Use better singleton default pattern

src/defi-cli.cpp

@@ -136,6 +136,8 @@ static int AppInitRPC(int argc, char* argv[])
         tfm::format(std::cerr, "Error reading configuration file: %s\n", error.c_str());
         return EXIT_FAILURE;
     }
+    RPCMetadata::InitFromArgs(gArgs);
+
     // Check for -testnet or -regtest parameter (BaseParams() calls are only valid after this clause)
     try {
         SelectBaseParams(gArgs.GetChainName());

src/init.cpp

@@ -1488,6 +1488,7 @@ bool AppInitMain(InitInterfaces& interfaces)
 
     InitSignatureCache();
     InitScriptExecutionCache();
+    RPCMetadata::InitFromArgs(gArgs);
 
     int script_threads = gArgs.GetArg("-par", DEFAULT_SCRIPTCHECK_THREADS);
     if (script_threads <= 0) {

src/masternodes/coinselect.h

@@ -21,30 +21,43 @@ static const std::string& ARG_STR_WALLET_COIN_OPT_SKIP_SOLVABLE = "-walletcoinop
 static const std::string& ARG_STR_WALLET_COIN_OPT_EAGER_SELECT = "-walletcoinopteagerselect";
 
 struct CoinSelectionOptions {
-    private:
-        std::optional<bool> fastSelect{};
-        std::optional<bool> skipSolvable{};
-        std::optional<bool> eagerSelect{};
+private:
+    std::optional<bool> fastSelect{};
+    std::optional<bool> skipSolvable{};
+    std::optional<bool> eagerSelect{};
 
-    public:
+    inline static std::unique_ptr<CoinSelectionOptions> DEFAULT;
+
+public:
     bool IsFastSelectEnabled() const { return fastSelect.value_or(false); }
     bool IsSkipSolvableEnabled() const { return skipSolvable.value_or(false); }
     bool IsEagerSelectEnabled() const { return eagerSelect.value_or(false); }
 
+    static void LogValues(const CoinSelectionOptions& m) {
+        struct V { const std::optional<bool> v; const std::string& arg; };
+        for (auto &[v, arg]: std::vector<V> { 
+            { m.fastSelect, ARG_STR_WALLET_FAST_SELECT },
+            { m.skipSolvable, ARG_STR_WALLET_COIN_OPT_SKIP_SOLVABLE },
+            { m.eagerSelect, ARG_STR_WALLET_COIN_OPT_EAGER_SELECT },
+        }) {
+            if (v) LogPrintf("conf: %s: %s\n", arg.substr(1), *v ? "true" : "false");
+        }
+    }
+
     static void SetupArgs(ArgsManager& args) {
         args.AddArg(ARG_STR_WALLET_FAST_SELECT, strprintf("Faster coin select - Enables walletcoinoptskipsolvable and walletcoinopteagerselect. This ends up in faster selection but has the disadvantage of not being able to pick complex input scripts (default: %u)", DEFAULT_COIN_SELECT_FAST_SELECT), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
         args.AddArg(ARG_STR_WALLET_COIN_OPT_SKIP_SOLVABLE, strprintf("Coin select option: Skips IsSolvable signable UTXO check (default: %u)", DEFAULT_COIN_SELECT_SKIP_SOLVABLE), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
         args.AddArg(ARG_STR_WALLET_COIN_OPT_EAGER_SELECT, strprintf("Coin select option: Take fast path and eagerly exit on match even without having through the entire set (default: %u)", DEFAULT_COIN_SELECT_EAGER_SELECT), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     }
 
-    static CoinSelectionOptions CreateDefault() {
-        CoinSelectionOptions opts;
-        FromArgs(opts, gArgs);
-        return opts;
+    static void InitFromArgs(const ArgsManager& args) {
+        auto m = std::make_unique<CoinSelectionOptions>();
+        FromArgs(*m, args);
+        LogValues(*m);
+        CoinSelectionOptions::DEFAULT = std::move(m);
     }
 
-
-    static void FromArgs(CoinSelectionOptions& m, ArgsManager& args) {
+    static void FromArgs(CoinSelectionOptions& m, const ArgsManager& args) {
         struct V {
             std::optional<bool>& target;
             const std::string& arg;
@@ -66,6 +79,14 @@ struct CoinSelectionOptions {
         }
     }
 
+    static CoinSelectionOptions CreateDefault() {
+        // Default to basic init, so tests, benches or other scenarios
+        // before init still falls back to expected.        
+        if (DEFAULT == nullptr) return CoinSelectionOptions{};
+        // Create a copy
+        return *DEFAULT;
+    }
+
     static void FromHTTPHeader(CoinSelectionOptions &m, const HTTPHeaderQueryFunc headerFunc) {
         struct V {
             std::optional<bool>& target;

src/rpc/request.h

@@ -30,20 +30,25 @@ struct RPCMetadata {
     public:
     CoinSelectionOptions coinSelectOpts;
 
-    static RPCMetadata CreateDefault() {
-        RPCMetadata m;
-        FromArgs(m, gArgs);
-        return m;
-    }
 
     static void SetupArgs(ArgsManager& args) {
         CoinSelectionOptions::SetupArgs(args);
     }
 
-    static void FromArgs(RPCMetadata &m, ArgsManager& args) {
+    static void InitFromArgs(const ArgsManager& args) {
+        CoinSelectionOptions::InitFromArgs(args);
+    }
+
+    static void FromArgs(RPCMetadata &m, const ArgsManager& args) {
         CoinSelectionOptions::FromArgs(m.coinSelectOpts, args);
     }
 
+    static RPCMetadata CreateDefault() {
+        return RPCMetadata {
+            CoinSelectionOptions::CreateDefault(),
+        };
+    }
+
     static void FromHTTPHeader(RPCMetadata &m, const HTTPHeaderQueryFunc headerFunc) {
         CoinSelectionOptions::FromHTTPHeader(m.coinSelectOpts, headerFunc);
     }