You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
103 lines
3.4 KiB
103 lines
3.4 KiB
5 months ago
|
Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
|
||
|
|
|
||
|
|
How to create a new service
|
||
|
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
||
|
|
|
||
|
|
A "service" is a set of C functions in a structure that a
|
||
|
|
service dynamic linker uses when a dynamic plugin is loaded.
|
||
|
|
|
||
|
|
If you want to export C++ class you need to provide an
|
||
|
|
extern "C" function that will create a new instance of your class,
|
||
|
|
and put it in a service.
|
||
|
|
|
||
|
|
Data structures are not part of the service structure, but they are part
|
||
|
|
of the API you create and usually need to be declared in the same
|
||
|
|
service_*.h file.
|
||
|
|
|
||
|
|
To turn a set of functions (foo_func1, foo_func2)
|
||
|
|
into a service "foo" you need to
|
||
|
|
|
||
|
|
1. create a new file include/mysql/service_foo.h
|
||
|
|
|
||
|
|
2. the template is
|
||
|
|
==================================================================
|
||
|
|
#ifndef MYSQL_SERVICE_FOO_INCLUDED
|
||
|
|
/* standard GPL header */
|
||
|
|
|
||
|
|
/**
|
||
|
|
@file
|
||
|
|
*exhaustive* description of the interface you provide.
|
||
|
|
This file is the main user documentation of the new service
|
||
|
|
*/
|
||
|
|
#ifdef __cplusplus
|
||
|
|
extern "C" {
|
||
|
|
#endif
|
||
|
|
|
||
|
|
extern struct foo_service_st {
|
||
|
|
int (*foo_func1_type)(...); /* fix the prototype as appropriate */
|
||
|
|
void (*foo_func2_type)(...); /* fix the prototype as appropriate */
|
||
|
|
} *foo_service;
|
||
|
|
|
||
|
|
#ifdef MYSQL_DYNAMIC_PLUGIN
|
||
|
|
|
||
|
|
#define foo_func1(...) foo_service->foo_func1_type(...)
|
||
|
|
#define foo_func2(...) foo_service->foo_func2_type(...)
|
||
|
|
|
||
|
|
#else
|
||
|
|
|
||
|
|
int foo_func1_type(...); /* fix the prototype as appropriate */
|
||
|
|
void foo_func2_type(...); /* fix the prototype as appropriate */
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef __cplusplus
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#define MYSQL_SERVICE_FOO_INCLUDED
|
||
|
|
#endif
|
||
|
|
==================================================================
|
||
|
|
|
||
|
|
the service_foo.h file should be self-contained, if it needs system headers -
|
||
|
|
include them in it, e.g. if you use size_t - #include <stdlib.h>
|
||
|
|
|
||
|
|
it should also declare all the accompanying data structures, as necessary
|
||
|
|
(e.g. thd_alloc_service declares MYSQL_LEX_STRING).
|
||
|
|
|
||
|
|
3. add the new file to include/Makefile.am (pkginclude_HEADERS)
|
||
|
|
4. add the new file to include/mysql/services.h
|
||
|
|
5. increase the minor plugin ABI version in include/mysql/plugin.h
|
||
|
|
(MYSQL_PLUGIN_INTERFACE_VERSION = MYSQL_PLUGIN_INTERFACE_VERSION+1)
|
||
|
|
6. add the version of your service to include/service_versions.h:
|
||
|
|
==================================================================
|
||
|
|
#define VERSION_foo 0x0100
|
||
|
|
==================================================================
|
||
|
|
|
||
|
|
7. create a new file libservices/foo_service.c using the following template:
|
||
|
|
==================================================================
|
||
|
|
/* GPL header */
|
||
|
|
#include <service_versions.h>
|
||
|
|
SERVICE_VERSION *foo_service= (void*)VERSION_foo;
|
||
|
|
==================================================================
|
||
|
|
|
||
|
|
8. add the new file to libservices/CMakeLists.txt (MYSQLSERVICES_SOURCES)
|
||
|
|
9. add the new file to libservices/Makefile.am (libmysqlservices_a_SOURCES)
|
||
|
|
10. and finally, register your service for dynamic linking in
|
||
|
|
sql/sql_plugin_services.h
|
||
|
|
10.1 fill in the service structure:
|
||
|
|
==================================================================
|
||
|
|
static struct foo_service_st foo_handler = {
|
||
|
|
foo_func1,
|
||
|
|
foo_func2
|
||
|
|
}
|
||
|
|
==================================================================
|
||
|
|
|
||
|
|
10.2 and add it to the list of services
|
||
|
|
|
||
|
|
==================================================================
|
||
|
|
{ "foo_service", VERSION_foo, &foo_handler }
|
||
|
|
==================================================================
|
||
|
|
|
||
|
|
that's all.
|
||
|
|
|