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;
