content: /*
   * Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package openjdk.tools.sjavac.server;
  
  import openjdk.tools.javac.main.Main;
  import openjdk.tools.sjavac.Log;
  import openjdk.tools.sjavac.Util;
  
  import java.io.BufferedReader;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.net.Socket;
  import java.nio.file.Path;
  
  import static openjdk.tools.sjavac.server.SjavacServer.LINE_TYPE_RC;
  
  
  /**
   * A RequestHandler handles requests performed over a socket. Specifically it
   *  - Reads the command string specifying which method is to be invoked
   *  - Reads the appropriate arguments
   *  - Delegates the actual invocation to the given sjavac implementation
   *  - Writes the result back to the socket output stream
   *
   * None of the work performed by this class is really bound by the CPU. It
   * should be completely fine to have a large number of RequestHandlers active.
   * To limit the number of concurrent compilations, use PooledSjavac.
   *
   *  <p><b>This is NOT part of any supported API.
   *  If you write code that depends on this, you do so at your own risk.
   *  This code and its internal interfaces are subject to change or
   *  deletion without notice.</b>
   */
  public class RequestHandler extends Thread {
  
      private final Socket socket;
      private final Sjavac sjavac;
  
      public RequestHandler(Socket socket, Sjavac sjavac) {
          this.socket = socket;
          this.sjavac = sjavac;
      }
  
      @Override
      public void run() {
  
          try (BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
               PrintWriter out = new PrintWriter(socket.getOutputStream(), true)) {
  
              // Set up logging for this thread. Stream back logging messages to
              // client on the format format "level:msg".
              Log.setLogForCurrentThread(new Log(out, out) {
                  @Override
                  protected boolean isLevelLogged(Level l) {
                      // Make sure it is up to the client to decide whether or
                      // not this message should be displayed.
                      return true;
                  }
  
                  @Override
                  protected void printLogMsg(Level msgLevel, String msg) {
                      // Follow sjavac server/client protocol: Send one line
                      // at a time and prefix with message with "level:".
                      Util.getLines(msg)
                          .map(line -> msgLevel + ":" + line)
                          .forEach(line -> super.printLogMsg(msgLevel, line));
                  }
              });
  
              // Read argument array
              int n = Integer.parseInt(in.readLine());
              String[] args = new String[n];
              for (int i = 0; i < n; i++) {
                  args[i] = in.readLine();
              }
  
              // If there has been any internal errors, notify client
              checkInternalErrorLog();
  
              // Perform compilation
              Main.Result rc = sjavac.compile(args);
  
              // Send return code back to client
              out.println(LINE_TYPE_RC + ":" + rc.name());
  
              // Check for internal errors again.
              checkInternalErrorLog();
          } catch (Exception ex) {
              // Not much to be done at this point. The client side request
              // code will most likely throw an IOException and the
              // compilation will fail.
              Log.error(ex);
          } finally {
              Log.setLogForCurrentThread(null);
          }
      }
  
      private void checkInternalErrorLog() {
          Path errorLog = ServerMain.getErrorLog().getLogDestination();
          if (errorLog != null) {
              Log.error("Server has encountered an internal error. See " + errorLog.toAbsolutePath()
                      + " for details.");
          }
      }
  }
  