|
|
/*
* privchnl.h * * Copyright (c) 1993 - 1995 by DataBeam Corporation, Lexington, KY * * Abstract: * This is the interface file for the PrivateChannel class. Objects of * this class represent private channels in the MCS environment. This * class inherits much of its behavior from class Channel. However, * objects of this class maintain a list of authorized users, and do not * allow any other users to use the channel. Users that are not part * of the authorized user list may not join the channel, nor may they * even send data on the channel. * * Private channels are created as the result of a user issuing a * channel convene request. This user is known as the channel manager. * Only the channel manager may modify the authorized user list, and * only the channel manager may destroy (disband) the private channel. * * The channel adds users to the authorized user list by issuing a * channel admit request. Users are removed from this list when the * channel manager issues a channel expel request. * * Private channel objects will exist in the information base of all * providers who contain either an admitted user or the channel * manager in their sub-tree. Requests pass upward to the Top Provider * who issues the appropriate indications downward to manage the * information base synchronization process. * * Private channel objects restrict the joining of channel by overriding * the join commands. They restrict the transmission of data by * overriding the send data commands. * * Caveats: * None. * * Author: * James P. Galvin, Jr. */ #ifndef _PRIVATECHANNEL_
#define _PRIVATECHANNEL_
/*
* This is the class definition for the PrivateChannel class. */ class PrivateChannel : public Channel { public: PrivateChannel ( ChannelID channel_id, UserID channel_manager, PDomain local_provider, PConnection top_provider, CChannelList2 *channel_list, CAttachmentList *attachment_list); PrivateChannel ( ChannelID channel_id, UserID channel_manager, PDomain local_provider, PConnection top_provider, CChannelList2 *channel_list, CAttachmentList *attachment_list, CUidList *admitted_list, PConnection pConn); virtual ~PrivateChannel (); virtual Channel_Type GetChannelType (); virtual BOOL IsValid (); virtual CAttachment *GetAttachment(void); virtual Void IssueMergeRequest (); virtual Void ChannelJoinRequest ( CAttachment *originator, UserID uidInitiator, ChannelID channel_id); Void ChannelDisbandRequest ( CAttachment *originator, UserID uidInitiator, ChannelID channel_id); Void ChannelDisbandIndication ( ChannelID channel_id); Void ChannelAdmitRequest ( CAttachment *originator, UserID uidInitiator, ChannelID channel_id, CUidList *user_id_list); Void ChannelAdmitIndication ( PConnection originator, UserID uidInitiator, ChannelID channel_id, CUidList *user_id_list); Void ChannelExpelRequest ( CAttachment *originator, UserID uidInitiator, ChannelID channel_id, CUidList *user_id_list); Void ChannelExpelIndication ( PConnection originator, ChannelID channel_id, CUidList *user_id_list); virtual Void SendDataRequest ( CAttachment *originator, UINT type, PDataPacket data_packet); private: BOOL ValidateUserID ( UserID user_id); Void BuildAttachmentLists ( CUidList *user_id_list, CAttachmentList *local_attachment_list, CAttachmentList *remote_attachment_list); Void BuildUserIDList ( CUidList *user_id_list, CAttachment *attachment, CUidList *user_id_subset);
private:
UserID m_uidChannelManager; CUidList m_AuthorizedUserList; BOOL m_fDisbandRequestPending; };
/*
* PrivateChannel ( * ChannelID channel_id, * UserID channel_manager, * PDomain local_provider, * PConnection top_provider, * PChannelList channel_list, * PAttachmentList attachment_list) * * Functional Description: * This is the normal constructor for the PrivateChannel class. It simply * initializes the instance variables that identify the channel, the local * provider, the top provider, and the channel manager. The attachment * list is empty by default (meaning that no users have joined the * channel). The authorized user list is also empty by default. * * Upon successful construction of this object, a channel convene confirm * is automatically issued to the channel manager, if it is in the * sub-tree of this provider. * * Formal Parameters: * channel_id (i) * This is the ID of the channel object. By keeping track of this * internally, it doesn't have to be passed in for every operation. * channel_manager (i) * This is the user ID of the channel manager. Only this user is * permitted to expand or reduce the size of the authorized user list. * local_provider (i) * This is the identity of the local provider. A PrivateChannel object * needs this since it issues MCS commands on behalf of the local * provider. * top_provider (i) * This is a pointer to the top provider. This is used by the * PrivateChannel object when it needs to issue a request to the Top * Provider. * channel_list (i) * This is a pointer to the domain's channel list, which identifies * all valid channels in the domain. This is used by channel objects * to validate user IDs. * attachment_list (i) * This is a pointer to the domain's attachment list, which identifies * all valid attachments in the domain. This is used by channel * objects to validate joined attachments. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* PrivateChannel ( * ChannelID channel_id, * UserID channel_manager, * PDomain local_provider, * PConnection top_provider, * PChannelList channel_list, * PAttachmentList attachment_list, * CUidList *admitted_list, * PCommandTarget attachment) * * Functional Description: * This is a secondary version of the constructor that is used only during * merge operations. The only difference between this one and the one * above is that this one allows the specification of an initial * attachment. This allows a PrivateChannel object to be constructed with * an attachment already joined to the channel. * * This version of the constructor will not issue a channel convene confirm * or a channel join confirm to the user. * * Formal Parameters: * channel_id (i) * This is the ID of the channel object. By keeping track of this * internally, it doesn't have to be passed in for every operation. * channel_manager (i) * This is the user ID of the channel manager. Only this user is * permitted to expand or reduce the size of the authorized user list. * local_provider (i) * This is the identity of the local provider. A PrivateChannel object * needs this since it issues MCS commands on behalf of the local * provider. * top_provider (i) * This is a pointer to the top provider. This is used by the * PrivateChannel object when it needs to issue a request to the Top * Provider. * channel_list (i) * This is a pointer to the domain's channel list, which identifies * all valid channels in the domain. This is used by channel objects * to validate user IDs. * attachment_list (i) * This is a pointer to the domain's attachment list, which identifies * all valid attachments in the domain. This is used by channel * objects to validate joined attachments. * admitted_list (i) * This is a list of users that are admitted to the channel at the * time of the merge. * attachment (i) * This is the initial attachment for the channel. A channel join * confirm is NOT issued to the attachment. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* ~PrivateChannel () * * Functional Description: * This is the PrivateChannel class destructor. It does nothing at this * time. The base class constructor takes care of clearing the attachment * list. * * Formal Parameters: * None. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* Channel_Type GetChannelType () * * Functional Description: * This virtual member function returns the type of the channel. For this * class it will always be PRIVATE_CHANNEL. * * Formal Parameters: * None. * * Return Value: * PRIVATE_CHANNEL * * Side Effects: * None. * * Caveats: * None. */ /*
* BOOL IsValid () * * Functional Description: * This function will return TRUE until the channel is disbanded. Then * it will return FALSE to indicate that the channel object can be deleted * from the domain infirmation base. * * Formal Parameters: * None. * * Return Value: * TRUE if channel still valid. * FALSE if the channel has been disbanded. * * Side Effects: * None. * * Caveats: * None. */
/*
* CAttachment *GetAttachment () * * Functional Description: * This function returns the attachment which leads to the private channel * manager. If the channel manager is not in the sub-tree of this * provider, it returns NULL. * * Formal Parameters: * None. * * Return Value: * Attachment that leads to channel manager, or NULL if channel manager is * not in the sub-tree of this provider. * * Side Effects: * None. * * Caveats: * None. */
/*
* Void IssueMergeRequest () * * Functional Description: * This member function causes the PrivateChannel object to issue a merge * request to the top provider. It will pack the appropriate local * information into the command. * * Formal Parameters: * None. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* Void ChannelJoinRequest ( * PCommandTarget originator, * UserID uidInitiator, * ChannelID channel_id) * * Functional Description: * This function is invoked when a user tries to join the private channel * associated with a PrivateChannel object. The originator of the request * will only be permitted to join if their user ID is contained in the * authorized user list, If it does, then the originator will be permitted * to join. * * If this provider is not the Top Provider, then the request will be * forwarded upward to the Top Provider. If this is the Top Provider, * the a channel join confirm will be issued back to the requesting * user. * * Formal Parameters: * originator (i) * This is the attachment from which this command originated. * uidInitiator (i) * This is the user ID of the user joining the channel. This must * be contained in the authorized user list maintained by the object, * or the request will automatically be rejected. * channel_id (i) * This is the channel being acted upon. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* Void ChannelDisbandRequest ( * PCommandTarget originator, * UserID uidInitiator, * ChannelID channel_id) * * Functional Description: * This function is invoked when a user tries to destroy an existing * private channel. This is only permitted if the operation is invoked * by the manager of the specified private channel. * * If this provider is not the Top Provider, then the request will be * forwarded upward to the Top Provider. * * Formal Parameters: * originator (i) * This is the attachment from which this command originated. * uidInitiator (i) * This is the user ID of the user disbanding the channel. This must * be the same as the user ID of the private channel manager, or the * request will automatically be rejected. * channel_id (i) * This is the channel being acted upon. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* Void ChannelDisbandIndication ( * PCommandTarget originator, * ChannelID channel_id) * * Functional Description: * This function is invoked when the Top Provider determines the need to * destroy a private channel. This may be done in response to a * disband request from the channel manager, or it may be done for * other reasons (such as the channel manager detaching from the domain). * * Formal Parameters: * originator (i) * This is the attachment from which this command originated. * channel_id (i) * This is the channel being acted upon. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* Void ChannelAdmitRequest ( * PCommandTarget originator, * UserID uidInitiator, * ChannelID channel_id, * CUidList *user_id_list) * * Functional Description: * This function is invoked when a user tries to expand the authorized * user list of a private channel. This operation will only be permitted * if the uidInitiator is the same as the user ID of the private channel * manager. * * If this is the Top Provider, this request will be serviced locally, * resulting in the transmission of a channel admit indication to all * downward attachments that contain an admitted user in their sub-tree. * If this is not the Top Provider, ths request will forwarded toward * the Top Provider once the request has been validated. * * Formal Parameters: * originator (i) * This is the attachment from which this command originated. * uidInitiator (i) * This is the user ID of the user who is attempting to add users to * the authorized user list. This must be the same as the user ID * represented by the object, or the request will automatically be * rejected. * channel_id (i) * This is the channel being acted upon. * user_id_list (i) * This is a list containing the IDs of the users to added to the * user list. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* Void ChannelAdmitIndication ( * PCommandTarget originator, * UserID uidInitiator, * ChannelID channel_id, * CUidList *user_id_list) * * Functional Description: * This function is invoked by the Top Provider upon reception of a * channel admit request from the legitimate manager of a private channel. * It travels downward toward any providers that contain an admitted user * in their sub-tree. * * Formal Parameters: * originator (i) * This is the attachment from which this command originated. * uidInitiator (i) * This is the user ID of the user who is attempting to add users to * the authorized user list. This must be the same as the user ID * represented by the object, or the request will automatically be * rejected. * channel_id (i) * This is the channel being acted upon. * user_id_list (i) * This is a list containing the IDs of the users to added to the * user list. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* Void ChannelExpelRequest ( * PCommandTarget originator, * UserID uidInitiator, * ChannelID channel_id, * CUidList *user_id_list) * * Functional Description: * This function is invoked when a user tries to shrink the authorized * user list of a private channel. This operation will only be permitted * if the uidInitiator is the same as the user ID of the private channel * manager. * * If this is the Top Provider, this request will be serviced locally, * resulting in the transmission of a channel admit indication to all * downward attachments that contain an admitted user in their sub-tree. * If this is not the Top Provider, ths request will forwarded toward * the Top Provider once the request has been validated. * * Formal Parameters: * originator (i) * This is the attachment from which this command originated. * uidInitiator (i) * This is the user ID of the user who is attempting to remove users * from the authorized user list. This must be the same as the user ID * represented by the object, or the request will automatically be * rejected. * channel_id (i) * This is the channel being acted upon. * user_id_list (i) * This is a list containing the IDs of the users to removed from the * user list. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* Void ChannelExpelIndication ( * PCommandTarget originator, * ChannelID channel_id, * CUidList *user_id_list) * * Functional Description: * This function is invoked by the Top Provider upon reception of a * channel expel request from the legitimate manager of a private channel. * It travels downward toward any providers that contain (or used to * contain) an admitted user in their sub-tree. * * Formal Parameters: * originator (i) * This is the attachment from which this command originated. * uidInitiator (i) * This is the user ID of the user who is attempting to remove users * from the authorized user list. This must be the same as the user ID * represented by the object, or the request will automatically be * rejected. * channel_id (i) * This is the channel being acted upon. * user_id_list (i) * This is a list containing the IDs of the users to removed from the * user list. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */
/*
* Void SendDataRequest ( * PCommandTarget originator, * UINT type, * PDataPacket data_packet) * * Functional Description: * This function is called when it is necessary to send data through the * channel that this PrivateChannel object represents. The identity of * the requesting user will be validated to make sure the user is allowed * to send data on the private channel. If so, then the request is * passed to the Channel class SendDataRequest to be processed. * * Formal Parameters: * originator (i) * This is the attachment from which the data came. * type (i) * Normal or uniform send data request. * data_packet (i) * This is a pointer to a DataPacket object containing the channel * ID, the User ID of the data sender, segmentation flags, priority of * the data packet and a pointer to the packet to be sent. * * Return Value: * None. * * Side Effects: * None. * * Caveats: * None. */ #endif
|