Update to leveldb upstream using subtree merge

15 files changed, 533 insertions, 452 deletions

diff --git a/src/leveldb/include/leveldb/c.h b/src/leveldb/include/leveldb/c.h
index 1048fe3b86..02c79ba72e 100644
--- a/src/leveldb/include/leveldb/c.h
+++ b/src/leveldb/include/leveldb/c.h
@@ -32,7 +32,7 @@
   On failure, leveldb frees the old value of *errptr and
   set *errptr to a malloc()ed error message.
 
-  (4) Bools have the type unsigned char (0 == false; rest == true)
+  (4) Bools have the type uint8_t (0 == false; rest == true)
 
   (5) All of the pointer arguments must be non-NULL.
 */
@@ -48,225 +48,205 @@ extern "C" {
 #include <stddef.h>
 #include <stdint.h>
 
+#include "leveldb/export.h"
+
 /* Exported types */
 
-typedef struct leveldb_t               leveldb_t;
-typedef struct leveldb_cache_t         leveldb_cache_t;
-typedef struct leveldb_comparator_t    leveldb_comparator_t;
-typedef struct leveldb_env_t           leveldb_env_t;
-typedef struct leveldb_filelock_t      leveldb_filelock_t;
-typedef struct leveldb_filterpolicy_t  leveldb_filterpolicy_t;
-typedef struct leveldb_iterator_t      leveldb_iterator_t;
-typedef struct leveldb_logger_t        leveldb_logger_t;
-typedef struct leveldb_options_t       leveldb_options_t;
-typedef struct leveldb_randomfile_t    leveldb_randomfile_t;
-typedef struct leveldb_readoptions_t   leveldb_readoptions_t;
-typedef struct leveldb_seqfile_t       leveldb_seqfile_t;
-typedef struct leveldb_snapshot_t      leveldb_snapshot_t;
-typedef struct leveldb_writablefile_t  leveldb_writablefile_t;
-typedef struct leveldb_writebatch_t    leveldb_writebatch_t;
-typedef struct leveldb_writeoptions_t  leveldb_writeoptions_t;
+typedef struct leveldb_t leveldb_t;
+typedef struct leveldb_cache_t leveldb_cache_t;
+typedef struct leveldb_comparator_t leveldb_comparator_t;
+typedef struct leveldb_env_t leveldb_env_t;
+typedef struct leveldb_filelock_t leveldb_filelock_t;
+typedef struct leveldb_filterpolicy_t leveldb_filterpolicy_t;
+typedef struct leveldb_iterator_t leveldb_iterator_t;
+typedef struct leveldb_logger_t leveldb_logger_t;
+typedef struct leveldb_options_t leveldb_options_t;
+typedef struct leveldb_randomfile_t leveldb_randomfile_t;
+typedef struct leveldb_readoptions_t leveldb_readoptions_t;
+typedef struct leveldb_seqfile_t leveldb_seqfile_t;
+typedef struct leveldb_snapshot_t leveldb_snapshot_t;
+typedef struct leveldb_writablefile_t leveldb_writablefile_t;
+typedef struct leveldb_writebatch_t leveldb_writebatch_t;
+typedef struct leveldb_writeoptions_t leveldb_writeoptions_t;
 
 /* DB operations */
 
-extern leveldb_t* leveldb_open(
-    const leveldb_options_t* options,
-    const char* name,
-    char** errptr);
+LEVELDB_EXPORT leveldb_t* leveldb_open(const leveldb_options_t* options,
+                                       const char* name, char** errptr);
 
-extern void leveldb_close(leveldb_t* db);
+LEVELDB_EXPORT void leveldb_close(leveldb_t* db);
 
-extern void leveldb_put(
-    leveldb_t* db,
-    const leveldb_writeoptions_t* options,
-    const char* key, size_t keylen,
-    const char* val, size_t vallen,
-    char** errptr);
+LEVELDB_EXPORT void leveldb_put(leveldb_t* db,
+                                const leveldb_writeoptions_t* options,
+                                const char* key, size_t keylen, const char* val,
+                                size_t vallen, char** errptr);
 
-extern void leveldb_delete(
-    leveldb_t* db,
-    const leveldb_writeoptions_t* options,
-    const char* key, size_t keylen,
-    char** errptr);
+LEVELDB_EXPORT void leveldb_delete(leveldb_t* db,
+                                   const leveldb_writeoptions_t* options,
+                                   const char* key, size_t keylen,
+                                   char** errptr);
 
-extern void leveldb_write(
-    leveldb_t* db,
-    const leveldb_writeoptions_t* options,
-    leveldb_writebatch_t* batch,
-    char** errptr);
+LEVELDB_EXPORT void leveldb_write(leveldb_t* db,
+                                  const leveldb_writeoptions_t* options,
+                                  leveldb_writebatch_t* batch, char** errptr);
 
 /* Returns NULL if not found.  A malloc()ed array otherwise.
    Stores the length of the array in *vallen. */
-extern char* leveldb_get(
-    leveldb_t* db,
-    const leveldb_readoptions_t* options,
-    const char* key, size_t keylen,
-    size_t* vallen,
-    char** errptr);
+LEVELDB_EXPORT char* leveldb_get(leveldb_t* db,
+                                 const leveldb_readoptions_t* options,
+                                 const char* key, size_t keylen, size_t* vallen,
+                                 char** errptr);
 
-extern leveldb_iterator_t* leveldb_create_iterator(
-    leveldb_t* db,
-    const leveldb_readoptions_t* options);
+LEVELDB_EXPORT leveldb_iterator_t* leveldb_create_iterator(
+    leveldb_t* db, const leveldb_readoptions_t* options);
 
-extern const leveldb_snapshot_t* leveldb_create_snapshot(
-    leveldb_t* db);
+LEVELDB_EXPORT const leveldb_snapshot_t* leveldb_create_snapshot(leveldb_t* db);
 
-extern void leveldb_release_snapshot(
-    leveldb_t* db,
-    const leveldb_snapshot_t* snapshot);
+LEVELDB_EXPORT void leveldb_release_snapshot(
+    leveldb_t* db, const leveldb_snapshot_t* snapshot);
 
 /* Returns NULL if property name is unknown.
    Else returns a pointer to a malloc()-ed null-terminated value. */
-extern char* leveldb_property_value(
-    leveldb_t* db,
-    const char* propname);
-
-extern void leveldb_approximate_sizes(
-    leveldb_t* db,
-    int num_ranges,
-    const char* const* range_start_key, const size_t* range_start_key_len,
-    const char* const* range_limit_key, const size_t* range_limit_key_len,
-    uint64_t* sizes);
-
-extern void leveldb_compact_range(
-    leveldb_t* db,
-    const char* start_key, size_t start_key_len,
-    const char* limit_key, size_t limit_key_len);
+LEVELDB_EXPORT char* leveldb_property_value(leveldb_t* db,
+                                            const char* propname);
+
+LEVELDB_EXPORT void leveldb_approximate_sizes(
+    leveldb_t* db, int num_ranges, const char* const* range_start_key,
+    const size_t* range_start_key_len, const char* const* range_limit_key,
+    const size_t* range_limit_key_len, uint64_t* sizes);
+
+LEVELDB_EXPORT void leveldb_compact_range(leveldb_t* db, const char* start_key,
+                                          size_t start_key_len,
+                                          const char* limit_key,
+                                          size_t limit_key_len);
 
 /* Management operations */
 
-extern void leveldb_destroy_db(
-    const leveldb_options_t* options,
-    const char* name,
-    char** errptr);
+LEVELDB_EXPORT void leveldb_destroy_db(const leveldb_options_t* options,
+                                       const char* name, char** errptr);
 
-extern void leveldb_repair_db(
-    const leveldb_options_t* options,
-    const char* name,
-    char** errptr);
+LEVELDB_EXPORT void leveldb_repair_db(const leveldb_options_t* options,
+                                      const char* name, char** errptr);
 
 /* Iterator */
 
-extern void leveldb_iter_destroy(leveldb_iterator_t*);
-extern unsigned char leveldb_iter_valid(const leveldb_iterator_t*);
-extern void leveldb_iter_seek_to_first(leveldb_iterator_t*);
-extern void leveldb_iter_seek_to_last(leveldb_iterator_t*);
-extern void leveldb_iter_seek(leveldb_iterator_t*, const char* k, size_t klen);
-extern void leveldb_iter_next(leveldb_iterator_t*);
-extern void leveldb_iter_prev(leveldb_iterator_t*);
-extern const char* leveldb_iter_key(const leveldb_iterator_t*, size_t* klen);
-extern const char* leveldb_iter_value(const leveldb_iterator_t*, size_t* vlen);
-extern void leveldb_iter_get_error(const leveldb_iterator_t*, char** errptr);
+LEVELDB_EXPORT void leveldb_iter_destroy(leveldb_iterator_t*);
+LEVELDB_EXPORT uint8_t leveldb_iter_valid(const leveldb_iterator_t*);
+LEVELDB_EXPORT void leveldb_iter_seek_to_first(leveldb_iterator_t*);
+LEVELDB_EXPORT void leveldb_iter_seek_to_last(leveldb_iterator_t*);
+LEVELDB_EXPORT void leveldb_iter_seek(leveldb_iterator_t*, const char* k,
+                                      size_t klen);
+LEVELDB_EXPORT void leveldb_iter_next(leveldb_iterator_t*);
+LEVELDB_EXPORT void leveldb_iter_prev(leveldb_iterator_t*);
+LEVELDB_EXPORT const char* leveldb_iter_key(const leveldb_iterator_t*,
+                                            size_t* klen);
+LEVELDB_EXPORT const char* leveldb_iter_value(const leveldb_iterator_t*,
+                                              size_t* vlen);
+LEVELDB_EXPORT void leveldb_iter_get_error(const leveldb_iterator_t*,
+                                           char** errptr);
 
 /* Write batch */
 
-extern leveldb_writebatch_t* leveldb_writebatch_create();
-extern void leveldb_writebatch_destroy(leveldb_writebatch_t*);
-extern void leveldb_writebatch_clear(leveldb_writebatch_t*);
-extern void leveldb_writebatch_put(
-    leveldb_writebatch_t*,
-    const char* key, size_t klen,
-    const char* val, size_t vlen);
-extern void leveldb_writebatch_delete(
-    leveldb_writebatch_t*,
-    const char* key, size_t klen);
-extern void leveldb_writebatch_iterate(
-    leveldb_writebatch_t*,
-    void* state,
+LEVELDB_EXPORT leveldb_writebatch_t* leveldb_writebatch_create(void);
+LEVELDB_EXPORT void leveldb_writebatch_destroy(leveldb_writebatch_t*);
+LEVELDB_EXPORT void leveldb_writebatch_clear(leveldb_writebatch_t*);
+LEVELDB_EXPORT void leveldb_writebatch_put(leveldb_writebatch_t*,
+                                           const char* key, size_t klen,
+                                           const char* val, size_t vlen);
+LEVELDB_EXPORT void leveldb_writebatch_delete(leveldb_writebatch_t*,
+                                              const char* key, size_t klen);
+LEVELDB_EXPORT void leveldb_writebatch_iterate(
+    const leveldb_writebatch_t*, void* state,
     void (*put)(void*, const char* k, size_t klen, const char* v, size_t vlen),
     void (*deleted)(void*, const char* k, size_t klen));
+LEVELDB_EXPORT void leveldb_writebatch_append(
+    leveldb_writebatch_t* destination, const leveldb_writebatch_t* source);
 
 /* Options */
 
-extern leveldb_options_t* leveldb_options_create();
-extern void leveldb_options_destroy(leveldb_options_t*);
-extern void leveldb_options_set_comparator(
-    leveldb_options_t*,
-    leveldb_comparator_t*);
-extern void leveldb_options_set_filter_policy(
-    leveldb_options_t*,
-    leveldb_filterpolicy_t*);
-extern void leveldb_options_set_create_if_missing(
-    leveldb_options_t*, unsigned char);
-extern void leveldb_options_set_error_if_exists(
-    leveldb_options_t*, unsigned char);
-extern void leveldb_options_set_paranoid_checks(
-    leveldb_options_t*, unsigned char);
-extern void leveldb_options_set_env(leveldb_options_t*, leveldb_env_t*);
-extern void leveldb_options_set_info_log(leveldb_options_t*, leveldb_logger_t*);
-extern void leveldb_options_set_write_buffer_size(leveldb_options_t*, size_t);
-extern void leveldb_options_set_max_open_files(leveldb_options_t*, int);
-extern void leveldb_options_set_cache(leveldb_options_t*, leveldb_cache_t*);
-extern void leveldb_options_set_block_size(leveldb_options_t*, size_t);
-extern void leveldb_options_set_block_restart_interval(leveldb_options_t*, int);
-
-enum {
-  leveldb_no_compression = 0,
-  leveldb_snappy_compression = 1
-};
-extern void leveldb_options_set_compression(leveldb_options_t*, int);
+LEVELDB_EXPORT leveldb_options_t* leveldb_options_create(void);
+LEVELDB_EXPORT void leveldb_options_destroy(leveldb_options_t*);
+LEVELDB_EXPORT void leveldb_options_set_comparator(leveldb_options_t*,
+                                                   leveldb_comparator_t*);
+LEVELDB_EXPORT void leveldb_options_set_filter_policy(leveldb_options_t*,
+                                                      leveldb_filterpolicy_t*);
+LEVELDB_EXPORT void leveldb_options_set_create_if_missing(leveldb_options_t*,
+                                                          uint8_t);
+LEVELDB_EXPORT void leveldb_options_set_error_if_exists(leveldb_options_t*,
+                                                        uint8_t);
+LEVELDB_EXPORT void leveldb_options_set_paranoid_checks(leveldb_options_t*,
+                                                        uint8_t);
+LEVELDB_EXPORT void leveldb_options_set_env(leveldb_options_t*, leveldb_env_t*);
+LEVELDB_EXPORT void leveldb_options_set_info_log(leveldb_options_t*,
+                                                 leveldb_logger_t*);
+LEVELDB_EXPORT void leveldb_options_set_write_buffer_size(leveldb_options_t*,
+                                                          size_t);
+LEVELDB_EXPORT void leveldb_options_set_max_open_files(leveldb_options_t*, int);
+LEVELDB_EXPORT void leveldb_options_set_cache(leveldb_options_t*,
+                                              leveldb_cache_t*);
+LEVELDB_EXPORT void leveldb_options_set_block_size(leveldb_options_t*, size_t);
+LEVELDB_EXPORT void leveldb_options_set_block_restart_interval(
+    leveldb_options_t*, int);
+LEVELDB_EXPORT void leveldb_options_set_max_file_size(leveldb_options_t*,
+                                                      size_t);
+
+enum { leveldb_no_compression = 0, leveldb_snappy_compression = 1 };
+LEVELDB_EXPORT void leveldb_options_set_compression(leveldb_options_t*, int);
 
 /* Comparator */
 
-extern leveldb_comparator_t* leveldb_comparator_create(
-    void* state,
-    void (*destructor)(void*),
-    int (*compare)(
-        void*,
-        const char* a, size_t alen,
-        const char* b, size_t blen),
+LEVELDB_EXPORT leveldb_comparator_t* leveldb_comparator_create(
+    void* state, void (*destructor)(void*),
+    int (*compare)(void*, const char* a, size_t alen, const char* b,
+                   size_t blen),
     const char* (*name)(void*));
-extern void leveldb_comparator_destroy(leveldb_comparator_t*);
+LEVELDB_EXPORT void leveldb_comparator_destroy(leveldb_comparator_t*);
 
 /* Filter policy */
 
-extern leveldb_filterpolicy_t* leveldb_filterpolicy_create(
-    void* state,
-    void (*destructor)(void*),
-    char* (*create_filter)(
-        void*,
-        const char* const* key_array, const size_t* key_length_array,
-        int num_keys,
-        size_t* filter_length),
-    unsigned char (*key_may_match)(
-        void*,
-        const char* key, size_t length,
-        const char* filter, size_t filter_length),
+LEVELDB_EXPORT leveldb_filterpolicy_t* leveldb_filterpolicy_create(
+    void* state, void (*destructor)(void*),
+    char* (*create_filter)(void*, const char* const* key_array,
+                           const size_t* key_length_array, int num_keys,
+                           size_t* filter_length),
+    uint8_t (*key_may_match)(void*, const char* key, size_t length,
+                             const char* filter, size_t filter_length),
     const char* (*name)(void*));
-extern void leveldb_filterpolicy_destroy(leveldb_filterpolicy_t*);
+LEVELDB_EXPORT void leveldb_filterpolicy_destroy(leveldb_filterpolicy_t*);
 
-extern leveldb_filterpolicy_t* leveldb_filterpolicy_create_bloom(
+LEVELDB_EXPORT leveldb_filterpolicy_t* leveldb_filterpolicy_create_bloom(
     int bits_per_key);
 
 /* Read options */
 
-extern leveldb_readoptions_t* leveldb_readoptions_create();
-extern void leveldb_readoptions_destroy(leveldb_readoptions_t*);
-extern void leveldb_readoptions_set_verify_checksums(
-    leveldb_readoptions_t*,
-    unsigned char);
-extern void leveldb_readoptions_set_fill_cache(
-    leveldb_readoptions_t*, unsigned char);
-extern void leveldb_readoptions_set_snapshot(
-    leveldb_readoptions_t*,
-    const leveldb_snapshot_t*);
+LEVELDB_EXPORT leveldb_readoptions_t* leveldb_readoptions_create(void);
+LEVELDB_EXPORT void leveldb_readoptions_destroy(leveldb_readoptions_t*);
+LEVELDB_EXPORT void leveldb_readoptions_set_verify_checksums(
+    leveldb_readoptions_t*, uint8_t);
+LEVELDB_EXPORT void leveldb_readoptions_set_fill_cache(leveldb_readoptions_t*,
+                                                       uint8_t);
+LEVELDB_EXPORT void leveldb_readoptions_set_snapshot(leveldb_readoptions_t*,
+                                                     const leveldb_snapshot_t*);
 
 /* Write options */
 
-extern leveldb_writeoptions_t* leveldb_writeoptions_create();
-extern void leveldb_writeoptions_destroy(leveldb_writeoptions_t*);
-extern void leveldb_writeoptions_set_sync(
-    leveldb_writeoptions_t*, unsigned char);
+LEVELDB_EXPORT leveldb_writeoptions_t* leveldb_writeoptions_create(void);
+LEVELDB_EXPORT void leveldb_writeoptions_destroy(leveldb_writeoptions_t*);
+LEVELDB_EXPORT void leveldb_writeoptions_set_sync(leveldb_writeoptions_t*,
+                                                  uint8_t);
 
 /* Cache */
 
-extern leveldb_cache_t* leveldb_cache_create_lru(size_t capacity);
-extern void leveldb_cache_destroy(leveldb_cache_t* cache);
+LEVELDB_EXPORT leveldb_cache_t* leveldb_cache_create_lru(size_t capacity);
+LEVELDB_EXPORT void leveldb_cache_destroy(leveldb_cache_t* cache);
 
 /* Env */
 
-extern leveldb_env_t* leveldb_create_default_env();
-extern void leveldb_env_destroy(leveldb_env_t*);
+LEVELDB_EXPORT leveldb_env_t* leveldb_create_default_env(void);
+LEVELDB_EXPORT void leveldb_env_destroy(leveldb_env_t*);
+
+/* If not NULL, the returned buffer must be released using leveldb_free(). */
+LEVELDB_EXPORT char* leveldb_env_get_test_directory(leveldb_env_t*);
 
 /* Utility */
 
@@ -275,16 +255,16 @@ extern void leveldb_env_destroy(leveldb_env_t*);
    in this file.  Note that in certain cases (typically on Windows), you
    may need to call this routine instead of free(ptr) to dispose of
    malloc()-ed memory returned by this library. */
-extern void leveldb_free(void* ptr);
+LEVELDB_EXPORT void leveldb_free(void* ptr);
 
 /* Return the major version number for this release. */
-extern int leveldb_major_version();
+LEVELDB_EXPORT int leveldb_major_version(void);
 
 /* Return the minor version number for this release. */
-extern int leveldb_minor_version();
+LEVELDB_EXPORT int leveldb_minor_version(void);
 
 #ifdef __cplusplus
-}  /* end extern "C" */
+} /* end extern "C" */
 #endif
 
-#endif  /* STORAGE_LEVELDB_INCLUDE_C_H_ */
+#endif /* STORAGE_LEVELDB_INCLUDE_C_H_ */
diff --git a/src/leveldb/include/leveldb/cache.h b/src/leveldb/include/leveldb/cache.h
index 6819d5bc49..7d1a221193 100644
--- a/src/leveldb/include/leveldb/cache.h
+++ b/src/leveldb/include/leveldb/cache.h
@@ -19,26 +19,31 @@
 #define STORAGE_LEVELDB_INCLUDE_CACHE_H_
 
 #include <stdint.h>
+
+#include "leveldb/export.h"
 #include "leveldb/slice.h"
 
 namespace leveldb {
 
-class Cache;
+class LEVELDB_EXPORT Cache;
 
 // Create a new cache with a fixed size capacity.  This implementation
 // of Cache uses a least-recently-used eviction policy.
-extern Cache* NewLRUCache(size_t capacity);
+LEVELDB_EXPORT Cache* NewLRUCache(size_t capacity);
 
-class Cache {
+class LEVELDB_EXPORT Cache {
  public:
-  Cache() { }
+  Cache() = default;
+
+  Cache(const Cache&) = delete;
+  Cache& operator=(const Cache&) = delete;
 
   // Destroys all existing entries by calling the "deleter"
   // function that was passed to the constructor.
   virtual ~Cache();
 
   // Opaque handle to an entry stored in the cache.
-  struct Handle { };
+  struct Handle {};
 
   // Insert a mapping from key->value into the cache and assign it
   // the specified charge against the total cache capacity.
@@ -52,7 +57,7 @@ class Cache {
   virtual Handle* Insert(const Slice& key, void* value, size_t charge,
                          void (*deleter)(const Slice& key, void* value)) = 0;
 
-  // If the cache has no mapping for "key", returns NULL.
+  // If the cache has no mapping for "key", returns nullptr.
   //
   // Else return a handle that corresponds to the mapping.  The caller
   // must call this->Release(handle) when the returned mapping is no
@@ -99,10 +104,6 @@ class Cache {
 
   struct Rep;
   Rep* rep_;
-
-  // No copying allowed
-  Cache(const Cache&);
-  void operator=(const Cache&);
 };
 
 }  // namespace leveldb
diff --git a/src/leveldb/include/leveldb/comparator.h b/src/leveldb/include/leveldb/comparator.h
index 556b984c76..a85b51ebd8 100644
--- a/src/leveldb/include/leveldb/comparator.h
+++ b/src/leveldb/include/leveldb/comparator.h
@@ -7,6 +7,8 @@
 
 #include <string>
 
+#include "leveldb/export.h"
+
 namespace leveldb {
 
 class Slice;
@@ -15,7 +17,7 @@ class Slice;
 // used as keys in an sstable or a database.  A Comparator implementation
 // must be thread-safe since leveldb may invoke its methods concurrently
 // from multiple threads.
-class Comparator {
+class LEVELDB_EXPORT Comparator {
  public:
   virtual ~Comparator();
 
@@ -43,9 +45,8 @@ class Comparator {
   // If *start < limit, changes *start to a short string in [start,limit).
   // Simple comparator implementations may return with *start unchanged,
   // i.e., an implementation of this method that does nothing is correct.
-  virtual void FindShortestSeparator(
-      std::string* start,
-      const Slice& limit) const = 0;
+  virtual void FindShortestSeparator(std::string* start,
+                                     const Slice& limit) const = 0;
 
   // Changes *key to a short string >= *key.
   // Simple comparator implementations may return with *key unchanged,
@@ -56,7 +57,7 @@ class Comparator {
 // Return a builtin comparator that uses lexicographic byte-wise
 // ordering.  The result remains the property of this module and
 // must not be deleted.
-extern const Comparator* BytewiseComparator();
+LEVELDB_EXPORT const Comparator* BytewiseComparator();
 
 }  // namespace leveldb
 
diff --git a/src/leveldb/include/leveldb/db.h b/src/leveldb/include/leveldb/db.h
index bfab10a0b7..b73014a221 100644
--- a/src/leveldb/include/leveldb/db.h
+++ b/src/leveldb/include/leveldb/db.h
@@ -7,14 +7,16 @@
 
 #include <stdint.h>
 #include <stdio.h>
+
+#include "leveldb/export.h"
 #include "leveldb/iterator.h"
 #include "leveldb/options.h"
 
 namespace leveldb {
 
-// Update Makefile if you change these
+// Update CMakeLists.txt if you change these
 static const int kMajorVersion = 1;
-static const int kMinorVersion = 20;
+static const int kMinorVersion = 22;
 
 struct Options;
 struct ReadOptions;
@@ -24,42 +26,44 @@ class WriteBatch;
 // Abstract handle to particular state of a DB.
 // A Snapshot is an immutable object and can therefore be safely
 // accessed from multiple threads without any external synchronization.
-class Snapshot {
+class LEVELDB_EXPORT Snapshot {
  protected:
   virtual ~Snapshot();
 };
 
 // A range of keys
-struct Range {
-  Slice start;          // Included in the range
-  Slice limit;          // Not included in the range
+struct LEVELDB_EXPORT Range {
+  Range() = default;
+  Range(const Slice& s, const Slice& l) : start(s), limit(l) {}
 
-  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.
 // A DB is safe for concurrent access from multiple threads without
 // any external synchronization.
-class DB {
+class LEVELDB_EXPORT DB {
  public:
   // Open the database with the specified "name".
   // Stores a pointer to a heap-allocated database in *dbptr and returns
   // OK on success.
-  // Stores NULL in *dbptr and returns a non-OK status on error.
+  // Stores nullptr in *dbptr and returns a non-OK status on error.
   // Caller should delete *dbptr when it is no longer needed.
-  static Status Open(const Options& options,
-                     const std::string& name,
+  static Status Open(const Options& options, const std::string& name,
                      DB** dbptr);
 
-  DB() { }
+  DB() = default;
+
+  DB(const DB&) = delete;
+  DB& operator=(const DB&) = delete;
+
   virtual ~DB();
 
   // Set the database entry for "key" to "value".  Returns OK on success,
   // and a non-OK status on error.
   // Note: consider setting options.sync = true.
-  virtual Status Put(const WriteOptions& options,
-                     const Slice& key,
+  virtual Status Put(const WriteOptions& options, const Slice& key,
                      const Slice& value) = 0;
 
   // Remove the database entry (if any) for "key".  Returns OK on
@@ -80,8 +84,8 @@ class DB {
   // a status for which Status::IsNotFound() returns true.
   //
   // May return some other Status on an error.
-  virtual Status Get(const ReadOptions& options,
-                     const Slice& key, std::string* value) = 0;
+  virtual Status Get(const ReadOptions& options, const Slice& key,
+                     std::string* value) = 0;
 
   // Return a heap-allocated iterator over the contents of the database.
   // The result of NewIterator() is initially invalid (caller must
@@ -136,27 +140,27 @@ class DB {
   // needed to access the data.  This operation should typically only
   // be invoked by users who understand the underlying implementation.
   //
-  // begin==NULL is treated as a key before all keys in the database.
-  // end==NULL is treated as a key after all keys in the database.
+  // begin==nullptr is treated as a key before all keys in the database.
+  // end==nullptr is treated as a key after all keys in the database.
   // Therefore the following call will compact the entire database:
-  //    db->CompactRange(NULL, NULL);
+  //    db->CompactRange(nullptr, nullptr);
   virtual void CompactRange(const Slice* begin, const Slice* end) = 0;
-
- private:
-  // No copying allowed
-  DB(const DB&);
-  void operator=(const DB&);
 };
 
 // Destroy the contents of the specified database.
 // Be very careful using this method.
-Status DestroyDB(const std::string& name, const Options& options);
+//
+// Note: For backwards compatibility, if DestroyDB is unable to list the
+// database files, Status::OK() will still be returned masking this failure.
+LEVELDB_EXPORT Status DestroyDB(const std::string& name,
+                                const Options& options);
 
 // If a DB cannot be opened, you may attempt to call this method to
 // resurrect as much of the contents of the database as possible.
 // Some data may be lost, so be careful when calling this function
 // on a database that contains important information.
-Status RepairDB(const std::string& dbname, const Options& options);
+LEVELDB_EXPORT Status RepairDB(const std::string& dbname,
+                               const Options& options);
 
 }  // namespace leveldb
 
diff --git a/src/leveldb/include/leveldb/dumpfile.h b/src/leveldb/include/leveldb/dumpfile.h
index 3f97fda16b..a58bc6b36c 100644
--- a/src/leveldb/include/leveldb/dumpfile.h
+++ b/src/leveldb/include/leveldb/dumpfile.h
@@ -6,7 +6,9 @@
 #define STORAGE_LEVELDB_INCLUDE_DUMPFILE_H_
 
 #include <string>
+
 #include "leveldb/env.h"
+#include "leveldb/export.h"
 #include "leveldb/status.h"
 
 namespace leveldb {
@@ -18,7 +20,8 @@ namespace leveldb {
 //
 // Returns a non-OK result if fname does not name a leveldb storage
 // file, or if the file cannot be read.
-Status DumpFile(Env* env, const std::string& fname, WritableFile* dst);
+LEVELDB_EXPORT Status DumpFile(Env* env, const std::string& fname,
+                               WritableFile* dst);
 
 }  // namespace leveldb
 
diff --git a/src/leveldb/include/leveldb/env.h b/src/leveldb/include/leveldb/env.h
index 275d441eae..96c21b3966 100644
--- a/src/leveldb/include/leveldb/env.h
+++ b/src/leveldb/include/leveldb/env.h
@@ -13,12 +13,36 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_ENV_H_
 #define STORAGE_LEVELDB_INCLUDE_ENV_H_
 
-#include <string>
-#include <vector>
 #include <stdarg.h>
 #include <stdint.h>
+
+#include <string>
+#include <vector>
+
+#include "leveldb/export.h"
 #include "leveldb/status.h"
 
+#if defined(_WIN32)
+// The leveldb::Env class below contains a DeleteFile method.
+// At the same time, <windows.h>, a fairly popular header
+// file for Windows applications, defines a DeleteFile macro.
+//
+// Without any intervention on our part, the result of this
+// unfortunate coincidence is that the name of the
+// leveldb::Env::DeleteFile method seen by the compiler depends on
+// whether <windows.h> was included before or after the LevelDB
+// headers.
+//
+// To avoid headaches, we undefined DeleteFile (if defined) and
+// redefine it at the bottom of this file. This way <windows.h>
+// can be included before this file (or not at all) and the
+// exported method will always be leveldb::Env::DeleteFile.
+#if defined(DeleteFile)
+#undef DeleteFile
+#define LEVELDB_DELETEFILE_UNDEFINED
+#endif  // defined(DeleteFile)
+#endif  // defined(_WIN32)
+
 namespace leveldb {
 
 class FileLock;
@@ -28,9 +52,13 @@ class SequentialFile;
 class Slice;
 class WritableFile;
 
-class Env {
+class LEVELDB_EXPORT Env {
  public:
-  Env() { }
+  Env() = default;
+
+  Env(const Env&) = delete;
+  Env& operator=(const Env&) = delete;
+
   virtual ~Env();
 
   // Return a default environment suitable for the current operating
@@ -40,20 +68,22 @@ class Env {
   // The result of Default() belongs to leveldb and must never be deleted.
   static Env* Default();
 
-  // Create a brand new sequentially-readable file with the specified name.
+  // Create an object that sequentially reads the file with the specified name.
   // On success, stores a pointer to the new file in *result and returns OK.
-  // On failure stores NULL in *result and returns non-OK.  If the file does
-  // not exist, returns a non-OK status.
+  // On failure stores nullptr in *result and returns non-OK.  If the file does
+  // not exist, returns a non-OK status.  Implementations should return a
+  // NotFound status when the file does not exist.
   //
   // The returned file will only be accessed by one thread at a time.
   virtual Status NewSequentialFile(const std::string& fname,
                                    SequentialFile** result) = 0;
 
-  // Create a brand new random access read-only file with the
+  // Create an object supporting random-access reads from the file with the
   // specified name.  On success, stores a pointer to the new file in
-  // *result and returns OK.  On failure stores NULL in *result and
+  // *result and returns OK.  On failure stores nullptr in *result and
   // returns non-OK.  If the file does not exist, returns a non-OK
-  // status.
+  // status.  Implementations should return a NotFound status when the file does
+  // not exist.
   //
   // The returned file may be concurrently accessed by multiple threads.
   virtual Status NewRandomAccessFile(const std::string& fname,
@@ -62,7 +92,7 @@ class Env {
   // Create an object that writes to a new file with the specified
   // name.  Deletes any existing file with the same name and creates a
   // new file.  On success, stores a pointer to the new file in
-  // *result and returns OK.  On failure stores NULL in *result and
+  // *result and returns OK.  On failure stores nullptr in *result and
   // returns non-OK.
   //
   // The returned file will only be accessed by one thread at a time.
@@ -72,7 +102,7 @@ class Env {
   // Create an object that either appends to an existing file, or
   // writes to a new file (if the file does not exist to begin with).
   // On success, stores a pointer to the new file in *result and
-  // returns OK.  On failure stores NULL in *result and returns
+  // returns OK.  On failure stores nullptr in *result and returns
   // non-OK.
   //
   // The returned file will only be accessed by one thread at a time.
@@ -110,7 +140,7 @@ class Env {
                             const std::string& target) = 0;
 
   // Lock the specified file.  Used to prevent concurrent access to
-  // the same db by multiple processes.  On failure, stores NULL in
+  // the same db by multiple processes.  On failure, stores nullptr in
   // *lock and returns non-OK.
   //
   // On success, stores a pointer to the object that represents the
@@ -136,16 +166,14 @@ class Env {
   // added to the same Env may run concurrently in different threads.
   // I.e., the caller may not assume that background work items are
   // serialized.
-  virtual void Schedule(
-      void (*function)(void* arg),
-      void* arg) = 0;
+  virtual void Schedule(void (*function)(void* arg), void* arg) = 0;
 
   // Start a new thread, invoking "function(arg)" within the new thread.
   // When "function(arg)" returns, the thread will be destroyed.
   virtual void StartThread(void (*function)(void* arg), void* arg) = 0;
 
   // *path is set to a temporary directory that can be used for testing. It may
-  // or many not have just been created. The directory may or may not differ
+  // or may not have just been created. The directory may or may not differ
   // between runs of the same process, but subsequent calls will return the
   // same directory.
   virtual Status GetTestDirectory(std::string* path) = 0;
@@ -159,17 +187,16 @@ class Env {
 
   // Sleep/delay the thread for the prescribed number of micro-seconds.
   virtual void SleepForMicroseconds(int micros) = 0;
-
- private:
-  // No copying allowed
-  Env(const Env&);
-  void operator=(const Env&);
 };
 
 // A file abstraction for reading sequentially through a file
-class SequentialFile {
+class LEVELDB_EXPORT SequentialFile {
  public:
-  SequentialFile() { }
+  SequentialFile() = default;
+
+  SequentialFile(const SequentialFile&) = delete;
+  SequentialFile& operator=(const SequentialFile&) = delete;
+
   virtual ~SequentialFile();
 
   // Read up to "n" bytes from the file.  "scratch[0..n-1]" may be
@@ -193,17 +220,16 @@ class SequentialFile {
 
   // Get a name for the file, only for error reporting
   virtual std::string GetName() const = 0;
-
- private:
-  // No copying allowed
-  SequentialFile(const SequentialFile&);
-  void operator=(const SequentialFile&);
 };
 
 // A file abstraction for randomly reading the contents of a file.
-class RandomAccessFile {
+class LEVELDB_EXPORT RandomAccessFile {
  public:
-  RandomAccessFile() { }
+  RandomAccessFile() = default;
+
+  RandomAccessFile(const RandomAccessFile&) = delete;
+  RandomAccessFile& operator=(const RandomAccessFile&) = delete;
+
   virtual ~RandomAccessFile();
 
   // Read up to "n" bytes from the file starting at "offset".
@@ -220,19 +246,18 @@ class RandomAccessFile {
 
   // Get a name for the file, only for error reporting
   virtual std::string GetName() const = 0;
-
- private:
-  // No copying allowed
-  RandomAccessFile(const RandomAccessFile&);
-  void operator=(const RandomAccessFile&);
 };
 
 // A file abstraction for sequential writing.  The implementation
 // must provide buffering since callers may append small fragments
 // at a time to the file.
-class WritableFile {
+class LEVELDB_EXPORT WritableFile {
  public:
-  WritableFile() { }
+  WritableFile() = default;
+
+  WritableFile(const WritableFile&) = delete;
+  WritableFile& operator=(const WritableFile&) = delete;
+
   virtual ~WritableFile();
 
   virtual Status Append(const Slice& data) = 0;
@@ -242,119 +267,130 @@ class WritableFile {
 
   // Get a name for the file, only for error reporting
   virtual std::string GetName() const = 0;
-
- private:
-  // No copying allowed
-  WritableFile(const WritableFile&);
-  void operator=(const WritableFile&);
 };
 
 // An interface for writing log messages.
-class Logger {
+class LEVELDB_EXPORT Logger {
  public:
-  Logger() { }
+  Logger() = default;
+
+  Logger(const Logger&) = delete;
+  Logger& operator=(const Logger&) = delete;
+
   virtual ~Logger();
 
   // Write an entry to the log file with the specified format.
   virtual void Logv(const char* format, va_list ap) = 0;
-
- private:
-  // No copying allowed
-  Logger(const Logger&);
-  void operator=(const Logger&);
 };
 
-
 // Identifies a locked file.
-class FileLock {
+class LEVELDB_EXPORT FileLock {
  public:
-  FileLock() { }
+  FileLock() = default;
+
+  FileLock(const FileLock&) = delete;
+  FileLock& operator=(const FileLock&) = delete;
+
   virtual ~FileLock();
- private:
-  // No copying allowed
-  FileLock(const FileLock&);
-  void operator=(const FileLock&);
 };
 
-// Log the specified data to *info_log if info_log is non-NULL.
-extern void Log(Logger* info_log, const char* format, ...)
-#   if defined(__GNUC__) || defined(__clang__)
-    __attribute__((__format__ (__printf__, 2, 3)))
-#   endif
+// Log the specified data to *info_log if info_log is non-null.
+void Log(Logger* info_log, const char* format, ...)
+#if defined(__GNUC__) || defined(__clang__)
+    __attribute__((__format__(__printf__, 2, 3)))
+#endif
     ;
 
 // A utility routine: write "data" to the named file.
-extern Status WriteStringToFile(Env* env, const Slice& data,
-                                const std::string& fname);
+LEVELDB_EXPORT Status WriteStringToFile(Env* env, const Slice& data,
+                                        const std::string& fname);
 
 // A utility routine: read contents of named file into *data
-extern Status ReadFileToString(Env* env, const std::string& fname,
-                               std::string* data);
+LEVELDB_EXPORT Status ReadFileToString(Env* env, const std::string& fname,
+                                       std::string* data);
 
 // An implementation of Env that forwards all calls to another Env.
 // May be useful to clients who wish to override just part of the
 // functionality of another Env.
-class EnvWrapper : public Env {
+class LEVELDB_EXPORT EnvWrapper : public Env {
  public:
-  // Initialize an EnvWrapper that delegates all calls to *t
-  explicit EnvWrapper(Env* t) : target_(t) { }
+  // Initialize an EnvWrapper that delegates all calls to *t.
+  explicit EnvWrapper(Env* t) : target_(t) {}
   virtual ~EnvWrapper();
 
-  // Return the target to which this Env forwards all calls
+  // Return the target to which this Env forwards all calls.
   Env* target() const { return target_; }
 
-  // The following text is boilerplate that forwards all methods to target()
-  Status NewSequentialFile(const std::string& f, SequentialFile** r) {
+  // The following text is boilerplate that forwards all methods to target().
+  Status NewSequentialFile(const std::string& f, SequentialFile** r) override {
     return target_->NewSequentialFile(f, r);
   }
-  Status NewRandomAccessFile(const std::string& f, RandomAccessFile** r) {
+  Status NewRandomAccessFile(const std::string& f,
+                             RandomAccessFile** r) override {
     return target_->NewRandomAccessFile(f, r);
   }
-  Status NewWritableFile(const std::string& f, WritableFile** r) {
+  Status NewWritableFile(const std::string& f, WritableFile** r) override {
     return target_->NewWritableFile(f, r);
   }
-  Status NewAppendableFile(const std::string& f, WritableFile** r) {
+  Status NewAppendableFile(const std::string& f, WritableFile** r) override {
     return target_->NewAppendableFile(f, r);
   }
-  bool FileExists(const std::string& f) { return target_->FileExists(f); }
-  Status GetChildren(const std::string& dir, std::vector<std::string>* r) {
+  bool FileExists(const std::string& f) override {
+    return target_->FileExists(f);
+  }
+  Status GetChildren(const std::string& dir,
+                     std::vector<std::string>* r) override {
     return target_->GetChildren(dir, r);
   }
-  Status DeleteFile(const std::string& f) { return target_->DeleteFile(f); }
-  Status CreateDir(const std::string& d) { return target_->CreateDir(d); }
-  Status DeleteDir(const std::string& d) { return target_->DeleteDir(d); }
-  Status GetFileSize(const std::string& f, uint64_t* s) {
+  Status DeleteFile(const std::string& f) override {
+    return target_->DeleteFile(f);
+  }
+  Status CreateDir(const std::string& d) override {
+    return target_->CreateDir(d);
+  }
+  Status DeleteDir(const std::string& d) override {
+    return target_->DeleteDir(d);
+  }
+  Status GetFileSize(const std::string& f, uint64_t* s) override {
     return target_->GetFileSize(f, s);
   }
-  Status RenameFile(const std::string& s, const std::string& t) {
+  Status RenameFile(const std::string& s, const std::string& t) override {
     return target_->RenameFile(s, t);
   }
-  Status LockFile(const std::string& f, FileLock** l) {
+  Status LockFile(const std::string& f, FileLock** l) override {
     return target_->LockFile(f, l);
   }
-  Status UnlockFile(FileLock* l) { return target_->UnlockFile(l); }
-  void Schedule(void (*f)(void*), void* a) {
+  Status UnlockFile(FileLock* l) override { return target_->UnlockFile(l); }
+  void Schedule(void (*f)(void*), void* a) override {
     return target_->Schedule(f, a);
   }
-  void StartThread(void (*f)(void*), void* a) {
+  void StartThread(void (*f)(void*), void* a) override {
     return target_->StartThread(f, a);
   }
-  virtual Status GetTestDirectory(std::string* path) {
+  Status GetTestDirectory(std::string* path) override {
     return target_->GetTestDirectory(path);
   }
-  virtual Status NewLogger(const std::string& fname, Logger** result) {
+  Status NewLogger(const std::string& fname, Logger** result) override {
     return target_->NewLogger(fname, result);
   }
-  uint64_t NowMicros() {
-    return target_->NowMicros();
-  }
-  void SleepForMicroseconds(int micros) {
+  uint64_t NowMicros() override { return target_->NowMicros(); }
+  void SleepForMicroseconds(int micros) override {
     target_->SleepForMicroseconds(micros);
   }
+
  private:
   Env* target_;
 };
 
 }  // namespace leveldb
 
+// Redefine DeleteFile if necessary.
+#if defined(_WIN32) && defined(LEVELDB_DELETEFILE_UNDEFINED)
+#if defined(UNICODE)
+#define DeleteFile DeleteFileW
+#else
+#define DeleteFile DeleteFileA
+#endif  // defined(UNICODE)
+#endif  // defined(_WIN32) && defined(LEVELDB_DELETEFILE_UNDEFINED)
+
 #endif  // STORAGE_LEVELDB_INCLUDE_ENV_H_
diff --git a/src/leveldb/include/leveldb/export.h b/src/leveldb/include/leveldb/export.h
new file mode 100644
index 0000000000..6ba9b183da
--- /dev/null
+++ b/src/leveldb/include/leveldb/export.h
@@ -0,0 +1,33 @@
+// Copyright (c) 2017 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 STORAGE_LEVELDB_INCLUDE_EXPORT_H_
+#define STORAGE_LEVELDB_INCLUDE_EXPORT_H_
+
+#if !defined(LEVELDB_EXPORT)
+
+#if defined(LEVELDB_SHARED_LIBRARY)
+#if defined(_WIN32)
+
+#if defined(LEVELDB_COMPILE_LIBRARY)
+#define LEVELDB_EXPORT __declspec(dllexport)
+#else
+#define LEVELDB_EXPORT __declspec(dllimport)
+#endif  // defined(LEVELDB_COMPILE_LIBRARY)
+
+#else  // defined(_WIN32)
+#if defined(LEVELDB_COMPILE_LIBRARY)
+#define LEVELDB_EXPORT __attribute__((visibility("default")))
+#else
+#define LEVELDB_EXPORT
+#endif
+#endif  // defined(_WIN32)
+
+#else  // defined(LEVELDB_SHARED_LIBRARY)
+#define LEVELDB_EXPORT
+#endif
+
+#endif  // !defined(LEVELDB_EXPORT)
+
+#endif  // STORAGE_LEVELDB_INCLUDE_EXPORT_H_
diff --git a/src/leveldb/include/leveldb/filter_policy.h b/src/leveldb/include/leveldb/filter_policy.h
index 1fba08001f..49c8eda776 100644
--- a/src/leveldb/include/leveldb/filter_policy.h
+++ b/src/leveldb/include/leveldb/filter_policy.h
@@ -18,11 +18,13 @@
 
 #include <string>
 
+#include "leveldb/export.h"
+
 namespace leveldb {
 
 class Slice;
 
-class FilterPolicy {
+class LEVELDB_EXPORT FilterPolicy {
  public:
   virtual ~FilterPolicy();
 
@@ -38,8 +40,8 @@ class FilterPolicy {
   //
   // Warning: do not change the initial contents of *dst.  Instead,
   // append the newly constructed filter to *dst.
-  virtual void CreateFilter(const Slice* keys, int n, std::string* dst)
-      const = 0;
+  virtual void CreateFilter(const Slice* keys, int n,
+                            std::string* dst) const = 0;
 
   // "filter" contains the data appended by a preceding call to
   // CreateFilter() on this class.  This method must return true if
@@ -63,8 +65,8 @@ class FilterPolicy {
 // ignores trailing spaces, it would be incorrect to use a
 // FilterPolicy (like NewBloomFilterPolicy) that does not ignore
 // trailing spaces in keys.
-extern const FilterPolicy* NewBloomFilterPolicy(int bits_per_key);
+LEVELDB_EXPORT const FilterPolicy* NewBloomFilterPolicy(int bits_per_key);
 
-}
+}  // namespace leveldb
 
 #endif  // STORAGE_LEVELDB_INCLUDE_FILTER_POLICY_H_
diff --git a/src/leveldb/include/leveldb/iterator.h b/src/leveldb/include/leveldb/iterator.h
index da631ed9d8..bb9a5df8f5 100644
--- a/src/leveldb/include/leveldb/iterator.h
+++ b/src/leveldb/include/leveldb/iterator.h
@@ -15,14 +15,19 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_ITERATOR_H_
 #define STORAGE_LEVELDB_INCLUDE_ITERATOR_H_
 
+#include "leveldb/export.h"
 #include "leveldb/slice.h"
 #include "leveldb/status.h"
 
 namespace leveldb {
 
-class Iterator {
+class LEVELDB_EXPORT Iterator {
  public:
   Iterator();
+
+  Iterator(const Iterator&) = delete;
+  Iterator& operator=(const Iterator&) = delete;
+
   virtual ~Iterator();
 
   // An iterator is either positioned at a key/value pair, or
@@ -72,28 +77,35 @@ class Iterator {
   //
   // Note that unlike all of the preceding methods, this method is
   // not abstract and therefore clients should not override it.
-  typedef void (*CleanupFunction)(void* arg1, void* arg2);
+  using CleanupFunction = void (*)(void* arg1, void* arg2);
   void RegisterCleanup(CleanupFunction function, void* arg1, void* arg2);
 
  private:
-  struct Cleanup {
+  // Cleanup functions are stored in a single-linked list.
+  // The list's head node is inlined in the iterator.
+  struct CleanupNode {
+    // True if the node is not used. Only head nodes might be unused.
+    bool IsEmpty() const { return function == nullptr; }
+    // Invokes the cleanup function.
+    void Run() {
+      assert(function != nullptr);
+      (*function)(arg1, arg2);
+    }
+
+    // The head node is used if the function pointer is not null.
     CleanupFunction function;
     void* arg1;
     void* arg2;
-    Cleanup* next;
+    CleanupNode* next;
   };
-  Cleanup cleanup_;
-
-  // No copying allowed
-  Iterator(const Iterator&);
-  void operator=(const Iterator&);
+  CleanupNode cleanup_head_;
 };
 
 // Return an empty iterator (yields nothing).
-extern Iterator* NewEmptyIterator();
+LEVELDB_EXPORT Iterator* NewEmptyIterator();
 
 // Return an empty iterator with the specified status.
-extern Iterator* NewErrorIterator(const Status& status);
+LEVELDB_EXPORT Iterator* NewErrorIterator(const Status& status);
 
 }  // namespace leveldb
 
diff --git a/src/leveldb/include/leveldb/options.h b/src/leveldb/include/leveldb/options.h
index 976e38122a..b7487726bc 100644
--- a/src/leveldb/include/leveldb/options.h
+++ b/src/leveldb/include/leveldb/options.h
@@ -7,6 +7,8 @@
 
 #include <stddef.h>
 
+#include "leveldb/export.h"
+
 namespace leveldb {
 
 class Cache;
@@ -23,12 +25,15 @@ class Snapshot;
 enum CompressionType {
   // NOTE: do not change the values of existing entries, as these are
   // part of the persistent format on disk.
-  kNoCompression     = 0x0,
+  kNoCompression = 0x0,
   kSnappyCompression = 0x1
 };
 
 // Options to control the behavior of a database (passed to DB::Open)
-struct Options {
+struct LEVELDB_EXPORT Options {
+  // Create an Options object with default values for all fields.
+  Options();
+
   // -------------------
   // Parameters that affect behavior
 
@@ -41,20 +46,17 @@ struct Options {
   const Comparator* comparator;
 
   // If true, the database will be created if it is missing.
-  // Default: false
-  bool create_if_missing;
+  bool create_if_missing = false;
 
   // If true, an error is raised if the database already exists.
-  // Default: false
-  bool error_if_exists;
+  bool error_if_exists = false;
 
   // If true, the implementation will do aggressive checking of the
   // data it is processing and will stop early if it detects any
   // errors.  This may have unforeseen ramifications: for example, a
   // corruption of one DB entry may cause a large number of entries to
   // become unreadable or for the entire DB to become unopenable.
-  // Default: false
-  bool paranoid_checks;
+  bool paranoid_checks = false;
 
   // Use the specified object to interact with the environment,
   // e.g. to read/write files, schedule background work, etc.
@@ -62,10 +64,9 @@ struct Options {
   Env* env;
 
   // Any internal progress/error information generated by the db will
-  // be written to info_log if it is non-NULL, or to a file stored
-  // in the same directory as the DB contents if info_log is NULL.
-  // Default: NULL
-  Logger* info_log;
+  // be written to info_log if it is non-null, or to a file stored
+  // in the same directory as the DB contents if info_log is null.
+  Logger* info_log = nullptr;
 
   // -------------------
   // Parameters that affect performance
@@ -78,39 +79,30 @@ struct Options {
   // so you may wish to adjust this parameter to control memory usage.
   // Also, a larger write buffer will result in a longer recovery time
   // the next time the database is opened.
-  //
-  // Default: 4MB
-  size_t write_buffer_size;
+  size_t write_buffer_size = 4 * 1024 * 1024;
 
   // Number of open files that can be used by the DB.  You may need to
   // increase this if your database has a large working set (budget
   // one open file per 2MB of working set).
-  //
-  // Default: 1000
-  int max_open_files;
+  int max_open_files = 1000;
 
   // Control over blocks (user data is stored in a set of blocks, and
   // a block is the unit of reading from disk).
 
-  // If non-NULL, use the specified cache for blocks.
-  // If NULL, leveldb will automatically create and use an 8MB internal cache.
-  // Default: NULL
-  Cache* block_cache;
+  // If non-null, use the specified cache for blocks.
+  // If null, leveldb will automatically create and use an 8MB internal cache.
+  Cache* block_cache = nullptr;
 
   // Approximate size of user data packed per block.  Note that the
   // block size specified here corresponds to uncompressed data.  The
   // actual size of the unit read from disk may be smaller if
   // compression is enabled.  This parameter can be changed dynamically.
-  //
-  // Default: 4K
-  size_t block_size;
+  size_t block_size = 4 * 1024;
 
   // Number of keys between restart points for delta encoding of keys.
   // This parameter can be changed dynamically.  Most clients should
   // leave this parameter alone.
-  //
-  // Default: 16
-  int block_restart_interval;
+  int block_restart_interval = 16;
 
   // Leveldb will write up to this amount of bytes to a file before
   // switching to a new one.
@@ -120,9 +112,7 @@ struct Options {
   // compactions and hence longer latency/performance hiccups.
   // Another reason to increase this parameter might be when you are
   // initially populating a large database.
-  //
-  // Default: 2MB
-  size_t max_file_size;
+  size_t max_file_size = 2 * 1024 * 1024;
 
   // Compress blocks using the specified compression algorithm.  This
   // parameter can be changed dynamically.
@@ -138,53 +128,43 @@ struct Options {
   // worth switching to kNoCompression.  Even if the input data is
   // incompressible, the kSnappyCompression implementation will
   // efficiently detect that and will switch to uncompressed mode.
-  CompressionType compression;
+  CompressionType compression = kSnappyCompression;
 
   // EXPERIMENTAL: If true, append to existing MANIFEST and log files
   // when a database is opened.  This can significantly speed up open.
   //
   // Default: currently false, but may become true later.
-  bool reuse_logs;
+  bool reuse_logs = false;
 
-  // If non-NULL, use the specified filter policy to reduce disk reads.
+  // If non-null, use the specified filter policy to reduce disk reads.
   // Many applications will benefit from passing the result of
   // NewBloomFilterPolicy() here.
-  //
-  // Default: NULL
-  const FilterPolicy* filter_policy;
-
-  // Create an Options object with default values for all fields.
-  Options();
+  const FilterPolicy* filter_policy = nullptr;
 };
 
 // Options that control read operations
-struct ReadOptions {
+struct LEVELDB_EXPORT ReadOptions {
+  ReadOptions() = default;
+
   // If true, all data read from underlying storage will be
   // verified against corresponding checksums.
-  // Default: false
-  bool verify_checksums;
+  bool verify_checksums = false;
 
   // Should the data read for this iteration be cached in memory?
   // Callers may wish to set this field to false for bulk scans.
-  // Default: true
-  bool fill_cache;
+  bool fill_cache = true;
 
-  // If "snapshot" is non-NULL, read as of the supplied snapshot
+  // If "snapshot" is non-null, read as of the supplied snapshot
   // (which must belong to the DB that is being read and which must
-  // not have been released).  If "snapshot" is NULL, use an implicit
+  // not have been released).  If "snapshot" is null, use an implicit
   // snapshot of the state at the beginning of this read operation.
-  // Default: NULL
-  const Snapshot* snapshot;
-
-  ReadOptions()
-      : verify_checksums(false),
-        fill_cache(true),
-        snapshot(NULL) {
-  }
+  const Snapshot* snapshot = nullptr;
 };
 
 // Options that control write operations
-struct WriteOptions {
+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
@@ -199,13 +179,7 @@ struct WriteOptions {
   // crash semantics as the "write()" system call.  A DB write
   // with sync==true has similar crash semantics to a "write()"
   // system call followed by "fsync()".
-  //
-  // Default: false
-  bool sync;
-
-  WriteOptions()
-      : sync(false) {
-  }
+  bool sync = false;
 };
 
 }  // namespace leveldb
diff --git a/src/leveldb/include/leveldb/slice.h b/src/leveldb/include/leveldb/slice.h
index bc367986f7..2df417dc31 100644
--- a/src/leveldb/include/leveldb/slice.h
+++ b/src/leveldb/include/leveldb/slice.h
@@ -18,23 +18,30 @@
 #include <assert.h>
 #include <stddef.h>
 #include <string.h>
+
 #include <string>
 
+#include "leveldb/export.h"
+
 namespace leveldb {
 
-class Slice {
+class LEVELDB_EXPORT Slice {
  public:
   // Create an empty slice.
-  Slice() : data_(""), size_(0) { }
+  Slice() : data_(""), size_(0) {}
 
   // Create a slice that refers to d[0,n-1].
-  Slice(const char* d, size_t n) : data_(d), size_(n) { }
+  Slice(const char* d, size_t n) : data_(d), size_(n) {}
 
   // Create a slice that refers to the contents of "s"
-  Slice(const std::string& s) : data_(s.data()), size_(s.size()) { }
+  Slice(const std::string& s) : data_(s.data()), size_(s.size()) {}
 
   // Create a slice that refers to s[0,strlen(s)-1]
-  Slice(const char* s) : data_(s), size_(strlen(s)) { }
+  Slice(const char* s) : data_(s), size_(strlen(s)) {}
+
+  // Intentionally copyable.
+  Slice(const Slice&) = default;
+  Slice& operator=(const Slice&) = default;
 
   // Return a pointer to the beginning of the referenced data
   const char* data() const { return data_; }
@@ -53,7 +60,10 @@ class Slice {
   }
 
   // Change this slice to refer to an empty array
-  void clear() { data_ = ""; size_ = 0; }
+  void clear() {
+    data_ = "";
+    size_ = 0;
+  }
 
   // Drop the first "n" bytes from this slice.
   void remove_prefix(size_t n) {
@@ -73,15 +83,12 @@ class Slice {
 
   // Return true iff "x" is a prefix of "*this"
   bool starts_with(const Slice& x) const {
-    return ((size_ >= x.size_) &&
-            (memcmp(data_, x.data_, x.size_) == 0));
+    return ((size_ >= x.size_) && (memcmp(data_, x.data_, x.size_) == 0));
   }
 
  private:
   const char* data_;
   size_t size_;
-
-  // Intentionally copyable
 };
 
 inline bool operator==(const Slice& x, const Slice& y) {
@@ -89,21 +96,20 @@ inline bool operator==(const Slice& x, const Slice& y) {
           (memcmp(x.data(), y.data(), x.size()) == 0));
 }
 
-inline bool operator!=(const Slice& x, const Slice& y) {
-  return !(x == y);
-}
+inline bool operator!=(const Slice& x, const Slice& y) { return !(x == y); }
 
 inline int Slice::compare(const Slice& b) const {
   const size_t min_len = (size_ < b.size_) ? size_ : b.size_;
   int r = memcmp(data_, b.data_, min_len);
   if (r == 0) {
-    if (size_ < b.size_) r = -1;
-    else if (size_ > b.size_) r = +1;
+    if (size_ < b.size_)
+      r = -1;
+    else if (size_ > b.size_)
+      r = +1;
   }
   return r;
 }
 
 }  // namespace leveldb
 
-
 #endif  // STORAGE_LEVELDB_INCLUDE_SLICE_H_
diff --git a/src/leveldb/include/leveldb/status.h b/src/leveldb/include/leveldb/status.h
index d9575f9753..e3273144e4 100644
--- a/src/leveldb/include/leveldb/status.h
+++ b/src/leveldb/include/leveldb/status.h
@@ -13,20 +13,25 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_STATUS_H_
 #define STORAGE_LEVELDB_INCLUDE_STATUS_H_
 
+#include <algorithm>
 #include <string>
+
+#include "leveldb/export.h"
 #include "leveldb/slice.h"
 
 namespace leveldb {
 
-class Status {
+class LEVELDB_EXPORT Status {
  public:
   // Create a success status.
-  Status() : state_(NULL) { }
+  Status() noexcept : state_(nullptr) {}
   ~Status() { delete[] state_; }
 
-  // Copy the specified status.
-  Status(const Status& s);
-  void operator=(const Status& s);
+  Status(const Status& rhs);
+  Status& operator=(const Status& rhs);
+
+  Status(Status&& rhs) noexcept : state_(rhs.state_) { rhs.state_ = nullptr; }
+  Status& operator=(Status&& rhs) noexcept;
 
   // Return a success status.
   static Status OK() { return Status(); }
@@ -49,7 +54,7 @@ class Status {
   }
 
   // Returns true iff the status indicates success.
-  bool ok() const { return (state_ == NULL); }
+  bool ok() const { return (state_ == nullptr); }
 
   // Returns true iff the status indicates a NotFound error.
   bool IsNotFound() const { return code() == kNotFound; }
@@ -71,13 +76,6 @@ class 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,
@@ -88,23 +86,35 @@ class Status {
   };
 
   Code code() const {
-    return (state_ == NULL) ? kOk : static_cast<Code>(state_[4]);
+    return (state_ == nullptr) ? kOk : static_cast<Code>(state_[4]);
   }
 
   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& s) {
-  state_ = (s.state_ == NULL) ? NULL : CopyState(s.state_);
+inline Status::Status(const Status& rhs) {
+  state_ = (rhs.state_ == nullptr) ? nullptr : CopyState(rhs.state_);
 }
-inline void Status::operator=(const Status& s) {
-  // The following condition catches both aliasing (when this == &s),
-  // and the common case where both s and *this are ok.
-  if (state_ != s.state_) {
+inline Status& Status::operator=(const Status& rhs) {
+  // The following condition catches both aliasing (when this == &rhs),
+  // and the common case where both rhs and *this are ok.
+  if (state_ != rhs.state_) {
     delete[] state_;
-    state_ = (s.state_ == NULL) ? NULL : CopyState(s.state_);
+    state_ = (rhs.state_ == nullptr) ? nullptr : CopyState(rhs.state_);
   }
+  return *this;
+}
+inline Status& Status::operator=(Status&& rhs) noexcept {
+  std::swap(state_, rhs.state_);
+  return *this;
 }
 
 }  // namespace leveldb
diff --git a/src/leveldb/include/leveldb/table.h b/src/leveldb/include/leveldb/table.h
index a9746c3f5e..25c6013116 100644
--- a/src/leveldb/include/leveldb/table.h
+++ b/src/leveldb/include/leveldb/table.h
@@ -6,6 +6,8 @@
 #define STORAGE_LEVELDB_INCLUDE_TABLE_H_
 
 #include <stdint.h>
+
+#include "leveldb/export.h"
 #include "leveldb/iterator.h"
 
 namespace leveldb {
@@ -21,7 +23,7 @@ class TableCache;
 // A Table is a sorted map from strings to strings.  Tables are
 // immutable and persistent.  A Table may be safely accessed from
 // multiple threads without external synchronization.
-class Table {
+class LEVELDB_EXPORT Table {
  public:
   // Attempt to open the table that is stored in bytes [0..file_size)
   // of "file", and read the metadata entries necessary to allow
@@ -30,15 +32,16 @@ class Table {
   // If successful, returns ok and sets "*table" to the newly opened
   // table.  The client should delete "*table" when no longer needed.
   // If there was an error while initializing the table, sets "*table"
-  // to NULL and returns a non-ok status.  Does not take ownership of
+  // to nullptr and returns a non-ok status.  Does not take ownership of
   // "*source", but the client must ensure that "source" remains live
   // for the duration of the returned table's lifetime.
   //
   // *file must remain live while this Table is in use.
-  static Status Open(const Options& options,
-                     RandomAccessFile* file,
-                     uint64_t file_size,
-                     Table** table);
+  static Status Open(const Options& options, RandomAccessFile* file,
+                     uint64_t file_size, Table** table);
+
+  Table(const Table&) = delete;
+  Table& operator=(const Table&) = delete;
 
   ~Table();
 
@@ -56,28 +59,24 @@ class 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));
-
+  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);
 
-  // No copying allowed
-  Table(const Table&);
-  void operator=(const Table&);
+  Rep* const rep_;
 };
 
 }  // namespace leveldb
diff --git a/src/leveldb/include/leveldb/table_builder.h b/src/leveldb/include/leveldb/table_builder.h
index 5fd1dc71f1..7d8896bb89 100644
--- a/src/leveldb/include/leveldb/table_builder.h
+++ b/src/leveldb/include/leveldb/table_builder.h
@@ -14,6 +14,8 @@
 #define STORAGE_LEVELDB_INCLUDE_TABLE_BUILDER_H_
 
 #include <stdint.h>
+
+#include "leveldb/export.h"
 #include "leveldb/options.h"
 #include "leveldb/status.h"
 
@@ -23,13 +25,16 @@ class BlockBuilder;
 class BlockHandle;
 class WritableFile;
 
-class TableBuilder {
+class LEVELDB_EXPORT TableBuilder {
  public:
   // Create a builder that will store the contents of the table it is
   // building in *file.  Does not close the file.  It is up to the
   // caller to close the file after calling Finish().
   TableBuilder(const Options& options, WritableFile* file);
 
+  TableBuilder(const TableBuilder&) = delete;
+  TableBuilder& operator=(const TableBuilder&) = delete;
+
   // REQUIRES: Either Finish() or Abandon() has been called.
   ~TableBuilder();
 
@@ -81,10 +86,6 @@ class TableBuilder {
 
   struct Rep;
   Rep* rep_;
-
-  // No copying allowed
-  TableBuilder(const TableBuilder&);
-  void operator=(const TableBuilder&);
 };
 
 }  // namespace leveldb
diff --git a/src/leveldb/include/leveldb/write_batch.h b/src/leveldb/include/leveldb/write_batch.h
index ee9aab68e0..94d4115fed 100644
--- a/src/leveldb/include/leveldb/write_batch.h
+++ b/src/leveldb/include/leveldb/write_batch.h
@@ -22,15 +22,29 @@
 #define STORAGE_LEVELDB_INCLUDE_WRITE_BATCH_H_
 
 #include <string>
+
+#include "leveldb/export.h"
 #include "leveldb/status.h"
 
 namespace leveldb {
 
 class Slice;
 
-class WriteBatch {
+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.
+  WriteBatch(const WriteBatch&) = default;
+  WriteBatch& operator=(const WriteBatch&) = default;
+
   ~WriteBatch();
 
   // Store the mapping "key->value" in the database.
@@ -42,21 +56,26 @@ class WriteBatch {
   // Clear all updates buffered in this batch.
   void Clear();
 
+  // The size of the database changes caused by this batch.
+  //
+  // This number is tied to implementation details, and may change across
+  // releases. It is intended for LevelDB usage metrics.
+  size_t ApproximateSize() const;
+
+  // Copies the operations in "source" to this batch.
+  //
+  // This runs in O(source size) time. However, the constant factor is better
+  // than calling Iterate() over the source batch with a Handler that replicates
+  // the operations into this batch.
+  void Append(const WriteBatch& source);
+
   // Support for iterating over the contents of a batch.
-  class 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:
   friend class WriteBatchInternal;
 
   std::string rep_;  // See comment in write_batch.cc for the format of rep_
-
-  // Intentionally copyable
 };
 
 }  // namespace leveldb