storage_delegate.h

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/*
 *
 * Copyright (c) Microsoft Corporation.
 * All rights reserved.
 *
 * This code is licensed under the MIT License.
 *
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 * of this software and associated documentation files(the "Software"), to deal
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 * to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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/**
 * @brief Defines StorageDelegate interface
 * 
 * @file storage_delegate.h
 */
 
#ifndef API_MIP_STORAGE_DELEGATE_H_
#define API_MIP_STORAGE_DELEGATE_H_
 
#include <string>
#include <vector>
 
#include "mip/common_types.h"
#include "mip/delegate_response.h"
#include "mip/mip_namespace.h"
#include "mip/storage_table.h"
 
MIP_NAMESPACE_BEGIN
 
/**
 * @brief Describes the MIP component to be used in the application.
 */
enum class MipComponent : unsigned int {
  Policy   = 0, /* For Policy sdk */
  File    = 1, /* For File sdk */
  Protection = 2, /* For Protection sdk */
};
 
/**
* @brief A delegate response type for #StorageTable
*/
typedef mip::DelegateResponse<mip::StorageTable> StorageTableResult;
 
/**
* @brief A class that defines the interface to the MIP SDK storage for caching
*/
class StorageDelegate {
public:
 
  /**
   * @brief Creates an instance of a storage table that MIP uses for caching. If a table already exists & schema doesnt match with @p allColumns , implementatiion should drop the table and re-create new one.
   * 
   * @param path Default path for mip storage. Will end in file extension returned from StorageSettings::OnDiskExtension()
   * @param mipComponent #MipComponent associated with this table.
   * @param tableName Name of the table to create.
   * @param allColumns All columns represented in the table.
   * @param encryptedColumns Represents the set of columns within @p allColumns that need to be encrypted. This argument is only populated if #CacheStorageType (configured via the profile settings) is not @p OnDiskEncrypted, 
   * otherwise the MIP SDK will internally encrypt the column data for these columns and modify their name with an 'encrypt_' prefix.
   * @param keyColumns Key columns used to identify unique table entries.
   * 
   * @return A delegate response which either contains an instance of #StorageTable or an exception.
   */
  virtual mip::StorageTableResult CreateStorageTable(
      const std::string& path,
      const MipComponent mipComponent,
      const std::string& tableName,
      const std::vector<std::string>& allColumns,
      const std::vector<std::string>& encryptedColumns,
      const std::vector<std::string>& keyColumns) const = 0;
 
  /**
   * @brief Settings used by StorageDelegate
   */
  class StorageSettings {
  public:
    /**
     * @brief Interface for configuring the storage settings.
     * 
     * @param isRemoteStore represents if store is remote. This will be taken into account for internal encryption.
     * @param isInMemoryStorageSupported Declares whether the delegate supports in-memory storage.
     * @param onDiskExtension The file extension that will be used to store the data if it is needed. Should begin with ".".
     */
    StorageSettings(
        bool isRemoteStorage,
        bool isInMemoryStorageSupported,
        const std::string& onDiskExtension = GetSqliteExtension())
        : mIsRemoteStorage(isRemoteStorage),
          mIsInMemoryStorageSupported(isInMemoryStorageSupported),
          mOnDiskExtension(onDiskExtension) {}
 
    /**
     * @brief Gets whether remote storage is used or not.
     *
     * @return whether remote storage is used or not.
     */
    bool IsRemoteStorage() const { return mIsRemoteStorage; }
 
    /**
     * @brief Gets whether the delegate supports in-memory storage.
     *
     * @return \p true if the delegate supports in-memory storage.
     */
    bool IsInMemoryStorageSupported() const { return mIsInMemoryStorageSupported; }
    
    /**
     * @brief Gets the extension that the delegate will use when storing a table on disk
     *
     * @return The extension that will be used. Default to ".sqlite3".
     * 
     * @note Extension will have "." preceding it
     */
    std::string OnDiskExtension() const { return mOnDiskExtension; }
 
    /** @cond DOXYGEN_HIDE */
    ~StorageSettings() { }
    StorageSettings() : StorageSettings(false, true, GetSqliteExtension()) {}
  private:
    bool mIsRemoteStorage;
    bool mIsInMemoryStorageSupported;
    std::string mOnDiskExtension;
    /** @endcond */
  };
 
  /**
   * @brief Gets settings used by #StorageDelegate.
   * 
   * @return settings used by #StorageDelegate.
   */
  virtual StorageSettings GetSettings() const = 0;
 
  /** @cond DOXYGEN_HIDE */
  virtual ~StorageDelegate() {}
 
protected:
  StorageDelegate() {}
  /** @endcond */
};
 
MIP_NAMESPACE_END
#endif // API_MIP_STORAGE_DELEGATE_H_