getlineWithTimeout.h

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#ifndef __getlineWithTimeout_h__
#define __getlineWithTimeout_h__
#include <unwindCheck.h>
#include <condition_variable>
#include <mutex>
#include <thread>
 
 
class getlineWithTimeout : private unwindCheck {
    std::istream& stream;
    char delimiter;
    bool waitingForData;
    std::string line;
    std::mutex lineMutex;
    std::condition_variable cv;
    std::thread readerThread;
    bool running;
    void reader() {
        running = true;
        while (stream) {
            std::unique_lock<decltype(lineMutex)> lock(lineMutex);
            while (!waitingForData) {
                cv.wait(lock);
            }
            std::getline(stream, line, delimiter);
            waitingForData = false;
            cv.notify_all();
        }
        cv.notify_all();
        running = false;
    }
  public:
    getlineWithTimeout(std::istream& aStream,
                       char aDelimiter) :
        stream(aStream), delimiter(aDelimiter), waitingForData(true) {
        running = true;
        readerThread = std::thread(&getlineWithTimeout::reader, this);
    };
    ~getlineWithTimeout() {
        if (!isUnwinding()) {
            readerThread.join();
        }
    };
 
    bool active() {
        return running;
    }
 
    class nocopyLine {
        getlineWithTimeout& lineGetter;
        std::unique_lock<decltype(getlineWithTimeout::lineMutex)> lock;
      public:
        template <typename durationType> nocopyLine(getlineWithTimeout& aLineGetter, durationType timeout):
            lineGetter(aLineGetter), lock(lineGetter.lineMutex) {
            while (lineGetter.waitingForData) {
                if (lineGetter.cv.wait_for(lock, timeout) == std::cv_status::timeout) {
                    return;
                }
            }
            return;
        }
        bool timedOut() const {
            return lineGetter.waitingForData;
        }
        std::string& line() {
            return lineGetter.line;
        }
        ~nocopyLine() {
            lineGetter.waitingForData = true;
            lineGetter.cv.notify_all();
        }
    };
};
 
 
 
#endif