Added native support for Windows.

This change adds a native Windows port (port_windows.h) and a
Windows Env (WindowsEnv).

Note1: "small" is defined when including <Windows.h> so some
parameters were renamed to avoid conflict.

Note2: leveldb::Env defines the method: "DeleteFile" which is
also a constant defined when including <Windows.h>. The solution
was to ensure this macro is defined in env.h which forces
the function, when compiled, to be either DeleteFileA or
DeleteFileW when building for MBCS or UNICODE respectively.

This resolves #519 on GitHub.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=236364778

1 files changed, 25 insertions, 6 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f6a7c0a..1eaf48e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,6 +15,14 @@ set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
+if (WIN32)
+  set(LEVELDB_PLATFORM_NAME LEVELDB_PLATFORM_WINDOWS)
+  # TODO(cmumford): Make UNICODE configurable for Windows.
+  add_definitions(-D_UNICODE -DUNICODE)
+else (WIN32)
+  set(LEVELDB_PLATFORM_NAME LEVELDB_PLATFORM_POSIX)
+endif (WIN32)
+
 option(LEVELDB_BUILD_TESTS "Build LevelDB's unit tests" ON)
 option(LEVELDB_BUILD_BENCHMARKS "Build LevelDB's benchmarks" ON)
 option(LEVELDB_INSTALL "Install LevelDB's header and library" ON)
@@ -179,12 +187,19 @@ target_sources(leveldb
     "${LEVELDB_PUBLIC_INCLUDE_DIR}/write_batch.h"
 )
 
-# POSIX code is specified separately so we can leave it out in the future.
+if (WIN32)
+target_sources(leveldb
+  PRIVATE
+    "${PROJECT_SOURCE_DIR}/util/env_windows.cc"
+    "${PROJECT_SOURCE_DIR}/util/windows_logger.h"
+)
+else (WIN32)
 target_sources(leveldb
   PRIVATE
     "${PROJECT_SOURCE_DIR}/util/env_posix.cc"
     "${PROJECT_SOURCE_DIR}/util/posix_logger.h"
 )
+endif (WIN32)
 
 # MemEnv is not part of the interface and could be pulled to a separate library.
 target_sources(leveldb
@@ -203,7 +218,7 @@ target_compile_definitions(leveldb
     # Used by include/export.h when building shared libraries.
     LEVELDB_COMPILE_LIBRARY
     # Used by port/port.h.
-    LEVELDB_PLATFORM_POSIX=1
+    ${LEVELDB_PLATFORM_NAME}=1
 )
 if (NOT HAVE_CXX17_HAS_INCLUDE)
   target_compile_definitions(leveldb
@@ -265,7 +280,7 @@ if(LEVELDB_BUILD_TESTS)
     target_link_libraries("${test_target_name}" leveldb)
     target_compile_definitions("${test_target_name}"
       PRIVATE
-        LEVELDB_PLATFORM_POSIX=1
+        ${LEVELDB_PLATFORM_NAME}=1
     )
     if (NOT HAVE_CXX17_HAS_INCLUDE)
       target_compile_definitions("${test_target_name}"
@@ -314,8 +329,12 @@ if(LEVELDB_BUILD_TESTS)
     leveldb_test("${PROJECT_SOURCE_DIR}/util/logging_test.cc")
 
     # TODO(costan): This test also uses
-    #               "${PROJECT_SOURCE_DIR}/util/env_posix_test_helper.h"
-    leveldb_test("${PROJECT_SOURCE_DIR}/util/env_posix_test.cc")
+    #               "${PROJECT_SOURCE_DIR}/util/env_{posix|windows}_test_helper.h"
+    if (WIN32)
+      leveldb_test("${PROJECT_SOURCE_DIR}/util/env_windows_test.cc")
+    else (WIN32)
+      leveldb_test("${PROJECT_SOURCE_DIR}/util/env_posix_test.cc")
+    endif (WIN32)
   endif(NOT BUILD_SHARED_LIBS)
 endif(LEVELDB_BUILD_TESTS)
 
@@ -339,7 +358,7 @@ if(LEVELDB_BUILD_BENCHMARKS)
     target_link_libraries("${bench_target_name}" leveldb)
     target_compile_definitions("${bench_target_name}"
       PRIVATE
-        LEVELDB_PLATFORM_POSIX=1
+        ${LEVELDB_PLATFORM_NAME}=1
     )
     if (NOT HAVE_CXX17_HAS_INCLUDE)
       target_compile_definitions("${bench_target_name}"