Update throttling pattern (#1937)

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* Update README.md

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* Update pom.xml

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* Update BjornGraphicsComponent.java

* Update BjornInputComponent.java

* Update BjornPhysicsComponent.java

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* Delete BjornInputComponent.java

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* Create App.java

* Update App.java

* Update App.java

* Create BjornGraphicsComponent.java

* Create BjornInputComponent.java

* Create BjornPhysicsComponent.java

* Create Component.java

* Create GameObject.java

* Create GraphicsComponent.java

* Create InputComponent.java

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* Create AppTest.java

* Create UpdateTest.java

* Update throttling pattern example

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Co-authored-by: YanchaoMiao <11710204@mail.sustech.edu.cn>

throttling/src/main/java/com/iluwatar/throttling/App.java

@@ -34,11 +34,11 @@ import lombok.extern.slf4j.Slf4j;
  * complete service by users or a particular tenant. This can allow systems to continue to function
  * and meet service level agreements, even when an increase in demand places load on resources.
  * <p>
- * In this example we have ({@link App}) as the initiating point of the service. This is a time
+ * In this example there is a {@link Bartender} serving beer to {@link BarCustomer}s. This is a time
  * based throttling, i.e. only a certain number of calls are allowed per second.
  * </p>
- * ({@link Tenant}) is the Tenant POJO class with which many tenants can be created ({@link
- * B2BService}) is the service which is consumed by the tenants and is throttled.
+ * ({@link BarCustomer}) is the service tenant class having a name and the number of calls allowed.
+ * ({@link Bartender}) is the service which is consumed by the tenants and is throttled.
  */
 @Slf4j
 public class App {
@@ -50,33 +50,35 @@ public class App {
    */
   public static void main(String[] args) {
     var callsCount = new CallsCount();
-    var adidas = new Tenant("Adidas", 5, callsCount);
-    var nike = new Tenant("Nike", 6, callsCount);
+    var human = new BarCustomer("young human", 2, callsCount);
+    var dwarf = new BarCustomer("dwarf soldier", 4, callsCount);
 
     var executorService = Executors.newFixedThreadPool(2);
 
-    executorService.execute(() -> makeServiceCalls(adidas, callsCount));
-    executorService.execute(() -> makeServiceCalls(nike, callsCount));
+    executorService.execute(() -> makeServiceCalls(human, callsCount));
+    executorService.execute(() -> makeServiceCalls(dwarf, callsCount));
 
     executorService.shutdown();
     try {
-      executorService.awaitTermination(10, TimeUnit.SECONDS);
+      if (!executorService.awaitTermination(10, TimeUnit.SECONDS)) {
+        executorService.shutdownNow();
+      }
     } catch (InterruptedException e) {
-      LOGGER.error("Executor Service terminated: {}", e.getMessage());
+      executorService.shutdownNow();
     }
   }
 
   /**
-   * Make calls to the B2BService dummy API.
+   * Make calls to the bartender.
    */
-  private static void makeServiceCalls(Tenant tenant, CallsCount callsCount) {
-    var timer = new ThrottleTimerImpl(10, callsCount);
-    var service = new B2BService(timer, callsCount);
+  private static void makeServiceCalls(BarCustomer barCustomer, CallsCount callsCount) {
+    var timer = new ThrottleTimerImpl(1000, callsCount);
+    var service = new Bartender(timer, callsCount);
     // Sleep is introduced to keep the output in check and easy to view and analyze the results.
-    IntStream.range(0, 20).forEach(i -> {
-      service.dummyCustomerApi(tenant);
+    IntStream.range(0, 50).forEach(i -> {
+      service.orderDrink(barCustomer);
       try {
-        Thread.sleep(1);
+        Thread.sleep(100);
       } catch (InterruptedException e) {
         LOGGER.error("Thread interrupted: {}", e.getMessage());
       }

throttling/src/main/java/com/iluwatar/throttling/BarCustomer.java

@@ -25,22 +25,26 @@ package com.iluwatar.throttling;
 
 import java.security.InvalidParameterException;
 
-/**
- * A Pojo class to create a basic Tenant with the allowed calls per second.
- */
-public class Tenant {
+import lombok.Getter;
 
+/**
+ * BarCustomer is a tenant with a name and a number of allowed calls per second.
+ */
+public class BarCustomer {
+
+  @Getter
   private final String name;
+  @Getter
   private final int allowedCallsPerSecond;
 
   /**
    * Constructor.
    *
-   * @param name                  Name of the tenant
-   * @param allowedCallsPerSecond The number of calls allowed for a particular tenant.
+   * @param name Name of the BarCustomer
+   * @param allowedCallsPerSecond The number of calls allowed for this particular tenant.
    * @throws InvalidParameterException If number of calls is less than 0, throws exception.
    */
-  public Tenant(String name, int allowedCallsPerSecond, CallsCount callsCount) {
+  public BarCustomer(String name, int allowedCallsPerSecond, CallsCount callsCount) {
     if (allowedCallsPerSecond < 0) {
       throw new InvalidParameterException("Number of calls less than 0 not allowed");
     }
@@ -48,12 +52,4 @@ public class Tenant {
     this.allowedCallsPerSecond = allowedCallsPerSecond;
     callsCount.addTenant(name);
   }
-
-  public String getName() {
-    return name;
-  }
-
-  public int getAllowedCallsPerSecond() {
-    return allowedCallsPerSecond;
-  }
 }

throttling/src/main/java/com/iluwatar/throttling/Bartender.java

@@ -29,33 +29,32 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * A service which accepts a tenant and throttles the resource based on the time given to the
- * tenant.
+ * Bartender is a service which accepts a BarCustomer (tenant) and throttles
+ * the resource based on the time given to the tenant.
  */
-class B2BService {
+class Bartender {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(B2BService.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(Bartender.class);
   private final CallsCount callsCount;
 
-  public B2BService(Throttler timer, CallsCount callsCount) {
+  public Bartender(Throttler timer, CallsCount callsCount) {
     this.callsCount = callsCount;
     timer.start();
   }
 
   /**
-   * Calls dummy customer api.
-   *
+   * Orders a drink from the bartender.
    * @return customer id which is randomly generated
    */
-  public int dummyCustomerApi(Tenant tenant) {
-    var tenantName = tenant.getName();
+  public int orderDrink(BarCustomer barCustomer) {
+    var tenantName = barCustomer.getName();
     var count = callsCount.getCount(tenantName);
-    LOGGER.debug("Counter for {} : {} ", tenant.getName(), count);
-    if (count >= tenant.getAllowedCallsPerSecond()) {
-      LOGGER.error("API access per second limit reached for: {}", tenantName);
+    if (count >= barCustomer.getAllowedCallsPerSecond()) {
+      LOGGER.error("I'm sorry {}, you've had enough for today!", tenantName);
       return -1;
     }
     callsCount.incrementCount(tenantName);
+    LOGGER.debug("Serving beer to {} : [{} consumed] ", barCustomer.getName(), count + 1);
     return getRandomCustomerId();
   }
 

throttling/src/main/java/com/iluwatar/throttling/CallsCount.java

@@ -69,7 +69,7 @@ public final class CallsCount {
    * Resets the count of all the tenants in the map.
    */
   public void reset() {
-    LOGGER.debug("Resetting the map.");
     tenantCallsCount.replaceAll((k, v) -> new AtomicLong(0));
+    LOGGER.info("reset counters");
   }
 }

throttling/src/test/java/com/iluwatar/throttling/BarCustomerTest.java

@@ -23,20 +23,21 @@
 
 package com.iluwatar.throttling;
 
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import org.junit.jupiter.api.Test;
 
 import java.security.InvalidParameterException;
-import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 /**
  * TenantTest to test the creation of Tenant with valid parameters.
  */
-public class TenantTest {
+public class BarCustomerTest {
 
   @Test
   void constructorTest() {
     assertThrows(InvalidParameterException.class, () -> {
-      new Tenant("FailTenant", -1, new CallsCount());
+      new BarCustomer("sirBrave", -1, new CallsCount());
     });
   }
 }

throttling/src/test/java/com/iluwatar/throttling/BartenderTest.java

@@ -32,19 +32,18 @@ import org.junit.jupiter.api.Test;
 /**
  * B2BServiceTest class to test the B2BService
  */
-public class B2BServiceTest {
+public class BartenderTest {
 
   private final CallsCount callsCount = new CallsCount();
 
   @Test
   void dummyCustomerApiTest() {
-    var tenant = new Tenant("testTenant", 2, callsCount);
+    var tenant = new BarCustomer("pirate", 2, callsCount);
     // In order to assure that throttling limits will not be reset, we use an empty throttling implementation
-    var timer = (Throttler) () -> {
-    };
-    var service = new B2BService(timer, callsCount);
+    var timer = (Throttler) () -> {};
+    var service = new Bartender(timer, callsCount);
 
-    IntStream.range(0, 5).mapToObj(i -> tenant).forEach(service::dummyCustomerApi);
+    IntStream.range(0, 5).mapToObj(i -> tenant).forEach(service::orderDrink);
     var counter = callsCount.getCount(tenant.getName());
     assertEquals(2, counter, "Counter limit must be reached");
   }