(C) Read Bitfinex WebSocket Ticker Channel

Subscribes to the public Bitfinex websocket ticker channel and receives ticker updates.

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

#include <C_CkWebSocket.h>
#include <C_CkRest.h>
#include <C_CkJsonObject.h>

void ChilkatSample(void)
    {
    HCkWebSocket ws;
    HCkRest rest;
    BOOL success;
    const char *responseBody;
    HCkJsonObject json;
    BOOL finalFrame;
    BOOL receivedFinalFrame;
    int numUpdatesReceived;
    const char *receivedText;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    ws = CkWebSocket_Create();

    //  For brevity, this example does not check for errors when etablishing the WebSocket connection.
    //  See Establish WebSocket Connection for more complete sample code for making the connection.

    rest = CkRest_Create();

    //  Connect to api.bitfinex.com
    success = CkRest_Connect(rest,"api.bitfinex.com",443,TRUE,FALSE);
    CkWebSocket_UseConnection(ws,rest);
    CkWebSocket_AddClientHeaders(ws);

    responseBody = CkRest_fullRequestNoBody(rest,"GET","/ws");
    success = CkWebSocket_ValidateServerHandshake(ws);
    if (success != TRUE) {
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        printf("%s\n",responseBody);
        printf("%s\n",CkRest_responseHeader(rest));
        CkWebSocket_Dispose(ws);
        CkRest_Dispose(rest);
        return;
    }

    //  After connecting, the bitfinex websocket server will send
    //  an info message that contains the actual version of the websocket stream.
    //  Receive that message..
    success = CkWebSocket_ReadFrame(ws);
    if (success != TRUE) {
        printf("Failed to receive a frame\n");
        printf("ReadFrame fail reason = %d\n",CkWebSocket_getReadFrameFailReason(ws));
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkWebSocket_Dispose(ws);
        CkRest_Dispose(rest);
        return;
    }

    //  We should get this:
    //  {"event":"info","version":1.1,"platform":{"status":1}}
    printf("%s\n",CkWebSocket_getFrameData(ws));

    //  Subscribe to the public ticker feed.
    //  See https://docs.bitfinex.com/docs for more information.
    json = CkJsonObject_Create();
    CkJsonObject_AppendString(json,"event","subscribe");
    CkJsonObject_AppendString(json,"channel","ticker");
    CkJsonObject_AppendString(json,"pair","BTCUSD");

    finalFrame = TRUE;
    success = CkWebSocket_SendFrame(ws,CkJsonObject_emit(json),finalFrame);

    //  Read the response.
    success = CkWebSocket_ReadFrame(ws);
    if (success != TRUE) {
        printf("Failed to receive a frame\n");
        printf("ReadFrame fail reason = %d\n",CkWebSocket_getReadFrameFailReason(ws));
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkWebSocket_Dispose(ws);
        CkRest_Dispose(rest);
        CkJsonObject_Dispose(json);
        return;
    }

    //  Examine the response
    //  We should get this:
    //  {"event":"subscribed","channel":"ticker","chanId":2751,"pair":"BTCUSD"}
    printf("%s\n",CkWebSocket_getFrameData(ws));

    //  Begin reading the ticker feed.
    //  We'll just read the 1st 5 updates and then exit..
    receivedFinalFrame = FALSE;
    numUpdatesReceived = 0;
    while (numUpdatesReceived < 5) {

        success = CkWebSocket_ReadFrame(ws);
        if (success != TRUE) {
            printf("Failed to receive a frame\n");
            printf("ReadFrame fail reason = %d\n",CkWebSocket_getReadFrameFailReason(ws));
            printf("%s\n",CkWebSocket_lastErrorText(ws));
            CkWebSocket_Dispose(ws);
            CkRest_Dispose(rest);
            CkJsonObject_Dispose(json);
            return;
        }

        //  The responses we desire are in Text frames, where the opcode = 1.
        if (CkWebSocket_getFrameOpcodeInt(ws) == 1) {
            receivedText = CkWebSocket_getFrameData(ws);
            printf("%s\n",receivedText);
            //  Should receive a line of text such as this:
            //  [2751,7349,36.34269559,7349.1,41.01777063,-116.2,-0.0156,7349.1,22188.26055319,7560,7270.5]
            numUpdatesReceived = numUpdatesReceived + 1;
        }

    }

    //  Close the websocket connection.
    success = CkWebSocket_SendClose(ws,TRUE,1000,"Closing this websocket.");
    if (success != TRUE) {
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkWebSocket_Dispose(ws);
        CkRest_Dispose(rest);
        CkJsonObject_Dispose(json);
        return;
    }

    //  Read the Close response.
    success = CkWebSocket_ReadFrame(ws);
    if (success != TRUE) {
        printf("ReadFrame fail reason = %d\n",CkWebSocket_getReadFrameFailReason(ws));
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkWebSocket_Dispose(ws);
        CkRest_Dispose(rest);
        CkJsonObject_Dispose(json);
        return;
    }

    printf("Success.\n");


    CkWebSocket_Dispose(ws);
    CkRest_Dispose(rest);
    CkJsonObject_Dispose(json);

    }