
+  InternalKeyComparator const icmp_;
+  InternalFilterPolicy const ipolicy_;
+  const Options options_;
+  bool owns_info_log_;
+  bool owns_cache_;
+  TableCache* table_cache_;
+  VersionEdit edit_;
+
+  std::vector<std::string> manifests_;
+  std::vector<uint64_t> table_numbers_;
+  std::vector<uint64_t> logs_;
+  std::vector<TableInfo> tables_;
+  uint64_t next_file_number_;
 };
 }  // namespace
 
diff --git a/db/skiplist.h b/db/skiplist.h
index 05e5733..a59b45b 100644
--- a/db/skiplist.h
+++ b/db/skiplist.h
@@ -49,6 +49,9 @@ class SkipList {
   // must remain allocated for the lifetime of the skiplist object.
   explicit SkipList(Comparator cmp, Arena* arena);
 
+  SkipList(const SkipList&) = delete;
+  SkipList& operator=(const SkipList&) = delete;
+
   // Insert key into the list.
   // REQUIRES: nothing that compares equal to key is currently in the list.
   void Insert(const Key& key);
@@ -98,23 +101,10 @@ class SkipList {
  private:
   enum { kMaxHeight = 12 };
 
-  // Immutable after construction
-  Comparator const compare_;
-  Arena* const arena_;  // Arena used for allocations of nodes
-
-  Node* const head_;
-
-  // Modified only by Insert().  Read racily by readers, but stale
-  // values are ok.
-  std::atomic<int> max_height_;  // Height of the entire list
-
   inline int GetMaxHeight() const {
     return max_height_.load(std::memory_order_relaxed);
   }
 
-  // Read/written only by Insert().
-  Random rnd_;
-
   Node* NewNode(const Key& key, int height);
   int RandomHeight();
   bool Equal(const Key& a, const Key& b) const { return (compare_(a, b) == 0); }
@@ -137,9 +127,18 @@ class SkipList {
   // Return head_ if list is empty.
   Node* FindLast() const;
 
-  // No copying allowed
-  SkipList(const SkipList&);
-  void operator=(const SkipList&);
+  // Immutable after construction
+  Comparator const compare_;
+  Arena* const arena_;  // Arena used for allocations of nodes
+
+  Node* const head_;
+
+  // Modified only by Insert().  Read racily by readers, but stale
+  // values are ok.
+  std::atomic<int> max_height_;  // Height of the entire list
+
+  // Read/written only by Insert().
+  Random rnd_;
 };
 
 // Implementation details follow
diff --git a/db/table_cache.h b/db/table_cache.h
index 21ae92d..93069c8 100644
--- a/db/table_cache.h
+++ b/db/table_cache.h
@@ -45,12 +45,12 @@ class TableCache {
   void Evict(uint64_t file_number);
 
  private:
+  Status FindTable(uint64_t file_number, uint64_t file_size, Cache::Handle**);
+
   Env* const env_;
   const std::string dbname_;
   const Options& options_;
   Cache* cache_;
-
-  Status FindTable(uint64_t file_number, uint64_t file_size, Cache::Handle**);
 };
 
 }  // namespace leveldb
diff --git a/db/version_edit.h b/db/version_edit.h
index 3daf4ef..2dadda7 100644
--- a/db/version_edit.h
+++ b/db/version_edit.h
@@ -16,14 +16,14 @@ namespace leveldb {
 class VersionSet;
 
 struct FileMetaData {
+  FileMetaData() : refs(0), allowed_seeks(1 << 30), file_size(0) {}
+
   int refs;
   int allowed_seeks;  // Seeks allowed until compaction
   uint64_t number;
   uint64_t file_size;    // File size in bytes
   InternalKey smallest;  // Smallest internal key served by table
   InternalKey largest;   // Largest internal key served by table
-
-  FileMetaData() : refs(0), allowed_seeks(1 << 30), file_size(0) {}
 };
 
 class VersionEdit {
diff --git a/db/version_set.h b/db/version_set.h
index 334ebd9..69f3d70 100644
--- a/db/version_set.h
+++ b/db/version_set.h
@@ -59,11 +59,6 @@ bool SomeFileOverlapsRange(const InternalKeyComparator& icmp,
 
 class Version {
  public:
-  // Append to *iters a sequence of iterators that will
-  // yield the contents of this Version when merged together.
-  // REQUIRES: This version has been saved (see VersionSet::SaveTo)
-  void AddIterators(const ReadOptions&, std::vector<Iterator*>* iters);
-
   // Lookup the value for key.  If found, store it in *val and
   // return OK.  Else return a non-OK status.  Fills *stats.
   // REQUIRES: lock is not held
@@ -71,6 +66,12 @@ class Version {
     FileMetaData* seek_file;
     int seek_file_level;
   };
+
+  // Append to *iters a sequence of iterators that will
+  // yield the contents of this Version when merged together.
+  // REQUIRES: This version has been saved (see VersionSet::SaveTo)
+  void AddIterators(const ReadOptions&, std::vector<Iterator*>* iters);
+
   Status Get(const ReadOptions&, const LookupKey& key, std::string* val,
              GetStats* stats);
 
@@ -118,6 +119,22 @@ class Version {
   friend class VersionSet;
 
   class LevelFileNumIterator;
+
+  explicit Version(VersionSet* vset)
+      : vset_(vset),
+        next_(this),
+        prev_(this),
+        refs_(0),
+        file_to_compact_(nullptr),
+        file_to_compact_level_(-1),
+        compaction_score_(-1),
+        compaction_level_(-1) {}
+
+  Version(const Version&) = delete;
+  Version& operator=(const Version&) = delete;
+
+  ~Version();
+
   Iterator* NewConcatenatingIterator(const ReadOptions&, int level) const;
 
   // Call func(arg, level, f) for every file that overlaps user_key in
@@ -145,28 +162,15 @@ class Version {
   // are initialized by Finalize().
   double compaction_score_;
   int compaction_level_;
-
-  explicit Version(VersionSet* vset)
-      : vset_(vset),
-        next_(this),
-        prev_(this),
-        refs_(0),
-        file_to_compact_(nullptr),
-        file_to_compact_level_(-1),
-        compaction_score_(-1),
-        compaction_level_(-1) {}
-
-  ~Version();
-
-  // No copying allowed
-  Version(const Version&);
-  void operator=(const Version&);
 };
 
 class VersionSet {
  public:
   VersionSet(const std::string& dbname, const Options* options,
              TableCache* table_cache, const InternalKeyComparator*);
+  VersionSet(const VersionSet&) = delete;
+  VersionSet& operator=(const VersionSet&) = delete;
+
   ~VersionSet();
 
   // Apply *edit to the current version to form a new descriptor that
@@ -309,10 +313,6 @@ class VersionSet {
   // Per-level key at which the next compaction at that level should start.
   // Either an empty string, or a valid InternalKey.
   std::string compact_pointer_[config::kNumLevels];
-
-  // No copying allowed
-  VersionSet(const VersionSet&);
-  void operator=(const VersionSet&);
 };
 
 // A Compaction encapsulates information about a compaction.
diff --git a/db/version_set_test.cc b/db/version_set_test.cc
index 43b51d8..f7efe2b 100644
--- a/db/version_set_test.cc
+++ b/db/version_set_test.cc
@@ -11,9 +11,6 @@ namespace leveldb {
 
 class FindFileTest {
  public:
-  std::vector<FileMetaData*> files_;
-  bool disjoint_sorted_files_;
-
   FindFileTest() : disjoint_sorted_files_(true) {}
 
   ~FindFileTest() {
@@ -46,6 +43,11 @@ class FindFileTest {
                                  (smallest != nullptr ? &s : nullptr),
                                  (largest != nullptr ? &l : nullptr));
   }
+
+  bool disjoint_sorted_files_;
+
+ private:
+  std::vector<FileMetaData*> files_;
 };
 
 TEST(FindFileTest, Empty) {