open62541/include/ua_plugin_history_data_service.h

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 *    Copyright 2018 (c) basysKom GmbH <opensource@basyskom.com> (Author: Peter Rustler)
 */

#ifndef UA_PLUGIN_HISTORY_DATA_SERVICE_H_
#define UA_PLUGIN_HISTORY_DATA_SERVICE_H_

#ifdef __cplusplus
extern "C" {
#endif

#include "ua_types.h"
#include "ua_server.h"

struct UA_HistoryDataService;
typedef struct UA_HistoryDataService UA_HistoryDataService;

struct UA_HistoryDataService {
    void *context;

    void
    (*deleteMembers)(UA_HistoryDataService *service);

    /* This function will be called when a nodes value is set.
     * Use this to insert data into your database(s) if polling is not suitable
     * and you need to get all data changes.
     * Set it to NULL if you do not need it.
     *
     * server is the server this node lives in.
     * hdsContext is the context of the UA_HistoryDataService. UA_HistoryDataService.context
     * sessionId and sessionContext identify the session which set this value.
     * nodeId is the node id for which data was set.
     * historizing is the nodes boolean flag for historizing
     * value is the new value.
     */
    void
    (*setValue)(UA_Server *server,
                void *hdsContext,
                const UA_NodeId *sessionId,
                void *sessionContext,
                const UA_NodeId *nodeId,
                UA_Boolean historizing,
                const UA_DataValue *value);

    /* This function is called if a history read is requested
     * with isRawReadModified set to false.
     * Setting it to NULL will result in a response with statuscode UA_STATUSCODE_BADHISTORYOPERATIONUNSUPPORTED.
     *
     * server is the server this node lives in.
     * hdsContext is the context of the UA_HistoryDataService. UA_HistoryDataService.context
     * sessionId and sessionContext identify the session which set this value.
     * requestHeader, historyReadDetails, timestampsToReturn, releaseContinuationPoints
     * nodesToReadSize and nodesToRead is the requested data from the client. It is from the request object.
     * response the response to fill for the client. If the request is ok, there is no need to use it.
     *          Use this to set status codes other than "Good" or other data.
     *          You find an already allocated UA_HistoryReadResult array with an UA_HistoryData object
     *          in the extension object in the size of nodesToReadSize. If you are not willing to return data,
     *          you have to delete the results array, set it to NULL and set the resultsSize to 0.
     *          Do not access historyData after that.
     * historyData is a proper typed pointer array pointing in the UA_HistoryReadResult extension object.
     *             use this to provide result data to the client.
     *             Index in the array is the same as in nodesToRead and the UA_HistoryReadResult array.
     */
    void
    (*readRaw)(UA_Server *server,
               void *hdsContext,
               const UA_NodeId *sessionId,
               void *sessionContext,
               const UA_RequestHeader *requestHeader,
               const UA_ReadRawModifiedDetails *historyReadDetails,
               UA_TimestampsToReturn timestampsToReturn,
               UA_Boolean releaseContinuationPoints,
               size_t nodesToReadSize,
               const UA_HistoryReadValueId *nodesToRead,
               UA_HistoryReadResponse *response,
               UA_HistoryData * const * const historyData);

    // Add more function pointer here.
    // For example for read_event, read_modified, read_processed, read_at_time
};

#ifdef __cplusplus
}
#endif

#endif /* UA_PLUGIN_HISTORY_DATA_SERVICE_H_ */