1 files changed, 142 insertions, 0 deletions
diff --git a/container-core/src/main/java/com/yahoo/container/di/CloudSubscriberFactory.java b/container-core/src/main/java/com/yahoo/container/di/CloudSubscriberFactory.java
new file mode 100644
index 00000000000..065733a719a
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+++ b/container-core/src/main/java/com/yahoo/container/di/CloudSubscriberFactory.java
@@ -0,0 +1,142 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.di;
+
+import com.yahoo.config.ConfigInstance;
+import com.yahoo.config.subscription.ConfigHandle;
+import com.yahoo.config.subscription.ConfigSource;
+import com.yahoo.config.subscription.ConfigSourceSet;
+import com.yahoo.config.subscription.ConfigSubscriber;
+import com.yahoo.container.di.config.Subscriber;
+import com.yahoo.container.di.config.SubscriberFactory;
+import com.yahoo.vespa.config.ConfigKey;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.WeakHashMap;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * @author Tony Vaagenes
+ * @author ollivir
+ */
+public class CloudSubscriberFactory implements SubscriberFactory {
+
+    private static final Logger log = Logger.getLogger(CloudSubscriberFactory.class.getName());
+
+    private final ConfigSource configSource;
+    private final Map<CloudSubscriber, Integer> activeSubscribers = new WeakHashMap<>();
+
+    private Optional<Long> testGeneration = Optional.empty();
+
+    public CloudSubscriberFactory(ConfigSource configSource) {
+        this.configSource = configSource;
+    }
+
+    @Override
+    public Subscriber getSubscriber(Set<? extends ConfigKey<?>> configKeys) {
+        Set<ConfigKey<ConfigInstance>> subscriptionKeys = new HashSet<>();
+        for(ConfigKey<?> key: configKeys) {
+            @SuppressWarnings("unchecked") // ConfigKey is defined as <CONFIGCLASS extends ConfigInstance>
+            ConfigKey<ConfigInstance> invariant = (ConfigKey<ConfigInstance>) key;
+            subscriptionKeys.add(invariant);
+        }
+        CloudSubscriber subscriber = new CloudSubscriber(subscriptionKeys, configSource);
+
+        testGeneration.ifPresent(subscriber.subscriber::reload); // TODO: test specific code, remove
+        activeSubscribers.put(subscriber, 0);
+
+        return subscriber;
+    }
+
+    //TODO: test specific code, remove
+    @Override
+    public void reloadActiveSubscribers(long generation) {
+        testGeneration = Optional.of(generation);
+
+        List<CloudSubscriber> subscribers = new ArrayList<>(activeSubscribers.keySet());
+        subscribers.forEach(s -> s.subscriber.reload(generation));
+    }
+
+    private static class CloudSubscriber implements Subscriber {
+
+        private final ConfigSubscriber subscriber;
+        private final Map<ConfigKey<ConfigInstance>, ConfigHandle<ConfigInstance>> handles = new HashMap<>();
+
+        // if waitNextGeneration has not yet been called, -1 should be returned
+        private long generation = -1L;
+
+        private CloudSubscriber(Set<ConfigKey<ConfigInstance>> keys, ConfigSource configSource) {
+            this.subscriber = new ConfigSubscriber(configSource);
+            keys.forEach(k -> handles.put(k, subscriber.subscribe(k.getConfigClass(), k.getConfigId())));
+        }
+
+        @Override
+        public boolean configChanged() {
+            return handles.values().stream().anyMatch(ConfigHandle::isChanged);
+        }
+
+        @Override
+        public long generation() {
+            return generation;
+        }
+
+        //mapValues returns a view,, so we need to force evaluation of it here to prevent deferred evaluation.
+        @Override
+        public Map<ConfigKey<ConfigInstance>, ConfigInstance> config() {
+            Map<ConfigKey<ConfigInstance>, ConfigInstance> ret = new HashMap<>();
+            handles.forEach((k, v) -> ret.put(k, v.getConfig()));
+            return ret;
+        }
+
+        @Override
+        public long waitNextGeneration(boolean isInitializing) {
+            if (handles.isEmpty())
+                throw new IllegalStateException("No config keys registered");
+
+            // Catch and just log config exceptions due to missing config values for parameters that do
+            // not have a default value. These exceptions occur when the user has removed a component
+            // from services.xml, and the component takes a config that has parameters without a
+            // default value in the def-file. There is a new 'components' config underway, where the
+            // component is removed, so this old config generation will soon be replaced by a new one.
+            boolean gotNextGen = false;
+            int numExceptions = 0;
+            while ( ! gotNextGen) {
+                try {
+                    if (subscriber.nextGeneration(isInitializing))
+                        gotNextGen = true;
+                }
+                catch (IllegalArgumentException e) {
+                    numExceptions++;
+                    log.log(Level.WARNING, "Got exception from the config system (ignore if you just removed a " +
+                                           "component from your application that used the mentioned config) Subscriber info: " +
+                                           subscriber.toString(), e);
+                    if (numExceptions >= 5)
+                        throw new IllegalArgumentException("Failed retrieving the next config generation", e);
+                }
+            }
+
+            generation = subscriber.getGeneration();
+            return generation;
+        }
+
+        @Override
+        public void close() {
+            subscriber.close();
+        }
+
+    }
+
+    public static class Provider implements com.google.inject.Provider<SubscriberFactory> {
+        @Override
+        public SubscriberFactory get() {
+            return new CloudSubscriberFactory(ConfigSourceSet.createDefault());
+        }
+    }
+
+}