1 files changed, 90 insertions, 0 deletions
diff --git a/application/src/main/java/com/yahoo/application/container/ProcessingBase.java b/application/src/main/java/com/yahoo/application/container/ProcessingBase.java
new file mode 100644
index 00000000000..6637669874d
--- /dev/null
+++ b/application/src/main/java/com/yahoo/application/container/ProcessingBase.java
@@ -0,0 +1,90 @@
+// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.application.container;
+
+import com.google.common.annotations.Beta;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.yahoo.component.ComponentSpecification;
+import com.yahoo.component.chain.Chain;
+import com.yahoo.processing.Processor;
+import com.yahoo.processing.Request;
+import com.yahoo.processing.Response;
+import com.yahoo.processing.execution.chain.ChainRegistry;
+import com.yahoo.processing.rendering.AsynchronousRenderer;
+import com.yahoo.processing.rendering.Renderer;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+
+/**
+ * @author gjoranv
+ * @since 5.1.15
+ */
+@Beta
+public abstract class ProcessingBase<
+        REQUEST extends Request,
+        RESPONSE extends Response,
+        PROCESSOR extends Processor>
+{
+    /**
+     * Returns a registry of configured chains.
+     *
+     * @return a registry of configured chains
+     */
+    public abstract ChainRegistry<PROCESSOR> getChains();
+
+    /**
+     * Processes the given request with the given chain, and returns the response.
+     *
+     * @param chain the specification of the chain to execute
+     * @param request the request to process
+     * @return a response
+     */
+    public final RESPONSE process(ComponentSpecification chain, REQUEST request) {
+        Chain<PROCESSOR> processingChain = getChain(chain);
+        return doProcess(processingChain, request);
+    }
+
+    protected abstract RESPONSE doProcess(Chain<PROCESSOR> chain, REQUEST request);
+
+    public final byte[] processAndRender(ComponentSpecification chainSpec,
+                                         ComponentSpecification rendererSpec,
+                                         REQUEST request) throws IOException {
+        ByteArrayOutputStream stream = new ByteArrayOutputStream();
+        Renderer<RESPONSE> renderer = getRenderer(rendererSpec);
+        ListenableFuture<Boolean> renderTask = doProcessAndRender(chainSpec, request, renderer, stream);
+
+        awaitFuture(renderTask);
+        return stream.toByteArray();
+    }
+
+    private void awaitFuture(ListenableFuture<Boolean> renderTask) {
+        try {
+            renderTask.get();
+        } catch (InterruptedException | ExecutionException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    protected abstract ListenableFuture<Boolean> doProcessAndRender(ComponentSpecification chainSpec,
+                                                                    REQUEST request,
+                                                                    Renderer<RESPONSE> renderer,
+                                                                    ByteArrayOutputStream stream) throws IOException ;
+
+    protected Chain<PROCESSOR> getChain(ComponentSpecification chainSpec) {
+        Chain<PROCESSOR> chain = getChains().getComponent(chainSpec);
+        if (chain == null) {
+            throw new IllegalArgumentException("No such chain: " + chainSpec);
+        }
+        return chain;
+    }
+
+    protected final Renderer<RESPONSE> getRenderer(ComponentSpecification spec) {
+        return doGetRenderer(spec);
+    }
+
+    // TODO: This would not be necessary if Search/ProcHandler implemented a common interface
+    protected abstract Renderer<RESPONSE> doGetRenderer(ComponentSpecification spec);
+
+}