Add contacts histogram and directory controller test.

src/main/java/org/whispersystems/textsecuregcm/controllers/DirectoryController.java

@@ -18,7 +18,9 @@ package org.whispersystems.textsecuregcm.controllers;
 
 import com.google.common.base.Optional;
 import com.yammer.dropwizard.auth.Auth;
+import com.yammer.metrics.Metrics;
 import com.yammer.metrics.annotation.Timed;
+import com.yammer.metrics.core.Histogram;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.whispersystems.textsecuregcm.entities.ClientContact;
@@ -46,7 +48,8 @@ import java.util.List;
 @Path("/v1/directory")
 public class DirectoryController {
 
-  private final Logger logger = LoggerFactory.getLogger(DirectoryController.class);
+  private final Logger    logger            = LoggerFactory.getLogger(DirectoryController.class);
+  private final Histogram contactsHistogram = Metrics.newHistogram(DirectoryController.class, "contacts");
 
   private final RateLimiters     rateLimiters;
   private final DirectoryManager directory;
@@ -56,7 +59,7 @@ public class DirectoryController {
     this.rateLimiters = rateLimiters;
   }
 
-  @Timed()
+  @Timed
   @GET
   @Path("/{token}")
   @Produces(MediaType.APPLICATION_JSON)
@@ -77,7 +80,7 @@ public class DirectoryController {
     }
   }
 
-  @Timed()
+  @Timed
   @PUT
   @Path("/tokens")
   @Produces(MediaType.APPLICATION_JSON)
@@ -86,6 +89,7 @@ public class DirectoryController {
       throws RateLimitExceededException
   {
     rateLimiters.getContactsLimiter().validate(account.getNumber(), contacts.getContacts().size());
+    contactsHistogram.update(contacts.getContacts().size());
 
     try {
       List<byte[]> tokens = new LinkedList<>();

src/main/java/org/whispersystems/textsecuregcm/entities/ClientContactTokens.java

@@ -30,4 +30,11 @@ public class ClientContactTokens {
   public List<String> getContacts() {
     return contacts;
   }
+
+  public ClientContactTokens() {}
+
+  public ClientContactTokens(List<String> contacts) {
+    this.contacts = contacts;
+  }
+
 }