dtSearch Text Retrieval Engine Programmer's Reference
dtsConvertPathRequest Structure

Used by dtssConvertPath2 to convert among virtual, local, and UNC paths

File: dtsearch.h

struct dtsConvertPathRequest { dtsErrorInfo * errorHandler; long flags; char * dest; long maxLen; const char * path; long siteId; const char * registryKey; };

Internet Information Server stores its mapping between virtual and local paths in the Metabase. Reading this information from the Metabase is time-consuming and requires access rights that may not be available to a process running in the web server context. Therefore, the dtSearch Engine caches this information in the registry, under the key HKEY_LOCAL_MACHINESoftwaredtSearch Corp.dtSearchVirtual Roots. By default, the conversion will use the cached table values. Call ConvertPath with the dtsCpRefreshMappings + dtsCpStoreInRegistry flags to update the cached information. (Running dtWebSetup.exe, the dtSearch Web Setup program, will also update this information.) 

If path conversion returns a blank string, it means that either (1) the folder passed in does not have a virtual directory associated with it, or (2) the registry tables have not been refreshed since the virtual directory was created.