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.alibaba.jstorm.container.cgroup.core;
  
  import java.io.IOException;
  
  import com.alibaba.jstorm.container.CgroupUtils;
  import com.alibaba.jstorm.container.Constants;
  import com.alibaba.jstorm.container.SubSystemType;
  import com.alibaba.jstorm.container.cgroup.Device;
  
  public class NetClsCore implements CgroupCore {
  
      public static final String NET_CLS_CLASSID = "/net_cls.classid";
  
      private final String dir;
  
      public NetClsCore(String dir) {
          this.dir = dir;
      }
  
      @Override
      public SubSystemType getType() {
          return SubSystemType.net_cls;
      }
  
      private StringBuilder toHex(int num) {
          String hex = num + "";
          StringBuilder sb = new StringBuilder();
          int l = hex.length();
          if (l > 4) {
              hex = hex.substring(l - 4 - 1, l);
          }
          for (; l < 4; l++) {
              sb.append('0');
          }
          sb.append(hex);
          return sb;
      }
  
      public void setClassId(int major, int minor) throws IOException {
          StringBuilder sb = new StringBuilder("0x");
          sb.append(toHex(major));
          sb.append(toHex(minor));
          CgroupUtils.writeFileByLine(Constants.getDir(this.dir, NET_CLS_CLASSID), sb.toString());
      }
  
      public Device getClassId() throws IOException {
          String output = CgroupUtils.readFileByLine(Constants.getDir(this.dir, NET_CLS_CLASSID)).get(0);
          output = Integer.toHexString(Integer.parseInt(output));
          int major = Integer.parseInt(output.substring(0, output.length() - 4));
          int minor = Integer.parseInt(output.substring(output.length() - 4));
          return new Device(major, minor);
      }
  
  }
  