builtins.h File Reference

The actions every A11 peer answers, whatever it was built to do. More...

#include <string>
#include <string_view>
#include <vector>
#include <absl/base/nullability.h>
#include "a11/actions/action.h"
#include "a11/actions/schema.h"

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Classes
struct	a11::actions::BuiltinAction
	A schema and handler pair the registry resolves without holding. More...

Namespaces
namespace	a11
namespace	a11::actions

Functions
bool	a11::actions::IsBuiltinAction (std::string_view name)
	Whether name is a builtin every registry answers for.
const BuiltinAction *absl_nullable	a11::actions::GetBuiltinAction (std::string_view name)
	The builtin named name, or null.
const std::vector< std::string > &	a11::actions::BuiltinActionNames ()
	Every builtin's name, sorted.

Variables
constexpr std::string_view	a11::actions::kListActionsName = "__list_actions__"
	Lists the actions a peer serves, with their schemas.
constexpr std::string_view	a11::actions::kGetSchemaName = "__get_schema__"
	Returns one action's schema, or NotFound.
constexpr std::string_view	a11::actions::kPingName = "__ping"
	Echoes a value, so a caller can tell A11 from anything holding a port.

Detailed Description

The actions every A11 peer answers, whatever it was built to do.

Why these are not registrations. A peer that cannot be asked what it serves has to be told, and telling is what four hand-copied handshakes were for. So discovery cannot be something an application remembers to install: it has to hold for a registry nobody configured, for a registry a service copied per connection, and for a registry an application has since called Unregister all over. That rules out being an entry in

a11::actions::ActionRegistry – <tt>Register</tt> replaces and <tt>Unregister</tt> removes

and it rules out a service-level install, because every client builds its own bare registry and would have nothing.

What holds instead is a table here, consulted by the registry on a miss. So ActionRegistry() is still empty of anything an application put there, while every lookup, every listing, and every Flow call resolves these three.

The handlers reach their registry through a11::actions::Action::GetRegistry rather than capturing one, which is what keeps this a function-local static and not a cycle from a registry to a handler that owns it.