This extends the functionality of SDBUSCPP_REGISTER_STRUCT macro.
It now provides functionality for serializing a user-defined struct as an a{sv} dictionary, and for deserializing an a{sv} dictionary into a user-defined struct. The former one is achieved by decorating the struct with sdbus::as_dictionary(struct), the latter one is an automatic behavior -- when sdbus-c++ is asked to deserialize into a struct but the data in the message is of type a{sv}, then the dict-to-struct deserialization is performed automatically.
There are some aspects of behavior in the serialization/deserialization functionality that can be customized by the client. Newly introduced SDBUSCPP_ENABLE_NESTED_STRUCT2DICT_SERIALIZATION and SDBUSCPP_ENABLE_RELAXED_DICT2STRUCT_DESERIALIZATION macros serve the purpose.
Until now, the solution to ensure that even large messages are fully sent out has been to flush the connection queues after each sending of a message, which is likely an unnecessary call (with unnecessary cost) in vast majority of cases, and which may block the connection from doing other work until the large message is fully sent out. This was a rather quick, hacky workaround.
Now, after the sending the message we check whether it has been sent out fully or not. If not (outbound queues are non-empty), then we send a wake-up signal to the connection event loop. The event loop thread then fetches new sd-bus timeouts and events and will see that there are pending outbound messages to process, and will process them together with any other prospective pending events, until there is nothing to process (i.e., the outbound message has been fully dispatched).
This reorganizes the layers of abstraction in the sense how `Message` depends on `Connection` and vice versa. Now, `Message` has a link to the `Connection`. This replaces the shortcut link to the low-level `SdBus` interface that the `Message` kept. The interactions from `Message` now go through `Connection` which forwards them to `SdBus`. `Connection` is now a sole owner of the low-level `SdBus` interface. This allows for future changes around `SdBus` (e.g. a change from virtual functions back to non-virtual functions) without affecting the rest of the library. `Proxy`s and `Object`s can now send messages directly without having to go through `Connection`. The `Connection` no more depends on `Message` business-logic methods; it serves only as a factory for messages.
The flow for creating messages: `Proxy`/`Object` -> `Connection` -> `SdBus`
The flow for sending messages: (`Proxy`/`Object` ->) `Message` -> `Connection` -> `SdBus`
This also better reflects how dependencies are managed in the underlying sd-bus library.
Additionally, `getSdBusInterface()` methods are removed which was anyway planned, and improves the design by "Tell, don't ask" principle.
This refactoring is the necessary enabler for other upcoming improvements (regarding sending long messages, or creds refactoring, for example).
This fixes the template specialization ambiguity error when a signature_of applied upon a const (and/or volatile) enum type would render the const specialization and the enum specialization as two equally-ranked candidates.
This introduces SDBUSCPP_REGISTER_STRUCT macro that helps clients conveniently, in one line, teach sdbus-c++ to recognize and accept their custom C++ struct types wherever D-Bus structs are expected in a D-Bus API.
The macro saves some boilerplate that would otherwise be needed on client side for every registered struct.
Since sdbus-c++ knows types of D-Bus call/signal/property input/output parameters at compile time, why not assemble the D-Bus signature strings at compile time, too, instead of assembling them at run time as std::string with likely cost of (unnecessary) heap allocations...
std::array is well supported constexpr type in C++20, so we harness it to build the D-Bus signature string and store it into the binary at compile time.
This introduces strong types for `std::string`-based D-Bus types. This facilitates safer, less error-prone and more expressive API.
What previously was `auto proxy = createProxy("org.sdbuscpp.concatenator", "/org/sdbuscpp/concatenator");` is now written like `auto proxy = createProxy(ServiceName{"org.sdbuscpp.concatenator"}, ObjectPath{"/org/sdbuscpp/concatenator"});`.
These types are:
* `ObjectPath` type for the object path (the type has been around already but now is also used consistently in sdbus-c++ API for object path strings),
* `InterfaceName` type for D-Bus interface names,
* `BusName` (and its aliases `ServiceName` and `ConnectionName`) type for bus/service/connection names,
* `MemberName` (and its aliases `MethodName`, `SignalName` and `PropertyName`) type for D-Bus method, signal and property names,
* `Signature` type for the D-Bus signature (the type has been around already but now is also used consistently in sdbus-c++ API for signature strings),
* `Error::Name` type for D-Bus error names.
sd_bus_match_signal() is more convenient than more general sd_bus_add_match() for signal registration, and requires less code on our side. Plus, systemd of at least v238 is required for sdbus-c++ v2, and this version already ships with sd_bus_match_signal().
* feat: add support for direct connections
* refactor: simplify a bit, change comments, extend tests
* fix: compiler warning about unused variable
* docs: add section on direct connections to the tutorial
---------
Co-authored-by: Maksim Fedyarov <m.fedyarov@omp.ru>
Co-authored-by: Stanislav Angelovič <stanislav.angelovic@protonmail.com>
* feat: support serialization of array, span and unordered_map
* fix some spelling mistakes
* docs: update table of valid c++ types
---------
Co-authored-by: Marcel Hellwig <github@cookiesoft.de>
* Add methods to initiate custom session bus connection
The new function helper `createSessionBusConnectionWithAddress` allows to create connection to session bus with custom address.
Signed-off-by: Alexander Livenets <a.livenets@gmail.com>
* feat: add support for session bus connection at custom address
Co-authored-by: Stanislav Angelovic <stanislav.angelovic@siemens.com>
* Since ObjectPath and Signature have a user-declared copy-ctor and copy
assignment operator the implicit declaration of corresponding move
operations is disabled. Explicitly add defaulted versions so that
move operations actually move instead of copy.
* See: https://github.com/Kistler-Group/sdbus-cpp/issues/230
This internally calls sd_bus_open(), which automatically selects the
system or session bus connection based on the presence and
content of a DBUS_STARTER_BUS_TYPE environment variable and
whether the calling process has root privileges.
This option is very helpful when creating services and clients that will use the system bus in production, but connect to a session
for testing.
Additional changes:
* Removed assertions null-checking make_unique() return values.
make_unique() calls new, and new is expected to throw or abort
on failure, making the assertions unhelpful.
* Corrected a typo in the ClosesAndUnrefsBusWhenDestructed
unit test for the system bus (tested the wrong function).
* Add missing nullptr check in Message::peekType().
* According to its specification, sd_bus_message_peek_type() sets a
given contents parameter to NULL if the next element in a message is
not a container. Since assigning a nullptr to a std::string has
undefined behaviour (typically resulting in an invalid memory access),
Message::peekType() must not assign contentsSig unconditionally.
* sdbus-cpp: Add API to get message credentials
Signed-off-by: Alexander Livenets <a.livenets@gmail.com>
* fix: add <sys/types.h> include for gid_t and other types
Co-authored-by: Stanislav Angelovič <angelovic.s@gmail.com>
The underlying bus was thread_local, but the design assumption that Variants built on top of that instance won't outlive the thread was incorrect. In stress tests, Variants were moved (and this is completely legal) to a different thread.
Stanislav Angelovič
Stanislav Angelovic
Anthony Brandon
Marcel Hellwig
alivenetsandStanislav Angelovic
Benjamin Kaufmann
David Leeds
lubo-svk