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RetrieveUrlCacheEntryFile function

Locks the cache entry file associated with the specified URL.

Syntax


BOOLAPI RetrieveUrlCacheEntryFile(
  _In_     LPCTSTR lpszUrlName,
  _Out_    LPINTERNET_CACHE_ENTRY_INFO lpCacheEntryInfo,
  _Inout_  LPDWORD lpcbCacheEntryInfo,
  _In_     DWORD dwReserved
);

Parameters

lpszUrlName [in]

Pointer to a string that contains the URL of the resource associated with the cache entry. This must be a unique name. The name string should not contain any escape characters.

lpCacheEntryInfo [out]

Pointer to a cache entry information buffer. If the buffer is not sufficient, this function returns ERROR_INSUFFICIENT_BUFFER and sets lpdwCacheEntryInfoBufferSize to the number of bytes required.

lpcbCacheEntryInfo [in, out]

Pointer to an unsigned long integer variable that specifies the size of the lpCacheEntryInfo buffer, in bytes. When the function returns, the variable contains the size, in bytes, of the actual buffer used or the number of bytes required to retrieve the cache entry file. The caller should check the return value in this parameter. If the return size is less than or equal to the size passed in, all the relevant data has been returned.

dwReserved [in]

This parameter is reserved and must be 0.

Return value

Returns TRUE if successful, or FALSE otherwise. To get extended error information, call GetLastError. Possible error values include:

Return codeDescription
ERROR_FILE_NOT_FOUND

The cache entry specified by the source name is not found in the cache storage.

ERROR_INSUFFICIENT_BUFFER

The size of the lpCacheEntryInfo buffer as specified by lpdwCacheEntryInfoBufferSize is not sufficient to contain all the information. The value returned in lpdwCacheEntryInfoBufferSize indicates the buffer size necessary to get all the information.

 

Remarks

RetrieveUrlCacheEntryFile does not do any URL parsing, so a URL containing an anchor (#) will not be found in the cache, even if the resource is cached. For example, if the URL http://adatum.com/example.htm#sample was passed, the function would return ERROR_FILE_NOT_FOUND even if http://adatum.com/example.htm is in the cache.

The file is locked for the caller when it is retrieved; the caller should unlock the file after the caller is finished with the file. The cache manager automatically unlocks the files after a certain interval. While the file is locked, the cache manager will not remove the file from the cache. It is important to note that this function may or may not perform efficiently, depending on the internal implementation of the cache. For instance, if the URL data is stored in a packed file that contains data for other URLs, the cache will make a copy of the data to a file in a temporary directory maintained by the cache. The cache will eventually delete the copy. It is recommended that this function be used only in situations where a file name is needed to launch an application. RetrieveUrlCacheEntryStream and associated stream functions should be used in most cases.

Like all other aspects of the WinINet API, this function cannot be safely called from within DllMain or the constructors and destructors of global objects.

Note  WinINet does not support server implementations. In addition, it should not be used from a service. For server implementations or services use Microsoft Windows HTTP Services (WinHTTP).

Requirements

Minimum supported client

Windows 2000 Professional

Minimum supported server

Windows 2000 Server

Header

Wininet.h

Library

Wininet.lib

DLL

Wininet.dll

Unicode and ANSI names

RetrieveUrlCacheEntryFileW (Unicode) and RetrieveUrlCacheEntryFileA (ANSI)

See also

Caching
WinINet Functions

 

 

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