VMS Help DCE_RPC, Application Routines, wchar_t_local_size  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 NAME

   wchar_t_local_size - Calculates the necessary buffer size for code
                        set conversion from a network code set to a
                        local code set

   Used by client and server applications.

 SYNOPSIS

   #include <dce/rpc.h>

   void wchar_t_local_size( rpc_binding_handle_t binding,
                            unsigned32 network_code_set_value,
                            unsigned32 network_buffer_size,
                            idl_cs_convert_t *conversion_type,
                            unsigned32 *local_buffer_size,
                            error_status_t *status );

 PARAMETERS

   Input

   binding
       Specifies the target binding handle from which to obtain buffer
       size evaluation information. When called from the client stub,
       this value is the binding handle of a compatible server returned
       by the rpc_ns_binding_import_next() or rpc_ns_binding_select()
       routine.  When called from the server stub, this value is a
       pointer to binding information that the client stub passed in
       the RPC call.

   network_code_set_value
       The registered hexadecimal integer value that represents the code
       set used to transmit character data over the network.  In general,
       the "network" code set is the code set that the client
       application's code sets evaluation routine has determined to be
       compatible for this client and server.  When the caller is the
       client stub, this value is the receiving tag.  When the caller
       is the server stub, this value is the sending tag.

   network_buffer_size
       The size, in units of idl_byte, of the buffer that is allocated
       for the international character data, For a conformant or
       conformant varying array, this value is the network value of the
       size_is variable for the array; that is, the value is the size of
       the unmarshalled string if no conversion is done.

   Output

   conversion_type
       A pointer to the enumerated type defined in dce/idlbase.h that
       indicates whether data conversion is necessary and whether or not
       the existing buffer is sufficient for storing the results of the
       conversion. Since idl_byte to wchar_t conversion always takes
       place, and idl_byte and wchar_t require a different number of
       bytes, the conversion type is always idl_cs_new_buffer_convert,
       which means that the converted data must be written to a new
       buffer.

   local_buffer_size
       A pointer to the buffer size that needs to be allocated to contain
       the converted data, in units of wchar_t.  This value is to be used
       as the local value of the size_is variable for the array, and is
       non-NULL only if a conformant or conformant varying array is to be
       unmarshalled.  A value of NULL in this parameter indicates that a
       fixed or varying array is to be unmarshalled.

   status
       Returns the status code from this routine.  This status code
       indicates whether the routine completed successfully or, if not,
       why not.

       The possible status codes and their meanings are as follows:

       rpc_s_ok   Success.

       rpc_s_ss_incompatible_codesets
                  The specified code set does not match the code set
                  specified in the sending tag in the binding handle.
                  If this error occurs in the server stub, an exception
                  is raised to the client application.

   When invoked from the server stub, this routine calls the routines
   dce_cs_loc_to_rgy() and rpc_rgy_get_max_bytes().  If either of these
   routines returns an error, the wchar_t_local_size() routine raises an
   exception to the client application.

 DESCRIPTION

   The wchar_t_local_size() routine belongs to a set of DCE RPC routines
   for use by client and server applications that are transferring
   international character data in a heterogeneous character set and
   code sets environment.

   The wchar_t_local_size() routine is one of the DCE RPC buffer sizing
   routines that RPC stubs use before they marshall or unmarshall data
   to determine whether or not the buffers allocated for code set
   conversion need to be enlarged to hold the converted data.  The buffer
   sizing routines determine the type of conversion required and
   calculate the size of the necessary buffer (if a conformant or
   conformant varying array is to be marshalled).  The RPC stub then
   allocates a buffer of that size before it calls one of the code set
   conversion routines.

   Client and server stubs call the wchar_t_*_size routines when the
   wchar_t type has been specified as the argument to the cs_char
   attribute in the attribute configuration file for the application.
   Applications do not call wchar_t_local_size() routine directly.
   Client and server stubs call the routine before they unmarshall any
   data.  The stubs pass the routine a binding handle and a code set
   value that identifies the code set that was used to transfer
   international character data over the network. The stubs also
   specify the network storage size of the data, in units of idl_byte.

   When called from a client stub, the wchar_t_local_size() routine
   determines the value of conversion_type from conversion method and
   tag information set up in the binding handle by a code sets
   evaluation routine or a tag-setting routine.  Since idl_byte to
   wchar_t require different numbers of bytes to encode one character
   unit, the routine always sets the value to idl_cs_new_buffer_convert,
   which means that the converted data must be written to a new buffer.
   The routine sets the conversion_type parameter to this value and, if
   a conformant or conformant varying array is to be unmarshalled,
   calculates a new buffer size by dividing the value of
   network_buffer_size by the number of bytes required to encode one
   wchar_t unit.  The routine returns the new buffer size in the
   local_buffer_size parameter. The size is specified in units of
   wchar_t, which is the local representation used for international
   character data.

   In cases where the binding handle does not contain the results of
   character and code sets evaluation, or where it is being called from
   the server stub, the wchar_t_local_size() routine determines the
   value of conversion_type itself using the local code set value and
   the code set value passed in the network_code_set_value parameter
   and returns the appropriate conversion_type value.  If a conformant
   or conformant varying array is to be unmarshalled, the routine
   calculates the size of this new buffer (by multiplying the value of
   network_buffer_size by dividing the value of network_buffer_size by
   the number of bytes required to encode one wchar_t unit, and returns
   the results, in units of wchar_t, in local_buffer_size.

   Permissions Required

   No permissions are required.

 RETURN VALUES

   No value is returned.

 RELATED INFORMATION

   Functions: byte_net_size
              byte_local_size
              wchar_t_net_size