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

7 files changed, 37 insertions, 34 deletions

diff --git a/include/leveldb/db.h b/include/leveldb/db.h
index 0b8dc24..e52a5b6 100644
--- a/include/leveldb/db.h
+++ b/include/leveldb/db.h
@@ -33,11 +33,11 @@ class LEVELDB_EXPORT Snapshot {
 
 // A range of keys
 struct LEVELDB_EXPORT Range {
-  Slice start;  // Included in the range
-  Slice limit;  // Not included in the range
-
   Range() {}
   Range(const Slice& s, const Slice& l) : start(s), limit(l) {}
+
+  Slice start;  // Included in the range
+  Slice limit;  // Not included in the range
 };
 
 // A DB is a persistent ordered map from keys to values.
diff --git a/include/leveldb/iterator.h b/include/leveldb/iterator.h
index 447e950..bb9a5df 100644
--- a/include/leveldb/iterator.h
+++ b/include/leveldb/iterator.h
@@ -84,12 +84,6 @@ class LEVELDB_EXPORT Iterator {
   // Cleanup functions are stored in a single-linked list.
   // The list's head node is inlined in the iterator.
   struct CleanupNode {
-    // The head node is used if the function pointer is not null.
-    CleanupFunction function;
-    void* arg1;
-    void* arg2;
-    CleanupNode* next;
-
     // True if the node is not used. Only head nodes might be unused.
     bool IsEmpty() const { return function == nullptr; }
     // Invokes the cleanup function.
@@ -97,6 +91,12 @@ class LEVELDB_EXPORT Iterator {
       assert(function != nullptr);
       (*function)(arg1, arg2);
     }
+
+    // The head node is used if the function pointer is not null.
+    CleanupFunction function;
+    void* arg1;
+    void* arg2;
+    CleanupNode* next;
   };
   CleanupNode cleanup_head_;
 };
diff --git a/include/leveldb/options.h b/include/leveldb/options.h
index 7e26dc6..b748772 100644
--- a/include/leveldb/options.h
+++ b/include/leveldb/options.h
@@ -31,6 +31,9 @@ enum CompressionType {
 
 // Options to control the behavior of a database (passed to DB::Open)
 struct LEVELDB_EXPORT Options {
+  // Create an Options object with default values for all fields.
+  Options();
+
   // -------------------
   // Parameters that affect behavior
 
@@ -137,13 +140,12 @@ struct LEVELDB_EXPORT Options {
   // Many applications will benefit from passing the result of
   // NewBloomFilterPolicy() here.
   const FilterPolicy* filter_policy = nullptr;
-
-  // Create an Options object with default values for all fields.
-  Options();
 };
 
 // Options that control read operations
 struct LEVELDB_EXPORT ReadOptions {
+  ReadOptions() = default;
+
   // If true, all data read from underlying storage will be
   // verified against corresponding checksums.
   bool verify_checksums = false;
@@ -157,12 +159,12 @@ struct LEVELDB_EXPORT ReadOptions {
   // not have been released).  If "snapshot" is null, use an implicit
   // snapshot of the state at the beginning of this read operation.
   const Snapshot* snapshot = nullptr;
-
-  ReadOptions() = default;
 };
 
 // Options that control write operations
 struct LEVELDB_EXPORT WriteOptions {
+  WriteOptions() = default;
+
   // If true, the write will be flushed from the operating system
   // buffer cache (by calling WritableFile::Sync()) before the write
   // is considered complete.  If this flag is true, writes will be
@@ -178,8 +180,6 @@ struct LEVELDB_EXPORT WriteOptions {
   // with sync==true has similar crash semantics to a "write()"
   // system call followed by "fsync()".
   bool sync = false;
-
-  WriteOptions() = default;
 };
 
 }  // namespace leveldb
diff --git a/include/leveldb/status.h b/include/leveldb/status.h
index 54cf377..e327314 100644
--- a/include/leveldb/status.h
+++ b/include/leveldb/status.h
@@ -76,13 +76,6 @@ class LEVELDB_EXPORT Status {
   std::string ToString() const;
 
  private:
-  // OK status has a null state_.  Otherwise, state_ is a new[] array
-  // of the following form:
-  //    state_[0..3] == length of message
-  //    state_[4]    == code
-  //    state_[5..]  == message
-  const char* state_;
-
   enum Code {
     kOk = 0,
     kNotFound = 1,
@@ -98,6 +91,13 @@ class LEVELDB_EXPORT Status {
 
   Status(Code code, const Slice& msg, const Slice& msg2);
   static const char* CopyState(const char* s);
+
+  // OK status has a null state_.  Otherwise, state_ is a new[] array
+  // of the following form:
+  //    state_[0..3] == length of message
+  //    state_[4]    == code
+  //    state_[5..]  == message
+  const char* state_;
 };
 
 inline Status::Status(const Status& rhs) {
diff --git a/include/leveldb/table.h b/include/leveldb/table.h
index 14a6a44..25c6013 100644
--- a/include/leveldb/table.h
+++ b/include/leveldb/table.h
@@ -41,7 +41,7 @@ class LEVELDB_EXPORT Table {
                      uint64_t file_size, Table** table);
 
   Table(const Table&) = delete;
-  void operator=(const Table&) = delete;
+  Table& operator=(const Table&) = delete;
 
   ~Table();
 
@@ -59,22 +59,24 @@ class LEVELDB_EXPORT Table {
   uint64_t ApproximateOffsetOf(const Slice& key) const;
 
  private:
+  friend class TableCache;
   struct Rep;
-  Rep* rep_;
 
-  explicit Table(Rep* rep) { rep_ = rep; }
   static Iterator* BlockReader(void*, const ReadOptions&, const Slice&);
 
+  explicit Table(Rep* rep) : rep_(rep) {}
+
   // Calls (*handle_result)(arg, ...) with the entry found after a call
   // to Seek(key).  May not make such a call if filter policy says
   // that key is not present.
-  friend class TableCache;
   Status InternalGet(const ReadOptions&, const Slice& key, void* arg,
                      void (*handle_result)(void* arg, const Slice& k,
                                            const Slice& v));
 
   void ReadMeta(const Footer& footer);
   void ReadFilter(const Slice& filter_handle_value);
+
+  Rep* const rep_;
 };
 
 }  // namespace leveldb
diff --git a/include/leveldb/table_builder.h b/include/leveldb/table_builder.h
index f8361fd..7d8896b 100644
--- a/include/leveldb/table_builder.h
+++ b/include/leveldb/table_builder.h
@@ -33,7 +33,7 @@ class LEVELDB_EXPORT TableBuilder {
   TableBuilder(const Options& options, WritableFile* file);
 
   TableBuilder(const TableBuilder&) = delete;
-  void operator=(const TableBuilder&) = delete;
+  TableBuilder& operator=(const TableBuilder&) = delete;
 
   // REQUIRES: Either Finish() or Abandon() has been called.
   ~TableBuilder();
diff --git a/include/leveldb/write_batch.h b/include/leveldb/write_batch.h
index 21f7c63..94d4115 100644
--- a/include/leveldb/write_batch.h
+++ b/include/leveldb/write_batch.h
@@ -32,6 +32,13 @@ class Slice;
 
 class LEVELDB_EXPORT WriteBatch {
  public:
+  class LEVELDB_EXPORT Handler {
+   public:
+    virtual ~Handler();
+    virtual void Put(const Slice& key, const Slice& value) = 0;
+    virtual void Delete(const Slice& key) = 0;
+  };
+
   WriteBatch();
 
   // Intentionally copyable.
@@ -63,12 +70,6 @@ class LEVELDB_EXPORT WriteBatch {
   void Append(const WriteBatch& source);
 
   // Support for iterating over the contents of a batch.
-  class LEVELDB_EXPORT Handler {
-   public:
-    virtual ~Handler();
-    virtual void Put(const Slice& key, const Slice& value) = 0;
-    virtual void Delete(const Slice& key) = 0;
-  };
   Status Iterate(Handler* handler) const;
 
  private: