使用 Node.js 的 gRPC 更新 Redis 数据

需要三个东西：设定文件、服务器程序、客户端程序。

配置文件

redis_update.proto
与此文件相同
在Python的gRPC中使用Redis更新数据 (更新)

服务器程序

#! /usr/bin/node
// ---------------------------------------------------------------
//  redis_update_server.js
//
//                  Feb/09/2020
// ---------------------------------------------------------------
var PROTO_PATH = 'redis_update.proto'

var grpc = require('grpc')

var protoLoader = require('@grpc/proto-loader')
var packageDefinition = protoLoader.loadSync(
    PROTO_PATH,
    {keepCase: true,
     longs: String,
     enums: String,
     defaults: true,
     oneofs: true
    });
var redis_update_proto = grpc.loadPackageDefinition(packageDefinition).redis_update

// ---------------------------------------------------------------
function get_current_date_proc()
{
    const today = new Date ()
    var ddx = (1900 + today.getYear ()) + "-" + (today.getMonth () +1)
    ddx += "-" + today.getDate ()

    return ddx
}

// ---------------------------------------------------------------
function redis_update_proc(key_in,population_in)
{
    const redis = require ("redis")
    const client = redis.createClient (6379,'localhost')

    client.on("error", function (err)
        {
        console.log("Redis connection error to "
            + client.host + ":" + client.port + " - " + err)
        })

client.get (key_in, function (err, reply)
    {
    if (err)
        {
        console.log("Get error: " + err)
            }
     else if (reply != null)
        {
        var json_str = reply

        var unit_aa = JSON.parse (json_str)

        unit_aa.population = population_in
        unit_aa.date_mod =  get_current_date_proc ()
        var json_out = JSON.stringify (unit_aa)

        console.log (json_out)

        client.set (key_in,json_out, redis.print)
        client.quit()
        }
    })

}

// ---------------------------------------------------------------
function RedisUpdate(call, callback) {
    console.error("*** RedisUpdate ***")
    const key_in = call.request.key
    const population_in = call.request.population
    const str_out = 'RedisUpdate ' + call.request.key
    console.error(str_out)
    redis_update_proc(key_in,population_in)
    callback(null, {key: call.request.key});
}

// ---------------------------------------------------------------
function main() {
    var server = new grpc.Server()
    server.addService(redis_update_proto.Greeter.service, {RedisUpdate: RedisUpdate })
    server.bind('0.0.0.0:50051', grpc.ServerCredentials.createInsecure())
    server.start()
}

// ---------------------------------------------------------------
main()
// ---------------------------------------------------------------

客户端程序

#! /usr/bin/node
// ---------------------------------------------------------------
//  redis_update_client.js
//
//                      Feb/09/2020
// ---------------------------------------------------------------
var PROTO_PATH = 'redis_update.proto'

var grpc = require('grpc')
var protoLoader = require('@grpc/proto-loader')
var packageDefinition = protoLoader.loadSync(
    PROTO_PATH,
    {keepCase: true,
     longs: String,
     enums: String,
     defaults: true,
     oneofs: true
    })

var redis_update_proto = grpc.loadPackageDefinition(packageDefinition).redis_update

// ---------------------------------------------------------------
function main() {
    var client = new redis_update_proto.Greeter('localhost:50051',
                                       grpc.credentials.createInsecure())

    var key_in = process.argv[2]
    var population_in = process.argv[3]
    client.RedisUpdate({key: key_in,population: population_in},
        function(err, response) {
    console.log('key:', response.key)
    })

}

// ---------------------------------------------------------------
main()
// ---------------------------------------------------------------

启动服务器程序

export NODE_PATH=/usr/lib/node_modules
./redis_update_server.js

执行客户端程序

$ export NODE_PATH=/usr/lib/node_modules
$ ./redis_update_client.js t1857 8234500
key: t1857