java/src/main/com/google/appengine/api/datastore/WrappedQueryResultCloudDatastoreV1.java

   1 package com.google.appengine.api.datastore;
   2
   3 import static com.google.common.base.Preconditions.checkState;
   4
   5 import com.google.appengine.api.datastore.BaseQueryResultsSource.WrappedQueryResult;
   6 import com.google.common.collect.ImmutableList;
   7 import com.google.common.collect.Lists;
   8 import com.google.datastore.v1beta3.EntityResult;
   9 import com.google.datastore.v1beta3.QueryResultBatch;
  10 import com.google.datastore.v1beta3.QueryResultBatch.MoreResultsType;
  11
  12 import java.util.Collection;
  13 import java.util.List;
  14
  15 /**
  16  * An implementation of {@link WrappedQueryResult} in terms of Cloud Datastore v1.
  17  */
  18 class WrappedQueryResultCloudDatastoreV1 implements WrappedQueryResult {
  19   private final QueryResultBatch batch;
  20
  21   WrappedQueryResultCloudDatastoreV1(QueryResultBatch batch) {
  22     this.batch = batch;
  23   }
  24
  25   @Override
  26   public Cursor getEndCursor() {
  27     checkState(!batch.getEndCursor().isEmpty(), "Batch contained no end cursor.");
  28     return new Cursor(batch.getEndCursor());
  29   }
  30
  31   @Override
  32   public List<Entity> getEntities(Collection<Projection> projections) {
  33     List<Entity> entityList = Lists.newArrayListWithCapacity(batch.getEntityResultsCount());
  34     if (projections.isEmpty()) {
  35       for (EntityResult entityResult : batch.getEntityResultsList()) {
  36         entityList.add(DataTypeTranslator.toEntity(entityResult.getEntity()));
  37       }
  38     } else {
  39       for (EntityResult entityResult : batch.getEntityResultsList()) {
  40         entityList.add(DataTypeTranslator.toEntity(entityResult.getEntity(), projections));
  41       }
  42     }
  43     return entityList;
  44   }
  45
  46   @Override
  47   public List<Cursor> getResultCursors() {
  48     List<Cursor> cursors = Lists.newArrayListWithCapacity(batch.getEntityResultsCount());
  49     for (EntityResult result : batch.getEntityResultsList()) {
  50       cursors.add(result.getCursor().isEmpty() ? null : new Cursor(result.getCursor()));
  51     }
  52     return cursors;
  53   }
  54
  55   @Override
  56   public Cursor getSkippedResultsCursor() {
  57     return batch.getSkippedCursor().isEmpty() ? null : new Cursor(batch.getSkippedCursor());
  58   }
  59
  60   @Override
  61   public boolean hasMoreResults() {
  62     return batch.getMoreResults() == MoreResultsType.NOT_FINISHED;
  63   }
  64
  65   @Override
  66   public int numSkippedResults() {
  67     return batch.getSkippedResults();
  68   }
  69
  70   @Override
  71   public List<Index> getIndexInfo(Collection<Index> monitoredIndexBuffer) {
  72     return ImmutableList.of();
  73   }
  74
  75   @Override
  76   public boolean madeProgress(WrappedQueryResult previousResult) {
  77     if (!hasMoreResults()) {
  78       return true;
  79     }
  80     return !getEndCursor().equals(previousResult.getEndCursor());
  81   }
  82
  83   QueryResultBatch getBatch() {
  84     return batch;
  85   }
  86 }