C

Cancel HTTP Get Async Task if not Completed after a Max Time

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Demonstrates how to wait a maximum amount of time for an asynchronous task to completed. If not completed in the allotted amount of time, the task is cancelled. C

#include <C_CkHttp.h>
#include <C_CkTask.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkHttp http;
    const char *url;
    HCkTask task;
    int waitMaxMs;
    BOOL wasCanceled;
    const char *responseStr;

    success = FALSE;

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

    http = CkHttp_Create();

    // Set some timeouts, in seconds:
    CkHttp_putConnectTimeout(http,15);
    // ReadTimeout specifies the max number of seconds that must elapse when no additional data is received before
    // timing out.  For example, if a server sends a 300 byte response at the rate of 1 byte per second, then
    // ReadTimeout would never cause a timeout because there is never a 15 second interval when nothing arrives.
    CkHttp_putReadTimeout(http,15);

    url = "https://your-url.com/something";
    task = CkHttp_QuickGetStrAsync(http,url);
    CkTask_Run(task);

    // Wait a maximum of waitMaxMs for the task (i.e. the HTTP GET) to complete.
    // The Wait method returns when the task has been canceled, aborted, or completed, or when the max allotted time has passed.
    waitMaxMs = 20000;
    CkTask_Wait(task,waitMaxMs);

    // At this point, the GET may or may not have completed.  
    // Rather than checking the Task status, we can call task.Cancel because
    // if the Task is no longer running (because it already completed, was canceled or aborted), then the 
    // call to Cancel is a NO-OP (meaning it does nothing and the Task's status is unaffected).
    // Also, task.Cancel returns TRUE if the task was in the "queued" or "running" state and was canceled or aborted. 
    // The method returns FALSE if the task has any other status.
    wasCanceled = CkTask_Cancel(task);
    if (wasCanceled == TRUE) {
        printf("The HTTP GET took too long and was canceled.\n");
    }
    else {
        // Find out what happened.
        if (CkTask_getStatusInt(task) == 7) {
            // The task completed, which means the background thread's call to QuickGetStr completed
            // with success or failure.  Find out which...
            if (CkTask_getTaskSuccess(task) == TRUE) {
                // Get the string response for the call to QuickGetStr (which happened in Chilkat's background thread).
                responseStr = CkTask_getResultString(task);
                printf("%s\n",responseStr);
                printf("HTTP GET successful!\n");
            }
            else {
                printf("HTTP GET failed prior to waitMaxMs...\n");
                printf("%s\n",CkTask_resultErrorText(task));
            }

        }
        else {
            // The task must've been canceled or aborted by some other means..
            printf("Task did not complete.  Final status: %s\n",CkTask_status(task));
        }

    }

    CkTask_Dispose(task);


    CkHttp_Dispose(http);

    }