MXS-2218 Add showing and to_json functionality

include/maxscale/mainworker.hh

@@ -45,6 +45,9 @@ public:
     void add_task(const char* zName, TASKFN func, void* pData, int frequency);
     void remove_task(const char* zName);
 
+    void show_tasks(DCB* pDcb) const;
+    json_t* tasks_to_json(const char* zhost) const;
+
 private:
     bool pre_run() override;
     void post_run() override;
@@ -53,10 +56,12 @@ private:
     struct Task
     {
     public:
-        Task(const char* zName, TASKFN func, void* pData)
+        Task(const char* zName, TASKFN func, void* pData, int frequency)
             : name(zName)
             , func(func)
             , pData(pData)
+            , frequency(frequency)
+            , nextdue(time(0) + frequency)
             , id(0)
         {
         };
@@ -64,6 +69,8 @@ private:
         std::string name;
         TASKFN      func;
         void*       pData;
+        int         frequency;
+        time_t      nextdue;
         uint32_t    id;
     };
 

server/core/mainworker.cc

@@ -13,6 +13,7 @@
 
 #include <maxscale/mainworker.hh>
 #include <signal.h>
+#include <maxscale/config.hh>
 
 namespace
 {
@@ -54,7 +55,7 @@ void MainWorker::add_task(const char* zName, TASKFN func, void* pData, int frequ
     call([=]() {
             mxb_assert(m_tasks_by_name.find(zName) == m_tasks_by_name.end());
 
-            Task task(zName, func, pData);
+            Task task(zName, func, pData, frequency);
 
             auto p = m_tasks_by_name.insert(std::make_pair(std::string(zName), task));
             Task& inserted_task = (*p.first).second;
@@ -84,6 +85,65 @@ void MainWorker::remove_task(const char* zName)
         EXECUTE_AUTO);
 }
 
+void MainWorker::show_tasks(DCB* pDcb) const
+{
+    // TODO: Make call() const.
+    MainWorker* pThis = const_cast<MainWorker*>(this);
+    pThis->call([this, pDcb] () {
+            dcb_printf(pDcb, "%-25s | Frequency | Next Due\n", "Name");
+            dcb_printf(pDcb, "--------------------------+-----------+-------------------------\n");
+
+            for (auto it = m_tasks_by_name.begin(); it != m_tasks_by_name.end(); ++it)
+            {
+                const Task& task = it->second;
+
+                struct tm tm;
+                char buf[40];
+                localtime_r(&task.nextdue, &tm);
+                asctime_r(&tm, buf);
+                dcb_printf(pDcb, "%-25s | %-9d | %s", task.name.c_str(), task.frequency, buf);
+            }
+        },
+        EXECUTE_AUTO);
+}
+
+json_t* MainWorker::tasks_to_json(const char* zHost) const
+{
+    json_t* pResult = json_array();
+
+    // TODO: Make call() const.
+    MainWorker* pThis = const_cast<MainWorker*>(this);
+    pThis->call([this, zHost, pResult]() {
+            for (auto it = m_tasks_by_name.begin(); it != m_tasks_by_name.end(); ++it)
+            {
+                const Task& task = it->second;
+
+                struct tm tm;
+                char buf[40];
+                localtime_r(&task.nextdue, &tm);
+                asctime_r(&tm, buf);
+                char* nl = strchr(buf, '\n');
+                mxb_assert(nl);
+                *nl = '\0';
+
+                json_t* pObject = json_object();
+
+                json_object_set_new(pObject, CN_ID, json_string(task.name.c_str()));
+                json_object_set_new(pObject, CN_TYPE, json_string("tasks"));
+
+                json_t* pAttrs = json_object();
+                json_object_set_new(pAttrs, "frequency", json_integer(task.frequency));
+                json_object_set_new(pAttrs, "next_execution", json_string(buf));
+
+                json_object_set_new(pObject, CN_ATTRIBUTES, pAttrs);
+                json_array_append_new(pResult, pObject);
+            }
+        },
+        EXECUTE_AUTO);
+
+    return pResult;
+}
+
 bool MainWorker::pre_run()
 {
     return true;
@@ -107,7 +167,11 @@ bool MainWorker::call_task(Worker::Call::action_t action, MainWorker::Task* pTas
 
         call_again = pTask->func(pTask->pData);
 
-        if (!call_again)
+        if (call_again)
+        {
+            pTask->nextdue = time(0) + pTask->frequency;
+        }
+        else
         {
             auto it = m_tasks_by_name.find(pTask->name);