external services

src/main/java/app/controllers/StatsController.java

@@ -3,6 +3,7 @@ package app.controllers;
 import app.annotations.interfaces.BurstUpdatePlayers;
 import app.annotations.interfaces.CollectStatistic;
 import app.entities.Stats;
+import app.services.ExternalServices;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
@@ -17,10 +18,12 @@ import java.util.List;
 @RequestMapping("api/stats")
 public class StatsController {
     private Stats stats;
+    private ExternalServices externalServices;
 
     @Autowired
-    public StatsController(Stats stats){
+    public StatsController(Stats stats, ExternalServices externalServices){
         this.stats = stats;
+        this.externalServices = externalServices;
     }
 
     @GetMapping
@@ -32,4 +35,10 @@ public class StatsController {
         }
         return new ResponseEntity<>(stats, HttpStatus.OK);
     }
+
+    @GetMapping("/services")
+    @CollectStatistic
+    public ResponseEntity GetServices() {
+        return new ResponseEntity(externalServices.getServices(), HttpStatus.OK);
+    }
 }

src/main/java/app/services/ExternalServices.java

@@ -0,0 +1,53 @@
+package app.services;
+
+import app.services.db.DBService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.time.Instant;
+import java.util.HashMap;
+
+@Service
+public class ExternalServices {
+    private HashMap<String, Long> services;
+    private DBService dbService;
+    private long last_db_update = 0L;
+    private final long refresh = 60L;
+
+    @Autowired
+    ExternalServices(DBService dbService) {
+        this.dbService = dbService;
+        this.services = new HashMap<>();
+    }
+
+    public HashMap<String, Boolean> getServices() {
+        update();
+        HashMap<String, Boolean> s = new HashMap<>();
+        services.forEach((key, utime) -> {
+            if (Instant.now().getEpochSecond() - utime < refresh) s.put(key, true);
+            else s.put(key, false);
+        });
+        return s;
+    }
+
+    public void update() {
+        if (Instant.now().getEpochSecond() - last_db_update < refresh / 3)
+            return;
+
+        try {
+            services.put("db_main", dbService.getMainServerTime());
+        } catch (Exception e) {
+            services.put("db_main", 0L);
+        }
+
+        try {
+            services.put("db_replica", dbService.getReplicaServerTime());
+        } catch (Exception e) {
+            services.put("db_replica", 0L);
+        }
+    }
+
+    public void update(String name) {
+        services.put(name, Instant.now().getEpochSecond());
+    }
+}

src/main/java/app/services/db/DBService.java

@@ -22,10 +22,18 @@ public class DBService {
     }
 
     public Long getDBServerTime() {
-        Long rw_time = (Long) entityManager_rw.createNativeQuery("SELECT UNIX_TIMESTAMP()")
+        Long rw_time = getMainServerTime();
+        Long ro_time = getReplicaServerTime();
+        return rw_time;
+    }
+
+    public Long getMainServerTime() {
+        return (Long) entityManager_rw.createNativeQuery("SELECT UNIX_TIMESTAMP()")
                 .getSingleResult();
-        Long ro_time = (Long) entityManager_ro.createNativeQuery("SELECT UNIX_TIMESTAMP()")
+    }
+
+    public Long getReplicaServerTime() {
+        return (Long) entityManager_ro.createNativeQuery("SELECT UNIX_TIMESTAMP()")
                 .getSingleResult();
-        return rw_time;
     }
 }

src/main/java/app/websocket/handlers/ExternalServicesHandler.java

@@ -0,0 +1,67 @@
+package app.websocket.handlers;
+
+import app.annotations.enums.AuthMethod;
+import app.annotations.interfaces.CheckWebAccess;
+import app.services.ExternalServices;
+import app.websocket.BaseWebsocketHandler;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+import org.springframework.web.socket.CloseStatus;
+import org.springframework.web.socket.TextMessage;
+import org.springframework.web.socket.WebSocketSession;
+import org.springframework.web.socket.handler.TextWebSocketHandler;
+
+import java.util.HashMap;
+
+@Component
+public class ExternalServicesHandler extends TextWebSocketHandler implements BaseWebsocketHandler {
+
+    private final Logger logger = LoggerFactory.getLogger(getClass());
+    private ObjectMapper objectMapper = new ObjectMapper();
+
+    private ExternalServices externalServices;
+
+    @Autowired
+    ExternalServicesHandler(ExternalServices externalServices) {
+        this.externalServices = externalServices;
+    }
+
+    @Override
+    public String getPath() {
+        return "services";
+    }
+
+    @Override
+    @CheckWebAccess(auth_method = AuthMethod.SECRET_KEY)
+    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
+        logger.info("Session {} open", session.getId());
+        super.afterConnectionEstablished(session);
+        if (session.isOpen()) {
+            logger.info("Session {} open", session.getId());
+        }
+    }
+
+    @Override
+    @CheckWebAccess(auth_method = AuthMethod.SECRET_KEY)
+    public void handleTextMessage(WebSocketSession session, TextMessage message) {
+        if (!session.isOpen()) return;
+        HashMap<String, Object> payload;
+        try {
+            payload = objectMapper.readValue(message.getPayload(), HashMap.class);
+        } catch (Exception e) {
+            logger.error("Cannot explode payload: {}", e.getMessage());
+            return;
+        }
+        String service_name = (String) payload.get("name");
+        externalServices.update(service_name);
+    }
+
+    @Override
+    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
+        logger.info("Session {} close", session.getId());
+        super.afterConnectionClosed(session, status);
+    }
+}