Complete refactor of project file structure

Fix incorrect handing of default node parameters in SSD subscription.
Fix unable to parse some Clash rule-providers (#289).
Fix not filtering inline comments in some Surge rulesets. (#285)
Add Cron task options.
Add clean context option for persisting a JS context across the whole request.
Replace JS engine with QuickJS.

src/script/cron.cpp

@@ -0,0 +1,135 @@
+#include <string>
+#include <iostream>
+#include <libcron/Cron.h>
+
+#include "../handler/interfaces.h"
+#include "../handler/multithread.h"
+#include "../server/webserver.h"
+#include "../utils/logger.h"
+#include "../utils/rapidjson_extra.h"
+#include "../utils/system.h"
+#include "script_quickjs.h"
+
+extern bool gEnableCron;
+extern string_array gCronTasks;
+extern std::string gProxyConfig, gAccessToken;
+extern int gCacheConfig;
+
+libcron::Cron cron;
+
+static std::string parseProxy(const std::string &source)
+{
+    std::string proxy = source;
+    if(source == "SYSTEM")
+        proxy = getSystemProxy();
+    else if(source == "NONE")
+        proxy = "";
+    return proxy;
+}
+
+struct script_info
+{
+    std::string name;
+    time_t begin_time = 0;
+    time_t timeout = 0;
+};
+
+int timeout_checker(JSRuntime *rt, void *opaque)
+{
+    script_info info = *((script_info*)opaque);
+    if(info.timeout != 0 && time(NULL) >= info.begin_time + info.timeout) /// timeout reached
+    {
+        writeLog(0, "Script '" + info.name + "' has exceeded timeout " + std::to_string(info.timeout) + ", terminate now.", LOG_LEVEL_WARNING);
+        return 1;
+    }
+    return 0;
+}
+
+void refresh_schedule()
+{
+    cron.clear_schedules();
+    for(std::string &x : gCronTasks)
+    {
+        string_array arguments = split(x, "`");
+        if(arguments.size() < 3)
+            continue;
+        std::string &name = arguments[0], &cronexp = arguments[1], &path = arguments[2];
+        cron.add_schedule(name, cronexp, [=](auto &)
+        {
+            qjs::Runtime runtime;
+            qjs::Context context(runtime);
+            try
+            {
+                script_runtime_init(runtime);
+                script_context_init(context);
+                defer(script_cleanup(context);)
+                std::string proxy = parseProxy(gProxyConfig);
+                std::string script = fetchFile(path, proxy, gCacheConfig);
+                if(script.empty())
+                {
+                    writeLog(0, "Script '" + name + "' run failed: file is empty or not exist!", LOG_LEVEL_WARNING);
+                    return;
+                }
+                script_info info;
+                if(arguments.size() >= 4 && !arguments[3].empty())
+                {
+                    info.begin_time = time(NULL);
+                    info.timeout = to_int(arguments[3], 0);
+                    info.name = name;
+                    JS_SetInterruptHandler(JS_GetRuntime(context.ctx), timeout_checker, &info);
+                }
+                context.eval(script);
+            }
+            catch (qjs::exception)
+            {
+                script_print_stack(context);
+            }
+        });
+    }
+}
+
+std::string list_cron_schedule(RESPONSE_CALLBACK_ARGS)
+{
+    std::string &argument = request.argument;
+    std::string token = getUrlArg(argument, "token");
+    rapidjson::StringBuffer sb;
+    rapidjson::Writer<rapidjson::StringBuffer> writer(sb);
+    writer.StartObject();
+    if(token != gAccessToken)
+    {
+        response.status_code = 403;
+        writer.Key("code");
+        writer.Int(403);
+        writer.Key("data");
+        writer.String("Unauthorized");
+        writer.EndObject();
+        return sb.GetString();
+    }
+    writer.Key("code");
+    writer.Int(200);
+    writer.Key("tasks");
+    writer.StartArray();
+    for(std::string &x : gCronTasks)
+    {
+        string_array arguments = split(x, "`");
+        if(arguments.size() < 3)
+            continue;
+        writer.StartObject();
+        std::string &name = arguments[0], &cronexp = arguments[1], &path = arguments[2];
+        writer.Key("name");
+        writer.String(name.data());
+        writer.Key("cronexp");
+        writer.String(cronexp.data());
+        writer.Key("path");
+        writer.String(path.data());
+        writer.EndObject();
+    }
+    writer.EndArray();
+    writer.EndObject();
+    return sb.GetString();
+}
+
+size_t cron_tick()
+{
+    return cron.tick();
+}