TechEmpower.FrameworkBenchmarks/frameworks/Dart/dart/server.dart

import 'dart:async' show Future;
import 'dart:convert';
import 'dart:io';
import 'dart:isolate';
import 'dart:math' show Random;
import 'package:args/args.dart' show ArgParser;
import 'package:mustache/mustache.dart' as mustache;
import 'package:postgresql/postgresql.dart' as pg;
import 'package:postgresql/postgresql_pool.dart' as pgpool;
import 'package:yaml/yaml.dart' as yaml;

/// Starts a new HTTP server that implements the tests to be benchmarked.  The
/// address and port for incoming connections is configurable via command line
/// arguments, as is the number of database connections to be maintained in the
/// connection pool.
main(List<String> args) {
  var parser = new ArgParser();
  parser.addOption('address', abbr: 'a', defaultsTo: '0.0.0.0');
  parser.addOption('port', abbr: 'p', defaultsTo: '8080');
  parser.addOption('dbconnections', abbr: 'd', defaultsTo: '256');
  parser.addOption('isolates', abbr: 'i', defaultsTo: '1');
  var arguments = parser.parse(args);
  var isolates = int.parse(arguments['isolates']);
  var dbConnections = int.parse(arguments['dbconnections']) ~/ isolates;
  ServerSocket.bind(arguments['address'], int.parse(arguments['port']))
      .then((server) {
        var ref = server.reference;
        for (int i = 1; i < isolates; i++) {
          Isolate.spawn(startInIsolate, [ref, dbConnections]);
        }
        _startServer(server, dbConnections);
      });
}

void startInIsolate(args) {
  var ref = args[0];
  var dbConnections = args[1];
  ref.create().then((server) {
    _startServer(server, dbConnections);
  });
}

/// The entity used in the database query and update tests.
class World {
  int id;

  int randomnumber;

  World(this.id, this.randomnumber);

  toJson() => { 'id': id, 'randomNumber': randomnumber };
}

/// The entity used in the fortunes test.
class Fortune implements Comparable<Fortune> {
  int id;
  String message;

  Fortune(this.id, this.message);

  compareTo(Fortune other) => message.compareTo(other.message);
}

/// The number of rows in the world entity table.
const _WORLD_TABLE_SIZE = 10000;

/// A random number generator.
final _RANDOM = new Random();

/// The PostgreSQL connection pool used by all the tests that require database
/// connectivity.
var _connectionPool;

/// The mustache template which is rendered in the fortunes test.
var _fortunesTemplate;

/// Starts a benchmark server, which listens for connections from
/// '[address] : [port]' and maintains [dbConnections] connections to the
/// database.
_startServer(serverSocket, dbConnections) {
  Future.wait([
    new File('postgresql.yaml').readAsString().then((config) {
      _connectionPool = new pgpool.Pool(
          new pg.Settings.fromMap(yaml.loadYaml(config)).toUri(),
          min: dbConnections,
          max: dbConnections);
      return _connectionPool.start();
    }),
    new File('fortunes.mustache').readAsString().then((template) {
      _fortunesTemplate = mustache.parse(template);
    })
  ]).then((_) {
    var server = new HttpServer.listenOn(serverSocket);
    server.defaultResponseHeaders.clear();
    server.serverHeader = 'dart';
    server.listen((request) {
      switch (request.uri.path) {
        case '/json':
          _jsonTest(request);
          break;
        case '/db':
          _dbTest(request);
          break;
        case '/queries':
          _queriesTest(request);
          break;
        case '/fortunes':
          _fortunesTest(request);
          break;
        case '/updates':
          _updatesTest(request);
          break;
        case '/plaintext':
          _plaintextTest(request);
          break;
        default:
          _sendResponse(request, HttpStatus.NOT_FOUND);
          break;
      }
    });
  });
}

/// Returns the given [text] parsed as a base 10 integer.  If the text is null
/// or is an otherwise invalid representation of a base 10 integer, zero is
/// returned.
_parseInt(text) =>
    (text == null) ? 0 : int.parse(text, radix: 10, onError: ((_) => 0));

/// Completes the given [request] by writing the [response] with the given
/// [statusCode] and [type].
_sendResponse(request, statusCode, [ type, response ]) {
  request.response.statusCode = statusCode;
  request.response.headers.date = new DateTime.now();
  if (type != null) {
    request.response.headers.contentType = type;
  }
  if (response != null) {
    var data = UTF8.encode(response);
    request.response.contentLength = data.length;
    request.response.add(data);
  } else {
    request.response.contentLength = 0;
  }
  request.response.close();
}

/// Completes the given [request] by writing the [response] as HTML.
_sendHtml(request, response) {
  _sendResponse(request, HttpStatus.OK, ContentType.HTML, response);
}

/// Completes the given [request] by writing the [response] as JSON.
_sendJson(request, response) {
  _sendResponse(
      request, HttpStatus.OK, ContentType.JSON, JSON.encode(response));
}

/// Completes the given [request] by writing the [response] as plain text.
_sendText(request, response) {
  _sendResponse(request, HttpStatus.OK, ContentType.TEXT, response);
}

/// Responds with the JSON test to the [request].
_jsonTest(request) {
  _sendJson(request, { 'message': 'Hello, World!' });
}

_queryRandom() {
  return _connectionPool.connect()
      .then((connection) {
        return connection.query(
            'SELECT id, randomnumber FROM world WHERE id = @id;',
            { 'id': _RANDOM.nextInt(_WORLD_TABLE_SIZE) + 1 })
            //
            // The benchmark's constraints tell us there is exactly one row.
            //
            .single
            .then((row) => new World(row[0], row[1]))
            .whenComplete(() { connection.close(); });
      });
}

/// Responds with the database query test to the [request].
_dbTest(request) {
  _queryRandom().then((response) => _sendJson(request, response));
}

/// Responds with the database queries test to the [request].
_queriesTest(request) {
  var queries = _parseInt(request.uri.queryParameters['queries']).clamp(1, 500);
  Future.wait(new List.generate(queries,
                                (_) => _queryRandom(),
                                growable: false))
      .then((response) => _sendJson(request, response));
}

/// Responds with the fortunes test to the [request].
_fortunesTest(request) {
  _connectionPool.connect().then((connection) {
    return connection.query('SELECT id, message FROM fortune;')
        .map((row) => new Fortune(row[0], row[1]))
        .toList()
        .whenComplete(() { connection.close(); });
  }).then((fortunes) {
    fortunes.add(new Fortune(0, 'Additional fortune added at request time.'));
    fortunes.sort();
    _sendHtml(request, _fortunesTemplate.renderString({
      'fortunes': fortunes.map((fortune) => {
              'id': fortune.id, 'message': fortune.message
          }).toList()
    }));
  });
}

/// Responds with the updates test to the [request].
_updatesTest(request) {
  var queries = _parseInt(request.uri.queryParameters['queries']).clamp(1, 500);
  Future.wait(new List.generate(queries, (_) {
    return _queryRandom()
        .then((world) {
          world.randomnumber = _RANDOM.nextInt(_WORLD_TABLE_SIZE) + 1;
          return _connectionPool.connect().then((connection) {
            return connection.execute(
                'UPDATE world SET randomnumber = @randomnumber WHERE id = @id;',
                { 'randomnumber': world.randomnumber, 'id': world.id })
                .whenComplete(() { connection.close(); });
          }).then((_) => world);
        });
  }, growable: false))
      .then((worlds) => _sendJson(request, worlds));
}

/// Responds with the plaintext test to the [request].
_plaintextTest(request) {
  _sendText(request, 'Hello, World!');
}