shiva::dll

plugins_registry:

Description

This class allows you to store plugin creation symbols through its template CreatorSignature parameter. Through this class you are able to retrieve the number of plugins, apply a functor on each of the symbols (as creates the plugin for example).

Diagram

plugins_registry API

Class Signature

template <typename CreatorSignature>
class plugins_registry;

Constructor

explicit plugins_registry(shiva::fs::path &&plugins_directory, const std::string library_pattern_matching) noexcept;

plugins_registry

Parameters

• plugins_directory represents the path to the directory containing the plugins

• library_pattern_matching represents a basic pattern to respect for libraries to load

For example if the pattern is [shiva-system] then only libraries that have [shiva-system] in their names will be loaded. [libshiva-system-plugin.so] will be loaded [libother-things.so] will not be loaded.

Functions

Functions Name	Description
load_all_symbols	load all symbols for plugins creation from the plugins_directory
nb_plugins	return the number of plugins
apply_on_each_symbols	apply a functor on each symbols

load_all_symbols

bool load_all_symbols() noexcept;

Return value

Possible name	Description
success	boolean true if all the symbols of all the libraries have been correctly loaded false if a symbol from one of the libraries was not loaded false if the plugins_directory doesn't exist

Example

bool success = plugins_registry.load_all_symbols();
if (!success) {
   /* The loading of symbols failed */
}

Notes

This function allows you to load symbols from the template to create the object. The symbols are loaded recursively from the folder you specified in the object's constructor.

If one of the symbols could not be correctly loaded the function does not stop and proceeds to load the next plugin. If when browsing folders a corrupted file is spotted the function switch to loading the next plugin.

nb_plugins

size_t nb_plugins() const noexcept;

Return value

Possible name	Description
nb_plugins	size_t numbers of plugins

Example

size_t nb_plugins = plugins_registry.nb_plugins();
if (nb_plugins < 4) {
    //! Oh no, i was exepcting at least 4 plugins
}

apply_on_each_symbols

template <typename TFunctor>
void apply_on_each_symbols(TFunctor &&functor);

Template parameters

Name	Description
functor	TFunctor represents the functor to apply on each of the loaded symbols.

Example

auto functor = [this](auto &&symbol) {
                auto res = symbol(/* parmeters for the creation of the object */);
                // res -> object created by the symbol creator
                // manipulate res or put it in a container for example.
                this->container_object.push_back(std::move(res));
            };

plugins_registry_.apply_on_each_symbols(functor);

Notes

• This function applies the functor as a parameter to each of the symbols that were previously loaded by the load_all_symbols function.

helpers

Functions Name	Description
is_shared_library	check if a specific path is a shared library

is_shared_library

static inline bool is_shared_library(const fs::path &path) noexcept;

Parameters

Name	Description
path	fs::path the path to be tested

Return value

Possible name	Description
result	boolean true if the path is a shared_library false otherwise

Example

// result is true
bool result = shiva::helpers::is_shared_library(shiva::fs::path("path/libfoo.so"));

// result is false
result = shiva::helpers::is_shared_library(shiva::fs::path("path/libbar"));

if (!result) {
   /* The path given as parameter doesn't seem's to be a shared_library */
}

Notes

• check if the path passed in parameter is a shared library