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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MOJO_SYSTEM_MESSAGE_QUEUE_H_
#define MOJO_SYSTEM_MESSAGE_QUEUE_H_
#include <deque>
#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "mojo/system/message_in_transit.h"
#include "mojo/system/system_impl_export.h"
namespace mojo {
namespace system {
// A simple queue for |MessageInTransit|s (that owns its messages).
// This class is not thread-safe.
// TODO(vtl): Write tests.
class MOJO_SYSTEM_IMPL_EXPORT MessageInTransitQueue {
public:
MessageInTransitQueue();
struct PassContents {};
// Constructor that takes over the contents of another
// |MessageInTransitQueue|, leaving it empty.
MessageInTransitQueue(PassContents, MessageInTransitQueue* other);
~MessageInTransitQueue();
bool IsEmpty() const {
return queue_.empty();
}
void AddMessage(scoped_ptr<MessageInTransit> message) {
queue_.push_back(message.release());
}
scoped_ptr<MessageInTransit> GetMessage() {
MessageInTransit* rv = queue_.front();
queue_.pop_front();
return make_scoped_ptr(rv);
}
MessageInTransit* PeekMessage() {
return queue_.front();
}
void DiscardMessage() {
delete queue_.front();
queue_.pop_front();
}
void Clear();
private:
// TODO(vtl): When C++11 is available, switch this to a deque of
// |scoped_ptr|/|unique_ptr|s.
std::deque<MessageInTransit*> queue_;
DISALLOW_COPY_AND_ASSIGN(MessageInTransitQueue);
};
} // namespace system
} // namespace mojo
#endif // MOJO_SYSTEM_MESSAGE_QUEUE_H_