From 7c842e3c34d2192643d6bef148ff4b7716a173e6 Mon Sep 17 00:00:00 2001
From: Michael McCandless <mikemccand@apache.org>
Date: Tue, 22 Jul 2008 11:14:36 +0000
Subject: [PATCH] LUCENE-1339: make IndexReader incRef and decRef expert public
 methods

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@678716 13f79535-47bb-0310-9956-ffa450edef68
---
 .../org/apache/lucene/index/IndexReader.java  | 29 ++++++++++++++-----
 .../apache/lucene/index/SegmentReader.java    |  4 +--
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/java/org/apache/lucene/index/IndexReader.java b/src/java/org/apache/lucene/index/IndexReader.java
index 23cc1fcdbad..1b4978dae53 100644
--- a/src/java/org/apache/lucene/index/IndexReader.java
+++ b/src/java/org/apache/lucene/index/IndexReader.java
@@ -102,23 +102,38 @@ public abstract class IndexReader {
   }
   
   /**
-   * Increments the refCount of this IndexReader instance. RefCounts are used to determine
-   * when a reader can be closed safely, i. e. as soon as no other IndexReader is referencing
-   * it anymore.
+   * Expert: increments the refCount of this IndexReader
+   * instance.  RefCounts are used to determine when a
+   * reader can be closed safely, i.e. as soon as there are
+   * no more references.  Be sure to always call a
+   * corresponding {@link #decRef}, in a finally clause;
+   * otherwise the reader may never be closed.  Note that
+   * {@link #close} simply calls decRef(), which means that
+   * the IndexReader will not really be closed until {@link
+   * #decRef} has been called for all outstanding
+   * references.
+   *
+   * @see #decRef
    */
-  protected synchronized void incRef() {
+  public synchronized void incRef() {
     assert refCount > 0;
+    ensureOpen();
     refCount++;
   }
 
   /**
-   * Decreases the refCount of this IndexReader instance. If the refCount drops
-   * to 0, then pending changes are committed to the index and this reader is closed.
+   * Expert: decreases the refCount of this IndexReader
+   * instance.  If the refCount drops to 0, then pending
+   * changes (if any) are committed to the index and this
+   * reader is closed.
    * 
    * @throws IOException in case an IOException occurs in commit() or doClose()
+   *
+   * @see #incRef
    */
-  protected synchronized void decRef() throws IOException {
+  public synchronized void decRef() throws IOException {
     assert refCount > 0;
+    ensureOpen();
     if (refCount == 1) {
       commit();
       doClose();
diff --git a/src/java/org/apache/lucene/index/SegmentReader.java b/src/java/org/apache/lucene/index/SegmentReader.java
index 351611f3612..caf90687af2 100644
--- a/src/java/org/apache/lucene/index/SegmentReader.java
+++ b/src/java/org/apache/lucene/index/SegmentReader.java
@@ -138,7 +138,7 @@ class SegmentReader extends DirectoryIndexReader {
    * Increments the RC of this reader, as well as
    * of all norms this reader is using
    */
-  protected synchronized void incRef() {
+  public synchronized void incRef() {
     super.incRef();
     Iterator it = norms.values().iterator();
     while (it.hasNext()) {
@@ -157,7 +157,7 @@ class SegmentReader extends DirectoryIndexReader {
     super.incRef();
   }
 
-  protected synchronized void decRef() throws IOException {
+  public synchronized void decRef() throws IOException {
     super.decRef();
     Iterator it = norms.values().iterator();
     while (it.hasNext()) {