a couple more javadocs

dhfs-parent/objects/src/main/java/com/usatiuk/objects/snapshot/Snapshot.java

@@ -8,12 +8,36 @@ import javax.annotation.Nonnull;
 import java.util.List;
 import java.util.Optional;
 
+/**
+ * Interface for a snapshot of a database.
+ * Represents a point-in-time view of a storage, with a unique ID.
+ *
+ * @param <K> the type of the key
+ * @param <V> the type of the value
+ */
 public interface Snapshot<K extends Comparable<K>, V> extends AutoCloseable {
+    /**
+     * Get a list of iterators representing the snapshot.
+     * The iterators have priority: the first one in the list is the highest.
+     * The data type of the iterator is a tombstone: a tombstone represents a deleted value that does not exist anymore.
+     * The list of iterators is intended to be consumed by {@link com.usatiuk.objects.iterators.TombstoneSkippingIterator}
+     *
+     * @return a list of iterators
+     */
     List<CloseableKvIterator<K, MaybeTombstone<V>>> getIterator(IteratorStart start, K key);
 
+    /**
+     * Read an object from the snapshot.
+     * @param name the name of the object
+     * @return an optional containing the object if it exists, or an empty optional if it does not
+     */
     @Nonnull
     Optional<V> readObject(K name);
 
+    /**
+     * Get the ID of the snapshot.
+     * @return the ID of the snapshot
+     */
     long id();
 
     @Override

dhfs-parent/objects/src/main/java/com/usatiuk/objects/stores/CachingObjectPersistentStore.java

@@ -24,6 +24,11 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
 
+/**
+ * CachingObjectPersistentStore is a caching layer for the SerializingObjectPersistentStore
+ * It stores the already deserialized objects in memory.
+ *
+ */
 @ApplicationScoped
 public class CachingObjectPersistentStore {
     private final AtomicReference<Cache> _cache;