Application.java 5.6 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151
  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.*;
  8. import play.core.NamedThreadFactory;
  9. import play.libs.F;
  10. import play.libs.Json;
  11. import play.mvc.*;
  12. import scala.concurrent.ExecutionContext;
  13. import utils.Predicate;
  14. import utils.Predicated;
  15. import views.html.*;
  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. public class Application extends Controller {
  22. private static final int MAX_QUERIES_PER_REQUEST = 20;
  23. private static final int TEST_DATABASE_ROWS = 10000;
  24. private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
  25. private static final int partitionCount = Play.application().configuration().getInt("db.default.partitionCount");
  26. private static final int maxConnections =
  27. partitionCount * Play.application().configuration().getInt("db.default.maxConnectionsPerPartition");
  28. private static final int minConnections =
  29. partitionCount * Play.application().configuration().getInt("db.default.minConnectionsPerPartition");
  30. private static final ThreadPoolExecutor tpe = new ThreadPoolExecutor(minConnections, maxConnections,
  31. 0L, TimeUnit.MILLISECONDS,
  32. new LinkedBlockingQueue<Runnable>(),
  33. new NamedThreadFactory("dbEc"));
  34. private static final ExecutionContext dbEc = ExecutionContexts.fromExecutorService(tpe);
  35. public static Result json() {
  36. final ObjectNode result = OBJECT_MAPPER.createObjectNode();
  37. result.put("message", "Hello World!");
  38. return ok(result);
  39. }
  40. // If the thread-pool used by the database grows too large then our server
  41. // is probably struggling, and we should start dropping requests. Set
  42. // the max size of our queue something above the number of concurrent
  43. // connections that we need to handle.
  44. public static class IsDbAvailable implements Predicate {
  45. @Override
  46. public boolean condition() {
  47. return tpe.getQueue().size() <= 1024;
  48. }
  49. }
  50. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  51. public static F.Promise<Result> db() {
  52. return getRandomWorlds(1).map(new F.Function<List<World>, Result>() {
  53. @Override
  54. public Result apply(List<World> worlds) {
  55. return ok(Json.toJson(worlds.get(0)));
  56. }
  57. });
  58. }
  59. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  60. public static F.Promise<Result> queries(final String queryCountString) {
  61. return getRandomWorlds(queryCount(queryCountString)).map(new F.Function<List<World>, Result>() {
  62. @Override
  63. public Result apply(List<World> worlds) {
  64. return ok(Json.toJson(worlds));
  65. }
  66. });
  67. }
  68. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  69. public static F.Promise<Result> fortunes() {
  70. return F.Promise.promise(new F.Function0<Result>() {
  71. @Override
  72. public Result apply() throws Throwable {
  73. List<Fortune> fortunes = Fortune.findAll();
  74. fortunes.add(new Fortune("Additional fortune added at request time."));
  75. Collections.sort(fortunes, new Comparator<Fortune>() {
  76. @Override
  77. public int compare(Fortune f1, Fortune f2) {
  78. return f1.message.compareTo(f2.message);
  79. }
  80. });
  81. return ok(views.html.fortunes.render(fortunes));
  82. }
  83. }, dbEc);
  84. }
  85. @Predicated(predicate = IsDbAvailable.class, failed = SERVICE_UNAVAILABLE)
  86. public static F.Promise<Result> update(final String queryCountString) {
  87. return getRandomWorlds(queryCount(queryCountString)).map(new F.Function<List<World>, Result>() {
  88. @Override
  89. public Result apply(List<World> worlds) throws Throwable {
  90. Random random = ThreadLocalRandom.current();
  91. for (World world : worlds) {
  92. world.randomNumber = (long) (random.nextInt(10000) + 1);
  93. }
  94. worlds = World.save(worlds);
  95. return ok(Json.toJson(worlds));
  96. }
  97. });
  98. }
  99. public static Result plainText() {
  100. return ok("Hello, World!");
  101. }
  102. private static int queryCount(String queryCountString) {
  103. int queryCount;
  104. try {
  105. queryCount = Integer.parseInt(queryCountString, 10);
  106. } catch (NumberFormatException e) {
  107. queryCount = 1;
  108. }
  109. if (queryCount < 1) {
  110. queryCount = 1;
  111. } else if (queryCount > 500) {
  112. queryCount = 500;
  113. }
  114. return queryCount;
  115. }
  116. private static F.Promise<List<World>> getRandomWorlds(final int n) {
  117. return F.Promise.promise(new F.Function0<List<World>>() {
  118. @Override
  119. public List<World> apply() throws Throwable {
  120. Random random = ThreadLocalRandom.current();
  121. List<World> worlds = new ArrayList<World>(n);
  122. for (int i = 0; i < n; ++i) {
  123. long randomId = random.nextInt(TEST_DATABASE_ROWS) + 1;
  124. World world = World.findById(randomId);
  125. worlds.add(world);
  126. }
  127. return worlds;
  128. }
  129. }, dbEc);
  130. }
  131. }