reader.h
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00001 #ifndef H_CAN_BUFFERED_READER
00002 #define H_CAN_BUFFERED_READER
00003 
00004 #include <socketcan_interface/interface.h>
00005 #include <deque>
00006 
00007 #include <boost/thread/mutex.hpp>
00008 #include <boost/thread/condition_variable.hpp>
00009 #include <boost/chrono.hpp>
00010 
00011 namespace can{
00012 
00013 class BufferedReader {
00014     std::deque<can::Frame> buffer_;
00015     boost::mutex mutex_;
00016     boost::condition_variable cond_;
00017     CommInterface::FrameListener::Ptr listener_;
00018     bool enabled_;
00019     size_t max_len_;
00020 
00021     void trim(){
00022         if(max_len_ > 0){
00023             while(buffer_.size() > max_len_){
00024                 LOG("buffer overflow, discarded oldest message " /*<< tostring(buffer_.front())*/); // enable message printing
00025                 buffer_.pop_front();
00026             }
00027         }
00028     }
00029     void handleFrame(const can::Frame & msg){
00030         boost::mutex::scoped_lock lock(mutex_);
00031         if(enabled_){
00032             buffer_.push_back(msg);
00033             trim();
00034             cond_.notify_one();
00035         }else{
00036             LOG("discarded message " /*<< tostring(msg)*/); // enable message printing
00037         }
00038     }
00039 public:
00040     class ScopedEnabler{
00041         BufferedReader &reader_;
00042         bool before_;
00043     public:
00044         ScopedEnabler(BufferedReader &reader) : reader_(reader), before_(reader_.setEnabled(true)) {}
00045         ~ScopedEnabler() { reader_.setEnabled(before_); }
00046     };
00047 
00048     BufferedReader() : enabled_(true), max_len_(0) {}
00049     BufferedReader(bool enable, size_t max_len = 0) : enabled_(enable), max_len_(max_len) {}
00050 
00051     void flush(){
00052         boost::mutex::scoped_lock lock(mutex_);
00053         buffer_.clear();
00054     }
00055     void setMaxLen(size_t max_len){
00056         boost::mutex::scoped_lock lock(mutex_);
00057         max_len_ = max_len;
00058         trim();
00059     }
00060     bool isEnabled(){
00061         boost::mutex::scoped_lock lock(mutex_);
00062         return enabled_;
00063     }
00064     bool setEnabled(bool enabled){
00065         boost::mutex::scoped_lock lock(mutex_);
00066         bool  before = enabled_;
00067         enabled_ = enabled;
00068         return before;
00069     }
00070     void enable(){
00071         boost::mutex::scoped_lock lock(mutex_);
00072         enabled_ = true;
00073     }
00074 
00075     void disable(){
00076         boost::mutex::scoped_lock lock(mutex_);
00077         enabled_ = false;
00078     }
00079 
00080     void listen(boost::shared_ptr<CommInterface> interface){
00081         boost::mutex::scoped_lock lock(mutex_);
00082         listener_ = interface->createMsgListener(CommInterface::FrameDelegate(this, &BufferedReader::handleFrame));
00083         buffer_.clear();
00084     }
00085     void listen(boost::shared_ptr<CommInterface> interface, const Frame::Header& h){
00086         boost::mutex::scoped_lock lock(mutex_);
00087         listener_ = interface->createMsgListener(h, CommInterface::FrameDelegate(this, &BufferedReader::handleFrame));
00088         buffer_.clear();
00089     }
00090 
00091     template<typename DurationType> bool read(can::Frame * msg, const DurationType &duration){
00092         return readUntil(msg, boost::chrono::high_resolution_clock::now() + duration);
00093     }
00094     bool readUntil(can::Frame * msg, boost::chrono::high_resolution_clock::time_point abs_time){
00095         boost::mutex::scoped_lock lock(mutex_);
00096 
00097         while(buffer_.empty() && cond_.wait_until(lock,abs_time)  != boost::cv_status::timeout)
00098         {}
00099 
00100         if(buffer_.empty()){
00101             return false;
00102         }
00103 
00104         if(msg){
00105             *msg = buffer_.front();
00106             buffer_.pop_front();
00107         }
00108         return true;
00109     }
00110 
00111 };
00112 
00113 } // namespace can
00114 #endif


socketcan_interface
Author(s): Mathias L├╝dtke
autogenerated on Thu Jun 6 2019 20:43:53