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HCCallPerformFunction

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Syntax

void CALLBACK HCCallPerformFunction(
         HCCallHandle call,
         XAsyncBlock* asyncBlock,
         void* context,
         HCPerformEnv env
)

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Parameters

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Return value

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Remarks

1. Read the request with the HCHttpCallRequestGet* functions, such as HCHttpCallRequestGetUrl, HCHttpCallRequestGetNumHeaders, HCHttpCallRequestGetHeaderAtIndex, and HCHttpCallRequestGetRequestBodyReadFunction.
2. Send the request with your HTTP stack. Return from the callback promptly and do the network work asynchronously.
3. Set the response with the HCHttpCallResponseSet* functions, such as HCHttpCallResponseSetStatusCode and HCHttpCallResponseSetHeader. Write the response body through the function returned by HCHttpCallResponseGetResponseBodyWriteFunction.
4. If a network error occurs, call HCHttpCallResponseSetNetworkErrorCode.
5. Call XAsyncComplete(asyncBlock, S_OK, 0) to finish the attempt, including when you reported a network error in step 4. libHttpClient decides whether to retry from the network error and status code that you set on the response. Complete with a failure HRESULT only if your provider itself fails internally. Doing so skips automatic retry and fails the call to HCHttpCallPerformAsync with that HRESULT.

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Example

static HCCallPerformFunction g_defaultPerform = nullptr;
static void* g_defaultContext = nullptr;

void CALLBACK LoggingPerform(
    HCCallHandle call,
    XAsyncBlock* asyncBlock,
    void* /*context*/,
    HCPerformEnv env)
{
    const char* method = nullptr;
    const char* url = nullptr;
    if (SUCCEEDED(HCHttpCallRequestGetUrl(call, &method, &url)))
    {
        // Log method and url.
    }

    g_defaultPerform(call, asyncBlock, g_defaultContext, env);
}

// Before calling HCInitialize:
HRESULT hr = HCGetHttpCallPerformFunction(&g_defaultPerform, &g_defaultContext);
if (SUCCEEDED(hr))
{
    hr = HCSetHttpCallPerformFunction(LoggingPerform, nullptr);
}

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Requirements

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See also