Einen JSON-Stream mit boost :: asio lesen, vollständige Zeichenfolge abrufen?

Question

Ich lese einen TCP-Stream mit Boost. Der Strom ist in diesem Format.

"{\"animationValues\":{\"mouth_rightMouth_stretch\":0.0000000000000000,\"mouth_leftMouth_narrow\":0.00000000000000000,\"mouth_up\":0.0000000000000000,\"mouth_leftMouth_stretch\":0.0000000000000000,\"mouth_rightMouth_narrow\":0.00000000000000000,\"mouth_down\":0.00000000000000000,\"mouth_upperLip_left_up\":0.0000000000000000,\"mouth_upperLip_right_up\":0.0000000000000000,\"mouth_lowerLip_left_down\":0.0000000000000000,\"mouth_lowerLip_right_down\":0.0000000000000000,\"mouth_leftMouth_frown\":0.0000000000000000,\"mouth_rightMouth_frown\":0.0000000000000000,\"mouth_leftMouth_smile\":0.00000000000000000,\"mouth_rightMouth_smile\":0.00000000000000000,\"eyes_lookRight\":0.0000000000000000,\"eyes_lookLeft\":0.00000000000000000,\"eyes_lookDown\":0.0000000000000000,\"eyes_lookUp\":0.00000000000000000,\"eyes_leftEye_blink\":0.00000000000000000,\"eyes_rightEye_blink\":0.00000000000000000,\"eyes_leftEye_wide\":0.0000000000000000,\"eyes_rightEye_wide\":0.0000000000000000,\"brows_leftBrow_up\":0.0000000000000000,\"brows_leftBrow_down\":0.00000000000000000,\"brows_rightBrow_up\":0.0000000000000000,\"brows_rightBrow_down\":0.00000000000000000,\"brows_midBrows_up\":0.0000000000000000,\"brows_midBrows_down\":0.00000000000000000,\"jaw_open\":0.0000000000000000,\"jaw_left\":0.0000000000000000,\"jaw_right\":0.00000000000000000,\"mouth_phoneme_oo\":0.0000000000000000,\"mouth_right\":0.0000000000000000,\"mouth_left\":0.00000000000000000,\"mouth_phoneme_mbp\":0.0000000000000000,\"mouth_phoneme_ch\":0.0000000000000000},\"headRot\":[0.0,0.0, 0.0]}"; 

Ich versuche, diese zu lesen und jede Zeichenfolge zu analysieren, wie es kommt Also, was ich tun muß, um den Strom in Abschnitte aufgeteilt, die wie die oben schauen. Ich habe versucht:

boost::system::error_code error; 
    boost::asio::streambuf buffer; 
    boost::asio::read_until(sock, buffer, "]}"", error); 
    std::istream str(&buffer); 

aber das gibt mir nur die Hälfte der Zeichenfolge, die ich brauche. Ich habe versucht:

boost::array<char, 2046> buf; 
size_t len = sock.read_some(boost::asio::buffer(buf), error); 
std::string data(buf.begin(), buf.end()); 

aber das gibt mir noch weniger. Wie kann ich jeweils einen Abschnitt des Streams lesen? Vielen Dank.

Answer 1

Ja, ich würde read_until oder irgendeine der boost::asio::read_*-Familie verwenden, weil sie Lesevorgänge zusammensetzen (in Verbindung mit read_some).

Hier ist ein POC dieser Arbeits:

Live On Coliru

#include <boost/asio.hpp> 
#include <iostream> 

int main() 
{ 
    using namespace boost::asio; 
    using ip::tcp; 

    io_service io; 
    tcp::acceptor a(io, { {}, 6768 }); 
    a.listen(5); 

    tcp::socket s(io); 
    a.accept(s); 

    streambuf sb; 
    boost::system::error_code ec; 
    read_until(s, sb, "]}", ec); 

    std::cout << "Response: " << ec.message() << "\n"; 
    std::cout << "'" << &sb << "'\n"; 
} 

Wie Sie sehen können, wenn

{"animationValues": {"mouth_rightMouth_stretch": 0,"mouth_leftMouth_narrow": 0,"mouth_up": 0,"mouth_leftMouth_stretch": 0,"mouth_rightMouth_narrow": 0,"mouth_down": 0,"mouth_upperLip_left_up": 0,"mouth_upperLip_right_up": 0,"mouth_lowerLip_left_down": 0,"mouth_lowerLip_right_down": 0,"mouth_leftMouth_frown": 0,"mouth_rightMouth_frown": 0,"mouth_leftMouth_smile": 0,"mouth_rightMouth_smile": 0,"eyes_lookRight": 0,"eyes_lookLeft": 0,"eyes_lookDown": 0,"eyes_lookUp": 0,"eyes_leftEye_blink": 0,"eyes_rightEye_blink": 0,"eyes_leftEye_wide": 0,"eyes_rightEye_wide": 0,"brows_leftBrow_up": 0,"brows_leftBrow_down": 0,"brows_rightBrow_up": 0,"brows_rightBrow_down": 0,"brows_midBrows_up": 0,"brows_midBrows_down": 0,"jaw_open": 0,"jaw_left": 0,"jaw_right": 0,"mouth_phoneme_oo": 0,"mouth_right": 0,"mouth_left": 0,"mouth_phoneme_mbp": 0,"mouth_phoneme_ch": 0},"headRot": [0, 0, 0]} 
{"animationValues": {"mouth_rightMouth_stretch": 1,"mouth_leftMouth_narrow": 1,"mouth_up": 1,"mouth_leftMouth_stretch": 1,"mouth_rightMouth_narrow": 1,"mouth_down": 1,"mouth_upperLip_left_up": 1,"mouth_upperLip_right_up": 1,"mouth_lowerLip_left_down": 1,"mouth_lowerLip_right_down": 1,"mouth_leftMouth_frown": 1,"mouth_rightMouth_frown": 1,"mouth_leftMouth_smile": 1,"mouth_rightMouth_smile": 1,"eyes_lookRight": 1,"eyes_lookLeft": 1,"eyes_lookDown": 1,"eyes_lookUp": 1,"eyes_leftEye_blink": 1,"eyes_rightEye_blink": 1,"eyes_leftEye_wide": 1,"eyes_rightEye_wide": 1,"brows_leftBrow_up": 1,"brows_leftBrow_down": 1,"brows_rightBrow_up": 1,"brows_rightBrow_down": 1,"brows_midBrows_up": 1,"brows_midBrows_down": 1,"jaw_open": 1,"jaw_left": 1,"jaw_right": 1,"mouth_phoneme_oo": 1,"mouth_right": 1,"mouth_left": 1,"mouth_phoneme_mbp": 1,"mouth_phoneme_ch": 1},"headRot": [1, 1, 1]} 
{"animationValues": {"mouth_rightMouth_stretch": 2,"mouth_leftMouth_narrow": 2,"mouth_up": 2,"mouth_leftMouth_stretch": 2,"mouth_rightMouth_narrow": 2,"mouth_down": 2,"mouth_upperLip_left_up": 2,"mouth_upperLip_right_up": 2,"mouth_lowerLip_left_down": 2,"mouth_lowerLip_right_down": 2,"mouth_leftMouth_frown": 2,"mouth_rightMouth_frown": 2,"mouth_leftMouth_smile": 2,"mouth_rightMouth_smile": 2,"eyes_lookRight": 2,"eyes_lookLeft": 2,"eyes_lookDown": 2,"eyes_lookUp": 2,"eyes_leftEye_blink": 2,"eyes_rightEye_blink": 2,"eyes_leftEye_wide": 2,"eyes_rightEye_wide": 2,"brows_leftBrow_up": 2,"brows_leftBrow_down": 2,"brows_rightBrow_up": 2,"brows_rightBrow_down": 2,"brows_midBrows_up": 2,"brows_midBrows_down": 2,"jaw_open": 2,"jaw_left": 2,"jaw_right": 2,"mouth_phoneme_oo": 2,"mouth_right": 2,"mouth_left": 2,"mouth_phoneme_mbp": 2,"mouth_phoneme_ch": 2},"headRot": [2, 2, 2]} 

Senden Sie druckt:

Response: Success 
'{"animationValues": {"mouth_rightMouth_stretch": 0,"mouth_leftMouth_narrow": 0,"mouth_up": 0,"mouth_leftMouth_stretch": 0,"mouth_rightMouth_narrow": 0,"mouth_down": 0,"mouth_upperLip_left_up": 0,"mouth_upperLip_right_up": 0,"mouth_lowerLip_left_down": 0,"mouth_lowerLip_right_down": 0,"mouth_leftMouth_frown": 0,"mouth_rightMouth_frown": 0,"mouth_leftMouth_smile": 0,"mouth_rightMouth_smile": 0,"eyes_lookRight": 0,"eyes_lookLeft": 0,"eyes_lookDown": 0,"eyes_lookUp": 0,"eyes_leftEye_blink": 0,"eyes_rightEye_blink": 0,"eyes_leftEye_wide": 0,"eyes_rightEye_wide": 0,"brows_leftBrow_up": 0,"brows_leftBrow_down": 0,"brows_rightBrow_up": 0,"brows_rightBrow_down": 0,"brows_midBrows_up": 0,"brows_midBrows_down": 0,"jaw_open": 0,"jaw_left": 0,"jaw_right": 0,"mouth_phoneme_oo": 0,"mouth_right": 0,"mouth_left": 0,"mouth_phoneme_mbp": 0,"mouth_phoneme_ch": 0},"headRot": [0, 0, 0]} 
{"animationValues": {"mouth_rightMouth_stretch": 1,"mouth_leftMouth_narrow": 1,"mouth_up": 1,"mouth_leftMouth_stretch": 1,"mouth_rightMouth_narrow' 

Dinge bewusst sein:

1. sicherstellen, dass die Formatierung tatsächlich so ist, dass ]} auftritt. Das bedeutet, dass ziemlich druckten json nicht erkannt wird:

    "mouth_phoneme_mbp": 2, 
        "mouth_phoneme_ch": 2 
       }, 
       "headRot": [2, 2, 2] 
   } 
   

2. auch sicherstellen, dass Sie sich der Tatsache bewusst sind, dass read_until einen Puffer zurückgeben kann, die mehr Daten enthält (es zurück, sobald der Begrenzer zufrieden, aber möglicherweise wurden mehr Daten gelesen)