chesshog-uci/src/main/java/org/hedgecode/chess/uci/ExternalEngineRunner.java

   1 /*
   2  * Copyright (c) 2018. Developed by Hedgecode.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *   http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package org.hedgecode.chess.uci;
  18
  19 import java.io.IOException;
  20 import java.util.List;
  21
  22 import org.hedgecode.chess.uci.annotation.CommandDirection;
  23 import org.hedgecode.chess.uci.command.CommandParams;
  24
  25 /**
  26  * External UCI Engine Runner.
  27  *
  28  * @author Dmitry Samoshin aka gotty
  29  */
  30 public final class ExternalEngineRunner implements EngineRunner {
  31
  32     private Process process;
  33     private ProcessBuilder processBuilder;
  34
  35     private ExternalEngine engine;
  36
  37     private boolean isInit = false;
  38
  39     ExternalEngineRunner(String extEngineCommand) {
  40         processBuilder = new ProcessBuilder(extEngineCommand);
  41     }
  42
  43     ExternalEngineRunner(List<String> extEngineCommands) {
  44         processBuilder = new ProcessBuilder(extEngineCommands);
  45     }
  46
  47     @Override
  48     public Engine init() throws EngineException {
  49         if (isInit)
  50             throw new EngineException("uci.engine.already.init");
  51
  52         try {
  53             process = processBuilder.start();
  54         } catch (IOException e) {
  55             throw new EngineException("uci.engine.external.start", e.getLocalizedMessage());
  56         }
  57
  58         engine = new ExternalEngine(
  59                 process.getInputStream(),
  60                 process.getOutputStream()
  61         );
  62         isInit = true;
  63
  64         return engine;
  65     }
  66
  67     @Override
  68     public void run(final CommandExecutor commandExecutor) throws EngineException {
  69         if (!isInit)
  70             throw new EngineException("uci.engine.not.init");
  71
  72         Thread engineThread = new Thread(
  73                 new Runnable() {
  74                     public void run() {
  75                         Transmitter<String> engineTransmitter = engine.transmitter();
  76                         try {
  77                             while (engineTransmitter.hasCommand()) {
  78                                 String command = engineTransmitter.transmitCommand();
  79                                 if (command.isEmpty()) continue;
  80                                 CommandParams commandParams = new CommandParams(command);
  81                                 commandExecutor.exec(
  82                                         commandParams.getName(),
  83                                         CommandDirection.FROM_ENGINE,
  84                                         commandParams.getParams()
  85                                 );
  86                             }
  87                         } finally {
  88                             commandExecutor.exec(
  89                                     UCIConstants.TERMINATE,
  90                                     CommandDirection.FROM_ENGINE,
  91                                     null
  92                             );
  93                             engineTransmitter.stop();
  94                             engineTransmitter.close();
  95                             if (process.isAlive()) process.destroy();
  96                             isInit = false;
  97                         }
  98                     }
  99                 }
 100         );
 101         engineThread.start();
 102     }
 103
 104 }