void subscribe_to(collection_type st)
{
auto state = this->shared_from_this();
collectionLifetime = composite_subscription();
// when the out observer is unsubscribed all the
// inner subscriptions are unsubscribed as well
auto innercstoken = state->out.add(collectionLifetime);
collectionLifetime.add(make_subscription([state, innercstoken](){
state->out.remove(innercstoken);
}));
auto selectedSource = on_exception(
[&](){return state->coordinator.in(std::move(st));},
state->out);
if (selectedSource.empty()) {
return;
}
// this subscribe does not share the out subscription
// so that when it is unsubscribed the out will continue
auto sinkInner = make_subscriber<value_type>(
state->out,
collectionLifetime,
// on_next
[state, st](value_type ct) {
state->out.on_next(ct);
},
// on_error
[state](std::exception_ptr e) {
state->out.on_error(e);
},
//on_completed
[state](){
if (!state->selectedCollections.empty()) {
auto value = state->selectedCollections.front();
state->selectedCollections.pop_front();
state->collectionLifetime.unsubscribe();
state->subscribe_to(value);
} else if (!state->sourceLifetime.is_subscribed()) {
state->out.on_completed();
}
}
);
auto selectedSinkInner = on_exception(
[&](){return state->coordinator.out(sinkInner);},
state->out);
if (selectedSinkInner.empty()) {
return;
}
selectedSource->subscribe(std::move(selectedSinkInner.get()));
}
int main (int argc, char const *argv[])
{
signal(SIGINT, stros_stop);
ros_node_t* node = stros_init_node("/dummy",argv[1]);
// subscribe
subscribe_to( node,"/chatter",MSG_STRING,callback);
stros_node_deploy(node);
printf("Finish deploy\n");
spin();
return 0;
}
void on_subscribe(Subscriber scbr) const {
static_assert(is_subscriber<Subscriber>::value, "subscribe must be passed a subscriber");
typedef Subscriber output_type;
struct concat_state_type
: public std::enable_shared_from_this<concat_state_type>
, public values
{
concat_state_type(values i, coordinator_type coor, output_type oarg)
: values(std::move(i))
, sourceLifetime(composite_subscription::empty())
, collectionLifetime(composite_subscription::empty())
, coordinator(std::move(coor))
, out(std::move(oarg))
{
}
void subscribe_to(collection_type st)
{
auto state = this->shared_from_this();
collectionLifetime = composite_subscription();
// when the out observer is unsubscribed all the
// inner subscriptions are unsubscribed as well
auto innercstoken = state->out.add(collectionLifetime);
collectionLifetime.add(make_subscription([state, innercstoken](){
state->out.remove(innercstoken);
}));
auto selectedSource = on_exception(
[&](){return state->coordinator.in(std::move(st));},
state->out);
if (selectedSource.empty()) {
return;
}
// this subscribe does not share the out subscription
// so that when it is unsubscribed the out will continue
auto sinkInner = make_subscriber<value_type>(
state->out,
collectionLifetime,
// on_next
[state, st](value_type ct) {
state->out.on_next(ct);
},
// on_error
[state](std::exception_ptr e) {
state->out.on_error(e);
},
//on_completed
[state](){
if (!state->selectedCollections.empty()) {
auto value = state->selectedCollections.front();
state->selectedCollections.pop_front();
state->collectionLifetime.unsubscribe();
state->subscribe_to(value);
} else if (!state->sourceLifetime.is_subscribed()) {
state->out.on_completed();
}
}
);
auto selectedSinkInner = on_exception(
[&](){return state->coordinator.out(sinkInner);},
state->out);
if (selectedSinkInner.empty()) {
return;
}
selectedSource->subscribe(std::move(selectedSinkInner.get()));
}
composite_subscription sourceLifetime;
composite_subscription collectionLifetime;
std::deque<collection_type> selectedCollections;
coordinator_type coordinator;
output_type out;
};
auto coordinator = initial.coordination.create_coordinator(scbr.get_subscription());
// take a copy of the values for each subscription
auto state = std::shared_ptr<concat_state_type>(new concat_state_type(initial, std::move(coordinator), std::move(scbr)));
state->sourceLifetime = composite_subscription();
// when the out observer is unsubscribed all the
// inner subscriptions are unsubscribed as well
state->out.add(state->sourceLifetime);
auto source = on_exception(
[&](){return state->coordinator.in(state->source);},
state->out);
if (source.empty()) {
return;
}
// this subscribe does not share the observer subscription
// so that when it is unsubscribed the observer can be called
// until the inner subscriptions have finished
auto sink = make_subscriber<collection_type>(
state->out,
state->sourceLifetime,
// on_next
[state](collection_type st) {
if (state->collectionLifetime.is_subscribed()) {
state->selectedCollections.push_back(st);
} else if (state->selectedCollections.empty()) {
state->subscribe_to(st);
}
},
// on_error
[state](std::exception_ptr e) {
state->out.on_error(e);
},
// on_completed
[state]() {
if (!state->collectionLifetime.is_subscribed() && state->selectedCollections.empty()) {
state->out.on_completed();
}
}
);
auto selectedSink = on_exception(
[&](){return state->coordinator.out(sink);},
state->out);
if (selectedSink.empty()) {
return;
}
source->subscribe(std::move(selectedSink.get()));
}
