WebInterfaceMemoryServlet.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 tachyon.web;

import tachyon.master.MasterInfo;
import tachyon.thrift.ClientFileInfo;
import tachyon.thrift.FileDoesNotExistException;
import tachyon.thrift.InvalidPathException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Servlet that provides data for displaying which files are currently in memory.
 */
public class WebInterfaceMemoryServlet extends HttpServlet {
  private static final long serialVersionUID = 4293149962399443914L;
  private MasterInfo mMasterInfo;

  public WebInterfaceMemoryServlet(MasterInfo masterInfo) {
    mMasterInfo = masterInfo;
  }

  /**
   * Populates attributes before redirecting to a jsp.
   * 
   * @param request
   *          The HttpServletRequest object
   * @param response
   *          The HttpServletReponse object
   */
  @Override
  public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    request.setAttribute("masterNodeAddress", mMasterInfo.getMasterAddress().toString());

    List<String> inMemoryFiles = mMasterInfo.getInMemoryFiles();
    Collections.sort(inMemoryFiles);
    request.setAttribute("inMemoryFiles", inMemoryFiles);

    List<UiFileInfo> fileInfos = new ArrayList<UiFileInfo>(inMemoryFiles.size());
    for (String file : inMemoryFiles) {
      ClientFileInfo fileInfo = null;
      try {
        fileInfo = mMasterInfo.getClientFileInfo(file);
      } catch (InvalidPathException ipe) {
        request.setAttribute("invalidPathError",
            "Error: Invalid Path " + ipe.getLocalizedMessage());
        getServletContext().getRequestDispatcher("/memory.jsp").forward(request, response);
        return;
      } catch (FileDoesNotExistException fdne) {
        // ignore
      }
      if (fileInfo.getInMemoryPercentage() == 100) {
        fileInfos.add(new UiFileInfo(fileInfo));
      }
    }
    request.setAttribute("fileInfos", fileInfos);

    getServletContext().getRequestDispatcher("/memory.jsp").forward(request, response);
  }
}