RewriteRuleHandler.java

package com.splout.db.qnode.rest;

/*
 * #%L
 * Splout SQL Server
 * %%
 * Copyright (C) 2012 Datasalt Systems S.L.
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * #L%
 */

import org.mortbay.jetty.handler.HandlerWrapper;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.HashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * We don't use Jetty's rewrite handler because it has a bug which is not fixed until version 8.
 */
public class RewriteRuleHandler extends HandlerWrapper {

  Pattern tablespaceInfo = Pattern.compile("/api/tablespace/([^/]*)(/)?");
  Pattern tablespaceVersions = Pattern.compile("/api/tablespace/([^/]*)/versions(/)?");
  Pattern dnodeInfo = Pattern.compile("/api/dnode/([^/]*)(/|/status)?");
  Pattern query = Pattern.compile("/api/query/([^/]*)(/)?");

  /**
   * An implementation of HttpServletRequestWrapper which we can use to add more parameters if we want.
   */
  public static class MutableHttpRequest extends HttpServletRequestWrapper {

    private HashMap<String, String> params = new HashMap<String, String>();

    public MutableHttpRequest(HttpServletRequest request) {
      super(request);
    }

    public String getParameter(String name) {
      // if we added one, return that one
      if (params.get(name) != null) {
        return params.get(name);
      }
      // otherwise return what's in the original request
      HttpServletRequest req = (HttpServletRequest) super.getRequest();
      return req.getParameter(name);
    }

    public void addParameter(String name, String value) {
      params.put(name, value);
    }
  }

  @Override
  public void handle(String target, HttpServletRequest request, HttpServletResponse response,
                     int dispatch) throws IOException, ServletException {

    /**
     * {@link QueryServlet} rewrite rules
     */
    Matcher m = query.matcher(target);
    if (m.matches()) {
      String tablespace = m.group(1);
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("tablespace", tablespace);
      super.handle("/api/query", req, response, dispatch);
    }

    /**
     * {@link AdminServlet} rewrite rules
     */

    if (target.startsWith("/api/deployments")) {
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", AdminServlet.ACTION_DEPLOYMENTS_STATUS);
      super.handle("/api/admin", req, response, dispatch);
    }

    if (target.startsWith("/api/overview")) {
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", AdminServlet.ACTION_OVERVIEW);
      super.handle("/api/admin", req, response, dispatch);
    }

    if (target.startsWith("/api/dnodelist")) {
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", AdminServlet.ACTION_DNODE_LIST);
      super.handle("/api/admin", req, response, dispatch);
    }

    if (target.startsWith("/api/tablespaces")) {
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", AdminServlet.ACTION_TABLESPACES);
      super.handle("/api/admin", req, response, dispatch);
    }

    if (target.startsWith("/api/cleanoldversions")) {
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", AdminServlet.ACTION_CLEAN_OLD_VERSIONS);
      super.handle("/api/admin", req, response, dispatch);
    }

    m = tablespaceInfo.matcher(target);
    if (m.matches()) {
      String tablespace = m.group(1);
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", AdminServlet.ACTION_TABLESPACE_INFO);
      req.addParameter("tablespace", tablespace);
      super.handle("/api/admin", req, response, dispatch);
    }

    m = dnodeInfo.matcher(target);
    if (m.matches()) {
      String dnode = m.group(1);
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", AdminServlet.ACTION_DNODE_STATUS);
      req.addParameter("dnode", dnode);
      super.handle("/api/admin", req, response, dispatch);
    }

    m = tablespaceVersions.matcher(target);
    if (m.matches()) {
      String tablespace = m.group(1);
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", AdminServlet.ACTION_ALL_TABLESPACE_VERSIONS);
      req.addParameter("tablespace", tablespace);
      super.handle("/api/admin", req, response, dispatch);
    }

    /**
     * {@link DeployRollbackServlet} rewrite rules
     */
    if (target.startsWith("/api/deploy")) {
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", DeployRollbackServlet.ACTION_DEPLOY);
      super.handle("/api/deploy", req, response, dispatch);
    }

    if (target.startsWith("/api/rollback")) {
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", DeployRollbackServlet.ACTION_ROLLBACK);
      super.handle("/api/deploy", req, response, dispatch);
    }

    if (target.startsWith("/api/canceldeployment")) {
      MutableHttpRequest req = new MutableHttpRequest(request);
      req.addParameter("action", DeployRollbackServlet.ACTION_CANCEL_DEPLOYMENT);
      super.handle("/api/deploy", req, response, dispatch);
    }

    super.handle(target, request, response, dispatch);
  }
}