zeek/auxil/broker/caf/examples/flow/spsc-buffer-resource.cpp
Patrick Kelley 8fd444092b initial
2025-05-07 15:35:15 -04:00

63 lines
1.8 KiB
C++

// Non-interactive example to illustrate how to connect flows over an
// asynchronous SPSC (Single Producer Single Consumer) buffer.
#include "caf/actor_system.hpp"
#include "caf/async/spsc_buffer.hpp"
#include "caf/caf_main.hpp"
#include "caf/event_based_actor.hpp"
#include "caf/scheduled_actor/flow.hpp"
#include <iostream>
namespace {
// --(rst-source-begin)--
// Simple source for generating a stream of integers from 1 to n.
void source(caf::event_based_actor* self,
caf::async::producer_resource<int> out, size_t n) {
self
// Get an observable factory.
->make_observable()
// Produce an integer sequence starting at 1, i.e., 1, 2, 3, ...
.from_callable([i = 0]() mutable { return ++i; })
// Only take the requested number of items from the infinite sequence.
.take(n)
// Subscribe the resource to the sequence, thereby starting the stream.
.subscribe(out);
}
// --(rst-source-end)--
// --(rst-sink-begin)--
// Simple sink for consuming a stream of integers, printing it to stdout.
void sink(caf::event_based_actor* self, caf::async::consumer_resource<int> in) {
self
// Get an observable factory.
->make_observable()
// Lift the input to an observable flow.
.from_resource(std::move(in))
// Print each integer.
.for_each([](int x) { std::cout << x << '\n'; });
}
// --(rst-sink-end)--
struct config : caf::actor_system_config {
config() {
opt_group{custom_options_, "global"} //
.add(n, "num-values,n", "number of values produced by the source");
}
size_t n = 100;
};
// --(rst-main-begin)--
void caf_main(caf::actor_system& sys, const config& cfg) {
auto [snk_res, src_res] = caf::async::make_spsc_buffer_resource<int>();
sys.spawn(sink, std::move(snk_res));
sys.spawn(source, std::move(src_res), cfg.n);
}
// --(rst-main-end)--
} // namespace
CAF_MAIN()