Currently, SADIS caches Subscriber records defining Subscriber Tagging requirements, authentication data and other service flow information. The OF Flow Table ID used to reference a Technology Profile for a given Subscriber needs to be able to be added to the Subscriber Record and a Reference to an Upstream and Downstream OF Meter also supported.

Change-Id: I2951d777e557c5354eb7ef0d9d8645c22b763740
diff --git a/app/src/main/java/org/opencord/sadis/impl/InformationAdapter.java b/app/src/main/java/org/opencord/sadis/impl/InformationAdapter.java
new file mode 100644
index 0000000..5314b73
--- /dev/null
+++ b/app/src/main/java/org/opencord/sadis/impl/InformationAdapter.java
@@ -0,0 +1,228 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.opencord.sadis.impl;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
+import com.google.common.collect.Maps;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.net.config.ConfigFactory;
+import org.onosproject.net.config.NetworkConfigRegistry;
+import org.opencord.sadis.BaseInformation;
+import org.opencord.sadis.BaseConfig;
+import org.opencord.sadis.BaseInformationService;
+import java.util.Set;
+
+
+public abstract class InformationAdapter<T extends BaseInformation, K extends BaseConfig<T>>
+        implements BaseInformationService<T> {
+
+    private final Logger log = LoggerFactory.getLogger(this.getClass());
+
+    protected static final int DEFAULT_MAXIMUM_CACHE_SIZE = 0;
+    protected static final long DEFAULT_TTL = 0;
+    protected String url;
+    protected ObjectMapper mapper;
+    protected Cache<String, T> cache;
+    protected int maxiumCacheSize = DEFAULT_MAXIMUM_CACHE_SIZE;
+    protected long cacheEntryTtl = DEFAULT_TTL;
+
+    protected Map<String, T> localCfgData = null;
+
+    public final void updateConfig(NetworkConfigRegistry cfgService) {
+        K cfg = getConfig(cfgService);
+        if (cfg == null) {
+            this.log.warn("Configuration not available");
+            return;
+        }
+        this.log.info("Cache Max Size: {}", cfg.getCacheMaxSize());
+        this.log.info("Cache TTL:      {}", cfg.getCacheTtl().getSeconds());
+        this.log.info("Entries:        {}", cfg.getEntries());
+
+        configure(cfg);
+    }
+
+    public K getConfig(NetworkConfigRegistry cfgService) {
+        return cfgService.getConfig(getAppId(), getConfigClass());
+    }
+
+    /**
+     * Configures the Adapter for data source and cache parameters.
+     *
+     * @param cfg Configuration data.
+     */
+    public void configure(K cfg) {
+
+        String url = null;
+        try {
+            // if the url is not present then assume data is in netcfg
+            if (cfg.getUrl() != null) {
+                url = cfg.getUrl().toString();
+            } else {
+                localCfgData = Maps.newConcurrentMap();
+
+                cfg.getEntries().forEach(entry ->
+                        localCfgData.put(entry.id(), entry));
+                log.info("url is null, data source is local netcfg data");
+            }
+        } catch (MalformedURLException mUrlEx) {
+            log.error("Invalid URL specified: {}", mUrlEx);
+        }
+
+        int maximumCacheSeize = cfg.getCacheMaxSize();
+        long cacheEntryTtl = cfg.getCacheTtl().getSeconds();
+
+        // Rebuild cache if needed
+        if (isUrlChanged(url) || maximumCacheSeize != this.maxiumCacheSize ||
+                cacheEntryTtl != this.cacheEntryTtl) {
+            this.maxiumCacheSize = maximumCacheSeize;
+            this.cacheEntryTtl = cacheEntryTtl;
+            this.url = url;
+
+            Cache<String, T> newCache = CacheBuilder.newBuilder()
+                    .maximumSize(maxiumCacheSize).expireAfterAccess(cacheEntryTtl, TimeUnit.SECONDS).build();
+            Cache<String, T> oldCache = cache;
+
+            synchronized (this) {
+                cache = newCache;
+            }
+
+            oldCache.invalidateAll();
+            oldCache.cleanUp();
+        }
+    }
+
+    protected boolean isUrlChanged(String url) {
+        if (url == null && this.url == null) {
+            return false;
+        }
+        return !((url == this.url) || (url != null && url.equals(this.url)));
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.opencord.sadis.SadisService#clearCache()
+     */
+    @Override
+    public void invalidateAll() {
+        cache.invalidateAll();
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.opencord.sadis.BaseInformationService#invalidateId()
+     */
+    @Override
+    public void invalidateId(String id) {
+        cache.invalidate(id);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.opencord.sadis.BaseInformationService#getfromCache(java.lang.
+     * String)
+     */
+    @Override
+    public T getfromCache(String id) {
+        Cache<String, T> local;
+        synchronized (this) {
+            local = cache;
+        }
+        T info = local.getIfPresent(id);
+        if (info != null) {
+            return info;
+        }
+        return null;
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.opencord.sadis.BaseInformationService#get(java.lang.
+     * String)
+     */
+    @Override
+    public T get(String id) {
+        Cache<String, T> local;
+        synchronized (this) {
+            local = cache;
+        }
+
+        T info = local.getIfPresent(id);
+        if (info != null) {
+            return info;
+        }
+
+        /*
+         * Not in cache, if we have a URL configured we can attempt to get it
+         * from there, else check for it in the locally configured data
+         */
+        if (this.url == null) {
+            info = (localCfgData == null) ? null : localCfgData.get(id);
+
+            if (info != null) {
+                local.put(id, info);
+                return info;
+            }
+        } else {
+            // Augment URL with query parameters
+            String urlWithSubId = this.url.replaceAll("%s", id);
+            log.info("Getting data from the remote URL {}", urlWithSubId);
+
+            try (InputStream io = new URL(urlWithSubId).openStream()) {
+                info = mapper.readValue(io, getInformationClass());
+                local.put(id, info);
+                return info;
+            } catch (IOException e) {
+                // TODO use a better http library that allows us to read status code
+                log.debug("Exception while reading remote data {} ", e.getMessage());
+            }
+        }
+        log.debug("Data not found for id {}", id);
+        return null;
+    }
+
+    public abstract void registerModule();
+
+    public abstract Set<ConfigFactory> getConfigFactories();
+
+    public abstract JsonCodec<T> getCodec();
+
+    public abstract Class<T> getInformationClass();
+
+    public abstract Class<K> getConfigClass();
+
+    public abstract ApplicationId getAppId();
+}