pagespeed/kernel/thread/blocking_callback.h

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#ifndef PAGESPEED_KERNEL_THREAD_BLOCKING_CALLBACK_H_
#define PAGESPEED_KERNEL_THREAD_BLOCKING_CALLBACK_H_

#include "pagespeed/kernel/base/cache_interface.h"
#include "pagespeed/kernel/base/shared_string.h"
#include "pagespeed/kernel/base/string.h"
#include "pagespeed/kernel/base/string_util.h"
#include "pagespeed/kernel/base/thread_system.h"
#include "pagespeed/kernel/thread/worker_test_base.h"

namespace net_instaweb {

// Helper that blocks for async cache lookups. Used in tests.
class BlockingCallback : public CacheInterface::Callback {
 public:
  explicit BlockingCallback(ThreadSystem* threads)
      : sync_(threads), result_(CacheInterface::kNotFound) {}

  CacheInterface::KeyState result() const { return result_; }
  GoogleString value() const { return value_; }

  void Block() {
    sync_.Wait();
  }

 protected:
  virtual void Done(CacheInterface::KeyState state) {
    result_ = state;
    CacheInterface::Callback::value().Value().CopyToString(&value_);
    sync_.Notify();
  }

 private:
  WorkerTestBase::SyncPoint sync_;
  CacheInterface::KeyState result_;
  GoogleString value_;
};

}  // namespace net_instaweb

#endif  // PAGESPEED_KERNEL_THREAD_BLOCKING_CALLBACK_H_