Files
netris-cdc-file-transfer/data_store/mem_data_store.h
Christian Schneider 4326e972ac 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.
2022-11-03 10:39:10 +01:00

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2.7 KiB
C++

/*
* 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 DATA_STORE_MEM_DATA_STORE_H_
#define DATA_STORE_MEM_DATA_STORE_H_
#include <string>
#include <vector>
#include "data_store/data_store_writer.h"
#include "manifest/content_id.h"
namespace cdc_ft {
// In-memory implementation of a DataStoreWriter. Data needs to be pre-
// populated manually using AddData() and AddProto(). Useful for testing.
class MemDataStore : public DataStoreWriter {
public:
using ChunkMap = std::unordered_map<ContentIdProto, std::vector<char>>;
MemDataStore();
MemDataStore(const MemDataStore&) = delete;
MemDataStore& operator=(const MemDataStore&) = delete;
virtual ~MemDataStore();
// TODO: Extract AddData in a helper function.
// Adds |data| to the memory-backed storage and returns the id to it.
ContentIdProto AddData(std::vector<char> data);
// TODO: Extract AddProto in a helper function.
// Serializes |message|, adds it to the memory-backed storage, and returns the
// id to it.
ContentIdProto AddProto(const google::protobuf::MessageLite& message);
// Note: DO NOT MIX Add* get Get* methods in a multi-threaded environment!
// Get* methods are thread-safe as they are read-only, but Add* methods write
// to the data. They are not thread-safe.
// DataStoreReader:
absl::StatusOr<size_t> Get(const ContentIdProto& id, void* data,
size_t offset, size_t size) override;
absl::Status Get(const ContentIdProto& content_id, Buffer* data) override;
absl::Status Get(ChunkTransferList* chunks) override;
// DataStoreWriter:
bool Contains(const ContentIdProto& content_id) override;
absl::Status Put(const ContentIdProto& content_id, const void* data,
size_t size) override;
absl::Status Remove(const ContentIdProto& content_id) override;
absl::Status Wipe() override;
absl::Status Prune(std::unordered_set<ContentIdProto> ids_to_keep) override;
// Direct access to the chunks for testing.
const ChunkMap& Chunks() const { return data_lookup_; }
ChunkMap& Chunks() { return data_lookup_; }
private:
// Maps content IDs to chunks.
ChunkMap data_lookup_;
};
} // namespace cdc_ft
#endif // DATA_STORE_MEM_DATA_STORE_H_