Application.java 5.8 KB

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  1. package controllers;
  2. import akka.dispatch.ExecutionContexts;
  3. import com.fasterxml.jackson.databind.ObjectMapper;
  4. import com.fasterxml.jackson.databind.node.ObjectNode;
  5. import models.Fortune;
  6. import models.World;
  7. import play.Play;
  8. import play.core.NamedThreadFactory;
  9. import play.libs.F;
  10. import play.libs.Json;
  11. import play.mvc.Controller;
  12. import play.mvc.Result;
  13. import play.mvc.With;
  14. import scala.concurrent.ExecutionContext;
  15. import utils.Headers;
  16. import utils.Predicate;
  17. import utils.Predicated;
  18. import java.util.*;
  19. import java.util.concurrent.LinkedBlockingQueue;
  20. import java.util.concurrent.ThreadLocalRandom;
  21. import java.util.concurrent.ThreadPoolExecutor;
  22. import java.util.concurrent.TimeUnit;
  23. @With(Headers.class)
  24. public class Application extends Controller {
  25. private static final int TEST_DATABASE_ROWS = 10000;
  26. private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
  27. private static final int partitionCount = Play.application().configuration().getInt("db.default.partitionCount");
  28. private static final int maxConnections =
  29. partitionCount * Play.application().configuration().getInt("db.default.maxConnectionsPerPartition");
  30. private static final int minConnections =
  31. partitionCount * Play.application().configuration().getInt("db.default.minConnectionsPerPartition");
  32. private static final ThreadPoolExecutor tpe = new ThreadPoolExecutor(minConnections, maxConnections,
  33. 0L, TimeUnit.MILLISECONDS,
  34. new LinkedBlockingQueue<Runnable>(),
  35. new NamedThreadFactory("dbEc"));
  36. private static final ExecutionContext dbEc = ExecutionContexts.fromExecutorService(tpe);
  37. public static Result json() {
  38. final ObjectNode result = OBJECT_MAPPER.createObjectNode();
  39. result.put("message", "Hello World!");
  40. return ok(result);
  41. }
  42. // If the thread-pool used by the database grows too large then our server
  43. // is probably struggling, and we should start dropping requests. Set
  44. // the max size of our queue something above the number of concurrent
  45. // connections that we need to handle.
  46. public static class IsDbAvailable implements Predicate {
  47. @Override
  48. public boolean condition() {
  49. return tpe.getQueue().size() <= 1024;
  50. }
  51. }
  52. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  53. public static F.Promise<Result> db() {
  54. return getRandomWorlds(1).map(new F.Function<List<World>, Result>() {
  55. @Override
  56. public Result apply(List<World> worlds) {
  57. return ok(Json.toJson(worlds.get(0)));
  58. }
  59. });
  60. }
  61. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  62. public static F.Promise<Result> queries(final String queryCountString) {
  63. return getRandomWorlds(queryCount(queryCountString)).map(new F.Function<List<World>, Result>() {
  64. @Override
  65. public Result apply(List<World> worlds) {
  66. return ok(Json.toJson(worlds));
  67. }
  68. });
  69. }
  70. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  71. public static F.Promise<Result> fortunes() {
  72. return F.Promise.promise(new F.Function0<Result>() {
  73. @Override
  74. public Result apply() throws Throwable {
  75. List<Fortune> fortunes = Fortune.findAll();
  76. fortunes.add(new Fortune("Additional fortune added at request time."));
  77. Collections.sort(fortunes, new Comparator<Fortune>() {
  78. @Override
  79. public int compare(Fortune f1, Fortune f2) {
  80. return f1.message.compareTo(f2.message);
  81. }
  82. });
  83. return ok(views.html.fortunes.render(fortunes));
  84. }
  85. }, dbEc);
  86. }
  87. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  88. public static F.Promise<Result> update(final String queryCountString) {
  89. return getRandomWorlds(queryCount(queryCountString)).flatMap(new F.Function<List<World>, F.Promise<Result>>() {
  90. @Override
  91. public F.Promise<Result> apply(List<World> worlds) throws Throwable {
  92. return updateWorlds(worlds);
  93. }
  94. });
  95. }
  96. private static int queryCount(String queryCountString) {
  97. int queryCount;
  98. try {
  99. queryCount = Integer.parseInt(queryCountString, 10);
  100. } catch (NumberFormatException e) {
  101. queryCount = 1;
  102. }
  103. if (queryCount < 1) {
  104. queryCount = 1;
  105. } else if (queryCount > 500) {
  106. queryCount = 500;
  107. }
  108. return queryCount;
  109. }
  110. private static F.Promise<List<World>> getRandomWorlds(final int n) {
  111. return F.Promise.promise(new F.Function0<List<World>>() {
  112. @Override
  113. public List<World> apply() throws Throwable {
  114. Random random = ThreadLocalRandom.current();
  115. List<World> worlds = new ArrayList<World>(n);
  116. for (int i = 0; i < n; ++i) {
  117. long randomId = random.nextInt(TEST_DATABASE_ROWS) + 1;
  118. World world = World.findById(randomId);
  119. worlds.add(world);
  120. }
  121. return worlds;
  122. }
  123. }, dbEc);
  124. }
  125. private static F.Promise<Result> updateWorlds(final List<World> worlds) {
  126. return F.Promise.promise(new F.Function0<Result>() {
  127. @Override
  128. public Result apply() throws Throwable {
  129. Random random = ThreadLocalRandom.current();
  130. for (World world : worlds) {
  131. world.randomNumber = (long) (random.nextInt(10000) + 1);
  132. }
  133. List<World> updatedWorlds = World.save(worlds);
  134. return ok(Json.toJson(updatedWorlds));
  135. }
  136. }, dbEc);
  137. }
  138. }