Rename asset_stream_manager to cdc_stream (#27)

Fixes #13

cdc_stream/asset_stream_server.h

@@ -0,0 +1,97 @@
+/*
+ * 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 CDC_STREAM_ASSET_STREAM_SERVER_H_
+#define CDC_STREAM_ASSET_STREAM_SERVER_H_
+
+#include <memory>
+#include <string>
+
+#include "absl/status/status.h"
+#include "absl/time/time.h"
+#include "manifest/manifest_proto_defs.h"
+
+namespace cdc_ft {
+
+// Handles an event when content is transmitted from the workstation to a
+// gamelet.
+// |byte_count| number of bytes transferred during the session so far.
+// |chunk_count| number of chunks transferred during the session so far.
+// |instance_id| instance id, which identifies the session.
+using ContentSentHandler = std::function<void(
+    size_t byte_count, size_t chunk_count, std::string instance_id)>;
+
+// Handles requests to prioritize the given list of assets while updating the
+// manifest. |rel_paths| relative Unix paths of assets to prioritize.
+using PrioritizeAssetsHandler =
+    std::function<void(std::vector<std::string> rel_paths)>;
+
+class DataStoreReader;
+class FileChunkMap;
+
+enum class AssetStreamServerType { kGrpc, kTest };
+
+class AssetStreamServer {
+ public:
+  // Returns AssetStreamServer of |type|.
+  // |src_dir| is the directory on the workstation to mount.
+  // |data_store_reader| is responsible for loading content by ID.
+  // |file_chunks| is used for mapping data chunk ids to file locations.
+  // |content_sent| handles event when data is transferred from the workstation
+  // to a gamelet.
+  static std::unique_ptr<AssetStreamServer> Create(
+      AssetStreamServerType type, std::string src_dir,
+      DataStoreReader* data_store_reader, FileChunkMap* file_chunks,
+      ContentSentHandler content_sent, PrioritizeAssetsHandler prio_assets);
+
+  AssetStreamServer(const AssetStreamServer& other) = delete;
+  AssetStreamServer& operator=(const AssetStreamServer& other) = delete;
+  virtual ~AssetStreamServer() = default;
+
+  // Starts the asset stream server on the given |port|.
+  // Asserts that the server is not yet running.
+  virtual absl::Status Start(int port) = 0;
+
+  // Sets |manifest_id| to be distributed to gamelets.
+  // Thread-safe.
+  virtual void SetManifestId(const ContentIdProto& manifest_id) = 0;
+
+  // Waits until the FUSE for the given |instance| id has acknowledged the
+  // reception of the currently set manifest id. Returns a DeadlineExceeded
+  // error if the ack is not received within the given |timeout|.
+  // Thread-safe.
+  virtual absl::Status WaitForManifestAck(const std::string& instance,
+                                          absl::Duration timeout) = 0;
+
+  // Stops internal services and waits for the server to shut down.
+  virtual void Shutdown() = 0;
+
+  // Returns the used manifest id.
+  // Thread-safe.
+  virtual ContentIdProto GetManifestId() const = 0;
+
+ protected:
+  // Creates a new asset streaming server.
+  // |src_dir| is the directory on the workstation to mount.
+  // |data_store_reader| is responsible for loading content by ID.
+  // |file_chunks| is used for mapping data chunk ids to file locations.
+  AssetStreamServer(std::string src_dir, DataStoreReader* data_store_reader,
+                    FileChunkMap* file_chunks);
+};
+
+}  // namespace cdc_ft
+
+#endif  // CDC_STREAM_ASSET_STREAM_SERVER_H_