blobstore/src/main/java/org/jclouds/blobstore/options/ListOptions.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jclouds.blobstore.options;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;

/**
 * Contains options supported in the list container operation. <h2>
 * Usage</h2> The recommended way to instantiate a ListOptions object is to statically import
 * ListOptions.* and invoke a static creation method followed by an instance mutator (if needed):
 * <p/>
 * <code>
 * import static org.jclouds.blobstore.options.ListOptions.Builder.*
 * <p/>
 * BlobStore connection = // get connection
 * Future<BoundedSortedSet<ResourceMetadata>> list = connection.list(maxResults(1000));
 * <code>
 */
public class ListOptions implements Cloneable {

   public static class ImmutableListOptions extends ListOptions {
      private final ListOptions delegate;

      @Override
      public ListContainerOptions afterMarker(String marker) {
         throw new UnsupportedOperationException();
      }

      public ImmutableListOptions(ListOptions delegate) {
         this.delegate = delegate;
      }

      @Override
      public ListContainerOptions maxResults(int maxKeys) {
         throw new UnsupportedOperationException();
      }

      @Override
      public String getMarker() {
         return delegate.getMarker();
      }

      @Override
      public Integer getMaxResults() {
         return delegate.getMaxResults();
      }

      @Override
      public ListOptions clone() {
         return delegate.clone();
      }

      @Override
      public String toString() {
         return delegate.toString();
      }
   }

   public static final ImmutableListOptions NONE = new ImmutableListOptions(new ListOptions());

   ListOptions(Integer maxKeys, String marker) {
      this.maxKeys = maxKeys;
      this.marker = marker;
   }

   public ListOptions() {
   }

   private Integer maxKeys;
   private String marker;

   public Integer getMaxResults() {
      return maxKeys;
   }

   public String getMarker() {
      return marker;
   }

   /**
    * Place to continue a listing at. This must be the value returned from the last list object, as
    * not all blobstores use lexicographic lists.
    */
   public ListOptions afterMarker(String marker) {
      this.marker = checkNotNull(marker, "marker");
      return this;
   }

   /**
    * The maximum number of values you'd like to see in the response body. The server might return
    * fewer than this many values, but will not return more.
    */
   public ListOptions maxResults(int maxKeys) {
      checkArgument(maxKeys >= 0, "maxKeys must be >= 0");
      this.maxKeys = maxKeys;
      return this;
   }

   public static class Builder {

      /**
       * @see ListOptions#afterMarker(String)
       */
      public static ListOptions afterMarker(String marker) {
         ListOptions options = new ListOptions();
         return options.afterMarker(marker);
      }

      /**
       * @see ListOptions#maxResults(int)
       */
      public static ListOptions maxResults(int maxKeys) {
         ListOptions options = new ListOptions();
         return options.maxResults(maxKeys);
      }

   }

   @Override
   protected ListOptions clone() {
      return new ListOptions(maxKeys, marker);
   }
}