From 89aba400dfc33570c8ac7e20203a2f3d6f588268 Mon Sep 17 00:00:00 2001
From: Robert Muir <rmuir@apache.org>
Date: Thu, 24 May 2012 12:25:33 +0000
Subject: [PATCH] LUCENE-4055: add codecHeader

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/lucene4055@1342223 13f79535-47bb-0310-9956-ffa450edef68
---
 .../lucene/codecs/lucene40/Lucene40SegmentInfoFormat.java   | 6 +++++-
 .../lucene/codecs/lucene40/Lucene40SegmentInfoReader.java   | 4 ++++
 .../lucene/codecs/lucene40/Lucene40SegmentInfoWriter.java   | 2 ++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoFormat.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoFormat.java
index 501856b674e..4f9b485d147 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoFormat.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoFormat.java
@@ -29,12 +29,13 @@ import org.apache.lucene.store.DataOutput; // javadocs
  * <p>
  * Files:
  * <ul>
- *   <li><tt>.si</tt>: SegVersion, SegSize, IsCompoundFile, Diagnostics, Attributes, Files
+ *   <li><tt>.si</tt>: Header, SegVersion, SegSize, IsCompoundFile, Diagnostics, Attributes, Files
  * </ul>
  * </p>
  * Data types:
  * <p>
  * <ul>
+ *   <li>Header --&gt; {@link CodecUtil#writeHeader CodecHeader}</li>
  *   <li>SegSize --&gt; {@link DataOutput#writeInt Int32}</li>
  *   <li>SegVersion --&gt; {@link DataOutput#writeString String}</li>
  *   <li>Files --&gt; {@link DataOutput#writeStringSet Set&lt;String&gt;}</li>
@@ -80,4 +81,7 @@ public class Lucene40SegmentInfoFormat extends SegmentInfoFormat {
   }
 
   public final static String SI_EXTENSION = "si";
+  static final String CODEC_NAME = "Lucene40SegmentInfo";
+  static final int VERSION_START = 0;
+  static final int VERSION_CURRENT = VERSION_START;
 }
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoReader.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoReader.java
index 90f5347ac1f..b7b25070099 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoReader.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoReader.java
@@ -28,6 +28,7 @@ import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.util.CodecUtil;
 import org.apache.lucene.util.IOUtils;
 
 /**
@@ -44,6 +45,9 @@ public class Lucene40SegmentInfoReader extends SegmentInfoReader {
     final IndexInput input = dir.openInput(fileName, context);
     boolean success = false;
     try {
+      CodecUtil.checkHeader(input, Lucene40SegmentInfoFormat.CODEC_NAME,
+                                   Lucene40SegmentInfoFormat.VERSION_START,
+                                   Lucene40SegmentInfoFormat.VERSION_CURRENT);
       final String version = input.readString();
       final int docCount = input.readInt();
       final Map<Integer,Long> normGen = null;
diff --git a/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoWriter.java b/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoWriter.java
index ed2cc077575..6c323d3a884 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoWriter.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/lucene40/Lucene40SegmentInfoWriter.java
@@ -26,6 +26,7 @@ import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
+import org.apache.lucene.util.CodecUtil;
 import org.apache.lucene.util.IOUtils;
 
 /**
@@ -46,6 +47,7 @@ public class Lucene40SegmentInfoWriter extends SegmentInfoWriter {
 
     boolean success = false;
     try {
+      CodecUtil.writeHeader(output, Lucene40SegmentInfoFormat.CODEC_NAME, Lucene40SegmentInfoFormat.VERSION_CURRENT);
       // Write the Lucene version that created this segment, since 3.1
       output.writeString(si.getVersion());
       output.writeInt(si.getDocCount());