Windows JNI, refactor: move OpenDirectory to JNI

Move the OpenDirectory helper method into the JNI
library. We'll need it there; a subsequent change
will make use of it there.

See https://github.com/bazelbuild/bazel/issues/2107

--
PiperOrigin-RevId: 147448792
MOS_MIGRATED_REVID=147448792

3 files changed, 28 insertions, 3 deletions

diff --git a/src/main/native/BUILD b/src/main/native/BUILD
index ba605707c1..653b595ad2 100644
--- a/src/main/native/BUILD
+++ b/src/main/native/BUILD
@@ -64,8 +64,14 @@ cc_binary(
 
 cc_library(
     name = "windows_jni_lib",
-    srcs = ["windows_util.cc"],
-    hdrs = ["windows_util.h"],
+    srcs = [
+        "windows_file_operations.cc",
+        "windows_util.cc",
+    ],
+    hdrs = [
+        "windows_file_operations.h",
+        "windows_util.h",
+    ],
     visibility = [
         "//src/main/cpp:__subpackages__",
         "//src/test/cpp:__subpackages__",
diff --git a/src/main/native/windows_file_operations.cc b/src/main/native/windows_file_operations.cc
index e9e561eeb8..b5780b2c86 100644
--- a/src/main/native/windows_file_operations.cc
+++ b/src/main/native/windows_file_operations.cc
@@ -47,4 +47,17 @@ bool GetLongPath(const WCHAR* path, unique_ptr<WCHAR[]>* result) {
   return true;
 }
 
+HANDLE OpenDirectory(const WCHAR* path, bool read_write) {
+  return ::CreateFileW(
+      /* lpFileName */ path,
+      /* dwDesiredAccess */
+      read_write ? (GENERIC_READ | GENERIC_WRITE) : GENERIC_READ,
+      /* dwShareMode */ 0,
+      /* lpSecurityAttributes */ NULL,
+      /* dwCreationDisposition */ OPEN_EXISTING,
+      /* dwFlagsAndAttributes */ FILE_FLAG_OPEN_REPARSE_POINT |
+          FILE_FLAG_BACKUP_SEMANTICS,
+      /* hTemplateFile */ NULL);
+}
+
 }  // namespace windows_util
diff --git a/src/main/native/windows_file_operations.h b/src/main/native/windows_file_operations.h
index e28200f359..ded07b0a1f 100644
--- a/src/main/native/windows_file_operations.h
+++ b/src/main/native/windows_file_operations.h
@@ -50,11 +50,17 @@ int IsJunctionOrDirectorySymlink(const WCHAR* path);
 // Computes the long version of `path` if it has any 8dot3 style components.
 // Returns true upon success and sets `result` to point to the buffer.
 // `path` must be an absolute, normalized, Windows style path, with a "\\?\"
-// prefix if its longer than MAX_PATH. The result will have a "\\?\" prefix if
+// prefix if it's longer than MAX_PATH. The result will have a "\\?\" prefix if
 // and only if `path` had one as well. (It's the caller's responsibility to keep
 // or remove this prefix.)
 bool GetLongPath(const WCHAR* path, unique_ptr<WCHAR[]>* result);
 
+// Opens a directory using CreateFileW.
+// `path` must be a valid Windows path, with "\\?\" prefix if it's long.
+// If `read_write` is true then the directory is opened for reading and writing,
+// otherwise only for reading.
+HANDLE OpenDirectory(const WCHAR* path, bool read_write);
+
 }  // namespace windows_util
 
 #endif  // BAZEL_SRC_MAIN_NATIVE_WINDOWS_FILE_OPERATIONS_H_