1 files changed, 127 insertions, 0 deletions
diff --git a/standalone-container/src/main/java/com/yahoo/container/standalone/StandaloneSubscriberFactory.java b/standalone-container/src/main/java/com/yahoo/container/standalone/StandaloneSubscriberFactory.java
new file mode 100644
index 00000000000..882bb5709f4
--- /dev/null
+++ b/standalone-container/src/main/java/com/yahoo/container/standalone/StandaloneSubscriberFactory.java
@@ -0,0 +1,127 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.standalone;
+
+import com.yahoo.config.ConfigBuilder;
+import com.yahoo.config.ConfigInstance;
+import com.yahoo.config.subscription.ConfigInterruptedException;
+import com.yahoo.container.di.config.Subscriber;
+import com.yahoo.container.di.config.SubscriberFactory;
+import com.yahoo.vespa.config.ConfigKey;
+import com.yahoo.vespa.model.VespaModel;
+
+import java.lang.reflect.InvocationTargetException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * @author Tony Vaagenes
+ * @author gjoranv
+ * @author ollivir
+ */
+public class StandaloneSubscriberFactory implements SubscriberFactory {
+    private final VespaModel root;
+
+    public StandaloneSubscriberFactory(VespaModel root) {
+        this.root = root;
+    }
+
+    private class StandaloneSubscriber implements Subscriber {
+        private final Set<ConfigKey<ConfigInstance>> configKeys;
+        private long generation = -1L;
+
+        StandaloneSubscriber(Set<ConfigKey<ConfigInstance>> configKeys) {
+            this.configKeys = configKeys;
+        }
+
+        @Override
+        public boolean configChanged() {
+            return generation == 0;
+        }
+
+        @Override
+        public void close() {
+        }
+
+        @Override
+        public Map<ConfigKey<ConfigInstance>, ConfigInstance> config() {
+            Map<ConfigKey<ConfigInstance>, ConfigInstance> ret = new HashMap<>();
+            for (ConfigKey<ConfigInstance> key : configKeys) {
+                ConfigInstance.Builder builder = root.getConfig(newBuilderInstance(key), key.getConfigId());
+                if (builder == null) {
+                    throw new RuntimeException("Invalid config id " + key.getConfigId());
+                }
+                ret.put(key, newConfigInstance(builder));
+            }
+            return ret;
+        }
+
+        @Override
+        public long waitNextGeneration() {
+            generation++;
+
+            if (generation != 0) {
+                try {
+                    while (!Thread.interrupted()) {
+                        Thread.sleep(10000);
+                    }
+                } catch (InterruptedException e) {
+                    throw new ConfigInterruptedException(e);
+                }
+            }
+
+            return generation;
+        }
+
+        // if waitNextGeneration has not yet been called, -1 should be returned
+        @Override
+        public long generation() {
+            return generation;
+        }
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public Subscriber getSubscriber(Set<? extends ConfigKey<?>> configKeys) {
+        return new StandaloneSubscriber((Set<ConfigKey<ConfigInstance>>) configKeys);
+    }
+
+    public void reloadActiveSubscribers(long generation) {
+        throw new RuntimeException("unsupported");
+    }
+
+    private static ConfigInstance.Builder newBuilderInstance(ConfigKey<ConfigInstance> key) {
+        try {
+            return builderClass(key).getDeclaredConstructor().newInstance();
+        } catch (InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
+            throw new RuntimeException("ConfigInstance builder cannot be instantiated", e);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private static Class<ConfigInstance.Builder> builderClass(ConfigKey<ConfigInstance> key) {
+        Class<?> configClass = key.getConfigClass();
+        if (configClass != null) {
+            Class<?>[] nestedClasses = configClass.getClasses();
+            for (Class<?> clazz : nestedClasses) {
+                if (clazz.getName().equals(key.getConfigClass().getName() + "$Builder")) {
+                    return (Class<ConfigInstance.Builder>) clazz;
+                }
+            }
+        }
+        throw new RuntimeException("Builder class for " + (configClass == null ? null : configClass.getName()) + " could not be located");
+    }
+
+    private static ConfigInstance newConfigInstance(ConfigBuilder builder) {
+        try {
+            return configClass(builder).getConstructor(builder.getClass()).newInstance(builder);
+        } catch (InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException e) {
+            throw new RuntimeException("ConfigInstance cannot be instantiated", e);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    private static Class<ConfigInstance> configClass(ConfigBuilder builder) {
+        return (Class<ConfigInstance>) builder.getClass().getEnclosingClass();
+    }
+}