Leaked source code of windows server 2003
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/*
* datapkt.h
*
* Copyright (c) 1997 by Microsoft Corporation, Redmond, WA
*
* Abstract:
* This is the interface file for the MCS Data Packet class. Instances of this
* class represent MCS Data Protocol Data Units (Data PDUs) as they flow through the
* system. These instances allocate the memory required to hold both
* encoded and decoded versions of the PDU, and make sure that no PDU
* is ever encoded or decoded more than once. However, they differ from normal
* packets, in that there is only one copy of the user data in the encoded
* and decoded buffers. The use of lock counts
* allows multiple objects in the system to reference and use the same
* packet object at the same time. This class inherits from the SimplePacket
* class, which is a pure virtual class.
*
* A data packet object can be created in two different ways. It can be created
* with either decoded data or encoded data. During instantiation, the
* new packet object will include the memory it will need to
* hold both the encoded and decoded data
* The DataPacket class, however, does not put any data into those buffers.
*
* When a Lock message is sent to the object, it will put encoded
* data into the encode buffer. If the packet was created
* with decoded data, then this will entail an encode operation. However,
* if the packet was created with encoded data, then it is smart enough
* to just COPY the encoded data into the internal buffer, thus avoiding
* the overhead associated with the encode operation.
*
* When a Lock message is sent to the object, it will put decoded
* data into the pre-allocated decode buffer. If the packet was created
* with encoded data, then this will entail a decode operation. However,
* if the packet was created with decoded data, then it is smart enough
* to just COPY the decoded data into the internal buffer, thus avoiding
* the overhead associated with the decode operation.
*
* When Unlock messages are received, the lock count is decremented. When a packet's
* lock count is 0, the packet deletes itself (it commits
* suicide). Note that for this reason, no other object should explicitly
* delete a packet object.
*
* Caveats:
* None.
*
* Authors:
* Christos Tsollis
*/
#ifndef _DATAPACKET_
#define _DATAPACKET_
#include "mpdutype.h"
/*
* Definition of class DataPacket.
*/
class DataPacket;
typedef DataPacket * PDataPacket;
class DataPacket : public SimplePacket
{
public:
static Void AllocateMemoryPool (long maximum_objects);
static Void FreeMemoryPool ();
PVoid operator new (size_t);
Void operator delete (PVoid object);
DataPacket (ASN1choice_t choice,
PUChar data_ptr,
ULong data_length,
UINT channel_id,
Priority priority,
Segmentation segmentation,
UINT initiator_id,
SendDataFlags flags,
PMemory memory,
PPacketError packet_error);
DataPacket( PTransportData pTransportData,
BOOL fPacketDirectionUp);
virtual ~DataPacket ();
Void SetDirection (DBBoolean packet_direction_up);
virtual PVoid GetDecodedData(void);
virtual BOOL IsDataPacket (void);
virtual int GetPDUType (void);
BOOL Equivalent (PDataPacket);
Priority GetPriority (void)
{
return ((Priority) m_DecodedPDU.u.send_data_request.
data_priority);
};
UserID GetInitiator (void)
{
return (m_DecodedPDU.u.send_data_request.initiator);
};
ChannelID GetChannelID (void)
{
return (m_DecodedPDU.u.send_data_request.channel_id);
};
Segmentation GetSegmentation (void)
{
return (m_DecodedPDU.u.send_data_request.segmentation);
};
LPBYTE GetUserData (void)
{
return ((LPBYTE) m_DecodedPDU.u.send_data_request.user_data.value);
};
UINT GetUserDataLength (void)
{
return (m_DecodedPDU.u.send_data_request.user_data.length);
};
PMemory GetMemory (void)
{
return (m_Memory);
};
BOOL IsEncodedDataBroken (void)
{
return (m_EncodedDataBroken);
};
void SetMessageType(UINT nMsgType) { m_nMessageType = nMsgType; }
UINT GetMessageType(void) { return m_nMessageType; }
protected:
static PVoid * Object_Array;
static long Object_Count;
BOOL fPreAlloc;
DomainMCSPDU m_DecodedPDU; // The decoded data PDU (w/o the user data)
PMemory m_Memory; // Memory object pointing to big buffer which contains the object's buffer.
BOOL m_fIncoming; // Does this packet represent recv data?
BOOL m_EncodedDataBroken;
UINT m_nMessageType; // for retry in CUser::SendDataIndication
};
/*
* Void AllocateMemoryPool (
* long maximum_objects);
*
* Functional Description:
* This is a static member function that should only be called during MCS
* initialization (exactly once). It allocates a memory block that will
* be used to hold all instances of this class during the operation of
* the system. This allows us to VERY efficiently allocate and destroy
* instances of this class.
*
* Formal Parameters:
* maximum_objects
* This is the maximum number of objects of this class that can exist
* in the system at the same time. This is used to determine how much
* memory to allocate to hold the objects. Once this number of
* objects exist, all calls to "new" will return NULL.
*
* Return Value:
* None.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* Void FreeMemoryPool ();
*
* Functional Description:
* This is a static member function that should only be called during a
* shutdown of MCS (exactly once). It frees up the memory pool allocated
* to hold all instances of this class. Note that calling this function
* will cause ALL existing instances of this class to be invalid (they
* no longer exist, and should not be referenced).
*
* Formal Parameters:
* None.
*
* Return Value:
* None.
*
* Side Effects:
* Any existing instances of this class are no longer valid and should not
* be referenced.
*
* Caveats:
* None.
*/
/*
* PVoid operator new (
* size_t object_size);
*
* Functional Description:
* This is an override of the "new" operator for this class. Since all
* instances of this class come from a single memory pool allocated up
* front, this function merely pops the first entry from the list of
* available objects.
*
* Formal Parameters:
* None.
*
* Return Value:
* Pointer to an object of this class, or NULL if no memory is available.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* Void operator delete (
* PVoid object);
*
* Functional Description:
* This function is used to free up a previously allocated object of this
* class. Note that it is VERY important not to call this function with an
* invalid address, because no error checking is performed. This decision
* was made due to speed requirements.
*
* Formal Parameters:
* None.
*
* Return Value:
* None.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* DataPacket( PUChar pEncodedData,
* ULong ulEncodedDataSize,
* BOOL fPacketDirectionUp,
* PPacketError pePktErr)
*
* Functional Description:
* This version of the constructor is used to create a Data Packet object
* for incomming PDUs when the packet is to be created from an encoded
* data stream containing the PDU data to be decoded.
*
* Formal Parameters:
* pEncodedData (i)
* Pointer to the input encoded PDU.
* ulEncodedDataSize (i)
* The length in bytes of the input encoded PDU.
* fPacketDirectionUp (i)
* The packet_direction_up flag indicates the initial orientation of
* the packet. Valid values are:
* TRUE - The packet's direction is up.
* FALSE - The packet's direction is down.
* pePktErr (o)
* When the constructor returns control to the calling function, this
* variable will be set to one of the return values listed below.
*
* Return Value:
* None.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* DataPacket (ASN1choice_t choice,
* PUChar data_ptr,
* ULong data_length,
* UINT channel_id,
* Priority priority,
* Segmentation segmentation,
* UINT initiator_id,
* PPacketError packet_error)
*
* Functional Description:
* This constructor is used for outgoing data packets.
* It needs to copy the data into the encoded PDU buffer
* that will be allocated by this constructor.
*
* Formal Parameters:
* choice (i)
* Either normal or uniform send data PDU
* data_ptr (i)
* Pointer to the user data for this data PDU.
* data_length (i)
* The length of the user data
* channel_id (i)
* The MCS channel on which the data will be xmitted.
* priority (i)
* Data priority
* segmentation (i)
* The segmentation bits for the packet
* initiator_id (i)
* MCS user id of the user (application) sending the data
* packet_error (o)
* Ptr to location for storing the success/failure code for the constructor.
*
* Return Value:
* None.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* ~DataPacket ()
*
* Functional Description:
* Destructor for the DataPacket class. The destructor ensures that all
* resources that have been allocated are freed.
*
* Formal Parameters:
* None.
*
* Return Value:
* None.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* GetDecodedData ()
*
* Functional Description:
* The GetDecodedData method returns a pointer to the decoded data
* buffer.
*
* Formal Parameters:
* None.
*
* Return Value:
* A pointer to the decoded data. If an decoding error occurs, this
* method will return NULL.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* GetEncodedDataLength ()
*
* Functional Description:
* This method returns the encoded data's length.
*
* Formal Parameters:
* None.
*
* Return Value:
* The number of bytes in the encoded data.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* GetDecodedDataLength ()
*
* Functional Description:
* This method returns the decoded data's length.
*
* Formal Parameters:
* None.
*
* Return Value:
* The number of bytes in the decoded data.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
#endif