svn commit: r1364778 - /accumulo/branches/1.4/src/core/src/main/java/org/apache/accumulo/core/iterators/WrappingIterator.java

[bi...@apache.org]

Author: billie
Date: Mon Jul 23 20:05:46 2012
New Revision: 1364778

URL: http://svn.apache.org/viewvc?rev=1364778&view=rev
Log:
ACCUMULO-675 improved documentation for WrappingIterator

Modified:
    accumulo/branches/1.4/src/core/src/main/java/org/apache/accumulo/core/iterators/WrappingIterator.java

Modified: accumulo/branches/1.4/src/core/src/main/java/org/apache/accumulo/core/iterators/WrappingIterator.java
URL: http://svn.apache.org/viewvc/accumulo/branches/1.4/src/core/src/main/java/org/apache/accumulo/core/iterators/WrappingIterator.java?rev=1364778&r1=1364777&r2=1364778&view=diff
==============================================================================
--- accumulo/branches/1.4/src/core/src/main/java/org/apache/accumulo/core/iterators/WrappingIterator.java (original)
+++ accumulo/branches/1.4/src/core/src/main/java/org/apache/accumulo/core/iterators/WrappingIterator.java Mon Jul 23 20:05:46 2012
@@ -25,6 +25,15 @@ import org.apache.accumulo.core.data.Key
 import org.apache.accumulo.core.data.Range;
 import org.apache.accumulo.core.data.Value;
 
+/**
+ * A convenience class for implementing iterators that select, but do not modify, entries read from a source iterator. Default implementations exist for all
+ * methods, but {@link #deepCopy} will throw an <code>UnsupportedOperationException</code>.
+ * 
+ * This iterator has some checks in place to enforce the iterator contract. Specifically, it verifies that it has a source iterator and that {@link #seek} has
+ * been called before any data is read. If either of these conditions does not hold true, an <code>IllegalStateException</code> will be thrown. In particular,
+ * this means that <code>getSource().seek</code> and <code>super.seek</code> no longer perform identical actions. Implementors should take note of this and if
+ * <code>seek</code> is overridden, ensure that <code>super.seek</code> is called before data is read.
+ */
 public abstract class WrappingIterator implements SortedKeyValueIterator<Key,Value> {
   
   private SortedKeyValueIterator<Key,Value> source = null;