websocket-driver-ruby/ext/websocket-driver/WebsocketMaskService.java

package com.jcoglan.websocket;

import java.lang.Long;
import java.io.IOException;

import org.jruby.Ruby;
import org.jruby.RubyArray;
import org.jruby.RubyClass;
import org.jruby.RubyFixnum;
import org.jruby.RubyModule;
import org.jruby.RubyObject;
import org.jruby.anno.JRubyMethod;
import org.jruby.runtime.ObjectAllocator;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.runtime.load.BasicLibraryService;

public class WebsocketMaskService implements BasicLibraryService {
  private Ruby runtime;

  public boolean basicLoad(Ruby runtime) throws IOException {
    this.runtime = runtime;
    RubyModule websocket = runtime.defineModule("WebSocket");

    RubyClass webSocketMask = websocket.defineClassUnder("Mask", runtime.getObject(), new ObjectAllocator() {
      public IRubyObject allocate(Ruby runtime, RubyClass rubyClass) {
        return new WebsocketMask(runtime, rubyClass);
      }
    });

    webSocketMask.defineAnnotatedMethods(WebsocketMask.class);
    return true;
  }

  public class WebsocketMask extends RubyObject {
    public WebsocketMask(final Ruby runtime, RubyClass rubyClass) {
      super(runtime, rubyClass);
    }

    @JRubyMethod
    public IRubyObject mask(ThreadContext context, IRubyObject payload, IRubyObject mask) {
      if (mask.isNil() || ((RubyArray)mask).getLength() == 0) {
        return payload;
      }

      int n = ((RubyArray)payload).getLength(), i;
      long p, m;
      RubyArray unmasked = RubyArray.newArray(runtime, n);

      long[] maskArray = {
        (Long)((RubyArray)mask).get(0),
        (Long)((RubyArray)mask).get(1),
        (Long)((RubyArray)mask).get(2),
        (Long)((RubyArray)mask).get(3)
      };

      for (i = 0; i < n; i++) {
        p = (Long)((RubyArray)payload).get(i);
        m = maskArray[i % 4];
        unmasked.set(i, p ^ m);
      }
      return unmasked;
    }
  }
}