[postmodern-devel] Bulk Copying

[Andy Chambers]

Hi All,

I'm trying to add support for bulk copying to postmodern.  Does anyone  
have any ideas on
how it should be done.  Here's my suggestion...

1) Add message primitives (we seem to already have copy-done-message)

(define-message copy-data-message #\d (data)
   (string data))

(define-message copy-fail-message #\f (reason)
   (string reason))


2) Add a "bulk-copier" class with slots for
      db      ; the connection we're using
      table   ; the table we're copying from/to
      from/to ; whether we're copying from or to a table
      header  ; whether to include a header row in output/input
         ;; plus slots for the CSV options
      delimiter
      null-str
      quote-str
      escape-str

3) A function open-copier creates an instance of the above class and sends  
the
    corresponding copy statement to Postgres before returning the object.

4) A function copy-row takes a row (i.e. a simple list of Lisp values),  
and writes
    them to the stream attached to the copier.

5) A function copy-done lets Postgres know we're finished and commits the  
change
    to the database.

Anyone got any hints for debugging this low-level stuff?  I seem to be  
able to
open a copier (and send the copy statement to pg) but when I send the
complete-command message in copy-done, my code is hanging.

-- 
Andy Chambers