ICacheProvider：：GetCacheRecord 方法
返回缓存提供程序的缓存记录。
语法
virtual IHttpCacheSpecificData* GetCacheRecord(
VOID
) const = 0;
参数
此方法不采用参数。
返回值
指向 IHttpCacheSpecificData 接口的指针。
备注
注册GL_CACHE_OPERATION事件的 CGlobalModule 派生类接收 ICacheProvider 指针作为 CGlobalModule：：OnGlobalCacheOperationvirtual 方法的参数。 可以通过对指针调用 GetCacheRecord 方法ICacheProvider来检索IHttpCacheSpecificData指针。
实现者须知
ICacheProvider 实现者将指针声明 private``IHttpCacheSpecificData 为成员数据。 调用这些实现器的构造函数时，会将此成员数据分配给指针 IHttpCacheSpecificData 。 在调用 SetCacheRecord method之前，调用方负责首先在指针上IHttpCacheSpecificData调用 IHttpCacheSpecificData：：ReferenceCacheData 方法;SetCacheRecord然后，实现者将private变量分配给此IHttpCacheSpecificData指针。
下表是一对一接口映射的示例，这些映射必须从 GetCacheKey 和 GetCacheRecord 接口的同一实现程序 ICacheProvider 返回的方法。
| GetCacheKey 接口 | GetCacheRecord 接口 |
|---|---|
| IFileKey | IHttpFileInfo |
| IHttpTokenKey | IHttpTokenEntry |
| IHttpCacheKey | IHttpCacheSpecificData |
对调用者的说明
ICacheProvider 实现者获取指针的 IHttpCacheSpecificData 所有权。 在调用 SetCacheRecord之前，首先对指针调用 IHttpCacheSpecificData::ReferenceCacheData ，以便此指针具有一个所有者。 的 GetCacheRecord 调用方不获取返回 IHttpCacheSpecificData 的指针的所有权。
在某些情况下，从 GetCacheRecord 返回的IHttpCacheSpecificData指针可能会向下转换到更具体的接口，以访问扩展行为。 GetCacheKey调用 方法以检索IHttpCacheKey指针，然后调用 IHttpCacheKey：：GetCacheName 方法来检索缓存的名称。 下表列出了从 GetCacheName 返回的示例值，以及当前指针随后可以安全向下转换的相应接口 IHttpCacheSpecificData （假设发生其他正确的下置过程）。 有关 常量值，请参阅 IIS 缓存常 量。
| GetCacheName 值 | 接口 |
|---|---|
| 文件 | IHttpFileInfo |
| 令 牌 | IHttpTokenEntry |
注意
在执行任何向下转换操作之前，请始终验证强制转换是否正确，以确保正确的程序行为。
注意
在执行向下转换操作时，尽可能考虑使用 dynamic_cast 运算符。
示例
下面的代码示例演示如何创建一个全局模块，该模块侦GL_CACHE_OPERATION听和GL_CACHE_CLEANUP事件，IHttpCacheSpecificData然后将信息写入事件查看器。
注意
IIS 7 在事件查看器中生成大量事件。 若要避免生产环境中的日志溢出错误，通常应避免将缓存信息写入事件日志。 出于演示目的，此代码示例仅在调试模式下将条目写入事件查看器。
#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 IHttpCacheSpecificData pointer
// from the ICacheProvider element.
IHttpCacheSpecificData* cacheSpecificData =
pProvider->GetCacheRecord();
// Create an element for the IHttpCacheSpecificData
// pointer and add that element to the
// cacheProviderElement.
MSXML2::IXMLDOMElementPtr recordElement =
CreateElement(cacheSpecificData, doc);
cacheProviderElement->appendChild(recordElement);
// 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 IHttpStoredContext
// pointer and its descendant data to an XML element.
// PRE: the doc parameter must not be NULL.
// storedContext: the IHttpStoredContext
// pointer to convert to an XML element.
// doc: the XML document for creating elements.
// return: a new MSXML2::IXMLDOMElementPtr representing the
// data in the storedContext parameter and its descendants.
// throws: a _com_error exception.
static MSXML2::IXMLDOMElementPtr CreateElement
(
IHttpStoredContext* storedContext,
MSXML2::IXMLDOMDocument3Ptr doc
) throw (_com_error)
{
// Create a new element to return.
MSXML2::IXMLDOMElementPtr storedContextElement =
doc->createElement(L"storedContext");
// If the storedContext pointer is NULL,
// return the storedContextElement.
if (NULL == storedContext)
{
return storedContextElement;
}
// Return the storedContextElement to the caller.
return storedContextElement;
}
// The CreateElement method converts an IHttpModuleContextContainer
// and its descendant data into an XML element.
// PRE: the doc parameter must not be NULL.
// contextContainer: the IHttpModuleContextContainer
// pointer to convert to an XML element.
// doc: the XML document used for creating elements.
// return: a new MSXML2::IXMLDOMElementPtr representing the
// data in the contextContainer parameter and its descendants.
// throws: a _com_error exception.
static MSXML2::IXMLDOMElementPtr CreateElement
(
IHttpModuleContextContainer* contextContainer,
MSXML2::IXMLDOMDocument3Ptr doc
) throw (_com_error)
{
// Create a new element to return.
MSXML2::IXMLDOMElementPtr contextContainerElement =
doc->createElement(L"contextContainer");
// If the contextContainer pointer is NULL, return the
// contextContainerElement.
if (NULL == contextContainer)
{
return contextContainerElement;
}
// Get the IHttpStoredContext pointer from
// the IHttpModuleContextContainer pointer.
IHttpStoredContext* storedContext =
contextContainer->GetModuleContext(NULL);
// Add a new element from the IHttpStoredContext
// pointer to the contextContainerElement.
MSXML2::IXMLDOMElementPtr storedContextElement =
CreateElement(storedContext, doc);
contextContainerElement->appendChild(storedContextElement);
// Return the contextContainerElement.
return contextContainerElement;
}
// The CreateElement method converts an IHttpTokenEntry
// pointer and its descendant data into an XML element.
// PRE: the doc parameter must not be NULL.
// tokenEntry: the IHttpTokenEntry
// pointer to convert to an XML element.
// doc: the XML document used for creating elements.
// return: a new MSXML2::IXMLDOMElementPtr representing the
// data in the tokenEntry parameter and its descendants.
// throws: a _com_error exception.
static MSXML2::IXMLDOMElementPtr CreateElement
(
IHttpTokenEntry* tokenEntry,
MSXML2::IXMLDOMDocument3Ptr doc
) throw (_com_error)
{
// Create a new element to return.
MSXML2::IXMLDOMElementPtr tokenEntryElement =
doc->createElement(L"tokenEntry");
// If the tokenEntry parameter is NULL,
// return the empty tokenEntryElement.
if (NULL == tokenEntry)
{
return tokenEntryElement;
}
// Get the impersonation token from
// the IHttpTokenEntry pointer.
HANDLE impersonationTokenHANDLE =
tokenEntry->GetImpersonationToken();
// Convert the token to a wstring.
wstring impersonationToken =
CConvert::ToString(impersonationTokenHANDLE);
// Add an impersonationToken attribute
// to the tokenEntryElement.
AddAttribute(L"impersonationToken", impersonationToken,
tokenEntryElement, doc);
// Get the primary token from the
// IHttpTokenEntry pointer.
HANDLE primaryTokenHANDLE =
tokenEntry->GetPrimaryToken();
// Convert the primary token to
// a wstring.
wstring primaryToken =
CConvert::ToString(primaryTokenHANDLE);
// Add a primaryToken attribute to
// the tokenEntryElement.
AddAttribute(L"primaryToken", primaryToken,
tokenEntryElement, doc);
// Get the SID from the
// IHttpTokenEntry pointer.
PSID sidPSID = tokenEntry->GetSid();
// Convert the SID to a wstring.
wstring sid = CConvert::ToString(sidPSID);
// Add an attribute to the tokenEntryElement
// for the SID.
AddAttribute(L"sid", sid,
tokenEntryElement, doc);
// Return the tokenEntryElement to the caller.
return tokenEntryElement;
}
// The CreateElement method converts an IHttpFileInfo
// pointer and its descendant data into an XML element.
// PRE: the doc parameter must not be NULL.
// fileInfo: the IHttpFileInfo pointer
// to convert to an XML element.
// return: a new MSXML2::IXMLDOMElementPtr representing
// the data in the fileInfo parameter and its descendants.
// throws: a _com_error exception.
static MSXML2::IXMLDOMElementPtr CreateElement
(
IHttpFileInfo* fileInfo,
MSXML2::IXMLDOMDocument3Ptr doc
) throw (_com_error)
{
// Create a new element to return.
MSXML2::IXMLDOMElementPtr fileInfoElement =
doc->createElement(L"fileInfo");
// If the fileInfo pointer is NULL,
// return the empty fileInfoElement.
if (NULL == fileInfo)
{
return fileInfoElement;
}
// Get file-changed information from
// the IHttpFileInfo pointer.
BOOL changedBOOL =
fileInfo->CheckIfFileHasChanged(NULL);
// Covert the Boolean to a wstring.
wstring changed = CConvert::ToString(changedBOOL);
// Add a changed attribute to
// the fileInfoElement.
AddAttribute(L"changed", changed,
fileInfoElement, doc);
// Get attribute information from
// the IHttpFileInfo pointer.
DWORD attributesDWORD =
fileInfo->GetAttributes();
// Convert the attributes to a wstring.
wstring attributes =
CConvert::ToString(attributesDWORD);
// Add an attributes attribute to
// the fileInfoElement.
AddAttribute(L"attributes", attributes,
fileInfoElement, doc);
// Get eTag information from the
// IHttpFileInfo pointer.
PCSTR eTagPCSTR = fileInfo->GetETag();
// Convert the eTag to a wstring.
wstring eTag = CConvert::ToString(eTagPCSTR);
// Add an eTag attribute to
// the fileInfoElement.
AddAttribute(L"eTag", eTag,
fileInfoElement, doc);
// Get the file buffer as a raw BYTE
// pointer from the IHttpFileInfo pointer.
const BYTE* fileBuffer = fileInfo->GetFileBuffer();
// Convert the buffer to a string.
wstring buffer =
CConvert::ToString(NULL != fileBuffer);
// Add a buffer attribute to
// the fileInfoElement.
AddAttribute(L"buffer", buffer,
fileInfoElement, doc);
// Get the file HANDLE from the
// IHttpFileInfo pointer.
HANDLE handleHANDLE =
fileInfo->GetFileHandle();
// Convert the HANDLE to a wstring.
wstring handle = CConvert::ToString(handleHANDLE);
// Add an attribute to the fileInfoElement
// for file handle information.
AddAttribute(L"handle", handle,
fileInfoElement, doc);
// Get the path from the
// IHttpFileInfo pointer.
wstring path = fileInfo->GetFilePath();
// Add a path attribute to
// the fileInfoElement.
AddAttribute(L"path", path,
fileInfoElement, doc);
// Declare a DWORD for seconds to live.
DWORD secondsToLiveDWORD = 0;
// Get cache allowed information from the
// IHttpFileInfo pointer.
BOOL cacheAllowedBOOL =
fileInfo->GetHttpCacheAllowed(&secondsToLiveDWORD);
// Convert the Boolean to a wstring.
wstring cacheAllowed =
CConvert::ToString(cacheAllowedBOOL);
// Convert the seconds-to-live
// to a wstring.
wstring secondsToLive =
CConvert::ToString(secondsToLiveDWORD);
// Add an attribute to the fileInfoElement
// indicating if caching is allowed.
AddAttribute(L"cacheAllowed", cacheAllowed,
fileInfoElement, doc);
// Add an attribute to the fileInfoElement
// for the number of seconds to live.
AddAttribute(L"secondsToLive", secondsToLive,
fileInfoElement, doc);
// Get last modified information from
// the IHttpFileInfo pointer.
PCSTR lastModifiedPCSTR =
fileInfo->GetLastModifiedString();
// Convert the PCSTR string to
// a wstring.
wstring lastModifiedString =
CConvert::ToString(lastModifiedPCSTR);
// Add an attribute to the fileInfoElement
// for last-modified information.
AddAttribute(L"lastModifiedString", lastModifiedString,
fileInfoElement, doc);
// Get the last modified time from
// the IHttpFileInfo pointer.
FILETIME lastModifiedTimeFILETIME;
fileInfo->GetLastModifiedTime(&lastModifiedTimeFILETIME);
// Convert the last modified time
// to a wstring.
wstring lastModifiedTime =
CConvert::ToString(&lastModifiedTime);
// Add a lastModifiedTime attribute to
// the fileInfoElement.
AddAttribute(L"lastModifiedTime", lastModifiedTime,
fileInfoElement, doc);
// Get the IHttpModuleContextContainer pointer
// from the IHttpFileInfo pointer.
IHttpModuleContextContainer* contextContainer =
fileInfo->GetModuleContextContainer();
// Add a container element to the
// fileInfoElement element.
MSXML2::IXMLDOMElementPtr contextContainerElement =
CreateElement(contextContainer, doc);
fileInfoElement->appendChild(contextContainerElement);
// Get the file size from the
// IHttpFileInfo pointer.
ULARGE_INTEGER fileSizeInt;
fileInfo->GetSize(&fileSizeInt);
// Convert the ULARGE_INTEGER to
// a wstring.
wstring size = CConvert::ToString(&fileSizeInt);
// Add a size attribute to
// the fileInfoElement.
AddAttribute(L"size", size,
fileInfoElement, doc);
// Get the VR path from the
// IHttpFileInfo pointer.
wstring vrPath = fileInfo->GetVrPath();
// Add a vrPath attribute to
// the fileInfoElement.
AddAttribute(L"vrPath", vrPath,
fileInfoElement, doc);
// Get the VR token from the
// IHttpFileInfo pointer.
HANDLE vrTokenHANDLE =
fileInfo->GetVrToken();
// Convert the HANDLE to
// a wstring.
wstring vrToken = CConvert::ToString(vrTokenHANDLE);
// A a vrToken attribute to
// the fileInfoElement.
AddAttribute(L"vrToken", vrToken,
fileInfoElement, doc);
// Return the fileInfoElement.
return fileInfoElement;
}
// The CreateElement method converts an IHttpCacheSpecificData
// and its descendant data into an XML element.
// PRE: the doc parameter must not be NULL.
// cacheSpecificData: the IHttpCacheSpecificData
// pointer to convert to an XML element.
// doc: the XML document to use for creating elements.
// return: a new MSXML2::IXMLDOMElementPtr.
// throws: a _com_error exception.
static MSXML2::IXMLDOMElementPtr CreateElement
(
IHttpCacheSpecificData* cacheSpecificData,
MSXML2::IXMLDOMDocument3Ptr doc
) throw (_com_error)
{
// Create a default cacheSpecificData element.
MSXML2::IXMLDOMElementPtr cacheSpecificDataElement =
doc->createElement(L"cacheSpecificData");
// If the cacheSpecificData is NULL,
// return the empty cacheSpecificDataElement.
if (NULL == cacheSpecificData)
{
return cacheSpecificDataElement;
}
// Get the IHttpCacheKey pointer from the
// IHttpCacheSpecificData pointer.
IHttpCacheKey* cacheKey =
cacheSpecificData->GetCacheKey();
// If the cacheKey is non-NULL, get its name.
// This may allow downcasting to a more specific
// IHttpCacheSpecificData pointer type.
if (NULL != cacheKey)
{
// Get the cache name from the cacheKey.
wstring cacheKeyName = cacheKey->GetCacheName();
// If the cacheKeyName is FILE_CACHE_NAME, the
// IHttpCacheSpecificData pointer can be downcast
// to an IHttpFileInfo pointer.
if (FILE_CACHE_NAME == cacheKeyName)
{
// Attempt to cast the IHttpCacheSpecificData
// pointer to an IHttpFileInfo pointer.
IHttpFileInfo* fileInfo =
dynamic_cast<IHttpFileInfo*>(cacheSpecificData);
// Reset the cacheSpecificDataElement
// to the new element.
cacheSpecificDataElement =
CreateElement(fileInfo, doc);
}
// If the cacheKeyName is TOKEN_CACHE_NAME, the
// IHttpCacheSpecificData pointer can be
// downcast to an IHttpTokenEntry pointer.
if (TOKEN_CACHE_NAME == cacheKeyName)
{
// Attempt to cast the IHttpCacheSpecificData
// pointer to an IHttpTokenEntry pointer.
IHttpTokenEntry* tokenEntry =
dynamic_cast<IHttpTokenEntry*>(cacheSpecificData);
// Reset the cacheSpecificDataElement
// to the new element.
cacheSpecificDataElement =
CreateElement(tokenEntry, doc);
}
}
// Get flushed information from the
// IHttpCacheSpecificData pointer.
BOOL flushedBOOL =
cacheSpecificData->GetFlushed();
// Convert the Boolean to
// a wstring.
wstring flushed = CConvert::ToString(flushedBOOL);
// Add a flushed attribute to the
// cacheSpecificDataElement.
AddAttribute(L"flushed", flushed,
cacheSpecificDataElement, doc);
// Return the new cacheSpecificDataElement to the caller.
return cacheSpecificDataElement;
}
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);
}
有关如何创建和部署本机 DLL 模块的详细信息，请参阅 演练：使用本机代码创建Request-Level HTTP 模块。
上述代码将新事件写入事件查看器的应用程序日志，其中“数据”框包含如下所示的 XML。
<cacheProvider>
<fileInfo />
</cacheProvider>
<cacheProvider>
<tokenEntry />
</cacheProvider>
可以选择使用 __stdcall (/Gz) 调用约定编译代码，而不是为每个函数显式声明调用约定。
要求
| 类型 | 说明 |
|---|---|
| 客户端 | - Windows Vista 上的 IIS 7.0 - Windows 7 上的 IIS 7.5 - Windows 8 上的 IIS 8.0 - Windows 10 上的 IIS 10.0 |
| 服务器 | - Windows Server 2008 上的 IIS 7.0 - Windows Server 2008 R2 上的 IIS 7.5 - Windows Server 2012 上的 IIS 8.0 - Windows Server 2012 R2 上的 IIS 8.5 - Windows Server 2016 上的 IIS 10.0 |
| 产品 | - IIS 7.0、IIS 7.5、IIS 8.0、IIS 8.5、IIS 10.0 - IIS Express 7.5、IIS Express 8.0、IIS Express 10.0 |
| Header | Httpserv.h |