Add timeout handler (#17)

Author: Katsute

src/main/java/dev/katsute/simplehttpserver/SimpleHttpHandler.java

@@ -37,6 +37,7 @@
  * @see dev.katsute.simplehttpserver.handler.RootHandler
  * @see dev.katsute.simplehttpserver.handler.SSEHandler
  * @see dev.katsute.simplehttpserver.handler.TemporaryHandler
+ * @see dev.katsute.simplehttpserver.handler.TimeoutHandler
  * @see dev.katsute.simplehttpserver.handler.throttler.ThrottledHandler
  * @see dev.katsute.simplehttpserver.handler.file.FileHandler
  * @since 5.0.0

src/main/java/dev/katsute/simplehttpserver/handler/TimeoutHandler.java

@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2022 Katsute <https://github.com/Katsute>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+package dev.katsute.simplehttpserver.handler;
+
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpHandler;
+import dev.katsute.simplehttpserver.SimpleHttpExchange;
+import dev.katsute.simplehttpserver.SimpleHttpHandler;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.util.Objects;
+import java.util.concurrent.*;
+
+/**
+ * The timeout handler runs a handler and times out after a set time.
+ *
+ * @since 5.0.0
+ * @version 5.0.0
+ * @author Katsute
+ */
+public class TimeoutHandler implements SimpleHttpHandler {
+
+    private final HttpHandler handler;
+
+    private final TimeUnit unit;
+    private final long timeout;
+
+    private final ExecutorService service = Executors.newCachedThreadPool();
+
+    /**
+     * Creates a timeout handler.
+     *
+     * @param handler handler
+     * @param timeout how long until timeout in seconds
+     *
+     * @since 5.0.0
+     */
+    public TimeoutHandler(final HttpHandler handler, final double timeout){
+        this(handler, timeout, TimeUnit.SECONDS);
+    }
+
+    /**
+     * Creates a timeout handler.
+     *
+     * @param handler handler
+     * @param timeout how long until timeout
+     * @param unit timeout units
+     *
+     * @see TimeUnit
+     * @since 5.0.0
+     */
+    public TimeoutHandler(final HttpHandler handler, final double timeout, final TimeUnit unit){
+        this.handler = Objects.requireNonNull(handler);
+        this.timeout = (long) timeout;
+        this.unit = Objects.requireNonNull(unit);
+    }
+
+    @Override
+    public final void handle(final HttpExchange exchange) throws IOException{
+        SimpleHttpHandler.super.handle(exchange);
+    }
+
+    @Override
+    public final void handle(final SimpleHttpExchange exchange) throws IOException{
+        final Future<?> future = service.submit(() -> {
+            try{
+                handler.handle(exchange);
+            }catch(final IOException e){
+                throw new RuntimeException(e);
+            }
+        });
+        try{
+            future.get(timeout, unit);
+        }catch(final Throwable e){
+            future.cancel(true);
+            exchange.send(HttpURLConnection.HTTP_CLIENT_TIMEOUT);
+            if(!(e instanceof TimeoutException))
+                throw new RuntimeException(e);
+        }finally{
+            exchange.close();
+        }
+    }
+
+    @Override
+    public String toString(){
+        return "TimeoutHandler{" +
+               "handler=" + handler +
+               ", timeout=" + timeout +
+               ", unit=" + unit +
+               '}';
+    }
+
+}

src/main/java9/module-info.java

@@ -39,6 +39,7 @@
  *     <li>{@link dev.katsute.simplehttpserver.handler.RootHandler}</li>
  *     <li>{@link dev.katsute.simplehttpserver.handler.SSEHandler}</li>
  *     <li>{@link dev.katsute.simplehttpserver.handler.TemporaryHandler}</li>
+ *     <li>{@link dev.katsute.simplehttpserver.handler.TimeoutHandler}</li>
  *     <li>
  *         {@link dev.katsute.simplehttpserver.handler.file.FileHandler}
  *         <ul>

src/test/java/dev/katsute/simplehttpserver/handler/TimeoutTests.java

@@ -0,0 +1,88 @@
+package dev.katsute.simplehttpserver.handler;
+
+import dev.katsute.simplehttpserver.*;
+import org.junit.jupiter.api.*;
+
+import java.io.IOException;
+import java.time.Duration;
+import java.time.temporal.ChronoUnit;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+final class TimeoutTests {
+
+    private static SimpleHttpServer server;
+
+    @BeforeAll
+    static void beforeAll() throws IOException{
+        server = SimpleHttpServer.create(8080);
+        server.start();
+    }
+
+    @AfterAll
+    static void afterAll(){
+        server.stop();
+    }
+
+    @Test
+    final void testTimeout(){
+        server.createContext("timeout/timeout", new TimeoutHandler(
+            (SimpleHttpHandler) exchange -> {
+                try{
+                    Thread.sleep(4000);
+                    exchange.send(200);
+                }catch(InterruptedException ignored){}
+            },
+            2,
+            TimeUnit.SECONDS
+        ));
+
+        final AtomicInteger code = new AtomicInteger();
+
+        Assertions.assertTimeout(
+            Duration.of(3, ChronoUnit.SECONDS),
+            () -> code.set(Requests.getCode("http://localhost:8080/timeout/timeout"))
+        );
+
+        Assertions.assertEquals(408, code.get());
+    }
+
+    @Test
+    final void testTimeoutSeconds(){
+        server.createContext("timeout/nou", new TimeoutHandler(
+            (SimpleHttpHandler) exchange -> {
+                try{
+                    Thread.sleep(4000);
+                    exchange.send(200);
+                }catch(InterruptedException ignored){}
+            },
+            2
+        ));
+
+        final AtomicInteger code = new AtomicInteger();
+
+        Assertions.assertTimeout(
+            Duration.of(3, ChronoUnit.SECONDS),
+            () -> code.set(Requests.getCode("http://localhost:8080/timeout/nou"))
+        );
+
+        Assertions.assertEquals(408, code.get());
+    }
+
+    @Test
+    final void testTimeoutPass(){
+        server.createContext("timeout/pass", new TimeoutHandler(
+            (SimpleHttpHandler) exchange -> {
+                try{
+                    Thread.sleep(4000);
+                    exchange.send(200);
+                }catch(InterruptedException ignored){}
+            },
+            5,
+            TimeUnit.SECONDS
+        ));
+
+        Assertions.assertEquals(200, Requests.getCode("http://localhost:8080/timeout/pass"));
+    }
+
+}