ModelPointCommon_.h

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#ifndef Cpl_Dm_ModelPointBase_h_
#define Cpl_Dm_ModelPointBase_h_
/*-----------------------------------------------------------------------------
* This file is part of the Colony.Core Project.  The Colony.Core Project is an
* open source project with a BSD type of licensing agreement.  See the license
* agreement (license.txt) in the top/ directory or on the Internet at
* http://integerfox.com/colony.core/license.txt
*
* Copyright (c) 2014-2022  John T. Taylor
*
* Redistributions of the source code must retain the above copyright notice.
*----------------------------------------------------------------------------*/
/** @file */
 
 
#include "Cpl/Dm/ModelPoint.h"
#include "Cpl/Dm/ModelDatabase.h"
#include "Cpl/Dm/Subscriber.h"
#include "Cpl/Container/DList.h"
#include <stdint.h>
#include <stdlib.h>
 
///
namespace Cpl {
///
namespace Dm {
 
 
/** This concrete class provide common infrastructure for a Model Point.
 */
class ModelPointCommon_ : public Cpl::Dm::ModelPoint
{
protected:
    /// Constructor
    ModelPointCommon_( ModelDatabase& myModelBase,
                       const char*    symbolicName,
                       void*          myDataPtr,
                       size_t         dataSizeInBytes,
                       bool           isValid = false );
 
public:
    /// See Cpl::Dm::ModelPoint
    const char* getName() const noexcept;
 
    /// See Cpl::Dm::ModelPoint.  This method IS thread safe.
    size_t getSize() const noexcept;
 
    /// See Cpl::Dm::ModelPoint
    uint16_t getSequenceNumber() const noexcept;
 
    /// See Cpl::Dm::ModelPoint
    uint16_t touch() noexcept;
 
    /// See Cpl::Dm::ModelPoint
    uint16_t setInvalid( LockRequest_T lockRequest = eNO_REQUEST ) noexcept;
 
    /// See Cpl::Dm::ModelPoint
    bool isNotValid( uint16_t* seqNumPtr=0 ) const noexcept;
 
    /// See Cpl::Dm::ModelPoint
    bool isLocked() const noexcept;
 
    /// See Cpl::Dm::ModelPoint
    uint16_t setLockState( LockRequest_T lockRequest ) noexcept;
 
    /// See Cpl::Dm::ModelPoint 
    size_t getExternalSize( bool includeLockedState = false ) const noexcept;
 
    /// See Cpl::Dm::ModelPoint.  Note: The implementation does NOT account for Endianess, i.e. assumes the 'platform' is the same for export/import
    size_t exportData( void* dstDataStream, size_t maxDstLength, uint16_t* retSequenceNumber = 0, bool includeLockedState = false ) const noexcept;
 
    /// See Cpl::Dm::ModelPoint.  Note: The implementation does NOT account for Endianess, i.e. assumes the 'platform' is the same for export/import
    size_t importData( const void* srcDataStream, size_t srcLength, uint16_t* retSequenceNumber = 0, bool includeLockedState = false ) noexcept;
 
    /// See Cpl::Dm::ModelPoint
    void genericAttach( SubscriberApi& observer, uint16_t initialSeqNumber=SEQUENCE_NUMBER_UNKNOWN ) noexcept;
 
    /// See Cpl::Dm::ModelPoint
    void genericDetach( SubscriberApi& observer ) noexcept;
 
    /// See Cpl::Dm::ModelPoint
    bool toJSON( char* dst, size_t dstSize, bool& truncated, bool verbose=true, bool pretty=false ) noexcept;
 
protected:
    /** This method is used to read the MP contents and synchronize
        the observer with the current MP contents.  This method should ONLY be
        used in the notification callback method and the 'observerToSync'
        argument MUST be the argument provided by the callback method
 
        Note: The observer will be subscribed for change notifications after
              this call.
     */
    inline bool readAndSync( void* dstData, size_t dstSize, SubscriberApi& observerToSync )
    {
        uint16_t seqNum;
        bool result = readData( dstData, dstSize , &seqNum );
        attachSubscriber( observerToSync, seqNum );
        return result;
    }
 
public:
    /** This method is used to test the validate state of the MP and synchronize
        the observer with the current MP contents.  This method should ONLY be
        used in the notification callback method and the 'observerToSync'
        argument MUST be the argument provided by the callback method
 
        Note: The observer will be subscribed for change notifications after
              this call
     */
    inline bool isNotValidAndSync( SubscriberApi& observerToSync )
    {
        uint16_t seqNum;
        bool result = isNotValid( &seqNum );
        attachSubscriber( observerToSync, seqNum );
        return result;
    }
 
 
protected:
    /// See Cpl::Dm::ModelPoint
    bool readData( void* dstData, size_t dstSize, uint16_t* seqNumPtr=0 ) const noexcept;
 
    /// See Cpl::Dm::ModelPoint
    uint16_t writeData( const void* srcData, size_t srcSize, LockRequest_T lockRequest = eNO_REQUEST ) noexcept;
 
    /// Updates the MP with the valid-state/data from 'src'. Note: the src.lock state is NOT copied
    virtual uint16_t copyDataAndStateFrom( const ModelPointCommon_& src, LockRequest_T lockRequest ) noexcept;
 
    /// See Cpl::Dm::ModelPoint
    void attachSubscriber( SubscriberApi& observer, uint16_t initialSeqNumber=SEQUENCE_NUMBER_UNKNOWN ) noexcept;
 
    /// See Cpl::Dm::ModelPoint 
    void detachSubscriber( SubscriberApi& observer ) noexcept;
 
    /// See Cpl::Dm::ModelPoint
    void copyDataTo_( void* dstData, size_t dstSize ) const noexcept;
 
    /// See Cpl::Dm::ModelPoint
    void copyDataFrom_( const void* srcData, size_t srcSize ) noexcept;
 
    
    /// See Cpl::Dm::ModelPoint. Note: This implementation does NOT work if the any of the data content are floats/double data types
    bool isDataEqual_( const void* otherData ) const noexcept;
 
    /// See Cpl::Dm::ModelPoint.  
    const void* getImportExportDataPointer_() const noexcept;
 
    /// See Cpl::Dm::ModelPoint.  
    size_t getInternalDataSize_() const noexcept;
 
public:
    /// See Cpl::Dm::ModelPoint
    void processSubscriptionEvent_( SubscriberApi& subscriber, Event_T event ) noexcept;
 
 
protected:
    /** Internal helper method that completes the data update process as well
        as ensuring any change notifications get generated.  Note: This method
        ALWAYS sets the MP's state to 'valid'
 
        This method is NOT thread safe.
     */
    virtual void processDataUpdated() noexcept;
 
    /** Internal helper method that handles generating change notifications
        when the Model Point's data/state has changed.
 
        This method is NOT thread safe.
     */
    virtual void processChangeNotifications() noexcept;
 
    /** Internal helper method that advances/updates the Model Point's
        sequence number.
 
        This method is NOT thread safe.
     */
    virtual void advanceSequenceNumber() noexcept;
 
    /** Internal helper method that manages testing and updating the locked
        state.
 
        Rules:
        1) If 'lockRequest' is eNO_REQUEST, the method only returns true if
           the MP is in the unlocked state
        2) If 'lockRequest' is eLOCK, the method only returns if the MP is in
           the unlocked state.  In addition, when true is returned the MP is
           put into the locked state.
        3) If 'lockRequest' is eUNLOCK, the method always returns true and
           the MP is left in the unlocked state.
 
        This method is NOT thread safe.
     */
    virtual bool testAndUpdateLock( LockRequest_T lockRequest ) noexcept;
 
 
protected:
    /// Helper FSM method
    virtual void transitionToNotifyPending( SubscriberApi& subscriber ) noexcept;
 
    /// Helper FSM method
    virtual void transitionToSubscribed( SubscriberApi& subscriber ) noexcept;
 
    /// Helper method when converting MP to a JSON string
    virtual JsonDocument& beginJSON( bool isValid, bool locked, uint16_t seqnum, bool verbose=true ) noexcept;
 
    /// Helper method when converting MP to a JSON string
    virtual void endJSON( char* dst, size_t dstSize, bool& truncated, bool verbose=true, bool pretty=false ) noexcept;
 
    /** Helper method that a child a class can override to change behavior when
        an MP is set to the invalid state.  The default behavior is to zero out
        the data (i.e. perform a memset(m_dataPtr,0, m_dataSize) call on the data)
     */
    virtual void hookSetInvalid() noexcept;
 
 
protected:
    /// List of Active Subscribers
    Cpl::Container::DList<SubscriberApi>    m_subscribers;
 
    /// The model point's symbolic name
    const char*                             m_name;
 
    /// Reference to the containing Model Base
    ModelDatabase&                          m_modelDatabase;
 
    /// Reference to my Data
    void*                                   m_dataPtr;
 
    /// Size of my data
    size_t                                  m_dataSize;
 
    /// Sequence number used for tracking changes in the Point data
    uint16_t                                m_seqNum;
 
    /// Locked state
    bool                                    m_locked;
 
    /// valid/invalid state
    bool                                    m_valid;
};
 
};      // end namespaces
};
#endif  // end header latch