SimpleRequest.h

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 *  Copyright 2018 Rice University                                           *
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#ifndef SIMPLE_REQUEST_H
#define SIMPLE_REQUEST_H

#include "PDBLogger.h"

// This templated function makes it easy to write a simple network client that asks a request,
// then gets a result.  See, for example, CatalogClient.cc for an example of how to use.
//
// The type args are:
//  RequestType: the type of object to create to send over the wire
//  ResponseType: the type of object we expect to receive over the wire
//  ReturnType: the type we will return to the caller
//  RequestTypeParams: type of the params to use for the contructor to the object we send over the
//wre
//
// The params are:
//  myLogger: The logger we write error messages to
//  port: the port to send the request to
//  address: the address to send the request to
//  onErr: the value to return if there is an error sending/receiving data
//  bytesForRequest: the number of bytes to give to the allocator used to build the request
//  processResponse: the function used to process the response to the request
//  args: the arguments to give to the constructor of the request
//

namespace pdb {

template <class RequestType, class ResponseType, class ReturnType, class... RequestTypeParams>
ReturnType simpleRequest(PDBLoggerPtr myLogger,
                         int port,
                         std::string address,
                         ReturnType onErr,
                         size_t bytesForRequest,
                         function<ReturnType(Handle<ResponseType>)> processResponse,
                         RequestTypeParams&&... args);
}

// This is a similar templated function that sends two objects, in sequence and then asks for the
// results.
//
// The type args are:
//  RequestType: the type of object to create to send over the wire
//  SecondRequestType: the second object to create and send over the wirte
//  ResponseType: the type of object we expect to receive over the wire
//  ReturnType: the type we will return to the caller
//  RequestTypeParams: type of the params to use for the contructor to the object we send over the
//wre
//
// The params are:
//  myLogger: The logger we write error messages to
//  port: the port to send the request to
//  address: the address to send the request to
//  onErr: the value to return if there is an error sending/receiving data
//  bytesForRequest: the number of bytes to give to the allocator used to build the request
//  processResponse: the function used to process the response to the request
//  firstRequest: the first request to send over the wire
//  secondRequest: the second request to send over the wire

namespace pdb {

template <class RequestType, class SecondRequestType, class ResponseType, class ReturnType>
ReturnType simpleDoubleRequest(PDBLoggerPtr myLogger,
                               int port,
                               std::string address,
                               ReturnType onErr,
                               size_t bytesForRequest,
                               function<ReturnType(Handle<ResponseType>)> processResponse,
                               Handle<RequestType>& firstRequest,
                               Handle<SecondRequestType>& secondRequest);
}

#endif

#include "SimpleRequest.cc"