Re: #import mapi.h
On Friday, 23 March 2018 at 01:12:58 UTC, Mike Parker wrote:
On Thursday, 22 March 2018 at 21:45:40 UTC, Martin Tschierschke
wrote:
On Thursday, 22 March 2018 at 17:42:46 UTC, Paul Backus wrote:
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin
Tschierschke wrote:
Is there an step by step introduction how to convert a C
header of an external lib into the right extern(C){} block?
In addition to what others have said, I found the following
article on the D Wiki useful:
https://wiki.dlang.org/D_binding_for_C
Thank you, this one is very good!
If you have Learning D, chapter 9 is all about interface D with
C.
I will look at it! I have seen your hint already, you have
mentioned it in the beginning of your blogpost. The discussion in
an other thread [1] about direct integration of an C/C++
preprocessor into the D complier(s) is very interesting, I think
this will push the adoption of the language, because you just can
start immediately to use D as a replacement for C or C++. It is
very fascinating to see how D is evolving all the time. Now I
hope that with the survey and more donations the D Foundation get
the ability to push this even more.
[1]
https://forum.dlang.org/post/hvanbsyrydsxpizlt...@forum.dlang.org
Re: #import mapi.h
On Thursday, 22 March 2018 at 21:45:40 UTC, Martin Tschierschke
wrote:
On Thursday, 22 March 2018 at 17:42:46 UTC, Paul Backus wrote:
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin
Tschierschke wrote:
Is there an step by step introduction how to convert a C
header of an external lib into the right extern(C){} block?
In addition to what others have said, I found the following
article on the D Wiki useful:
https://wiki.dlang.org/D_binding_for_C
Thank you, this one is very good!
If you have Learning D, chapter 9 is all about interface D with C.
Re: #import mapi.h
On Thursday, 22 March 2018 at 17:42:46 UTC, Paul Backus wrote:
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin
Tschierschke wrote:
Is there an step by step introduction how to convert a C
header of an external lib into the right extern(C){} block?
In addition to what others have said, I found the following
article on the D Wiki useful:
https://wiki.dlang.org/D_binding_for_C
Thank you, this one is very good!
Re: #import mapi.h
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin Tschierschke
wrote:
Is there an step by step introduction how to convert a C header
of an external lib into the right extern(C){} block?
In addition to what others have said, I found the following
article on the D Wiki useful:
https://wiki.dlang.org/D_binding_for_C
Re: #import mapi.h
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin Tschierschke
wrote:
Is there an step by step introduction how to convert a C header
of an external lib into the right extern(C){} block?
In short, they should be binary compatible: where is a pointer on
C side, should be a pointer on D side, same for integer sizes,
data layout an calling conventions.
Re: #import mapi.h
On Thursday, 22 March 2018 at 12:53:23 UTC, Martin Tschierschke
wrote:
On Wednesday, 21 March 2018 at 17:12:07 UTC, Timoses wrote:
[...]
I got it, my first mini test with C bindings!
Important missing at first: (stderr)
import core.stdc.stdio : stderr, FILE;
and use of toStringz inside: mapi_query(dbh, toStringz(q) )
After installing monetdb and starting the server with:
https://www.monetdb.org/Documentation/UserGuide/Tutorial
My minimal version of the example compiled with
dmd app.d -I /usr/local/lib/libmapi.so
(My dub.json is still incomplete so the linking failed.)
Here is the code: (only the minimum of mapi.h is icluded!)
```
std.stdio;
import std.string;
/* interfacing winth monetdb #include mapi.h */
/* minimum to run code of example at:
https://www.monetdb.org/Documentation/Manuals/SQLreference/Programming/MAPI */
import core.stdc.stdio : stderr,FILE;
import core.stdc.stdlib;
struct MapiStruct;
alias Mapi = MapiStruct*;
struct MapiStatement;
alias MapiHdl = MapiStatement*;
enum MOK = 0 ;
alias MapiMsg = int;
extern(System){
Mapi mapi_connect(const char* host, int port, const char*
username, const char* password, const char* lang, const char*
dbname);
MapiHdl mapi_query(Mapi mid, const char *cmd);
int mapi_fetch_row(MapiHdl hdl);
char *mapi_fetch_field(MapiHdl hdl, int fnr);
MapiMsg mapi_error(Mapi mid);
MapiMsg mapi_explain(Mapi mid, FILE* fd);
MapiMsg mapi_destroy(Mapi mid);
MapiMsg mapi_close_handle(MapiHdl hdl);
MapiMsg mapi_explain_result(MapiHdl hdl, FILE* fd);
MapiMsg mapi_next_result(MapiHdl hdl);
MapiMsg mapi_explain_query(MapiHdl hdl, FILE* fd);
char *mapi_result_error(MapiHdl hdl);
}
void die(Mapi dbh, MapiHdl hdl) {
if (hdl != null) {
mapi_explain_query(hdl, stderr);
do {
if (mapi_result_error(hdl) != null)
mapi_explain_result(hdl, stderr);
} while (mapi_next_result(hdl) == 1);
mapi_close_handle(hdl);
mapi_destroy(dbh);
} else if (dbh != null) {
mapi_explain(dbh, stderr);
mapi_destroy(dbh);
} else {
fprintf(stderr, "command failed\n");
}
exit(-1);
}
MapiHdl query(Mapi dbh, string q) {
MapiHdl ret = null;
if ((ret = mapi_query(dbh, toStringz(q) )) == null ||
mapi_error(dbh) != MOK)
die(dbh, ret);
return(ret);
}
void update(Mapi dbh, string q) {
MapiHdl ret = query(dbh, q);
if (mapi_close_handle(ret) != MOK)
die(dbh, ret);
}
void main()
{
auto dbh = mapi_connect("localhost", 5, "monetdb",
"monetdb", "sql", "voc");
writeln("DB-connect");
update(dbh, "CREATE TABLE emp (name VARCHAR(20), age INT)");
writeln("create");
update(dbh, "INSERT INTO emp VALUES ('John', 23)");
update(dbh, "INSERT INTO emp VALUES ('Mary', 22)");
auto hdl = query(dbh, "SELECT * FROM emp");
while (mapi_fetch_row(hdl)) {
auto name = mapi_fetch_field(hdl, 0);
auto age = mapi_fetch_field(hdl, 1);
printf("%s is %s\n", name, age);
}
}
```
Will try to make a complete binding available later...
Re: #import mapi.h
On Wednesday, 21 March 2018 at 17:12:07 UTC, Timoses wrote:
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin
Tschierschke wrote:
Is there an step by step introduction how to convert a C
header of an external lib into the right extern(C){} block?
A blog post or tutorial, or chapter in a D book? (I have those
from Packt Publishing)
While googling I found this:
https://dlang.org/blog/2017/12/05/interfacing-d-with-c-getting-started/
Haven't read it yet, but might give you some more insight.
For automatic conversion I stumbled across Dstep which I so far
like a lot:
https://github.com/jacob-carlborg/dstep
Thank you! I will have a look at both, an Mike Parker is pointing
to his book, too,
so now together with the post from "nkm1" I should be able to
make it!
@ketmar, I learned C but the counter of years from that time was
stored in a nibble and so I got an overflow...error :-)
Re: #import mapi.h
On Wednesday, 21 March 2018 at 18:42:43 UTC, nkm1 wrote: On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin Tschierschke wrote: [...] The easiest thing to do is to write a wrapper in C. The wrapper will include all necessary headers and provide some easy to use functions that you can call from D. Of course, you'll need to use a C compiler to compile it. Anyway, this header looks very straightforwar, no particular tricks with the preprocessor. It should be something like this (untested, obviously): [...] Thank you! Especially this was a missing link: struct MapiStruct; alias Mapi = MapiStruct*;
Re: #import mapi.h
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin Tschierschke
wrote:
Is there an step by step introduction how to convert a C header
of an external lib into the right extern(C){} block?
A blog post or tutorial, or chapter in a D book? (I have those
from Packt Publishing)
(Especially I am trying to get this used with D:
Montetdb C-API
https://www.monetdb.org/Documentation/Manuals/SQLreference/Programming/MAPI
With:
https://github.com/snaga/monetdb/blob/master/clients/mapilib/mapi.h)
The page: https://dlang.org/spec/interfaceToC.html is known,
but not detailed enough for me.
The easiest thing to do is to write a wrapper in C. The wrapper
will include all necessary headers and provide some easy to use
functions that you can call from D. Of course, you'll need to use
a C compiler to compile it.
Anyway, this header looks very straightforwar, no particular
tricks with the preprocessor. It should be something like this
(untested, obviously):
import core.stdc.stdio : FILE;
enum
{
MAPI_AUTO = 0, /* automatic type detection */
MAPI_TINY = 1,
MAPI_UTINY = 2,
MAPI_SHORT = 3,
MAPI_USHORT= 4,
MAPI_INT = 5,
MAPI_UINT = 6,
MAPI_LONG = 7,
MAPI_ULONG = 8,
MAPI_LONGLONG = 9,
MAPI_ULONGLONG = 10,
MAPI_CHAR = 11,
MAPI_VARCHAR = 12,
MAPI_FLOAT = 13,
MAPI_DOUBLE= 14,
MAPI_DATE = 15,
MAPI_TIME = 16,
MAPI_DATETIME = 17,
MAPI_NUMERIC = 18,
}
enum int PLACEHOLDER = '?';
enum
{
MAPI_SEEK_SET = 0,
MAPI_SEEK_CUR = 1,
MAPI_SEEK_END = 2,
}
enum
{
MAPI_TRACE = 1,
MAPI_TRACE_LANG = 2,
}
alias MapiMsg = int;
enum
{
MOK = 0,
MERROR = -1,
MTIMEOUT= -2,
MMORE = -3,
MSERVER = -4,
}
enum
{
LANG_MAL= 0,
LANG_SQL= 2,
LANG_JAQL = 3,
}
/* prompts for MAPI protocol */
enum int PROMPTBEG = '\001'; /* start prompt bracket */
/* prompt: ready for new query */
const(char)* PROMPT1 = "\001\001\n".ptr;
/* prompt: more data needed */
const(char)* PROMTP2 = "\001\002\n".ptr;
/*
* The table field information is extracted from the table headers
* obtained from the server. This list may be extended in the
future.
* The type of both the 'param' and 'binding'
* variables refer to their underlying C-type. They are used for
* automatic type coercion between back-end and application.
*/
struct MapiStruct;
alias Mapi = MapiStruct*;
/* this definition is a straight copy from
sql/include/sql_query.h */
enum
{
Q_PARSE = 0,
Q_TABLE = 1,
Q_UPDATE= 2,
Q_SCHEMA= 3,
Q_TRANS = 4,
Q_PREPARE = 5,
Q_BLOCK = 6,
}
struct MapiStatement;
alias MapiHdl = MapiStatement*;
alias mapi_uint64 = ulong;
alias mapi_int64 = long;
/* three structures used for communicating date/time information
*/
/* these structs are deliberately compatible with the ODBC
versions
SQL_DATE_STRUCT, SQL_TIME_STRUCT, and SQL_TIMESTAMP_STRUCT */
/* used by MAPI_DATE */
struct MapiDate
{
short year;
ushort month;
ushort day;
}
/* used by MAPI_TIME */
struct MapiTime
{
ushort hour;
ushort minute;
ushort second;
}
/* used by MAPI_DATETIME */
struct MapiDateTime
{
short year;
ushort month;
ushort day;
ushort hour;
ushort minute;
ushort second;
uint fraction; /* in 1000 millionths of a second (10e-9) */
}
/* connection-oriented functions */
extern (C)
{
Mapi mapi_mapi(const char *host,
int port,
const char *username,
const char *password,
const char *lang,
const char *dbname);
// and so on...
}
Re: #import mapi.h
On Wednesday, 21 March 2018 at 16:22:45 UTC, Martin Tschierschke
wrote:
Is there an step by step introduction how to convert a C header
of an external lib into the right extern(C){} block?
A blog post or tutorial, or chapter in a D book? (I have those
from Packt Publishing)
While googling I found this:
https://dlang.org/blog/2017/12/05/interfacing-d-with-c-getting-started/
Haven't read it yet, but might give you some more insight.
For automatic conversion I stumbled across Dstep which I so far
like a lot:
https://github.com/jacob-carlborg/dstep
Re: #import mapi.h
Martin Tschierschke wrote: or tutorial ok, tutorial: 1. learn C. 2. learn D. 3. DO IT! ;-)
#import mapi.h
Is there an step by step introduction how to convert a C header
of an external lib into the right extern(C){} block?
A blog post or tutorial, or chapter in a D book? (I have those
from Packt Publishing)
(Especially I am trying to get this used with D:
Montetdb C-API
https://www.monetdb.org/Documentation/Manuals/SQLreference/Programming/MAPI
With:
https://github.com/snaga/monetdb/blob/master/clients/mapilib/mapi.h)
The page: https://dlang.org/spec/interfaceToC.html is known, but
not detailed enough for me.
