8 files changed, 69 insertions, 48 deletions
diff --git a/include/leveldb/c.h b/include/leveldb/c.h
index 02c79ba..62e1f64 100644
--- a/include/leveldb/c.h
+++ b/include/leveldb/c.h
@@ -40,16 +40,16 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_C_H_
 #define STORAGE_LEVELDB_INCLUDE_C_H_
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdint.h>
 
 #include "leveldb/export.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Exported types */
 
 typedef struct leveldb_t leveldb_t;
diff --git a/include/leveldb/cache.h b/include/leveldb/cache.h
index 7d1a221..a94c683 100644
--- a/include/leveldb/cache.h
+++ b/include/leveldb/cache.h
@@ -18,7 +18,7 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_CACHE_H_
 #define STORAGE_LEVELDB_INCLUDE_CACHE_H_
 
-#include <stdint.h>
+#include <cstdint>
 
 #include "leveldb/export.h"
 #include "leveldb/slice.h"
@@ -96,14 +96,6 @@ class LEVELDB_EXPORT Cache {
   // Return an estimate of the combined charges of all elements stored in the
   // cache.
   virtual size_t TotalCharge() const = 0;
-
- private:
-  void LRU_Remove(Handle* e);
-  void LRU_Append(Handle* e);
-  void Unref(Handle* e);
-
-  struct Rep;
-  Rep* rep_;
 };
 
 }  // namespace leveldb
diff --git a/include/leveldb/db.h b/include/leveldb/db.h
index b73014a..a13d147 100644
--- a/include/leveldb/db.h
+++ b/include/leveldb/db.h
@@ -5,8 +5,8 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_DB_H_
 #define STORAGE_LEVELDB_INCLUDE_DB_H_
 
-#include <stdint.h>
-#include <stdio.h>
+#include <cstdint>
+#include <cstdio>
 
 #include "leveldb/export.h"
 #include "leveldb/iterator.h"
@@ -16,7 +16,7 @@ namespace leveldb {
 
 // Update CMakeLists.txt if you change these
 static const int kMajorVersion = 1;
-static const int kMinorVersion = 22;
+static const int kMinorVersion = 23;
 
 struct Options;
 struct ReadOptions;
diff --git a/include/leveldb/env.h b/include/leveldb/env.h
index 112fe96..e00895a 100644
--- a/include/leveldb/env.h
+++ b/include/leveldb/env.h
@@ -13,30 +13,26 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_ENV_H_
 #define STORAGE_LEVELDB_INCLUDE_ENV_H_
 
-#include <stdarg.h>
-#include <stdint.h>
-
+#include <cstdarg>
+#include <cstdint>
 #include <string>
 #include <vector>
 
 #include "leveldb/export.h"
 #include "leveldb/status.h"
 
+// This workaround can be removed when leveldb::Env::DeleteFile is removed.
 #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.
+// On Windows, the method name DeleteFile (below) introduces the risk of
+// triggering undefined behavior by exposing the compiler to different
+// declarations of the Env class in different translation units.
 //
-// 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.
+// This is because <windows.h>, a fairly popular header file for Windows
+// applications, defines a DeleteFile macro. So, files that include the Windows
+// header before this header will contain an altered Env declaration.
 //
-// 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.
+// This workaround ensures that the compiler sees the same Env declaration,
+// independently of whether <windows.h> was included.
 #if defined(DeleteFile)
 #undef DeleteFile
 #define LEVELDB_DELETEFILE_UNDEFINED
@@ -54,7 +50,7 @@ class WritableFile;
 
 class LEVELDB_EXPORT Env {
  public:
-  Env() = default;
+  Env();
 
   Env(const Env&) = delete;
   Env& operator=(const Env&) = delete;
@@ -122,15 +118,48 @@ class LEVELDB_EXPORT Env {
   // Original contents of *results are dropped.
   virtual Status GetChildren(const std::string& dir,
                              std::vector<std::string>* result) = 0;
-
   // Delete the named file.
-  virtual Status DeleteFile(const std::string& fname) = 0;
+  //
+  // The default implementation calls DeleteFile, to support legacy Env
+  // implementations. Updated Env implementations must override RemoveFile and
+  // ignore the existence of DeleteFile. Updated code calling into the Env API
+  // must call RemoveFile instead of DeleteFile.
+  //
+  // A future release will remove DeleteDir and the default implementation of
+  // RemoveDir.
+  virtual Status RemoveFile(const std::string& fname);
+
+  // DEPRECATED: Modern Env implementations should override RemoveFile instead.
+  //
+  // The default implementation calls RemoveFile, to support legacy Env user
+  // code that calls this method on modern Env implementations. Modern Env user
+  // code should call RemoveFile.
+  //
+  // A future release will remove this method.
+  virtual Status DeleteFile(const std::string& fname);
 
   // Create the specified directory.
   virtual Status CreateDir(const std::string& dirname) = 0;
 
   // Delete the specified directory.
-  virtual Status DeleteDir(const std::string& dirname) = 0;
+  //
+  // The default implementation calls DeleteDir, to support legacy Env
+  // implementations. Updated Env implementations must override RemoveDir and
+  // ignore the existence of DeleteDir. Modern code calling into the Env API
+  // must call RemoveDir instead of DeleteDir.
+  //
+  // A future release will remove DeleteDir and the default implementation of
+  // RemoveDir.
+  virtual Status RemoveDir(const std::string& dirname);
+
+  // DEPRECATED: Modern Env implementations should override RemoveDir instead.
+  //
+  // The default implementation calls RemoveDir, to support legacy Env user
+  // code that calls this method on modern Env implementations. Modern Env user
+  // code should call RemoveDir.
+  //
+  // A future release will remove this method.
+  virtual Status DeleteDir(const std::string& dirname);
 
   // Store the size of fname in *file_size.
   virtual Status GetFileSize(const std::string& fname, uint64_t* file_size) = 0;
@@ -271,7 +300,7 @@ class LEVELDB_EXPORT Logger {
   virtual ~Logger();
 
   // Write an entry to the log file with the specified format.
-  virtual void Logv(const char* format, va_list ap) = 0;
+  virtual void Logv(const char* format, std::va_list ap) = 0;
 };
 
 // Identifies a locked file.
@@ -333,14 +362,14 @@ class LEVELDB_EXPORT EnvWrapper : public Env {
                      std::vector<std::string>* r) override {
     return target_->GetChildren(dir, r);
   }
-  Status DeleteFile(const std::string& f) override {
-    return target_->DeleteFile(f);
+  Status RemoveFile(const std::string& f) override {
+    return target_->RemoveFile(f);
   }
   Status CreateDir(const std::string& d) override {
     return target_->CreateDir(d);
   }
-  Status DeleteDir(const std::string& d) override {
-    return target_->DeleteDir(d);
+  Status RemoveDir(const std::string& d) override {
+    return target_->RemoveDir(d);
   }
   Status GetFileSize(const std::string& f, uint64_t* s) override {
     return target_->GetFileSize(f, s);
@@ -375,7 +404,8 @@ class LEVELDB_EXPORT EnvWrapper : public Env {
 
 }  // namespace leveldb
 
-// Redefine DeleteFile if necessary.
+// This workaround can be removed when leveldb::Env::DeleteFile is removed.
+// Redefine DeleteFile if it was undefined earlier.
 #if defined(_WIN32) && defined(LEVELDB_DELETEFILE_UNDEFINED)
 #if defined(UNICODE)
 #define DeleteFile DeleteFileW
diff --git a/include/leveldb/options.h b/include/leveldb/options.h
index b748772..0f285bc 100644
--- a/include/leveldb/options.h
+++ b/include/leveldb/options.h
@@ -5,7 +5,7 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_OPTIONS_H_
 #define STORAGE_LEVELDB_INCLUDE_OPTIONS_H_
 
-#include <stddef.h>
+#include <cstddef>
 
 #include "leveldb/export.h"
 
diff --git a/include/leveldb/slice.h b/include/leveldb/slice.h
index 2df417d..37cb821 100644
--- a/include/leveldb/slice.h
+++ b/include/leveldb/slice.h
@@ -15,10 +15,9 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_SLICE_H_
 #define STORAGE_LEVELDB_INCLUDE_SLICE_H_
 
-#include <assert.h>
-#include <stddef.h>
-#include <string.h>
-
+#include <cassert>
+#include <cstddef>
+#include <cstring>
 #include <string>
 
 #include "leveldb/export.h"
diff --git a/include/leveldb/table.h b/include/leveldb/table.h
index 25c6013..a30e903 100644
--- a/include/leveldb/table.h
+++ b/include/leveldb/table.h
@@ -5,7 +5,7 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_TABLE_H_
 #define STORAGE_LEVELDB_INCLUDE_TABLE_H_
 
-#include <stdint.h>
+#include <cstdint>
 
 #include "leveldb/export.h"
 #include "leveldb/iterator.h"
diff --git a/include/leveldb/table_builder.h b/include/leveldb/table_builder.h
index 7d8896b..85710c3 100644
--- a/include/leveldb/table_builder.h
+++ b/include/leveldb/table_builder.h
@@ -13,7 +13,7 @@
 #ifndef STORAGE_LEVELDB_INCLUDE_TABLE_BUILDER_H_
 #define STORAGE_LEVELDB_INCLUDE_TABLE_BUILDER_H_
 
-#include <stdint.h>
+#include <cstdint>
 
 #include "leveldb/export.h"
 #include "leveldb/options.h"