Line data    Source code

       1             : // Copyright (C) 2014 The Android Open Source Project
       2             : //
       3             : // Licensed under the Apache License, Version 2.0 (the "License");
       4             : // you may not use this file except in compliance with the License.
       5             : // You may obtain a copy of the License at
       6             : //
       7             : // http://www.apache.org/licenses/LICENSE-2.0
       8             : //
       9             : // Unless required by applicable law or agreed to in writing, software
      10             : // distributed under the License is distributed on an "AS IS" BASIS,
      11             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             : // See the License for the specific language governing permissions and
      13             : // limitations under the License.
      14             : 
      15             : package com.google.gerrit.index.query;
      16             : 
      17             : import com.google.auto.value.AutoValue;
      18             : import com.google.common.collect.ImmutableList;
      19             : import com.google.gerrit.common.Nullable;
      20             : import java.util.List;
      21             : 
      22             : /** Results of a query over entities. */
      23             : @AutoValue
      24         151 : public abstract class QueryResult<T> {
      25             :   public static <T> QueryResult<T> create(
      26             :       @Nullable String query, Predicate<T> predicate, int limit, List<T> entities) {
      27             :     boolean more;
      28         151 :     if (entities.size() > limit) {
      29          17 :       more = true;
      30          17 :       entities = entities.subList(0, limit);
      31             :     } else {
      32         151 :       more = false;
      33             :     }
      34         151 :     return new AutoValue_QueryResult<>(query, predicate, ImmutableList.copyOf(entities), more);
      35             :   }
      36             : 
      37             :   /** Returns the original query string, or null if the query was created programmatically. */
      38             :   @Nullable
      39             :   public abstract String query();
      40             : 
      41             :   /** Returns the predicate after all rewriting and other modification by the query subsystem. */
      42             :   public abstract Predicate<T> predicate();
      43             : 
      44             :   /** Returns the query results. */
      45             :   public abstract ImmutableList<T> entities();
      46             : 
      47             :   /**
      48             :    * Returns whether the query could be retried with a higher start/limit to produce more results.
      49             :    * Never true if {@link #entities()} is empty.
      50             :    */
      51             :   public abstract boolean more();
      52             : }