FreeTDS Development Group

[Brian Bruns <camber AT ais.org>]

The read.c thing is never referenced...I removed it.  The server directory
is a set of routines that allow an application to speak the server side of
the TDS protocol.  I'm using it in a connection pooling application I'm
writing now.  The idea is that the pool opens n connections to the
database and then you log into the pool and it sends back a login
acknowledgement (a bogus one actually) and all queries are assigned to a
currently idle connection.  Useful if you have a 10 license server and
want to put many more clients on it.

Brian

On Thu, 12 Oct 2000, Brandon M. Reynolds wrote:

> Brian Bruns wrote:
> > 
> > Actually, BUFSIZ is used only once in the code which is to do a malloc.
> > That needs to be cleaned up but it's not causing any problems.
> 
> Well, a little more than once, tds/login.c is probably OK, not sure
> about
> tds/read.c.  What's that stuff under the server directory get used for
> anyway?
> 
> [w3]freetds> grep -r BUFSIZ *
> samples/debug.c:unsigned char    buf[BUFSIZ];
> samples/debug.c:        while ((len = read(fd, buf, BUFSIZ)) > 0) {
> src/server/login.c:unsigned char buf[BUFSIZ];
> src/server/login.c:     tds = tds_alloc_socket(BUFSIZ);
> src/server/query.c:static unsigned char query[BUFSIZ];
> src/tds/login.c:        tds = tds_alloc_socket(BUFSIZ);
> src/tds/read.c:unsigned char buf[BUFSIZ];
> 
> > I think you've hit on the real problem here:
> > 
> > > +     if (tds->out_pos>=8192) {
> > 
> > It appears that TDS 7.0 does not allow multiple query packets!?
> > 
> > I'm guessing if you made the query larger than 8192 bytes this would again
> > fail.  I'll try to throw a permanent patch together (this one will break
> > TDS 4.2 and 5.0) if somebody is willing to test it.
> 
> Here's what I changed it to:
> -       if (tds->out_pos>=512) {
> +       if (!IS_TDS70(tds) && tds->out_pos>=512) {
> 
> I think SQL Server 7 can't handle queries longer than 8k, but I'm not
> sure.
> 
> While we're at it there's a couple of other things I'd like added...
> 1.  I changed the dbbuf to be dynamic.
> 
> 2.  In dbbind(), I changed one line to prevent dereferencing a NULL
> pointer.
> 
> 3.  I Changed dbsqlexec so that you don't have to do a fetch and make it
> fail in
>     order to not have your program crash!
> 
> I have tested these changes for some time and they work for me.  I have
> programs written in C and PHP.
> 
> Notice: these are not acurate diff's because I can't keep up with the
> CVS!
> 
> --- freetds/include/sybdb.h     Sat Oct  7 15:32:32 2000
> +++ freetds.good/include/sybdb.h        Fri Oct  6 11:28:21 2000
>     int             noautofree;
>     int             more_results; /* boolean.  Are we expecting results?
> */
>     BYTE           *user_data;   /* see dbsetuserdata() and
> dbgetuserdata() */
> -   unsigned char   dbbuf[8192]; /* XXX should be
> dynamic                   */
> +   unsigned char  *dbbuf; /* is dynamic!                   */
> +   int             dbbufsz;
>     int             empty_res_hack;
>     TDS_INT         text_size;
>     TDS_INT         text_sent;
> @@ -293,6 +296,7 @@
>  extern RETCODE    dbinit();
>  extern LOGINREC  *dblogin();
>  extern RETCODE    DBSETLPACKET(LOGINREC *login, short packet_size);
> +extern RETCODE    DBSETLCHARSET(LOGINREC *login, char *charset);
>  extern RETCODE    DBSETLPWD(LOGINREC *login, char *password);
>  extern RETCODE    DBSETLUSER(LOGINREC *login, char *username);
>  extern RETCODE    DBSETLHOST(LOGINREC *login, char *hostname);
> 
> --- freetds/src/dblib/dblib.c   Sun Oct  8 22:19:09 2000
> +++ freetds.good/src/dblib/dblib.c      Fri Oct  6 11:30:22 2000
> @@ -449,11 +448,13 @@
>         }
> 
>     dbproc->tds_socket = (void *) tds_connect(login->tds_login);
> -   dbproc->dbbuf[0]='\0'; /* initialize query buffer */
> +   dbproc->dbbuf = NULL;
> +   dbproc->dbbufsz = 0;
> 
>  RETCODE        dbcmd(DBPROCESS *dbproc, char *cmdstring)
>  {
> -       /* here is one of those large static buffers that should be
> malloced
> -       ** but in the interest of time i kludged :)   */
> -       strcat(dbproc->dbbuf,cmdstring);
> -       return SUCCEED;
> +  if(dbproc->dbbufsz == 0) {
> +    if((dbproc->dbbuf =
> +       (unsigned char *)malloc(strlen(cmdstring)+1)) == NULL) {
> +      return FAIL;
> +    }
> +    strcpy(dbproc->dbbuf,cmdstring);
> +    dbproc->dbbufsz = strlen(cmdstring) + 1;
> +  } else {
> +    int newsz;
> +    void *p;
> +
> +    newsz = strlen(cmdstring) + dbproc->dbbufsz;
> +    if((p=realloc(dbproc->dbbuf,newsz)) == NULL) {
> +      return FAIL;
> +    }

> +    dbproc->dbbuf = (unsigned char *)p;
> +    strcat(dbproc->dbbuf,cmdstring);
> +    dbproc->dbbufsz = newsz;
> +  }
> +
> +  return SUCCEED;
>  }
>  RETCODE dbsqlexec(DBPROCESS *dbproc)
>  {
> @@ -478,7 +507,9 @@
>     tds = (TDSSOCKET *) dbproc->tds_socket;
>     if (!tds || !tds->s) return FAIL;
> 
> -   if (tds->res_info && tds->res_info->more_results)
> +   if (tds->res_info && tds->res_info->more_results || tds->state ==
> TDS_PENDING)
>     /* if (dbproc->more_results &&
> tds_is_end_of_results(dbproc->tds_socket)) */
>     {
>        dbresults(dbproc);
> 
> @@ -833,8 +851,9 @@
>        tds     = (TDSSOCKET *) dbproc->tds_socket;
>        resinfo = tds->res_info;
>     }
> 
> -   okay = okay && ((column >= 1) && (column <= resinfo->num_cols));
> +   okay = okay && ((column >= 1) && (column <=
> (resinfo?resinfo->num_cols:0)));
> 
>     if (okay)
>     {
> @@ -1618,7 +1637,13 @@
> 
>  void dbfreebuf(DBPROCESS *dbproc)
>  {
> -   dbproc->dbbuf[0] = '\0';
> +  // bmr: 10-06-2000
> +  //   dbproc->dbbuf[0] = '\0';
> +  if(dbproc->dbbuf) {
> +    free(dbproc->dbbuf);
> +    dbproc->dbbuf = NULL;
> +  }
> +  dbproc->dbbufsz = 0;
>  } /* dbfreebuf()  */
> 
>  RETCODE dbclropt(DBPROCESS *dbproc,int option, char *param)
> @@ -1895,7 +1920,9 @@
>        }
>        if (! dbproc->noautofree)
>        {
> -         dbproc->dbbuf[0]='\0';
> +       dbfreebuf(dbproc);
>        }
>        result = SUCCEED;
>     }
> 
> -- 
> Brandon Reynolds                  Phone: (330) 644-3059
> Systems Engineer                    Fax: (330) 644-8110
> Commercial Timesharing Inc.      E-mail: bmr AT comtime.com
> 
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