diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:04:16 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 18:04:16 +0000 |
commit | a68fb2d8219f6bccc573009600e9f23e89226a5e (patch) | |
tree | d742d35d14ae816e99293d2b01face30e9f3a46b /libservices/HOWTO | |
parent | Initial commit. (diff) | |
download | mariadb-10.6-a68fb2d8219f6bccc573009600e9f23e89226a5e.tar.xz mariadb-10.6-a68fb2d8219f6bccc573009600e9f23e89226a5e.zip |
Adding upstream version 1:10.6.11.upstream/1%10.6.11upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | libservices/HOWTO | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/libservices/HOWTO b/libservices/HOWTO new file mode 100644 index 00000000..6a581bf2 --- /dev/null +++ b/libservices/HOWTO @@ -0,0 +1,103 @@ +Copyright (c) 2009 Sun Microsystems, Inc. + +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_ptr)(...); /* fix the prototype as appropriate */ + void (*foo_func2_ptr)(...); /* fix the prototype as appropriate */ + } *foo_service; + + #ifdef MYSQL_DYNAMIC_PLUGIN + + #define foo_func1(...) foo_service->foo_func1_ptr(...) + #define foo_func2(...) foo_service->foo_func2_ptr(...) + + #else + + int foo_func1(...); /* fix the prototype as appropriate */ + void foo_func2(...); /* 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/mysql/services.h +4. increase the minor plugin ABI version in include/mysql/plugin.h + (MARIA_PLUGIN_INTERFACE_VERSION = MARIA_PLUGIN_INTERFACE_VERSION+1) + don't forget to update test result! e.g. use something like + grep '\s\<1\.11\>' -r mysql-test +5. add the version of your service to include/service_versions.h: +================================================================== + #define VERSION_foo 0x0100 +================================================================== + +6. 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; +================================================================== + +7. add the new file to libservices/CMakeLists.txt (MYSQLSERVICES_SOURCES) +8. Add all new files to repository (git add) +9. and finally, register your service for dynamic linking in + sql/sql_plugin_services.ic as follows: +9.1 fill in the service structure: +================================================================== + static struct foo_service_st foo_handler = { + foo_func1, + foo_func2 + } +================================================================== + +9.2 and add it to the list of services + +================================================================== + { "foo_service", VERSION_foo, &foo_handler } +================================================================== + +that's all. + |