Class WebModules

basex-api/src/main/java/org/basex/http/web/WebModules.java:29–382

This class caches RESTXQ modules found in the HTTP root directory. @author BaseX Team, BSD License @author Christian Gruen

 * @author Christian Gruen
 */
public final class WebModules {
  /** Singleton instance. */
  private static volatile WebModules instance;

  /** RESTXQ path. */
  private final IOFile path;

  /** Module cache. */
  private HashMap<String, WebModule> modules = new HashMap<>();
  /** Indicates if modules have been cached. */
  private boolean parsed;
  /** Last access time. */
  private long access;

  /**
   * Private constructor.
   * @param ctx database context
   */
  private WebModules(final Context ctx) {
    final StaticOptions sopts = ctx.soptions;
    final String webpath = sopts.get(StaticOptions.WEBPATH);
    final String rxqpath = sopts.get(StaticOptions.RESTXQPATH);
    path = new IOFile(webpath).resolve(rxqpath);

    // RESTXQ parsing
    final int sec = sopts.get(StaticOptions.PARSERESTXQ);
    // < 0: process until cache is invalidated
    if(sec >= 0) {
      // speed up permission checks: keep cache for a minimum of time even if caching is disabled
      final int ms = sec == 0 ? 10 : sec * 1000;
      new Timer(true).scheduleAtFixedRate(new TimerTask() {
        @Override
        public void run() {
          synchronized(WebModules.this) {
            if(System.currentTimeMillis() - access >= ms) init(true);
          }
        }
      }, 0, 100);
    }
  }

  /**
   * Returns the singleton instance.
   * @param ctx database context
   * @return instance
   */
  public static WebModules get(final Context ctx) {
    if(instance == null) instance = new WebModules(ctx);
    return instance;
  }

  /**
   * Initializes the module cache.
   * @param update only update new modules
   */
  public synchronized void init(final boolean update) {
    if(!update) modules = new HashMap<>();
    parsed = false;