ICacheProvider::GetTraceContext Method

Returns the trace context for the cache provider.

Syntax

virtual IHttpTraceContext* GetTraceContext(  
   VOID  
) const = 0;  

Parameters

This method takes no parameters.

Return Value

An IHttpTraceContext pointer.

Remarks

CGlobalModule derived classes that register for GL_CACHE_OPERATION events receive an ICacheProvider pointer as a parameter on the CGlobalModule::OnGlobalCacheOperationvirtual method. You can retrieve an IHttpTraceContext pointer by calling the GetTraceContext method on the ICacheProvider pointer.

Notes for Implementers

ICacheProvider implementers are responsible for memory management with this data; therefore, ICacheProvider implementers that use dynamic memory allocation must release or call delete on the IHttpTraceContext pointer when it is no longer needed.

Notes for Callers

ICacheProvider implementers are responsible for memory management with this data; therefore, ICacheProvider clients must not release or call delete on the returned IHttpTraceContext pointer when this data is no longer needed.

Example

The following code example demonstrates how to create a global module that listens for GL_CACHE_OPERATION and GL_CACHE_CLEANUP events and then writes the IHttpTraceContext information to the Event Viewer.

#pragma warning( disable : 4290 )
#pragma warning( disable : 4530 )

#define _WINSOCKAPI_
#include <windows.h>
#include <sal.h>
#include <tchar.h>
#include <initguid.h>
#include <httptrace.h>
#include <httpserv.h>
#include <httpcach.h>

#include <string>
using namespace std;

#import "msxml6.dll"
using namespace MSXML2;

// The CConvert class mirrors the Convert class that is 
// defined in the .NET Framework. It converts primitives 
// and other data types to wstring types.
class CConvert
{
public:
    // The ToString method converts a HANDLE to a wstring.
    // h: the HANDLE to convert to a wstring.
    // return: the HANDLE as a wstring.
    static wstring ToString(HANDLE h)
    {
        // If the HANDLE is NULL, return the "NULL" string.
        if (NULL == h)
        {
            return L"NULL";
        }

        // If the HANDLE is not valid, return 
        // the INVALID_HANDLE_VALUE as a string.
        if (INVALID_HANDLE_VALUE == h)
        {
            return L"INVALID_HANDLE_VALUE";
        }

        // The HANDLE is valid.
        return L"valid";
    }
    
    // The ToString method converts a FILETIME pointer to a wstring.
    // fileTime: the FILETIME pointer to convert to a wstring.
    // return: the FILETIME pointer as a wstring.
    static wstring ToString(FILETIME* fileTime)
    {
        // If fileTime is NULL, return the empty string.
        if (NULL == fileTime)
        {
            return L"NULL";
        }

        // Convert the FILETIME to a local time, and 
        // then convert that local time to a wstring.
        SYSTEMTIME stUTC;
        SYSTEMTIME stLocal;
        FileTimeToSystemTime(fileTime, &stUTC);
        SystemTimeToTzSpecificLocalTime(NULL, &stUTC, &stLocal);        

        // Create a wstring to return.  Note: wsprintf 
        // can be also used. However, it is more difficult 
        // to handle both UNICODE and non-UNICODE correctly.
        wstring timeString =
            ToString(stLocal.wMonth) +
            wstring(L"/")            +
            ToString(stLocal.wDay)   +
            wstring(L"/")            +
            ToString(stLocal.wYear)  +
            wstring(L"  ")           +
            ToString(stLocal.wHour)  +
            wstring(L":")            +
            ToString(stLocal.wMinute);

        // Return the FILETIME data as a wstring.
        return timeString;
    }
    
    // The ToString method converts a 
    // ULARGE_INTEGER pointer to a wstring.
    // ui: the ULARGE_INTEGER pointer to convert to a string.
    // return: the ULARGE_INTEGER pointer as a string.
    static wstring ToString(ULARGE_INTEGER* ui)
    {
        // Return the empty string if the 
        // ULARGE_INTEGER pointer is NULL.
        if (NULL == ui)
        {
            return L"NULL";
        }
        
        // Return the low-order part to a wstring.
        return (ToString(ui->LowPart));
    }
    
    // The ToString method converts a PCSTR to a wstring.
    // pcstr: the PCSTR to convert to a wstring.
    // return: the PCSTR as a wstring.
    static wstring ToString(PCSTR pcstr)
    {
        // Return the empty string 
        // if the PCSTR is NULL.
        if (NULL == pcstr)
        {
            return L"NULL";
        }

        // Get the length of the string to copy.
        size_t length = strlen(pcstr);
        // Create a new double-byte character 
        // array of length plus 1.
        wchar_t* newText = new wchar_t[length+1];

        // Copy the source into the sink string.
        for (size_t i = 0; i < length; ++i)
        {
            newText[i] = pcstr[i];
        }

        // Terminate the string with the NULL character.
        newText[length] = '\0';
        // Get a wstring from the new double-byte string.
        wstring wText = newText;
        // Call delete on the newText pointer 
        // and set this pointer to NULL.
        delete[] newText;
        newText = NULL;

        // Return the wstring copy.
        return wText;
    }
        
    // The ToString method converts a long to a wstring.
    // l: the long value to convert to a wstring.
    // return: the long as a wstring.
    static wstring ToString(long l)
    {
        WCHAR str[256];
        str[0] = '\0';        
        _ltow_s(l, str, 256, 10);
        return str;
    }
        
    // The ToString method converts a DWORD to a wstring.
    // d: the DWORD value to convert to a wstring.
    // return: the DWORD as a wstring.
    static wstring ToString(DWORD d)
    {
        return ToString((long)d);
    }
    
    // The ToString method converts an LPCGUID to a wstring.
    // guid: the LPCGUID value to convert to a wstring.
    // return: The LPCGUID as a wstring; otherwise, L"" if
    // guid is NULL.
    static wstring ToString(LPCGUID guid)
    {
        // If the GUID is NULL, return the empty string.
        if (NULL == guid)
        {
            return L"NULL";
        }

        // Create a WCHAR array to write the GUID to.
        WCHAR guidString[256];
        // Initialize the zero-based index of the 
        // guidString to the null-terminating character 
        // because the StringFromGUID2 may fail.
        guidString[0] = '\0';
        // Convert the GUID to a string of the form "{...}".
        int characters = StringFromGUID2(*guid, guidString, 256);
        // Return the guidString as a wstring.
        return guidString;
    }

    // The ToString method converts a BOOL to a wstring.
    // b: the BOOL value to convert to a wstring.
    // return: L"true" for true; otherwise, L"false" for false.
    static wstring ToString(BOOL b)
    {
        return (b) ? L"true" : L"false";
    }

    // The ToByteString converts a double-byte 
    // character string to a single-byte string.
    // str: the double-byte string to convert.
    // return: a single-byte string copied from str.
    static string ToByteString(const wstring& str)
    {
        // Get the length of the 
        // double-byte string.
        size_t length = str.length();

        // Create a temporary char pointer.
        char* byteChar = new char[length+1];
        byteChar[0] = '\0';
        // Copy the double-byte character string
        // into the single-byte string.        
        size_t charsReturned = 0;
        wcstombs_s(&charsReturned, byteChar, 
                   length+1, str.c_str(), length+1);
        // Create a string to return.
        string retString = byteChar;
        // Delete the temporary string and
        // set that string to NULL.
        delete[] byteChar;
        byteChar = NULL;

        // Return the single-byte string.
        return retString;
    }

    // The ToString method converts a USHORT to a wstring.
    // u: the USHORT value to convert to a wstring.
    // return: the value of u as a wstring.
    static wstring ToString(USHORT u)
    {
        return (ToString((long)u));
    }

    // The ToString method converts a 
    // const BYTE pointer to a wstring.
    // bytes: the BYTE pointer to convert.
    // return: the value of bytes as a wstring.
    static wstring ToString(const BYTE* bytes)
    {
        return (ToString((PCSTR)bytes));    
    }

    // The ToString method converts 
    // a PCWSTR to a wstring.
    // pcwstr: the PCWSTR to convert.
    // return: L"NULL" if the pcwstr
    // parameter is NULL; otherwise, 
    // pcwstr converted to a wstring.
    static wstring ToString(PCWSTR pcwstr)
    {
        // If the pcwstr parameter
        // is NULL, return L"NULL".
        if (NULL == pcwstr)
        {
            return L"NULL";
        }

        // Implicitly convert the 
        // PCWSTR to a wstring.
        return pcwstr;
    }

    // The ToString method converts 
    // a character to a wstring.
    // c: the character to convert.
    // return: c as a wstring.
    static wstring ToString(char c)
    {
        wstring str;
        str += c;
        return str;
    }

    // The ToString method converts
    // a short to a wstring.
    // s: the short to convert.
    // return: s as a wstring.
    static wstring ToString(short s)
    {
        return (ToString((long)s));
    }
};

// The CEventWriter class writes XML 
// documents and strings to the event log.
class CEventWriter
{
public:
    // Creates the CEventWriter class.
    // name: the name of the 
    // event log to open.
    CEventWriter(const wstring& name)
    {                
        #ifdef UNICODE
        m_eventLog = RegisterEventSource(NULL, name.c_str());
        #else
        string multiName = CConvert::ToByteString(name);
        m_eventLog = RegisterEventSource(NULL, multiName.c_str());
        #endif        
    }

    // Creates the destructor for the 
    // CEventWriter class. This destructor
    // closes the HANDLE to the event 
    // log if that HANDLE is open.
    virtual ~CEventWriter()
    {
        // If the HANDLE to the event 
        // log is open, close it.
        if (NULL != m_eventLog)
        {
            // Deregister the event log HANDLE.
            DeregisterEventSource(m_eventLog);
            // Set the HANDLE to NULL.
            m_eventLog = NULL;
        }
    }

    // The ReportInfo method writes the content
    // of the XML document to the event log.
    // doc: the XML document to write.
    // return: true if the event log is written.
    BOOL ReportInfo(MSXML2::IXMLDOMDocument3Ptr doc)
    {
        MSXML2::IXMLDOMElementPtr documentElement = 
            doc->documentElement;
        // Get the XML as a BSTR and place this XML into a 
        // _bstr_t wrapper. The client of the XML document 
        // is responsible for deleting the returned BSTR from 
        // the property, which the _bstr_t wrapper will do
        // automatically.
        _bstr_t bstrXml = documentElement->xml;
        // Convert the _bstr_t to a wstring.
        wstring xmlString = bstrXml;
        // Write the XML to the event writer.
        return ReportInfo(xmlString);        
    }

    // The ReportInfo method writes 
    // a wstring to the event log.
    // info: the wstring to write.
    // return: true if the event log is written.
    BOOL ReportInfo(const wstring& info)
    {
        return ReportEvent(EVENTLOG_INFORMATION_TYPE, info);
    }

    // The ReportError method writes 
    // a wstring to the event log.
    // error: the wstring to write.
    // return: true if the event log is written.
    BOOL ReportError(const wstring& error)
    {
        return ReportEvent(EVENTLOG_ERROR_TYPE, error);
    }
protected:
    // The ReportEvent method accepts an event type
    // and a wstring, and attempts to write that 
    // event to the event log.
    // type: the type of the event.
    // data: the wstring to write to the event log.
    // return: true if the event log is written;
    // otherwise, false.
    BOOL ReportEvent(WORD type, const wstring& data)
    {
        // If the m_eventLog HANDLE 
        // is NULL, return false.
        if (NULL == m_eventLog)
        {
            return FALSE;
        }

        #ifndef _DEBUG
        // If the current build is not debug,
        // return so the event log is not written.
        return TRUE;
        #endif

        #ifdef UNICODE
        // The unicode version of the ReportEvent
        // method requires double-byte strings.
        PCWSTR arr[1];
        arr[0] = data.c_str();
        return ::ReportEvent(m_eventLog,
                             type,
                             0, 0, NULL, 1, 
                             0, arr, (void*)arr);
        #else
        // The non-unicode version of the ReportEvent
        // method requires single-byte strings.
        string multiByte = 
            CConvert::ToByteString(data);
        LPCSTR arr[1];
        arr[0] = multiByte.c_str();
        return ::ReportEvent(m_eventLog,
                             type,
                             0, 0, NULL, 1,
                             0, arr, (void*)arr);
        #endif
    }
private:
    // Specify the HANDLE to the 
    // event log for writing.
    HANDLE m_eventLog;
};

// The CGlobalCacheModule class creates the CGlobalModule 
// class and registers for GL_CACHE_OPERATION and 
// GL_CACHE_CLEANUP events.
class CGlobalCacheModule : public CGlobalModule
{
public:
    // Creates the destructor for the 
    // CGlobalCacheModule class.
    virtual ~CGlobalCacheModule()
    {

    }

    // The RegisterGlobalModule method creates and registers 
    // a new CGlobalCacheModule for GL_CACHE_OPERATION and 
    // GL_CACHE_CLEANUP events.
    // dwServerVersion: the current server version.
    // pModuleInfo: the current IHttpModuleRegistrationInfo pointer.
    // pGlobalInfo: the current IHttpServer pointer.
    // return: ERROR_NOT_ENOUGH_MEMORY if the heap is out of 
    // memory; otherwise, the value from the call to the 
    // SetGlobalNotifications method on the pModuleInfo pointer.
    static HRESULT RegisterGlobalModule
    (
        DWORD dwServerVersion,
        IHttpModuleRegistrationInfo* pModuleInfo,
        IHttpServer* pGlobalInfo
    )
    {        
        // The pGlobalInfo parmeter must be non-NULL because
        // the constructor for the CGlobalCacheModule class
        // requires a non-NULL pointer to a valid IHttpServer 
        // pointer.
        if (NULL == pGlobalInfo)
        {
            return E_INVALIDARG;
        }

        // Create a new CGlobalCacheModule pointer.
        CGlobalCacheModule* traceModule = 
            new CGlobalCacheModule();

        // Return an out-of-memory error if the traceModule 
        // is NULL after the call to the new operator.
        if (NULL == traceModule)
        {            
            return HRESULT_FROM_WIN32(ERROR_NOT_ENOUGH_MEMORY);
        }        

        // Attempt to set global notification for both 
        // GL_CACHE_OPERATION and GL_CACHE_CLEANUP events 
        // by using the traceModule as a listener.
        HRESULT hr = pModuleInfo->SetGlobalNotifications
            (traceModule, GL_CACHE_OPERATION | GL_CACHE_CLEANUP);
                        
        // If the SetGlobalNotifications method 
        // fails, return the HRESULT.
        if (FAILED(hr))
        {
            return hr;
        }

        // Set the priority to PRIORITY_ALIAS_FIRST, 
        // which will populate the data as much as possible.
        hr = pModuleInfo->SetPriorityForGlobalNotification(
            GL_CACHE_OPERATION, PRIORITY_ALIAS_FIRST);

        // Return the HRESULT from the call to 
        // the SetGlobalNotifications method.
        return hr;
    }
    // The OnGlobalCacheOperation method is called 
    // when GL_CACHE_OPERATION operations occur.
    // pProvider: the current ICacheProvider pointer.
    // return: GL_NOTIFICATION_CONTINUE.
    virtual GLOBAL_NOTIFICATION_STATUS OnGlobalCacheOperation
    (
        IN ICacheProvider* pProvider
    )
    {
        // The OnGlobalCacheOperation must return if the 
        // pProvider parameter is NULL because this pointer 
        // is needed for data to write to the event log.
        if (NULL == pProvider)
        {
            return GL_NOTIFICATION_CONTINUE;
        }

        // The following code uses COM smart pointers. Wrap 
        // the code in one try/catch statement for _com_error
        // exceptions. Note: it is not necessary to call 
        // CoInitialize and CoUninitialize on this thread 
        // because IIS does this automatically.
        try
        {
            // Create an XML document in memory.
            MSXML2::IXMLDOMDocument3Ptr doc(__uuidof(MSXML2::DOMDocument60));

            // Create a cacheProvider root element and 
            // append this root element to the XML document.
            MSXML2::IXMLDOMElementPtr cacheProviderElement =
                doc->createElement(L"cacheProvider");
            doc->appendChild(cacheProviderElement);

            // Get the IHttpTraceContext pointer 
            // from the ICacheProvider pointer.
            IHttpTraceContext* traceContext = 
                pProvider->GetTraceContext();

            // Create an element for the IHttpTraceContext
            // pointer and add that element to the 
            // cacheProviderElement.
            MSXML2::IXMLDOMElementPtr traceElement =
                CreateElement(traceContext, doc);
            cacheProviderElement->appendChild(traceElement);

            // Write the XML using the writer.            
            m_eventWriter.ReportInfo(doc);    
        }
        // Catch any _com_error that occurs while you are 
        // writing to the XML document in memory.
        catch (_com_error& ce)
        {            
            // Get the description for the error.
            wstring description = ce.Description();
            // Write the error to the event writer.
            m_eventWriter.ReportError(description);
        }

        // Return GL_NOTIFICATION_CONTINUE so that 
        // other listeners will receive the event.
        return GL_NOTIFICATION_CONTINUE;
    }

    // The OnGlobalCacheCleanup method is called when 
    // GL_CACHE_CLEANUP events occur.
    // return: GL_NOTIFICATION_CONTINUE.
    virtual GLOBAL_NOTIFICATION_STATUS OnGlobalCacheCleanup(VOID)
    {
        // Return GL_NOTIFICATION_CONTINUE so that 
        // other listeners will receive this event.
        return GL_NOTIFICATION_CONTINUE;
    }

    // PRE: none.
    // POST: the Terminate method calls delete on this,
    // which releases the memory for the current 
    // CGlobalCacheModule pointer on the heap.
    virtual VOID Terminate(VOID)
    {
        delete this;
    }
protected:
    // Creates the constructor for 
    // the CGlobalCacheModule class.
    CGlobalCacheModule() : m_eventWriter(L"IISADMIN")
    {

    }

    // The AddAttribute creates a new attribute using 
    // the doc value, sets the new attribute's name and 
    // text, adds the new attribute to the element value 
    // and, finally, returns the attribute.
    // PRE: neither the element nor the doc 
    // parameters are NULL.
    // name: the name of the attribute.
    // text: the text of the attribute.
    // element: the element to add the new attribute to.
    // doc: the XML document for creating a new attribute.
    // return: the new IXMLDOMAttributePtr 
    // that is added to the element.
    // throws: a _com_error exception.
    static MSXML2::IXMLDOMAttributePtr AddAttribute
    (
        const wstring& name,
        const wstring& text,
        MSXML2::IXMLDOMElementPtr element,
        MSXML2::IXMLDOMDocument3Ptr doc
    ) throw (_com_error)
    {
        // Create an attribute with the name.
        MSXML2::IXMLDOMAttributePtr attribute = 
            doc->createAttribute(name.c_str());
        // Set the text of the attribute to the text value.
        attribute->text = text.c_str();
        // Add the attribute to the passed element.
        element->setAttributeNode(attribute);
        // Return the new attribute to the caller.
        return attribute;
    }

    // The CreateElement method converts an HTTP_TRACE_CONFIGURATION
    // pointer and its data into an XML element.
    // PRE: the doc parameter must not be NULL.    
    // traceConfiguration: the HTTP_TRACE_CONFIGURATION 
    // pointer to convert to an XML element.
    // hr: the HRESULT returned from retrieving 
    // the HTTP_TRACE_CONFIGURATION data.
    // doc: the MSXML2::IXMLDOMDocument3Ptr to 
    // use for creating a new element.    
    // return: a new MSXML2::IXMLDOMElementPtr.
    // throws: a _com_error exception.
    static MSXML2::IXMLDOMElementPtr CreateElement
    (
        HTTP_TRACE_CONFIGURATION* traceConfiguration,
        HRESULT hr,
        MSXML2::IXMLDOMDocument3Ptr doc        
    ) throw (_com_error)
    {
        // Create a default cacheSpecificData element to return.
        MSXML2::IXMLDOMElementPtr traceConfigurationElement =
            doc->createElement(L"traceConfiguration");

        // If the HTTP_TRACE_CONFIGURATION data is 
        // NULL or the HRESULT from getting the data 
        // is not S_OK, return the new empty element.
        if ((NULL == traceConfiguration) ||
            (FAILED(hr)))
        {
            return traceConfigurationElement;
        }

        // Get provider GUID information from
        // the HTTP_TRACE_CONFIGURATION pointer.
        LPCGUID providerGuidLPCGUID =
            traceConfiguration->pProviderGuid;
        // Convert the GUID to a wstring.
        wstring providerGuid =
            CConvert::ToString(providerGuidLPCGUID);
        
        // Add a providerGuid attribute to
        // the traceConfigurationElement.
        AddAttribute(L"providerGuid", providerGuid,                      
                     traceConfigurationElement, doc);

        // Get dwAreas information from
        // the HTTP_TRACE_CONFIGURATION pointer.
        DWORD areasDWORD =
            traceConfiguration->dwAreas;
        // Convert the DWORD to a wstring.
        wstring areas = CConvert::ToString(areasDWORD);

        // Add an areas attribute to
        // the traceConfigurationElement.
        AddAttribute(L"areas", areas,                      
                     traceConfigurationElement, doc);    

        // Get verbosity information from
        // the HTTP_TRACE_CONFIGURATION pointer.
        DWORD verbosityDWORD =
            traceConfiguration->dwVerbosity;
        // Convert the DWORD to a wstring.
        wstring verbosity =
            CConvert::ToString(verbosityDWORD);

        // Add a verbosity attribute to
        // the traceConfigurationElement.
        AddAttribute(L"verbosity", verbosity,
                     traceConfigurationElement, doc);

        // Get enabled information from the
        // HTTP_TRACE_CONFIGURATION pointer.
        BOOL providerEnabledBOOL =
            traceConfiguration->fProviderEnabled;
        // Convert the Boolean to a wstring.
        wstring providerEnabled = 
            CConvert::ToString(providerEnabledBOOL);
        
        // Add an attribute to the traceConfigurationElement 
        // for provider-enabled information.
        AddAttribute(L"providerEnabled", providerEnabled,                     
                     traceConfigurationElement, doc);

        // Return the traceConfigurationElement to the caller.
        return traceConfigurationElement;
    }

    // The CreateElement method converts an IHttpTraceContext
    // pointer and its descendant data into an XML element.
    // PRE: the doc parameter must not be NULL.    
    // traceContext: the IHttpTraceContext 
    // pointer to convert to an XML element.
    // doc: the MSXML2::IXMLDOMDocument3Ptr to 
    // use for creating a new element.    
    // return: a new MSXML2::IXMLDOMElementPtr.
    // throws: a _com_error exception.
    static MSXML2::IXMLDOMElementPtr CreateElement
    (
        IHttpTraceContext* traceContext,
        MSXML2::IXMLDOMDocument3Ptr doc
    ) throw (_com_error)
    {
        // Create a default cacheSpecificData element.
        MSXML2::IXMLDOMElementPtr traceContextElement =
            doc->createElement(L"traceContext");

        // Return the traceContext element if the IHttpTraceContext 
        // pointer data is NULL.
        if (NULL == traceContext)
        {
            return traceContextElement;
        }
        
        // Get trace configuration information 
        // from the IHttpTraceContext pointer.
        HTTP_TRACE_CONFIGURATION traceConfig;
        traceConfig.dwAreas = 0;
        traceConfig.dwVerbosity = 0;
        traceConfig.fProviderEnabled = FALSE;
        traceConfig.pProviderGuid = NULL;        
        HRESULT hr = 
            traceContext->GetTraceConfiguration(&traceConfig);

        // Create a trace configuration element
        // and append it to the traceContextElement.
        MSXML2::IXMLDOMElementPtr traceConfigElement =
            CreateElement(&traceConfig, hr, doc);
        traceContextElement->appendChild(traceConfigElement);

        // Get the activity identifier from
        // the IHttpTraceContext pointer.
        LPCGUID activityIdLPCGUID =
            traceContext->GetTraceActivityId();
        // Convert the activity identifier 
        // to a wstring.
        wstring activityId = 
            CConvert::ToString(activityIdLPCGUID);
        
        // Add an attribute to the traceContextElement 
        // for the activity identifier.
        AddAttribute(L"activityId", activityId,                     
                     traceContextElement, doc);
        
        // Return the traceContextElement.
        return traceContextElement;
    }
private:
    // Specify the event writer.
    CEventWriter m_eventWriter;
};

// The RegisterModule method is the 
// main entry point for the DLL.
// dwServerVersion: the current server version.
// pModuleInfo: the current 
// IHttpModuleRegistrationInfo pointer.
// pGlobalInfo: the current IHttpServer pointer.
// return: the value returned by calling the
// CGlobalCacheModule::RegisterGlobalModule
// method.
HRESULT
__stdcall
RegisterModule(
    DWORD dwServerVersion,
    IHttpModuleRegistrationInfo* pModuleInfo,
    IHttpServer* pGlobalInfo
)
{        
    // Call the static method for initialization.
    return CGlobalCacheModule::RegisterGlobalModule            
        (dwServerVersion, 
         pModuleInfo, 
         pGlobalInfo);             
}

For more information on how to create and deploy a native DLL module, see Walkthrough: Creating a Request-Level HTTP Module By Using Native Code.

The above code writes a new event to the application log of the Event Viewer, where the Data box contains XML similar to the following.

<cacheProvider>  
    <traceContext   
        activityId=  
           "{00000000-0000-0000-2400-0080000000FB}">  
        <traceConfiguration   
            providerGuid="NULL"   
            areas="0"   
            verbosity="0"   
            providerEnabled="false"/>  
    </traceContext>  
</cacheProvider>  

You can optionally compile the code by using the __stdcall (/Gz) calling convention instead of explicitly declaring the calling convention for each function.

Requirements

See Also

ICacheProvider Interface