#include "precomp.h"
DEBUG_FILEZONE(ZONE_T120_MCSNC);
/*
* channel.cpp
*
* Copyright (c) 1993 - 1995 by DataBeam Corporation, Lexington, KY
*
* Abstract:
* This is the implementation file for class Channel. It contains the
* code necessary to implement static and assigned channels in the
* MCS system.
*
* This is also to be the base class for other classes that represent
* channels in the system. Therefore, there will be times when some
* of these member functions are overridden to provide different
* behavior. These derived classes may or may not invoke the operations
* in this class.
*
* Protected Instance Variables:
* Channel_ID
* This instance variable contains the channel ID that is associated
* with a given instance of this class.
* m_pDomain
* This is a pointer to the local provider. Note that no messages
* ever sent to this provider. This pointer is used as a parameter
* whenever other MCS commands are issued, since this class acts on
* behalf of the local provider.
* m_pConnToTopProvider
* This is a pointer to the Top Provider. This is used when it is
* necessary to send requests to the Top Provider.
* m_pChannelList2
* This is a reference to the channel list that is owned and maintained
* by the parent domain. It is NEVER modified by this class.
* m_JoinedAttachmentList
* This is a container that contains the list of attachments currently
* joined to the channel.
*
* Private Member Functions:
* None.
*
* Caveats:
* None.
*
* Author:
* James P. Galvin, Jr.
*/
/*
* Channel ()
*
* Public
*
* Functional Description:
* This is the primary constructor for the Channel class. It simply
* initializes the instance variable to valid values. It leaves the
* attachment list empty.
*/
Channel::Channel (
ChannelID channel_id,
PDomain local_provider,
PConnection top_provider,
CChannelList2 *channel_list,
CAttachmentList *attachment_list)
:
Channel_ID (channel_id),
m_pDomain(local_provider),
m_pConnToTopProvider(top_provider),
m_pChannelList2(channel_list),
m_pAttachmentList(attachment_list)
{
}
/*
* Channel ()
*
* Public
*
* Functional Description:
* This version of the constructor is used to create a Channel object
* with an existing attachment. It is otherwise the same as the primary
* constructor above.
*/
Channel::Channel (
ChannelID channel_id,
PDomain local_provider,
PConnection top_provider,
CChannelList2 *channel_list,
CAttachmentList *attachment_list,
PConnection pConn)
:
Channel_ID (channel_id),
m_pDomain(local_provider),
m_pConnToTopProvider(top_provider),
m_pChannelList2(channel_list),
m_pAttachmentList(attachment_list)
{
/*
* Add the initial attachment to the attachment list.
*/
if (pConn != NULL)
m_JoinedAttachmentList.Append(pConn);
}
/*
* ~Channel ()
*
* Public
*
* Functional Description:
* If the object is destroyed before the attachment list is empty, it is
* the responsibility of this destructor to issue channel leave indications
* to all locally joined users.
*/
Channel::~Channel ()
{
CAttachment *pAtt;
//DWORD type;
/*
* Iterate through the joined attachment list sending channel leave
* indications to all users who are locally attached to this provider.
*/
m_JoinedAttachmentList.Reset();
while (NULL != (pAtt = m_JoinedAttachmentList.Iterate()))
{
if (m_pAttachmentList->Find(pAtt) && pAtt->IsUserAttachment())
{
PUser pUser = (PUser) pAtt;
pUser->ChannelLeaveIndication(REASON_CHANNEL_PURGED, Channel_ID);
}
}
}
/*
* Channel_Type GetChannelType ()
*
* Public
*
* Functional Description:
* This function returns the type of the channel. For a Channel object,
* this will always be either STATIC_CHANNEL or ASSIGNED_CHANNEL, depending
* on the value of the channel ID.
*/
Channel_Type Channel::GetChannelType ()
{
/*
* T.125 specifies that channels from 1 to 1000 are static. The rest
* are dynamic (for this type of Channel object, that equates to
* assigned).
*/
return (Channel_ID <= 1000) ? STATIC_CHANNEL : ASSIGNED_CHANNEL;
}
/*
* BOOL IsValid ()
*
* Public
*
* Functional Description:
* This function returns TRUE if the Channel object is still valid, or
* FALSE if it is ready to be deleted.
*/
BOOL Channel::IsValid ()
{
CAttachment *pAtt;
CAttachmentList deletion_list;
/*
* Iterate through the joined attachment list, building a list of those
* attachments in the list that are no longer valid.
*/
m_JoinedAttachmentList.Reset();
while (NULL != (pAtt = m_JoinedAttachmentList.Iterate()))
{
if (m_pAttachmentList->Find(pAtt) == FALSE)
deletion_list.Append(pAtt);
}
/*
* Iterate through the deletion list, removing all those attachments that
* were found to be invalid above.
*/
while (NULL != (pAtt = deletion_list.Get()))
{
m_JoinedAttachmentList.Remove(pAtt);
}
return (! m_JoinedAttachmentList.IsEmpty());
}
/*
* Void IssueMergeRequest ()
*
* Public
*
* Functional Description:
* This member function is used to cause the Channel object to issue a
* merge request to the pending top provier.
*/
Void Channel::IssueMergeRequest ()
{
Channel_Type channel_type;
ChannelAttributes channel_attributes;
CChannelAttributesList merge_channel_list;
CChannelIDList purge_channel_list;
if (m_pConnToTopProvider != NULL)
{
/*
* Fill in the fields of the channel attributes structure so that it
* accurately describes this channel. Then put the structure into the
* merge channel list.
*/
channel_type = GetChannelType ();
channel_attributes.channel_type = channel_type;
switch (channel_type)
{
case STATIC_CHANNEL:
channel_attributes.u.static_channel_attributes.channel_id =
Channel_ID;
break;
case ASSIGNED_CHANNEL:
channel_attributes.u.assigned_channel_attributes.channel_id =
Channel_ID;
break;
}
merge_channel_list.Append(&channel_attributes);
/*
* Send the merge request to the indicated provider.
*/
m_pConnToTopProvider->MergeChannelsRequest(&merge_channel_list, &purge_channel_list);
}
}
/*
* Void ChannelJoinRequest ()
*
* Public
*
* Functional Description:
* This function is used to add a new attachment to the attachment list.
* If the user ID is valid, this routine will also issue an automatic
* join confirm to the user.
*/
Void Channel::ChannelJoinRequest (
CAttachment *pOrigAtt,
UserID uidInitiator,
ChannelID channel_id)
{
/*
* Make sure the attachment isn't already in the list before adding it.
*/
if (m_JoinedAttachmentList.Find(pOrigAtt) == FALSE)
{
TRACE_OUT (("Channel::ChannelJoinRequest: "
"user %04X joining channel %04X", (UINT) uidInitiator, (UINT) Channel_ID));
m_JoinedAttachmentList.Append(pOrigAtt);
}
/*
* If the user ID is valid, then send a join confirm to the initiating
* attachment. Note that setting the user ID to 0 is a way of disabling
* this behavior. This is sometimes useful when adding attachments during
* a domain merge.
*/
if (uidInitiator != 0)
{
pOrigAtt->ChannelJoinConfirm(RESULT_SUCCESSFUL, uidInitiator, channel_id, Channel_ID);
}
}
/*
* Void ChannelJoinConfirm ()
*
* Public
*
* Functional Description:
* This function performs the same operation as JoinRequest above.
*/
Void Channel::ChannelJoinConfirm (
CAttachment *pOrigAtt,
Result,
UserID uidInitiator,
ChannelID requested_id,
ChannelID)
{
/*
* Make sure the attachment isn't already in the list before adding it.
*/
if (m_JoinedAttachmentList.Find(pOrigAtt) == FALSE)
{
TRACE_OUT (("Channel::ChannelJoinConfirm: "
"user %04X joining channel %04X", (UINT) uidInitiator, (UINT) Channel_ID));
m_JoinedAttachmentList.Append(pOrigAtt);
}
/*
* Send a join confirm to the initiating attachment.
*/
pOrigAtt->ChannelJoinConfirm(RESULT_SUCCESSFUL, uidInitiator, requested_id, Channel_ID);
}
/*
* Void ChannelLeaveRequest ()
*
* Public
*
* Functional Description:
* This function is used to remove an attachment from the attachment list.
* A leave request will also be issued upward (unless this is the Top
* Provider).
*/
Void Channel::ChannelLeaveRequest (
CAttachment *pOrigAtt,
CChannelIDList *)
{
CChannelIDList channel_leave_list;
/*
* Make sure the attachment is in the list before trying to remove it.
*/
if (m_JoinedAttachmentList.Remove(pOrigAtt))
{
TRACE_OUT (("Channel::ChannelLeaveRequest: leaving channel %04X", Channel_ID));
/*
* Remove the attachment from the list.
*/
/*
* If this results in an empty list, then we have more work to do.
*/
if (m_JoinedAttachmentList.IsEmpty())
{
/*
* If this is not the Top Provider, send a leave request upward
* to the Top Provider.
*/
if (! IsTopProvider())
{
TRACE_OUT (("Channel::ChannelLeaveRequest: "
"sending ChannelLeaveRequest to Top Provider"));
channel_leave_list.Append(Channel_ID);
m_pConnToTopProvider->ChannelLeaveRequest(&channel_leave_list);
}
}
}
}
/*
* Void SendDataRequest ()
*
* Public
*
* Functional Description:
* This function is used to send data through the channel.
*/
Void Channel::SendDataRequest (
CAttachment *pOrigAtt,
UINT type,
PDataPacket data_packet)
{
CAttachment *pAtt;
ASSERT (Channel_ID == data_packet->GetChannelID());
/*
* If this is not the Top Provider, forward the data upward.
*/
if (m_pConnToTopProvider != NULL)
m_pConnToTopProvider->SendDataRequest(data_packet);
/*
* Iterate through the attachment list, sending the data to all
* the attachments (except for one from whence the data came).
*/
m_JoinedAttachmentList.Reset();
while (NULL != (pAtt = m_JoinedAttachmentList.Iterate()))
{
if ((pAtt != pOrigAtt) || (type != MCS_SEND_DATA_INDICATION))
{
pAtt->SendDataIndication(type, data_packet);
}
}
}
/*
* Void SendDataIndication ()
*
* Public
*
* Functional Description:
* This function is used to send data through the channel.
*/
Void Channel::SendDataIndication (
PConnection,
UINT type,
PDataPacket data_packet)
{
CAttachment *pAtt;
ASSERT (Channel_ID == data_packet->GetChannelID());
/*
* Iterate through the attachment list, sending the data to all
* the attachments.
*/
m_JoinedAttachmentList.Reset();
while (NULL != (pAtt = m_JoinedAttachmentList.Iterate()))
{
pAtt->SendDataIndication(type, data_packet);
}
}