stats: fetch all arguments needed when constructing g_stats_client

There's little sense in passing a ref to `ArgsManager` just to set a few
values because we'll be `const`-ing them in an upcoming commit.
Arguments supplied are expected to last the lifetime of the program's
instance and there's little reason to keep re-fetching those values.

src/init.cpp

@@ -1528,7 +1528,11 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     // We need to initialize g_stats_client early as currently, g_stats_client is called
     // regardless of whether transmitting stats are desirable or not and if
     // g_stats_client isn't present when that attempt is made, the client will crash.
-    ::g_stats_client = std::make_unique<statsd::StatsdClient>();
+    ::g_stats_client = std::make_unique<statsd::StatsdClient>(args.GetArg("-statshost", DEFAULT_STATSD_HOST),
+                                                              args.GetArg("-statshostname", DEFAULT_STATSD_HOSTNAME),
+                                                              args.GetArg("-statsport", DEFAULT_STATSD_PORT),
+                                                              args.GetArg("-statsns", DEFAULT_STATSD_NAMESPACE),
+                                                              args.GetBoolArg("-statsenabled", DEFAULT_STATSD_ENABLE));
 
     {
 

src/statsd_client.cpp

@@ -74,11 +74,12 @@ struct _StatsdClientData {
     char    errmsg[1024];
 };
 
-StatsdClient::StatsdClient(const std::string& host, int port, const std::string& ns) :
+StatsdClient::StatsdClient(const std::string& host, const std::string& nodename, int port, const std::string& ns,
-    d(std::make_unique<_StatsdClientData>())
+                           bool enabled)
+    : d{std::make_unique<_StatsdClientData>()}, m_enabled{enabled}
 {
     d->sock = INVALID_SOCKET;
-    config(host, port, ns);
+    config(host, nodename, port, ns);
 }
 
 StatsdClient::~StatsdClient()
@@ -87,10 +88,11 @@ StatsdClient::~StatsdClient()
     CloseSocket(d->sock);
 }
 
-void StatsdClient::config(const std::string& host, int port, const std::string& ns)
+void StatsdClient::config(const std::string& host, const std::string& nodename, int port, const std::string& ns)
 {
     d->ns = ns;
     d->host = host;
+    d->nodename = nodename;
     d->port = port;
     d->init = false;
     CloseSocket(d->sock);
@@ -98,13 +100,8 @@ void StatsdClient::config(const std::string& host, int port, const std::string&
 
 int StatsdClient::init()
 {
-    static bool fEnabled = gArgs.GetBoolArg("-statsenabled", DEFAULT_STATSD_ENABLE);
-    if (!fEnabled) return -3;
-
     if ( d->init ) return 0;
 
-    config(gArgs.GetArg("-statshost", DEFAULT_STATSD_HOST), gArgs.GetArg("-statsport", DEFAULT_STATSD_PORT), gArgs.GetArg("-statsns", DEFAULT_STATSD_NAMESPACE));
-
     d->sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
     if ( d->sock == INVALID_SOCKET ) {
         snprintf(d->errmsg, sizeof(d->errmsg), "could not create socket, err=%m");
@@ -121,10 +118,6 @@ int StatsdClient::init()
         return -2;
     }
 
-    if (gArgs.IsArgSet("-statshostname")) {
-        d->nodename = gArgs.GetArg("-statshostname", DEFAULT_STATSD_HOSTNAME);
-    }
-
     d->init = true;
     return 0;
 }
@@ -226,6 +219,9 @@ int StatsdClient::sendDouble(std::string key, double value, const std::string& t
 
 int StatsdClient::send(const std::string& message)
 {
+    if (!m_enabled)
+        return -3;
+
     int ret = init();
     if ( ret )
     {

src/statsd_client.h

@@ -25,12 +25,13 @@ struct _StatsdClientData;
 
 class StatsdClient {
     public:
-        explicit StatsdClient(const std::string& host = DEFAULT_STATSD_HOST, int port = DEFAULT_STATSD_PORT, const std::string& ns = DEFAULT_STATSD_NAMESPACE);
+        explicit StatsdClient(const std::string& host, const std::string& nodename, int port, const std::string& ns,
+                              bool enabled);
         ~StatsdClient();
 
     public:
         // you can config at anytime; client will use new address (useful for Singleton)
-        void config(const std::string& host, int port, const std::string& ns = DEFAULT_STATSD_NAMESPACE);
+        void config(const std::string& host, const std::string& nodename, int port, const std::string& ns);
         const char* errmsg();
 
     public:
@@ -62,6 +63,9 @@ class StatsdClient {
 
     protected:
         const std::unique_ptr<struct _StatsdClientData> d;
+
+    private:
+        const bool m_enabled{false};
 };
 
 } // namespace statsd

src/test/util/setup_common.cpp

@@ -183,7 +183,13 @@ BasicTestingSetup::BasicTestingSetup(const std::string& chainName, const std::ve
     SetupNetworking();
     InitSignatureCache();
     InitScriptExecutionCache();
-    ::g_stats_client = std::make_unique<statsd::StatsdClient>();
+    ::g_stats_client = std::make_unique<statsd::StatsdClient>(
+        m_node.args->GetArg("-statshost", DEFAULT_STATSD_HOST),
+        m_node.args->GetArg("-statshostname", DEFAULT_STATSD_HOSTNAME),
+        m_node.args->GetArg("-statsport", DEFAULT_STATSD_PORT),
+        m_node.args->GetArg("-statsns", DEFAULT_STATSD_NAMESPACE),
+        m_node.args->GetBoolArg("-statsenabled", DEFAULT_STATSD_ENABLE)
+    );
     m_node.chain = interfaces::MakeChain(m_node);
 
     m_node.netgroupman = std::make_unique<NetGroupManager>(/*asmap=*/std::vector<bool>());