Remove unused CurrentUser#cacheKey method

Change-Id: If7ccfd9a418a379c677a7150fd14a7fc2d497cd5

java/com/google/gerrit/server/AnonymousUser.java

@@ -26,12 +26,6 @@ public class AnonymousUser extends CurrentUser {
     return new ListGroupMembership(Collections.singleton(SystemGroupBackend.ANONYMOUS_USERS));
   }
 
-  @Override
-  public Object getCacheKey() {
-    // Treat all anonymous users as a single user
-    return "anonymous";
-  }
-
   @Override
   public String toString() {
     return "ANONYMOUS";

java/com/google/gerrit/server/CurrentUser.java

@@ -90,12 +90,6 @@ public abstract class CurrentUser {
    */
   public abstract GroupMembership getEffectiveGroups();
 
-  /**
-   * Returns a unique identifier for this user that is intended to be used as a cache key. Returned
-   * object should to implement {@code equals()} and {@code hashCode()} for effective caching.
-   */
-  public abstract Object getCacheKey();
-
   /** Unique name of the user on this server, if one has been assigned. */
   public Optional<String> getUserName() {
     return Optional.empty();

java/com/google/gerrit/server/IdentifiedUser.java

@@ -390,11 +390,6 @@ public class IdentifiedUser extends CurrentUser {
     return effectiveGroups;
   }
 
-  @Override
-  public Object getCacheKey() {
-    return getAccountId();
-  }
-
   public PersonIdent newRefLogIdent() {
     return newRefLogIdent(new Date(), TimeZone.getDefault());
   }

java/com/google/gerrit/server/InternalUser.java

@@ -35,11 +35,6 @@ public class InternalUser extends CurrentUser {
     return GroupMembership.EMPTY;
   }
 
-  @Override
-  public String getCacheKey() {
-    return "internal";
-  }
-
   @Override
   public boolean isInternalUser() {
     return true;

java/com/google/gerrit/server/PeerDaemonUser.java

@@ -40,11 +40,6 @@ public class PeerDaemonUser extends CurrentUser {
     return GroupMembership.EMPTY;
   }
 
-  @Override
-  public Object getCacheKey() {
-    return getRemoteAddress();
-  }
-
   public SocketAddress getRemoteAddress() {
     return peer;
   }

java/com/google/gerrit/server/query/change/SingleGroupUser.java

@@ -36,9 +36,4 @@ public final class SingleGroupUser extends CurrentUser {
   public GroupMembership getEffectiveGroups() {
     return groups;
   }
-
-  @Override
-  public Object getCacheKey() {
-    return groups.getKnownGroups();
-  }
 }

javatests/com/google/gerrit/server/extensions/webui/UiActionsTest.java

@@ -100,11 +100,6 @@ public class UiActionsTest {
           throw new UnsupportedOperationException("not implemented");
         }
 
-        @Override
-        public Object getCacheKey() {
-          return new Object();
-        }
-
         @Override
         public boolean isIdentifiedUser() {
           return true;

javatests/com/google/gerrit/server/permissions/RefControlTest.java

@@ -1197,11 +1197,6 @@ public class RefControlTest {
       return groups;
     }
 
-    @Override
-    public Object getCacheKey() {
-      return new Object();
-    }
-
     @Override
     public Optional<String> getUserName() {
       return Optional.ofNullable(username);