plugins/git4idea/src/git4idea/commands/GitHandler.java

/*
 * Copyright 2000-2013 JetBrains s.r.o.
 *
 * Licensed 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 git4idea.commands;

import com.intellij.execution.ExecutionException;
import com.intellij.execution.configurations.GeneralCommandLine;
import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.application.ModalityState;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.util.SystemInfo;
import com.intellij.openapi.vcs.FilePath;
import com.intellij.openapi.vcs.ProcessEventListener;
import com.intellij.openapi.vcs.VcsException;
import com.intellij.openapi.vfs.LocalFileSystem;
import com.intellij.openapi.vfs.VfsUtil;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.util.EventDispatcher;
import com.intellij.util.Processor;
import com.intellij.vcsUtil.VcsFileUtil;
import git4idea.GitVcs;
import git4idea.config.GitVcsApplicationSettings;
import git4idea.config.GitVcsSettings;
import git4idea.config.GitVersionSpecialty;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.git4idea.ssh.GitSSHHandler;
import org.jetbrains.git4idea.ssh.GitSSHService;

import java.io.File;
import java.io.OutputStream;
import java.nio.charset.Charset;
import java.util.*;
import java.util.concurrent.LinkedBlockingQueue;

/**
 * A handler for git commands
 */
public abstract class GitHandler {
  protected final Project myProject;
  protected final GitCommand myCommand;

  private final HashSet<Integer> myIgnoredErrorCodes = new HashSet<Integer>(); // Error codes that are ignored for the handler
  private final List<VcsException> myErrors = Collections.synchronizedList(new ArrayList<VcsException>());
  private final List<String> myLastOutput = Collections.synchronizedList(new ArrayList<String>());
  private final int LAST_OUTPUT_SIZE = 5;
  protected static final Logger LOG = Logger.getInstance(GitHandler.class.getName());
  final GeneralCommandLine myCommandLine;
  @SuppressWarnings({"FieldAccessedSynchronizedAndUnsynchronized"})
  Process myProcess;

  private boolean myStdoutSuppressed; // If true, the standard output is not copied to version control console
  private boolean myStderrSuppressed; // If true, the standard error is not copied to version control console
  private final File myWorkingDirectory;

  private boolean myEnvironmentCleanedUp = true; // the flag indicating that environment has been cleaned up, by default is true because there is nothing to clean
  private int myHandlerNo;
  private Processor<OutputStream> myInputProcessor; // The processor for stdin

  // if true process might be cancelled
  // note that access is safe because it accessed in unsynchronized block only after process is started, and it does not change after that
  @SuppressWarnings({"FieldAccessedSynchronizedAndUnsynchronized"})
  private boolean myIsCancellable = true;

  private Integer myExitCode; // exit code or null if exit code is not yet available

  @SuppressWarnings({"FieldAccessedSynchronizedAndUnsynchronized"})
  @NonNls
  private Charset myCharset = Charset.forName("UTF-8"); // Character set to use for IO

  @SuppressWarnings({"FieldAccessedSynchronizedAndUnsynchronized"})
  private boolean myNoSSHFlag = false;

  private final EventDispatcher<ProcessEventListener> myListeners = EventDispatcher.create(ProcessEventListener.class);
  @SuppressWarnings({"FieldAccessedSynchronizedAndUnsynchronized"})
  protected boolean mySilent; // if true, the command execution is not logged in version control view

  protected final GitVcs myVcs;
  private final Map<String, String> myEnv;
  private GitVcsApplicationSettings myAppSettings;
  private GitVcsSettings myProjectSettings;

  private Runnable mySuspendAction; // Suspend action used by {@link #suspendWriteLock()}
  private Runnable myResumeAction; // Resume action used by {@link #resumeWriteLock()}

  private long myStartTime; // git execution start timestamp
  private static final long LONG_TIME = 10 * 1000;
  @Nullable private ModalityState myState;


  /**
   * A constructor
   *
   * @param project   a project
   * @param directory a process directory
   * @param command   a command to execute (if empty string, the parameter is ignored)
   */
  protected GitHandler(@NotNull Project project, @NotNull File directory, @NotNull GitCommand command) {
    myProject = project;
    myCommand = command;
    myAppSettings = GitVcsApplicationSettings.getInstance();
    myProjectSettings = GitVcsSettings.getInstance(myProject);
    myEnv = new HashMap<String, String>(System.getenv());
    myVcs = GitVcs.getInstance(project);
    myWorkingDirectory = directory;
    myCommandLine = new GeneralCommandLine();
    if (myAppSettings != null) {
      myCommandLine.setExePath(myAppSettings.getPathToGit());
    }
    myCommandLine.setWorkDirectory(myWorkingDirectory);
    if (command.name().length() > 0) {
      myCommandLine.addParameter(command.name());
    }
  }

  /**
   * A constructor
   *
   * @param project a project
   * @param vcsRoot a process directory
   * @param command a command to execute
   */
  protected GitHandler(final Project project, final VirtualFile vcsRoot, final GitCommand command) {
    this(project, VfsUtil.virtualToIoFile(vcsRoot), command);
  }

  /**
   * @return multicaster for listeners
   */
  protected ProcessEventListener listeners() {
    return myListeners.getMulticaster();
  }

  /**
   * Add error code to ignored list
   *
   * @param code the code to ignore
   */
  public void ignoreErrorCode(int code) {
    myIgnoredErrorCodes.add(code);
  }

  /**
   * Check if error code should be ignored
   *
   * @param code a code to check
   * @return true if error code is ignorable
   */
  public boolean isIgnoredErrorCode(int code) {
    return myIgnoredErrorCodes.contains(code);
  }


  /**
   * add error to the error list
   *
   * @param ex an error to add to the list
   */
  public void addError(VcsException ex) {
    myErrors.add(ex);
  }

  public void addLastOutput(String line) {
    if (myLastOutput.size() < LAST_OUTPUT_SIZE) {
      myLastOutput.add(line);
    } else {
      myLastOutput.add(0, line);
      Collections.rotate(myLastOutput, -1);
    }
  }

  public List<String> getLastOutput() {
    return myLastOutput;
  }

  /**
   * @return unmodifiable list of errors.
   */
  public List<VcsException> errors() {
    return Collections.unmodifiableList(myErrors);
  }

  /**
   * @return a context project
   */
  public Project project() {
    return myProject;
  }

  /**
   * @return the current working directory
   */
  public File workingDirectory() {
    return myWorkingDirectory;
  }

  /**
   * @return the current working directory
   */
  public VirtualFile workingDirectoryFile() {
    final VirtualFile file = LocalFileSystem.getInstance().findFileByIoFile(workingDirectory());
    if (file == null) {
      throw new IllegalStateException("The working directly should be available: " + workingDirectory());
    }
    return file;
  }

  /**
   * Set SSH flag. This flag should be set to true for commands that never interact with remote repositories.
   *
   * @param value if value is true, the custom ssh is not used for the command.
   */
  @SuppressWarnings({"WeakerAccess", "SameParameterValue"})
  public void setNoSSH(boolean value) {
    checkNotStarted();
    myNoSSHFlag = value;
  }

  /**
   * @return true if SSH is not invoked by this command.
   */
  @SuppressWarnings({"WeakerAccess"})
  public boolean isNoSSH() {
    return myNoSSHFlag;
  }

  /**
   * Add listener to handler
   *
   * @param listener a listener
   */
  protected void addListener(ProcessEventListener listener) {
    myListeners.addListener(listener);
  }

  /**
   * End option parameters and start file paths. The method adds {@code "--"} parameter.
   */
  public void endOptions() {
    myCommandLine.addParameter("--");
  }

  /**
   * Add string parameters
   *
   * @param parameters a parameters to add
   */
  @SuppressWarnings({"WeakerAccess"})
  public void addParameters(@NonNls @NotNull String... parameters) {
    addParameters(Arrays.asList(parameters));
  }

  /**
   * Add parameters from the list
   *
   * @param parameters the parameters to add
   */
  public void addParameters(List<String> parameters) {
    checkNotStarted();
    for (String parameter : parameters) {
      myCommandLine.addParameter(escapeParameterIfNeeded(parameter));
    }
  }

  @NotNull
  private String escapeParameterIfNeeded(@NotNull String parameter) {
    if (escapeNeeded(parameter)) {
      return parameter.replaceAll("\\^", "^^^^");
    }
    return parameter;
  }

  private boolean escapeNeeded(@NotNull String parameter) {
    return SystemInfo.isWindows && isCmd() && parameter.contains("^");
  }

  private boolean isCmd() {
    return myAppSettings.getPathToGit().toLowerCase().endsWith("cmd");
  }

  @NotNull
  private String unescapeCommandLine(@NotNull String commandLine) {
    if (escapeNeeded(commandLine)) {
      return commandLine.replaceAll("\\^\\^\\^\\^", "^");
    }
    return commandLine;
  }

  /**
   * Add file path parameters. The parameters are made relative to the working directory
   *
   * @param parameters a parameters to add
   * @throws IllegalArgumentException if some path is not under root.
   */
  public void addRelativePaths(@NotNull FilePath... parameters) {
    addRelativePaths(Arrays.asList(parameters));
  }

  /**
   * Add file path parameters. The parameters are made relative to the working directory
   *
   * @param filePaths a parameters to add
   * @throws IllegalArgumentException if some path is not under root.
   */
  @SuppressWarnings({"WeakerAccess"})
  public void addRelativePaths(@NotNull final Collection<FilePath> filePaths) {
    checkNotStarted();
    for (FilePath path : filePaths) {
      myCommandLine.addParameter(VcsFileUtil.relativePath(myWorkingDirectory, path));
    }
  }

  /**
   * Add file path parameters. The parameters are made relative to the working directory
   *
   * @param files a parameters to add
   * @throws IllegalArgumentException if some path is not under root.
   */
  public void addRelativePathsForFiles(@NotNull final Collection<File> files) {
    checkNotStarted();
    for (File file : files) {
      myCommandLine.addParameter(VcsFileUtil.relativePath(myWorkingDirectory, file));
    }
  }

  /**
   * Add virtual file parameters. The parameters are made relative to the working directory
   *
   * @param files a parameters to add
   * @throws IllegalArgumentException if some path is not under root.
   */
  @SuppressWarnings({"WeakerAccess"})
  public void addRelativeFiles(@NotNull final Collection<VirtualFile> files) {
    checkNotStarted();
    for (VirtualFile file : files) {
      myCommandLine.addParameter(VcsFileUtil.relativePath(myWorkingDirectory, file));
    }
  }

  /**
   * Adds "--progress" parameter. Usable for long operations, such as clone or fetch.
   * @return is "--progress" parameter supported by this version of Git.
   */
  public boolean addProgressParameter() {
    if (GitVersionSpecialty.ABLE_TO_USE_PROGRESS_IN_REMOTE_COMMANDS.existsIn(myVcs.getVersion())) {
      addParameters("--progress");
      return true;
    }
    return false;
  }

  /**
   * check that process is not started yet
   *
   * @throws IllegalStateException if process has been already started
   */
  private void checkNotStarted() {
    if (isStarted()) {
      throw new IllegalStateException("The process has been already started");
    }
  }

  /**
   * check that process is started
   *
   * @throws IllegalStateException if process has not been started
   */
  protected final void checkStarted() {
    if (!isStarted()) {
      throw new IllegalStateException("The process is not started yet");
    }
  }

  /**
   * @return true if process is started
   */
  public final synchronized boolean isStarted() {
    return myProcess != null;
  }


  /**
   * Set new value of cancellable flag (by default true)
   *
   * @param value a new value of the flag
   */
  public void setCancellable(boolean value) {
    checkNotStarted();
    myIsCancellable = value;
  }

  /**
   * @return cancellable state
   */
  public boolean isCancellable() {
    return myIsCancellable;
  }

  /**
   * Start process
   */
  public synchronized void start() {
    checkNotStarted();

    try {
      myStartTime = System.currentTimeMillis();
      if (!myProject.isDefault() && !mySilent && (myVcs != null)) {
        myVcs.showCommandLine("cd " + myWorkingDirectory);
        myVcs.showCommandLine(printableCommandLine());
        LOG.info("cd " + myWorkingDirectory);
        LOG.info(printableCommandLine());
      }
      else {
        LOG.debug("cd " + myWorkingDirectory);
        LOG.debug(printableCommandLine());
      }

      // setup environment
      if (!myNoSSHFlag && myProjectSettings.isIdeaSsh()) {
        GitSSHService ssh = GitSSHIdeaService.getInstance();
        myEnv.put(GitSSHHandler.GIT_SSH_ENV, ssh.getScriptPath().getPath());
        myHandlerNo = ssh.registerHandler(new GitSSHGUIHandler(myProject, myState));
        myEnvironmentCleanedUp = false;
        myEnv.put(GitSSHHandler.SSH_HANDLER_ENV, Integer.toString(myHandlerNo));
        int port = ssh.getXmlRcpPort();
        myEnv.put(GitSSHHandler.SSH_PORT_ENV, Integer.toString(port));
        LOG.debug(String.format("handler=%s, port=%s", myHandlerNo, port));
      }
      myCommandLine.setEnvParams(myEnv);
      // start process
      myProcess = startProcess();
      startHandlingStreams();
    }
    catch (Throwable t) {
      cleanupEnv();
      myListeners.getMulticaster().startFailed(t);
    }
  }

  protected abstract Process startProcess() throws ExecutionException;

  /**
   * Start handling process output streams for the handler.
   */
  protected abstract void startHandlingStreams();

  /**
   * @return a command line with full path to executable replace to "git"
   */
  public String printableCommandLine() {
    return unescapeCommandLine(myCommandLine.getCommandLineString("git"));
  }

  /**
   * Cancel activity
   */
  public synchronized void cancel() {
    checkStarted();
    if (!myIsCancellable) {
      throw new IllegalStateException("The process is not cancellable.");
    }
    destroyProcess();
  }

  /**
   * Destroy process
   */
  public abstract void destroyProcess();

  /**
   * @return exit code for process if it is available
   */
  public synchronized int getExitCode() {
    if (myExitCode == null) {
      throw new IllegalStateException("Exit code is not yet available");
    }
    return myExitCode.intValue();
  }

  /**
   * @param exitCode a exit code for process
   */
  protected synchronized void setExitCode(int exitCode) {
    myExitCode = exitCode;
  }

  /**
   * Cleanup environment
   */
  protected synchronized void cleanupEnv() {
    if (!myNoSSHFlag && !myEnvironmentCleanedUp) {
      GitSSHService ssh = GitSSHIdeaService.getInstance();
      myEnvironmentCleanedUp = true;
      ssh.unregisterHandler(myHandlerNo);
    }
  }

  /**
   * Wait for process termination
   */
  public void waitFor() {
    checkStarted();
    try {
      if (myInputProcessor != null && myProcess != null) {
        myInputProcessor.process(myProcess.getOutputStream());
      }
    }
    finally {
      waitForProcess();
    }
  }

  /**
   * Wait for process
   */
  protected abstract void waitForProcess();

  /**
   * Set silent mode. When handler is silent, it does not logs command in version control console.
   * Note that this option also suppresses stderr and stdout copying.
   *
   * @param silent a new value of the flag
   * @see #setStderrSuppressed(boolean)
   * @see #setStdoutSuppressed(boolean)
   */
  @SuppressWarnings({"SameParameterValue"})
  public void setSilent(final boolean silent) {
    checkNotStarted();
    mySilent = silent;
    setStderrSuppressed(silent);
    setStdoutSuppressed(silent);
  }

  /**
   * @return a character set to use for IO
   */
  public Charset getCharset() {
    return myCharset;
  }

  /**
   * Set character set for IO
   *
   * @param charset a character set
   */
  @SuppressWarnings({"SameParameterValue"})
  public void setCharset(final Charset charset) {
    myCharset = charset;
  }

  /**
   * @return true if standard output is not copied to the console
   */
  public boolean isStdoutSuppressed() {
    return myStdoutSuppressed;
  }

  /**
   * Set flag specifying if stdout should be copied to the console
   *
   * @param stdoutSuppressed true if output is not copied to the console
   */
  public void setStdoutSuppressed(final boolean stdoutSuppressed) {
    checkNotStarted();
    myStdoutSuppressed = stdoutSuppressed;
  }

  /**
   * @return true if standard output is not copied to the console
   */
  public boolean isStderrSuppressed() {
    return myStderrSuppressed;
  }

  /**
   * Set flag specifying if stderr should be copied to the console
   *
   * @param stderrSuppressed true if error output is not copied to the console
   */
  public void setStderrSuppressed(final boolean stderrSuppressed) {
    checkNotStarted();
    myStderrSuppressed = stderrSuppressed;
  }

  /**
   * Set environment variable
   *
   * @param name  the variable name
   * @param value the variable value
   */
  public void setEnvironment(String name, String value) {
    myEnv.put(name, value);
  }

  /**
   * Set processor for standard input. This is a place where input to the git application could be generated.
   *
   * @param inputProcessor the processor
   */
  public void setInputProcessor(Processor<OutputStream> inputProcessor) {
    myInputProcessor = inputProcessor;
  }

  /**
   * Set suspend/resume actions
   *
   * @param suspend the suspend action
   * @param resume  the resume action
   */
  synchronized void setSuspendResume(Runnable suspend, Runnable resume) {
    mySuspendAction = suspend;
    myResumeAction = resume;
  }

  /**
   * Suspend write lock held by the handler
   */
  public synchronized void suspendWriteLock() {
    assert mySuspendAction != null;
    mySuspendAction.run();
  }

  /**
   * Resume write lock held by the handler
   */
  public synchronized void resumeWriteLock() {
    assert mySuspendAction != null;
    myResumeAction.run();
  }

  public void setModalityState(@Nullable ModalityState state) {
    myState = state;
  }

  /**
   * @return true if the command line is too big
   */
  public boolean isLargeCommandLine() {
    return myCommandLine.getCommandLineString().length() > VcsFileUtil.FILE_PATH_LIMIT;
  }

  public void runInCurrentThread(@Nullable Runnable postStartAction) {
    //LOG.assertTrue(!ApplicationManager.getApplication().isDispatchThread(), "Git process should never start in the dispatch thread.");

        final GitVcs vcs = GitVcs.getInstance(myProject);
    if (vcs == null) { return; }

    boolean suspendable = false;
    switch (myCommand.lockingPolicy()) {
      case READ:
        // need to lock only write operations: reads can be performed even when a write operation is going on
        break;
      case WRITE_SUSPENDABLE:
        suspendable = true;
        //noinspection fallthrough
      case WRITE:
        vcs.getCommandLock().writeLock().lock();
        break;
    }
    try {
      if (suspendable) {
        final Object EXIT = new Object();
        final Object SUSPEND = new Object();
        final Object RESUME = new Object();
        final LinkedBlockingQueue<Object> queue = new LinkedBlockingQueue<Object>();
        Runnable suspend = new Runnable() {
          public void run() {
            queue.add(SUSPEND);
          }
        };
        Runnable resume = new Runnable() {
          public void run() {
            queue.add(RESUME);
          }
        };
        setSuspendResume(suspend, resume);
        start();
        if (isStarted()) {
          if (postStartAction != null) {
            postStartAction.run();
          }
          ApplicationManager.getApplication().executeOnPooledThread(new Runnable() {
            public void run() {
              waitFor();
              queue.add(EXIT);
            }
          });
          boolean suspended = false;
          while (true) {
            Object action;
            while (true) {
              try {
                action = queue.take();
                break;
              }
              catch (InterruptedException e) {
                if (LOG.isDebugEnabled()) {
                  LOG.debug("queue.take() is interrupted", e);
                }
              }
            }
            if (action == EXIT) {
              if (suspended) {
                LOG.error("Exiting while RW lock is suspended (reacquiring W-lock command)");
                vcs.getCommandLock().writeLock().lock();
              }
              break;
            }
            else if (action == SUSPEND) {
              if (suspended) {
                LOG.error("Suspending suspended W-lock (ignoring command)");
              }
              else {
                vcs.getCommandLock().writeLock().unlock();
                suspended = true;
              }
            }
            else if (action == RESUME) {
              if (!suspended) {
                LOG.error("Resuming not suspended W-lock (ignoring command)");
              }
              else {
                vcs.getCommandLock().writeLock().lock();
                suspended = false;
              }
            }
          }
        }
      }
      else {
        start();
        if (isStarted()) {
          if (postStartAction != null) {
            postStartAction.run();
          }
          waitFor();
        }
      }
    }
    finally {
      switch (myCommand.lockingPolicy()) {
        case READ:
          break;
        case WRITE_SUSPENDABLE:
        case WRITE:
          vcs.getCommandLock().writeLock().unlock();
          break;
      }

      logTime();
    }
  }

  private void logTime() {
    if (myStartTime > 0) {
      long time = System.currentTimeMillis() - myStartTime;
      if (!LOG.isDebugEnabled() && time > LONG_TIME) {
        LOG.info(String.format("git %s took %s ms. Command parameters: %n%s", myCommand, time, myCommandLine.getCommandLineString()));
      }
      else {
        LOG.debug(String.format("git %s took %s ms", myCommand, time));
      }
    }
    else {
      LOG.debug(String.format("git %s finished.", myCommand));
    }
  }

  @Override
  public String toString() {
    return myCommandLine.toString();
  }
}