Honor expireAfterWrite in the H2CacheImpl

The H2CacheImpl didn't honor the expireAfterWrite. This had an effect
that persisted entries never expired. For example, the web_sessions
cache entries didn't expire after their maxAge was reached.

Change-Id: I3a7c754ee05fe9ac92d96652db4b862bb597eba1
Signed-off-by: Saša Živkov <sasa.zivkov@sap.com>
Signed-off-by: Adrian Görler <adrian.goerler@sap.com>

gerrit-cache-h2/src/main/java/com/google/gerrit/server/cache/h2/H2CacheFactory.java

@@ -161,7 +161,8 @@ class H2CacheFactory implements PersistentCacheFactory, LifecycleListener {
       return defaultFactory.build(def);
     }
 
-    SqlStore<K, V> store = newSqlStore(def.name(), def.keyType(), limit);
+    SqlStore<K, V> store = newSqlStore(def.name(), def.keyType(), limit,
+        def.expireAfterWrite(TimeUnit.SECONDS));
     H2CacheImpl<K, V> cache = new H2CacheImpl<K, V>(
         executor, store, def.keyType(),
         (Cache<K, ValueHolder<V>>) defaultFactory.create(def, true).build());
@@ -182,7 +183,8 @@ class H2CacheFactory implements PersistentCacheFactory, LifecycleListener {
       return defaultFactory.build(def, loader);
     }
 
-    SqlStore<K, V> store = newSqlStore(def.name(), def.keyType(), limit);
+    SqlStore<K, V> store = newSqlStore(def.name(), def.keyType(), limit,
+        def.expireAfterWrite(TimeUnit.SECONDS));
     Cache<K, ValueHolder<V>> mem = (Cache<K, ValueHolder<V>>)
         defaultFactory.create(def, true)
         .build((CacheLoader<K, V>) new H2CacheImpl.Loader<K, V>(
@@ -209,9 +211,11 @@ class H2CacheFactory implements PersistentCacheFactory, LifecycleListener {
   private <V, K> SqlStore<K, V> newSqlStore(
       String name,
       TypeLiteral<K> keyType,
-      long maxSize) {
+      long maxSize,
+      Long expireAfterWrite) {
     File db = new File(cacheDir, name).getAbsoluteFile();
     String url = "jdbc:h2:" + db.toURI().toString();
-    return new SqlStore<>(url, keyType, maxSize);
+    return new SqlStore<>(url, keyType, maxSize,
+        expireAfterWrite == null ? 0 : expireAfterWrite.longValue());
   }
 }

gerrit-cache-h2/src/main/java/com/google/gerrit/server/cache/h2/H2CacheImpl.java

@@ -313,16 +313,19 @@ public class H2CacheImpl<K, V> extends AbstractLoadingCache<K, V> implements
     private final String url;
     private final KeyType<K> keyType;
     private final long maxSize;
+    private final long expireAfterWrite;
     private final BlockingQueue<SqlHandle> handles;
     private final AtomicLong hitCount = new AtomicLong();
     private final AtomicLong missCount = new AtomicLong();
     private volatile BloomFilter<K> bloomFilter;
     private int estimatedSize;
 
-    SqlStore(String jdbcUrl, TypeLiteral<K> keyType, long maxSize) {
+    SqlStore(String jdbcUrl, TypeLiteral<K> keyType, long maxSize,
+        long expireAfterWrite) {
       this.url = jdbcUrl;
       this.keyType = KeyType.create(keyType);
       this.maxSize = maxSize;
+      this.expireAfterWrite = expireAfterWrite;
 
       int cores = Runtime.getRuntime().availableProcessors();
       int keep = Math.min(cores, 16);
@@ -408,7 +411,7 @@ public class H2CacheImpl<K, V> extends AbstractLoadingCache<K, V> implements
       try {
         c = acquire();
         if (c.get == null) {
-          c.get = c.conn.prepareStatement("SELECT v FROM data WHERE k=?");
+          c.get = c.conn.prepareStatement("SELECT v, created FROM data WHERE k=?");
         }
         keyType.set(c.get, 1, key);
         ResultSet r = c.get.executeQuery();
@@ -418,6 +421,13 @@ public class H2CacheImpl<K, V> extends AbstractLoadingCache<K, V> implements
             return null;
           }
 
+          Timestamp created = r.getTimestamp(2);
+          if (expired(created)) {
+            invalidate(key);
+            missCount.incrementAndGet();
+            return null;
+          }
+
           @SuppressWarnings("unchecked")
           V val = (V) r.getObject(1);
           ValueHolder<V> h = new ValueHolder<>(val);
@@ -438,6 +448,14 @@ public class H2CacheImpl<K, V> extends AbstractLoadingCache<K, V> implements
       }
     }
 
+    private boolean expired(Timestamp created) {
+      if (expireAfterWrite == 0) {
+        return false;
+      }
+      long age = TimeUtil.nowMs() - created.getTime();
+      return 1000 * expireAfterWrite < age;
+    }
+
     private void touch(SqlHandle c, K key) throws SQLException {
       if (c.touch == null) {
         c.touch =c.conn.prepareStatement("UPDATE data SET accessed=? WHERE k=?");
@@ -552,12 +570,14 @@ public class H2CacheImpl<K, V> extends AbstractLoadingCache<K, V> implements
           r = s.executeQuery("SELECT"
               + " k"
               + ",OCTET_LENGTH(k) + OCTET_LENGTH(v)"
+              + ",created"
               + " FROM data"
               + " ORDER BY accessed");
           try {
             while (maxSize < used && r.next()) {
               K key = keyType.get(r, 1);
-              if (mem.getIfPresent(key) != null) {
+              Timestamp created = r.getTimestamp(3);
+              if (mem.getIfPresent(key) != null && !expired(created)) {
                 touch(c, key);
               } else {
                 invalidate(c, key);