Implement changesettings

src/rpc/misc.cpp

@@ -96,3 +96,96 @@ UniValue listsettings(const UniValue& params, bool fHelp)
     return gArgs.OutputArgs();
 }
 
+UniValue changesettings(const UniValue& params, bool fHelp)
+{
+    if (fHelp || params.size() < 1)
+    {
+        throw runtime_error(
+                    "changesettings\n"
+                    );
+    }
+
+    UniValue result(UniValue::VOBJ);
+    UniValue settings_stored_with_no_state_change(UniValue::VARR);
+    UniValue settings_immediate(UniValue::VARR);
+    UniValue settings_applied_requiring_restart(UniValue::VARR);
+    UniValue invalid_settings_ignored(UniValue::VARR);
+
+    bool restart_required = false;
+
+    for (unsigned int i = 0; i < params.size(); ++i)
+    {
+        std::string param = params[i].get_str();
+        if (param.size() > 0 && param[0] == '-')
+        {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Incorrectly formatted setting change: " + param);
+        }
+
+        std::string::size_type pos;
+        std::string name;
+        std::string value;
+
+        if ((pos = param.find('=')) != std::string::npos)
+        {
+            name = param.substr(0, pos);
+            value = param.substr(pos + 1);
+        }
+        else
+        {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Incorrectly formatted setting change: " + param);
+        }
+
+        std::optional<unsigned int> flags = gArgs.GetArgFlags('-' + name);
+
+        // Do not process if not a valid argument/setting. This is different than incorrect format. This means the arg
+        // is not in the args list from AddArg.
+        if (!flags)
+        {
+            invalid_settings_ignored.push_back(param);
+            continue;
+        }
+
+        // TODO: Record explicit default state for settings.
+        // This currently has a problem that I am not sure yet how to solve. Settings that are defaulted to true, unless
+        // they are set to the contrary, such as -staking, will falsely indicate a change because the defaulted state is
+        // not explicitly stored for comparison. After there is an explicit entry defined in the settings file, it works
+        // correctly.
+        bool value_changed = (gArgs.GetArg("-" + name, "never_used_default") != value);
+        bool immediate_effect = *flags & ArgsManager::IMMEDIATE_EFFECT;
+
+        // Regardless, store in r-w settings file.
+        if (!updateRwSetting(name, value))
+        {
+            throw JSONRPCError(RPC_MISC_ERROR, "Error storing setting in read-write settings file.");
+        }
+
+        if (value_changed)
+        {
+            gArgs.ForceSetArg("-" + name, value);
+
+            if (immediate_effect)
+            {
+                settings_immediate.push_back(param);
+            }
+            else
+            {
+                settings_applied_requiring_restart.push_back(param);
+
+                // Record if restart required.
+                restart_required |= !immediate_effect;
+            }
+        }
+        else
+        {
+            settings_stored_with_no_state_change.push_back(param);
+        }
+    }
+
+    result.pushKV("settings_change_requires_restart", restart_required);
+    result.pushKV("settings_stored_with_no_state_change", settings_stored_with_no_state_change);
+    result.pushKV("settings_changed_taking_immediate_effect", settings_immediate);
+    result.pushKV("settings_changed_requiring_restart", settings_applied_requiring_restart);
+
+    return result;
+}
+

src/rpc/server.cpp

@@ -366,6 +366,7 @@ static const CRPCCommand vRPCCommands[] =
     { "auditsnapshotaccrual",    &auditsnapshotaccrual,    cat_developer     },
     { "auditsnapshotaccruals",   &auditsnapshotaccruals,   cat_developer     },
     { "addkey",                  &addkey,                  cat_developer     },
+    { "changesettings",          &changesettings,          cat_developer     },
     { "currentcontractaverage",  &currentcontractaverage,  cat_developer     },
     { "debug",                   &debug,                   cat_developer     },
     { "dumpcontracts",           &dumpcontracts,           cat_developer     },

src/rpc/server.h

@@ -221,6 +221,7 @@ extern UniValue scraperreport(const UniValue& params, bool fHelp);
 // Network
 extern UniValue addnode(const UniValue& params, bool fHelp);
 extern UniValue askforoutstandingblocks(const UniValue& params, bool fHelp);
+extern UniValue changesettings(const UniValue& params, bool fHelp);
 extern UniValue clearbanned(const UniValue& params, bool fHelp);
 extern UniValue currenttime(const UniValue& params, bool fHelp);
 extern UniValue getaddednodeinfo(const UniValue& params, bool fHelp);