Program Listing for File chain.hpp
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#ifndef MESSAGE_FILTERS__CHAIN_HPP_
#define MESSAGE_FILTERS__CHAIN_HPP_
#include <vector>
#include <memory>
#include "message_filters/simple_filter.hpp"
#include "message_filters/pass_through.hpp"
namespace message_filters
{
class ChainBase
{
public:
virtual ~ChainBase() {}
template<typename F>
std::shared_ptr<F> getFilter(size_t index) const
{
std::shared_ptr<void> filter = getFilterForIndex(index);
if (filter) {
return std::static_pointer_cast<F>(filter);
}
return std::shared_ptr<F>();
}
protected:
virtual std::shared_ptr<void> getFilterForIndex(size_t index) const = 0;
};
typedef std::shared_ptr<ChainBase> ChainBasePtr;
template<typename M>
class Chain : public ChainBase, public SimpleFilter<M>
{
public:
typedef std::shared_ptr<M const> MConstPtr;
typedef MessageEvent<M const> EventType;
Chain()
{
}
template<typename F>
explicit Chain(F & f)
{
connectInput(f);
}
struct NullDeleter
{
void operator()(void const *) const
{
}
};
template<class F>
size_t addFilter(F * filter)
{
std::shared_ptr<F> ptr(filter, NullDeleter());
return addFilter(ptr);
}
template<class F>
size_t addFilter(const std::shared_ptr<F> & filter)
{
FilterInfo info;
info.add_func = std::bind(
(void (F::*)(const EventType &)) & F::add, filter.get(), std::placeholders::_1);
info.filter = filter;
info.passthrough = std::make_shared<PassThrough<M>>();
last_filter_connection_.disconnect();
info.passthrough->connectInput(*filter);
last_filter_connection_ = info.passthrough->registerCallback(
typename SimpleFilter<M>::EventCallback(
std::bind(&Chain::lastFilterCB, this, std::placeholders::_1)));
if (!filters_.empty()) {
filter->connectInput(*filters_.back().passthrough);
}
size_t count = filters_.size();
filters_.push_back(info);
return count;
}
template<typename F>
std::shared_ptr<F> getFilter(size_t index) const
{
if (index >= filters_.size()) {
return std::shared_ptr<F>();
}
return std::static_pointer_cast<F>(filters_[index].filter);
}
template<class F>
void connectInput(F & f)
{
incoming_connection_.disconnect();
incoming_connection_ = f.registerCallback(
typename SimpleFilter<M>::EventCallback(
std::bind(&Chain::incomingCB, this, std::placeholders::_1)));
}
void add(const MConstPtr & msg)
{
add(EventType(msg));
}
void add(const EventType & evt)
{
if (!filters_.empty()) {
filters_[0].add_func(evt);
}
}
protected:
virtual std::shared_ptr<void> getFilterForIndex(size_t index) const
{
if (index >= filters_.size()) {
return std::shared_ptr<void>();
}
return filters_[index].filter;
}
private:
void incomingCB(const EventType & evt)
{
add(evt);
}
void lastFilterCB(const EventType & evt)
{
this->signalMessage(evt);
}
struct FilterInfo
{
std::function<void(const EventType &)> add_func;
std::shared_ptr<void> filter;
std::shared_ptr<PassThrough<M>> passthrough;
};
typedef std::vector<FilterInfo> V_FilterInfo;
V_FilterInfo filters_;
Connection incoming_connection_;
Connection last_filter_connection_;
};
} // namespace message_filters
#endif // MESSAGE_FILTERS__CHAIN_HPP_