add spam server

example/spam.cpp

@@ -0,0 +1,122 @@
+/**
+ * Copyright - See the COPYRIGHT that is included with this distribution.
+ * pvxs is distributed subject to a Software License Agreement found
+ * in file LICENSE that is included with this distribution.
+ */
+
+#include <iostream>
+
+#include <epicsTime.h>
+
+#include <pvxs/source.h>
+#include <pvxs/server.h>
+#include <pvxs/nt.h>
+#include <pvxs/log.h>
+
+using namespace pvxs;
+
+DEFINE_LOGGER(app, "spam");
+
+namespace {
+
+struct SpamSource : public server::Source
+{
+    std::shared_ptr<std::set<std::string>> names;
+    Value initial;
+
+    SpamSource()
+        :names(std::make_shared<decltype (names)::element_type>())
+        ,initial(nt::NTScalar{TypeCode::UInt32}.create())
+    {}
+
+    // Source interface
+public:
+    virtual void onSearch(Search &op) override final
+    {
+        for(auto& pv :op) {
+            if(names->find(pv.name())!=names->end())
+                pv.claim();
+        }
+    }
+    virtual void onCreate(std::unique_ptr<server::ChannelControl> &&chan) override final
+    {
+        chan->onOp([this](std::unique_ptr<server::ConnectOp>&& cop) {
+            cop->onGet([](std::unique_ptr<server::ExecOp>&& op) {
+                op->error("Only monitor implemented");
+            });
+            cop->connect(initial);
+        });
+
+        chan->onSubscribe([this](std::unique_ptr<server::MonitorSetupOp>&& setup) {
+
+            std::shared_ptr<server::MonitorControlOp> sub(setup->connect(initial));
+
+            auto counter = std::make_shared<uint32_t>(0u);
+
+            auto fill = [this, sub, counter]() mutable {
+                Value update;
+                do {
+                    auto cnt = (*counter)++;
+                    update = initial.cloneEmpty();
+                    update["value"] = cnt;
+
+                    log_debug_printf(app, "%s count %u\n", sub->peerName().c_str(), unsigned(cnt));
+
+                }while(sub->tryPost(std::move(update)));
+            };
+
+            sub->onHighMark(fill);
+
+            sub->onStart([fill](bool start) mutable {
+                if(start)
+                    fill();
+            });
+
+            log_info_printf(app, "%s Subscribing\n", setup->peerName().c_str());
+        });
+    }
+    virtual List onList() override final
+    {
+        return List{names, false};
+    }
+};
+
+} // namespace
+
+int main(int argc, char* argv[])
+{
+    if(argc<=1) {
+        std::cerr<<"Usage: "<<argv[0]<<" <pvname>\n";
+        return 1;
+    }
+
+    // Read $PVXS_LOG from process environment and update
+    // logging configuration.  eg.
+    //    export PVXS_LOG=*=DEBUG
+    // makes a lot of noise.
+    logger_level_set(app.name, Level::Info);
+    logger_config_env();
+
+    auto src = std::make_shared<SpamSource>();
+    src->names->insert(argv[1]);
+
+    // Build server which will server this PV
+    // Configure using process environment.
+    server::Server serv = server::Config::from_env()
+            .build()
+            .addSource("spamsrc", src);
+
+    // (optional) Print the configuration this server is using
+    // with any auto-address list expanded.
+    std::cout<<"Effective config\n"<<serv.config();
+
+    std::cout<<"Running\n";
+
+    // Start server and run forever, or until Ctrl+c is pressed.
+    // Returns on SIGINT or SIGTERM
+    serv.run();
+
+    std::cout<<"Done\n";
+
+    return 0;
+}