/*
    * ====================================================================
    * 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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  package org.apache.http.impl.client.cache;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  
  import org.apache.http.annotation.Contract;
  import org.apache.http.annotation.ThreadingBehavior;
  import org.apache.http.client.cache.InputLimit;
  import org.apache.http.client.cache.Resource;
  import org.apache.http.client.cache.ResourceFactory;
  
  /**
   * Generates {@link Resource} instances stored entirely in heap.
   *
   * @since 4.1
   */
  @Contract(threading = ThreadingBehavior.IMMUTABLE)
  public class HeapResourceFactory implements ResourceFactory {
  
      @Override
      public Resource generate(
              final String requestId,
              final InputStream inStream,
              final InputLimit limit) throws IOException {
          final ByteArrayOutputStream outStream = new ByteArrayOutputStream();
          final byte[] buf = new byte[2048];
          long total = 0;
          int l;
          while ((l = inStream.read(buf)) != -1) {
              outStream.write(buf, 0, l);
              total += l;
              if (limit != null && total > limit.getValue()) {
                  limit.reached();
                  break;
              }
          }
          return createResource(outStream.toByteArray());
      }
  
      @Override
      public Resource copy(
              final String requestId,
              final Resource resource) throws IOException {
          final byte[] body;
          if (resource instanceof HeapResource) {
              body = ((HeapResource) resource).getByteArray();
          } else {
              final ByteArrayOutputStream outStream = new ByteArrayOutputStream();
              IOUtils.copyAndClose(resource.getInputStream(), outStream);
              body = outStream.toByteArray();
          }
          return createResource(body);
      }
  
      Resource createResource(final byte[] buf) {
          return new HeapResource(buf);
      }
  
  }