Resource.h

Go to the documentation of this file.

/*
 * Copyright Amazon.com, Inc. or its affiliates. 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.
 * A copy of the License is located at
 *
 *     http://aws.amazon.com/apache2.0/
 *
 * or in the "license" file accompanying this file. This file 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 ACSDKASSETMANAGER_SRC_RESOURCE_H_
#define ACSDKASSETMANAGER_SRC_RESOURCE_H_
 
#include <memory>
#include <string>
 
namespace alexaClientSDK {
namespace acsdkAssets {
namespace manager {
 
class StorageManager;
 
class Resource {
public:
    inline const std::string& getId() const {
        return m_id;
    }
 
    inline const std::string& getPath() const {
        return m_fullResourcePath;
    }
 
    inline size_t getSizeBytes() const {
        return m_sizeBytes;
    }
 
    inline bool exists() const {
        return m_sizeBytes > 0;
    }
 
private:
    static std::shared_ptr<Resource> create(
            const std::string& parentDirectory,
            const std::string& id,
            const std::string& source);
 
    static std::shared_ptr<Resource> createFromStorage(const std::string& resourceDirectory);
 
    static std::shared_ptr<Resource> createFromConfigFile(const std::string& resourceDirectory);
 
    Resource(
            const std::string& resourceDirectory,
            const std::string& resourceName,
            const std::string& id,
            size_t sizeBytes);
 
    bool saveMetadata();
 
    void erase();
 
    inline int incrementRefCount() {
        return ++m_refCount;
    }
    inline int decrementRefCount() {
        return --m_refCount;
    }
 
private:
    // The parent directory where the resource is stored, like "/some/path/abc"
    const std::string m_resourceDirectory;
    // The name of the file or directory that is stored inside the resource directory, like "resource.txt"
    const std::string m_resourceName;
    // Id of the resource, usually the checksum, like "abc"
    const std::string m_id;
    // Size of the entire resource directory
    size_t m_sizeBytes;
    // The complete path of the resource including the name, like "/some/path/abc/resource.txt"
    std::string m_fullResourcePath;
    // Count of how many requesters reference this resource.
    int m_refCount;
 
    // it's important that the creation, ref counting, and deletion of resource happens only by the Storage Manager.
    friend StorageManager;
};
 
}  // namespace manager
}  // namespace acsdkAssets
}  // namespace alexaClientSDK
 
#endif  // ACSDKASSETMANAGER_SRC_RESOURCE_H_