Use parameter packs with io::JoinPath to allow passing more arguments.

Change: 132929686

tensorflow/contrib/session_bundle/session_bundle.cc

@@ -70,8 +70,8 @@ void AddAssetsTensorsToInputs(const StringPiece export_dir,
     return;
   }
   for (auto& asset : asset_files) {
-    Tensor assets_file_tensor = CreateStringTensor(io::JoinPath(
-        io::JoinPath(export_dir, kAssetsDirectory), asset.filename()));
+    Tensor assets_file_tensor = CreateStringTensor(
+        io::JoinPath(export_dir, kAssetsDirectory, asset.filename()));
     inputs->push_back(
         {asset.tensor_binding().tensor_name(), assets_file_tensor});
     }

tensorflow/core/lib/io/path.cc

@@ -18,11 +18,11 @@ limitations under the License.
 
 namespace tensorflow {
 namespace io {
+namespace internal {
 
-string JoinPath(StringPiece part1, StringPiece part2) {
+string JoinPathImpl(std::initializer_list<StringPiece> paths) {
   string result;
 
-  StringPiece paths[2] = {part1, part2};
   for (StringPiece path : paths) {
     if (path.empty()) continue;
 
@@ -49,8 +49,6 @@ string JoinPath(StringPiece part1, StringPiece part2) {
   return result;
 }
 
-namespace internal {
-
 // Return the parts of the path, split on the final "/".  If there is no
 // "/" in the path, the first part of the output is empty and the second
 // is the input. If the only "/" in the path is the first character, it is

tensorflow/core/lib/io/path.h

@@ -22,9 +22,13 @@ limitations under the License.
 namespace tensorflow {
 class StringPiece;
 namespace io {
+namespace internal {
+string JoinPathImpl(std::initializer_list<StringPiece> paths);
+}
 
 // Utility routines for processing filenames
 
+#ifndef SWIG  // variadic templates
 // Join multiple paths together, without introducing unnecessary path
 // separators.
 // For example:
@@ -38,7 +42,12 @@ namespace io {
 // Usage:
 // string path = io::JoinPath("/mydir", filename);
 // string path = io::JoinPath(FLAGS_test_srcdir, filename);
-string JoinPath(StringPiece part1, StringPiece part2);
+// string path = io::JoinPath("/full", "path", "to", "filename);
+template <typename... T>
+string JoinPath(const T&... args) {
+  return internal::JoinPathImpl({args...});
+}
+#endif /* SWIG */
 
 // Return true if path is absolute.
 bool IsAbsolutePath(StringPiece path);

tensorflow/core/lib/io/path_test.cc

@@ -31,6 +31,7 @@ TEST(PathTest, JoinPath) {
 
   EXPECT_EQ("/foo/bar/baz/blah/blink/biz",
             JoinPath("/foo/bar/baz/", "/blah/blink/biz"));
+  EXPECT_EQ("/foo/bar/baz/blah", JoinPath("/foo", "bar", "baz", "blah"));
 }
 
 TEST(PathTest, IsAbsolutePath) {