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/*
*
* Copyright 2015 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
'use strict';
var grpc = require('../..');
var grpcMath = require('./math_grpc_pb');
var math = require('./math_pb');
/**
* Server function for division. Provides the /Math/DivMany and /Math/Div
* functions (Div is just DivMany with only one stream element). For each
* DivArgs parameter, responds with a DivReply with the results of the division
* @param {Object} call The object containing request and cancellation info
* @param {function(Error, *)} cb Response callback
*/
function mathDiv(call, cb) {
var req = call.request;
var divisor = req.getDivisor();
var dividend = req.getDividend();
// Unary + is explicit coersion to integer
if (req.getDivisor() === 0) {
cb(new Error('cannot divide by zero'));
} else {
var response = new math.DivReply();
response.setQuotient(Math.floor(dividend / divisor));
response.setRemainder(dividend % divisor);
cb(null, response);
}
}
/**
* Server function for Fibonacci numbers. Provides the /Math/Fib function. Reads
* a single parameter that indicates the number of responses, and then responds
* with a stream of that many Fibonacci numbers.
* @param {stream} stream The stream for sending responses.
*/
function mathFib(stream) {
// Here, call is a standard writable Node object Stream
var previous = 0, current = 1;
for (var i = 0; i < stream.request.getLimit(); i++) {
var response = new math.Num();
response.setNum(current);
stream.write(response);
var temp = current;
current += previous;
previous = temp;
}
stream.end();
}
/**
* Server function for summation. Provides the /Math/Sum function. Reads a
* stream of number parameters, then responds with their sum.
* @param {stream} call The stream of arguments.
* @param {function(Error, *)} cb Response callback
*/
function mathSum(call, cb) {
// Here, call is a standard readable Node object Stream
var sum = 0;
call.on('data', function(data) {
sum += data.getNum();
});
call.on('end', function() {
var response = new math.Num();
response.setNum(sum);
cb(null, response);
});
}
function mathDivMany(stream) {
stream.on('data', function(div_args) {
var divisor = div_args.getDivisor();
var dividend = div_args.getDividend();
if (divisor === 0) {
stream.emit('error', new Error('cannot divide by zero'));
} else {
var response = new math.DivReply();
response.setQuotient(Math.floor(dividend / divisor));
response.setRemainder(dividend % divisor);
stream.write(response);
}
});
stream.on('end', function() {
stream.end();
});
}
function getMathServer() {
var server = new grpc.Server();
server.addService(grpcMath.MathService, {
div: mathDiv,
fib: mathFib,
sum: mathSum,
divMany: mathDivMany
});
return server;
}
if (require.main === module) {
var server = getMathServer();
server.bind('0.0.0.0:50051', grpc.ServerCredentials.createInsecure());
server.start();
}
/**
* See docs for server
*/
module.exports = getMathServer;
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