Application.java 5.2 KB

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  1. package controllers;
  2. import akka.dispatch.ExecutionContexts;
  3. import models.Fortune;
  4. import models.World;
  5. import play.Play;
  6. import play.core.NamedThreadFactory;
  7. import play.libs.F;
  8. import play.libs.Json;
  9. import play.mvc.Controller;
  10. import play.mvc.Result;
  11. import play.mvc.With;
  12. import scala.concurrent.ExecutionContext;
  13. import utils.Headers;
  14. import utils.Predicate;
  15. import utils.Predicated;
  16. import java.util.*;
  17. import java.util.concurrent.LinkedBlockingQueue;
  18. import java.util.concurrent.ThreadLocalRandom;
  19. import java.util.concurrent.ThreadPoolExecutor;
  20. import java.util.concurrent.TimeUnit;
  21. @With(Headers.class)
  22. public class Application extends Controller {
  23. private static final int TEST_DATABASE_ROWS = 10000;
  24. private static final int partitionCount = Play.application().configuration().getInt("db.default.partitionCount");
  25. private static final int maxConnections =
  26. partitionCount * Play.application().configuration().getInt("db.default.maxConnectionsPerPartition");
  27. private static final int minConnections =
  28. partitionCount * Play.application().configuration().getInt("db.default.minConnectionsPerPartition");
  29. private static final ThreadPoolExecutor tpe = new ThreadPoolExecutor(minConnections, maxConnections,
  30. 0L, TimeUnit.MILLISECONDS,
  31. new LinkedBlockingQueue<Runnable>(),
  32. new NamedThreadFactory("dbEc"));
  33. private static final ExecutionContext dbEc = ExecutionContexts.fromExecutorService(tpe);
  34. // If the thread-pool used by the database grows too large then our server
  35. // is probably struggling, and we should start dropping requests. Set
  36. // the max size of our queue something above the number of concurrent
  37. // connections that we need to handle.
  38. public static class IsDbAvailable implements Predicate {
  39. @Override
  40. public boolean condition() {
  41. return tpe.getQueue().size() <= 1024;
  42. }
  43. }
  44. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  45. public static F.Promise<Result> db() {
  46. return getRandomWorlds(1).map(new F.Function<List<World>, Result>() {
  47. @Override
  48. public Result apply(List<World> worlds) {
  49. return ok(Json.toJson(worlds.get(0)));
  50. }
  51. });
  52. }
  53. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  54. public static F.Promise<Result> queries(final String queryCountString) {
  55. return getRandomWorlds(queryCount(queryCountString)).map(new F.Function<List<World>, Result>() {
  56. @Override
  57. public Result apply(List<World> worlds) {
  58. return ok(Json.toJson(worlds));
  59. }
  60. });
  61. }
  62. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  63. public static F.Promise<Result> fortunes() {
  64. return F.Promise.promise(new F.Function0<Result>() {
  65. @Override
  66. public Result apply() throws Throwable {
  67. List<Fortune> fortunes = Fortune.find.all();
  68. fortunes.add(new Fortune("Additional fortune added at request time."));
  69. Collections.sort(fortunes, new Comparator<Fortune>() {
  70. @Override
  71. public int compare(Fortune f1, Fortune f2) {
  72. return f1.message.compareTo(f2.message);
  73. }
  74. });
  75. return ok(views.html.fortunes.render(fortunes));
  76. }
  77. }, dbEc);
  78. }
  79. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  80. public static F.Promise<Result> update(final String queryCountString) {
  81. return getRandomWorlds(queryCount(queryCountString)).map(new F.Function<List<World>, Result>() {
  82. @Override
  83. public Result apply(List<World> worlds) throws Throwable {
  84. Random random = ThreadLocalRandom.current();
  85. for (World world : worlds) {
  86. world.randomNumber = (long) (random.nextInt(10000) + 1);
  87. }
  88. List<World> updatedWorlds = World.save(worlds);
  89. return ok(Json.toJson(updatedWorlds));
  90. }
  91. }, dbEc);
  92. }
  93. private static int queryCount(String queryCountString) {
  94. int queryCount;
  95. try {
  96. queryCount = Integer.parseInt(queryCountString, 10);
  97. } catch (NumberFormatException e) {
  98. queryCount = 1;
  99. }
  100. if (queryCount < 1) {
  101. queryCount = 1;
  102. } else if (queryCount > 500) {
  103. queryCount = 500;
  104. }
  105. return queryCount;
  106. }
  107. private static F.Promise<List<World>> getRandomWorlds(final int n) {
  108. return F.Promise.promise(new F.Function0<List<World>>() {
  109. @Override
  110. public List<World> apply() {
  111. Random random = ThreadLocalRandom.current();
  112. List<World> worlds = new ArrayList<World>(n);
  113. for (int i = 0; i < n; ++i) {
  114. long randomId = random.nextInt(TEST_DATABASE_ROWS) + 1;
  115. World world = World.find.byId(randomId);
  116. worlds.add(world);
  117. }
  118. return worlds;
  119. }
  120. }, dbEc);
  121. }
  122. }