libcore/include/sirikata/core/transfer/TransferHandlers.hpp

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/*  Sirikata Transfer -- Content Transfer management system
 *  TransferHandlers.hpp
 *
 *  Copyright (c) 2010, Jeff Terrace
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are
 *  met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  * Neither the name of Sirikata nor the names of its contributors may
 *    be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/*  Created on: Jun 18th, 2010 */

#ifndef SIRIKATA_TransferHandlers_HPP__
#define SIRIKATA_TransferHandlers_HPP__

#include <sirikata/core/transfer/RemoteFileMetadata.hpp>
#include <sirikata/core/transfer/TransferData.hpp>
#include <sirikata/core/transfer/DiskCacheLayer.hpp>
#include <sirikata/core/transfer/MemoryCacheLayer.hpp>
#include <sirikata/core/transfer/LRUPolicy.hpp>
#include <sirikata/core/transfer/TransferRequest.hpp>

namespace Sirikata {
namespace Transfer {

//Forward declaration
class MetadataRequest;

/*
 * Base class for an implementation that satisfies name lookups
 * The input is a MetadataRequest and output is RemoteFileMetadata
 */
class NameHandler {

public:
    typedef std::tr1::function<void(
                std::tr1::shared_ptr<RemoteFileMetadata> response
            )> NameCallback;

    virtual void resolve(std::tr1::shared_ptr<MetadataRequest> request, NameCallback callback) = 0;

    virtual ~NameHandler() {
    }

};

/*
 * Base class for an implementation that satisfies chunk downloads
 * The input is a RemoteFileMetadata and a Chunk, output is DenseData
 */
class ChunkHandler {

public:
    typedef std::tr1::function<void(
                std::tr1::shared_ptr<const DenseData> response
            )> ChunkCallback;

    virtual void get(std::tr1::shared_ptr<RemoteFileMetadata> file,
            std::tr1::shared_ptr<Chunk> chunk, ChunkCallback callback) = 0;

    virtual ~ChunkHandler() {
    }

};


/*
 * Base class for an implementation that satisfies file uploads.
 * Input is credentials, files, requested path, and parameters, output is the path
 */
class UploadHandler {

public:
    typedef std::tr1::function<void(Transfer::URI)> UploadCallback;

    virtual void upload(
        UploadRequestPtr request,
        UploadCallback callback) = 0;

    virtual ~UploadHandler() {
    }

};

/*
 * Mediates access to a shared cache of chunk hashes to be used
 * by multiple ChunkHandler implementations
 */
class SIRIKATA_EXPORT SharedChunkCache {
private:
    static const unsigned int DISK_LRU_CACHE_SIZE;
    static const unsigned int MEMORY_LRU_CACHE_SIZE;

    CachePolicy* mDiskCachePolicy;
    CachePolicy* mMemoryCachePolicy;
    std::vector<CacheLayer*> mCacheLayers;
    CacheLayer* mCache;
public:
    SharedChunkCache();
    ~SharedChunkCache();
    CacheLayer* getCache();
    static SharedChunkCache& getSingleton();
    static void destroy();
};

}
}

#endif