From 094a2030f0d802e3481f623649d52c9930ccf17c Mon Sep 17 00:00:00 2001
From: Michael Stack <stack@apache.org>
Date: Fri, 6 Mar 2009 06:47:04 +0000
Subject: [PATCH] HBASE-1245 hfile meta block handling bugs

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@750784 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                   |  1 +
 .../apache/hadoop/hbase/io/hfile/HFile.java   |  5 ++++-
 .../org/apache/hadoop/hbase/util/Bytes.java   |  1 +
 .../hadoop/hbase/io/hfile/TestHFile.java      | 19 ++++++++++++++++---
 4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index 00c1ee63aa6..342db2775ac 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -34,6 +34,7 @@ Release 0.20.0 - Unreleased
    HBASE-1239  in the REST interface does not correctly clear the character
                buffer each iteration-1185  wrong request/sec in the gui
                reporting wrong (Brian Beggs via Stack)
+   HBASE-1245  hfile meta block handling bugs (Ryan Rawson via Stack)
 
   IMPROVEMENTS
    HBASE-1089  Add count of regions on filesystem to master UI; add percentage
diff --git a/src/java/org/apache/hadoop/hbase/io/hfile/HFile.java b/src/java/org/apache/hadoop/hbase/io/hfile/HFile.java
index 609f8cccaf7..c62466a06b8 100644
--- a/src/java/org/apache/hadoop/hbase/io/hfile/HFile.java
+++ b/src/java/org/apache/hadoop/hbase/io/hfile/HFile.java
@@ -713,7 +713,7 @@ public class HFile {
 
       // Read in the metadata index.
       if (trailer.metaIndexCount > 0) {
-        this.metaIndex = BlockIndex.readIndex(this.comparator,
+        this.metaIndex = BlockIndex.readIndex(Bytes.BYTES_RAWCOMPARATOR,
           this.istream, this.trailer.metaIndexOffset, trailer.metaIndexCount);
       }
       this.fileInfoLoaded = true;
@@ -784,6 +784,9 @@ public class HFile {
      * @throws IOException
      */
     public ByteBuffer getMetaBlock(String metaBlockName) throws IOException {
+      if (trailer.metaIndexCount == 0) {
+        return null; // there are no meta blocks
+      }
       if (metaIndex == null) {
         throw new IOException("Meta index not loaded");
       }
diff --git a/src/java/org/apache/hadoop/hbase/util/Bytes.java b/src/java/org/apache/hadoop/hbase/util/Bytes.java
index d2d53b3a135..af717a7d70c 100644
--- a/src/java/org/apache/hadoop/hbase/util/Bytes.java
+++ b/src/java/org/apache/hadoop/hbase/util/Bytes.java
@@ -44,6 +44,7 @@ public class Bytes {
    * Estimate based on study of jhat and jprofiler numbers.
    */
   // JHat says BU is 56 bytes.
+  // SizeOf which uses java.lang.instrument says 24 bytes. (3 longs?)
   public static final int ESTIMATED_HEAP_TAX = 16;
   
   /**
diff --git a/src/test/org/apache/hadoop/hbase/io/hfile/TestHFile.java b/src/test/org/apache/hadoop/hbase/io/hfile/TestHFile.java
index 18151153473..3d869514268 100644
--- a/src/test/org/apache/hadoop/hbase/io/hfile/TestHFile.java
+++ b/src/test/org/apache/hadoop/hbase/io/hfile/TestHFile.java
@@ -169,7 +169,7 @@ public class TestHFile extends TestCase {
 
   private void writeNumMetablocks(Writer writer, int n) {
     for (int i = 0; i < n; i++) {
-      writer.appendMetaBlock("TfileMeta" + i, ("something to test" + i).getBytes());
+      writer.appendMetaBlock("HFileMeta" + i, ("something to test" + i).getBytes());
     }
   }
 
@@ -179,7 +179,7 @@ public class TestHFile extends TestCase {
 
   private void readNumMetablocks(Reader reader, int n) throws IOException {
     for (int i = 0; i < n; i++) {
-      ByteBuffer b = reader.getMetaBlock("TfileMeta" + i);
+      ByteBuffer b = reader.getMetaBlock("HFileMeta" + i);
       byte [] found = Bytes.toBytes(b);
       assertTrue("failed to match metadata", Arrays.equals(
           ("something to test" + i).getBytes(), found));
@@ -191,7 +191,7 @@ public class TestHFile extends TestCase {
   }
 
   private void metablocks(final String compress) throws Exception {
-    Path mFile = new Path(ROOT_DIR, "meta.tfile");
+    Path mFile = new Path(ROOT_DIR, "meta.hfile");
     FSDataOutputStream fout = createFSOutput(mFile);
     Writer writer = new Writer(fout, minBlockSize,
       Compression.getCompressionAlgorithmByName(compress), null, false);
@@ -216,6 +216,19 @@ public class TestHFile extends TestCase {
     metablocks("gz");
   }
   
+  public void testNullMetaBlocks() throws Exception {
+    Path mFile = new Path(ROOT_DIR, "nometa.hfile");
+    FSDataOutputStream fout = createFSOutput(mFile);
+    Writer writer = new Writer(fout, minBlockSize,
+        Compression.Algorithm.NONE, null, false);
+    writer.append("foo".getBytes(), "value".getBytes());
+    writer.close();
+    fout.close();
+    Reader reader = new Reader(fs, mFile, null);
+    reader.loadFileInfo();
+    assertNull(reader.getMetaBlock("non-existant"));
+  }
+  
   /**
    * Make sure the orginals for our compression libs doesn't change on us.
    */