subject:"HELP mysql_server_init embedded in a DLL\?"

Re: HELP mysql_server_init embedded in a DLL?

2003-03-02 Thread Gelu Gogancea

Hi,
- Original Message -
From: Derick Smith [EMAIL PROTECTED]
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Sent: Friday, February 28, 2003 9:09 PM
Subject: Re: HELP mysql_server_init embedded in a DLL?

 Attempts at creating an embedded mySQL DLL for VB:

 I can successfully use the mysql_init() function from libmysql.lib to
create
 a DLL for VB. However, when I use this function (in a DLL or lib)linked
 against the libmysqld.lib or mysqlserver.lib it crashes the VB application
 but not the C application.

 I tried hard coding the arguments and servergroups for mysql_server_init
(I
 also used memset to initialize the strings to 0), I get the same result.

 The lib I create will always work with a C program, but the DLL will not
 work with VB.
You must take care with CALLING CONVENTIONS(__stdcall).This is be one reason
for crash.

 Does anyone have any more suggestions on how to use the embedded library
in
 a Visual C DLL to link with VB?
You can not access directly the mysql api function from VB.Are ,at least,two
big problems :the VB type STRING which is UNICODE ; passing the data
structure (like MYSQL which contain node lists) from VB to C or reverse.In
my opinion you should make functions which will be interface between MYSQL C
API and VB.Also you should make your own function to convert char to unicode
and reverse.It's better if you don't use MultiByteToWideChar()...you will
get a lot of unpleasure surprises.
Of course you can do some improvisation (like in mysql_init or to convert a
STRING into ARRAY of BYTE) but is not a solution because VB imediatly will
give you some error like OUT OF MEMORY.

Regards,

Gelu
_
G.NET SOFTWARE COMPANY

Permanent e-mail address : [EMAIL PROTECTED]
  [EMAIL PROTECTED]

 Thanks
 Eric

 p.s: Email received from another individual (Thanks!!):

 Put the libMySql.dll in the wint\system32 directory (or in the directory
 where
 your executable is!)

 In vb, I use this one

 the declares:

 Public Declare Function mysql_init Lib libmySQL   (ByVal lMYSQL As Long)
 As
 Long
 Public Declare Function mysql_real_connect Lib libmySQL _
 (ByVal lMYSQL As Long, _
 ByVal sHostName As String, _
 ByVal sUserName As String, _
 ByVal sPassword As String, _
 ByVal sDbName As String, _
 ByVal lPortNum As Long, _
 ByVal sSocketName As String, _
 ByVal lFlags As Long) As Long

 Public Function OpenConnection(ByVal sHostName As String, _
 ByVal sUserName As String, _
 ByVal sPassword As String, _
 ByVal sDbName As String, _
 Optional ByVal lPortNum As Long = 3306, _
 Optional ByVal lFlags As MYSQL_FLAG) As
 MYSQL_CONNECTION_STATE

 mlMYSQL = mysql_init(mlMYSQL)
 If mlMYSQL = 0 Then
 no connection handler
 Else

 'connect to server
 If mysql_real_connect(mlMYSQL, msHostname, msUsername, msPassword,
 msDbName, mlPortNum, , mlFlags) = 0 Then
   ' oops
 Else
 'connection established ... state is now open
 End If
 End If

 'setup the return value
 End Function

 I myselve created an dll (in vb) which encapsulates all the stuff to
connect
 to
 the database, use recordsets,  (as close as possible to the ADO object
 model: so with connection, recordset - objects,
 bookmarks, fields, ...)

 Hope this helps.

 From: Gelu Gogancea [EMAIL PROTECTED]
 To: Derick Smith
 [EMAIL PROTECTED],[EMAIL PROTECTED],[EMAIL PROTECTED]
 Subject: Re: HELP mysql_server_init embedded in a DLL?
 Date: Fri, 28 Feb 2003 14:40:31 +0200

 Hi,
 - Original Message -
 From: Derick Smith [EMAIL PROTECTED]
 To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
 Sent: Thursday, February 27, 2003 10:33 PM
 Subject: Re: HELP mysql_server_init embedded in a DLL?

   I am posting this again, in hope that I will get a response.

   I tried doing the following (see VB code below. I got this code from
 another
   site):

   I get the same error message as if I was calling the DLL I created in
C
   which calls mysql_server_init.

   Is it impossible to call this function from VB or embedded in another
 DLL
   from VB?
   Can I only use the embedded mysql library in C or C++?

   Thanks
   Eric

   Public Declare Function mysql_server_init Lib
   C:\mysql40\source\lib_release\libmysqld.dll _
   (ByVal argc As Long, _
   ByVal argv As Byte, _
   ByVal groups As Byte) As Long

   Private Sub cmdmysq_server_init_Click()
   Dim argv(0) As Byte, groups(0) As Byte
   Dim i As Long
   argv(0) = Asc(0)
   groups(0) = Asc(0)
   i = mysql_server_init(0, argv, groups)
   End Sub
 In my opinion,this will never work because argv and groups are pointed to
 array which have a pointer char

Re: HELP mysql_server_init embedded in a DLL?

2003-02-28 Thread Gelu Gogancea

Hi,
- Original Message -
From: Derick Smith [EMAIL PROTECTED]
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Sent: Thursday, February 27, 2003 10:33 PM
Subject: Re: HELP mysql_server_init embedded in a DLL?

 I am posting this again, in hope that I will get a response.

 I tried doing the following (see VB code below. I got this code from
another
 site):

 I get the same error message as if I was calling the DLL I created in C
 which calls mysql_server_init.

 Is it impossible to call this function from VB or embedded in another DLL
 from VB?
 Can I only use the embedded mysql library in C or C++?

 Thanks
 Eric

 Public Declare Function mysql_server_init Lib
 C:\mysql40\source\lib_release\libmysqld.dll _
 (ByVal argc As Long, _
 ByVal argv As Byte, _
 ByVal groups As Byte) As Long

 Private Sub cmdmysq_server_init_Click()
 Dim argv(0) As Byte, groups(0) As Byte
 Dim i As Long
 argv(0) = Asc(0)
 groups(0) = Asc(0)
 i = mysql_server_init(0, argv, groups)
 End Sub
In my opinion,this will never work because argv and groups are pointed to
array which have a pointer char*(*);
But anyhow...if you wish to try again this formula, must declare argv and
groups ByRef because VB is responsable for the stack and the variable must
be initialized  before using like argument in function.Since argv and groups
are byte is a non-sense to use ASC().
I'm very pessimistic that will be work.

 From: Derick Smith [EMAIL PROTECTED]
 To: [EMAIL PROTECTED], [EMAIL PROTECTED]
 Subject: mysql_server_init embedded in a DLL?
 Date: Wed, 26 Feb 2003 14:34:28 +

 Hi!

 I am trying to create a DLL that will hide embedded mySQL functions for
use
 with VB. I am using mysqlserver.lib. I am able to compile and execute the
 following code. This has to be done in C because VB is too slow :-(

 If mysql_server_init function is run in the DLL from Visual Basic. I get
 the following error message: ..referenced memory at 0x00. The
 memory could not be read.

 Without the mysql_server_init function it will run correctly. It will
also
 run correctly when this is compiled as a .lib file linked to a C program.

 Is it possible to embed mysql_server_init in a DLL? (So the DLL can be
used
 in VB)

 Thanks in advance for any responses.

 Thanks
 Eric

 header1.h

 #define GPAPI __stdcall

 header2.h

 typedef unsigned long DBS;
 #define NULLDBS  (DBS)0

 api.c

 GPAPI DBS dbNewSet (char * basedir, char * datadir, char * dbname)
 {
  return NewSet(basedir,datadir,dbname);
 }

 newset.c

 extern DBS NewSet(char * basedir, char * datadir, char * dbname)
 {
  DBSET* pSet = CreateSet();
  char *args[3];
  char strArgs[3][1024];
I guess some problems can be elimanted if you initialize the variables which
are declared or if you allocate some memory.
Anyhow you can use '\0' - termination string to be sure that you don't have
*other garbage* after your string.This *garbage*  can influence the lenght
of the string.Bad thing.

  int iRtn;
  int argc = 3;

  strcpy(strArgs[0],this_program);

  sprintf(strArgs[1],--basedir=%s,basedir);
  sprintf(strArgs[2],--datadir=%s,datadir);
  args[0]= strArgs[0];
  args[1]= strArgs[1];
  args[2]= strArgs[2];

 /* If I comment out this line of code,
 the DLL will run correctly.
 If mysql_server_init function is run in the DLL. I get the following
 error message: ..referenced memory at 0x00. The
...this means that one of your variables is NULL.This error occur because
you don't *catch* the right pointer.By using equal sign you pass the pointer
to lvalue and not the value.At the address of pointer you can find the
value.

 memory could not be read */
  iRtn = mysql_server_init(3, args, server_groups);

  if (pSet ==0 ) return NULLDBS;
  memset(pSet, 0, sizeof(DBSET)); /* Zero the structure.*/
 pSet-size  = sizeof(DBSET);/* Assign structure size. */
 pSet-magic = DBS_MAGIC;  /* Assign magic number.   */

  return (DBS)(void*)pSet;
 }

If you have a little patience (maybe a week or two...i try to find some
available time for this) a new version of GMySQL(An interface between MYSQL
C API function and VB or other development platform for Windows) will be
released.This new version, will contain the implementation of the new
replication functions and also will be able to work with libmysqld.

Regards,

Gelu
_
G.NET SOFTWARE COMPANY

Permanent e-mail address : [EMAIL PROTECTED]
  [EMAIL PROTECTED]

 _
 The new MSN 8: smart spam protection and 2 months FREE*
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 To unsubscribe, e-mail

Re: HELP mysql_server_init embedded in a DLL?

2003-02-28 Thread Derick Smith

Attempts at creating an embedded mySQL DLL for VB:

I can successfully use the mysql_init() function from libmysql.lib to create 
a DLL for VB. However, when I use this function (in a DLL or lib)linked 
against the libmysqld.lib or mysqlserver.lib it crashes the VB application 
but not the C application.

I tried hard coding the arguments and servergroups for mysql_server_init (I 
also used memset to initialize the strings to 0), I get the same result.

The lib I create will always work with a C program, but the DLL will not 
work with VB.

Does anyone have any more suggestions on how to use the embedded library in 
a Visual C DLL to link with VB?

Thanks
Eric
p.s: Email received from another individual (Thanks!!):

Put the libMySql.dll in the wint\system32 directory (or in the directory 
where
your executable is!)

In vb, I use this one

the declares:

Public Declare Function mysql_init Lib libmySQL   (ByVal lMYSQL As Long) 
As
Long
Public Declare Function mysql_real_connect Lib libmySQL _
   (ByVal lMYSQL As Long, _
   ByVal sHostName As String, _
   ByVal sUserName As String, _
   ByVal sPassword As String, _
   ByVal sDbName As String, _
   ByVal lPortNum As Long, _
   ByVal sSocketName As String, _
   ByVal lFlags As Long) As Long

Public Function OpenConnection(ByVal sHostName As String, _
   ByVal sUserName As String, _
   ByVal sPassword As String, _
   ByVal sDbName As String, _
   Optional ByVal lPortNum As Long = 3306, _
   Optional ByVal lFlags As MYSQL_FLAG) As
MYSQL_CONNECTION_STATE
  
   mlMYSQL = mysql_init(mlMYSQL)
   If mlMYSQL = 0 Then
   no connection handler
   Else
   'connect to server
   If mysql_real_connect(mlMYSQL, msHostname, msUsername, msPassword,
msDbName, mlPortNum, , mlFlags) = 0 Then
 ' oops
   Else
   'connection established ... state is now open
   End If
   End If
   'setup the return value
End Function
I myselve created an dll (in vb) which encapsulates all the stuff to connect 
to
the database, use recordsets,  (as close as possible to the ADO object
model: so with connection, recordset - objects,
bookmarks, fields, ...)

Hope this helps.







From: Gelu Gogancea [EMAIL PROTECTED]
To: Derick Smith 
[EMAIL PROTECTED],[EMAIL PROTECTED],[EMAIL PROTECTED]
Subject: Re: HELP mysql_server_init embedded in a DLL?
Date: Fri, 28 Feb 2003 14:40:31 +0200

Hi,
- Original Message -
From: Derick Smith [EMAIL PROTECTED]
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Sent: Thursday, February 27, 2003 10:33 PM
Subject: Re: HELP mysql_server_init embedded in a DLL?
 I am posting this again, in hope that I will get a response.

 I tried doing the following (see VB code below. I got this code from
another
 site):

 I get the same error message as if I was calling the DLL I created in C
 which calls mysql_server_init.

 Is it impossible to call this function from VB or embedded in another 
DLL
 from VB?
 Can I only use the embedded mysql library in C or C++?

 Thanks
 Eric

 Public Declare Function mysql_server_init Lib
 C:\mysql40\source\lib_release\libmysqld.dll _
 (ByVal argc As Long, _
 ByVal argv As Byte, _
 ByVal groups As Byte) As Long

 Private Sub cmdmysq_server_init_Click()
 Dim argv(0) As Byte, groups(0) As Byte
 Dim i As Long
 argv(0) = Asc(0)
 groups(0) = Asc(0)
 i = mysql_server_init(0, argv, groups)
 End Sub
In my opinion,this will never work because argv and groups are pointed to
array which have a pointer char*(*);
But anyhow...if you wish to try again this formula, must declare argv and
groups ByRef because VB is responsable for the stack and the variable must
be initialized  before using like argument in function.Since argv and 
groups
are byte is a non-sense to use ASC().
I'm very pessimistic that will be work.





 From: Derick Smith [EMAIL PROTECTED]
 To: [EMAIL PROTECTED], [EMAIL PROTECTED]
 Subject: mysql_server_init embedded in a DLL?
 Date: Wed, 26 Feb 2003 14:34:28 +
 
 Hi!
 
 I am trying to create a DLL that will hide embedded mySQL functions for
use
 with VB. I am using mysqlserver.lib. I am able to compile and execute 
the
 following code. This has to be done in C because VB is too slow :-(
 
 If mysql_server_init function is run in the DLL from Visual Basic. I 
get
 the following error message: ..referenced memory at 0x00. The
 memory could not be read.
 
 Without the mysql_server_init function it will run correctly. It will
also
 run correctly when this is compiled as a .lib file linked to a C 
program.
 
 Is it possible to embed mysql_server_init in a DLL? (So the DLL can be
used
 in VB)
 
 Thanks in advance for any responses.
 
 Thanks
 Eric
 
 
 header1.h
 
 #define GPAPI __stdcall
 
 header2.h
 
 typedef unsigned long DBS;
 #define NULLDBS  (DBS)0
 
 api.c
 
 GPAPI DBS dbNewSet (char * basedir, char

Re: HELP mysql_server_init embedded in a DLL?

2003-02-27 Thread Derick Smith

I am posting this again, in hope that I will get a response.

I tried doing the following (see VB code below. I got this code from another 
site):

I get the same error message as if I was calling the DLL I created in C 
which calls mysql_server_init.

Is it impossible to call this function from VB or embedded in another DLL 
from VB?
Can I only use the embedded mysql library in C or C++?

Thanks
Eric
Public Declare Function mysql_server_init Lib 
C:\mysql40\source\lib_release\libmysqld.dll _
   (ByVal argc As Long, _
   ByVal argv As Byte, _
   ByVal groups As Byte) As Long

Private Sub cmdmysq_server_init_Click()
   Dim argv(0) As Byte, groups(0) As Byte
   Dim i As Long
   argv(0) = Asc(0)
   groups(0) = Asc(0)
   i = mysql_server_init(0, argv, groups)
End Sub



From: Derick Smith [EMAIL PROTECTED]
To: [EMAIL PROTECTED], [EMAIL PROTECTED]
Subject: mysql_server_init embedded in a DLL?
Date: Wed, 26 Feb 2003 14:34:28 +
Hi!

I am trying to create a DLL that will hide embedded mySQL functions for use 
with VB. I am using mysqlserver.lib. I am able to compile and execute the 
following code. This has to be done in C because VB is too slow :-(

If mysql_server_init function is run in the DLL from Visual Basic. I get 
the following error message: ..referenced memory at 0x00. The
memory could not be read.

Without the mysql_server_init function it will run correctly. It will also 
run correctly when this is compiled as a .lib file linked to a C program.

Is it possible to embed mysql_server_init in a DLL? (So the DLL can be used 
in VB)

Thanks in advance for any responses.

Thanks
Eric
header1.h

#define GPAPI __stdcall

header2.h

typedef unsigned long DBS;
#define NULLDBS  (DBS)0
api.c

GPAPI DBS dbNewSet (char * basedir, char * datadir, char * dbname)
{
return NewSet(basedir,datadir,dbname);
}
newset.c

extern DBS NewSet(char * basedir, char * datadir, char * dbname)
{
DBSET* pSet = CreateSet();
char*args[3];
char strArgs[3][1024];
int iRtn;
int argc = 3;
strcpy(strArgs[0],this_program);
sprintf(strArgs[1],--basedir=%s,basedir);
sprintf(strArgs[2],--datadir=%s,datadir);
args[0]= strArgs[0];
args[1]= strArgs[1];
args[2]= strArgs[2];
/* If I comment out this line of code,
the DLL will run correctly.
If mysql_server_init function is run in the DLL. I get the following
error message: ..referenced memory at 0x00. The
memory could not be read */
iRtn = mysql_server_init(3, args, server_groups);
if (pSet ==0 ) return NULLDBS;
memset(pSet, 0, sizeof(DBSET)); /* Zero the structure.*/
   pSet-size  = sizeof(DBSET);/* Assign structure size. */
   pSet-magic = DBS_MAGIC;  /* Assign magic number.   */
return (DBS)(void*)pSet;
}


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Re: HELP mysql_server_init embedded in a DLL?

Re: HELP mysql_server_init embedded in a DLL?

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Re: HELP mysql_server_init embedded in a DLL?

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