extract Servlet functionality into sse-common module for reuse

pom.xml

@@ -8,9 +8,10 @@
     <version>2.10</version> <!-- CAUTION: do not go past 2.16 without doing something like https://github.com/jenkinsci/workflow-cps-plugin/pull/87 -->
     <relativePath />
   </parent>
-  <artifactId>sse-gateway</artifactId>
+
+  <artifactId>sse-gateway-parent</artifactId>
   <version>1.16-SNAPSHOT</version>
-  <packaging>hpi</packaging>
+  <packaging>pom</packaging>
 
   <properties>
     <jenkins.version>2.2</jenkins.version>
@@ -51,49 +52,37 @@
     </pluginRepository>
   </pluginRepositories>
 
-  <dependencies>
-    <dependency>
-      <groupId>javax.servlet</groupId>
-      <artifactId>javax.servlet-api</artifactId>
-      <version>3.1.0</version>
-      <scope>provided</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.jenkins-ci.plugins</groupId>
-      <artifactId>pubsub-light</artifactId>
-      <version>1.6</version>
-    </dependency>
-
-    <!-- Test deps -->
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <version>1.10.19</version>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>com.github.eirslett</groupId>
-      <artifactId>frontend-plugin-core</artifactId>
-      <version>1.0</version>
-      <scope>test</scope>
-    </dependency>
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>javax.servlet</groupId>
+        <artifactId>javax.servlet-api</artifactId>
+        <version>3.1.0</version>
+        <scope>provided</scope>
+      </dependency>
+      <dependency>
+        <groupId>org.jenkins-ci.plugins</groupId>
+        <artifactId>pubsub-light</artifactId>
+        <version>1.6</version>
+      </dependency>
 
-  </dependencies>
+      <!-- Test deps -->
+      <dependency>
+        <groupId>org.mockito</groupId>
+        <artifactId>mockito-core</artifactId>
+        <version>1.10.19</version>
+      </dependency>
+      <dependency>
+        <groupId>com.github.eirslett</groupId>
+        <artifactId>frontend-plugin-core</artifactId>
+        <version>1.0</version>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
 
-  <build>
-    <plugins>
-        <plugin>
-          <groupId>org.jenkins-ci.tools</groupId>
-          <artifactId>maven-hpi-plugin</artifactId>
-          <extensions>true</extensions>
-          <configuration>
-            <showDeprecation>true</showDeprecation>
-            <contextPath>/jenkins</contextPath>
-            <!-- TODO specify ${java.level} when JENKINS-20679 implemented -->
-            <disabledTestInjection>true</disabledTestInjection>
-          </configuration>
-        </plugin>
-    </plugins>
-  </build>
-
+  <modules>
+    <module>sse-common</module>
+    <module>sse-gateway-client</module>
+    <module>sse-gateway</module>
+  </modules>
 </project>

sse-common/pom.xml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.jenkins-ci.plugins</groupId>
+        <artifactId>sse-gateway-parent</artifactId>
+        <version>1.16-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>sse-common</artifactId>
+    <version>1.16-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+    <dependencies>
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.jenkins-ci.plugins</groupId>
+            <artifactId>pubsub-light</artifactId>
+        </dependency>
+
+        <!-- Test deps -->
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

sse-common/src/main/java/org/jenkinsci/plugins/ssegateway/SseServletBase.java

@@ -0,0 +1,91 @@
+package org.jenkinsci.plugins.ssegateway;
+
+import org.jenkinsci.plugins.ssegateway.sse.EventDispatcher;
+import org.jenkinsci.plugins.ssegateway.sse.EventDispatcherFactory;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpSession;
+import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * SSE base functionality for web applications based on Servlet API.
+ */
+public class SseServletBase {
+    private static final Logger LOGGER = Logger.getLogger(SseServletBase.class.getName());
+
+    /**
+     * Re-initialize or create a {@link EventDispatcher} for the clientId associated with this request.
+     *
+     * @throws IOException
+     */
+    public void initDispatcher(HttpServletRequest request, HttpServletResponse response) throws IOException {
+        String clientId = request.getParameter("clientId");
+
+        if (clientId == null) {
+            throw new IOException("No 'clientId' parameter specified in connect request.");
+        }
+
+        HttpSession session = request.getSession();
+        EventDispatcher dispatcher = EventDispatcherFactory.getDispatcher(clientId, session);
+
+        // If there was already a dispatcher with this ID, then remove
+        // all subscriptions from it and reuse the instance.
+        if (dispatcher != null) {
+            LOGGER.log(Level.FINE, "We already have a Dispatcher for clientId {0}. Removing all subscriptions on the existing Dispatcher instance and reusing it.", dispatcher.toString());
+            dispatcher.unsubscribeAll();
+        } else {
+            // Else create a new instance with this id.
+            EventDispatcherFactory.newDispatcher(clientId, session);
+        }
+
+        response.setStatus(HttpServletResponse.SC_OK);
+    }
+
+    /**
+     * Returns true if the given {@link SubscriptionConfigQueue.SubscriptionConfig} is ready to be enqueued.
+     *
+     * @throws IOException
+     */
+    public boolean validateSubscriptionConfig(SubscriptionConfigQueue.SubscriptionConfig subscriptionConfig) throws IOException {
+        LOGGER.log(Level.FINE, "Processing configuration request. batchId={0}", subscriptionConfig.getBatchId());
+        return subscriptionConfig.getDispatcherId() != null && subscriptionConfig.hasConfigs();
+    }
+
+    /**
+     * Returns true if the given {@link SubscriptionConfigQueue.SubscriptionConfig} is successfully enqueued.
+     *
+     * @throws IOException
+     */
+    public boolean enqueueSubscriptionConfig(SubscriptionConfigQueue.SubscriptionConfig subscriptionConfig) throws IOException {
+        // The requests are added to a queue and processed async. A
+        // status notification will be pushed to the client async.
+        return SubscriptionConfigQueue.add(subscriptionConfig);
+    }
+
+    /**
+     * Returns true if the dispatcherId associated with this request exists and a ping event is successfully dispatched to it.
+     *
+     * @throws IOException
+     */
+    public boolean ping(HttpServletRequest request) throws IOException {
+        String dispatcherId = request.getParameter("dispatcherId");
+
+        if (dispatcherId != null) {
+            EventDispatcher dispatcher = EventDispatcherFactory.getDispatcher(dispatcherId, request.getSession());
+            if (dispatcher != null) {
+                try {
+                    dispatcher.dispatchEvent("pingback", "ack");
+                } catch (ServletException e) {
+                    LOGGER.log(Level.FINE, "Failed to send pingback to dispatcher " + dispatcherId + ".", e);
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+}

src/main/java/org/jenkinsci/plugins/ssegateway/SubscriptionConfigQueue.java → sse-common/src/main/java/org/jenkinsci/plugins/ssegateway/SubscriptionConfigQueue.java

@@ -31,8 +31,8 @@
 import org.jenkinsci.plugins.ssegateway.sse.EventDispatcherFactory;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
-import org.kohsuke.stapler.StaplerRequest;
 
+import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpSession;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -171,7 +171,7 @@ String getDispatcherId() {
             return dispatcherId;
         }
 
-        static SubscriptionConfig fromRequest(StaplerRequest request) throws IOException {
+        static SubscriptionConfig fromRequest(HttpServletRequest request) throws IOException {
             JSONObject payload = Util.readJSONPayload(request);
             SubscriptionConfig config = new SubscriptionConfig();
 

src/main/java/org/jenkinsci/plugins/ssegateway/Util.java → sse-common/src/main/java/org/jenkinsci/plugins/ssegateway/Util.java

@@ -28,8 +28,8 @@
 import org.apache.commons.io.IOUtils;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.NoExternalUse;
-import org.kohsuke.stapler.StaplerRequest;
 
+import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpSession;
 import java.io.File;
 import java.io.IOException;
@@ -48,7 +48,7 @@ public class Util {
     private Util() {
     }
 
-    public static JSONObject readJSONPayload(StaplerRequest request) throws IOException {
+    public static JSONObject readJSONPayload(HttpServletRequest request) throws IOException {
         String characterEncoding = request.getCharacterEncoding();
 
         if (characterEncoding == null) {