Variant Streaming Code

.

Overview

This code provides two global functions, WriteVariantToStream and ReadVariantFromStream, that enable you to read and write a variant to a stream. In addition, there are two other global functions, ReadVariantFromBlob and WriteVariantToBlob, for reading and writing a variant to a BLOB.

Highlights

Here are some of the main advantages of these functions:
  • Uses any given IStream to stream the Variant into and out of.
  • Data is streamed in efficient binary form.
  • Stream is versioned for backwards compatibility.
  • Supports arbitrary size and arbitrary dimension safe-arrays.
  • Object streaming is supported if the object in variant supports IPersistStream[Init].
  • All code is in one header file (VariantStream.h) and only two routines are exposed: WriteVariantToStream and ReadVariantFromStream.
  • Comes with supporting test code that tests the header file -- in case code is modified
  • Does not use C++ exception handling.  Test project has EH flag turned..
  • Doesn't use the CRT.
  • Does not use any Direct-To-COM (VC++'s comdef.h, such as _variant_t, _bstr_t, _com_ptr, _com_error)
  • Works in both Unicode and ANSI

Downloads

Download source - 37 Kb


Comments

  • There may be a way to do this using VARIANT_UserMarshal, VARIANT_UserUnmarshal

    Posted by kasajian on 01/14/2010 05:14pm

    It may be possible to do this using these functions: VARIANT_UserMarshal VARIANT_UserUnmarshal

    Reply
  • The hope page for this code

    Posted by kasajian on 08/23/2007 12:31pm

    http://kasajian.com/VariantStream.html

    Reply
  • Excellent!

    Posted by Legacy on 01/09/2003 12:00am

    Originally posted by: Greg Holt

    Very well thought out code. Very clean and easy to understand. I don't understand why Microsoft doesn't provide this functionality.

    Only enhancement that I would like to see (and will probably end up writing it myself) is the ability to use BLOB data instead of an IStream. I know that you can use StreamToTaskMemory and BlobToStream but I don't want the overhead of having to always create a Stream everytime I want to write/read a variant.

    Reply
Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Live Event Date: May 18, 2015 @ 1:00 p.m. ET / 10:00 a.m. PT While the idea of using facial and or gesture recognitions to create a modern, intuitive game seems attractive, some developers may want to leverage Unity 3D as a way to accelerate their development. There are many different ways in which Intel and Unity Technologies have been working together to helps speed the develop of games with the Intel® RealSense™ SDK (Software Developer Kit), so come hear from a panel of experts on what we've done …

  • There has been growing buzz about DevOps. DevOps is a methodology that unites the often separate functions of software development (Dev) and production and operations (Ops) into a single, integrated, and continuous process. DevOps is about breaking down the barriers between Dev and Ops. It leverages people, processes, and technology to stimulate collaboration and innovation across the entire software development and release process. Dev and Ops should always be part of an integrated process, but that's not …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date