177 lines
4.5 KiB
JavaScript
177 lines
4.5 KiB
JavaScript
/*
|
|
* Copyright 2018 Google LLC.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
if(process.env.DISABLE_PROFILER) {
|
|
console.log("Profiler disabled.")
|
|
}
|
|
else {
|
|
console.log("Profiler enabled.")
|
|
require('@google-cloud/profiler').start({
|
|
serviceContext: {
|
|
service: 'currencyservice',
|
|
version: '1.0.0'
|
|
}
|
|
});
|
|
}
|
|
|
|
|
|
if(process.env.DISABLE_TRACING) {
|
|
console.log("Tracing disabled.")
|
|
}
|
|
else {
|
|
console.log("Tracing enabled.")
|
|
require('@google-cloud/trace-agent').start();
|
|
}
|
|
|
|
if(process.env.DISABLE_DEBUGGER) {
|
|
console.log("Debugger disabled.")
|
|
}
|
|
else {
|
|
console.log("Debugger enabled.")
|
|
require('@google-cloud/debug-agent').start({
|
|
serviceContext: {
|
|
service: 'currencyservice',
|
|
version: 'VERSION'
|
|
}
|
|
});
|
|
}
|
|
|
|
const path = require('path');
|
|
const grpc = require('grpc');
|
|
const pino = require('pino');
|
|
const protoLoader = require('@grpc/proto-loader');
|
|
|
|
const MAIN_PROTO_PATH = path.join(__dirname, './proto/demo.proto');
|
|
const HEALTH_PROTO_PATH = path.join(__dirname, './proto/grpc/health/v1/health.proto');
|
|
|
|
const PORT = process.env.PORT;
|
|
|
|
const shopProto = _loadProto(MAIN_PROTO_PATH).hipstershop;
|
|
const healthProto = _loadProto(HEALTH_PROTO_PATH).grpc.health.v1;
|
|
|
|
const logger = pino({
|
|
name: 'currencyservice-server',
|
|
messageKey: 'message',
|
|
changeLevelName: 'severity',
|
|
useLevelLabels: true
|
|
});
|
|
|
|
/**
|
|
* Helper function that loads a protobuf file.
|
|
*/
|
|
function _loadProto (path) {
|
|
const packageDefinition = protoLoader.loadSync(
|
|
path,
|
|
{
|
|
keepCase: true,
|
|
longs: String,
|
|
enums: String,
|
|
defaults: true,
|
|
oneofs: true
|
|
}
|
|
);
|
|
return grpc.loadPackageDefinition(packageDefinition);
|
|
}
|
|
|
|
/**
|
|
* Helper function that gets currency data from a stored JSON file
|
|
* Uses public data from European Central Bank
|
|
*/
|
|
function _getCurrencyData (callback) {
|
|
const data = require('./data/currency_conversion.json');
|
|
callback(data);
|
|
}
|
|
|
|
/**
|
|
* Helper function that handles decimal/fractional carrying
|
|
*/
|
|
function _carry (amount) {
|
|
const fractionSize = Math.pow(10, 9);
|
|
amount.nanos += (amount.units % 1) * fractionSize;
|
|
amount.units = Math.floor(amount.units) + Math.floor(amount.nanos / fractionSize);
|
|
amount.nanos = amount.nanos % fractionSize;
|
|
return amount;
|
|
}
|
|
|
|
/**
|
|
* Lists the supported currencies
|
|
*/
|
|
function getSupportedCurrencies (call, callback) {
|
|
logger.info('Getting supported currencies...');
|
|
_getCurrencyData((data) => {
|
|
callback(null, {currency_codes: Object.keys(data)});
|
|
});
|
|
}
|
|
|
|
/**
|
|
* Converts between currencies
|
|
*/
|
|
function convert (call, callback) {
|
|
logger.info('received conversion request');
|
|
try {
|
|
_getCurrencyData((data) => {
|
|
const request = call.request;
|
|
|
|
// Convert: from_currency --> EUR
|
|
const from = request.from;
|
|
const euros = _carry({
|
|
units: from.units / data[from.currency_code],
|
|
nanos: from.nanos / data[from.currency_code]
|
|
});
|
|
|
|
euros.nanos = Math.round(euros.nanos);
|
|
|
|
// Convert: EUR --> to_currency
|
|
const result = _carry({
|
|
units: euros.units * data[request.to_code],
|
|
nanos: euros.nanos * data[request.to_code]
|
|
});
|
|
|
|
result.units = Math.floor(result.units);
|
|
result.nanos = Math.floor(result.nanos);
|
|
result.currency_code = request.to_code;
|
|
|
|
logger.info(`conversion request successful`);
|
|
callback(null, result);
|
|
});
|
|
} catch (err) {
|
|
logger.error(`conversion request failed: ${err}`);
|
|
callback(err.message);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Endpoint for health checks
|
|
*/
|
|
function check (call, callback) {
|
|
callback(null, { status: 'SERVING' });
|
|
}
|
|
|
|
/**
|
|
* Starts an RPC server that receives requests for the
|
|
* CurrencyConverter service at the sample server port
|
|
*/
|
|
function main () {
|
|
logger.info(`Starting gRPC server on port ${PORT}...`);
|
|
const server = new grpc.Server();
|
|
server.addService(shopProto.CurrencyService.service, {getSupportedCurrencies, convert});
|
|
server.addService(healthProto.Health.service, {check});
|
|
server.bind(`0.0.0.0:${PORT}`, grpc.ServerCredentials.createInsecure());
|
|
server.start();
|
|
}
|
|
|
|
main();
|