TechEmpower.FrameworkBenchmarks/dart/server.dart

import 'dart:async' show Future;
import 'dart:io';
import 'dart:json' as json;
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() {
  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');
  var arguments = parser.parse(new Options().arguments);
  _startServer(
      arguments['address'],
      int.parse(arguments['port']),
      int.parse(arguments['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 'text/html; charset=utf-8' content type.
final _TYPE_HTML = new ContentType('text', 'html', charset: 'utf-8');

/// The 'application/json' content type.
final _TYPE_JSON = new ContentType('application', 'json');

/// The 'text/html; charset=utf-8' content type.
final _TYPE_TEXT = new ContentType('text', 'plain', charset: 'utf-8');

/// 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(address, port, 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((_) {
    HttpServer.bind(address, port).then((server) {
      server.listen((request) {
        switch (request.uri.path) {
          case '/':
            _jsonTest(request);
            break;
          case '/db':
            _dbTest(request);
            break;
          case '/fortunes':
            _fortunesTest(request);
            break;
          case '/update':
            _updateTest(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.add(HttpHeaders.SERVER, 'dart');
  request.response.headers.date = new DateTime.now();
  //
  // Prevent GZIP encoding, because it is disallowed in the rules for these
  // benchmark tests.
  //
  request.response.headers.add(HttpHeaders.CONTENT_ENCODING, '');
  if (type != null) {
    request.response.headers.contentType = type;
  }
  if (response != null) {
    request.response.write(response);
  }
  request.response.close();
}

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

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

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

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

/// Responds with the database query test to the [request].
_dbTest(request) {
  var queries = _parseInt(request.uri.queryParameters['queries']).clamp(1, 500);
  var worlds = new List<World>(queries);
  Future.wait(new List.generate(queries, (index) {
    return _connectionPool.connect().then((connection) {
      return connection.query(
              'SELECT id, randomNumber FROM world WHERE id = @id;',
              { 'id': _RANDOM.nextInt(_WORLD_TABLE_SIZE) + 1 })
          .toList()
          .then((rows) {
            //
            // The benchmark's constraints tell us there is exactly one row.
            //
            var row = rows[0];
            worlds[index] = new World(row[0], row[1]);
          })
          .whenComplete(() { connection.close(); });
    });
  }, growable: false)).then((_) { _sendJson(request, worlds); });
}

/// Responds with the fortunes test to the [request].
_fortunesTest(request) {
  var fortunes = [];
  _connectionPool.connect().then((connection) {
    return connection.query('SELECT id, message FROM fortune;')
        .toList()
        .then((rows) {
          for (var row in rows) {
            fortunes.add(new Fortune(row[0], row[1]));
          }
        })
        .whenComplete(() { connection.close(); });
  }).then((_) {
    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].
_updateTest(request) {
  var queries = _parseInt(request.uri.queryParameters['queries']).clamp(1, 500);
  var worlds = new List<World>(queries);
  Future.wait(new List.generate(queries, (index) {
    return _connectionPool.connect().then((connection) {
      return connection.query(
              'SELECT id, randomNumber FROM world WHERE id = @id;',
              { 'id': _RANDOM.nextInt(_WORLD_TABLE_SIZE) + 1 })
          .toList()
          .then((rows) {
            //
            // The benchmark's constraints tell us there is exactly one row.
            //
            var row = rows[0];
            worlds[index] = new World(row[0], row[1]);
          })
          .whenComplete(() { connection.close(); });
    });
  }, growable: false)).then((_) {
    Future.wait(new List.generate(queries, (int index) {
      var world = worlds[index];
      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(); });
      });
    }, growable: false)).then((_) { _sendJson(request, worlds); });
  });
}

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