chore: import upstream snapshot with attribution

tensorflow/c/experimental/filesystem/plugins/windows/BUILD

@@ -0,0 +1,35 @@
+# Experimental windows filesystem plugin.
+load("//tensorflow:tensorflow.bzl", "get_win_copts", "tf_cc_shared_object")
+load("//tensorflow/core/platform:rules_cc.bzl", "cc_library")
+
+package(
+    # copybara:uncomment default_applicable_licenses = ["//tensorflow:license"],
+    licenses = ["notice"],
+)
+
+# Filesystem implementation for Windows environment
+tf_cc_shared_object(
+    name = "windows_filesystem.dll",
+    framework_so = [],
+    linkstatic = False,
+    tags = [
+        "manual",
+        "nobuilder",
+        "notap",
+    ],
+    visibility = ["//visibility:public"],
+    deps = [":windows_filesystem_impl"],
+)
+
+# The real implementation of the filesystem.
+cc_library(
+    name = "windows_filesystem_impl",
+    srcs = ["windows_filesystem.cc"],
+    copts = get_win_copts(),
+    tags = [
+        "manual",
+        "nobuilder",
+        "notap",
+    ],
+    deps = ["//tensorflow/c/experimental/filesystem:filesystem_interface"],
+)

tensorflow/c/experimental/filesystem/plugins/windows/windows_filesystem.cc

@@ -0,0 +1,72 @@
+/* Copyright 2020 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+#include <stdlib.h>
+#include <string.h>
+
+#include "tensorflow/c/experimental/filesystem/filesystem_interface.h"
+
+// Implementation of a filesystem for POSIX environments.
+// This filesystem will support `file://` and empty (local) URI schemes.
+
+static void* plugin_memory_allocate(size_t size) { return calloc(1, size); }
+static void plugin_memory_free(void* ptr) { free(ptr); }
+
+// SECTION 1. Implementation for `TF_RandomAccessFile`
+// ----------------------------------------------------------------------------
+namespace tf_random_access_file {
+
+// TODO(b/139060984): Implement later
+
+}  // namespace tf_random_access_file
+
+// SECTION 2. Implementation for `TF_WritableFile`
+// ----------------------------------------------------------------------------
+namespace tf_writable_file {
+
+// TODO(b/139060984): Implement later
+
+}  // namespace tf_writable_file
+
+// SECTION 3. Implementation for `TF_ReadOnlyMemoryRegion`
+// ----------------------------------------------------------------------------
+namespace tf_read_only_memory_region {
+
+// TODO(b/139060984): Implement later
+
+}  // namespace tf_read_only_memory_region
+
+// SECTION 4. Implementation for `TF_Filesystem`, the actual filesystem
+// ----------------------------------------------------------------------------
+namespace tf_windows_filesystem {
+
+// TODO(b/139060984): Implement later
+
+}  // namespace tf_windows_filesystem
+
+static void ProvideFilesystemSupportFor(TF_FilesystemPluginOps* ops,
+                                        const char* uri) {
+  TF_SetFilesystemVersionMetadata(ops);
+  ops->scheme = strdup(uri);
+}
+
+void TF_InitPlugin(TF_FilesystemPluginInfo* info) {
+  info->plugin_memory_allocate = plugin_memory_allocate;
+  info->plugin_memory_free = plugin_memory_free;
+  info->num_schemes = 2;
+  info->ops = static_cast<TF_FilesystemPluginOps*>(
+      plugin_memory_allocate(info->num_schemes * sizeof(info->ops[0])));
+  ProvideFilesystemSupportFor(&info->ops[0], "");
+  ProvideFilesystemSupportFor(&info->ops[1], "file");
+}