Re: blk_textxfer

On Thu, Jan 19, 2012 at 09:50:16AM +0000, Zhongming cai wrote:
> 
> I need some help on how to implemente the blk_textfer in freetds ctlib. ... Can someone point me some directions on how I should accomplish this?

Hello David, 

We have no working function similar to blk_textfer() in any library.  The closest we have dbmoretext().  A patch to support it would be most welcome.  

You will need for reference: 

1.  Sybase's latest TDS documentation
2.  Sybase's OpenClient library

and

3.  tcpdump
4.  ribo
5.  patience


There are bulk copy tests in src/ctlib/unittests.  I would link them to Sybase's library and make sure they work as-is.  Then modify one to use blk_textfer().  Capture the stream with tdsdump and ribo, then explain it to yourself using the documentation.  Your job is to reproduce their stream.  

 
Your implementation would be called tds_blk_textfer() in src/tds/bulk.c.  blk_textfer() would be a wrapper in src/blk.c.  Ideally, tds_blk_textfer() could be used to implement the db-lib bcp_moretext() function, too.  

Feel free to post here if you have more questions.  

--jkl