private static void persistentWorkerMain()

in src/java/io/bazel/rulesscala/worker/Worker.java [46:113]
52 lines of code
7 McCabe index (conditional complexity)

  private static void persistentWorkerMain(Interface workerInterface) {
    System.setSecurityManager(
        new SecurityManager() {
          @Override
          public void checkPermission(Permission permission) {
            Matcher matcher = exitPattern.matcher(permission.getName());
            if (matcher.find()) throw new ExitTrapped(Integer.parseInt(matcher.group(1)));
          }
        });

    InputStream stdin = System.in;
    PrintStream stdout = System.out;
    PrintStream stderr = System.err;
    ByteArrayOutputStream outStream = new SmartByteArrayOutputStream();
    PrintStream out = new PrintStream(outStream);

    // We can't support stdin, so assign it to read from an empty buffer
    System.setIn(new ByteArrayInputStream(new byte[0]));

    System.setOut(out);
    System.setErr(out);

    try {
      while (true) {
        try {
          WorkerProtocol.WorkRequest request = WorkerProtocol.WorkRequest.parseDelimitedFrom(stdin);

          // The request will be null if stdin is closed.  We're
          // not sure if this happens in TheRealWorld™ but it is
          // useful for testing (to shut down a persistent
          // worker process).
          if (request == null) {
            break;
          }

          int code = 0;

          try {
            workerInterface.work(stringListToArray(request.getArgumentsList()));
          } catch (ExitTrapped e) {
            code = e.code;
          } catch (Exception e) {
            System.err.println(e.getMessage());
            e.printStackTrace();
            code = 1;
          }

          WorkerProtocol.WorkResponse.newBuilder()
              .setExitCode(code)
              .setOutput(outStream.toString())
              .build()
              .writeDelimitedTo(stdout);

        } catch (IOException e) {
          // for now we swallow IOExceptions when
          // reading/writing proto
        } finally {
          out.flush();
          outStream.reset();
          System.gc();
        }
      }
    } finally {
      System.setIn(stdin);
      System.setOut(stdout);
      System.setErr(stderr);
    }
  }