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/*
*
* Copyright 2015, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
'use strict';
var grpc = require('..');
var math = grpc.load(__dirname + '/math.proto').math;
/**
* 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;
// Unary + is explicit coersion to integer
if (+req.divisor === 0) {
cb(new Error('cannot divide by zero'));
} else {
cb(null, {
quotient: req.dividend / req.divisor,
remainder: req.dividend % req.divisor
});
}
}
/**
* 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.limit; i++) {
stream.write({num: current});
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.num);
});
call.on('end', function() {
cb(null, {num: sum});
});
}
function mathDivMany(stream) {
stream.on('data', function(div_args) {
if (+div_args.divisor === 0) {
stream.emit('error', new Error('cannot divide by zero'));
} else {
stream.write({
quotient: div_args.dividend / div_args.divisor,
remainder: div_args.dividend % div_args.divisor
});
}
});
stream.on('end', function() {
stream.end();
});
}
var server = new grpc.Server();
server.addProtoService(math.Math.service, {
div: mathDiv,
fib: mathFib,
sum: mathSum,
divMany: mathDivMany
});
if (require.main === module) {
server.bind('0.0.0.0:50051');
server.start();
}
/**
* See docs for server
*/
module.exports = server;
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