content: //
  // 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 com.cloud.storage.template;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.util.Map;
  
  import javax.naming.ConfigurationException;
  
  import com.cloud.exception.InternalErrorException;
  
  import com.cloud.storage.Storage.ImageFormat;
  import com.cloud.storage.StorageLayer;
  import com.cloud.utils.NumbersUtil;
  import com.cloud.utils.component.AdapterBase;
  
  public class QCOW2Processor extends AdapterBase implements Processor {
      private static final int VIRTUALSIZE_HEADER_LOCATION = 24;
  
      private StorageLayer _storage;
  
     @Override
     public FormatInfo process(String templatePath, ImageFormat format, String templateName) throws InternalErrorException  {
       return process(templatePath, format, templateName, 0);
     }
  
      @Override
      public FormatInfo process(String templatePath, ImageFormat format, String templateName, long processTimeout) throws InternalErrorException {
          if (format != null) {
              logger.debug("We currently don't handle conversion from " + format + " to QCOW2.");
              return null;
          }
  
          String qcow2Path = templatePath + File.separator + templateName + "." + ImageFormat.QCOW2.getFileExtension();
  
          if (!_storage.exists(qcow2Path)) {
              logger.debug("Unable to find the qcow2 file: " + qcow2Path);
              return null;
          }
  
          FormatInfo info = new FormatInfo();
          info.format = ImageFormat.QCOW2;
          info.filename = templateName + "." + ImageFormat.QCOW2.getFileExtension();
  
          File qcow2File = _storage.getFile(qcow2Path);
  
          info.size = _storage.getSize(qcow2Path);
  
          try {
              info.virtualSize = getTemplateVirtualSize(qcow2File);
          } catch (IOException e) {
              logger.error("Unable to get virtual size from " + qcow2File.getName());
              throw new InternalErrorException("unable to get virtual size from qcow2 file");
          }
  
          return info;
      }
  
      @Override
      public long getVirtualSize(File file) throws IOException {
          try {
              long size = getTemplateVirtualSize(file);
              return size;
          } catch (Exception e) {
              logger.info("[ignored]" + "failed to get template virtual size for QCOW2: " + e.getLocalizedMessage());
          }
          return file.length();
      }
  
      protected long getTemplateVirtualSize(File file) throws IOException {
          byte[] b = new byte[8];
          try (FileInputStream strm = new FileInputStream(file)) {
              if (strm.skip(VIRTUALSIZE_HEADER_LOCATION) != VIRTUALSIZE_HEADER_LOCATION) {
                  throw new IOException("Unable to skip to the virtual size header");
              }
              if (strm.read(b) != 8) {
                  throw new IOException("Unable to properly read the size");
              }
          }
  
          return NumbersUtil.bytesToLong(b);
      }
  
      @Override
      public boolean configure(String name, Map<String, Object> params) throws ConfigurationException {
          _storage = (StorageLayer)params.get(StorageLayer.InstanceConfigKey);
          if (_storage == null) {
              throw new ConfigurationException("Unable to get storage implementation");
          }
  
          return true;
      }
  }
  