cache the "tree"

src/main/java/com/commafeed/backend/cache/CacheService.java

@@ -6,6 +6,8 @@ import org.apache.commons.codec.digest.DigestUtils;
 
 import com.commafeed.backend.model.Feed;
 import com.commafeed.backend.model.FeedEntry;
+import com.commafeed.backend.model.User;
+import com.commafeed.frontend.model.Category;
 
 public abstract class CacheService {
 
@@ -13,9 +15,15 @@ public abstract class CacheService {
 
 	public abstract void setLastEntries(Feed feed, List<String> entries);
 
-	public String buildKey(Feed feed, FeedEntry entry) {
+	public String buildUniqueEntryKey(Feed feed, FeedEntry entry) {
 		return DigestUtils.sha1Hex(entry.getGuid() +
 				entry.getUrl());
 	}
 
+	public abstract Category getRootCategory(User user);
+
+	public abstract void setRootCategory(User user, Category category);
+
+	public abstract void invalidateRootCategory(User... users);
+
 }

src/main/java/com/commafeed/backend/cache/InMemoryCacheService.java

@@ -1,46 +0,0 @@
-package com.commafeed.backend.cache;
-
-import java.util.Collections;
-import java.util.List;
-import java.util.concurrent.TimeUnit;
-
-import javax.annotation.PostConstruct;
-import javax.enterprise.context.ApplicationScoped;
-import javax.enterprise.inject.Alternative;
-import javax.inject.Inject;
-
-import com.commafeed.backend.model.Feed;
-import com.commafeed.backend.services.ApplicationSettingsService;
-import com.google.common.cache.Cache;
-import com.google.common.cache.CacheBuilder;
-
-@Alternative
-@ApplicationScoped
-public class InMemoryCacheService extends CacheService {
-
-	@Inject
-	ApplicationSettingsService applicationSettingsService;
-
-	private Cache<Long, List<String>> entryCache;
-
-	@PostConstruct
-	private void init() {
-		int capacity = applicationSettingsService.get().isHeavyLoad() ? 1000000 : 100;
-		entryCache = CacheBuilder.newBuilder()
-				.maximumSize(capacity).expireAfterWrite(24, TimeUnit.HOURS).build();
-	}
-
-	@Override
-	public List<String> getLastEntries(Feed feed) {
-		List<String> list = entryCache.getIfPresent(feed.getId());
-		if (list == null) {
-			list = Collections.emptyList();
-		}
-		return list;
-	}
-
-	@Override
-	public void setLastEntries(Feed feed, List<String> entries) {
-		entryCache.put(feed.getId(), entries);
-	}
-}

src/main/java/com/commafeed/backend/cache/NoopCacheService.java

@@ -0,0 +1,40 @@
+package com.commafeed.backend.cache;
+
+import java.util.Collections;
+import java.util.List;
+
+import javax.enterprise.context.ApplicationScoped;
+import javax.enterprise.inject.Alternative;
+
+import com.commafeed.backend.model.Feed;
+import com.commafeed.backend.model.User;
+import com.commafeed.frontend.model.Category;
+
+@Alternative
+@ApplicationScoped
+public class NoopCacheService extends CacheService {
+
+	@Override
+	public List<String> getLastEntries(Feed feed) {
+		return Collections.emptyList();
+	}
+
+	@Override
+	public void setLastEntries(Feed feed, List<String> entries) {
+	}
+
+	@Override
+	public Category getRootCategory(User user) {
+		return null;
+	}
+
+	@Override
+	public void setRootCategory(User user, Category category) {
+
+	}
+
+	@Override
+	public void invalidateRootCategory(User... users) {
+
+	}
+}

src/main/java/com/commafeed/backend/cache/RedisCacheService.java

@@ -7,26 +7,37 @@ import java.util.concurrent.TimeUnit;
 import javax.enterprise.context.ApplicationScoped;
 import javax.enterprise.inject.Alternative;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import redis.clients.jedis.Jedis;
 import redis.clients.jedis.JedisPool;
 import redis.clients.jedis.JedisPoolConfig;
 import redis.clients.jedis.Pipeline;
 
 import com.commafeed.backend.model.Feed;
+import com.commafeed.backend.model.Models;
+import com.commafeed.backend.model.User;
+import com.commafeed.frontend.model.Category;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.api.client.util.Lists;
 
 @Alternative
 @ApplicationScoped
 public class RedisCacheService extends CacheService {
 
+	private static final Logger log = LoggerFactory.getLogger(RedisCacheService.class);
+
 	private JedisPool pool = new JedisPool(new JedisPoolConfig(), "localhost");
+	private ObjectMapper mapper = new ObjectMapper();
 
 	@Override
 	public List<String> getLastEntries(Feed feed) {
 		List<String> list = Lists.newArrayList();
 		Jedis jedis = pool.getResource();
 		try {
-			String key = buildKey(feed);
+			String key = buildRedisEntryKey(feed);
 			Set<String> members = jedis.smembers(key);
 			for (String member : members) {
 				list.add(member);
@@ -41,7 +52,7 @@ public class RedisCacheService extends CacheService {
 	public void setLastEntries(Feed feed, List<String> entries) {
 		Jedis jedis = pool.getResource();
 		try {
-			String key = buildKey(feed);
+			String key = buildRedisEntryKey(feed);
 
 			Pipeline pipe = jedis.pipelined();
 			pipe.del(key);
@@ -55,7 +66,64 @@ public class RedisCacheService extends CacheService {
 		}
 	}
 
-	private String buildKey(Feed feed) {
+	@Override
+	public Category getRootCategory(User user) {
+		Category cat = null;
+		Jedis jedis = pool.getResource();
+		try {
+			String key = buildRedisRootCategoryKey(user);
+			String json = jedis.get(key);
+			if (json != null) {
+				cat = mapper.readValue(json, Category.class);
+			}
+		} catch (Exception e) {
+			log.error(e.getMessage(), e);
+		} finally {
+			pool.returnResource(jedis);
+		}
+		return cat;
+	}
+
+	@Override
+	public void setRootCategory(User user, Category category) {
+		Jedis jedis = pool.getResource();
+		try {
+			String key = buildRedisRootCategoryKey(user);
+
+			Pipeline pipe = jedis.pipelined();
+			pipe.del(key);
+			pipe.set(key, mapper.writeValueAsString(category));
+			pipe.expire(key, (int) TimeUnit.MINUTES.toSeconds(30));
+			pipe.sync();
+		} catch (JsonProcessingException e) {
+			log.error(e.getMessage(), e);
+		} finally {
+			pool.returnResource(jedis);
+		}
+	}
+
+	@Override
+	public void invalidateRootCategory(User... users) {
+		Jedis jedis = pool.getResource();
+		try {
+			Pipeline pipe = jedis.pipelined();
+			if (users != null) {
+				for (User user : users) {
+					String key = buildRedisRootCategoryKey(user);
+					pipe.del(key);
+				}
+			}
+			pipe.sync();
+		} finally {
+			pool.returnResource(jedis);
+		}
+	}
+
+	private String buildRedisRootCategoryKey(User user) {
+		return "root_cat:" + Models.getId(user);
+	}
+
+	private String buildRedisEntryKey(Feed feed) {
 		return "feed:" + feed.getId();
 	}