Add mechanism to restrict the number of requests

Flirt4Free is finnicky with the amount of requests you can do. So we use
a mechanism to only allow 2 requests at a time and a cooldown of 500 ms
between requests.

common/src/main/java/ctbrec/sites/flirt4free/Flirt4FreeModel.java

@@ -8,6 +8,8 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -53,10 +55,19 @@ public class Flirt4FreeModel extends AbstractModel {
     private String userIdt = "";
     private String userIp = "0.0.0.0";
 
+    private static Semaphore requestThrottle = new Semaphore(2, true);
+    private static volatile long lastRequest = 0;
+    private long lastOnlineRequest = 0;
+
+
     @Override
     public boolean isOnline(boolean ignoreCache) throws IOException, ExecutionException, InterruptedException {
-        if(ignoreCache) {
+        long now = System.currentTimeMillis();
+        long timeSinceLastCheck = now - lastOnlineRequest;
+        if (ignoreCache && timeSinceLastCheck > TimeUnit.MINUTES.toMillis(1)) {
             String url = "https://ws.vs3.com/rooms/check-model-status.php?model_name=" + getName();
+            acquireSlot();
+            try {
                 Request request = new Request.Builder()
                         .url(url)
                         .header("Accept", "*/*")
@@ -72,9 +83,9 @@ public class Flirt4FreeModel extends AbstractModel {
                             return false;
                         }
                         JSONObject json = new JSONObject(body);
-                    //LOG.debug("check model status: ", json.toString(2));
+                        // LOG.debug("check model status: {}", json.toString(2));
                         online = Objects.equals(json.optString("status"), "online");
-                    id = json.getString("model_id");
+                        id = String.valueOf(json.get("model_id"));
                         if (online) {
                             try {
                                 loadStreamUrl();
@@ -87,11 +98,15 @@ public class Flirt4FreeModel extends AbstractModel {
                         throw new HttpException(response.code(), response.message());
                     }
                 }
+            } finally {
+                lastOnlineRequest = System.currentTimeMillis();
+                releaseSlot();
+            }
         }
         return online;
     }
 
-    private void loadModelInfo() throws IOException {
+    private void loadModelInfo() throws IOException, InterruptedException {
         String url = getSite().getBaseUrl() + "/webservices/chat-room-interface.php?a=login_room&model_id=" + id;
         LOG.trace("Loading url {}", url);
         Request request = new Request.Builder()
@@ -138,7 +153,12 @@ public class Flirt4FreeModel extends AbstractModel {
         MasterPlaylist masterPlaylist = null;
         try {
             if (withWebsocket) {
+                acquireSlot();
+                try {
                     loadStreamUrl();
+                } finally {
+                    releaseSlot();
+                }
             }
             masterPlaylist = getMasterPlaylist();
         } catch (InterruptedException e) {
@@ -168,6 +188,7 @@ public class Flirt4FreeModel extends AbstractModel {
                 .header("User-Agent", Config.getInstance().getSettings().httpUserAgent)
                 .header("X-Requested-With", "XMLHttpRequest")
                 .build();
+        acquireSlot();
         try (Response response = getSite().getHttpClient().execute(req)) {
             if (response.isSuccessful()) {
                 InputStream inputStream = response.body().byteStream();
@@ -178,6 +199,8 @@ public class Flirt4FreeModel extends AbstractModel {
             } else {
                 throw new HttpException(response.code(), response.message());
             }
+        } finally {
+            releaseSlot();
         }
     }
 
@@ -246,6 +269,7 @@ public class Flirt4FreeModel extends AbstractModel {
                 }
             }
         });
+
         synchronized (monitor) {
             monitor.wait(10_000);
             if (streamHost == null) {
@@ -262,16 +286,20 @@ public class Flirt4FreeModel extends AbstractModel {
 
     @Override
     public void receiveTip(Double tokens) throws IOException {
+        try {
             //        if(tokens < 50 || tokens > 750000) {
             //            throw new RuntimeException("Tip amount has to be between 50 and 750000");
             //        }
 
             // make sure we are logged in and all necessary model data is available
             getSite().login();
+            acquireSlot();
             try {
                 loadStreamUrl();
             } catch (InterruptedException e) {
                 throw new IOException("Couldn't send tip", e);
+            } finally {
+                releaseSlot();
             }
 
             // send the tip
@@ -312,10 +340,15 @@ public class Flirt4FreeModel extends AbstractModel {
                     throw new HttpException(response.code(), response.message());
                 }
             }
+        } catch (InterruptedException e) {
+            throw new IOException("Couldn't acquire request slot", e);
+        }
     }
 
-    private String getUserIdt() throws IOException {
+    private String getUserIdt() throws IOException, InterruptedException {
         if (userIdt.isEmpty()) {
+            acquireSlot();
+            try {
                 Request req = new Request.Builder()
                         .url(getUrl())
                         .header("Accept", "*/*")
@@ -336,6 +369,9 @@ public class Flirt4FreeModel extends AbstractModel {
                         throw new HttpException(response.code(), response.message());
                     }
                 }
+            } finally {
+                releaseSlot();
+            }
         }
         return userIdt;
     }
@@ -361,22 +397,31 @@ public class Flirt4FreeModel extends AbstractModel {
 
     @Override
     public boolean follow() throws IOException {
+        try {
             return changeFavoriteStatus(true);
+        } catch (InterruptedException e) {
+            throw new IOException("Couldn't change follow status for model " + getName(), e);
+        }
     }
 
     @Override
     public boolean unfollow() throws IOException {
         try {
             isOnline(true);
-        } catch (ExecutionException | InterruptedException e) {
-            throw new IOException("Couldn't rectrieve model id", e);
-        }
             return changeFavoriteStatus(false);
+        } catch (ExecutionException | InterruptedException e) {
+            throw new IOException("Couldn't change follow status for model " + getName(), e);
+        }
     }
 
-    private boolean changeFavoriteStatus(boolean add) throws IOException {
+    private boolean changeFavoriteStatus(boolean add) throws IOException, InterruptedException {
         getSite().login();
+        acquireSlot();
+        try {
             loadModelInfo();
+        } finally {
+            releaseSlot();
+        }
         String url = getSite().getBaseUrl() + "/external.php?a=" +
                 (add ? "add_favorite" : "delete_favorite") +
                 "&id=" + id +
@@ -423,4 +468,21 @@ public class Flirt4FreeModel extends AbstractModel {
     public void setOnline(boolean b) {
         online = b;
     }
+
+    private void acquireSlot() throws InterruptedException {
+        LOG.debug("Acquire: {}", requestThrottle.availablePermits());
+        requestThrottle.acquire();
+        long now = System.currentTimeMillis();
+        long millisSinceLastRequest = now - lastRequest;
+        if(millisSinceLastRequest < 500) {
+            LOG.debug("Sleeping: {}", (500-millisSinceLastRequest));
+            Thread.sleep(500 - millisSinceLastRequest);
+        }
+    }
+
+    private void releaseSlot() {
+        lastRequest = System.currentTimeMillis();
+        requestThrottle.release();
+        LOG.debug("Release: {}", requestThrottle.availablePermits());
+    }
 }