RpcReader(3I)						    InterViews Reference Manual 					     RpcReader(3I)

NAME

       RpcReader - read RPC requests from a client

SYNOPSIS

       #include <Dispatch/rpcreader.h>

DESCRIPTION

       An  RpcReader  reads  RPC  requests from an rpcstream which represents a connection to a client.  When it reads an RPC request, it uses the
       request number to look up the address of a function in an array and calls that function to unmarshall the request's arguments  and  execute
       the request.

       An  RpcReader is not instantiable; you have to implement a derived class which initializes the function array with addresses of static mem-
       ber functions to unmarshall RPC requests and which defines the action to be performed when the client closes the connection.  The  function
       array looks like this:

	    typedef void (*PF)(RpcReader*, RpcHdr&, rpcstream&);
	    PF* _function;

       Each  function  stored in the array should extract any arguments needed by the RPC request from the rpcstream, execute the RPC request, and
       insert any return values into the rpcstream so they can be sent back to the client.

CONSTRUCTORS

       RpcReader(rpcstream* client, int nfcns)
       RpcReader(int fd, int nfcns, boolean binary = true)
	      If given a non-nil rpcstream, prepare to read RPC requests from the client using it.  If given a nil rpcstream,  just  allocate  the
	      function	array.	 If  given  a  file  descriptor, create a new rpcstream and prepare to read RPC requests from the client using it.
	      ``nfcns'' sets the size of the function array that each constructor allocates.

PROTECTED OPERATIONS

       virtual int inputReady(int)
	      Read an RPC request (only one request per call so the program can service RPC requests from  multiple  connections  in  round  robin
	      fashion).   Look	up  the  appropriate  function	in  the  reader's or another reader's function array and call it to handle the RPC
	      request.	Return the appropriate status to tell the Dispatcher whether to detach the RpcReader, call inputReady again, or  wait  for
	      new data before calling inputReady again.  A derived class should not need to redefine this function.

       virtual RpcReader* map(unsigned long reader)
	      You  can	redefine  this	function  to change which reader executes an RPC request after it's read.  Ordinarily the same reader that
	      reads an RPC request also executes it, but you can hand the request off to another reader as well.

       virtual void connectionClosed(int fd) = 0
	      You have to define this function since it may be your only chance to perform cleanup (such as deleting this) when the client  closes
	      the connection.

SEE ALSO

       RpcHdr(3I), RpcService(3I), rpcstream(3I)

InterViews							   27 March 1991						     RpcReader(3I)