DeltaRW

A DeltaRW is associated with a WorkingSetMachine and allows for sending and receiving the operations used to synchronise the mutable objects with a remote WorkingSetMachine using Operational Transformation.

A DeltaRW communicates with exactly one remote DeltaRW using a fully symmetric message based protocol.

A DeltaRW is stateful, so therefore local and remote DeltaRWs must be paired for the life of the session.

A DeltaRW is not concerned with creating or managing internal threads or sockets for IPC. Instead deltas are read/written synchronously to a given input or output archive.

A DeltaRW is defined in the Xc++ language as an $adt:

$adt+ DeltaRW
{
    void Close();

    // Reader
    InputArchive DeserialiseNextDelta(InputArchive ar, bool& appliedChanges);

    // Writer
    void Init(const VecTime& rhv);
    bool HaveChangesToSend() const;
    bool WriteNextDelta(Archive& ar);
};

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void Close()

Must be called without a lock on the CSpace. It is not necessary to have set the CSpace/PSpace in TLS.

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InputArchive DeserialiseNextDelta(InputArchive ar, bool& appliedChanges)

Read and apply the next delta from 'ar' which is an InputArchive. Sets 'appliedChanges' if changes were actually applied. Requires an exclusive lock on the associated CSpace, and CSpace/PSpace to be set in TLS

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void Init(const VecTime& rhv)

Must be called exactly once, and before all other public methods in this class. Requires an exclusive lock on the associated CSpace, and CSpace/PSpace to be set in TLS

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bool HaveChangesToSend() const

Are there changes waiting to be sent? Requires a lock on the associated CSpace, and CSpace/PSpace to be set in TLS

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bool WriteNextDelta(Archive& ar)

Write the next delta to ar. Returns false if nothing to write. Requires a lock on the associated CSpace, and CSpace/PSpace to be set in TLS