Releasing the former Stadia file transfer tools

The tools allow efficient and fast synchronization of large directory
trees from a Windows workstation to a Linux target machine.

cdc_rsync* support efficient copy of files by using content-defined
chunking (CDC) to identify chunks within files that can be reused.

asset_stream_manager + cdc_fuse_fs support efficient streaming of a
local directory to a remote virtual file system based on FUSE. It also
employs CDC to identify and reuse unchanged data chunks.

asset_stream_manager/testing_asset_stream_server.h

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * 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.
+ */
+
+#ifndef ASSET_STREAM_MANAGER_TESTING_ASSET_STREAM_SERVER_H_
+#define ASSET_STREAM_MANAGER_TESTING_ASSET_STREAM_SERVER_H_
+
+#include <memory>
+#include <string>
+
+#include "absl/base/thread_annotations.h"
+#include "absl/status/status.h"
+#include "absl/synchronization/mutex.h"
+#include "asset_stream_manager/grpc_asset_stream_server.h"
+#include "manifest/manifest_proto_defs.h"
+
+namespace cdc_ft {
+
+// Not thread-safe testing server for streaming assets.
+class TestingAssetStreamServer : public AssetStreamServer {
+ public:
+  TestingAssetStreamServer(std::string src_dir,
+                           DataStoreReader* data_store_reader,
+                           FileChunkMap* file_chunks);
+
+  ~TestingAssetStreamServer();
+
+  // AssetStreamServer:
+
+  absl::Status Start(int port) override;
+
+  void SetManifestId(const ContentIdProto& manifest_id)
+      ABSL_LOCKS_EXCLUDED(mutex_) override;
+
+  absl::Status WaitForManifestAck(const std::string& instance,
+                                  absl::Duration timeout) override;
+  void Shutdown() override;
+
+  ContentIdProto GetManifestId() const ABSL_LOCKS_EXCLUDED(mutex_) override;
+
+ private:
+  mutable absl::Mutex mutex_;
+  ContentIdProto manifest_id_ ABSL_GUARDED_BY(mutex_);
+};
+
+}  // namespace cdc_ft
+
+#endif  // ASSET_STREAM_MANAGER_TESTING_ASSET_STREAM_SERVER_H_