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Inside Macintosh: Networking /

Chapter 6 - AppleTalk Transaction Protocol (ATP) / ATP Reference

Data Structures

The Buffer Data Structure

The buffer data structure (BDS) is an array of type BDSElement containing up to eight records, each of which is used to hold a response packet. You create a BDS to hold
the response data that you send using the PSendResponse function. You also create
a BDS to receive the response packets that you request through a PSendRequest or PNSendRequest function. You can use the BuildBDS function to create this data structure, or you can create the data structure in Pascal.

TYPE  BDSElement = 
RECORD
   buffSize: Integer;
   buffPtr: Ptr;
   dataSize: Integer;
   userBytes: Longint;
END;
BDSType = ARRAY[0..7] OF BDSElement;
BDSPtr = ^BDSType;
BitMapType = PACKED ARRAY[0..7] OF Boolean;

Field Description

buffSize

The size in bytes of the buffer.

buffPtr

A pointer to the buffer.

dataSize

The size of the data received.

userBytes

Up to 4 bytes of additional data separate from the response data.