Java 类org.apache.hadoop.hdfs.server.namenode.GetImageServlet 实例源码

@Override
public void doGet(final HttpServletRequest request,
    final HttpServletResponse response) throws ServletException, IOException {
  try {
    final GetImageParams parsedParams = new GetImageParams(request, response);

    // here we only support getImage
    if (!parsedParams.isGetImage()) {
      throw new IOException("Only getImage requests are supported");
    }

    // get access to journal node storage
    final ServletContext context = getServletContext();
    final Configuration conf = (Configuration) getServletContext()
        .getAttribute(JspHelper.CURRENT_CONF);
    final String journalId = request.getParameter(JOURNAL_ID_PARAM);
    QuorumJournalManager.checkJournalId(journalId);

    final Journal journal = JournalNodeHttpServer.getJournalFromContext(
        context, journalId);
    final JNStorage imageStorage = journal.getImageStorage();

    final JournalMetrics metrics = journal.getMetrics();
    if (metrics != null) {
      metrics.numGetImageDoGet.inc();
    }

    // Check that the namespace info is correct
    if (!GetJournalEditServlet.checkStorageInfoOrSendError(imageStorage,
        request, response)) {
      return;
    }

    // we will serve image at txid
    long txid = parsedParams.getTxId();
    File imageFile = imageStorage.getImageFile(txid);

    // no such image in the storage
    if (imageFile == null) {
      throw new IOException("Could not find image with txid " + txid);
    }

    // set verification headers 
    setVerificationHeaders(response, imageFile);

    // send fsImage
    TransferFsImage.getFileServer(response.getOutputStream(), imageFile,
        GetImageServlet.getThrottler(conf, parsedParams.isThrottlerDisabled()));

  } catch (Throwable t) {
    GetJournalEditServlet.handleFailure(t, response, "getImage");
  } 
}

@Override
public void doGet(final HttpServletRequest request,
    final HttpServletResponse response) throws ServletException, IOException {
  FileInputStream editFileIn = null;
  try {
    final ServletContext context = getServletContext();
    final Configuration conf = (Configuration) getServletContext()
        .getAttribute(JspHelper.CURRENT_CONF);
    final String journalId = request.getParameter(JOURNAL_ID_PARAM);
    QuorumJournalManager.checkJournalId(journalId);
    final JNStorage storage = JournalNodeHttpServer
        .getJournalFromContext(context, journalId).getStorage();

    // Check security
    if (!checkRequestorOrSendError(conf, request, response)) {
      return;
    }

    // Check that the namespace info is correct
    if (!checkStorageInfoOrSendError(storage, request, response)) {
      return;
    }

    long segmentTxId = ServletUtil.parseLongParam(request,
        SEGMENT_TXID_PARAM);

    FileJournalManager fjm = storage.getJournalManager();
    File editFile;

    synchronized (fjm) {
      // Synchronize on the FJM so that the file doesn't get finalized
      // out from underneath us while we're in the process of opening
      // it up.
      EditLogFile elf = fjm.getLogFile(
          segmentTxId);
      if (elf == null) {
        response.sendError(HttpServletResponse.SC_NOT_FOUND,
            "No edit log found starting at txid " + segmentTxId);
        return;
      }
      editFile = elf.getFile();
      GetImageServlet.setVerificationHeaders(response, editFile);
      GetImageServlet.setFileNameHeaders(response, editFile);
      editFileIn = new FileInputStream(editFile);
    }

    DataTransferThrottler throttler = GetImageServlet.getThrottler(conf);

    // send edits
    TransferFsImage.getFileServer(response, editFile, editFileIn, throttler);

  } catch (Throwable t) {
    String errMsg = "getedit failed. " + StringUtils.stringifyException(t);
    response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, errMsg);
    throw new IOException(errMsg);
  } finally {
    IOUtils.closeStream(editFileIn);
  }
}

@Override
public void doGet(final HttpServletRequest request,
    final HttpServletResponse response) throws ServletException, IOException {
  FileInputStream editFileIn = null;
  try {
    final ServletContext context = getServletContext();
    final Configuration conf = (Configuration) getServletContext()
        .getAttribute(JspHelper.CURRENT_CONF);
    final String journalId = request.getParameter(JOURNAL_ID_PARAM);
    QuorumJournalManager.checkJournalId(journalId);
    final JNStorage storage = JournalNodeHttpServer
        .getJournalFromContext(context, journalId).getStorage();

    // Check security
    if (!checkRequestorOrSendError(conf, request, response)) {
      return;
    }

    // Check that the namespace info is correct
    if (!checkStorageInfoOrSendError(storage, request, response)) {
      return;
    }

    long segmentTxId = ServletUtil.parseLongParam(request,
        SEGMENT_TXID_PARAM);

    FileJournalManager fjm = storage.getJournalManager();
    File editFile;

    synchronized (fjm) {
      // Synchronize on the FJM so that the file doesn't get finalized
      // out from underneath us while we're in the process of opening
      // it up.
      EditLogFile elf = fjm.getLogFile(
          segmentTxId);
      if (elf == null) {
        response.sendError(HttpServletResponse.SC_NOT_FOUND,
            "No edit log found starting at txid " + segmentTxId);
        return;
      }
      editFile = elf.getFile();
      GetImageServlet.setVerificationHeaders(response, editFile);
      GetImageServlet.setFileNameHeaders(response, editFile);
      editFileIn = new FileInputStream(editFile);
    }

    DataTransferThrottler throttler = GetImageServlet.getThrottler(conf);

    // send edits
    TransferFsImage.getFileServer(response, editFile, editFileIn, throttler);

  } catch (Throwable t) {
    String errMsg = "getedit failed. " + StringUtils.stringifyException(t);
    response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, errMsg);
    throw new IOException(errMsg);
  } finally {
    IOUtils.closeStream(editFileIn);
  }
}

@Override
public void doGet(final HttpServletRequest request,
    final HttpServletResponse response) throws ServletException, IOException {
  FileInputStream editFileIn = null;
  try {
    final ServletContext context = getServletContext();
    final Configuration conf = (Configuration) getServletContext()
        .getAttribute(JspHelper.CURRENT_CONF);
    final String journalId = request.getParameter(JOURNAL_ID_PARAM);
    QuorumJournalManager.checkJournalId(journalId);
    final JNStorage storage = JournalNodeHttpServer
        .getJournalFromContext(context, journalId).getStorage();

    // Check security
    if (!checkRequestorOrSendError(conf, request, response)) {
      return;
    }

    // Check that the namespace info is correct
    if (!checkStorageInfoOrSendError(storage, request, response)) {
      return;
    }

    long segmentTxId = ServletUtil.parseLongParam(request,
        SEGMENT_TXID_PARAM);

    FileJournalManager fjm = storage.getJournalManager();
    File editFile;

    synchronized (fjm) {
      // Synchronize on the FJM so that the file doesn't get finalized
      // out from underneath us while we're in the process of opening
      // it up.
      EditLogFile elf = fjm.getLogFile(
          segmentTxId);
      if (elf == null) {
        response.sendError(HttpServletResponse.SC_NOT_FOUND,
            "No edit log found starting at txid " + segmentTxId);
        return;
      }
      editFile = elf.getFile();
      GetImageServlet.setVerificationHeaders(response, editFile);
      GetImageServlet.setFileNameHeaders(response, editFile);
      editFileIn = new FileInputStream(editFile);
    }

    DataTransferThrottler throttler = GetImageServlet.getThrottler(conf);

    // send edits
    TransferFsImage.getFileServer(response, editFile, editFileIn, throttler);

  } catch (Throwable t) {
    String errMsg = "getedit failed. " + StringUtils.stringifyException(t);
    response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, errMsg);
    throw new IOException(errMsg);
  } finally {
    IOUtils.closeStream(editFileIn);
  }
}